Merge remote-tracking branch 'origin/main' into netmap_progressive_alignment

Main removed the ingress forward rules, so the forwardingRules stash that
carried them to the lazy-exclude finalize is gone with them. The envelope
decode and latestComponents retention move into applySyncPass; persisting
stays with the map-state manager.

client/internal/acl/dispatch_test.go

@@ -0,0 +1,190 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// TestNetworkZeroPrefixIsRoute guards the route-vs-peer dispatch
+// invariant: the backends classify a rule as a peer rule purely by the
+// absence of a destination (neither prefix nor set). A default route
+// (0.0.0.0/0 or ::/0) is a valid prefix and must therefore classify as
+// a route, not collapse into the peer path.
+func TestNetworkZeroPrefixIsRoute(t *testing.T) {
+	for _, p := range []string{"0.0.0.0/0", "::/0", "10.0.0.0/8"} {
+		n := fwmgr.Network{Prefix: netip.MustParsePrefix(p)}
+		assert.True(t, n.IsPrefix(), "%s must report IsPrefix", p)
+		assert.True(t, n.IsPrefix() || n.IsSet(), "%s must classify as a route", p)
+	}
+
+	// A zero-value Network is the only peer-rule shape.
+	var empty fwmgr.Network
+	assert.False(t, empty.IsPrefix(), "zero Network must not be a prefix")
+	assert.False(t, empty.IsSet(), "zero Network must not be a set")
+}
+
+// TestDetermineDestinationAlwaysRoute verifies determineDestination
+// never yields an empty Network for a valid route rule: every branch
+// (static prefix, default route, dynamic with/without domains, with and
+// without a local resolver) produces a destination that classifies as a
+// route. If this regresses, a route rule would be dispatched down the
+// peer path, which matches on source only.
+func TestDetermineDestinationAlwaysRoute(t *testing.T) {
+	v4 := []netip.Prefix{netip.MustParsePrefix("10.0.0.0/24")}
+	v6 := []netip.Prefix{netip.MustParsePrefix("2001:db8::/48")}
+
+	cases := []struct {
+		name     string
+		rule     *mgmProto.RouteFirewallRule
+		resolver bool
+		sources  []netip.Prefix
+	}{
+		{"static prefix", &mgmProto.RouteFirewallRule{Destination: "192.168.0.0/16"}, false, v4},
+		{"static default route", &mgmProto.RouteFirewallRule{Destination: "0.0.0.0/0"}, false, v4},
+		{"dynamic with domains + resolver", &mgmProto.RouteFirewallRule{IsDynamic: true, Domains: []string{"example.com"}}, true, v4},
+		{"dynamic no domains + resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v4},
+		{"dynamic no domains + resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v6},
+		{"dynamic + no local resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v4},
+		{"dynamic + no local resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v6},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			dest, err := determineDestination(tc.rule, tc.resolver, tc.sources)
+			require.NoError(t, err)
+			assert.True(t, dest.IsPrefix() || dest.IsSet(),
+				"destination must classify as a route, got empty Network")
+		})
+	}
+}
+
+// countingFirewall wraps a real firewall.Manager and counts filter-rule
+// add/delete calls so a test can assert how many backing rules the acl
+// manager actually creates and tears down.
+type countingFirewall struct {
+	fwmgr.Manager
+	mu       sync.Mutex
+	addCalls int
+	dels     int
+	ruleIDs  map[fwmgr.RuleID]struct{}
+}
+
+// distinctRules returns the number of distinct backing rules the
+// backend produced. Because the backend dedups identical content,
+// repeated AddFilterRule calls for the same rule resolve to one id.
+func (f *countingFirewall) distinctRules() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.ruleIDs)
+}
+
+func (f *countingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	rule, err := f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+	if err == nil {
+		f.mu.Lock()
+		f.addCalls++
+		if f.ruleIDs == nil {
+			f.ruleIDs = make(map[fwmgr.RuleID]struct{})
+		}
+		if rule != nil {
+			f.ruleIDs[rule.ID()] = struct{}{}
+		}
+		f.mu.Unlock()
+	}
+	return rule, err
+}
+
+func (f *countingFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	err := f.Manager.DeleteFilterRule(r)
+	if err == nil {
+		f.mu.Lock()
+		f.dels++
+		delete(f.ruleIDs, r.ID())
+		f.mu.Unlock()
+	}
+	return err
+}
+
+func newCountingACL(t *testing.T) (*DefaultManager, *countingFirewall, func()) {
+	t.Helper()
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+
+	fw := &countingFirewall{Manager: realFW}
+	cleanup := func() {
+		require.NoError(t, realFW.Close(nil))
+		ctrl.Finish()
+	}
+	return NewDefaultManager(fw), fw, cleanup
+}
+
+// TestDuplicateContentPoliciesShareOneRule verifies the dedup contract
+// the backends rely on: two policies that authorize an identical flow
+// (same selector and sources) collapse to a single backing firewall
+// rule, and that rule survives until BOTH policies are gone. This is
+// why the backend can dedup on add without refcounting on delete: the
+// acl manager's pair key matches the backend's content key, so add and
+// delete stay balanced per content key across full-state reapplies.
+func TestDuplicateContentPoliciesShareOneRule(t *testing.T) {
+	acl, fw, cleanup := newCountingACL(t)
+	defer cleanup()
+
+	ruleA := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.1", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+	ruleB := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-B"),
+		PeerIP:    "10.0.0.1", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+
+	// Both policies present: identical content collapses to one rule.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleA, ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "identical-content policies must produce one backing rule")
+	assert.Equal(t, 1, len(acl.peerRulesPairs), "one content key, one pair")
+
+	// Drop policy A only: the shared rule is still authorized by B, so
+	// nothing is deleted.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "no new backing rule on reapply")
+	assert.Equal(t, 0, fw.dels, "rule must survive while any policy still authorizes it")
+	assert.Equal(t, 1, len(acl.peerRulesPairs))
+
+	// Drop policy B too: now the content key has no authorizer and the
+	// single backing rule is removed exactly once.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}, false)
+	assert.Equal(t, 1, fw.dels, "rule removed once when last policy is gone")
+	assert.Equal(t, 0, len(acl.peerRulesPairs))
+}

client/internal/acl/grouping_test.go

@@ -0,0 +1,318 @@
+package acl
+
+import (
+	"errors"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	"github.com/netbirdio/netbird/shared/netiputil"
+)
+
+// TestGroupPeerRulesPolicyIDSeparates verifies that two FirewallRules
+// with identical selectors but different PolicyIDs do NOT get merged
+// into one group, so each policy's sources merge under its own
+// attribution id. (Identical-content groups may still dedup to one
+// backing rule at the backend; see TestDuplicateContentPoliciesShareOneRule.)
+func TestGroupPeerRulesPolicyIDSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-B"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules with different PolicyIDs must produce separate groups")
+}
+
+// TestGroupPeerRulesFamilySeparates verifies that v4 and v6 rules
+// belonging to the same policy don't merge.
+func TestGroupPeerRulesFamilySeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "2001:db8::1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules of different families must produce separate groups")
+
+	var sawV4, sawV6 bool
+	for _, g := range groups {
+		require.Len(t, g.sources, 1)
+		if g.sources[0].Addr().Is4() {
+			sawV4 = true
+		}
+		if g.sources[0].Addr().Is6() {
+			sawV6 = true
+		}
+	}
+	assert.True(t, sawV4 && sawV6)
+}
+
+// TestGroupPeerRulesSplitsMixedFamilySingleRule verifies that a single
+// FirewallRule carrying both v4 and v6 source prefixes is split into one
+// group per family. Each backend keys a rule to a single family, so a
+// group whose sources span families would mismatch the other family's
+// sources. mgmt normally emits one rule per family; this guards against
+// a mixed-family rule slipping through.
+func TestGroupPeerRulesSplitsMixedFamilySingleRule(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::2")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "mixed-family sources in one rule must split into two groups")
+
+	for _, g := range groups {
+		require.Len(t, g.sources, 2)
+		v6 := prefixIsV6(g.sources[0])
+		for _, s := range g.sources {
+			assert.Equal(t, v6, prefixIsV6(s), "every source in a group must share one family")
+		}
+	}
+}
+
+// TestGroupPeerRulesMergesSameSelector verifies that rules sharing
+// every distinguishing field (policy, family, direction, action,
+// proto, port) collapse into a single multi-source group.
+func TestGroupPeerRulesMergesSameSelector(t *testing.T) {
+	mk := func(peerIP string) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP, //nolint:staticcheck
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		}
+	}
+	rules := []*mgmProto.FirewallRule{mk("10.0.0.1"), mk("10.0.0.2"), mk("10.0.0.3")}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesPortSeparates verifies that PortInfo is part of the
+// selector key: rules differing only in port must not merge, and a
+// single port must not merge with a range. A regression dropping the
+// port from the key would collapse rules for different ports into one.
+func TestGroupPeerRulesPortSeparates(t *testing.T) {
+	mkPort := func(peerIP string, port uint32) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP, //nolint:staticcheck
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Port{Port: port}},
+		}
+	}
+
+	groups, denyErr, err := groupPeerRules([]*mgmProto.FirewallRule{
+		mkPort("10.0.0.1", 80), mkPort("10.0.0.2", 80), mkPort("10.0.0.3", 443),
+	})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules on different ports must not merge")
+
+	rangeRule := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.4", //nolint:staticcheck
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Range_{Range: &mgmProto.PortInfo_Range{Start: 80, End: 90}}},
+	}
+	groups, denyErr, err = groupPeerRules([]*mgmProto.FirewallRule{mkPort("10.0.0.1", 80), rangeRule})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "a single port and a range must not merge")
+}
+
+// TestGroupPeerRulesUsesSourcePrefixesWhenPresent verifies that the
+// new sourcePrefixes wire field is consumed and produces a
+// multi-source group in one shot (no client-side merging needed).
+func TestGroupPeerRulesUsesSourcePrefixesWhenPresent(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.3")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesActionSeparates verifies the obvious: accept
+// and drop rules with the same selector don't merge.
+func TestGroupPeerRulesActionSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_DROP,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2)
+}
+
+// failingDeleteFirewall wraps a real firewall.Manager and forces the
+// next N DeleteFilterRule calls to fail. Used to verify that the acl
+// manager retains rules whose deletion was rejected by the backend,
+// so they get retried on the next ApplyFiltering pass instead of
+// becoming orphans.
+type failingDeleteFirewall struct {
+	fwmgr.Manager
+	failCount int
+}
+
+func (f *failingDeleteFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	if f.failCount > 0 {
+		f.failCount--
+		return errors.New("simulated delete failure")
+	}
+	return f.Manager.DeleteFilterRule(r)
+}
+
+// TestApplyFilteringRetainsRulesOnDeleteFailure verifies that a
+// transient DeleteFilterRule error doesn't make the acl manager
+// forget about a rule. The rule must remain in peerRulesPairs so the
+// next ApplyFiltering pass attempts the delete again.
+func TestApplyFilteringRetainsRulesOnDeleteFailure(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &failingDeleteFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// First pass: install a rule.
+	netmap1 := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			{
+				PolicyID:  []byte("policy-A"),
+				PeerIP:    "10.0.0.1",
+				Direction: mgmProto.RuleDirection_IN,
+				Action:    mgmProto.RuleAction_DROP,
+				Protocol:  mgmProto.RuleProtocol_TCP,
+				Port:      "22",
+			},
+		},
+		FirewallRulesIsEmpty: false,
+	}
+	acl.ApplyFiltering(netmap1, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs), "rule should be installed")
+
+	// Second pass: remove the rule from the map. The backend will
+	// fail the delete; the acl manager must retain the rule.
+	fw.failCount = 1
+	netmap2 := &mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs),
+		"rule must be retained when DeleteFilterRule fails so it gets retried")
+
+	// Third pass: same map, backend no longer fails. The rule
+	// should now succeed in being removed.
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 0, len(acl.peerRulesPairs), "retry should succeed")
+}

client/internal/acl/id/id.go

@@ -5,18 +5,18 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net/netip"
+	"slices"
 	"strconv"
 
 	"github.com/netbirdio/netbird/client/firewall/manager"
 )
 
-type RuleID string
+// RuleID aliases manager.RuleID so existing nbid.RuleID references
+// keep working while the canonical type lives in the firewall package.
+type RuleID = manager.RuleID
 
-func (r RuleID) ID() string {
-	return string(r)
-}
-
-func GenerateRouteRuleKey(
+// GenerateRuleID returns a deterministic content hash identifying a filter rule.
+func GenerateRuleID(
 	sources []netip.Prefix,
 	destination manager.Network,
 	proto manager.Protocol,
@@ -24,6 +24,7 @@ func GenerateRouteRuleKey(
 	dPort *manager.Port,
 	action manager.Action,
 ) RuleID {
+	sources = slices.Clone(sources)
 	manager.SortPrefixes(sources)
 
 	h := sha256.New()

client/internal/acl/legacy_fallback_test.go

@@ -0,0 +1,75 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// sourcesRecordingFirewall wraps a real firewall.Manager and records
+// the source prefixes of every AddFilterRule call.
+type sourcesRecordingFirewall struct {
+	fwmgr.Manager
+	mu      sync.Mutex
+	sources [][]netip.Prefix
+}
+
+func (f *sourcesRecordingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	f.mu.Lock()
+	f.sources = append(f.sources, sources)
+	f.mu.Unlock()
+	return f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+}
+
+// TestLegacyManagementFallbackUsesMatchAnySources verifies the
+// allow-all fallback for old management servers (empty FirewallRules
+// without the FirewallRulesIsEmpty flag) reaches the firewall as /0
+// match-any sources. The fallback rule carries PeerIP 0.0.0.0; if that
+// were converted to a host prefix (0.0.0.0/32) it would match nothing
+// and all peer traffic would be dropped.
+func TestLegacyManagementFallbackUsesMatchAnySources(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &sourcesRecordingFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// Old management: no rules and no FirewallRulesIsEmpty flag.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: false}, false)
+
+	fw.mu.Lock()
+	defer fw.mu.Unlock()
+	require.NotEmpty(t, fw.sources, "legacy fallback must install at least one allow-all rule")
+	for _, sources := range fw.sources {
+		require.NotEmpty(t, sources)
+		for _, p := range sources {
+			assert.Equal(t, 0, p.Bits(), "legacy fallback source %s must be a /0 match-any prefix", p)
+		}
+	}
+}

client/internal/acl/manager.go

@@ -1,8 +1,6 @@
 package acl
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"net/netip"
@@ -24,6 +22,10 @@ import (
 
 var ErrSourceRangesEmpty = errors.New("sources range is empty")
 
+// ErrNoRuleReturned is returned when the firewall backend reports success
+// from AddFilterRule but yields no rule to track.
+var ErrNoRuleReturned = errors.New("backend returned no rule")
+
 // Manager is a ACL rules manager
 type Manager interface {
 	ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool)
@@ -32,19 +34,48 @@ type Manager interface {
 // DefaultManager uses firewall manager to handle
 type DefaultManager struct {
 	firewall           firewall.Manager
-	ipsetCounter       int
 	peerRulesPairs     map[id.RuleID][]firewall.Rule
-	routeRules         map[id.RuleID]struct{}
+	routeRules         map[id.RuleID]firewall.Rule
 	previousConfigHash uint64
 	hasAppliedConfig   bool
 	mutex              sync.Mutex
 }
 
+// peerRuleGroup collapses a set of single-source FirewallRules sharing
+// the same selector into one multi-source rule to push to the backend.
+type peerRuleGroup struct {
+	direction mgmProto.RuleDirection
+	action    mgmProto.RuleAction
+	protocol  mgmProto.RuleProtocol
+	port      *mgmProto.PortInfo
+	// legacyPort is used only when PortInfo is empty (old management).
+	legacyPort string
+	policyID   []byte
+	sources    []netip.Prefix
+}
+
+// peerRuleKey is the comparable selector that decides which single-source
+// rules merge into one group. Rules with an equal key collapse into one
+// multi-source backend rule. PortInfo is flattened into its scalar fields
+// so the key compares by value; policyID keeps policies separate so two
+// policies authorizing different peers don't merge under one attribution.
+type peerRuleKey struct {
+	v6         bool
+	policyID   string
+	direction  mgmProto.RuleDirection
+	action     mgmProto.RuleAction
+	protocol   mgmProto.RuleProtocol
+	legacyPort string
+	port       uint16
+	rangeStart uint16
+	rangeEnd   uint16
+}
+
 func NewDefaultManager(fm firewall.Manager) *DefaultManager {
 	return &DefaultManager{
 		firewall:       fm,
 		peerRulesPairs: make(map[id.RuleID][]firewall.Rule),
-		routeRules:     make(map[id.RuleID]struct{}),
+		routeRules:     make(map[id.RuleID]firewall.Rule),
 	}
 }
 
@@ -88,11 +119,14 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 			time.Since(start), total)
 	}()
 
-	d.applyPeerACLs(networkMap)
+	peerErr := d.applyPeerACLs(networkMap)
+	if peerErr != nil {
+		log.Errorf("apply peer ACLs: %v", peerErr)
+	}
 
 	routeErr := d.applyRouteACLs(networkMap.RoutesFirewallRules, dnsRouteFeatureFlag)
 	if routeErr != nil {
-		log.Errorf("Failed to apply route ACLs: %v", routeErr)
+		log.Errorf("apply route ACLs: %v", routeErr)
 	}
 
 	flushErr := d.firewall.Flush()
@@ -104,7 +138,7 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 	// If applying or flushing failed, leave the previous hash untouched so the
 	// next (possibly identical) update is not skipped and gets a chance to
 	// reconcile the firewall state.
-	if err == nil && routeErr == nil && flushErr == nil {
+	if err == nil && peerErr == nil && routeErr == nil && flushErr == nil {
 		d.previousConfigHash = hash
 		d.hasAppliedConfig = true
 	} else {
@@ -116,11 +150,11 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 // firewall state, so an identical hash means an identical resulting ruleset.
 func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool) (uint64, error) {
 	return hashstructure.Hash(struct {
-		PeerRules            []*mgmProto.FirewallRule
-		PeerRulesIsEmpty     bool
-		RouteRules           []*mgmProto.RouteFirewallRule
-		RouteRulesIsEmpty    bool
-		DNSRouteFeatureFlag  bool
+		PeerRules           []*mgmProto.FirewallRule
+		PeerRulesIsEmpty    bool
+		RouteRules          []*mgmProto.RouteFirewallRule
+		RouteRulesIsEmpty   bool
+		DNSRouteFeatureFlag bool
 	}{
 		PeerRules:           networkMap.GetFirewallRules(),
 		PeerRulesIsEmpty:    networkMap.GetFirewallRulesIsEmpty(),
@@ -135,7 +169,7 @@ func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dns
 	})
 }
 
-func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
+func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) error {
 	rules := networkMap.FirewallRules
 
 	// if we got empty rules list but management not set networkMap.FirewallRulesIsEmpty flag
@@ -144,13 +178,13 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		log.Warn("this peer is connected to a NetBird Management service with an older version. Allowing all traffic from connected peers")
 		rules = append(rules,
 			&mgmProto.FirewallRule{
-				PeerIP:    "0.0.0.0",
+				PeerIP:    "0.0.0.0", //nolint:staticcheck
 				Direction: mgmProto.RuleDirection_IN,
 				Action:    mgmProto.RuleAction_ACCEPT,
 				Protocol:  mgmProto.RuleProtocol_ALL,
 			},
 			&mgmProto.FirewallRule{
-				PeerIP:    "0.0.0.0",
+				PeerIP:    "0.0.0.0", //nolint:staticcheck
 				Direction: mgmProto.RuleDirection_OUT,
 				Action:    mgmProto.RuleAction_ACCEPT,
 				Protocol:  mgmProto.RuleProtocol_ALL,
@@ -158,59 +192,167 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		)
 	}
 
-	newRulePairs := make(map[id.RuleID][]firewall.Rule)
-	ipsetByRuleSelectors := make(map[string]string)
+	// Group incoming single-source rules from management by their
+	// (direction, action, proto, port) selector and merge sources.
+	// One call to the firewall backend per merged rule.
+	// A deny we cannot decode would leave its traffic unblocked, so skip
+	// the whole pass and keep existing rules until the next sync.
+	groups, denyErr, err := groupPeerRules(rules)
+	if denyErr != nil {
+		return fmt.Errorf("decode deny rule sources: %w", denyErr)
+	}
 
-	// TODO: deny rules should be fatal: if a deny rule fails to apply, we must
-	// roll back all allow rules to avoid a fail-open where allowed traffic bypasses
-	// the missing deny. Currently we accumulate errors and continue.
+	newRulePairs := make(map[id.RuleID][]firewall.Rule)
 	var merr *multierror.Error
-	for _, r := range rules {
-		// if this rule is member of rule selection with more than DefaultIPsCountForSet
-		// it's IP address can be used in the ipset for firewall manager which supports it
-		selector := d.getRuleGroupingSelector(r)
-		ipsetName, ok := ipsetByRuleSelectors[selector]
-		if !ok {
-			d.ipsetCounter++
-			ipsetName = fmt.Sprintf("nb%07d", d.ipsetCounter)
-			ipsetByRuleSelectors[selector] = ipsetName
-		}
-		pairID, rulePair, err := d.protoRuleToFirewallRule(r, ipsetName)
-		if err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+	if err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Apply denies first. A deny that fails to install is a security
+	// failure (fail-open), so if any deny errors we roll back the
+	// denies we already installed in this pass and bail out without
+	// installing any accept. Pre-existing rules stay untouched until
+	// the next successful pass clears them.
+	denies, accepts := splitDenyAccept(groups)
+	if err := d.installPeerGroups(denies, newRulePairs, true); err != nil {
+		return fmt.Errorf("install deny rules: %w", err)
+	}
+
+	if err := d.installPeerGroups(accepts, newRulePairs, false); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Tear down rules that disappeared from the networkmap. Any rule
+	// the backend refuses to delete stays in our tracking so it gets
+	// retried on the next ApplyFiltering. Otherwise a transient
+	// delete failure would leak the rule in the firewall until the
+	// process exits.
+	for pairID, rules := range d.peerRulesPairs {
+		if _, ok := newRulePairs[pairID]; ok {
 			continue
 		}
-		if len(rulePair) > 0 {
-			d.peerRulesPairs[pairID] = rulePair
-			newRulePairs[pairID] = rulePair
-		}
-	}
-
-	if merr != nil {
-		log.Errorf("failed to apply %d peer ACL rule(s): %v", merr.Len(), nberrors.FormatErrorOrNil(merr))
-	}
-
-	for pairID, rules := range d.peerRulesPairs {
-		if _, ok := newRulePairs[pairID]; !ok {
-			for _, rule := range rules {
-				if err := d.firewall.DeletePeerRule(rule); err != nil {
-					log.Errorf("failed to delete peer firewall rule: %v", err)
-					continue
-				}
+		var remaining []firewall.Rule
+		for _, rule := range rules {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("delete peer rule, will retry: %w", err))
+				remaining = append(remaining, rule)
 			}
-			delete(d.peerRulesPairs, pairID)
+		}
+		if len(remaining) > 0 {
+			newRulePairs[pairID] = remaining
 		}
 	}
 	d.peerRulesPairs = newRulePairs
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// installPeerGroups applies each group and records the resulting rule
+// pairs in newRulePairs. With atomic set (deny rules), a single failure
+// rolls back every rule installed in this call and returns, leaving the
+// firewall exactly as before: denies are fail-closed and must be applied
+// all-or-nothing. With atomic unset (accept rules), failures are
+// accumulated and the remaining groups still install, so one malformed
+// allow cannot drop every other legitimate allow in the pass.
+func (d *DefaultManager) installPeerGroups(groups []*peerRuleGroup, newRulePairs map[id.RuleID][]firewall.Rule, atomic bool) error {
+	var freshlyInstalled []id.RuleID
+	var merr *multierror.Error
+	for _, g := range groups {
+		pairID, rulePair, err := d.applyPeerGroup(g)
+		if err != nil {
+			if atomic {
+				d.rollbackInstalled(freshlyInstalled)
+				return fmt.Errorf("apply firewall rule: %w", err)
+			}
+			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+			continue
+		}
+		if len(rulePair) == 0 {
+			continue
+		}
+		if _, existed := d.peerRulesPairs[pairID]; !existed {
+			freshlyInstalled = append(freshlyInstalled, pairID)
+		}
+		d.peerRulesPairs[pairID] = rulePair
+		newRulePairs[pairID] = rulePair
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (d *DefaultManager) rollbackInstalled(pairIDs []id.RuleID) {
+	var merr *multierror.Error
+	for _, pairID := range pairIDs {
+		// Keep any rule the backend refuses to delete tracked so it is
+		// retried on the next ApplyFiltering instead of leaking in the
+		// firewall with no tracking left to remove it.
+		var remaining []firewall.Rule
+		for _, rule := range d.peerRulesPairs[pairID] {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("rule %s: %w", pairID, err))
+				remaining = append(remaining, rule)
+			}
+		}
+		if len(remaining) > 0 {
+			d.peerRulesPairs[pairID] = remaining
+		} else {
+			delete(d.peerRulesPairs, pairID)
+		}
+	}
+	if err := nberrors.FormatErrorOrNil(merr); err != nil {
+		log.Errorf("rollback peer rules: %v", err)
+	}
+}
+
+func (d *DefaultManager) applyPeerGroup(g *peerRuleGroup) (id.RuleID, []firewall.Rule, error) {
+	protocol, err := ConvertToFirewallProtocol(g.protocol)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	action, err := convertFirewallAction(g.action)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	port, err := resolveGroupPort(g)
+	if err != nil {
+		return "", nil, err
+	}
+
+	var fwRule firewall.Rule
+	switch g.direction {
+	case mgmProto.RuleDirection_IN:
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, nil, port, action)
+	case mgmProto.RuleDirection_OUT:
+		if d.firewall.IsStateful() {
+			return "", nil, nil
+		}
+		if shouldSkipInvertedRule(protocol, port) {
+			return "", nil, nil
+		}
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, port, nil, action)
+	default:
+		return "", nil, errors.New("invalid direction")
+	}
+
+	if err != nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", err)
+	}
+	if fwRule == nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", ErrNoRuleReturned)
+	}
+
+	// Derive the pair id from the backend rule, like the route path:
+	// the backend dedups identical content, so two policies authorizing
+	// the same flow resolve to the same id and a single backing rule.
+	return fwRule.ID(), []firewall.Rule{fwRule}, nil
 }
 
 func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dynamicResolver bool) error {
-	newRouteRules := make(map[id.RuleID]struct{}, len(rules))
+	newRouteRules := make(map[id.RuleID]firewall.Rule, len(rules))
 	var merr *multierror.Error
 
-	// Apply new rules - firewall manager will return existing rule ID if already present
+	// Apply new rules - firewall manager will return the existing rule if already present
 	for _, rule := range rules {
-		id, err := d.applyRouteACL(rule, dynamicResolver)
+		addedRule, err := d.applyRouteACL(rule, dynamicResolver)
 		if err != nil {
 			if errors.Is(err, ErrSourceRangesEmpty) {
 				log.Debugf("skipping empty sources rule with destination %s: %v", rule.Destination, err)
@@ -219,16 +361,18 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 			}
 			continue
 		}
-		newRouteRules[id] = struct{}{}
+		newRouteRules[addedRule.ID()] = addedRule
 	}
 
-	// Clean up old firewall rules
-	for id := range d.routeRules {
-		if _, exists := newRouteRules[id]; !exists {
-			if err := d.firewall.DeleteRouteRule(id); err != nil {
-				merr = multierror.Append(merr, fmt.Errorf("delete route rule: %w", err))
-			}
-			// implicitly deleted from the map
+	// Tear down old route rules; retain ones the backend refused so a
+	// transient failure doesn't leave orphaned rules in the firewall.
+	for ruleID, rule := range d.routeRules {
+		if _, exists := newRouteRules[ruleID]; exists {
+			continue
+		}
+		if err := d.firewall.DeleteFilterRule(rule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete route rule, will retry: %w", err))
+			newRouteRules[ruleID] = rule
 		}
 	}
 
@@ -236,102 +380,202 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (id.RuleID, error) {
+func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (firewall.Rule, error) {
 	if len(rule.SourceRanges) == 0 {
-		return "", ErrSourceRangesEmpty
+		return nil, ErrSourceRangesEmpty
 	}
 
 	var sources []netip.Prefix
 	for _, sourceRange := range rule.SourceRanges {
 		source, err := netip.ParsePrefix(sourceRange)
 		if err != nil {
-			return "", fmt.Errorf("parse source range: %w", err)
+			return nil, fmt.Errorf("parse source range: %w", err)
 		}
-		sources = append(sources, source)
+		sources = append(sources, firewall.UnmapPrefix(source))
 	}
 
 	destination, err := determineDestination(rule, dynamicResolver, sources)
 	if err != nil {
-		return "", fmt.Errorf("determine destination: %w", err)
+		return nil, fmt.Errorf("determine destination: %w", err)
 	}
 
-	protocol, err := convertToFirewallProtocol(rule.Protocol)
+	protocol, err := ConvertToFirewallProtocol(rule.Protocol)
 	if err != nil {
-		return "", fmt.Errorf("invalid protocol: %w", err)
+		return nil, fmt.Errorf("invalid protocol: %w", err)
 	}
 
 	action, err := convertFirewallAction(rule.Action)
 	if err != nil {
-		return "", fmt.Errorf("invalid action: %w", err)
+		return nil, fmt.Errorf("invalid action: %w", err)
 	}
 
 	dPorts := convertPortInfo(rule.PortInfo)
 
-	addedRule, err := d.firewall.AddRouteFiltering(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
+	addedRule, err := d.firewall.AddFilterRule(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
 	if err != nil {
-		return "", fmt.Errorf("add route rule: %w", err)
+		return nil, fmt.Errorf("add route rule: %w", err)
+	}
+	if addedRule == nil {
+		return nil, fmt.Errorf("add route rule: %w", ErrNoRuleReturned)
 	}
 
-	return id.RuleID(addedRule.ID()), nil
+	return addedRule, nil
 }
 
-func (d *DefaultManager) protoRuleToFirewallRule(
-	r *mgmProto.FirewallRule,
-	ipsetName string,
-) (id.RuleID, []firewall.Rule, error) {
-	ip, err := extractRuleIP(r)
-	if err != nil {
-		return "", nil, err
+// splitDenyAccept partitions groups by action so denies can be
+// applied before accepts. Order within each bucket is preserved.
+func splitDenyAccept(groups []*peerRuleGroup) (denies, accepts []*peerRuleGroup) {
+	for _, g := range groups {
+		if g.action == mgmProto.RuleAction_DROP {
+			denies = append(denies, g)
+		} else {
+			accepts = append(accepts, g)
+		}
+	}
+	return denies, accepts
+}
+
+// groupPeerRules merges single-source rules sharing a selector into
+// multi-source groups. It splits source-decode failures by action:
+// denyErr is non-nil when a deny rule could not be decoded, which is a
+// fail-open risk the caller must treat as fatal for the pass; err
+// carries the tolerable accept-rule failures the caller can log and
+// continue past.
+func groupPeerRules(rules []*mgmProto.FirewallRule) (groups []*peerRuleGroup, denyErr error, err error) {
+	var denyMerr, acceptMerr *multierror.Error
+	byKey := make(map[peerRuleKey]*peerRuleGroup)
+	order := make([]peerRuleKey, 0)
+
+	for _, r := range rules {
+		srcs, decErr := extractRuleSources(r)
+		if decErr != nil {
+			if r.Action == mgmProto.RuleAction_DROP {
+				denyMerr = multierror.Append(denyMerr, decErr)
+			} else {
+				acceptMerr = multierror.Append(acceptMerr, decErr)
+			}
+			continue
+		}
+		// A single FirewallRule normally carries one address family, but
+		// split by family defensively: each backend keys a rule to one
+		// family and would mismatch sources of the other, so a group's
+		// sources must never span families.
+		v4, v6 := splitPrefixesByFamily(srcs)
+		for _, sub := range []struct {
+			isV6    bool
+			sources []netip.Prefix
+		}{{false, v4}, {true, v6}} {
+			if len(sub.sources) == 0 {
+				continue
+			}
+			key := ruleGroupKey(r, sub.isV6)
+			g, ok := byKey[key]
+			if !ok {
+				g = &peerRuleGroup{
+					direction:  r.Direction,
+					action:     r.Action,
+					protocol:   r.Protocol,
+					port:       r.PortInfo,
+					legacyPort: r.Port,
+					policyID:   r.PolicyID,
+				}
+				byKey[key] = g
+				order = append(order, key)
+			}
+			g.sources = append(g.sources, sub.sources...)
+		}
 	}
 
-	protocol, err := convertToFirewallProtocol(r.Protocol)
-	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+	out := make([]*peerRuleGroup, 0, len(order))
+	for _, k := range order {
+		out = append(out, byKey[k])
+	}
+	return out, nberrors.FormatErrorOrNil(denyMerr), nberrors.FormatErrorOrNil(acceptMerr)
+}
+
+func prefixIsV6(p netip.Prefix) bool {
+	return p.Addr().Is6() && !p.Addr().Is4In6()
+}
+
+// splitPrefixesByFamily partitions prefixes into IPv4 and IPv6 groups.
+func splitPrefixesByFamily(prefixes []netip.Prefix) (v4, v6 []netip.Prefix) {
+	for _, p := range prefixes {
+		if prefixIsV6(p) {
+			v6 = append(v6, p)
+		} else {
+			v4 = append(v4, p)
+		}
+	}
+	return v4, v6
+}
+
+// ruleGroupKey builds the selector key for a rule. v6 must reflect the
+// rule's source family: mgmt emits one rule per family and mixing them
+// would break ICMP-variant selection in uspfilter.
+func ruleGroupKey(r *mgmProto.FirewallRule, v6 bool) peerRuleKey {
+	k := peerRuleKey{
+		v6:         v6,
+		policyID:   string(r.PolicyID),
+		direction:  r.Direction,
+		action:     r.Action,
+		protocol:   r.Protocol,
+		legacyPort: r.Port,
+	}
+	if pi := r.PortInfo; pi != nil {
+		k.port = uint16(pi.GetPort())
+		if rng := pi.GetRange(); rng != nil {
+			k.rangeStart = uint16(rng.GetStart())
+			k.rangeEnd = uint16(rng.GetEnd())
+		}
+	}
+	return k
+}
+
+// extractRuleSources returns all source prefixes the rule applies to.
+// New management populates sourcePrefixes; older management sets PeerIP.
+func extractRuleSources(r *mgmProto.FirewallRule) ([]netip.Prefix, error) {
+	if len(r.SourcePrefixes) > 0 {
+		out := make([]netip.Prefix, 0, len(r.SourcePrefixes))
+		for _, raw := range r.SourcePrefixes {
+			addr, err := netiputil.DecodeAddr(raw)
+			if err != nil {
+				return nil, fmt.Errorf("decode source prefix: %w", err)
+			}
+			out = append(out, netip.PrefixFrom(addr.Unmap(), addr.Unmap().BitLen()))
+		}
+		return out, nil
 	}
 
-	action, err := convertFirewallAction(r.Action)
+	peerIP := r.PeerIP //nolint:staticcheck // PeerIP is the legacy source field for old management servers
+	addr, err := netip.ParseAddr(peerIP)
 	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+		return nil, fmt.Errorf("parse peer IP %q: %w", peerIP, err)
 	}
+	addr = addr.Unmap()
+	// An unspecified PeerIP means "any peer" (legacy management
+	// allow-all fallback); only a /0 prefix matches any source in the
+	// backends, a full-length prefix would match nothing.
+	if addr.IsUnspecified() {
+		return []netip.Prefix{netip.PrefixFrom(addr, 0)}, nil
+	}
+	return []netip.Prefix{netip.PrefixFrom(addr, addr.BitLen())}, nil
+}
 
-	var port *firewall.Port
-	if !portInfoEmpty(r.PortInfo) {
-		port = convertPortInfo(r.PortInfo)
-	} else if r.Port != "" {
-		// old version of management, single port
-		value, err := strconv.Atoi(r.Port)
+func resolveGroupPort(g *peerRuleGroup) (*firewall.Port, error) {
+	if !portInfoEmpty(g.port) {
+		return convertPortInfo(g.port), nil
+	}
+	if g.legacyPort != "" {
+		value, err := strconv.ParseUint(g.legacyPort, 10, 16)
 		if err != nil {
-			return "", nil, fmt.Errorf("invalid port: %w", err)
+			return nil, fmt.Errorf("invalid port: %w", err)
 		}
-		port = &firewall.Port{
+		return &firewall.Port{
 			Values: []uint16{uint16(value)},
-		}
+		}, nil
 	}
-
-	ruleID := d.getPeerRuleID(ip, protocol, int(r.Direction), port, action)
-	if rulesPair, ok := d.peerRulesPairs[ruleID]; ok {
-		return ruleID, rulesPair, nil
-	}
-
-	var rules []firewall.Rule
-	switch r.Direction {
-	case mgmProto.RuleDirection_IN:
-		rules, err = d.addInRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	case mgmProto.RuleDirection_OUT:
-		if d.firewall.IsStateful() {
-			return "", nil, nil
-		}
-		// return traffic for outbound connections if firewall is stateless
-		rules, err = d.addOutRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	default:
-		return "", nil, fmt.Errorf("invalid direction, skipping firewall rule")
-	}
-
-	if err != nil {
-		return "", nil, err
-	}
-
-	return ruleID, rules, nil
+	// nolint:nilnil // a nil port legitimately means "no port restriction"
+	return nil, nil
 }
 
 func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
@@ -350,85 +594,9 @@ func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
 	}
 }
 
-func (d *DefaultManager) addInRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, nil, port, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-func (d *DefaultManager) addOutRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	if shouldSkipInvertedRule(protocol, port) {
-		return nil, nil
-	}
-
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, port, nil, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-// getPeerRuleID returns unique ID for the rule based on its parameters.
-func (d *DefaultManager) getPeerRuleID(
-	ip netip.Addr,
-	proto firewall.Protocol,
-	direction int,
-	port *firewall.Port,
-	action firewall.Action,
-) id.RuleID {
-	idStr := ip.String() + string(proto) + strconv.Itoa(direction) + strconv.Itoa(int(action))
-	if port != nil {
-		idStr += port.String()
-	}
-
-	return id.RuleID(hex.EncodeToString(md5.New().Sum([]byte(idStr))))
-}
-
-// getRuleGroupingSelector takes all rule properties except IP address to build selector
-func (d *DefaultManager) getRuleGroupingSelector(rule *mgmProto.FirewallRule) string {
-	return fmt.Sprintf("%v:%v:%v:%s:%v", strconv.Itoa(int(rule.Direction)), rule.Action, rule.Protocol, rule.Port, rule.PortInfo)
-}
-
-
-// extractRuleIP extracts the peer IP from a firewall rule.
-// If sourcePrefixes is populated (new management), decode the first entry and use its address.
-// Otherwise fall back to the deprecated PeerIP string field (old management).
-func extractRuleIP(r *mgmProto.FirewallRule) (netip.Addr, error) {
-	if len(r.SourcePrefixes) > 0 {
-		addr, err := netiputil.DecodeAddr(r.SourcePrefixes[0])
-		if err != nil {
-			return netip.Addr{}, fmt.Errorf("decode source prefix: %w", err)
-		}
-		return addr.Unmap(), nil
-	}
-
-	//nolint:staticcheck // PeerIP used for backward compatibility with old management
-	addr, err := netip.ParseAddr(r.PeerIP)
-	if err != nil {
-		return netip.Addr{}, fmt.Errorf("invalid IP address, skipping firewall rule")
-	}
-	return addr.Unmap(), nil
-}
-
-func convertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
+// ConvertToFirewallProtocol maps a management rule protocol to the
+// firewall protocol type.
+func ConvertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
 	switch protocol {
 	case mgmProto.RuleProtocol_TCP:
 		return firewall.ProtocolTCP, nil

client/internal/acl/manager_test.go

@@ -5,11 +5,12 @@ import (
 	"net/netip"
 	"testing"
 
-	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
 
 	"github.com/netbirdio/netbird/client/firewall"
+	fwmanager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/acl/mocks"
@@ -77,9 +78,9 @@ func TestDefaultManager(t *testing.T) {
 	})
 
 	t.Run("add extra rules", func(t *testing.T) {
-		existedPairs := map[string]struct{}{}
+		existedPairs := map[fwmanager.RuleID]struct{}{}
 		for id := range acl.peerRulesPairs {
-			existedPairs[id.ID()] = struct{}{}
+			existedPairs[id] = struct{}{}
 		}
 
 		// remove first rule
@@ -87,7 +88,7 @@ func TestDefaultManager(t *testing.T) {
 		networkMap.FirewallRules = append(
 			networkMap.FirewallRules,
 			&mgmProto.FirewallRule{
-				PeerIP:    "10.93.0.3",
+				PeerIP:    "10.93.0.3", //nolint:staticcheck
 				Direction: mgmProto.RuleDirection_IN,
 				Action:    mgmProto.RuleAction_DROP,
 				Protocol:  mgmProto.RuleProtocol_ICMP,
@@ -106,7 +107,7 @@ func TestDefaultManager(t *testing.T) {
 		// check that old rule was removed
 		previousCount := 0
 		for id := range acl.peerRulesPairs {
-			if _, ok := existedPairs[id.ID()]; ok {
+			if _, ok := existedPairs[id]; ok {
 				previousCount++
 			}
 		}
@@ -556,12 +557,12 @@ func TestApplyFilteringSkipsUnchangedConfig(t *testing.T) {
 
 func buildNetworkMap(peerRules, routeRules int) *mgmProto.NetworkMap {
 	nm := &mgmProto.NetworkMap{
-		FirewallRulesIsEmpty:      peerRules == 0,
+		FirewallRulesIsEmpty:       peerRules == 0,
 		RoutesFirewallRulesIsEmpty: routeRules == 0,
 	}
 	for i := range peerRules {
 		nm.FirewallRules = append(nm.FirewallRules, &mgmProto.FirewallRule{
-			PeerIP:    fmt.Sprintf("10.%d.%d.%d", i>>16&0xff, i>>8&0xff, i&0xff),
+			PeerIP:    fmt.Sprintf("10.%d.%d.%d", i>>16&0xff, i>>8&0xff, i&0xff), //nolint:staticcheck
 			Direction: mgmProto.RuleDirection_IN,
 			Action:    mgmProto.RuleAction_ACCEPT,
 			Protocol:  mgmProto.RuleProtocol_TCP,

client/internal/acl/mocks/iface_mapper.go

@@ -7,7 +7,7 @@ package mocks
 import (
 	reflect "reflect"
 
-	gomock "github.com/golang/mock/gomock"
+	gomock "go.uber.org/mock/gomock"
 	wgdevice "golang.zx2c4.com/wireguard/device"
 
 	"github.com/netbirdio/netbird/client/iface/device"

client/internal/auth/account_match_test.go

@@ -0,0 +1,113 @@
+package auth
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTokenInfoMatchesAccount(t *testing.T) {
+	tests := []struct {
+		name  string
+		token TokenInfo
+		hint  string
+		match bool
+	}{
+		{
+			name:  "same account",
+			token: TokenInfo{EmailClaim: "user@example.com"},
+			hint:  "user@example.com",
+			match: true,
+		},
+		{
+			name:  "different account",
+			token: TokenInfo{EmailClaim: "other@example.com"},
+			hint:  "user@example.com",
+			match: false,
+		},
+		{
+			name:  "case differences are the same account",
+			token: TokenInfo{EmailClaim: "User@Example.com"},
+			hint:  "user@example.com",
+			match: true,
+		},
+		{
+			name:  "no hint leaves the choice to the IdP",
+			token: TokenInfo{EmailClaim: "other@example.com"},
+			hint:  "",
+			match: true,
+		},
+		{
+			name:  "token without an email claim is not judged",
+			token: TokenInfo{EmailClaim: ""},
+			hint:  "user@example.com",
+			match: true,
+		},
+		{
+			name:  "name fallback does not trigger matching",
+			token: TokenInfo{Email: "Some One"},
+			hint:  "user@example.com",
+			match: true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.match, tc.token.MatchesAccount(tc.hint))
+		})
+	}
+}
+
+func TestParseEmailFromIDToken(t *testing.T) {
+	tests := []struct {
+		name          string
+		claims        map[string]interface{}
+		wantValue     string
+		wantFromEmail bool
+		wantErr       bool
+	}{
+		{
+			name:          "email claim",
+			claims:        map[string]interface{}{"email": "user@example.com", "name": "Some One"},
+			wantValue:     "user@example.com",
+			wantFromEmail: true,
+		},
+		{
+			name:      "name fallback",
+			claims:    map[string]interface{}{"name": "Some One"},
+			wantValue: "Some One",
+		},
+		{
+			name:    "neither claim present",
+			claims:  map[string]interface{}{"sub": "abc"},
+			wantErr: true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			value, fromEmailClaim, err := parseEmailFromIDToken(idTokenWithClaims(t, tc.claims))
+			if tc.wantErr {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+			assert.Equal(t, tc.wantValue, value)
+			assert.Equal(t, tc.wantFromEmail, fromEmailClaim)
+		})
+	}
+}
+
+func TestRetryFlowForAccountUnsupportedFlow(t *testing.T) {
+	assert.Nil(t, RetryFlowForAccount(&DeviceAuthorizationFlow{}))
+}
+
+func idTokenWithClaims(t *testing.T, claims map[string]interface{}) string {
+	t.Helper()
+	payload, err := json.Marshal(claims)
+	require.NoError(t, err)
+	return "header." + base64.RawURLEncoding.EncodeToString(payload) + ".signature"
+}

client/internal/auth/auth.go

@@ -3,6 +3,7 @@ package auth
 import (
 	"context"
 	"net/url"
+	"strings"
 	"sync"
 	"time"
 
@@ -21,6 +22,25 @@ import (
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 )
 
+// peerLoginExpiredMsg is the exact phrase the management server returns
+// when a previously SSO-enrolled peer's login has expired. Sourced from
+// shared/management/status/error.go (NewPeerLoginExpiredError). Matched
+// by substring so a future server-side rewording that keeps the phrase
+// still triggers the friendly fallback in Login().
+const peerLoginExpiredMsg = "peer login has expired"
+
+// errSetupKeyOnSSOExpiredPeer replaces the raw management error when the
+// user runs `netbird login -k <setup-key>` against a peer that was
+// originally enrolled via SSO. Wrapped in a PermissionDenied gRPC status
+// so callers' existing isPermissionDenied / isAuthError checks still
+// classify it correctly (early-exit from retry backoff, StatusNeedsLogin
+// in the server state machine).
+var errSetupKeyOnSSOExpiredPeer = status.Error(
+	codes.PermissionDenied,
+	"this peer was originally enrolled via SSO and its session has expired. "+
+		"Setup keys can only enrol new peers — run `netbird up` (interactive SSO) to re-login.",
+)
+
 // Auth manages authentication operations with the management server
 // It maintains a long-lived connection and automatically handles reconnection with backoff
 type Auth struct {
@@ -83,7 +103,7 @@ func (a *Auth) IsSSOSupported(ctx context.Context) (bool, error) {
 
 	err := a.withRetry(ctx, func(client *mgm.GrpcClient) error {
 		// Try PKCE flow first
-		_, err := a.getPKCEFlow(client)
+		_, err := a.getPKCEFlow(client, false)
 		if err == nil {
 			supportsSSO = true
 			return nil
@@ -116,28 +136,43 @@ func (a *Auth) IsSSOSupported(ctx context.Context) (bool, error) {
 	return supportsSSO, err
 }
 
-// GetOAuthFlow returns an OAuth flow (PKCE or Device) using the existing management connection
-// This avoids creating a new connection to the management server
-func (a *Auth) GetOAuthFlow(ctx context.Context, forceDeviceAuth bool) (OAuthFlow, error) {
+// GetOAuthFlow returns an OAuth flow (PKCE or Device) using the existing management connection.
+// This avoids creating a new connection to the management server.
+//
+// sessionExtend marks the flow as renewing an existing peer's session rather than
+// logging one in; the server needs it to rule out a silent authorization that the
+// IdP could answer from another account. See PKCEAuthorizationFlowRequest.
+func (a *Auth) GetOAuthFlow(ctx context.Context, forceDeviceAuth bool, sessionExtend bool, hint string) (OAuthFlow, error) {
 	var flow OAuthFlow
-	var err error
 
-	err = a.withRetry(ctx, func(client *mgm.GrpcClient) error {
+	err := a.withRetry(ctx, func(client *mgm.GrpcClient) error {
 		if forceDeviceAuth {
-			flow, err = a.getDeviceFlow(client)
-			return err
+			deviceFlow, err := a.getDeviceFlow(client)
+			if err != nil {
+				return err
+			}
+			deviceFlow.SetLoginHint(hint)
+			flow = deviceFlow
+			return nil
 		}
 
 		// Try PKCE flow first
-		flow, err = a.getPKCEFlow(client)
+		pkceFlow, err := a.getPKCEFlow(client, sessionExtend)
 		if err != nil {
 			// If PKCE not supported, try Device flow
 			if s, ok := status.FromError(err); ok && (s.Code() == codes.NotFound || s.Code() == codes.Unimplemented) {
-				flow, err = a.getDeviceFlow(client)
-				return err
+				deviceFlow, err := a.getDeviceFlow(client)
+				if err != nil {
+					return err
+				}
+				deviceFlow.SetLoginHint(hint)
+				flow = deviceFlow
+				return nil
 			}
 			return err
 		}
+		pkceFlow.SetLoginHint(hint)
+		flow = pkceFlow
 		return nil
 	})
 
@@ -184,6 +219,15 @@ func (a *Auth) Login(ctx context.Context, setupKey string, jwtToken string) (err
 			log.Debugf("peer registration required")
 			_, err = a.registerPeer(client, ctx, setupKey, jwtToken, pubSSHKey)
 			if err != nil {
+				// The peer pub-key is already on file with the management
+				// server (originally enrolled via SSO) and the session has
+				// expired. The setup-key path can only enrol new peers, so
+				// retrying with -k will keep failing. Replace the raw mgm
+				// message with an actionable hint that tells the user to
+				// re-authenticate via SSO instead.
+				if setupKey != "" && jwtToken == "" && isPeerLoginExpired(err) {
+					err = errSetupKeyOnSSOExpiredPeer
+				}
 				isAuthError = isPermissionDenied(err)
 				return err
 			}
@@ -200,8 +244,8 @@ func (a *Auth) Login(ctx context.Context, setupKey string, jwtToken string) (err
 }
 
 // getPKCEFlow retrieves PKCE authorization flow configuration and creates a flow instance
-func (a *Auth) getPKCEFlow(client *mgm.GrpcClient) (*PKCEAuthorizationFlow, error) {
-	protoFlow, err := client.GetPKCEAuthorizationFlow()
+func (a *Auth) getPKCEFlow(client *mgm.GrpcClient, sessionExtend bool) (*PKCEAuthorizationFlow, error) {
+	protoFlow, err := client.GetPKCEAuthorizationFlow(sessionExtend)
 	if err != nil {
 		if s, ok := status.FromError(err); ok && s.Code() == codes.NotFound {
 			log.Warnf("server couldn't find pkce flow, contact admin: %v", err)
@@ -322,11 +366,13 @@ func (a *Auth) setSystemInfoFlags(info *system.Info) {
 		a.config.BlockLANAccess,
 		a.config.BlockInbound,
 		a.config.DisableIPv6,
+		a.config.SyncMessageVersion,
 		a.config.EnableSSHRoot,
 		a.config.EnableSSHSFTP,
 		a.config.EnableSSHLocalPortForwarding,
 		a.config.EnableSSHRemotePortForwarding,
 		a.config.DisableSSHAuth,
+		a.config.RemoteJobsAllowed,
 	)
 }
 
@@ -473,3 +519,16 @@ func isLoginNeeded(err error) bool {
 func isRegistrationNeeded(err error) bool {
 	return isPermissionDenied(err)
 }
+
+// isPeerLoginExpired reports whether err is the management server's
+// "peer login has expired" PermissionDenied response. Used by Login to
+// detect the case where the caller passed a setup-key but the peer is
+// actually an SSO-enrolled record whose session needs refreshing — the
+// setup-key path cannot help there.
+func isPeerLoginExpired(err error) bool {
+	if !isPermissionDenied(err) {
+		return false
+	}
+	s, _ := status.FromError(err)
+	return strings.Contains(s.Message(), peerLoginExpiredMsg)
+}

client/internal/auth/auth_test.go

@@ -0,0 +1,80 @@
+package auth
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func TestIsPeerLoginExpired(t *testing.T) {
+	cases := []struct {
+		name string
+		err  error
+		want bool
+	}{
+		{
+			name: "nil",
+			err:  nil,
+			want: false,
+		},
+		{
+			name: "plain error (not a gRPC status)",
+			err:  errors.New("network read: connection reset"),
+			want: false,
+		},
+		{
+			name: "PermissionDenied with different message",
+			err:  status.Error(codes.PermissionDenied, "user is blocked"),
+			want: false,
+		},
+		{
+			name: "Unauthenticated with the expected phrase",
+			// Wrong status code — must still return false.
+			err:  status.Error(codes.Unauthenticated, "peer login has expired, please log in once more"),
+			want: false,
+		},
+		{
+			name: "exact server message",
+			err:  status.Error(codes.PermissionDenied, "peer login has expired, please log in once more"),
+			want: true,
+		},
+		{
+			name: "phrase as substring",
+			// Future-proofing: if mgm reworords but keeps the phrase,
+			// the friendly fallback must still kick in.
+			err:  status.Error(codes.PermissionDenied, "session refused: peer login has expired (account=foo)"),
+			want: true,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := isPeerLoginExpired(tc.err); got != tc.want {
+				t.Fatalf("isPeerLoginExpired(%v) = %v, want %v", tc.err, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestErrSetupKeyOnSSOExpiredPeer(t *testing.T) {
+	// Sentinel must surface as PermissionDenied so the upstream
+	// isPermissionDenied / isAuthError checks classify it correctly
+	// (short-circuit retry backoff, set StatusNeedsLogin).
+	if !isPermissionDenied(errSetupKeyOnSSOExpiredPeer) {
+		t.Fatalf("errSetupKeyOnSSOExpiredPeer must be a PermissionDenied gRPC error")
+	}
+
+	// Message must actually mention SSO and `netbird up` so it is
+	// actionable for the end user. Loose substring checks keep the
+	// test resilient to copy edits.
+	s, _ := status.FromError(errSetupKeyOnSSOExpiredPeer)
+	msg := strings.ToLower(s.Message())
+	for _, want := range []string{"sso", "netbird up"} {
+		if !strings.Contains(msg, want) {
+			t.Errorf("sentinel message should contain %q, got %q", want, s.Message())
+		}
+	}
+}

client/internal/auth/device_flow.go

@@ -259,12 +259,18 @@ func (d *DeviceAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowIn
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()
 
+	log.Infof("device flow: waiting for user authorization, polling token endpoint every %s, code expires in %s", interval, timeout)
+
+	start := time.Now()
+	polls := 0
+
 	for {
 		select {
 		case <-waitCtx.Done():
 			return TokenInfo{}, waitCtx.Err()
 		case <-ticker.C:
 
+			polls++
 			tokenResponse, err := d.requestToken(info)
 			if err != nil {
 				return TokenInfo{}, fmt.Errorf("parsing token response failed with error: %v", err)
@@ -272,10 +278,12 @@ func (d *DeviceAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowIn
 
 			if tokenResponse.Error != "" {
 				if tokenResponse.Error == "authorization_pending" {
+					log.Tracef("device flow: authorization still pending after poll %d", polls)
 					continue
 				} else if tokenResponse.Error == "slow_down" {
 					interval += (3 * time.Second)
 					ticker.Reset(interval)
+					log.Infof("device flow: IdP requested slow_down, polling interval increased to %s", interval)
 					continue
 				}
 
@@ -291,11 +299,25 @@ func (d *DeviceAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowIn
 				UseIDToken:   d.providerConfig.UseIDToken,
 			}
 
-			err = isValidAccessToken(tokenInfo.GetTokenToUse(), d.providerConfig.Audience)
+			err = validateTokenAudience(tokenInfo.GetTokenToUse(), d.providerConfig.Audience)
 			if err != nil {
 				return TokenInfo{}, fmt.Errorf("validate access token failed with error: %v", err)
 			}
 
+			// Same as the PKCE flow: the account the token belongs to is what
+			// callers store to send back as the login_hint. Without it a client
+			// driven through the device flow — Android TV and tvOS — never binds
+			// an account to its profile and every later login goes out blind.
+			if email, fromEmailClaim, err := parseEmailFromIDToken(tokenInfo.IDToken); err != nil {
+				log.Warnf("failed to parse email from ID token: %v", err)
+			} else {
+				tokenInfo.Email = email
+				if fromEmailClaim {
+					tokenInfo.EmailClaim = email
+				}
+			}
+
+			log.Infof("device flow: user authorization confirmed after %d polls in %s", polls, time.Since(start).Round(time.Second))
 			return tokenInfo, err
 		}
 	}

client/internal/auth/oauth.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"runtime"
+	"strings"
 
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc/codes"
@@ -25,6 +26,14 @@ type HTTPClient interface {
 	Do(req *http.Request) (*http.Response, error)
 }
 
+// accountPromptForcer is implemented by the PKCE flow only. The device code
+// flow has no equivalent: RFC 8628 defines no prompt parameter, and the user
+// confirms the code on a page that shows which account signs in, so a silent
+// wrong-account answer is not the failure mode there.
+type accountPromptForcer interface {
+	ForceAccountPrompt()
+}
+
 // AuthFlowInfo holds information for the OAuth 2.0  authorization flow
 type AuthFlowInfo struct { //nolint:revive
 	DeviceCode              string `json:"device_code"`
@@ -49,6 +58,23 @@ type TokenInfo struct {
 	ExpiresIn    int    `json:"expires_in"`
 	UseIDToken   bool   `json:"-"`
 	Email        string `json:"-"`
+	EmailClaim   string `json:"-"`
+}
+
+// MatchesAccount reports whether the token belongs to the account a profile is
+// bound to. A hint the IdP could not have acted on — no hint stored, or a token
+// that carried no email claim — is reported as a match: the check exists to catch a
+// login answered from the wrong account, not to block one it cannot judge.
+//
+// The comparison is case-insensitive. Local-parts are case-sensitive per RFC
+// 5321, but no IdP in practice issues two accounts differing only in case, and
+// an IdP that echoes a differently-cased address would otherwise fail every
+// login.
+func (t TokenInfo) MatchesAccount(hint string) bool {
+	if hint == "" || t.EmailClaim == "" {
+		return true
+	}
+	return strings.EqualFold(t.EmailClaim, hint)
 }
 
 // GetTokenToUse returns either the access or id token based on UseIDToken field
@@ -63,19 +89,22 @@ func shouldUseDeviceFlow(force bool, isUnixDesktopClient bool) bool {
 	return force || (runtime.GOOS == "linux" || runtime.GOOS == "freebsd") && !isUnixDesktopClient
 }
 
-// NewOAuthFlow initializes and returns the appropriate OAuth flow based on the management configuration
+// NewOAuthFlow initializes and returns the appropriate OAuth flow based on the management configuration.
 //
 // It starts by initializing the PKCE.If this process fails, it resorts to the Device Code Flow,
 // and if that also fails, the authentication process is deemed unsuccessful
 //
-// On Linux distros without desktop environment support, it only tries to initialize the Device Code Flow
-// forceDeviceCodeFlow can be used to skip PKCE and go directly to Device Code Flow (e.g., for Android TV)
-func NewOAuthFlow(ctx context.Context, config *profilemanager.Config, isUnixDesktopClient bool, forceDeviceCodeFlow bool, hint string) (OAuthFlow, error) {
+// On Linux distros without desktop environment support, it only tries to initialize the Device Code Flow.
+// forceDeviceCodeFlow can be used to skip PKCE and go directly to Device Code Flow (e.g., for Android TV).
+//
+// sessionExtend marks the flow as renewing an existing peer's session rather than
+// logging one in. See PKCEAuthorizationFlowRequest for what the server makes of it.
+func NewOAuthFlow(ctx context.Context, config *profilemanager.Config, isUnixDesktopClient bool, forceDeviceCodeFlow bool, hint string, sessionExtend bool) (OAuthFlow, error) {
 	if shouldUseDeviceFlow(forceDeviceCodeFlow, isUnixDesktopClient) {
 		return authenticateWithDeviceCodeFlow(ctx, config, hint)
 	}
 
-	pkceFlow, err := authenticateWithPKCEFlow(ctx, config, hint)
+	pkceFlow, err := authenticateWithPKCEFlow(ctx, config, hint, sessionExtend)
 	if err != nil {
 		log.Debugf("failed to initialize pkce authentication with error: %v\n", err)
 		log.Debug("falling back to device code flow")
@@ -85,21 +114,19 @@ func NewOAuthFlow(ctx context.Context, config *profilemanager.Config, isUnixDesk
 }
 
 // authenticateWithPKCEFlow initializes the Proof Key for Code Exchange flow auth flow
-func authenticateWithPKCEFlow(ctx context.Context, config *profilemanager.Config, hint string) (OAuthFlow, error) {
+func authenticateWithPKCEFlow(ctx context.Context, config *profilemanager.Config, hint string, sessionExtend bool) (OAuthFlow, error) {
 	authClient, err := NewAuth(ctx, config.PrivateKey, config.ManagementURL, config)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create auth client: %v", err)
 	}
 	defer authClient.Close()
 
-	pkceFlowInfo, err := authClient.getPKCEFlow(authClient.client)
+	pkceFlowInfo, err := authClient.getPKCEFlow(authClient.client, sessionExtend)
 	if err != nil {
 		return nil, fmt.Errorf("getting pkce authorization flow info failed with error: %v", err)
 	}
 
-	if hint != "" {
-		pkceFlowInfo.SetLoginHint(hint)
-	}
+	pkceFlowInfo.SetLoginHint(hint)
 
 	return pkceFlowInfo, nil
 }
@@ -127,9 +154,25 @@ func authenticateWithDeviceCodeFlow(ctx context.Context, config *profilemanager.
 		}
 	}
 
-	if hint != "" {
-		deviceFlowInfo.SetLoginHint(hint)
-	}
+	deviceFlowInfo.SetLoginHint(hint)
 
 	return deviceFlowInfo, nil
 }
+
+// RetryFlowForAccount returns a flow that asks the IdP to re-authenticate, for
+// a login answered with an account other than the one hinted. Returns nil when
+// the flow cannot ask — the caller then proceeds with the token it has.
+//
+// Proceeding rather than failing is deliberate. The hint is an email that may
+// simply have changed since it was stored, and refusing the login would lock a
+// user out of their own profile over a rename. The retry gives the account a
+// chance to be corrected; the server still rejects a token that does not own
+// the peer.
+func RetryFlowForAccount(flow OAuthFlow) OAuthFlow {
+	forcer, ok := flow.(accountPromptForcer)
+	if !ok {
+		return nil
+	}
+	forcer.ForceAccountPrompt()
+	return flow
+}

client/internal/auth/pending_flow.go

@@ -0,0 +1,89 @@
+package auth
+
+import (
+	"context"
+	"sync"
+	"time"
+)
+
+// PendingFlow stores an in-progress OAuth flow between the RPC that
+// initiates it (returns the verification URI to the UI) and the RPC
+// that waits for the user to complete it. The flow handle, the
+// device-code info, and the absolute expiry are kept together so the
+// waiting RPC can validate the device code and reuse the same flow.
+//
+// PendingFlow is safe for concurrent use; callers must not access the
+// stored fields directly.
+type PendingFlow struct {
+	mu         sync.Mutex
+	flow       OAuthFlow
+	info       AuthFlowInfo
+	expiresAt  time.Time
+	waitCancel context.CancelFunc
+}
+
+// NewPendingFlow returns an empty PendingFlow ready to be populated by Set.
+func NewPendingFlow() *PendingFlow {
+	return &PendingFlow{}
+}
+
+// Set stores the flow and its authorization info, computing the absolute
+// expiry from info.ExpiresIn (seconds, as returned by the IdP).
+func (p *PendingFlow) Set(flow OAuthFlow, info AuthFlowInfo) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.flow = flow
+	p.info = info
+	p.expiresAt = time.Now().Add(time.Duration(info.ExpiresIn) * time.Second)
+}
+
+// Get returns the stored flow, info, and whether a flow is currently
+// pending. Returns (nil, zero, false) after Clear or before Set.
+func (p *PendingFlow) Get() (OAuthFlow, AuthFlowInfo, bool) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.flow == nil {
+		return nil, AuthFlowInfo{}, false
+	}
+	return p.flow, p.info, true
+}
+
+// ExpiresAt returns the absolute expiry of the pending flow. Returns
+// the zero time when no flow is pending.
+func (p *PendingFlow) ExpiresAt() time.Time {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.expiresAt
+}
+
+// SetWaitCancel records the cancel function for the goroutine currently
+// blocked in WaitToken so a new RequestAuth can preempt it.
+func (p *PendingFlow) SetWaitCancel(cancel context.CancelFunc) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.waitCancel = cancel
+}
+
+// CancelWait invokes and clears the stored wait-cancel, if any. Safe to
+// call when no wait is in progress.
+func (p *PendingFlow) CancelWait() {
+	p.mu.Lock()
+	cancel := p.waitCancel
+	p.waitCancel = nil
+	p.mu.Unlock()
+	if cancel != nil {
+		cancel()
+	}
+}
+
+// Clear resets the pending flow to empty. Any stored wait-cancel is
+// dropped without being invoked — call CancelWait first if the waiting
+// goroutine must be stopped.
+func (p *PendingFlow) Clear() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.flow = nil
+	p.info = AuthFlowInfo{}
+	p.expiresAt = time.Time{}
+	p.waitCancel = nil
+}

client/internal/auth/pkce_flow.go

@@ -87,10 +87,11 @@ func validatePKCEConfig(config *PKCEAuthProviderConfig) error {
 // PKCEAuthorizationFlow implements the OAuthFlow interface for
 // the Authorization Code Flow with PKCE.
 type PKCEAuthorizationFlow struct {
-	providerConfig PKCEAuthProviderConfig
-	state          string
-	codeVerifier   string
-	oAuthConfig    *oauth2.Config
+	providerConfig     PKCEAuthProviderConfig
+	state              string
+	codeVerifier       string
+	oAuthConfig        *oauth2.Config
+	forceAccountPrompt bool
 }
 
 // NewPKCEAuthorizationFlow returns new PKCE authorization code flow.
@@ -153,11 +154,16 @@ func (p *PKCEAuthorizationFlow) RequestAuthInfo(ctx context.Context) (AuthFlowIn
 		oauth2.SetAuthURLParam("code_challenge", codeChallenge),
 		oauth2.SetAuthURLParam("audience", p.providerConfig.Audience),
 	}
+	forceAccountPrompt := p.forceAccountPrompt
+	p.forceAccountPrompt = false
+
 	if !p.providerConfig.DisablePromptLogin {
-		switch p.providerConfig.LoginFlag {
-		case common.LoginFlagPromptLogin:
+		switch {
+		case forceAccountPrompt:
 			params = append(params, oauth2.SetAuthURLParam("prompt", "login"))
-		case common.LoginFlagMaxAge0:
+		case p.providerConfig.LoginFlag == common.LoginFlagPromptLogin:
+			params = append(params, oauth2.SetAuthURLParam("prompt", "login"))
+		case p.providerConfig.LoginFlag == common.LoginFlagMaxAge0:
 			params = append(params, oauth2.SetAuthURLParam("max_age", "0"))
 		}
 	}
@@ -178,6 +184,20 @@ func (p *PKCEAuthorizationFlow) SetLoginHint(hint string) {
 	p.providerConfig.LoginHint = hint
 }
 
+// ForceAccountPrompt makes the next authorization request ask the IdP to
+// re-authenticate instead of answering from the session it already holds. Used
+// to retry a login that came back for an account other than the one hinted.
+//
+// The next RequestAuthInfo consumes the flag, so a flow that outlives its retry
+// goes back to the configured behaviour instead of re-authenticating forever.
+//
+// DisablePromptLogin still wins: it is set for IdPs that break on prompt=login,
+// where retrying with it would replace a wrong-account login with one that
+// cannot complete at all.
+func (p *PKCEAuthorizationFlow) ForceAccountPrompt() {
+	p.forceAccountPrompt = true
+}
+
 // WaitToken waits for the OAuth token in the PKCE Authorization Flow.
 // It starts an HTTP server to receive the OAuth token callback and waits for the token or an error.
 // Once the token is received, it is converted to TokenInfo and validated before returning.
@@ -188,6 +208,8 @@ func (p *PKCEAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowInfo
 	waitCtx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
+	log.Infof("pkce flow: waiting for authorization callback on %s, timeout %s", p.oAuthConfig.RedirectURL, timeout)
+
 	tokenChan := make(chan *oauth2.Token, 1)
 	errChan := make(chan error, 1)
 
@@ -221,6 +243,7 @@ func (p *PKCEAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowInfo
 func (p *PKCEAuthorizationFlow) startServer(server *http.Server, tokenChan chan<- *oauth2.Token, errChan chan<- error) {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+		log.Infof("pkce flow: received authorization callback from IdP")
 		cert := p.providerConfig.ClientCertPair
 		if cert != nil {
 			tr := &http.Transport{
@@ -271,11 +294,18 @@ func (p *PKCEAuthorizationFlow) handleRequest(req *http.Request) (*oauth2.Token,
 		return nil, fmt.Errorf("authentication failed: missing code")
 	}
 
-	return p.oAuthConfig.Exchange(
+	exchangeStart := time.Now()
+	token, err := p.oAuthConfig.Exchange(
 		req.Context(),
 		code,
 		oauth2.SetAuthURLParam("code_verifier", p.codeVerifier),
 	)
+	if err != nil {
+		return nil, err
+	}
+
+	log.Infof("pkce flow: authorization code exchanged for token in %s", time.Since(exchangeStart).Round(time.Millisecond))
+	return token, nil
 }
 
 func (p *PKCEAuthorizationFlow) parseOAuthToken(token *oauth2.Token) (TokenInfo, error) {
@@ -296,48 +326,52 @@ func (p *PKCEAuthorizationFlow) parseOAuthToken(token *oauth2.Token) (TokenInfo,
 		audience = p.providerConfig.ClientID
 	}
 
-	if err := isValidAccessToken(tokenInfo.GetTokenToUse(), audience); err != nil {
+	if err := validateTokenAudience(tokenInfo.GetTokenToUse(), audience); err != nil {
 		return TokenInfo{}, fmt.Errorf("authentication failed: invalid access token - %w", err)
 	}
 
-	email, err := parseEmailFromIDToken(tokenInfo.IDToken)
+	email, fromEmailClaim, err := parseEmailFromIDToken(tokenInfo.IDToken)
 	if err != nil {
 		log.Warnf("failed to parse email from ID token: %v", err)
 	} else {
 		tokenInfo.Email = email
+		if fromEmailClaim {
+			tokenInfo.EmailClaim = email
+		}
 	}
 
 	return tokenInfo, nil
 }
 
-func parseEmailFromIDToken(token string) (string, error) {
+// parseEmailFromIDToken extracts the email (or name) claim from an ID token
+// without verifying its signature. The value is best-effort: it prefills the
+// login hint and is displayed. Account matching (see MatchesAccount) only uses
+// it when it came from the email claim, which fromEmailClaim reports. It never
+// grants anything — the authoritative identity is established server-side from
+// the signature-verified token.
+func parseEmailFromIDToken(token string) (value string, fromEmailClaim bool, err error) {
 	parts := strings.Split(token, ".")
 	if len(parts) < 2 {
-		return "", fmt.Errorf("invalid token format")
+		return "", false, fmt.Errorf("invalid token format")
 	}
 
 	data, err := base64.RawURLEncoding.DecodeString(parts[1])
 	if err != nil {
-		return "", fmt.Errorf("failed to decode payload: %w", err)
+		return "", false, fmt.Errorf("failed to decode payload: %w", err)
 	}
 	var claims map[string]interface{}
 	if err := json.Unmarshal(data, &claims); err != nil {
-		return "", fmt.Errorf("json unmarshal error: %w", err)
+		return "", false, fmt.Errorf("json unmarshal error: %w", err)
 	}
 
-	var email string
-	if emailValue, ok := claims["email"].(string); ok {
-		email = emailValue
-	} else {
-		val, ok := claims["name"].(string)
-		if ok {
-			email = val
-		} else {
-			return "", fmt.Errorf("email or name field not found in token payload")
-		}
+	if email, ok := claims["email"].(string); ok {
+		return email, true, nil
+	}
+	if name, ok := claims["name"].(string); ok {
+		return name, false, nil
 	}
 
-	return email, nil
+	return "", false, fmt.Errorf("email or name field not found in token payload")
 }
 
 func createCodeChallenge(codeVerifier string) string {

client/internal/auth/pkce_flow_test.go

@@ -76,6 +76,32 @@ func TestPromptLogin(t *testing.T) {
 	}
 }
 
+func TestForceAccountPromptAppliesOnlyToTheRetry(t *testing.T) {
+	config := PKCEAuthProviderConfig{
+		ClientID:              "test-client-id",
+		Audience:              "test-audience",
+		TokenEndpoint:         "https://test-token-endpoint.com/token",
+		Scope:                 "openid email profile",
+		AuthorizationEndpoint: "https://test-auth-endpoint.com/authorize",
+		RedirectURLs:          []string{"http://127.0.0.1:33992/"},
+		UseIDToken:            true,
+		LoginFlag:             mgm.LoginFlagNone,
+	}
+	pkce, err := NewPKCEAuthorizationFlow(config)
+	require.NoError(t, err)
+
+	pkce.ForceAccountPrompt()
+
+	retry, err := pkce.RequestAuthInfo(context.Background())
+	require.NoError(t, err)
+	require.Contains(t, retry.VerificationURIComplete, "prompt=login")
+
+	next, err := pkce.RequestAuthInfo(context.Background())
+	require.NoError(t, err)
+	require.NotContains(t, next.VerificationURIComplete, "prompt=login",
+		"the forced prompt outlived the retry it was armed for")
+}
+
 func TestIsPortInExcludedRange(t *testing.T) {
 	tests := []struct {
 		name            string

client/internal/auth/sessionwatch/event.go

@@ -0,0 +1,82 @@
+package sessionwatch
+
+import (
+	"strconv"
+	"time"
+)
+
+// internal event kinds are no longer exposed: the watcher drives the Sink
+// directly (NotifyStateChange on deadline change/clear, PublishEvent at
+// each warning lead). Tests use a mock Sink to observe what the watcher
+// emits.
+
+// Metadata keys attached by the daemon to session-warning SystemEvents.
+// The UI tray reads these to build a locale-aware notification without
+// relying on the daemon's locale-less UserMessage string, and to
+// disambiguate the T-WarningLead notification from the T-FinalWarningLead
+// fallback that auto-opens the SessionAboutToExpire dialog.
+const (
+	// MetaSessionWarning is set to "true" on both warning events (T-10 and
+	// T-2) so the UI can detect a session-warning SystemEvent without
+	// matching on the message text. Use MetaSessionFinal to distinguish
+	// the two.
+	MetaSessionWarning = "session_warning"
+	// MetaSessionFinal is set to "true" on the T-FinalWarningLead event
+	// only. Consumers that need to auto-open the SessionAboutToExpire
+	// dialog gate on this; T-WarningLead events leave the field unset.
+	MetaSessionFinal = "session_final_warning"
+	// MetaSessionExpiresAt carries the absolute UTC deadline encoded with
+	// FormatExpiresAt; consumers must decode with ParseExpiresAt so a
+	// future format change stays a single edit.
+	MetaSessionExpiresAt = "session_expires_at"
+	// MetaSessionLeadMinutes carries the lead in whole minutes (WarningLead
+	// for the T-10 event, FinalWarningLead for the T-2 event) so the UI
+	// can show "expires in ~N minutes" without hardcoding either constant.
+	MetaSessionLeadMinutes = "lead_minutes"
+	// MetaSessionDeadlineRejected is attached to the ERROR/AUTHENTICATION
+	// SystemEvent the daemon emits when it discards a deadline from the
+	// management server (pre-epoch, too far in the future, or past the
+	// clock-skew tolerance). The value is the rejection reason string.
+	// userMessage is left empty; the UI detects the event via this key
+	// and builds a localized notification — same pattern as the session
+	// warnings above.
+	MetaSessionDeadlineRejected = "session_deadline_rejected"
+)
+
+// expiresAtLayout is the wire format used for MetaSessionExpiresAt.
+// Producer and consumers both go through FormatExpiresAt/ParseExpiresAt
+// so this layout stays a single source of truth.
+const expiresAtLayout = time.RFC3339
+
+// FormatExpiresAt encodes a deadline for MetaSessionExpiresAt. Always
+// emits UTC so a consumer in another timezone reads the same wall-clock
+// deadline.
+func FormatExpiresAt(t time.Time) string {
+	return t.UTC().Format(expiresAtLayout)
+}
+
+// ParseExpiresAt decodes the MetaSessionExpiresAt value back to a UTC
+// time. Returns an error when the field is empty or malformed; the
+// caller decides whether to fall back (zero value) or propagate.
+func ParseExpiresAt(s string) (time.Time, error) {
+	t, err := time.Parse(expiresAtLayout, s)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return t.UTC(), nil
+}
+
+// FormatLeadMinutes encodes a lead duration for MetaSessionLeadMinutes
+// as the integer count of whole minutes. Sub-minute residuals are
+// truncated — the field is informational ("expires in ~N minutes") and
+// fractional minutes don't change what the UI displays.
+func FormatLeadMinutes(d time.Duration) string {
+	return strconv.Itoa(int(d / time.Minute))
+}
+
+// ParseLeadMinutes decodes a MetaSessionLeadMinutes value. Returns 0
+// and the parse error for malformed input; consumers that prefer a
+// silent fallback can simply ignore the error.
+func ParseLeadMinutes(s string) (int, error) {
+	return strconv.Atoi(s)
+}

client/internal/auth/sessionwatch/watcher.go

@@ -0,0 +1,487 @@
+// Package sessionwatch tracks the SSO session expiry deadline that the
+// management server publishes via LoginResponse / SyncResponse and fires
+// two warning events at fixed lead times before expiry: an interactive
+// T-WarningLead notification and a dismiss-gated T-FinalWarningLead
+// fallback dialog.
+//
+// The deadline is an absolute wall-clock instant, so the watcher compares
+// it against the wall clock on a ticker rather than arming a relative
+// timer for it. A relative timer runs on the monotonic clock, which does
+// not advance while a device is suspended: it fires once that much awake
+// time has passed, which can be long after the deadline, and nothing
+// re-evaluates when the device wakes up. Polling makes every tick after a
+// resume (or after an NTP correction) see the real remaining time.
+//
+// The watcher is idempotent: Update may be called as often as the network
+// map snapshots arrive. Repeating the same deadline is a no-op; a new
+// deadline starts a fresh warning cycle.
+//
+// Warning firing is edge-detected. Each unique deadline value publishes
+// each warning at most once.
+package sessionwatch
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	cProto "github.com/netbirdio/netbird/client/proto"
+)
+
+const (
+	maxPastHorizon = 30 * 24 * time.Hour
+
+	// maxDeadlineHorizon caps how far in the future an accepted deadline
+	// can sit. A timestamp beyond this is almost certainly a protocol
+	// glitch, and silently tracking a 100-year deadline would hide the bug.
+	maxDeadlineHorizon = 10 * 365 * 24 * time.Hour
+
+	// defaultEvalInterval is how often the tracked deadline is compared
+	// against the wall clock. The leads are minutes, so a coarse tick costs
+	// nothing in accuracy and keeps the wakeup cheap on battery-powered
+	// devices.
+	defaultEvalInterval = 10 * time.Second
+
+	// WarningLead is how far before expiry the first (interactive)
+	// warning fires. Drives the T-10 OS notification with
+	// Extend/Dismiss actions.
+	WarningLead = 10 * time.Minute
+
+	// FinalWarningLead is how far before expiry the fallback final
+	// warning fires. Drives the auto-opened SessionAboutToExpire dialog,
+	// but only when the user has not dismissed the T-WarningLead warning
+	// for the same deadline. Must be strictly less than WarningLead.
+	FinalWarningLead = 2 * time.Minute
+)
+
+var (
+	// ErrDeadlineBeforeEpoch is returned by Update when the supplied
+	// deadline pre-dates 1970-01-01.
+	ErrDeadlineBeforeEpoch = errors.New("session deadline before unix epoch")
+
+	// ErrDeadlineTooFarFuture is returned by Update when the supplied
+	// deadline is more than maxDeadlineHorizon in the future.
+	ErrDeadlineTooFarFuture = errors.New("session deadline too far in the future")
+
+	// ErrDeadlineInPast is returned by Update when the supplied deadline
+	// is more than maxPastHorizon in the past.
+	ErrDeadlineInPast = errors.New("session deadline in the past")
+)
+
+// StatusRecorder is the side-effect surface the watcher drives on every
+// state transition. Production wires this to peer.Status (SetSessionExpiresAt
+// for deadline change/clear, PublishEvent for the two warnings); tests pass
+// a fake recorder so the same surface is observable without an engine.
+//
+// While the watcher runs, it owns the deadline propagated to the recorder:
+// every set, clear and sanity-check rejection routes the value through
+// SetSessionExpiresAt, so the SubscribeStatus snapshot the UI reads can
+// never drift from the watcher's timer state. (SetSessionExpiresAt fans
+// out its own state-change notification, so no separate notify is needed.)
+// The recorder is server-scoped and outlives this engine-scoped watcher;
+// Close deliberately leaves the recorder value in place so transient engine
+// restarts don't blank it — the client run loop clears it on real teardown.
+//
+// PublishEvent's signature mirrors peer.Status.PublishEvent: the watcher
+// composes the metadata internally so the wire format (MetaSession*) is
+// owned by sessionwatch, not the caller.
+type StatusRecorder interface {
+	SetSessionExpiresAt(deadline time.Time)
+	PublishEvent(
+		severity cProto.SystemEvent_Severity,
+		category cProto.SystemEvent_Category,
+		message string,
+		userMessage string,
+		metadata map[string]string,
+	)
+}
+
+// Watcher observes the latest session deadline and fires two warnings
+// before it expires: the interactive T-WarningLead notification, and the
+// fallback T-FinalWarningLead dialog (suppressed when the user dismissed
+// the first one for the same deadline). Safe for concurrent use.
+type Watcher struct {
+	lead         time.Duration
+	finalLead    time.Duration
+	interval     time.Duration
+	deadlineOnly bool // record the deadline, leave the warnings to the caller
+
+	mu           sync.Mutex
+	current      time.Time
+	firedAt      time.Time // deadline value the T-WarningLead warning last published for
+	finalFiredAt time.Time // deadline value the T-FinalWarningLead warning last published for
+	dismissedAt  time.Time // deadline value the user dismissed via Dismiss(); gates the final warning
+	announcedAt  time.Time // deadline value the recorder has been told about; gates publishing
+	closed       bool
+	recorder     StatusRecorder
+	nowFn        func() time.Time
+	stop         chan struct{} // closed to stop the evaluation loop; nil while it is not running
+	done         chan struct{} // closed by the loop on its way out
+	wake         chan struct{} // buffered nudge asking the loop to evaluate before its next tick
+}
+
+// New returns a watcher with the package defaults WarningLead and
+// FinalWarningLead. Pass nil for recorder to silence side effects (handy
+// in unit tests that exercise sanity checks without observing the publish
+// path).
+func New(recorder StatusRecorder) *Watcher {
+	return NewWithLeads(WarningLead, FinalWarningLead, recorder)
+}
+
+// NewWithLeads returns a watcher with custom lead times. Useful for tests.
+// final must be strictly less than lead; otherwise the final warning takes
+// over the whole warning window and the interactive notification never
+// shows. A zero final lead disables the final warning entirely (see
+// evaluate), leaving the interactive one as the only warning.
+func NewWithLeads(lead, final time.Duration, recorder StatusRecorder) *Watcher {
+	return &Watcher{
+		lead:      lead,
+		finalLead: final,
+		interval:  defaultEvalInterval,
+		recorder:  recorder,
+		nowFn:     time.Now,
+	}
+}
+
+// NewDeadlineOnly returns a watcher that validates and records deadlines
+// but publishes no warnings about them, and runs no evaluation loop to
+// decide. Used where the deadline is handed on to something that schedules
+// the warnings itself, such as the Android app.
+func NewDeadlineOnly(recorder StatusRecorder) *Watcher {
+	w := New(recorder)
+	w.deadlineOnly = true
+	return w
+}
+
+// Update sets the latest deadline. Pass the zero time to clear (e.g. when
+// a Sync push from the server omits the field because login expiration
+// was disabled).
+//
+// Same-value updates are no-ops. A different non-zero value resets the
+// "already fired" guards and starts a fresh warning cycle, evaluated
+// immediately so a deadline that already sits inside a warning window
+// warns without waiting for the next tick. A deadline already in the past
+// (within maxPastHorizon) is recorded as-is and warns nothing: the session
+// has expired and consumers render it that way.
+//
+// Returns one of the sentinel Err* values when the deadline fails the
+// sanity checks (pre-epoch, far future, or past beyond maxPastHorizon).
+// In every error case the watcher first clears its state so it stays
+// consistent with what the caller will push into its other sinks (e.g.
+// applySessionDeadline forces a zero deadline into the status recorder
+// after a non-nil error).
+func (w *Watcher) Update(deadline time.Time) error {
+	w.mu.Lock()
+	if w.closed {
+		w.mu.Unlock()
+		return nil
+	}
+
+	if deadline.IsZero() {
+		w.clearLocked()
+		return nil
+	}
+
+	now := w.nowFn()
+	switch {
+	case deadline.Before(time.Unix(0, 0)):
+		w.clearLocked()
+		return fmt.Errorf("%w: %v", ErrDeadlineBeforeEpoch, deadline)
+	case deadline.After(now.Add(maxDeadlineHorizon)):
+		w.clearLocked()
+		return fmt.Errorf("%w: %v", ErrDeadlineTooFarFuture, deadline)
+	case deadline.Before(now.Add(-maxPastHorizon)):
+		w.clearLocked()
+		return fmt.Errorf("%w: %v (now=%v)", ErrDeadlineInPast, deadline, now)
+	}
+
+	if deadline.Equal(w.current) {
+		w.mu.Unlock()
+		return nil
+	}
+
+	w.current = deadline
+	// Reset every per-deadline guard so a refreshed deadline starts a fresh
+	// warning cycle: both edge triggers and the user Dismiss decision
+	// (the user agreed to the old deadline expiring; a new deadline
+	// restarts the contract).
+	w.firedAt = time.Time{}
+	w.finalFiredAt = time.Time{}
+	w.dismissedAt = time.Time{}
+	w.announcedAt = time.Time{}
+
+	// Poll every accepted deadline, including one that reads as already
+	// expired: the clock may be running ahead of real time and get
+	// corrected later, and evaluate ignores a deadline that has genuinely
+	// passed anyway.
+	if !w.deadlineOnly {
+		w.startPollLocked()
+	}
+	recorder := w.recorder
+	w.mu.Unlock()
+	if recorder != nil {
+		recorder.SetSessionExpiresAt(deadline)
+	}
+	log.Infof("auth session deadline set to: %s (in %s)", deadline.Format(time.RFC3339), time.Until(deadline).Round(time.Second))
+
+	// Open the gate only once the recorder knows the new deadline, so a
+	// warning that refers to it can never reach consumers before the state
+	// change itself. A tick landing in between finds the gate shut.
+	w.mu.Lock()
+	if w.closed || !w.current.Equal(deadline) {
+		w.mu.Unlock()
+		return nil
+	}
+	w.announcedAt = deadline
+	wake := w.wake
+	w.mu.Unlock()
+
+	// Hand the evaluation to the loop rather than running it here, so a
+	// deadline that already sits inside a warning window is published at
+	// once without this goroutine ever touching the recorder.
+	if wake != nil {
+		select {
+		case wake <- struct{}{}:
+		default:
+		}
+	}
+	return nil
+}
+
+// Deadline returns the most recently observed deadline. Zero when no
+// deadline is currently tracked.
+func (w *Watcher) Deadline() time.Time {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.current
+}
+
+// Dismiss records the user's "Dismiss" action against the current deadline
+// and suppresses the final warning for that deadline. Idempotent: repeated
+// calls are no-ops. A subsequent Update with a fresh deadline resets the
+// dismissal so the final-warning cycle starts over.
+//
+// No-op when the watcher holds no deadline or has been closed.
+func (w *Watcher) Dismiss() {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed || w.current.IsZero() {
+		return
+	}
+	if w.dismissedAt.Equal(w.current) {
+		return
+	}
+	w.dismissedAt = w.current
+	log.Infof("auth session final-warning dismissed for deadline %s", w.current.Format(time.RFC3339))
+}
+
+// Close stops the evaluation loop and waits for it to exit. Update calls
+// after Close are ignored. The recorder keeps its deadline: the watcher is
+// engine-scoped and closes on every engine restart (network change,
+// sleep/wake, stream errors) while the SSO deadline stays valid across
+// those, so clearing here would blank the UI's "expires in" row on every
+// transient reconnect. The client run loop clears the server-scoped
+// recorder when it exits for real (Down, profile switch, permanent login
+// failure).
+func (w *Watcher) Close() {
+	w.mu.Lock()
+	if w.closed {
+		// A concurrent Close is already tearing down. w.done outlives it,
+		// so this caller waits for the same loop rather than returning
+		// while a warning is still on its way to the recorder.
+		done := w.done
+		w.mu.Unlock()
+		if done != nil {
+			<-done
+		}
+		return
+	}
+	w.closed = true
+	w.current = time.Time{}
+	w.firedAt = time.Time{}
+	w.finalFiredAt = time.Time{}
+	w.dismissedAt = time.Time{}
+	w.announcedAt = time.Time{}
+	// Copy the channels out before releasing the lock: the loop takes w.mu
+	// on every tick, so waiting for it while holding the lock would
+	// deadlock. w.done stays on the receiver for the branch above.
+	stop, done := w.stop, w.done
+	w.stop, w.wake = nil, nil
+	w.mu.Unlock()
+
+	if stop == nil {
+		return
+	}
+	close(stop)
+	<-done
+}
+
+// clearLocked drops the tracked deadline and notifies the recorder so
+// downstream consumers (SubscribeStatus stream, UI) drop their anchor.
+// The caller must hold w.mu; this helper releases it before invoking
+// the recorder.
+func (w *Watcher) clearLocked() {
+	if w.current.IsZero() {
+		w.mu.Unlock()
+		return
+	}
+	w.current = time.Time{}
+	w.firedAt = time.Time{}
+	w.finalFiredAt = time.Time{}
+	w.dismissedAt = time.Time{}
+	w.announcedAt = time.Time{}
+	recorder := w.recorder
+	w.mu.Unlock()
+	if recorder != nil {
+		recorder.SetSessionExpiresAt(time.Time{})
+	}
+	log.Infof("auth session deadline cleared")
+}
+
+// startPollLocked starts the evaluation loop unless it is already
+// running. The loop starts lazily on the first accepted deadline, so a
+// client whose server never publishes a session expiry never pays for a
+// ticker, and it runs until Close: the watcher is engine-scoped, and a
+// cleared deadline is normally followed by a fresh one on the next sync.
+// Caller must hold w.mu.
+func (w *Watcher) startPollLocked() {
+	if w.stop != nil {
+		return
+	}
+	stop := make(chan struct{})
+	done := make(chan struct{})
+	wake := make(chan struct{}, 1)
+	w.stop, w.done, w.wake = stop, done, wake
+	go w.poll(stop, done, wake, w.interval)
+}
+
+// poll re-evaluates the tracked deadline every interval, and as soon as a
+// new deadline is announced. It is the only caller of evaluate, so Close
+// waiting for it to exit is enough to know no warning is still on its way
+// to the recorder. Its channels and interval are passed in rather than
+// read off the receiver, so Close can clear them without racing it.
+func (w *Watcher) poll(stop <-chan struct{}, done chan<- struct{}, wake <-chan struct{}, interval time.Duration) {
+	defer close(done)
+
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-stop:
+			return
+		case <-wake:
+			w.evaluate()
+		case <-ticker.C:
+			w.evaluate()
+		}
+	}
+}
+
+// evaluate compares the tracked deadline against the wall clock and
+// publishes whichever warning the remaining time calls for. Inside the
+// final-warning window the interactive warning is stale, so the final one
+// is published in its place: a device that resumes there never saw the
+// T-WarningLead notification.
+func (w *Watcher) evaluate() {
+	w.mu.Lock()
+	if w.closed || w.deadlineOnly || w.current.IsZero() {
+		w.mu.Unlock()
+		return
+	}
+
+	deadline := w.current
+	if !w.announcedAt.Equal(deadline) {
+		// Update is still on its way to the recorder with this deadline.
+		w.mu.Unlock()
+		return
+	}
+	// Round(0) strips the monotonic reading so the comparison is wall
+	// clock on both sides, whether the deadline came off the wire or from
+	// a caller that derived it from time.Now.
+	remaining := deadline.Round(0).Sub(w.nowFn().Round(0))
+
+	switch {
+	case remaining <= 0:
+		// Already expired: the post-mortem SessionExpired flow owns it.
+		w.mu.Unlock()
+	case w.finalLead > 0 && remaining <= w.finalLead:
+		w.publishFinalLocked(deadline, remaining)
+	case remaining <= w.lead:
+		w.publishWarningLocked(deadline, remaining)
+	default:
+		w.mu.Unlock()
+	}
+}
+
+// publishWarningLocked emits the interactive T-WarningLead warning, at
+// most once per deadline value. Caller must hold w.mu; this helper
+// releases it.
+func (w *Watcher) publishWarningLocked(deadline time.Time, remaining time.Duration) {
+	if w.firedAt.Equal(deadline) {
+		w.mu.Unlock()
+		return
+	}
+	w.firedAt = deadline
+	recorder := w.recorder
+	w.mu.Unlock()
+	if recorder == nil {
+		return
+	}
+	log.Infof("auth session expiry soon warning fired for deadline %s (in %s)",
+		deadline.Format(time.RFC3339), remaining.Round(time.Second))
+	publishWarning(recorder, deadline, false)
+}
+
+// publishFinalLocked emits the final warning, at most once per deadline
+// value and never once the user dismissed that deadline. It marks the
+// interactive warning as handled too: the final window is open, so a
+// "expires in WarningLead minutes" notification would be wrong. Caller
+// must hold w.mu; this helper releases it.
+func (w *Watcher) publishFinalLocked(deadline time.Time, remaining time.Duration) {
+	if w.finalFiredAt.Equal(deadline) || w.dismissedAt.Equal(deadline) {
+		w.mu.Unlock()
+		return
+	}
+	w.firedAt = deadline
+	w.finalFiredAt = deadline
+	recorder := w.recorder
+	w.mu.Unlock()
+	if recorder == nil {
+		return
+	}
+	log.Infof("auth session final-warning fired for deadline %s (in %s)",
+		deadline.Format(time.RFC3339), remaining.Round(time.Second))
+	publishWarning(recorder, deadline, true)
+}
+
+// publishWarning composes the SystemEvent for a watcher-fired warning and
+// pushes it through the recorder. Severity is CRITICAL on both — bypassing
+// the user's Notifications toggle is deliberate: missing the warning
+// window forces the post-mortem SessionExpired flow (tunnel torn down,
+// lock icon, manual re-login), which is the UX we are trying to avoid.
+func publishWarning(recorder StatusRecorder, deadline time.Time, final bool) {
+	lead := WarningLead
+	message := "session expiry warning"
+	meta := map[string]string{
+		MetaSessionWarning:   "true",
+		MetaSessionExpiresAt: FormatExpiresAt(deadline),
+	}
+	if final {
+		lead = FinalWarningLead
+		message = "session expiry final warning"
+		meta[MetaSessionFinal] = "true"
+	}
+	meta[MetaSessionLeadMinutes] = FormatLeadMinutes(lead)
+
+	recorder.PublishEvent(
+		cProto.SystemEvent_CRITICAL,
+		cProto.SystemEvent_AUTHENTICATION,
+		message,
+		"",
+		meta,
+	)
+}

client/internal/auth/sessionwatch/watcher_test.go

@@ -0,0 +1,919 @@
+package sessionwatch
+
+import (
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	cProto "github.com/netbirdio/netbird/client/proto"
+)
+
+// fakeRecorder satisfies StatusRecorder and records every call so tests
+// can observe what the watcher emits. SetSessionExpiresAt and PublishEvent
+// land in the same ordered events slice (with the Kind distinguishing
+// them) so tests that care about ordering still work. lastDeadline holds
+// the most recent value passed to SetSessionExpiresAt so tests can assert
+// the recorder ended up cleared/set as expected.
+type fakeRecorder struct {
+	mu           sync.Mutex
+	events       []event
+	lastDeadline time.Time
+	// setDelay stalls SetSessionExpiresAt, widening the window in which a
+	// concurrent evaluation could publish a warning out of order.
+	setDelay time.Duration
+}
+
+type eventKind int
+
+const (
+	stateChange eventKind = iota
+	publish
+)
+
+type event struct {
+	kind eventKind
+	// Set only for publish events.
+	severity cProto.SystemEvent_Severity
+	category cProto.SystemEvent_Category
+	message  string
+	meta     map[string]string
+}
+
+// SetSessionExpiresAt mirrors peer.Status: a same-value write is a no-op,
+// a real change records the new value and fans out a state-change (the
+// production recorder calls notifyStateChange internally). The baseline
+// is the zero time, so an initial clear before any deadline is set emits
+// nothing — matching the real recorder.
+func (r *fakeRecorder) SetSessionExpiresAt(deadline time.Time) {
+	r.mu.Lock()
+	delay := r.setDelay
+	r.mu.Unlock()
+	// Stall without the lock held, so a concurrent publish can still record.
+	time.Sleep(delay)
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.lastDeadline.Equal(deadline) {
+		return
+	}
+	r.lastDeadline = deadline
+	r.events = append(r.events, event{kind: stateChange})
+}
+
+func (r *fakeRecorder) deadline() time.Time {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return r.lastDeadline
+}
+
+func (r *fakeRecorder) PublishEvent(
+	severity cProto.SystemEvent_Severity,
+	category cProto.SystemEvent_Category,
+	message string,
+	_ string,
+	metadata map[string]string,
+) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.events = append(r.events, event{
+		kind:     publish,
+		severity: severity,
+		category: category,
+		message:  message,
+		meta:     metadata,
+	})
+}
+
+func (r *fakeRecorder) snapshot() []event {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	out := make([]event, len(r.events))
+	copy(out, r.events)
+	return out
+}
+
+func (e event) isFinalWarning() bool {
+	return e.kind == publish && e.meta[MetaSessionFinal] == "true"
+}
+
+func (e event) isWarning() bool {
+	return e.kind == publish && e.meta[MetaSessionWarning] == "true" && e.meta[MetaSessionFinal] != "true"
+}
+
+func countWhere(events []event, pred func(event) bool) int {
+	n := 0
+	for _, e := range events {
+		if pred(e) {
+			n++
+		}
+	}
+	return n
+}
+
+func waitForEvents(t *testing.T, r *fakeRecorder, want int) []event {
+	t.Helper()
+	deadline := time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		if got := r.snapshot(); len(got) >= want {
+			return got
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	got := r.snapshot()
+	t.Fatalf("timed out waiting for %d events, got %d: %+v", want, len(got), got)
+	return nil
+}
+
+// testInterval keeps the ticker-driven tests fast; the leads they use are
+// in the same millisecond scale.
+const testInterval = 2 * time.Millisecond
+
+// newWatcher builds a watcher with the final warning disabled (finalLead=0),
+// matching the lead-only behaviour the pre-final-warning tests assume.
+func newWatcher(lead time.Duration, r *fakeRecorder) *Watcher {
+	return newWatcherWithLeads(lead, 0, r)
+}
+
+// newWatcherWithLeads builds a watcher that evaluates on testInterval. The
+// interval is set before Update, so the evaluation loop does not exist yet
+// and the write cannot race it.
+func newWatcherWithLeads(lead, final time.Duration, r StatusRecorder) *Watcher {
+	w := NewWithLeads(lead, final, r)
+	w.interval = testInterval
+	return w
+}
+
+// fakeClock is the watcher's wall clock under test. Reads come from the
+// evaluation goroutine while the test writes, so both go through the mutex.
+type fakeClock struct {
+	mu sync.Mutex
+	t  time.Time
+}
+
+func newFakeClock(t time.Time) *fakeClock {
+	return &fakeClock{t: t}
+}
+
+func (c *fakeClock) now() time.Time {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.t
+}
+
+// set jumps the clock, standing in for a resume from suspension or for an
+// NTP correction.
+func (c *fakeClock) set(t time.Time) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.t = t
+}
+
+// settle waits out a handful of evaluation ticks so a test can assert that
+// nothing was published.
+func settle() {
+	time.Sleep(20 * testInterval)
+}
+
+func TestUpdateZeroBeforeAnythingIsNoop(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	_ = w.Update(time.Time{})
+
+	if got := r.snapshot(); len(got) != 0 {
+		t.Fatalf("expected no events on initial zero, got %+v", got)
+	}
+}
+
+func TestUpdateNonZeroFiresStateChange(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(time.Hour)
+	_ = w.Update(d)
+
+	events := waitForEvents(t, r, 1)
+	if events[0].kind != stateChange {
+		t.Fatalf("expected stateChange, got %+v", events[0])
+	}
+	if !w.Deadline().Equal(d) {
+		t.Fatalf("deadline mismatch: %v vs %v", w.Deadline(), d)
+	}
+}
+
+func TestSameDeadlineIsNoop(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(time.Hour)
+	_ = w.Update(d)
+	_ = w.Update(d)
+	_ = w.Update(d)
+
+	events := waitForEvents(t, r, 1)
+	if len(events) != 1 {
+		t.Fatalf("expected exactly 1 event for repeated same deadline, got %d: %+v", len(events), events)
+	}
+}
+
+func TestWarningFiresOnceWithinLeadWindow(t *testing.T) {
+	r := &fakeRecorder{}
+	lead := 50 * time.Millisecond
+	w := newWatcher(lead, r)
+	defer w.Close()
+
+	// Deadline 80ms out — warning should fire after ~30ms.
+	d := time.Now().Add(80 * time.Millisecond)
+	_ = w.Update(d)
+
+	events := waitForEvents(t, r, 2)
+	if events[0].kind != stateChange {
+		t.Fatalf("event[0] should be stateChange, got %+v", events[0])
+	}
+	if !events[1].isWarning() {
+		t.Fatalf("event[1] should be a warning publish, got %+v", events[1])
+	}
+}
+
+func TestWarningFiresImmediatelyWhenAlreadyInsideWindow(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(time.Hour, r) // lead > delta => fire immediately
+	defer w.Close()
+
+	d := time.Now().Add(10 * time.Millisecond)
+	_ = w.Update(d)
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isWarning() {
+		t.Fatalf("expected immediate warning publish, got %+v", events[1])
+	}
+}
+
+func TestNewDeadlineCancelsPriorTimer(t *testing.T) {
+	r := &fakeRecorder{}
+	lead := 50 * time.Millisecond
+	w := newWatcher(lead, r)
+	defer w.Close()
+
+	first := time.Now().Add(80 * time.Millisecond) // would fire warning ~30ms in
+	_ = w.Update(first)
+
+	// Replace with a far-future deadline before the warning fires.
+	time.Sleep(5 * time.Millisecond)
+	second := time.Now().Add(time.Hour)
+	_ = w.Update(second)
+
+	// Wait past when first's warning would have fired.
+	time.Sleep(80 * time.Millisecond)
+
+	if n := countWhere(r.snapshot(), event.isWarning); n != 0 {
+		t.Fatalf("warning fired for cancelled deadline: %+v", r.snapshot())
+	}
+}
+
+func TestRefreshAfterFireArmsNewWarning(t *testing.T) {
+	r := &fakeRecorder{}
+	lead := 150 * time.Millisecond
+	w := newWatcher(lead, r)
+	defer w.Close()
+
+	// Warning fires ~20ms in; the deadline itself stays 150ms away so the
+	// replacement below lands well before it.
+	first := time.Now().Add(170 * time.Millisecond)
+	_ = w.Update(first)
+
+	// Wait for stateChange + warning of the first cycle.
+	waitForEvents(t, r, 2)
+
+	// Simulate a successful extend: brand new deadline.
+	second := time.Now().Add(60 * time.Millisecond)
+	_ = w.Update(second)
+
+	// 4 events total: stateChange, warning (first), stateChange, warning (second).
+	events := waitForEvents(t, r, 4)
+	if events[2].kind != stateChange {
+		t.Fatalf("event[2] should be stateChange for the new deadline, got %+v", events[2])
+	}
+	if !events[3].isWarning() {
+		t.Fatalf("event[3] should be a warning publish for the new deadline, got %+v", events[3])
+	}
+}
+
+func TestUpdateZeroAfterNonZeroClearsState(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(time.Hour, r)
+	defer w.Close()
+
+	d := time.Now().Add(2 * time.Hour)
+	_ = w.Update(d)
+	waitForEvents(t, r, 1)
+
+	_ = w.Update(time.Time{})
+
+	events := waitForEvents(t, r, 2)
+	if events[1].kind != stateChange {
+		t.Fatalf("expected stateChange on clear, got %+v", events[1])
+	}
+	if !w.Deadline().IsZero() {
+		t.Fatalf("Deadline should be zero after clear")
+	}
+}
+
+func TestUpdateRejectsBeforeEpoch(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	good := time.Now().Add(time.Hour)
+	if err := w.Update(good); err != nil {
+		t.Fatalf("seed Update: %v", err)
+	}
+
+	err := w.Update(time.Unix(-100, 0))
+	if !errors.Is(err, ErrDeadlineBeforeEpoch) {
+		t.Fatalf("want ErrDeadlineBeforeEpoch, got %v", err)
+	}
+	if !w.Deadline().IsZero() {
+		t.Fatalf("rejected pre-epoch update must clear deadline; got %v", w.Deadline())
+	}
+}
+
+func TestUpdateRejectsTooFarFuture(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	good := time.Now().Add(time.Hour)
+	if err := w.Update(good); err != nil {
+		t.Fatalf("seed Update: %v", err)
+	}
+
+	err := w.Update(time.Now().Add(50 * 365 * 24 * time.Hour))
+	if !errors.Is(err, ErrDeadlineTooFarFuture) {
+		t.Fatalf("want ErrDeadlineTooFarFuture, got %v", err)
+	}
+	if !w.Deadline().IsZero() {
+		t.Fatalf("rejected far-future update must clear deadline; got %v", w.Deadline())
+	}
+}
+
+func TestUpdateRecentPastRecordedAsExpired(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(-1 * time.Hour)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("recent-past Update should succeed, got %v", err)
+	}
+	if !w.Deadline().Equal(d) {
+		t.Fatalf("expected deadline to be recorded, got %v want %v", w.Deadline(), d)
+	}
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("recorder deadline = %v, want %v", got, d)
+	}
+
+	time.Sleep(80 * time.Millisecond)
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("no warning events may fire for an already-past deadline, got %+v", r.snapshot())
+	}
+}
+
+func TestUpdateAncientPastRejected(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	good := time.Now().Add(time.Hour)
+	if err := w.Update(good); err != nil {
+		t.Fatalf("seed Update: %v", err)
+	}
+	// Drain the stateChange from the seed.
+	waitForEvents(t, r, 1)
+
+	err := w.Update(time.Now().Add(-31 * 24 * time.Hour))
+	if !errors.Is(err, ErrDeadlineInPast) {
+		t.Fatalf("want ErrDeadlineInPast, got %v", err)
+	}
+	if !w.Deadline().IsZero() {
+		t.Fatalf("rejected ancient-past update must clear the deadline, got %v", w.Deadline())
+	}
+	events := waitForEvents(t, r, 2)
+	if events[1].kind != stateChange {
+		t.Fatalf("expected stateChange on clear, got %+v", events[1])
+	}
+}
+
+func TestCloseSilencesUpdates(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	w.Close()
+
+	if err := w.Update(time.Now().Add(time.Hour)); err != nil {
+		t.Fatalf("Update after Close: want nil, got %v", err)
+	}
+	if got := r.snapshot(); len(got) != 0 {
+		t.Fatalf("expected no events after Close, got %+v", got)
+	}
+}
+
+// TestCloseKeepsRecorderDeadline pins the reconnect-flap fix: the watcher
+// closes on every engine restart (network change, sleep/wake) while the
+// SSO deadline stays valid across those, so Close must leave the
+// server-scoped recorder's value in place. The client run loop clears the
+// recorder when it exits for real.
+func TestCloseKeepsRecorderDeadline(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(time.Hour, r)
+
+	d := time.Now().Add(2 * time.Hour)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("seed Update: %v", err)
+	}
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("recorder deadline after Update = %v, want %v", got, d)
+	}
+
+	w.Close()
+
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("recorder deadline after Close = %v, want %v", got, d)
+	}
+}
+
+// TestCloseWithoutDeadlineLeavesRecorderUntouched guards the symmetric
+// case: closing a watcher that never held a deadline must not emit a
+// redundant clear (the recorder may legitimately hold a value written by
+// some other path; the watcher only owns what it set).
+func TestCloseWithoutDeadlineLeavesRecorderUntouched(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(time.Hour, r)
+
+	w.Close()
+
+	if got := r.snapshot(); len(got) != 0 {
+		t.Fatalf("expected no events from Close on an empty watcher, got %+v", got)
+	}
+}
+
+func TestFinalWarningFiresAfterRegularWarning(t *testing.T) {
+	r := &fakeRecorder{}
+	// Warning fires at deadline-80ms, final at deadline-30ms.
+	w := newWatcherWithLeads(80*time.Millisecond, 30*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(100 * time.Millisecond)
+	_ = w.Update(d)
+
+	// Expect stateChange + warning + final-warning.
+	events := waitForEvents(t, r, 3)
+
+	if countWhere(events, func(e event) bool { return e.kind == stateChange }) != 1 {
+		t.Fatalf("expected exactly 1 stateChange, got %+v", events)
+	}
+	if countWhere(events, event.isWarning) != 1 {
+		t.Fatalf("expected exactly 1 warning publish, got %+v", events)
+	}
+	if countWhere(events, event.isFinalWarning) != 1 {
+		t.Fatalf("expected exactly 1 final-warning publish, got %+v", events)
+	}
+
+	// Warning must precede final (same deadline, longer lead fires first).
+	var wIdx, fIdx int
+	for i, e := range events {
+		switch {
+		case e.isWarning():
+			wIdx = i
+		case e.isFinalWarning():
+			fIdx = i
+		}
+	}
+	if wIdx > fIdx {
+		t.Fatalf("warning must publish before final-warning, got order %+v", events)
+	}
+}
+
+func TestDismissSuppressesFinalWarning(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(80*time.Millisecond, 30*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(100 * time.Millisecond)
+	_ = w.Update(d)
+
+	// Wait for the warning publish so we know we're inside the warning
+	// window, then dismiss before the final timer would fire.
+	deadline := time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		if countWhere(r.snapshot(), event.isWarning) >= 1 {
+			break
+		}
+		time.Sleep(2 * time.Millisecond)
+	}
+	if countWhere(r.snapshot(), event.isWarning) < 1 {
+		t.Fatalf("warning did not publish in time, events=%+v", r.snapshot())
+	}
+
+	w.Dismiss()
+
+	// Now wait past when the final would have fired.
+	time.Sleep(120 * time.Millisecond)
+
+	if n := countWhere(r.snapshot(), event.isFinalWarning); n != 0 {
+		t.Fatalf("final-warning published after Dismiss(), events=%+v", r.snapshot())
+	}
+}
+
+func TestDismissResetByNewDeadline(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(80*time.Millisecond, 30*time.Millisecond, r)
+	defer w.Close()
+
+	first := time.Now().Add(100 * time.Millisecond)
+	_ = w.Update(first)
+
+	// Dismiss against the first deadline.
+	w.Dismiss()
+
+	// Replace with a fresh deadline before the first's timers complete.
+	time.Sleep(10 * time.Millisecond)
+	second := time.Now().Add(100 * time.Millisecond)
+	_ = w.Update(second)
+
+	// The second cycle must publish a final-warning (the dismiss state
+	// did not carry over).
+	deadline := time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		if countWhere(r.snapshot(), event.isFinalWarning) >= 1 {
+			break
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	if countWhere(r.snapshot(), event.isFinalWarning) < 1 {
+		t.Fatalf("final-warning did not publish on fresh deadline after Dismiss reset, events=%+v", r.snapshot())
+	}
+}
+
+func TestDismissBeforeUpdateIsNoop(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(80*time.Millisecond, 30*time.Millisecond, r)
+	defer w.Close()
+
+	// No deadline tracked yet; Dismiss must be a no-op (no panic, no state).
+	w.Dismiss()
+
+	d := time.Now().Add(100 * time.Millisecond)
+	_ = w.Update(d)
+
+	// Final warning should still publish — Dismiss only acts on the current
+	// deadline, and there was none at the time of the call.
+	deadline := time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		if countWhere(r.snapshot(), event.isFinalWarning) >= 1 {
+			return
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	t.Fatalf("final-warning did not publish after no-op pre-Update Dismiss, events=%+v", r.snapshot())
+}
+
+// The tests below drive the watcher's wall clock directly. The deadline sits
+// an hour out in real time and the fake clock jumps, standing in for a device
+// that was suspended and resumed somewhere inside — or past — the warning
+// windows. The evaluation loop is what reacts to the jump, so these exercise
+// the same path production takes on a resume.
+func newResumeWatcher(t *testing.T, r *fakeRecorder) (*Watcher, *fakeClock, time.Time) {
+	t.Helper()
+
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	start := time.Now()
+	clock := newFakeClock(start)
+	// Set before Update: the evaluation loop does not exist yet.
+	w.nowFn = clock.now
+	t.Cleanup(w.Close)
+
+	deadline := start.Add(time.Hour).Round(0)
+	if err := w.Update(deadline); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+	return w, clock, deadline
+}
+
+func TestResumeInsideWarningWindowWarns(t *testing.T) {
+	r := &fakeRecorder{}
+	_, clock, deadline := newResumeWatcher(t, r)
+
+	clock.set(deadline.Add(-5 * time.Minute))
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isWarning() {
+		t.Fatalf("expected the interactive warning after the resume, got %+v", events[1])
+	}
+	if n := countWhere(events, event.isFinalWarning); n != 0 {
+		t.Fatalf("final-warning must wait for its own window, got %d: %+v", n, events)
+	}
+}
+
+func TestResumeInsideFinalWindowSendsFinalWarningOnly(t *testing.T) {
+	r := &fakeRecorder{}
+	_, clock, deadline := newResumeWatcher(t, r)
+
+	clock.set(deadline.Add(-time.Minute))
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isFinalWarning() {
+		t.Fatalf("expected the final warning after the resume, got %+v", events[1])
+	}
+	settle()
+	if n := countWhere(r.snapshot(), event.isWarning); n != 0 {
+		t.Fatalf("the interactive warning is stale inside the final window, got %d: %+v", n, r.snapshot())
+	}
+}
+
+func TestResumePastDeadlinePublishesNothing(t *testing.T) {
+	r := &fakeRecorder{}
+	_, clock, deadline := newResumeWatcher(t, r)
+
+	clock.set(deadline.Add(time.Minute))
+
+	settle()
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("an expired session must not warn, got %d publishes: %+v", n, r.snapshot())
+	}
+}
+
+func TestWarningPublishesOncePerDeadline(t *testing.T) {
+	r := &fakeRecorder{}
+	_, clock, deadline := newResumeWatcher(t, r)
+
+	clock.set(deadline.Add(-5 * time.Minute))
+	waitForEvents(t, r, 2)
+
+	// Many ticks pass inside the same window.
+	settle()
+	if n := countWhere(r.snapshot(), event.isWarning); n != 1 {
+		t.Fatalf("expected exactly 1 warning publish across ticks, got %d: %+v", n, r.snapshot())
+	}
+}
+
+// TestWarningRecoversFromAClockRunningAhead covers the device that boots
+// before NTP has corrected it: the deadline looks long gone, nothing is
+// published, and the warning still arrives once the clock is fixed.
+func TestWarningRecoversFromAClockRunningAhead(t *testing.T) {
+	r := &fakeRecorder{}
+	_, clock, deadline := newResumeWatcher(t, r)
+
+	clock.set(deadline.Add(2 * time.Hour))
+	settle()
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("a deadline that looks expired must not warn, got %d publishes: %+v", n, r.snapshot())
+	}
+
+	clock.set(deadline.Add(-5 * time.Minute))
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isWarning() {
+		t.Fatalf("expected the warning once the clock was corrected, got %+v", events[1])
+	}
+}
+
+func TestResumeInsideFinalWindowRespectsDismiss(t *testing.T) {
+	r := &fakeRecorder{}
+	w, clock, deadline := newResumeWatcher(t, r)
+
+	// The user dismissed the warning for this deadline before the device
+	// was suspended; resuming inside the final window must not reopen it.
+	w.Dismiss()
+	clock.set(deadline.Add(-time.Minute))
+
+	settle()
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("a dismissed deadline must not warn on resume, got %d: %+v", n, r.snapshot())
+	}
+}
+
+func TestCloseStopsTheEvaluationLoop(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	start := time.Now()
+	clock := newFakeClock(start)
+	w.nowFn = clock.now
+
+	deadline := start.Add(time.Hour).Round(0)
+	if err := w.Update(deadline); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+	w.Close()
+
+	clock.set(deadline.Add(-5 * time.Minute))
+	settle()
+
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("a closed watcher must not publish, got %d: %+v", n, r.snapshot())
+	}
+}
+
+func TestDeadlineOnlyRecordsDeadlineWithoutWarnings(t *testing.T) {
+	r := &fakeRecorder{}
+	w := NewDeadlineOnly(r)
+	defer w.Close()
+
+	// With the default leads this deadline sits inside the final-warning
+	// window, so a watcher that warns at all would publish on the spot.
+	d := time.Now().Add(50 * time.Millisecond).Round(0)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("expected recorder deadline %v, got %v", d, got)
+	}
+
+	time.Sleep(100 * time.Millisecond)
+
+	events := r.snapshot()
+	if got := countWhere(events, func(e event) bool { return e.kind == publish }); got != 0 {
+		t.Fatalf("expected no publish in deadline-only mode, got %d: %+v", got, events)
+	}
+	w.mu.Lock()
+	polling := w.stop != nil
+	w.mu.Unlock()
+	if polling {
+		t.Fatal("expected no evaluation loop in deadline-only mode")
+	}
+}
+
+func TestDeadlineOnlyStillRejectsOutOfRangeDeadlines(t *testing.T) {
+	r := &fakeRecorder{}
+	w := NewDeadlineOnly(r)
+	defer w.Close()
+
+	if err := w.Update(time.Now().Add(time.Hour)); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	err := w.Update(time.Now().Add(-maxPastHorizon - time.Hour))
+	if !errors.Is(err, ErrDeadlineInPast) {
+		t.Fatalf("expected ErrDeadlineInPast, got %v", err)
+	}
+	if got := r.deadline(); !got.IsZero() {
+		t.Fatalf("expected recorder cleared after rejection, got %v", got)
+	}
+}
+
+// TestClockAheadAtUpdateStillWarnsOnceCorrected covers a client that connects
+// while its clock runs ahead of real time: the deadline reads as already
+// expired when it arrives, so nothing publishes, and the warning must still
+// come once NTP pulls the clock back.
+func TestClockAheadAtUpdateStillWarnsOnceCorrected(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	deadline := time.Now().Add(time.Hour).Round(0)
+	// Two hours past the deadline from the device's point of view, well
+	// inside maxPastHorizon, so Update accepts and records it.
+	clock := newFakeClock(deadline.Add(2 * time.Hour))
+	w.nowFn = clock.now
+	t.Cleanup(w.Close)
+
+	if err := w.Update(deadline); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	settle()
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("a deadline that reads as expired must not warn, got %d: %+v", n, r.snapshot())
+	}
+
+	clock.set(deadline.Add(-5 * time.Minute))
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isWarning() {
+		t.Fatalf("expected the warning once the clock was corrected, got %+v", events[1])
+	}
+}
+
+// TestWarningNeverPrecedesTheDeadlineStateChange pins the ordering Update
+// documents: consumers learn the new deadline before they see a warning that
+// refers to it. The deadline here already sits inside the warning window, and
+// the recorder stalls, so the evaluation loop gets many chances to publish
+// while Update is still announcing.
+func TestWarningNeverPrecedesTheDeadlineStateChange(t *testing.T) {
+	r := &fakeRecorder{setDelay: 50 * time.Millisecond}
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	deadline := time.Now().Add(time.Hour).Round(0)
+	clock := newFakeClock(deadline.Add(-5 * time.Minute))
+	w.nowFn = clock.now
+	t.Cleanup(w.Close)
+
+	if err := w.Update(deadline); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	events := waitForEvents(t, r, 2)
+	if events[0].kind != stateChange {
+		t.Fatalf("event[0] should be the deadline state change, got %+v", events)
+	}
+	if !events[1].isWarning() {
+		t.Fatalf("event[1] should be the warning, got %+v", events)
+	}
+}
+
+// TestUpdateWakesTheLoopWithoutWaitingForATick pins the hand-off: Update
+// publishes nothing itself, it nudges the evaluation loop, so a deadline that
+// already sits inside a warning window is warned about at once even though the
+// ticker here would not fire for an hour.
+func TestUpdateWakesTheLoopWithoutWaitingForATick(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	w.interval = time.Hour
+	t.Cleanup(w.Close)
+
+	d := time.Now().Add(5 * time.Minute).Round(0)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	events := waitForEvents(t, r, 2)
+	if !events[1].isWarning() {
+		t.Fatalf("expected the warning on the wake-up, got %+v", events[1])
+	}
+}
+
+// blockingRecorder holds a publish open until the test releases it, so the
+// evaluation loop can be parked mid-publish while Close is called.
+type blockingRecorder struct {
+	fakeRecorder
+	entered chan struct{}
+	release chan struct{}
+}
+
+func (r *blockingRecorder) PublishEvent(
+	severity cProto.SystemEvent_Severity,
+	category cProto.SystemEvent_Category,
+	message string,
+	userMessage string,
+	metadata map[string]string,
+) {
+	select {
+	case r.entered <- struct{}{}:
+	default:
+	}
+	<-r.release
+	r.fakeRecorder.PublishEvent(severity, category, message, userMessage, metadata)
+}
+
+// TestConcurrentCloseWaitsForTheLoop pins the contract for the caller that
+// loses the race: Close returns only once the loop is done, whichever of the
+// two calls got there first.
+func TestConcurrentCloseWaitsForTheLoop(t *testing.T) {
+	r := &blockingRecorder{entered: make(chan struct{}, 1), release: make(chan struct{})}
+	var releaseOnce sync.Once
+	release := func() { releaseOnce.Do(func() { close(r.release) }) }
+
+	w := newWatcherWithLeads(WarningLead, FinalWarningLead, r)
+	w.interval = time.Hour
+	// Order matters: Close waits for the loop, which stays parked in the
+	// publish until the release, so a t.Fatal below would hang the cleanup
+	// instead of reporting the failure.
+	t.Cleanup(func() {
+		release()
+		w.Close()
+	})
+
+	d := time.Now().Add(5 * time.Minute).Round(0)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	// The loop is now parked inside the warning publish.
+	select {
+	case <-r.entered:
+	case <-time.After(2 * time.Second):
+		t.Fatal("the loop never reached the publish")
+	}
+
+	first := make(chan struct{})
+	second := make(chan struct{})
+	go func() { w.Close(); close(first) }()
+	go func() { w.Close(); close(second) }()
+
+	select {
+	case <-first:
+		t.Fatal("Close returned while the loop was still publishing")
+	case <-second:
+		t.Fatal("Close returned while the loop was still publishing")
+	case <-time.After(100 * time.Millisecond):
+	}
+
+	release()
+	for _, done := range []chan struct{}{first, second} {
+		select {
+		case <-done:
+		case <-time.After(2 * time.Second):
+			t.Fatal("Close did not return after the publish completed")
+		}
+	}
+}

client/internal/auth/util.go

@@ -20,14 +20,26 @@ func randomBytesInHex(count int) (string, error) {
 	return hex.EncodeToString(buf), nil
 }
 
-// isValidAccessToken is a simple validation of the access token
-func isValidAccessToken(token string, audience string) error {
+// validateTokenAudience checks that the token is a well-formed JWT whose
+// audience claim matches the expected audience.
+//
+// It does NOT verify the token's cryptographic signature and therefore must not
+// be treated as an authenticity check. The token is obtained by the client
+// directly from the IdP token endpoint over TLS, and its signature is verified
+// server-side by the management server against the IdP's JWKS
+// (see shared/auth/jwt/validator.go). This function is only a client-side
+// sanity check that the returned token targets the expected audience.
+func validateTokenAudience(token string, audience string) error {
 	if token == "" {
 		return fmt.Errorf("token received is empty")
 	}
 
-	encodedClaims := strings.Split(token, ".")[1]
-	claimsString, err := base64.RawURLEncoding.DecodeString(encodedClaims)
+	parts := strings.Split(token, ".")
+	if len(parts) != 3 {
+		return fmt.Errorf("token is not a well-formed JWT")
+	}
+
+	claimsString, err := base64.RawURLEncoding.DecodeString(parts[1])
 	if err != nil {
 		return err
 	}

client/internal/auth/util_test.go

@@ -0,0 +1,108 @@
+package auth
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+)
+
+// makeJWT builds an unsigned JWT-shaped string (header.payload.signature) with
+// the given claims payload. The signature part is arbitrary because
+// validateTokenAudience intentionally does not verify it.
+func makeJWT(t *testing.T, claims map[string]interface{}) string {
+	t.Helper()
+	header := base64.RawURLEncoding.EncodeToString([]byte(`{"alg":"RS256","typ":"JWT"}`))
+	payloadBytes, err := json.Marshal(claims)
+	if err != nil {
+		t.Fatalf("marshal claims: %v", err)
+	}
+	payload := base64.RawURLEncoding.EncodeToString(payloadBytes)
+	return header + "." + payload + ".unverified-signature"
+}
+
+func TestValidateTokenAudience(t *testing.T) {
+	tests := []struct {
+		name     string
+		token    string
+		audience string
+		wantErr  bool
+	}{
+		{
+			name:     "empty token",
+			token:    "",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "not a JWT - no dots",
+			token:    "notajwt",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "not a JWT - two parts only",
+			token:    "header.payload",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "matching string audience",
+			token:    makeJWT(t, map[string]interface{}{"aud": "netbird"}),
+			audience: "netbird",
+			wantErr:  false,
+		},
+		{
+			name:     "mismatching string audience",
+			token:    makeJWT(t, map[string]interface{}{"aud": "other"}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "matching audience in array",
+			token:    makeJWT(t, map[string]interface{}{"aud": []interface{}{"other", "netbird"}}),
+			audience: "netbird",
+			wantErr:  false,
+		},
+		{
+			name:     "mismatching audience array",
+			token:    makeJWT(t, map[string]interface{}{"aud": []interface{}{"a", "b"}}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "missing audience claim",
+			token:    makeJWT(t, map[string]interface{}{"sub": "user"}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "invalid base64 payload",
+			token:    "header.!!!not-base64!!!.sig",
+			audience: "netbird",
+			wantErr:  true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := validateTokenAudience(tc.token, tc.audience)
+			if tc.wantErr && err == nil {
+				t.Fatalf("expected error, got nil")
+			}
+			if !tc.wantErr && err != nil {
+				t.Fatalf("expected no error, got %v", err)
+			}
+		})
+	}
+}
+
+// TestValidateTokenAudienceNoPanic guards the regression where a non-empty
+// token without the JWT dot structure caused an index-out-of-range panic.
+func TestValidateTokenAudienceNoPanic(t *testing.T) {
+	inputs := []string{"a", ".", "a.", "aaaa", "no-dots-here"}
+	for _, in := range inputs {
+		if err := validateTokenAudience(in, "netbird"); err == nil {
+			t.Fatalf("expected error for malformed token %q, got nil", in)
+		}
+	}
+}

client/internal/certproof/collect.go

@@ -0,0 +1,168 @@
+package certproof
+
+import (
+	"context"
+	"crypto"
+	"crypto/sha256"
+	"crypto/x509"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// Collect answers the certificate challenges in checks: for each challenge it picks a
+// stored certificate that chains to the challenge's CAs and signs the nonce with its
+// key. The same certificate is proven once even if several checks accept it.
+func Collect(ctx context.Context, store Store, checks []*proto.Checks, peerKey []byte) []certposture.Proof {
+	challenges := certificateChallenges(checks)
+	if len(challenges) == 0 {
+		logNoChallenges(checks)
+		return nil
+	}
+	return CollectChallenges(ctx, store, challenges, peerKey)
+}
+
+func logNoChallenges(checks []*proto.Checks) {
+	if len(checks) > 0 {
+		log.Debugf("certificate posture: %d posture checks received, none carries a certificate challenge", len(checks))
+	}
+}
+
+// CollectChallenges answers challenges already extracted from the posture checks, so a
+// caller that ships them across a process boundary reuses the same matching and signing.
+// Only nonces of the size management issues are signed, for a peer key of the size of
+// ours, so the keys behind the store never sign arbitrary caller-chosen data.
+func CollectChallenges(ctx context.Context, store Store, challenges []*proto.CertificateChallenge, peerKey []byte) []certposture.Proof {
+	if len(peerKey) != wgtypes.KeyLen {
+		log.Warnf("certificate posture: refusing to sign for a %d byte peer key", len(peerKey))
+		return nil
+	}
+	challenges = wellFormed(challenges)
+	if len(challenges) == 0 {
+		return nil
+	}
+	log.Debugf("certificate posture: answering %d certificate challenges from store %T", len(challenges), store)
+
+	candidates, err := store.Candidates(ctx)
+	if err != nil {
+		log.Warnf("failed loading certificates for posture checks: %v", err)
+		return nil
+	}
+	if len(candidates) == 0 {
+		log.Debug("certificate posture: certificate store holds no candidates, no proof will be sent")
+		return nil
+	}
+	log.Debugf("certificate posture: store holds %d candidate certificates", len(candidates))
+
+	now := time.Now()
+	proven := make(map[[sha256.Size]byte]struct{})
+	var proofs []certposture.Proof
+	for i, challenge := range challenges {
+		roots, err := certposture.ParseCAs(challenge.GetCaCertificates())
+		if err != nil {
+			log.Warnf("skipping certificate challenge with invalid CA certificates: %v", err)
+			continue
+		}
+		log.Debugf("certificate posture: challenge %d accepts %d CA certificates, nonce is %d bytes", i, len(challenge.GetCaCertificates()), len(challenge.GetNonce()))
+
+		matched := false
+		for _, candidate := range candidates {
+			if len(candidate.Chain) == 0 {
+				continue
+			}
+			leaf := candidate.Chain[0]
+			chain, err := certposture.VerifiedChain(leaf, candidate.issuers(), roots, now)
+			if err != nil {
+				log.Debugf("certificate posture: challenge %d rejected %q issued by %q: %v", i, leaf.Subject, leaf.Issuer, err)
+				continue
+			}
+			matched = true
+
+			// The same leaf can chain to different CAs for different challenges, and
+			// management checks each chain against each check's CAs, so a proof is
+			// deduplicated by its whole chain rather than by its leaf.
+			fingerprint := chainFingerprint(chain)
+			if _, done := proven[fingerprint]; done {
+				log.Debugf("certificate posture: challenge %d matched %q, already proven for an earlier challenge", i, leaf.Subject)
+				break
+			}
+			proof, err := prove(candidate.Signer, chain, challenge.GetNonce(), peerKey)
+			if err != nil {
+				log.Warnf("failed signing certificate proof for %s: %v", leaf.Subject, err)
+				continue
+			}
+			log.Debugf("certificate posture: challenge %d proven by %q with %s, signature %d bytes, chain of %d", i, leaf.Subject, proof.SigAlg, len(proof.Signature), len(proof.Chain))
+			proven[fingerprint] = struct{}{}
+			proofs = append(proofs, proof)
+			break
+		}
+		if !matched {
+			log.Debugf("certificate posture: challenge %d matched none of the %d candidates", i, len(candidates))
+		}
+	}
+	log.Debugf("certificate posture: %d challenges produced %d proofs", len(challenges), len(proofs))
+	return proofs
+}
+
+// HasChallenges reports whether any of checks asks for a certificate proof.
+func HasChallenges(checks []*proto.Checks) bool {
+	return len(certificateChallenges(checks)) > 0
+}
+
+func certificateChallenges(checks []*proto.Checks) []*proto.CertificateChallenge {
+	var challenges []*proto.CertificateChallenge
+	for _, check := range checks {
+		if challenge := check.GetCertificateChallenge(); challenge != nil {
+			challenges = append(challenges, challenge)
+		}
+	}
+	return wellFormed(challenges)
+}
+
+// wellFormed drops challenges whose nonce is not one management could have issued.
+func wellFormed(challenges []*proto.CertificateChallenge) []*proto.CertificateChallenge {
+	var kept []*proto.CertificateChallenge
+	for _, challenge := range challenges {
+		if len(challenge.GetNonce()) != certposture.NonceSize {
+			log.Debugf("certificate posture: skipping challenge with a %d byte nonce", len(challenge.GetNonce()))
+			continue
+		}
+		kept = append(kept, challenge)
+	}
+	return kept
+}
+
+func prove(signer crypto.Signer, chain []*x509.Certificate, nonce, peerKey []byte) (certposture.Proof, error) {
+	sigAlg, sig, err := certposture.Sign(signer, nonce, peerKey)
+	if err != nil {
+		return certposture.Proof{}, err
+	}
+	der := make([][]byte, 0, len(chain))
+	for _, cert := range chain {
+		der = append(der, cert.Raw)
+	}
+	return certposture.Proof{Nonce: nonce, Chain: der, SigAlg: sigAlg, Signature: sig}, nil
+}
+
+func chainFingerprint(chain []*x509.Certificate) [sha256.Size]byte {
+	ders := make([][]byte, 0, len(chain))
+	for _, cert := range chain {
+		ders = append(ders, cert.Raw)
+	}
+	return chainDERFingerprint(ders)
+}
+
+// chainDERFingerprint identifies a chain of DER certificates by the hashes of all of them,
+// in order.
+func chainDERFingerprint(chain [][]byte) [sha256.Size]byte {
+	buf := make([]byte, 0, len(chain)*sha256.Size)
+	for _, der := range chain {
+		certHash := sha256.Sum256(der)
+		buf = append(buf, certHash[:]...)
+	}
+	return sha256.Sum256(buf)
+}

client/internal/certproof/collect_darwin.go

@@ -0,0 +1,137 @@
+//go:build !ios
+
+package certproof
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+const helperTimeout = 30 * time.Second
+
+// userHelperBackoff holds off asking a user's keychain again after it proved nothing.
+var userHelperBackoff = newHelperBackoff()
+
+// CollectProofs answers the certificate challenges in checks from every store this Mac
+// can reach. The root daemon reads the System keychain itself, which is where MDM
+// installs device identities, and reaches the console user's login keychain only by
+// launching a helper into that user's session. A Mac sitting at the login window
+// therefore yields device proofs alone.
+func CollectProofs(ctx context.Context, checks []*proto.Checks, peerKey []byte, cfg Config) []certposture.Proof {
+	challenges := certificateChallenges(checks)
+	if len(challenges) == 0 {
+		logNoChallenges(checks)
+		return nil
+	}
+
+	// A helper already runs inside the user's session, so it reads its own keychain
+	// directly and must never launch another one.
+	if os.Geteuid() != 0 {
+		return CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
+	}
+
+	proofs := CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
+	if cfg.OwnerUnknown {
+		return proofs
+	}
+
+	userProofs, err := collectAsConsoleUser(ctx, cfg.ProfileOwner, challenges, peerKey)
+	if err != nil {
+		log.Debugf("certificate posture: console user keychain unavailable: %v", err)
+	}
+	return mergeProofs(proofs, userProofs)
+}
+
+// UserContext identifies the user whose keychain a collection would include: the console
+// user when it owns the active profile, or empty when no user keychain would be asked. A
+// change means a collection made earlier no longer reflects what this Mac can prove.
+func UserContext(cfg Config) string {
+	if os.Geteuid() != 0 || cfg.OwnerUnknown {
+		return ""
+	}
+	user, ok := currentConsoleUser()
+	if !ok || !user.isOwner(cfg.ProfileOwner) {
+		return ""
+	}
+	return strconv.FormatUint(uint64(user.UID), 10) + ":" + user.Name
+}
+
+// collectAsConsoleUser runs the helper inside the desktop session of the logged-in
+// user. Dropping to their uid is not enough: keychain access is an XPC call to a
+// per-session securityd, so the helper has to enter their Mach bootstrap namespace,
+// which is what launchctl asuser does.
+func collectAsConsoleUser(ctx context.Context, owner string, challenges []*proto.CertificateChallenge, peerKey []byte) ([]certposture.Proof, error) {
+	user, ok := currentConsoleUser()
+	if !ok {
+		return nil, nil
+	}
+	if !user.isOwner(owner) {
+		log.Debugf("certificate posture: console user %s does not own the active profile, no user keychain is asked", user.Name)
+		return nil, nil
+	}
+
+	uid := strconv.FormatUint(uint64(user.UID), 10)
+	backoffKey := helperBackoffKey(uid, challenges)
+	if !userHelperBackoff.allow(backoffKey, time.Now()) {
+		log.Debugf("certificate posture: the keychain of uid %s proved nothing recently, not asking again yet", uid)
+		return nil, nil
+	}
+
+	binary, err := os.Executable()
+	if err != nil {
+		return nil, fmt.Errorf("resolve own binary: %w", err)
+	}
+
+	parent := ctx
+	ctx, cancel := context.WithTimeout(ctx, helperTimeout)
+	defer cancel()
+
+	// Absolute paths, because the daemon's PATH is configurable through the service
+	// environment, and sudo selects the user by uid so the name never has to round-trip.
+	cmd := exec.CommandContext(ctx, "/bin/launchctl", "asuser", uid, "/usr/bin/sudo", "-u", "#"+uid, "-H", "--", binary, "posture", "cert-proof")
+	killHelperGroupOnCancel(cmd)
+
+	log.Debugf("certificate posture: asking the desktop session of uid %s to answer %d challenges", uid, len(challenges))
+	proofs, err := runHelperCmd(cmd, helperRequest(challenges, peerKey))
+	// A run that completed, or ran into the timeout waiting on a prompt nobody answered,
+	// tells whether the keychain proves anything. A launch or output failure, or a run the
+	// caller cut short, says nothing about it and must not hold off the next one.
+	timedOut := errors.Is(ctx.Err(), context.DeadlineExceeded) && parent.Err() == nil
+	if err == nil || timedOut {
+		userHelperBackoff.record(backoffKey, err == nil && len(proofs) > 0, time.Now())
+	}
+	if err != nil {
+		return nil, fmt.Errorf("run helper as uid %s: %w", uid, err)
+	}
+	log.Debugf("certificate posture: desktop session of uid %s returned %d proofs", uid, len(proofs))
+	return proofs, nil
+}
+
+// helperStore is the store the helper reads: the user's login keychain alone. The
+// session's search list also holds the System keychain, which the daemon reads itself,
+// and using a System keychain key from the user's session would ask for an
+// administrator's approval.
+func helperStore() Store {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		log.Debugf("certificate posture: no home directory, searching the default keychain list: %v", err)
+		return newKeychainStore()
+	}
+	login := filepath.Join(home, "Library", "Keychains", "login.keychain-db")
+	if _, err := os.Stat(login); err != nil {
+		// Keychains created before macOS 10.12 keep the old file name.
+		login = filepath.Join(home, "Library", "Keychains", "login.keychain")
+	}
+	return newKeychainStore(login)
+}

client/internal/certproof/collect_js.go

@@ -0,0 +1,31 @@
+//go:build js
+
+package certproof
+
+import (
+	"context"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// CollectProofs proves nothing in a browser: it has no TPM, certificate store or file
+// store to sign with, so the stores stay out of the WebAssembly build.
+func CollectProofs(context.Context, []*proto.Checks, []byte, Config) []certposture.Proof {
+	return nil
+}
+
+// UserContext identifies the user whose certificates a collection would include. A
+// browser has no per-user store, so it never changes.
+func UserContext(Config) string {
+	return ""
+}
+
+// DefaultStore is empty in a browser.
+func DefaultStore() Store {
+	return Stores{}
+}
+
+func helperStore() Store {
+	return DefaultStore()
+}

client/internal/certproof/collect_other.go

@@ -0,0 +1,31 @@
+//go:build ((!darwin && !windows) || ios) && !js
+
+package certproof
+
+import (
+	"context"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// CollectProofs answers the certificate challenges in checks from the PEM directory cfg
+// names, joined by its PKCS#11 token when it names one. Only macOS and Windows keep
+// per-user certificates out of reach of a privileged daemon, so every other platform
+// reads its store in the daemon itself.
+func CollectProofs(ctx context.Context, checks []*proto.Checks, peerKey []byte, cfg Config) []certposture.Proof {
+	return Collect(ctx, storeWithToken(cfg), checks, peerKey)
+}
+
+// UserContext identifies the user whose certificates a collection would include. These
+// platforms have no per-user store, so it never changes.
+func UserContext(Config) string {
+	return ""
+}
+
+// helperStore is the store the helper reads. Nothing launches a helper on these
+// platforms, so it is the store the daemon reads, configured from the same environment,
+// which lets an administrator check a setup by running the helper by hand.
+func helperStore() Store {
+	return storeWithToken(Config{PKCS11: PKCS11FromEnv()})
+}

client/internal/certproof/collect_test.go

@@ -0,0 +1,258 @@
+package certproof
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/x509"
+	"math/big"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+var peerKey = []byte("peer-public-key-aaaaaaaaaaaaaaaa")
+
+func TestCollect_ProvesOneMatchingCertificatePerChallenge(t *testing.T) {
+	corpCA := certtest.NewCA(t, "corp-root")
+	otherCA := certtest.NewCA(t, "other-root")
+	unrelatedCA := certtest.NewCA(t, "unrelated-root")
+
+	dir := storeDir(t)
+	deviceKey := certtest.ECDSAKey(t)
+	device := corpCA.Issue(t, deviceKey, "device")
+	writeFile(t, dir, "device.pem", certtest.CertPEM(device)+certtest.KeyPEM(t, deviceKey))
+
+	otherKey := certtest.RSAKey(t)
+	writeFile(t, dir, "other.crt", certtest.CertPEM(otherCA.Issue(t, otherKey, "other")))
+	writeFile(t, dir, "other.key", certtest.KeyPEM(t, otherKey))
+
+	writeFile(t, dir, "keyless.crt", certtest.CertPEM(corpCA.Issue(t, certtest.ECDSAKey(t), "keyless")))
+	writeFile(t, dir, "notes.txt", "ignored")
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	nonce := challenger.Nonce(peerKey, time.Now())
+	challenge := func(cas ...string) *proto.Checks {
+		return &proto.Checks{CertificateChallenge: &proto.CertificateChallenge{Nonce: nonce, CaCertificates: cas}}
+	}
+	checks := []*proto.Checks{
+		{Files: []string{"/usr/bin/agent"}},
+		challenge(corpCA.PEM),
+		challenge(corpCA.PEM),
+		challenge(otherCA.PEM),
+		challenge(unrelatedCA.PEM),
+		challenge("not a pem"),
+	}
+
+	proofs := Collect(context.Background(), newFileStore(dir), checks, peerKey)
+
+	require.Len(t, proofs, 2)
+	var subjects []string
+	for _, p := range proofs {
+		chain, err := challenger.Verify(p, peerKey, time.Now())
+		require.NoError(t, err)
+		subjects = append(subjects, chain[0].Subject.CommonName)
+	}
+	assert.ElementsMatch(t, []string{"device", "other"}, subjects)
+}
+
+func TestCollect_NothingToProve(t *testing.T) {
+	dir := storeDir(t)
+	key := certtest.ECDSAKey(t)
+	ca := certtest.NewCA(t, "root")
+	writeFile(t, dir, "device.pem", certtest.CertPEM(ca.Issue(t, key, "device"))+certtest.KeyPEM(t, key))
+
+	tests := []struct {
+		name   string
+		store  Store
+		checks []*proto.Checks
+	}{
+		{"no checks", newFileStore(dir), nil},
+		{"files only", newFileStore(dir), []*proto.Checks{{Files: []string{"/bin/x"}}}},
+		{"challenge without nonce", newFileStore(dir), []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{CaCertificates: []string{ca.PEM}}}}},
+		{"missing store dir", newFileStore(filepath.Join(dir, "missing")), []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{Nonce: make([]byte, certposture.NonceSize), CaCertificates: []string{ca.PEM}}}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Nil(t, Collect(context.Background(), tt.store, tt.checks, peerKey))
+		})
+	}
+}
+
+func TestFileStore_ChainWithIntermediate(t *testing.T) {
+	root := certtest.NewCA(t, "root")
+	intermediate := certtest.NewIntermediate(t, root, "intermediate")
+	key := certtest.ECDSAKey(t)
+	leaf := intermediate.Issue(t, key, "device")
+
+	dir := storeDir(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(leaf)+certtest.CertPEM(intermediate.Cert)+certtest.KeyPEM(t, key))
+
+	candidates, err := newFileStore(dir).Candidates(context.Background())
+	require.NoError(t, err)
+	require.Len(t, candidates, 1)
+	require.Len(t, candidates[0].Chain, 2)
+
+	roots, err := certposture.ParseCAs([]string{root.PEM})
+	require.NoError(t, err)
+	assert.NoError(t, certposture.VerifyChain(candidates[0].Chain, roots, time.Now()))
+}
+
+// storeDir is a PEM directory the store accepts: t.TempDir follows the umask, which
+// leaves the directory group-writable on systems with a user-private group umask.
+func storeDir(t *testing.T) string {
+	t.Helper()
+	dir := t.TempDir()
+	require.NoError(t, os.Chmod(dir, 0o700))
+	return dir
+}
+
+func writeFile(t *testing.T, dir, name, content string) {
+	t.Helper()
+	require.NoError(t, os.WriteFile(filepath.Join(dir, name), []byte(content), 0o600))
+}
+
+func TestCollectChallenges_RefusesMalformedInput(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	dir := storeDir(t)
+	key := certtest.ECDSAKey(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(ca.Issue(t, key, "device"))+certtest.KeyPEM(t, key))
+	store := newFileStore(dir)
+	nonce := certposture.NewChallenger([]byte("secret")).Nonce(peerKey, time.Now())
+
+	tests := []struct {
+		name    string
+		nonce   []byte
+		peerKey []byte
+		want    int
+	}{
+		{"issued nonce and peer key are signed", nonce, peerKey, 1},
+		{"short nonce is not signed", nonce[:8], peerKey, 0},
+		{"oversized nonce is not signed", append(append([]byte{}, nonce...), 0), peerKey, 0},
+		{"short peer key is not signed", nonce, peerKey[:16], 0},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			challenges := []*proto.CertificateChallenge{{Nonce: tt.nonce, CaCertificates: []string{ca.PEM}}}
+			assert.Len(t, CollectChallenges(context.Background(), store, challenges, tt.peerKey), tt.want,
+				"the device key signs only what management could have issued")
+		})
+	}
+}
+
+func TestFileStore_SkipsKeyOfAnotherCertificate(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	dir := storeDir(t)
+
+	// A stale key next to a renewed certificate, sorted before the good pair, must not
+	// produce a proof that management rejects and stop the search there.
+	writeFile(t, dir, "a-renewed.crt", certtest.CertPEM(ca.Issue(t, certtest.ECDSAKey(t), "renewed")))
+	writeFile(t, dir, "a-renewed.key", certtest.KeyPEM(t, certtest.ECDSAKey(t)))
+	goodKey := certtest.ECDSAKey(t)
+	good := ca.Issue(t, goodKey, "good")
+	writeFile(t, dir, "b-good.pem", certtest.CertPEM(good)+certtest.KeyPEM(t, goodKey))
+
+	candidates, err := newFileStore(dir).Candidates(context.Background())
+	require.NoError(t, err)
+	require.Len(t, candidates, 1, "only the certificate whose key matches is a candidate")
+	assert.True(t, good.Equal(candidates[0].Chain[0]), "the matching pair is kept")
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	now := time.Now()
+	nonce := challenger.Nonce(peerKey, now)
+	proofs := CollectChallenges(context.Background(), newFileStore(dir), []*proto.CertificateChallenge{{Nonce: nonce, CaCertificates: []string{ca.PEM}}}, peerKey)
+	require.Len(t, proofs, 1)
+	_, err = challenger.Verify(proofs[0], peerKey, now)
+	assert.NoError(t, err, "the proof sent is one management accepts")
+}
+
+// staticStore hands out fixed candidates, for scenarios no on-disk layout can express.
+type staticStore []Candidate
+
+func (s staticStore) Candidates(context.Context) ([]Candidate, error) { return s, nil }
+
+func TestCollectChallenges_RoutesAroundExpiredCopyOfRenewedIntermediate(t *testing.T) {
+	root := certtest.NewCA(t, "root")
+	intermediate := certtest.NewIntermediate(t, root, "issuing-ca")
+
+	// Renewing a CA with the same key pair leaves two certificates with the same
+	// subject and key in the store. The expired one sorts first here.
+	expiredTmpl := *intermediate.Cert
+	expiredTmpl.SerialNumber = big.NewInt(1)
+	expiredTmpl.NotBefore = time.Now().Add(-72 * time.Hour)
+	expiredTmpl.NotAfter = time.Now().Add(-48 * time.Hour)
+	der, err := x509.CreateCertificate(rand.Reader, &expiredTmpl, root.Cert, intermediate.Key.Public(), root.Key)
+	require.NoError(t, err)
+	expired, err := x509.ParseCertificate(der)
+	require.NoError(t, err)
+
+	key := certtest.ECDSAKey(t)
+	leaf := intermediate.Issue(t, key, "device")
+	pool := []*x509.Certificate{expired, intermediate.Cert}
+
+	chain := buildChain(leaf, pool)
+	require.Len(t, chain, 2)
+	require.True(t, expired.Equal(chain[1]), "precondition: the first-match chain runs through the expired copy")
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	now := time.Now()
+	nonce := challenger.Nonce(peerKey, now)
+	store := staticStore{{Chain: chain, Signer: key, Intermediates: pool}}
+
+	proofs := CollectChallenges(context.Background(), store, []*proto.CertificateChallenge{{Nonce: nonce, CaCertificates: []string{root.PEM}}}, peerKey)
+
+	require.Len(t, proofs, 1, "a valid path through the renewed intermediate exists, so the challenge is answered")
+	verified, err := challenger.Verify(proofs[0], peerKey, now)
+	require.NoError(t, err)
+	assert.True(t, intermediate.Cert.Equal(verified[1]), "the proof carries the valid intermediate, not the expired copy")
+	assert.True(t, certposture.ChainMatchesCAs(certposture.EncodeChainPEM(verified), []string{root.PEM}, now),
+		"management's own check accepts the chain the proof carries")
+}
+
+func TestCollectChallenges_ProvesALeafOncePerDistinctChain(t *testing.T) {
+	rootA := certtest.NewCA(t, "root-a")
+	rootB := certtest.NewCA(t, "root-b")
+	issuer := certtest.NewIntermediate(t, rootA, "issuing-ca")
+
+	// The same issuing CA cross-signed by a second root: one leaf, two valid paths.
+	crossTmpl := *issuer.Cert
+	crossTmpl.SerialNumber = big.NewInt(2)
+	der, err := x509.CreateCertificate(rand.Reader, &crossTmpl, rootB.Cert, issuer.Key.Public(), rootB.Key)
+	require.NoError(t, err)
+	cross, err := x509.ParseCertificate(der)
+	require.NoError(t, err)
+
+	key := certtest.ECDSAKey(t)
+	leaf := issuer.Issue(t, key, "device")
+	pool := []*x509.Certificate{issuer.Cert, cross}
+	store := staticStore{{Chain: buildChain(leaf, pool), Signer: key, Intermediates: pool}}
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	now := time.Now()
+	nonce := challenger.Nonce(peerKey, now)
+	challenges := []*proto.CertificateChallenge{
+		{Nonce: nonce, CaCertificates: []string{rootA.PEM}},
+		{Nonce: nonce, CaCertificates: []string{rootB.PEM}},
+		{Nonce: nonce, CaCertificates: []string{rootA.PEM}},
+	}
+
+	proofs := CollectChallenges(context.Background(), store, challenges, peerKey)
+
+	require.Len(t, proofs, 2, "one proof per distinct chain, the repeated root-a challenge reuses the first")
+	for _, root := range []*certtest.CA{rootA, rootB} {
+		matched := false
+		for _, p := range proofs {
+			chain, err := challenger.Verify(p, peerKey, now)
+			require.NoError(t, err)
+			matched = matched || certposture.ChainMatchesCAs(certposture.EncodeChainPEM(chain), []string{root.PEM}, now)
+		}
+		assert.True(t, matched, "management can match a chain for the check that trusts %s", root.Cert.Subject.CommonName)
+	}
+}

client/internal/certproof/collect_windows.go

@@ -0,0 +1,108 @@
+package certproof
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+const helperTimeout = 30 * time.Second
+
+// CollectProofs answers the certificate challenges in checks from every store this
+// machine can reach. The service reads the local machine store itself, where AD and
+// Intune enrol device certificates, and reaches the signed-in user's store by launching
+// a helper with that session's token. A machine at the sign-in screen therefore proves
+// device certificates alone.
+func CollectProofs(ctx context.Context, checks []*proto.Checks, peerKey []byte, cfg Config) []certposture.Proof {
+	challenges := certificateChallenges(checks)
+	if len(challenges) == 0 {
+		logNoChallenges(checks)
+		return nil
+	}
+
+	proofs := CollectChallenges(ctx, DefaultStore(), challenges, peerKey)
+
+	// The helper already runs as the signed-in user, and an ordinary process has no
+	// right to a session token, so only the service goes looking for one.
+	if !runningAsLocalSystem() || cfg.OwnerUnknown {
+		return proofs
+	}
+
+	userProofs, err := collectAsDesktopUser(ctx, cfg.ProfileOwner, challenges, peerKey)
+	if err != nil {
+		log.Debugf("certificate posture: user certificate store unavailable: %v", err)
+	}
+	return mergeProofs(proofs, userProofs)
+}
+
+// UserContext identifies the session whose store a collection would include: a session
+// of the profile owner, or empty when no user store would be asked. A change means a
+// collection made earlier no longer reflects what this machine can prove.
+func UserContext(cfg Config) string {
+	if !runningAsLocalSystem() || cfg.OwnerUnknown {
+		return ""
+	}
+	user, ok := currentDesktopUser(cfg.ProfileOwner)
+	if !ok {
+		return ""
+	}
+	defer user.Close()
+	return fmt.Sprintf("%d:%s", user.Session, user.Name)
+}
+
+// helperStore is the store the helper reads. It runs as the signed-in user, so it wants
+// that user's store rather than the machine store the service already read.
+func helperStore() Store {
+	return newUserStore()
+}
+
+// collectAsDesktopUser runs the helper inside the interactive session of the signed-in
+// user. Unlike a keychain on macOS, a Windows service can assume a user identity
+// directly, so the session token goes straight into the child process.
+func collectAsDesktopUser(ctx context.Context, owner string, challenges []*proto.CertificateChallenge, peerKey []byte) ([]certposture.Proof, error) {
+	user, ok := currentDesktopUser(owner)
+	if !ok {
+		return nil, nil
+	}
+	defer user.Close()
+
+	binary, err := os.Executable()
+	if err != nil {
+		return nil, fmt.Errorf("resolve own binary: %w", err)
+	}
+
+	// The user's own environment, not the service's: the service environment may carry
+	// secrets such as a setup key that the signed-in user must not be able to read.
+	env, err := user.Token.Environ(false)
+	if err != nil {
+		return nil, fmt.Errorf("build environment of %s: %w", user.Name, err)
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, helperTimeout)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, binary, "posture", "cert-proof")
+	cmd.Env = env
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Token:         syscall.Token(user.Token),
+		HideWindow:    true,
+		CreationFlags: windows.CREATE_NO_WINDOW,
+	}
+
+	log.Debugf("certificate posture: asking session %d to answer %d challenges", user.Session, len(challenges))
+	proofs, err := runHelperCmd(cmd, helperRequest(challenges, peerKey))
+	if err != nil {
+		return nil, fmt.Errorf("run helper in session %d: %w", user.Session, err)
+	}
+	log.Debugf("certificate posture: session %d returned %d proofs", user.Session, len(proofs))
+	return proofs, nil
+}

client/internal/certproof/collector.go

@@ -0,0 +1,189 @@
+package certproof
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+const (
+	collectTimeout = 45 * time.Second
+
+	// lostAfter is how many deadlines an abandoned collection is waited for before a new
+	// one may start beside it. A store that is merely slow finishes well within that and
+	// releases its slot; only one wedged for good is worked around.
+	lostAfter = 10
+
+	// maxInFlight bounds how many abandoned collections may pile up. A store that never
+	// answers would otherwise leak a goroutine on every collection for the life of the
+	// daemon.
+	maxInFlight = 2
+)
+
+// collectSlots tracks the collections running in the process. Collectors share one by
+// default: a collection abandoned in a token, TPM or keychain call keeps running after
+// the engine that started it has stopped, and the next engine must account for it.
+type collectSlots struct {
+	mu   sync.Mutex
+	next uint64
+	// running holds the start time of each collection still running, by slot id.
+	running map[uint64]time.Time
+}
+
+var processSlots collectSlots
+
+// Collector runs CollectProofs with a deadline and, in the normal case, one collection
+// at a time in the process. Token, TPM and keychain calls cannot be interrupted, and on
+// Linux there is not even a process to kill, so a collection that overruns is abandoned
+// rather than awaited. A single wedged call would then refuse every later collection for
+// the life of the daemon, so once an abandoned collection has been running for lostAfter
+// deadlines another may start beside it, up to maxInFlight. The zero value is ready to
+// use.
+type Collector struct {
+	// slots overrides the process-wide slots when set.
+	slots *collectSlots
+	// timeout overrides collectTimeout when set.
+	timeout time.Duration
+	// now overrides the clock when set.
+	now func() time.Time
+}
+
+// Collect answers the certificate challenges in checks, returning no proofs when there
+// are no challenges, when previous collections still hold the slots, or when this one
+// does not finish in time. Missing proofs fail the certificate check on management.
+func (c *Collector) Collect(ctx context.Context, checks []*proto.Checks, peerKey []byte, cfg Config) []certposture.Proof {
+	return c.collect(ctx, checks, func(ctx context.Context) []certposture.Proof {
+		return CollectProofs(ctx, checks, peerKey, cfg)
+	})
+}
+
+func (c *Collector) collect(ctx context.Context, checks []*proto.Checks, run func(context.Context) []certposture.Proof) []certposture.Proof {
+	if len(certificateChallenges(checks)) == 0 {
+		return nil
+	}
+	slots := c.slotsInUse()
+	slot, ok := slots.start(c.clock(), time.Duration(lostAfter)*c.deadline())
+	if !ok {
+		return nil
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, c.deadline())
+	defer cancel()
+
+	done := make(chan []certposture.Proof, 1)
+	go func() {
+		// The slot is freed before the result is delivered, so a caller that starts the
+		// next collection right after this one returned is not turned away.
+		proofs := run(ctx)
+		slots.finish(slot)
+		done <- proofs
+	}()
+
+	select {
+	case proofs := <-done:
+		return proofs
+	case <-ctx.Done():
+		log.Warnf("certificate posture: proof collection did not finish within %s, sending no proofs", c.deadline())
+		return nil
+	}
+}
+
+// Stuck reports whether lost collections hold every slot. No collection starts again
+// until one of them returns, which for a store that never answers means a restart.
+func (c *Collector) Stuck() bool {
+	return c.slotsInUse().allLost(c.clock(), time.Duration(lostAfter)*c.deadline())
+}
+
+func (c *Collector) slotsInUse() *collectSlots {
+	if c.slots != nil {
+		return c.slots
+	}
+	return &processSlots
+}
+
+func (c *Collector) clock() time.Time {
+	if c.now != nil {
+		return c.now()
+	}
+	return time.Now()
+}
+
+func (c *Collector) deadline() time.Duration {
+	if c.timeout > 0 {
+		return c.timeout
+	}
+	return collectTimeout
+}
+
+// start claims a slot at now, reporting its id and whether the caller may collect. A
+// collection that has held a slot for lost is taken to be wedged.
+func (s *collectSlots) start(now time.Time, lost time.Duration) (uint64, bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if len(s.running) > 0 {
+		oldest := s.oldest()
+		switch {
+		case len(s.running) >= maxInFlight:
+			log.Warnf("certificate posture: %d proof collections are wedged, sending no proofs", len(s.running))
+			return 0, false
+		case now.Sub(oldest) < lost:
+			log.Warnf("certificate posture: previous proof collection is still running, sending no proofs")
+			return 0, false
+		default:
+			log.Warnf("certificate posture: a proof collection has been stuck since %s, starting another", oldest.Format(time.RFC3339))
+		}
+	}
+	if s.running == nil {
+		s.running = make(map[uint64]time.Time, maxInFlight)
+	}
+	s.next++
+	s.running[s.next] = now
+	return s.next, true
+}
+
+// finish releases the slot with the given id.
+func (s *collectSlots) finish(slot uint64) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	delete(s.running, slot)
+}
+
+// allLost reports whether every slot is held by a collection that has run for lost.
+func (s *collectSlots) allLost(now time.Time, lost time.Duration) bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.running) < maxInFlight {
+		return false
+	}
+	for _, started := range s.running {
+		if now.Sub(started) < lost {
+			return false
+		}
+	}
+	return true
+}
+
+// idle reports whether no collection is running.
+func (s *collectSlots) idle() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return len(s.running) == 0
+}
+
+// oldest returns the start time of the longest-running collection. The caller holds mu
+// and has checked that one is running.
+func (s *collectSlots) oldest() time.Time {
+	var oldest time.Time
+	for _, started := range s.running {
+		if oldest.IsZero() || started.Before(oldest) {
+			oldest = started
+		}
+	}
+	return oldest
+}

client/internal/certproof/collector_test.go

@@ -0,0 +1,207 @@
+package certproof
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+var challengeChecks = []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{
+	Nonce: certposture.NewChallenger([]byte("secret")).Nonce(peerKey, time.Now()),
+}}}
+
+func TestCollector_SkipsChecksWithoutChallenges(t *testing.T) {
+	var c Collector
+	called := false
+
+	proofs := c.collect(context.Background(), []*proto.Checks{{Files: []string{"/bin/agent"}}}, func(context.Context) []certposture.Proof {
+		called = true
+		return nil
+	})
+
+	assert.Nil(t, proofs)
+	assert.False(t, called, "no store is touched when no check carries a challenge")
+}
+
+func TestCollector_ReturnsProofs(t *testing.T) {
+	var c Collector
+	want := []certposture.Proof{{Nonce: []byte("nonce")}}
+
+	proofs := c.collect(context.Background(), challengeChecks, func(context.Context) []certposture.Proof { return want })
+
+	assert.Equal(t, want, proofs, "a collection that finishes in time is returned as is")
+}
+
+func TestCollector_AbandonsStuckCollection(t *testing.T) {
+	c := Collector{timeout: 50 * time.Millisecond, slots: &collectSlots{}}
+	release := make(chan struct{})
+	finished := make(chan struct{})
+
+	// A token or keychain call that ignores its context and blocks well past the deadline.
+	stuck := func(context.Context) []certposture.Proof {
+		defer close(finished)
+		<-release
+		return []certposture.Proof{{Nonce: []byte("late")}}
+	}
+
+	start := time.Now()
+	proofs := c.collect(context.Background(), challengeChecks, stuck)
+	assert.Nil(t, proofs, "an overrunning collection yields no proofs")
+	assert.Less(t, time.Since(start), time.Second, "the caller is released at the deadline, not when the call returns")
+
+	called := false
+	proofs = c.collect(context.Background(), challengeChecks, func(context.Context) []certposture.Proof {
+		called = true
+		return nil
+	})
+	assert.Nil(t, proofs)
+	assert.False(t, called, "no second collection starts while the first is still running")
+
+	close(release)
+	<-finished
+	require.Eventually(t, func() bool { return c.slots.idle() }, time.Second, 5*time.Millisecond, "the collector frees up once the stuck call returns")
+
+	want := []certposture.Proof{{Nonce: []byte("nonce")}}
+	assert.Equal(t, want, c.collect(context.Background(), challengeChecks, func(context.Context) []certposture.Proof { return want }),
+		"collection works again after the stuck call returned")
+}
+
+func TestCollector_CancelsContextAtDeadline(t *testing.T) {
+	c := Collector{timeout: 20 * time.Millisecond, slots: &collectSlots{}}
+	cancelled := make(chan struct{})
+
+	c.collect(context.Background(), challengeChecks, func(ctx context.Context) []certposture.Proof {
+		<-ctx.Done()
+		close(cancelled)
+		return nil
+	})
+
+	select {
+	case <-cancelled:
+	case <-time.After(time.Second):
+		t.Fatal("a collection that honours its context, like the helper process, must see it cancelled")
+	}
+}
+
+// TestCollector_SingleFlightAcrossCollectors: each engine has its own Collector, and a
+// collection stuck in a token call outlives the engine that started it, so the next
+// engine's Collector must not start another one until it has finished.
+func TestCollector_SingleFlightAcrossCollectors(t *testing.T) {
+	shared := &collectSlots{}
+	first := Collector{timeout: 20 * time.Millisecond, slots: shared}
+	second := Collector{timeout: time.Second, slots: shared}
+
+	release := make(chan struct{})
+	stuck := func(context.Context) []certposture.Proof {
+		<-release
+		return nil
+	}
+	assert.Nil(t, first.collect(context.Background(), challengeChecks, stuck), "the first collection is abandoned at its deadline")
+
+	called := false
+	proofs := second.collect(context.Background(), challengeChecks, func(context.Context) []certposture.Proof {
+		called = true
+		return []certposture.Proof{{}}
+	})
+	assert.Nil(t, proofs, "no proofs while the abandoned collection still runs")
+	assert.False(t, called, "a second collection does not start on top of the abandoned one")
+
+	close(release)
+	require.Eventually(t, func() bool { return shared.idle() }, time.Second, 5*time.Millisecond)
+	assert.Len(t, second.collect(context.Background(), challengeChecks, func(context.Context) []certposture.Proof { return []certposture.Proof{{}} }), 1,
+		"collections resume once the abandoned one finished")
+}
+
+// TestCollector_ZeroValuesShareTheProcessFlag: the zero value uses the process-wide flag.
+func TestCollector_ZeroValuesShareTheProcessFlag(t *testing.T) {
+	var a, b Collector
+	assert.Same(t, a.slotsInUse(), b.slotsInUse(), "separate Collectors share the process slots")
+}
+
+// TestCollector_LostCollectionDoesNotBlockForever: a store call that never answers, such
+// as a wedged token on Linux where there is no process to kill, must not refuse every
+// later collection. Once it has run for lostAfter deadlines another starts beside it,
+// and no more than maxInFlight ever run.
+func TestCollector_LostCollectionDoesNotBlockForever(t *testing.T) {
+	now := time.Now()
+	slots := &collectSlots{}
+	c := Collector{timeout: 10 * time.Millisecond, slots: slots, now: func() time.Time { return now }}
+
+	release := make(chan struct{})
+	defer close(release)
+	var started atomic.Int32
+	wedged := func(context.Context) []certposture.Proof {
+		started.Add(1)
+		<-release
+		return nil
+	}
+
+	c.collect(context.Background(), challengeChecks, wedged)
+	waitStarted(t, &started, 1)
+	c.collect(context.Background(), challengeChecks, wedged)
+	assert.Equal(t, int32(1), started.Load(), "a second collection is refused while the first may still finish")
+	assert.False(t, c.Stuck(), "one slow collection is not stuck yet")
+
+	now = now.Add(time.Duration(lostAfter) * c.deadline())
+	c.collect(context.Background(), challengeChecks, wedged)
+	waitStarted(t, &started, 2)
+	assert.False(t, c.Stuck(), "the second collection may still return, so the collector is not stuck yet")
+
+	now = now.Add(time.Duration(lostAfter) * c.deadline())
+	c.collect(context.Background(), challengeChecks, wedged)
+	assert.Equal(t, int32(2), started.Load(), "no more than maxInFlight collections run")
+	assert.True(t, c.Stuck(), "with every slot held by a lost collection the collector reports itself stuck")
+}
+
+// TestCollector_LostWindowFollowsTheOldestRunningCollection: A wedges, B starts beside it
+// once A counts as lost, then A returns. B is recent, so a third collection must wait for
+// B to be lost in its own right rather than inherit A's start time.
+func TestCollector_LostWindowFollowsTheOldestRunningCollection(t *testing.T) {
+	now := time.Now()
+	slots := &collectSlots{}
+	c := Collector{timeout: 10 * time.Millisecond, slots: slots, now: func() time.Time { return now }}
+	lost := time.Duration(lostAfter) * c.deadline()
+
+	releaseA := make(chan struct{})
+	releaseB := make(chan struct{})
+	defer close(releaseB)
+	var started atomic.Int32
+	blockOn := func(release chan struct{}) func(context.Context) []certposture.Proof {
+		return func(context.Context) []certposture.Proof {
+			started.Add(1)
+			<-release
+			return nil
+		}
+	}
+
+	c.collect(context.Background(), challengeChecks, blockOn(releaseA))
+	waitStarted(t, &started, 1)
+	now = now.Add(lost)
+	c.collect(context.Background(), challengeChecks, blockOn(releaseB))
+	waitStarted(t, &started, 2)
+
+	close(releaseA)
+	require.Eventually(t, func() bool {
+		slots.mu.Lock()
+		defer slots.mu.Unlock()
+		return len(slots.running) == 1
+	}, time.Second, 5*time.Millisecond, "A frees its slot once it returns")
+
+	c.collect(context.Background(), challengeChecks, blockOn(make(chan struct{})))
+	assert.Equal(t, int32(2), started.Load(), "a third collection waits while B is recent")
+}
+
+// waitStarted waits for the collections the test launched to have started. collect may
+// return at its deadline before the goroutine running the store call was scheduled.
+func waitStarted(t *testing.T, started *atomic.Int32, n int32) {
+	t.Helper()
+	require.Eventually(t, func() bool { return started.Load() == n }, time.Second, time.Millisecond,
+		"%d collections should have started", n)
+}

client/internal/certproof/consoleuser_darwin.go

@@ -0,0 +1,123 @@
+//go:build !ios
+
+package certproof
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"sync"
+
+	"github.com/ebitengine/purego"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	systemConfigurationFramework = "/System/Library/Frameworks/SystemConfiguration.framework/SystemConfiguration"
+
+	encodingUTF8       = 0x08000100
+	consoleNameBufSize = 256
+)
+
+var (
+	consoleOnce sync.Once
+	consoleErr  error
+
+	scDynamicStoreCopyConsoleUser func(store uintptr, uid, gid *uint32) uintptr
+	cfStringGetCString            func(str uintptr, buffer *byte, size int, encoding uint32) bool
+)
+
+// ConsoleUser is the account whose desktop session owns the display. Its login keychain
+// is the only user keychain a NetBird daemon can reach, and only while it is logged in.
+type ConsoleUser struct {
+	Name string
+	UID  uint32
+	GID  uint32
+}
+
+// currentConsoleUser reports the user sitting at the desktop. The second return value is
+// false when nobody is: at the login window macOS either reports no console user at all
+// or attributes the session to root, and neither has a login keychain to offer.
+func currentConsoleUser() (ConsoleUser, bool) {
+	if err := loadConsoleUser(); err != nil {
+		log.Debugf("console user lookup unavailable: %v", err)
+		return ConsoleUser{}, false
+	}
+
+	var uid, gid uint32
+	name := scDynamicStoreCopyConsoleUser(0, &uid, &gid)
+	if name == 0 {
+		log.Debug("no console user is logged in, no login keychain is reachable")
+		return ConsoleUser{}, false
+	}
+	defer release(name)
+
+	user := ConsoleUser{Name: cfString(name), UID: uid, GID: gid}
+	if !user.hasDesktop() {
+		log.Debugf("console session belongs to %q uid=%d, which is not a desktop login, no login keychain is reachable", user.Name, user.UID)
+		return ConsoleUser{}, false
+	}
+	return user, true
+}
+
+// hasDesktop reports whether the console session is a real user desktop. The login
+// window runs as root and some macOS releases name it "loginwindow" instead.
+func (u ConsoleUser) hasDesktop() bool {
+	switch u.Name {
+	case "", "root", "loginwindow":
+		return false
+	}
+	return u.UID != 0
+}
+
+// isOwner reports whether the console user is owner, the account of the active profile,
+// which is recorded as a short user name or, for an account without one, a numeric uid.
+// With no owner the console user counts, as macOS has a single console user.
+func (u ConsoleUser) isOwner(owner string) bool {
+	return owner == "" || owner == u.Name || owner == strconv.FormatUint(uint64(u.UID), 10)
+}
+
+func cfString(str uintptr) string {
+	buf := make([]byte, consoleNameBufSize)
+	if !cfStringGetCString(str, &buf[0], len(buf), encodingUTF8) {
+		return ""
+	}
+	if end := bytes.IndexByte(buf, 0); end >= 0 {
+		return string(buf[:end])
+	}
+	return string(buf)
+}
+
+// loadConsoleUser resolves the console user symbols. It loads the keychain bindings
+// first because CFRelease is resolved there and released strings depend on it.
+func loadConsoleUser() error {
+	if err := loadKeychain(); err != nil {
+		return err
+	}
+	consoleOnce.Do(func() { consoleErr = resolveConsoleUser() })
+	return consoleErr
+}
+
+func resolveConsoleUser() error {
+	systemConfiguration, err := purego.Dlopen(systemConfigurationFramework, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+	if err != nil {
+		return fmt.Errorf("open %s: %w", systemConfigurationFramework, err)
+	}
+	coreFoundation, err := purego.Dlopen(coreFoundationFramework, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+	if err != nil {
+		return fmt.Errorf("open %s: %w", coreFoundationFramework, err)
+	}
+
+	symbol, err := purego.Dlsym(systemConfiguration, "SCDynamicStoreCopyConsoleUser")
+	if err != nil {
+		return fmt.Errorf("resolve SCDynamicStoreCopyConsoleUser: %w", err)
+	}
+	purego.RegisterFunc(&scDynamicStoreCopyConsoleUser, symbol)
+
+	symbol, err = purego.Dlsym(coreFoundation, "CFStringGetCString")
+	if err != nil {
+		return fmt.Errorf("resolve CFStringGetCString: %w", err)
+	}
+	purego.RegisterFunc(&cfStringGetCString, symbol)
+	return nil
+}

client/internal/certproof/consoleuser_darwin_test.go

@@ -0,0 +1,51 @@
+//go:build !ios
+
+package certproof
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestConsoleUser_OnlyADesktopSessionCanBeValidated(t *testing.T) {
+	tests := []struct {
+		name    string
+		user    ConsoleUser
+		desktop bool
+	}{
+		{"logged in user", ConsoleUser{Name: "maycon", UID: 501, GID: 20}, true},
+		{"login window as root", ConsoleUser{Name: "root", UID: 0}, false},
+		{"login window by name", ConsoleUser{Name: "loginwindow", UID: 0}, false},
+		{"named user still at uid 0", ConsoleUser{Name: "admin", UID: 0}, false},
+		{"no console user", ConsoleUser{}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.desktop, tt.user.hasDesktop(), "only a real desktop session offers a login keychain")
+		})
+	}
+}
+
+// currentConsoleUser runs against the real SystemConfiguration framework. A machine with
+// a desktop open must report a non-root user; a headless runner must report none.
+func TestCurrentConsoleUser_AgreesWithItself(t *testing.T) {
+	user, ok := currentConsoleUser()
+	if !ok {
+		t.Log("no console user, running headless")
+		return
+	}
+	assert.NotEmpty(t, user.Name, "a console user must have a name")
+	assert.NotZero(t, user.UID, "a desktop session never belongs to uid 0")
+	assert.True(t, user.hasDesktop(), "a reported console user must be a desktop session")
+}
+
+func TestConsoleUser_IsOwner(t *testing.T) {
+	user := ConsoleUser{Name: "maycon", UID: 501, GID: 20}
+
+	assert.True(t, user.isOwner(""), "a profile without owner accepts the single console user")
+	assert.True(t, user.isOwner("maycon"), "the owner by short name")
+	assert.True(t, user.isOwner("501"), "the owner recorded as a numeric uid")
+	assert.False(t, user.isOwner("viktor"), "another account's profile must not read this user's keychain")
+	assert.False(t, user.isOwner("502"), "another uid is another account")
+}

client/internal/certproof/desktopuser_windows.go

@@ -0,0 +1,182 @@
+package certproof
+
+import (
+	"fmt"
+	"strings"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+const (
+	noActiveSession = 0xFFFFFFFF
+	servicesSession = 0
+
+	// wtsCurrentServer is WTS_CURRENT_SERVER_HANDLE, which x/sys/windows does not export.
+	wtsCurrentServer = windows.Handle(0)
+)
+
+// DesktopUser is an interactive session and the account signed into it. The user's
+// certificate store is readable only from a process running as that account, because
+// its private keys are protected against the user profile rather than the machine.
+type DesktopUser struct {
+	Session uint32
+	Name    string
+	Token   windows.Token
+}
+
+// Close releases the session token.
+func (u DesktopUser) Close() {
+	if err := u.Token.Close(); err != nil {
+		log.Debugf("failed closing desktop session token: %v", err)
+	}
+}
+
+// currentDesktopUser returns a token for the session whose certificate store should be
+// asked: a session of owner, the account the active profile belongs to, with the
+// physical console preferred over remote sessions. With no owner only the console user
+// counts. Picking any signed-in user instead would let whoever else is logged in to a
+// terminal server or VDI host decide the result. The second return is false when no
+// such session exists, and only machine certificates can then be proven.
+//
+// Obtaining the token needs SE_TCB_NAME, which the LocalSystem service has and an
+// ordinary process does not.
+func currentDesktopUser(owner string) (DesktopUser, bool) {
+	console := windows.WTSGetActiveConsoleSessionId()
+	if owner == "" {
+		return consoleUser(console)
+	}
+
+	sessions, err := userSessions(console)
+	if err != nil {
+		log.Debugf("cannot enumerate terminal sessions: %v", err)
+		return DesktopUser{}, false
+	}
+	var found DesktopUser
+	var ok bool
+	for _, session := range sessions {
+		user, signedIn := desktopUser(session)
+		if !signedIn {
+			continue
+		}
+		switch {
+		case !sameAccountName(user.Name, owner):
+			user.Close()
+		case !ok:
+			found, ok = user, true
+		case strings.EqualFold(user.Name, found.Name):
+			// Another session of the same account; the first one in preference order wins.
+			user.Close()
+		default:
+			// An owner recorded without a domain matches accounts of several domains here.
+			// Picking one would let another domain's user answer for the owner.
+			log.Debugf("certificate posture: profile owner %s matches both %s and %s, no user certificate store is used", owner, found.Name, user.Name)
+			user.Close()
+			found.Close()
+			return DesktopUser{}, false
+		}
+	}
+	if !ok {
+		log.Debugf("certificate posture: profile owner %s has no signed-in session, no user certificate store is reachable", owner)
+	}
+	return found, ok
+}
+
+func consoleUser(console uint32) (DesktopUser, bool) {
+	if console == noActiveSession || console == servicesSession {
+		log.Debug("no console session, no user certificate store is reachable")
+		return DesktopUser{}, false
+	}
+	user, ok := desktopUser(console)
+	if !ok {
+		log.Debugf("console session %d has nobody signed in, no user certificate store is reachable", console)
+	}
+	return user, ok
+}
+
+// sameAccountName compares DOMAIN\account names case-insensitively, as Windows does, and an
+// owner given without a domain against the account part alone. The session side comes from
+// the session token's own SID, which Windows resolves from its cache of signed-in users.
+// Resolving the owner name to a SID instead would ask the domain controller, which on a
+// laptop that cannot reach it yet blocks for tens of seconds, past the collection deadline.
+func sameAccountName(sessionName, owner string) bool {
+	if strings.EqualFold(sessionName, owner) {
+		return true
+	}
+	if strings.Contains(owner, `\`) {
+		return false
+	}
+	_, account, found := strings.Cut(sessionName, `\`)
+	return found && strings.EqualFold(account, owner)
+}
+
+func desktopUser(session uint32) (DesktopUser, bool) {
+	var token windows.Token
+	if err := windows.WTSQueryUserToken(session, &token); err != nil {
+		log.Debugf("no user token for session %d: %v", session, err)
+		return DesktopUser{}, false
+	}
+
+	name, err := tokenAccount(token)
+	if err != nil {
+		log.Debugf("session %d token has no readable account: %v", session, err)
+		if closeErr := token.Close(); closeErr != nil {
+			log.Debugf("failed closing session token: %v", closeErr)
+		}
+		return DesktopUser{}, false
+	}
+	return DesktopUser{Session: session, Name: name, Token: token}, true
+}
+
+func tokenAccount(token windows.Token) (string, error) {
+	user, err := token.GetTokenUser()
+	if err != nil {
+		return "", fmt.Errorf("read token user: %w", err)
+	}
+	account, domain, _, err := user.User.Sid.LookupAccount("")
+	if err != nil {
+		return "", fmt.Errorf("look up account: %w", err)
+	}
+	if domain == "" {
+		return account, nil
+	}
+	return domain + `\` + account, nil
+}
+
+// userSessions lists the sessions a user can be signed in to, console first, then
+// active remote sessions, then disconnected ones, whose user is still signed in. Session
+// 0 is skipped: it hosts services and never belongs to an interactive user.
+func userSessions(console uint32) ([]uint32, error) {
+	var info *windows.WTS_SESSION_INFO
+	var count uint32
+	if err := windows.WTSEnumerateSessions(wtsCurrentServer, 0, 1, &info, &count); err != nil {
+		return nil, fmt.Errorf("enumerate sessions: %w", err)
+	}
+	defer windows.WTSFreeMemory(uintptr(unsafe.Pointer(info)))
+
+	var sessions []uint32
+	if console != noActiveSession && console != servicesSession {
+		sessions = append(sessions, console)
+	}
+	for _, state := range []uint32{windows.WTSActive, windows.WTSDisconnected} {
+		for _, session := range unsafe.Slice(info, count) {
+			if session.SessionID == servicesSession || session.SessionID == console || session.State != state {
+				continue
+			}
+			sessions = append(sessions, session.SessionID)
+		}
+	}
+	return sessions, nil
+}
+
+// runningAsLocalSystem reports whether this process is the service. The helper runs as
+// the signed-in user and must read its own store rather than launching another helper.
+func runningAsLocalSystem() bool {
+	user, err := windows.GetCurrentProcessToken().GetTokenUser()
+	if err != nil {
+		log.Debugf("failed reading own token user: %v", err)
+		return false
+	}
+	return user.User.Sid.IsWellKnown(windows.WinLocalSystemSid)
+}

client/internal/certproof/desktopuser_windows_test.go

@@ -0,0 +1,61 @@
+package certproof
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSameAccountName(t *testing.T) {
+	tests := []struct {
+		session, owner string
+		want           bool
+	}{
+		{`CORP\alice`, `CORP\alice`, true},
+		{`CORP\alice`, `corp\ALICE`, true},
+		{`CORP\alice`, `alice`, true},
+		{`CORP\alice`, `OTHER\alice`, false},
+		{`CORP\alice`, `bob`, false},
+		{`alice`, `alice`, true},
+		{`CORP\alice`, `CORP\alic`, false},
+	}
+	for _, tt := range tests {
+		assert.Equal(t, tt.want, sameAccountName(tt.session, tt.owner), "session %q, owner %q", tt.session, tt.owner)
+	}
+}
+
+// currentDesktopUser against the real session manager: an owner no session belongs to
+// must never yield a session, whoever else is signed in.
+func TestCurrentDesktopUser_UnknownOwnerHasNoSession(t *testing.T) {
+	user, ok := currentDesktopUser(`NO-SUCH-DOMAIN\no-such-user-netbird`)
+	if ok {
+		user.Close()
+	}
+	assert.False(t, ok, "a profile owner without a session must not borrow another user's store")
+}
+
+// TestCurrentDesktopUser_FindsTheOwnersSession runs against a real machine as LocalSystem,
+// with NB_TEST_DESKTOP_OWNER naming an account that is signed in. That account's session
+// must be found, and only that account's.
+func TestCurrentDesktopUser_FindsTheOwnersSession(t *testing.T) {
+	owner := os.Getenv("NB_TEST_DESKTOP_OWNER")
+	if owner == "" {
+		t.Skip("set NB_TEST_DESKTOP_OWNER to a signed-in account and run as LocalSystem")
+	}
+	user, ok := currentDesktopUser(owner)
+	require.True(t, ok, "the signed-in owner %s must have a session", owner)
+	defer user.Close()
+	t.Logf("owner %s resolved to session %d as %s", owner, user.Session, user.Name)
+	assert.True(t, sameAccountName(user.Name, owner), "the session found belongs to %s, not %s", owner, user.Name)
+	assert.NotZero(t, user.Session, "session 0 hosts services and never belongs to the owner")
+
+	console, consoleOK := currentDesktopUser("")
+	if consoleOK {
+		defer console.Close()
+		t.Logf("without an owner the console user counts: session %d as %s", console.Session, console.Name)
+	} else {
+		t.Log("without an owner nobody counts: no user at the console")
+	}
+}

client/internal/certproof/doc.go

@@ -0,0 +1,26 @@
+// Package certproof answers certificate posture challenges: it finds the certificates a
+// peer holds a private key for and signs the challenge nonce, bound to the peer's
+// WireGuard key, with that key. Management verifies the signature and the chain against
+// the CAs of the check, so only a holder of the key passes and a proof made for one peer
+// cannot be replayed by another. Keys in the OS stores, the TPM and a PKCS#11 token are
+// used through the platform, which signs; a plain PEM key file is the exception, parsed
+// and used in the daemon's memory.
+//
+// Machine stores are read by the daemon itself: the Windows LocalMachine store, the macOS
+// System keychain, and on Linux a directory of PEM files, TSS2 key files the TPM signs
+// with, and a PKCS#11 token. On Linux the directory and the token URI come from the
+// daemon's environment (NB_CERT_STORE_DIR, NB_CERT_PKCS11_URI), as does the token PIN
+// (NB_TPM_PIN); none of them is read from the profile config.
+//
+// User stores cannot be read by a privileged daemon, so it starts this binary as
+// "netbird posture cert-proof" inside the user's session and receives only signatures
+// and chains on its stdout. On macOS uid is not what unlocks a login keychain, the
+// session's bootstrap namespace is, which is why the helper enters it through launchctl
+// asuser. On Windows a service opening CURRENT_USER silently reads its own empty hive, so
+// the helper runs with the session's token instead. Its output is untrusted: sizes are
+// capped and only proofs for requested nonces are kept.
+//
+// A user proof shows that some process in that user's session could use a key whose
+// certificate chains to the CA. It does not show which binary signed, or that the key is
+// hardware-bound; device stores are the stronger signal.
+package certproof

client/internal/certproof/helper.go

@@ -0,0 +1,66 @@
+package certproof
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// HelperRequest is the work the daemon hands to a helper running in a user session. The
+// peer key binds every signature to this machine, so a proof cannot be replayed onto
+// another peer.
+type HelperRequest struct {
+	PeerKey    []byte            `json:"peerKey"`
+	Challenges []HelperChallenge `json:"challenges"`
+}
+
+// HelperChallenge is one certificate challenge in the form the helper needs.
+type HelperChallenge struct {
+	Nonce          []byte   `json:"nonce"`
+	CACertificates []string `json:"caCertificates"`
+}
+
+// HelperResponse carries the proofs the helper produced from its own keychain.
+type HelperResponse struct {
+	Proofs []certposture.Proof `json:"proofs"`
+}
+
+// RunHelper answers the challenges on in from the store of the user running this
+// process and writes the proofs to out. It is the child half of the console user
+// lookup: the daemon cannot read a login keychain, so it launches this in the user's
+// session instead. Only the signature crosses back, never the private key.
+func RunHelper(ctx context.Context, in io.Reader, out io.Writer) error {
+	return runHelper(ctx, helperStore(), in, out)
+}
+
+func runHelper(ctx context.Context, store Store, in io.Reader, out io.Writer) error {
+	var req HelperRequest
+	if err := json.NewDecoder(in).Decode(&req); err != nil {
+		return fmt.Errorf("decode helper request: %w", err)
+	}
+
+	challenges := make([]*proto.CertificateChallenge, 0, len(req.Challenges))
+	for _, challenge := range req.Challenges {
+		challenges = append(challenges, &proto.CertificateChallenge{
+			Nonce:          challenge.Nonce,
+			CaCertificates: challenge.CACertificates,
+		})
+	}
+
+	var proofs []certposture.Proof
+	if len(challenges) > 0 {
+		proofs = CollectChallenges(ctx, store, challenges, req.PeerKey)
+	}
+	log.Debugf("certificate posture helper: answering %d challenges with %d proofs", len(challenges), len(proofs))
+
+	if err := json.NewEncoder(out).Encode(HelperResponse{Proofs: proofs}); err != nil {
+		return fmt.Errorf("encode helper response: %w", err)
+	}
+	return nil
+}

client/internal/certproof/helper_backoff.go

@@ -0,0 +1,78 @@
+package certproof
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// helperQuietPeriod is how long a user whose helper proved nothing is not asked again
+// for the same CAs. On macOS each helper run may show a keychain prompt, so retrying on
+// every collection would put up a new one each time the user ignored or denied the last.
+const helperQuietPeriod = time.Hour
+
+// helperBackoff remembers, per user and set of CAs asked about, until when the helper
+// is not launched again because its last run proved nothing.
+type helperBackoff struct {
+	mu    sync.Mutex
+	until map[string]time.Time
+}
+
+func newHelperBackoff() *helperBackoff {
+	return &helperBackoff{until: map[string]time.Time{}}
+}
+
+// allow reports whether the helper may be launched for key now.
+func (b *helperBackoff) allow(key string, now time.Time) bool {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return !now.Before(b.until[key])
+}
+
+// record stores the outcome of a helper run for key: one that proved something clears
+// the back-off, one that proved nothing starts it. Expired entries are dropped, so the
+// map holds only users currently held off.
+func (b *helperBackoff) record(key string, proven bool, now time.Time) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	for other, until := range b.until {
+		if !now.Before(until) {
+			delete(b.until, other)
+		}
+	}
+	if proven {
+		delete(b.until, key)
+		return
+	}
+	b.until[key] = now.Add(helperQuietPeriod)
+}
+
+// helperBackoffKey identifies a user and the set of CAs the challenges accept, in any
+// order, leaving out the nonces, which rotate without changing what the user is asked to
+// prove.
+func helperBackoffKey(user string, challenges []*proto.CertificateChallenge) string {
+	sets := make([]string, 0, len(challenges))
+	for _, challenge := range challenges {
+		cas := make([]string, 0, len(challenge.GetCaCertificates()))
+		for _, ca := range challenge.GetCaCertificates() {
+			sum := sha256.Sum256([]byte(ca))
+			cas = append(cas, hex.EncodeToString(sum[:]))
+		}
+		slices.Sort(cas)
+		sets = append(sets, strings.Join(cas, ","))
+	}
+	slices.Sort(sets)
+
+	h := sha256.New()
+	h.Write([]byte(user))
+	for _, set := range sets {
+		h.Write([]byte{0})
+		h.Write([]byte(set))
+	}
+	return hex.EncodeToString(h.Sum(nil))
+}

client/internal/certproof/helper_backoff_test.go

@@ -0,0 +1,69 @@
+package certproof
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// TestHelperBackoff: a user whose helper proved nothing, for one ignoring or denying a
+// keychain prompt, is not asked again for the same CAs within the quiet period, while a
+// success or other CAs are asked at once.
+func TestHelperBackoff(t *testing.T) {
+	now := time.Now()
+	b := newHelperBackoff()
+	key := helperBackoffKey("501", []*proto.CertificateChallenge{{CaCertificates: []string{"ca-a"}}})
+
+	assert.True(t, b.allow(key, now), "a user never asked is asked")
+
+	b.record(key, false, now)
+	assert.False(t, b.allow(key, now.Add(helperQuietPeriod-time.Second)), "no new prompt within the quiet period")
+	assert.True(t, b.allow(key, now.Add(helperQuietPeriod)), "asked again once the quiet period passed")
+
+	other := helperBackoffKey("501", []*proto.CertificateChallenge{{CaCertificates: []string{"ca-b"}}})
+	assert.True(t, b.allow(other, now), "a check for other CAs is asked at once")
+	assert.True(t, b.allow(helperBackoffKey("502", []*proto.CertificateChallenge{{CaCertificates: []string{"ca-a"}}}), now), "another user is asked at once")
+
+	b.record(key, true, now)
+	assert.True(t, b.allow(key, now), "a run that proved something clears the quiet period")
+}
+
+// TestHelperBackoffKey_IgnoresNonces: nonces rotate every window without changing what
+// the user is asked to prove, so they do not reset the quiet period.
+func TestHelperBackoffKey_IgnoresNonces(t *testing.T) {
+	a := helperBackoffKey("501", []*proto.CertificateChallenge{{Nonce: []byte("one"), CaCertificates: []string{"ca"}}})
+	b := helperBackoffKey("501", []*proto.CertificateChallenge{{Nonce: []byte("two"), CaCertificates: []string{"ca"}}})
+	assert.Equal(t, a, b, "the key does not depend on the nonce")
+}
+
+// TestHelperBackoffKey_IgnoresOrder: the same CAs, listed in another order or with the
+// challenges reordered, are the same question to the user.
+func TestHelperBackoffKey_IgnoresOrder(t *testing.T) {
+	a := helperBackoffKey("501", []*proto.CertificateChallenge{
+		{CaCertificates: []string{"ca-1", "ca-2"}},
+		{CaCertificates: []string{"ca-3"}},
+	})
+	b := helperBackoffKey("501", []*proto.CertificateChallenge{
+		{CaCertificates: []string{"ca-3"}},
+		{CaCertificates: []string{"ca-2", "ca-1"}},
+	})
+	assert.Equal(t, a, b, "the key does not depend on the order of CAs or challenges")
+
+	c := helperBackoffKey("501", []*proto.CertificateChallenge{{CaCertificates: []string{"ca-1", "ca-2", "ca-3"}}})
+	assert.NotEqual(t, a, c, "the same CAs grouped into other challenges are another question")
+}
+
+// TestHelperBackoff_PrunesExpired: entries whose quiet period passed are dropped when the
+// next outcome is recorded, so the map does not grow with every user and CA set seen.
+func TestHelperBackoff_PrunesExpired(t *testing.T) {
+	now := time.Now()
+	b := newHelperBackoff()
+	b.record("old", false, now)
+	b.record("new", false, now.Add(helperQuietPeriod))
+
+	assert.NotContains(t, b.until, "old", "an expired entry is pruned")
+	assert.Contains(t, b.until, "new", "a current entry is kept")
+}

client/internal/certproof/helper_kill_other.go

@@ -0,0 +1,10 @@
+//go:build !unix && !windows
+
+package certproof
+
+import "os/exec"
+
+// startHelper starts cmd.
+func startHelper(cmd *exec.Cmd) (func(), error) {
+	return func() {}, cmd.Start()
+}

client/internal/certproof/helper_kill_unix.go

@@ -0,0 +1,35 @@
+//go:build unix
+
+package certproof
+
+import (
+	"errors"
+	"os/exec"
+	"syscall"
+)
+
+// killHelperGroupOnCancel puts cmd in a process group of its own and kills the whole
+// group when cmd's context ends. The helper may run below launchers such as launchctl
+// and sudo, which do not pass a kill on, and it keeps the output pipes open, so killing
+// only the direct child would leave the helper running and Wait blocked until the
+// helper exits on its own, for one waiting on a keychain prompt nobody answers.
+func killHelperGroupOnCancel(cmd *exec.Cmd) {
+	if cmd.SysProcAttr == nil {
+		cmd.SysProcAttr = &syscall.SysProcAttr{}
+	}
+	cmd.SysProcAttr.Setpgid = true
+	cmd.Cancel = func() error {
+		err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
+		if errors.Is(err, syscall.ESRCH) {
+			return nil
+		}
+		return err
+	}
+	cmd.WaitDelay = helperWaitDelay
+}
+
+// startHelper starts cmd. Killing the helper with everything below it is arranged by
+// killHelperGroupOnCancel where the helper runs under a launcher.
+func startHelper(cmd *exec.Cmd) (func(), error) {
+	return func() {}, cmd.Start()
+}

client/internal/certproof/helper_kill_windows.go

@@ -0,0 +1,77 @@
+//go:build windows
+
+package certproof
+
+import (
+	"fmt"
+	"os/exec"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+// startHelper starts cmd inside a job object that is terminated when cmd's context ends
+// and closed, killing whatever is left in it, once the helper has been awaited. Killing
+// only the helper on Windows leaves its descendants running, and one that holds the
+// output pipe would block Wait until it exits, so WaitDelay bounds that wait as well.
+func startHelper(cmd *exec.Cmd) (func(), error) {
+	job, err := newKillOnCloseJob()
+	if err != nil {
+		return nil, err
+	}
+	closeJob := func() {
+		if err := windows.CloseHandle(job); err != nil {
+			log.Debugf("failed to close certificate proof helper job: %v", err)
+		}
+	}
+
+	cmd.Cancel = func() error {
+		return windows.TerminateJobObject(job, 1)
+	}
+	cmd.WaitDelay = helperWaitDelay
+	if err := cmd.Start(); err != nil {
+		closeJob()
+		return nil, err
+	}
+
+	// A helper outside the job is still killed directly and bounded by WaitDelay; only
+	// its descendants would outlive it.
+	if err := assignToJob(job, cmd.Process.Pid); err != nil {
+		log.Debugf("failed to put certificate proof helper %d in its job: %v", cmd.Process.Pid, err)
+		cmd.Cancel = func() error { return cmd.Process.Kill() }
+	}
+	return closeJob, nil
+}
+
+// newKillOnCloseJob creates a job object whose processes are killed when its last handle
+// is closed.
+func newKillOnCloseJob() (windows.Handle, error) {
+	job, err := windows.CreateJobObject(nil, nil)
+	if err != nil {
+		return 0, fmt.Errorf("create job object: %w", err)
+	}
+	info := windows.JOBOBJECT_EXTENDED_LIMIT_INFORMATION{
+		BasicLimitInformation: windows.JOBOBJECT_BASIC_LIMIT_INFORMATION{
+			LimitFlags: windows.JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE,
+		},
+	}
+	if _, err := windows.SetInformationJobObject(job, windows.JobObjectExtendedLimitInformation,
+		uintptr(unsafe.Pointer(&info)), uint32(unsafe.Sizeof(info))); err != nil {
+		_ = windows.CloseHandle(job)
+		return 0, fmt.Errorf("set job object limits: %w", err)
+	}
+	return job, nil
+}
+
+// assignToJob puts the process pid into job.
+func assignToJob(job windows.Handle, pid int) error {
+	process, err := windows.OpenProcess(windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE, false, uint32(pid))
+	if err != nil {
+		return fmt.Errorf("open process: %w", err)
+	}
+	defer func() {
+		_ = windows.CloseHandle(process)
+	}()
+	return windows.AssignProcessToJobObject(job, process)
+}

client/internal/certproof/helper_kill_windows_test.go

@@ -0,0 +1,29 @@
+//go:build windows
+
+package certproof
+
+import (
+	"context"
+	"os/exec"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestRunHelperCmd_KillsHelperTree: the helper's child holds stdout and runs for a minute,
+// like a helper stuck below a launcher. Killing only the helper would leave Wait blocked
+// on the child's pipe until WaitDelay gives up; terminating the job ends both at once.
+func TestRunHelperCmd_KillsHelperTree(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, "cmd.exe", "/c", "ping -n 60 127.0.0.1")
+
+	start := time.Now()
+	_, err := runHelperCmd(cmd, HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}})
+
+	require.Error(t, err)
+	assert.Less(t, time.Since(start), helperWaitDelay, "the whole tree is killed at the timeout, not left for WaitDelay")
+}

client/internal/certproof/helper_run.go

@@ -0,0 +1,126 @@
+package certproof
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+)
+
+const (
+	maxHelperStdout = 1 << 20
+	maxHelperStderr = 4 << 10
+
+	// helperWaitDelay bounds how long a helper's output is awaited after it was killed.
+	helperWaitDelay = 2 * time.Second
+)
+
+var errHelperOutputTooLarge = errors.New("helper output exceeds the size limit")
+
+// runHelperCmd feeds req to the helper process cmd and returns the proofs it answered.
+// The helper runs as an unprivileged user who can control its output, so both streams
+// are capped and only proofs for a nonce req asked about are kept, one per challenge.
+func runHelperCmd(cmd *exec.Cmd, req HelperRequest) ([]certposture.Proof, error) {
+	payload, err := json.Marshal(req)
+	if err != nil {
+		return nil, fmt.Errorf("encode helper request: %w", err)
+	}
+
+	stdout := &cappedBuffer{limit: maxHelperStdout}
+	stderr := &cappedBuffer{limit: maxHelperStderr}
+	cmd.Stdin = bytes.NewReader(payload)
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+
+	release, err := startHelper(cmd)
+	if err != nil {
+		return nil, fmt.Errorf("start helper: %w", err)
+	}
+	defer release()
+	if err := cmd.Wait(); err != nil {
+		return nil, fmt.Errorf("%w: %s", err, strings.TrimSpace(stderr.String()))
+	}
+	logHelperStderr(stderr.String())
+	if stdout.truncated {
+		return nil, errHelperOutputTooLarge
+	}
+
+	var resp HelperResponse
+	if err := json.Unmarshal(stdout.Bytes(), &resp); err != nil {
+		return nil, fmt.Errorf("decode helper response: %w", err)
+	}
+	return requestedProofs(req, resp.Proofs), nil
+}
+
+// logHelperStderr records what a helper that succeeded wrote to stderr, such as a user
+// certificate it could not sign with, which is otherwise only visible in the user's
+// session. Each line is quoted because the helper's user controls its content.
+func logHelperStderr(stderr string) {
+	for _, line := range strings.Split(strings.TrimSpace(stderr), "\n") {
+		if line = strings.TrimSpace(line); line != "" {
+			log.Debugf("certificate posture helper: %q", line)
+		}
+	}
+}
+
+// requestedProofs keeps the proofs whose nonce belongs to one of req's challenges, at
+// most as many as req has challenges.
+func requestedProofs(req HelperRequest, proofs []certposture.Proof) []certposture.Proof {
+	var kept []certposture.Proof
+	for _, proof := range proofs {
+		if len(kept) == len(req.Challenges) {
+			break
+		}
+		if !req.asked(proof.Nonce) {
+			log.Debugf("certificate posture: dropping helper proof for a nonce that was not requested")
+			continue
+		}
+		kept = append(kept, proof)
+	}
+	return kept
+}
+
+func (r HelperRequest) asked(nonce []byte) bool {
+	for _, challenge := range r.Challenges {
+		if len(challenge.Nonce) > 0 && bytes.Equal(challenge.Nonce, nonce) {
+			return true
+		}
+	}
+	return false
+}
+
+// cappedBuffer keeps the first limit bytes written to it and discards the rest, so a
+// misbehaving child cannot grow the parent's memory without bound. The buffer is a
+// named field rather than embedded: an embedded bytes.Buffer would promote ReadFrom,
+// which io.Copy prefers over Write, bypassing the cap.
+type cappedBuffer struct {
+	buf       bytes.Buffer
+	limit     int
+	truncated bool
+}
+
+func (b *cappedBuffer) Write(p []byte) (int, error) {
+	if room := b.limit - b.buf.Len(); room < len(p) {
+		b.truncated = true
+		if room > 0 {
+			b.buf.Write(p[:room])
+		}
+		return len(p), nil
+	}
+	return b.buf.Write(p)
+}
+
+func (b *cappedBuffer) Bytes() []byte {
+	return b.buf.Bytes()
+}
+
+func (b *cappedBuffer) String() string {
+	return b.buf.String()
+}

client/internal/certproof/helper_run_test.go

@@ -0,0 +1,119 @@
+//go:build !windows && !js
+
+package certproof
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+)
+
+// fakeHelper is a child process that drains its stdin and then prints script's output,
+// standing in for a helper running in a user session the daemon cannot trust.
+func fakeHelper(t *testing.T, script string) *exec.Cmd {
+	t.Helper()
+	return exec.Command("/bin/sh", "-c", "cat >/dev/null; "+script)
+}
+
+func printJSON(t *testing.T, v any) string {
+	t.Helper()
+	out, err := json.Marshal(v)
+	require.NoError(t, err)
+	return fmt.Sprintf("printf '%%s' '%s'", out)
+}
+
+func TestRunHelperCmd_KeepsOnlyRequestedProofs(t *testing.T) {
+	req := HelperRequest{PeerKey: peerKey, Challenges: []HelperChallenge{{Nonce: []byte("asked")}}}
+	resp := HelperResponse{Proofs: []certposture.Proof{
+		{Nonce: []byte("injected"), Signature: []byte("x")},
+		{Nonce: []byte("asked"), Signature: []byte("first")},
+		{Nonce: []byte("asked"), Signature: []byte("second")},
+	}}
+
+	proofs, err := runHelperCmd(fakeHelper(t, printJSON(t, resp)), req)
+
+	require.NoError(t, err)
+	require.Len(t, proofs, 1, "a helper may not return more proofs than challenges or proofs for nonces it was not asked about")
+	assert.Equal(t, []byte("first"), proofs[0].Signature, "the first proof for the requested nonce is kept")
+}
+
+func TestRunHelperCmd_RejectsOversizedOutput(t *testing.T) {
+	req := HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}}
+	script := fmt.Sprintf("head -c %d /dev/zero", maxHelperStdout+1)
+
+	_, err := runHelperCmd(fakeHelper(t, script), req)
+
+	assert.ErrorIs(t, err, errHelperOutputTooLarge)
+}
+
+func TestRunHelperCmd_CapsStderrInError(t *testing.T) {
+	req := HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}}
+	script := fmt.Sprintf("head -c %d /dev/zero | tr '\\0' 'a' >&2; exit 3", 10*maxHelperStderr)
+
+	_, err := runHelperCmd(fakeHelper(t, script), req)
+
+	require.Error(t, err)
+	assert.LessOrEqual(t, len(err.Error()), maxHelperStderr+100, "a chatty helper must not blow up the daemon's error or log line")
+	assert.True(t, strings.Contains(err.Error(), "exit status 3"), "the exit status is kept: %v", err)
+}
+
+// TestRunHelperCmd_LogsStderrOfSuccessfulHelper covers a helper that answers but warns,
+// for one about a certificate it could not sign with: the warning reaches the daemon's
+// log, quoted so a helper cannot forge log lines with embedded newlines.
+func TestRunHelperCmd_LogsStderrOfSuccessfulHelper(t *testing.T) {
+	var logged bytes.Buffer
+	log.SetOutput(&logged)
+	level := log.GetLevel()
+	log.SetLevel(log.DebugLevel)
+	t.Cleanup(func() {
+		log.SetOutput(os.Stderr)
+		log.SetLevel(level)
+	})
+
+	req := HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}}
+	script := "printf 'failed signing certificate proof for CN=user\\nforged line\\n' >&2; " + printJSON(t, HelperResponse{})
+
+	_, err := runHelperCmd(fakeHelper(t, script), req)
+
+	require.NoError(t, err)
+	assert.Contains(t, logged.String(), "failed signing certificate proof for CN=user", "the helper's warning reaches the daemon log")
+	assert.NotContains(t, logged.String(), "\nforged line", "helper output cannot start a log line of its own")
+}
+
+// TestRunHelperCmd_KillsHelperBelowLauncher stands in for launchctl and sudo starting the
+// helper: the direct child spawns a grandchild that holds stdout and never exits, like a
+// helper waiting on a keychain prompt. The timeout must end both, not wait for the
+// grandchild.
+func TestRunHelperCmd_KillsHelperBelowLauncher(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, "/bin/sh", "-c", "sleep 30 & cat >/dev/null; wait")
+	killHelperGroupOnCancel(cmd)
+
+	start := time.Now()
+	_, err := runHelperCmd(cmd, HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}})
+
+	require.Error(t, err)
+	assert.Less(t, time.Since(start), 5*time.Second, "the helper is killed at the timeout, not awaited until it exits")
+}
+
+func TestRunHelperCmd_RejectsGarbage(t *testing.T) {
+	req := HelperRequest{Challenges: []HelperChallenge{{Nonce: []byte("asked")}}}
+
+	_, err := runHelperCmd(fakeHelper(t, "printf 'not json'"), req)
+
+	assert.ErrorContains(t, err, "decode helper response")
+}

client/internal/certproof/helper_spawn.go

@@ -0,0 +1,18 @@
+//go:build (darwin && !ios) || windows
+
+package certproof
+
+import (
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+func helperRequest(challenges []*proto.CertificateChallenge, peerKey []byte) HelperRequest {
+	req := HelperRequest{PeerKey: peerKey, Challenges: make([]HelperChallenge, 0, len(challenges))}
+	for _, challenge := range challenges {
+		req.Challenges = append(req.Challenges, HelperChallenge{
+			Nonce:          challenge.GetNonce(),
+			CACertificates: challenge.GetCaCertificates(),
+		})
+	}
+	return req
+}

client/internal/certproof/helper_spawn_test.go

@@ -0,0 +1,29 @@
+//go:build (darwin && !ios) || windows
+
+package certproof
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+func TestHelperRequest_CarriesEveryChallenge(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	challenges := []*proto.CertificateChallenge{
+		{Nonce: []byte("first"), CaCertificates: []string{ca.PEM}},
+		{Nonce: []byte("second")},
+	}
+
+	req := helperRequest(challenges, peerKey)
+
+	require.Len(t, req.Challenges, 2, "every challenge must reach the helper")
+	assert.Equal(t, peerKey, req.PeerKey, "the peer key binds the signature to this machine")
+	assert.Equal(t, []byte("first"), req.Challenges[0].Nonce, "the nonce must survive unchanged")
+	assert.Equal(t, []string{ca.PEM}, req.Challenges[0].CACertificates, "the accepted CAs must survive unchanged")
+	assert.Empty(t, req.Challenges[1].CACertificates, "a challenge without CAs stays without CAs")
+}

client/internal/certproof/helper_test.go

@@ -0,0 +1,66 @@
+package certproof
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+)
+
+// TestRunHelper_AnswersAChallengeFromItsStore runs the helper's request and response
+// handling in-process: the proof it writes verifies as the daemon will verify it. The
+// process boundary itself is covered by the runHelperCmd tests.
+func TestRunHelper_AnswersAChallengeFromItsStore(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	dir := storeDir(t)
+	key := certtest.ECDSAKey(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(ca.Issue(t, key, "device"))+certtest.KeyPEM(t, key))
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	nonce := challenger.Nonce(peerKey, time.Now())
+	request, err := json.Marshal(HelperRequest{
+		PeerKey:    peerKey,
+		Challenges: []HelperChallenge{{Nonce: nonce, CACertificates: []string{ca.PEM}}},
+	})
+	require.NoError(t, err, "request must encode")
+
+	var stdout bytes.Buffer
+	require.NoError(t, runHelper(context.Background(), newFileStore(dir), bytes.NewReader(request), &stdout))
+
+	var resp HelperResponse
+	require.NoError(t, json.Unmarshal(stdout.Bytes(), &resp), "helper must emit decodable JSON")
+	require.Len(t, resp.Proofs, 1, "the matching certificate should produce one proof")
+
+	// Verify exactly as management does, so the proof is proven to survive the encode,
+	// the process boundary and the decode intact.
+	chain, err := challenger.Verify(resp.Proofs[0], peerKey, time.Now())
+	require.NoError(t, err, "the decoded proof must verify against the issued nonce")
+	assert.Equal(t, "device", chain[0].Subject.CommonName, "the proven leaf should be the device certificate")
+}
+
+func TestRunHelper_NoChallengesYieldsEmptyResponse(t *testing.T) {
+	request, err := json.Marshal(HelperRequest{PeerKey: peerKey})
+	require.NoError(t, err)
+
+	var stdout bytes.Buffer
+	require.NoError(t, runHelper(context.Background(), newFileStore(storeDir(t)), bytes.NewReader(request), &stdout))
+
+	var resp HelperResponse
+	require.NoError(t, json.Unmarshal(stdout.Bytes(), &resp), "an empty request must still emit valid JSON")
+	assert.Empty(t, resp.Proofs, "no challenges should produce no proofs")
+}
+
+func TestRunHelper_RejectsMalformedRequest(t *testing.T) {
+	var stdout bytes.Buffer
+	err := runHelper(context.Background(), newFileStore(storeDir(t)), bytes.NewReader([]byte("not json")), &stdout)
+
+	require.Error(t, err, "a malformed request must fail rather than emit an empty proof set")
+	assert.Empty(t, stdout.String(), "nothing should be written to stdout on a decode failure")
+}

client/internal/certproof/keychain_darwin.go

@@ -0,0 +1,490 @@
+//go:build !ios
+
+package certproof
+
+import (
+	"bytes"
+	"context"
+	"crypto"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+	"unsafe"
+
+	"github.com/ebitengine/purego"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	securityFramework       = "/System/Library/Frameworks/Security.framework/Security"
+	coreFoundationFramework = "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation"
+
+	errSecItemNotFound          = -25300
+	errSecInteractionNotAllowed = -25308
+)
+
+// errKeyNeedsApproval reports a key whose access list does not include netbird, so using
+// it needs the user's approval, which a daemon has no UI to ask for.
+var errKeyNeedsApproval = errors.New("the key's access control requires user approval for netbird; " +
+	"import the identity with netbird allowed (security import <identity.p12> -k <keychain> " +
+	"-T /Applications/NetBird.app/Contents/MacOS/netbird), " +
+	"or set AllowAllAppsAccess in the MDM certificate payload, which allows every application")
+
+var (
+	keychainOnce sync.Once
+	keychainErr  error
+
+	secItemCopyMatching        func(query uintptr, result *uintptr) int32
+	secIdentityCopyCertificate func(identity uintptr, cert *uintptr) int32
+	secIdentityCopyPrivateKey  func(identity uintptr, key *uintptr) int32
+	secCertificateCopyData     func(cert uintptr) uintptr
+	secKeyCreateSignature      func(key, algorithm, data uintptr, err *uintptr) uintptr
+
+	secKeychainOpen           func(path *byte, keychain *uintptr) int32
+	secKeychainCopySearchList func(searchList *uintptr) int32
+	secKeychainGetPath        func(keychain uintptr, pathLength *uint32, path *byte) int32
+	cfArrayCreate             func(alloc uintptr, values *uintptr, count int, callBacks uintptr) uintptr
+
+	cfDictionaryCreate     func(alloc uintptr, keys, values *uintptr, count int, keyCallBacks, valueCallBacks uintptr) uintptr
+	cfArrayGetCount        func(array uintptr) int
+	cfArrayGetValueAtIndex func(array uintptr, index int) uintptr
+	cfDataCreate           func(alloc uintptr, data *byte, length int) uintptr
+	cfDataGetLength        func(data uintptr) int
+	cfDataGetBytePtr       func(data uintptr) unsafe.Pointer
+	cfErrorGetCode         func(err uintptr) int
+	cfRelease              func(ref uintptr)
+
+	kSecClass, kSecClassIdentity, kSecClassCertificate, kSecMatchLimit, kSecMatchLimitAll, kSecReturnRef  uintptr
+	kSecMatchSearchList                                                                                   uintptr
+	kSecKeyAlgorithmECDSASHA256, kSecKeyAlgorithmECDSASHA384, kSecKeyAlgorithmRSAPSSSHA256                uintptr
+	kCFBooleanTrue, kCFTypeDictionaryKeyCallBacks, kCFTypeDictionaryValueCallBacks, kCFTypeArrayCallBacks uintptr
+)
+
+// systemKeychain is where MDM installs device identities.
+const systemKeychain = "/Library/Keychains/System.keychain"
+
+// DefaultStore is the System keychain for the root daemon, so it never touches a user's
+// keychain, whose keys would ask for approval in a session the daemon has no UI in. Run
+// by an ordinary user, it is that user's keychain search list.
+func DefaultStore() Store {
+	if os.Geteuid() == 0 {
+		return newKeychainStore(systemKeychain)
+	}
+	return newKeychainStore()
+}
+
+// keychainStore yields the identities of a set of keychains, or of the process's keychain
+// search list when none is named, reached through purego so the client keeps building
+// with CGO_ENABLED=0.
+type keychainStore struct {
+	keychains []string
+}
+
+// newKeychainStore returns a store that searches the keychain files at paths, or the
+// process's keychain search list when no path is given.
+func newKeychainStore(paths ...string) *keychainStore {
+	return &keychainStore{keychains: paths}
+}
+
+func (s *keychainStore) Candidates(_ context.Context) ([]Candidate, error) {
+	if err := loadKeychain(); err != nil {
+		return nil, err
+	}
+	searchList, done, err := searchListOf(s.keychains)
+	if err != nil {
+		return nil, err
+	}
+	defer done()
+
+	var leaves []*x509.Certificate
+	err = eachIdentity(searchList, func(_ uintptr, der []byte) (bool, error) {
+		cert, err := x509.ParseCertificate(der)
+		if err != nil {
+			log.Warnf("skipping keychain identity: %v", err)
+			return false, nil
+		}
+		log.Debugf("keychain identity: subject=%q issuer=%q serial=%s expires=%s", cert.Subject, cert.Issuer, cert.SerialNumber, cert.NotAfter)
+		leaves = append(leaves, cert)
+		return false, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	// The certificate query runs even without identities: it separates a keychain that is
+	// readable but holds no identity from one the process cannot read at all.
+	pool, err := keychainCertificates(searchList)
+	if err != nil {
+		return nil, err
+	}
+	if len(leaves) == 0 {
+		log.Debugf("keychain search list holds no identities usable for certificate posture, but %d readable certificates: an identity needs its private key in the same keychain", len(pool))
+		return nil, nil
+	}
+	log.Debugf("keychain search list holds %d identities and %d certificates for chain building", len(leaves), len(pool))
+
+	candidates := make([]Candidate, 0, len(leaves))
+	for _, leaf := range leaves {
+		chain := buildChain(leaf, pool)
+		log.Debugf("keychain candidate %q issued by %q built a chain of %d certificates", leaf.Subject, leaf.Issuer, len(chain))
+		if len(chain) == 1 && leaf.CheckSignatureFrom(leaf) != nil {
+			log.Debugf("keychain candidate %q has no issuer in the keychain, its proof carries the leaf alone and only verifies if the challenge supplies %q", leaf.Subject, leaf.Issuer)
+		}
+		candidates = append(candidates, Candidate{Chain: chain, Signer: &keychainSigner{leaf: leaf, keychains: s.keychains}, Intermediates: pool})
+	}
+	return candidates, nil
+}
+
+// keychainSigner holds only the certificate; the identity is looked up again at signing
+// time so no keychain references outlive a call.
+type keychainSigner struct {
+	leaf      *x509.Certificate
+	keychains []string
+}
+
+func (s *keychainSigner) Public() crypto.PublicKey {
+	return s.leaf.PublicKey
+}
+
+func (s *keychainSigner) Sign(_ io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
+	scheme, err := schemeFor(s.leaf.PublicKey, opts)
+	if err != nil {
+		return nil, err
+	}
+	log.Debugf("signing certificate posture challenge with keychain key of %q", s.leaf.Subject)
+
+	searchList, done, err := searchListOf(s.keychains)
+	if err != nil {
+		return nil, err
+	}
+	defer done()
+
+	algorithm := keychainAlgorithm(scheme)
+	var signature []byte
+	var attempts signAttempts
+	err = eachIdentity(searchList, func(identity uintptr, der []byte) (bool, error) {
+		if !bytes.Equal(der, s.leaf.Raw) {
+			return false, nil
+		}
+		// The same certificate can sit in the keychain with more than one key, of which
+		// only one may be usable, so a failure moves on to the next match.
+		var ok bool
+		signature, ok = attempts.try(func() ([]byte, error) { return signWithIdentity(identity, algorithm, digest) })
+		return ok, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	if signature == nil {
+		if err := attempts.err(); err != nil {
+			return nil, err
+		}
+		return nil, errors.New("certificate is no longer in the keychain")
+	}
+	log.Debugf("keychain signed certificate posture challenge for %q, %d bytes", s.leaf.Subject, len(signature))
+	return signature, nil
+}
+
+func keychainAlgorithm(scheme sigScheme) uintptr {
+	switch scheme {
+	case schemeECDSASHA384:
+		return kSecKeyAlgorithmECDSASHA384
+	case schemeRSAPSSSHA256:
+		return kSecKeyAlgorithmRSAPSSSHA256
+	default:
+		return kSecKeyAlgorithmECDSASHA256
+	}
+}
+
+func signWithIdentity(identity, algorithm uintptr, digest []byte) ([]byte, error) {
+	var key uintptr
+	if status := secIdentityCopyPrivateKey(identity, &key); status != 0 {
+		return nil, fmt.Errorf("SecIdentityCopyPrivateKey: %d", status)
+	}
+	defer release(key)
+
+	data := cfDataCreate(0, &digest[0], len(digest))
+	if data == 0 {
+		return nil, errors.New("CFDataCreate returned NULL")
+	}
+	defer release(data)
+
+	var cfErr uintptr
+	signature := secKeyCreateSignature(key, algorithm, data, &cfErr)
+	if signature == 0 {
+		if cfErr == 0 {
+			return nil, errors.New("SecKeyCreateSignature failed without a CFError")
+		}
+		defer release(cfErr)
+		code := cfErrorGetCode(cfErr)
+		if code == errSecInteractionNotAllowed {
+			return nil, fmt.Errorf("SecKeyCreateSignature: CFError %d: %w", code, errKeyNeedsApproval)
+		}
+		return nil, fmt.Errorf("SecKeyCreateSignature: CFError %d", code)
+	}
+	defer release(signature)
+	return dataBytes(signature), nil
+}
+
+// searchListOf opens the keychain files at paths as a CFArray for kSecMatchSearchList,
+// or yields 0, the process's own search list, when paths is empty. The caller calls done
+// once it no longer uses the list.
+func searchListOf(paths []string) (searchList uintptr, done func(), err error) {
+	if len(paths) == 0 {
+		return 0, func() {}, nil
+	}
+	list, err := openSearchList(paths)
+	if err != nil {
+		return 0, nil, err
+	}
+	return list, func() { release(list) }, nil
+}
+
+// openSearchList opens the keychain files at paths, at least one, as a CFArray. The
+// caller releases the array.
+func openSearchList(paths []string) (uintptr, error) {
+	refs := make([]uintptr, 0, len(paths))
+	defer func() {
+		for _, ref := range refs {
+			release(ref)
+		}
+	}()
+	for _, path := range paths {
+		cpath := append([]byte(path), 0)
+		var keychain uintptr
+		if status := secKeychainOpen(&cpath[0], &keychain); status != 0 {
+			return 0, fmt.Errorf("SecKeychainOpen %s: %d", path, status)
+		}
+		refs = append(refs, keychain)
+	}
+	// The array retains the keychains, so the references opened here are released.
+	list := cfArrayCreate(0, &refs[0], len(refs), kCFTypeArrayCallBacks)
+	if list == 0 {
+		return 0, errors.New("CFArrayCreate returned NULL")
+	}
+	return list, nil
+}
+
+// eachIdentity calls fn with every identity in searchList, or in the process's search
+// list when it is 0, and its certificate. An identity whose certificate cannot be read is
+// skipped rather than ending the walk.
+func eachIdentity(searchList uintptr, fn func(identity uintptr, der []byte) (bool, error)) error {
+	return eachMatching(searchList, kSecClassIdentity, "identity", func(identity uintptr) (bool, error) {
+		var cert uintptr
+		if status := secIdentityCopyCertificate(identity, &cert); status != 0 {
+			log.Debugf("skipping keychain identity: SecIdentityCopyCertificate: %d", status)
+			return false, nil
+		}
+		der := certificateDER(cert)
+		release(cert)
+		if der == nil {
+			log.Debug("skipping keychain identity whose certificate has no DER data")
+			return false, nil
+		}
+		return fn(identity, der)
+	})
+}
+
+func keychainCertificates(searchList uintptr) ([]*x509.Certificate, error) {
+	var certs []*x509.Certificate
+	var unparsable int
+	err := eachMatching(searchList, kSecClassCertificate, "certificate", func(item uintptr) (bool, error) {
+		if cert, err := x509.ParseCertificate(certificateDER(item)); err == nil {
+			certs = append(certs, cert)
+			return false, nil
+		}
+		unparsable++
+		return false, nil
+	})
+	log.Debugf("keychain holds %d parsable certificates, %d unparsable", len(certs), unparsable)
+	return certs, err
+}
+
+func eachMatching(searchList, class uintptr, name string, fn func(item uintptr) (bool, error)) error {
+	keys := []uintptr{kSecClass, kSecMatchLimit, kSecReturnRef}
+	values := []uintptr{class, kSecMatchLimitAll, kCFBooleanTrue}
+	if searchList != 0 {
+		keys = append(keys, kSecMatchSearchList)
+		values = append(values, searchList)
+	}
+	query := cfDictionaryCreate(0, &keys[0], &values[0], len(keys), kCFTypeDictionaryKeyCallBacks, kCFTypeDictionaryValueCallBacks)
+	defer release(query)
+
+	var items uintptr
+	switch status := secItemCopyMatching(query, &items); status {
+	case 0:
+	case errSecItemNotFound:
+		log.Debugf("keychain %s query returned errSecItemNotFound (%d): the search list holds no item of this class", name, errSecItemNotFound)
+		return nil
+	default:
+		log.Debugf("keychain %s query returned OSStatus %d", name, status)
+		return fmt.Errorf("SecItemCopyMatching: %d", status)
+	}
+	defer release(items)
+
+	n := cfArrayGetCount(items)
+	log.Debugf("keychain %s query returned %d items", name, n)
+	for i := 0; i < n; i++ {
+		if stop, err := fn(cfArrayGetValueAtIndex(items, i)); stop || err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// certificateDER returns the DER form of cert, or nil when SecCertificateCopyData
+// returns NULL, which it does for an object that is not a valid certificate.
+func certificateDER(cert uintptr) []byte {
+	data := secCertificateCopyData(cert)
+	if data == 0 {
+		return nil
+	}
+	defer release(data)
+	return dataBytes(data)
+}
+
+func dataBytes(data uintptr) []byte {
+	n := cfDataGetLength(data)
+	if n <= 0 {
+		return nil
+	}
+	return bytes.Clone(unsafe.Slice((*byte)(cfDataGetBytePtr(data)), n))
+}
+
+// release drops a CoreFoundation reference. CFRelease crashes the process on NULL, and
+// several Security calls return NULL on failure, so every release goes through here.
+func release(ref uintptr) {
+	if ref != 0 {
+		cfRelease(ref)
+	}
+}
+
+func loadKeychain() error {
+	keychainOnce.Do(func() {
+		if keychainErr = resolveKeychain(); keychainErr != nil {
+			log.Debugf("macOS keychain unavailable for certificate posture: %v", keychainErr)
+			return
+		}
+		log.Debugf("macOS Security framework loaded for certificate posture, running as uid=%d euid=%d", os.Getuid(), os.Geteuid())
+		logSearchList()
+	})
+	return keychainErr
+}
+
+// logSearchList reports the keychains the process searches. The root daemon sees the
+// System keychain and System Roots, never a user's login keychain.
+func logSearchList() {
+	if secKeychainCopySearchList == nil || secKeychainGetPath == nil {
+		log.Debug("keychain search list diagnostics unavailable on this macOS version")
+		return
+	}
+
+	var list uintptr
+	if status := secKeychainCopySearchList(&list); status != 0 {
+		log.Debugf("SecKeychainCopySearchList returned OSStatus %d", status)
+		return
+	}
+	defer release(list)
+
+	n := cfArrayGetCount(list)
+	log.Debugf("keychain search list contains %d keychains", n)
+	for i := 0; i < n; i++ {
+		log.Debugf("keychain search list[%d]: %s", i, keychainPath(cfArrayGetValueAtIndex(list, i)))
+	}
+}
+
+func keychainPath(keychain uintptr) string {
+	path := make([]byte, 1024)
+	length := uint32(len(path))
+	if status := secKeychainGetPath(keychain, &length, &path[0]); status != 0 {
+		return fmt.Sprintf("<SecKeychainGetPath: %d>", status)
+	}
+	return string(path[:length])
+}
+
+func resolveKeychain() error {
+	security, err := purego.Dlopen(securityFramework, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+	if err != nil {
+		return fmt.Errorf("open %s: %w", securityFramework, err)
+	}
+	coreFoundation, err := purego.Dlopen(coreFoundationFramework, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+	if err != nil {
+		return fmt.Errorf("open %s: %w", coreFoundationFramework, err)
+	}
+
+	for _, fn := range []struct {
+		ptr  any
+		lib  uintptr
+		name string
+	}{
+		{&secItemCopyMatching, security, "SecItemCopyMatching"},
+		{&secIdentityCopyCertificate, security, "SecIdentityCopyCertificate"},
+		{&secIdentityCopyPrivateKey, security, "SecIdentityCopyPrivateKey"},
+		{&secCertificateCopyData, security, "SecCertificateCopyData"},
+		{&secKeyCreateSignature, security, "SecKeyCreateSignature"},
+		{&secKeychainOpen, security, "SecKeychainOpen"},
+		{&cfArrayCreate, coreFoundation, "CFArrayCreate"},
+		{&cfDictionaryCreate, coreFoundation, "CFDictionaryCreate"},
+		{&cfArrayGetCount, coreFoundation, "CFArrayGetCount"},
+		{&cfArrayGetValueAtIndex, coreFoundation, "CFArrayGetValueAtIndex"},
+		{&cfDataCreate, coreFoundation, "CFDataCreate"},
+		{&cfDataGetLength, coreFoundation, "CFDataGetLength"},
+		{&cfDataGetBytePtr, coreFoundation, "CFDataGetBytePtr"},
+		{&cfErrorGetCode, coreFoundation, "CFErrorGetCode"},
+		{&cfRelease, coreFoundation, "CFRelease"},
+	} {
+		symbol, err := purego.Dlsym(fn.lib, fn.name)
+		if err != nil {
+			return fmt.Errorf("resolve %s: %w", fn.name, err)
+		}
+		purego.RegisterFunc(fn.ptr, symbol)
+	}
+
+	for _, global := range []struct {
+		ptr   *uintptr
+		lib   uintptr
+		name  string
+		deref bool
+	}{
+		{&kSecClass, security, "kSecClass", true},
+		{&kSecClassIdentity, security, "kSecClassIdentity", true},
+		{&kSecClassCertificate, security, "kSecClassCertificate", true},
+		{&kSecMatchLimit, security, "kSecMatchLimit", true},
+		{&kSecMatchLimitAll, security, "kSecMatchLimitAll", true},
+		{&kSecReturnRef, security, "kSecReturnRef", true},
+		{&kSecMatchSearchList, security, "kSecMatchSearchList", true},
+		{&kSecKeyAlgorithmECDSASHA256, security, "kSecKeyAlgorithmECDSASignatureDigestX962SHA256", true},
+		{&kSecKeyAlgorithmECDSASHA384, security, "kSecKeyAlgorithmECDSASignatureDigestX962SHA384", true},
+		{&kSecKeyAlgorithmRSAPSSSHA256, security, "kSecKeyAlgorithmRSASignatureDigestPSSSHA256", true},
+		{&kCFBooleanTrue, coreFoundation, "kCFBooleanTrue", true},
+		{&kCFTypeDictionaryKeyCallBacks, coreFoundation, "kCFTypeDictionaryKeyCallBacks", false},
+		{&kCFTypeDictionaryValueCallBacks, coreFoundation, "kCFTypeDictionaryValueCallBacks", false},
+		{&kCFTypeArrayCallBacks, coreFoundation, "kCFTypeArrayCallBacks", false},
+	} {
+		addr, err := purego.Dlsym(global.lib, global.name)
+		if err != nil {
+			return fmt.Errorf("resolve %s: %w", global.name, err)
+		}
+		if global.deref {
+			addr = **(**uintptr)(unsafe.Pointer(&addr))
+		}
+		*global.ptr = addr
+	}
+
+	resolveOptional(security, "SecKeychainCopySearchList", &secKeychainCopySearchList)
+	resolveOptional(security, "SecKeychainGetPath", &secKeychainGetPath)
+	return nil
+}
+
+// resolveOptional binds a diagnostic-only symbol, leaving it nil when the framework no
+// longer exports it so keychain lookups keep working without it.
+func resolveOptional(lib uintptr, name string, ptr any) {
+	symbol, err := purego.Dlsym(lib, name)
+	if err != nil {
+		log.Debugf("keychain diagnostics: %s unavailable: %v", name, err)
+		return
+	}
+	purego.RegisterFunc(ptr, symbol)
+}

client/internal/certproof/keystore.go

@@ -0,0 +1,77 @@
+package certproof
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"fmt"
+	"math/big"
+	"slices"
+)
+
+var errUnsupportedScheme = errors.New("unsupported signature scheme for OS keystore")
+
+type sigScheme int
+
+const (
+	schemeECDSASHA256 sigScheme = iota + 1
+	schemeECDSASHA384
+	schemeRSAPSSSHA256
+)
+
+// schemeFor maps a crypto.Signer request onto the schemes the OS keystores perform.
+func schemeFor(pub crypto.PublicKey, opts crypto.SignerOpts) (sigScheme, error) {
+	switch pub.(type) {
+	case *ecdsa.PublicKey:
+		switch opts.HashFunc() {
+		case crypto.SHA256:
+			return schemeECDSASHA256, nil
+		case crypto.SHA384:
+			return schemeECDSASHA384, nil
+		}
+	case *rsa.PublicKey:
+		if pss, ok := opts.(*rsa.PSSOptions); ok && pss.Hash == crypto.SHA256 {
+			return schemeRSAPSSSHA256, nil
+		}
+	}
+	return 0, fmt.Errorf("%w: %T with %v", errUnsupportedScheme, pub, opts.HashFunc())
+}
+
+// buildChain extends leaf with the issuers found in pool up to a self-signed certificate.
+func buildChain(leaf *x509.Certificate, pool []*x509.Certificate) []*x509.Certificate {
+	chain := []*x509.Certificate{leaf}
+	current := leaf
+	for current.CheckSignatureFrom(current) != nil {
+		issuer := issuerIn(current, pool, chain)
+		if issuer == nil {
+			break
+		}
+		chain = append(chain, issuer)
+		current = issuer
+	}
+	return chain
+}
+
+func issuerIn(cert *x509.Certificate, pool, seen []*x509.Certificate) *x509.Certificate {
+	for _, candidate := range pool {
+		if slices.ContainsFunc(seen, candidate.Equal) {
+			continue
+		}
+		if cert.CheckSignatureFrom(candidate) == nil {
+			return candidate
+		}
+	}
+	return nil
+}
+
+// ecdsaSignatureASN1 converts the fixed-width r||s form emitted by CNG into the DER form Go verifies.
+func ecdsaSignatureASN1(raw []byte) ([]byte, error) {
+	if len(raw) == 0 || len(raw)%2 != 0 {
+		return nil, errors.New("malformed raw ECDSA signature")
+	}
+	half := len(raw) / 2
+	return asn1.Marshal(struct{ R, S *big.Int }{new(big.Int).SetBytes(raw[:half]), new(big.Int).SetBytes(raw[half:])})
+}

client/internal/certproof/keystore_test.go

@@ -0,0 +1,91 @@
+package certproof
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+)
+
+func TestBuildChain_FollowsIssuersThroughThePool(t *testing.T) {
+	root := certtest.NewCA(t, "root")
+	intermediate := certtest.NewIntermediate(t, root, "intermediate")
+	unrelated := certtest.NewCA(t, "unrelated")
+	leaf := intermediate.Issue(t, certtest.ECDSAKey(t), "device")
+	pool := []*x509.Certificate{unrelated.Cert, root.Cert, leaf, intermediate.Cert}
+
+	chain := buildChain(leaf, pool)
+
+	require.Equal(t, []*x509.Certificate{leaf, intermediate.Cert, root.Cert}, chain)
+	roots, err := certposture.ParseCAs([]string{root.PEM})
+	require.NoError(t, err)
+	assert.NoError(t, certposture.VerifyChain(chain, roots, time.Now()))
+}
+
+func TestBuildChain_StopsWhereThePoolEnds(t *testing.T) {
+	root := certtest.NewCA(t, "root")
+	intermediate := certtest.NewIntermediate(t, root, "intermediate")
+	leaf := intermediate.Issue(t, certtest.ECDSAKey(t), "device")
+
+	assert.Equal(t, []*x509.Certificate{leaf}, buildChain(leaf, nil))
+	assert.Equal(t, []*x509.Certificate{leaf, intermediate.Cert}, buildChain(leaf, []*x509.Certificate{intermediate.Cert}))
+}
+
+func TestSchemeFor(t *testing.T) {
+	ecKey := certtest.ECDSAKey(t)
+	rsaKey := certtest.RSAKey(t)
+	pss := &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash, Hash: crypto.SHA256}
+
+	tests := []struct {
+		name string
+		pub  crypto.PublicKey
+		opts crypto.SignerOpts
+		want sigScheme
+	}{
+		{"ecdsa sha256", ecKey.Public(), crypto.SHA256, schemeECDSASHA256},
+		{"ecdsa sha384", ecKey.Public(), crypto.SHA384, schemeECDSASHA384},
+		{"rsa pss sha256", rsaKey.Public(), pss, schemeRSAPSSSHA256},
+		{"rsa pkcs1v15", rsaKey.Public(), crypto.SHA256, 0},
+		{"ecdsa sha512", ecKey.Public(), crypto.SHA512, 0},
+		{"rsa pss sha384", rsaKey.Public(), &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash, Hash: crypto.SHA384}, 0},
+		{"ed25519", certtest.Ed25519Key(t).Public(), crypto.Hash(0), 0},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := schemeFor(tc.pub, tc.opts)
+			if tc.want == 0 {
+				assert.ErrorIs(t, err, errUnsupportedScheme)
+				return
+			}
+			require.NoError(t, err)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}
+
+func TestECDSASignatureASN1(t *testing.T) {
+	key := certtest.ECDSAKey(t).(*ecdsa.PrivateKey)
+	digest := sha256.Sum256([]byte("nonce"))
+	r, s, err := ecdsa.Sign(rand.Reader, key, digest[:])
+	require.NoError(t, err)
+	raw := append(r.FillBytes(make([]byte, 32)), s.FillBytes(make([]byte, 32))...)
+
+	der, err := ecdsaSignatureASN1(raw)
+	require.NoError(t, err)
+	assert.True(t, ecdsa.VerifyASN1(&key.PublicKey, digest[:], der))
+
+	_, err = ecdsaSignatureASN1(raw[:63])
+	assert.Error(t, err, "an odd length cannot split into r and s")
+	_, err = ecdsaSignatureASN1(nil)
+	assert.Error(t, err, "an empty signature is malformed")
+}

client/internal/certproof/merge.go

@@ -0,0 +1,50 @@
+package certproof
+
+import (
+	"crypto/sha256"
+	"crypto/x509"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+)
+
+// mergeProofs appends the user session proofs to the device proofs, dropping one whose
+// chain the device already proved. Management checks each chain against each check's CAs,
+// so the same leaf proven through another chain is kept.
+func mergeProofs(device, user []certposture.Proof) []certposture.Proof {
+	if len(user) == 0 {
+		return device
+	}
+
+	seen := make(map[[sha256.Size]byte]struct{}, len(device)+len(user))
+	for _, proof := range device {
+		if len(proof.Chain) > 0 {
+			seen[chainDERFingerprint(proof.Chain)] = struct{}{}
+		}
+	}
+
+	merged := device
+	for _, proof := range user {
+		if len(proof.Chain) == 0 {
+			continue
+		}
+		fingerprint := chainDERFingerprint(proof.Chain)
+		if _, done := seen[fingerprint]; done {
+			continue
+		}
+		seen[fingerprint] = struct{}{}
+		merged = append(merged, proof)
+		logUserProof(proof)
+	}
+	return merged
+}
+
+func logUserProof(proof certposture.Proof) {
+	leaf, err := x509.ParseCertificate(proof.Chain[0])
+	if err != nil {
+		log.Debugf("certificate posture: user proof carries an unparsable leaf: %v", err)
+		return
+	}
+	log.Debugf("certificate posture: signed-in user proved %q issued by %q", leaf.Subject, leaf.Issuer)
+}

client/internal/certproof/merge_test.go

@@ -0,0 +1,54 @@
+package certproof
+
+import (
+	"crypto/sha256"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+)
+
+func TestMergeProofs_ProvesACertificateHeldByBothStoresOnce(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	shared := ca.Issue(t, certtest.ECDSAKey(t), "shared")
+	userOnly := ca.Issue(t, certtest.ECDSAKey(t), "user-only")
+
+	device := []certposture.Proof{{Chain: [][]byte{shared.Raw}}}
+	user := []certposture.Proof{{Chain: [][]byte{shared.Raw}}, {Chain: [][]byte{userOnly.Raw}}, {}}
+
+	merged := mergeProofs(device, user)
+
+	require.Len(t, merged, 2, "the shared leaf is proven once and the empty chain is dropped")
+	assert.Equal(t, shared.Raw, merged[0].Chain[0], "the device proof keeps its place")
+	assert.Equal(t, userOnly.Raw, merged[1].Chain[0], "the user-only certificate is appended")
+}
+
+func TestMergeProofs_KeepsDeviceProofsWhenNoUserSession(t *testing.T) {
+	ca := certtest.NewCA(t, "corp-root")
+	device := []certposture.Proof{{Chain: [][]byte{ca.Issue(t, certtest.ECDSAKey(t), "device").Raw}}}
+
+	merged := mergeProofs(device, nil)
+
+	require.Len(t, merged, 1, "a machine with nobody signed in still sends its device proof")
+	assert.Equal(t, sha256.Sum256(device[0].Chain[0]), sha256.Sum256(merged[0].Chain[0]), "the device proof is unchanged")
+}
+
+func TestMergeProofs_KeepsAnotherChainOfTheSameLeaf(t *testing.T) {
+	root := certtest.NewCA(t, "corp-root")
+	interA := root.Issue(t, certtest.ECDSAKey(t), "inter-a")
+	interB := root.Issue(t, certtest.ECDSAKey(t), "inter-b")
+	leaf := root.Issue(t, certtest.ECDSAKey(t), "leaf")
+
+	// Management checks each chain against each check's CAs, so the same leaf proven
+	// through another chain is a different proof, not a duplicate.
+	device := []certposture.Proof{{Chain: [][]byte{leaf.Raw, interA.Raw}}}
+	user := []certposture.Proof{{Chain: [][]byte{leaf.Raw, interB.Raw}}, {Chain: [][]byte{leaf.Raw, interA.Raw}}}
+
+	merged := mergeProofs(device, user)
+
+	require.Len(t, merged, 2, "the chain only the user store holds is kept, the one both hold is not repeated")
+	assert.Equal(t, interB.Raw, merged[1].Chain[1], "the user's chain through the other intermediate is appended")
+}

client/internal/certproof/pinlatch.go

@@ -0,0 +1,54 @@
+package certproof
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"sync"
+)
+
+// errPINRejectedBefore is returned instead of logging in with a PIN the token already
+// refused: every failed login counts towards the token's lockout, which for a TPM is
+// shared with everything else on the machine, and proofs are collected on every sync.
+var errPINRejectedBefore = errors.New("PKCS#11 token rejected this PIN before, not trying it again")
+
+// errPINNeedsToken refuses a PIN that names no token to log in to.
+var errPINNeedsToken = errors.New("a PKCS#11 PIN needs the token named in NB_CERT_PKCS11_URI, as token=<label>")
+
+// rejectedPINs outlives a single store, since a store is built for each collection.
+var rejectedPINs = &pinLatch{keys: map[[sha256.Size]byte]struct{}{}}
+
+// pinLoginMu serializes logging in to a PKCS#11 token with a PIN, from checking the latch
+// to recording a rejection.
+var pinLoginMu sync.Mutex
+
+// pinLatch remembers PINs a token rejected. Keys are hashes, so the PIN itself is not
+// kept in memory any longer than the store that read it.
+type pinLatch struct {
+	mu   sync.Mutex
+	keys map[[sha256.Size]byte]struct{}
+}
+
+func (l *pinLatch) has(key [sha256.Size]byte) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	_, ok := l.keys[key]
+	return ok
+}
+
+func (l *pinLatch) add(key [sha256.Size]byte) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.keys[key] = struct{}{}
+}
+
+// rejectedPINKey identifies a PIN for one token of one module, so a PIN another token
+// rejected is still tried on the token it belongs to.
+func rejectedPINKey(module, token string, pin []byte) [sha256.Size]byte {
+	var buf []byte
+	for _, part := range [][]byte{[]byte(module), []byte(token), pin} {
+		buf = binary.BigEndian.AppendUint64(buf, uint64(len(part)))
+		buf = append(buf, part...)
+	}
+	return sha256.Sum256(buf)
+}

client/internal/certproof/pinlatch_test.go

@@ -0,0 +1,29 @@
+package certproof
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRejectedPINKey_ScopesToModuleTokenAndPIN(t *testing.T) {
+	base := rejectedPINKey("/lib/a.so", "netbird", []byte("1234"))
+
+	assert.Equal(t, base, rejectedPINKey("/lib/a.so", "netbird", []byte("1234")), "the same PIN on the same token is the same key")
+	assert.NotEqual(t, base, rejectedPINKey("/lib/a.so", "netbird", []byte("4321")), "a corrected PIN must be tried")
+	assert.NotEqual(t, base, rejectedPINKey("/lib/a.so", "piv", []byte("1234")), "a PIN rejected by one token is still tried on another")
+	assert.NotEqual(t, base, rejectedPINKey("/lib/b.so", "netbird", []byte("1234")), "a PIN rejected through one module is still tried through another")
+	assert.NotEqual(t, rejectedPINKey("ab", "", []byte("1")), rejectedPINKey("a", "b", []byte("1")),
+		"field boundaries are part of the key, so shifted fields do not collide")
+}
+
+func TestPINLatch_RemembersRejectedKeys(t *testing.T) {
+	latch := &pinLatch{keys: map[[32]byte]struct{}{}}
+	rejected := rejectedPINKey("/lib/a.so", "netbird", []byte("0000"))
+	other := rejectedPINKey("/lib/a.so", "netbird", []byte("1234"))
+
+	assert.False(t, latch.has(rejected), "nothing is rejected before a login fails")
+	latch.add(rejected)
+	assert.True(t, latch.has(rejected), "a rejected PIN is not tried again")
+	assert.False(t, latch.has(other), "other PINs are unaffected")
+}

client/internal/certproof/pkcs11store.go

@@ -0,0 +1,342 @@
+package certproof
+
+import (
+	"context"
+	"crypto"
+	"crypto/sha256"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/pkcs11"
+)
+
+const (
+	// PINEnv carries the user PIN of the PKCS#11 token. It is read from the daemon's
+	// environment only, so the PIN never lands in the profile config or on a command line.
+	PINEnv = "NB_TPM_PIN"
+	// PKCS11URIEnv carries the RFC 7512 URI of the token. Like the PIN it lives in the
+	// daemon's environment rather than the profile config, since it may carry pin-value.
+	PKCS11URIEnv = "NB_CERT_PKCS11_URI"
+)
+
+// PKCS11Config names the token whose certificates the store yields. URI is an RFC 7512
+// PKCS#11 URI, or empty for the first token the p11-kit proxy exposes. PIN is the user
+// PIN, and takes precedence over a pin-value or pin-source the URI carries.
+type PKCS11Config struct {
+	URI string
+	PIN string
+}
+
+// PKCS11FromEnv returns the token named by NB_CERT_PKCS11_URI with the PIN set in
+// NB_TPM_PIN, either empty when unset.
+func PKCS11FromEnv() PKCS11Config {
+	return PKCS11Config{URI: os.Getenv(PKCS11URIEnv), PIN: os.Getenv(PINEnv)}
+}
+
+// pkcs11Store yields the identities of a PKCS#11 token, which is how tpm2-pkcs11 exposes
+// TPM-held keys on Linux. Certificates on the token are paired with keys by CKA_ID, the
+// convention tpm2_ptool addcert and pkcs11-tool follow; certificate files in the PEM
+// directory by public key. Every signature happens on the token.
+type pkcs11Store struct {
+	uri     *pkcs11.URI
+	pin     string
+	certDir string
+}
+
+// newPKCS11Store parses cfg.URI, standing in the bare defaults when it is empty. Files in
+// certDir without a key of their own are paired with the token's keys by public key.
+//
+// A PIN is only accepted together with a token label: without one the PIN would go to
+// whichever token the module lists first, which on a machine with a smartcard plugged
+// in may be the card, and every wrong PIN counts towards that card's lockout.
+func newPKCS11Store(cfg PKCS11Config, certDir string) (*pkcs11Store, error) {
+	store := &pkcs11Store{uri: &pkcs11.URI{}, pin: cfg.PIN, certDir: certDir}
+	if cfg.URI != "" {
+		parsed, err := pkcs11.ParseURI(cfg.URI)
+		if err != nil {
+			return nil, err
+		}
+		store.uri = parsed
+	}
+	if (cfg.PIN != "" || store.uri.HasPIN()) && store.uri.Token == "" {
+		return nil, errPINNeedsToken
+	}
+	return store, nil
+}
+
+func (s *pkcs11Store) Candidates(_ context.Context) ([]Candidate, error) {
+	session, err := s.open()
+	if err != nil {
+		return nil, err
+	}
+	defer session.Close()
+
+	certs, err := tokenCertificates(session)
+	if err != nil {
+		return nil, err
+	}
+	fileChains, fileIntermediates, err := s.fileChains()
+	if err != nil {
+		return nil, err
+	}
+	log.Debugf("%s holds %d certificates, %d certificate files without a key wait for its keys", s, len(certs), len(fileChains))
+
+	pool := make([]*x509.Certificate, 0, len(certs))
+	for _, cert := range certs {
+		pool = append(pool, cert.cert)
+	}
+	for _, chain := range fileChains {
+		pool = append(pool, chain...)
+	}
+	pool = append(pool, fileIntermediates...)
+
+	var candidates []Candidate
+	for _, cert := range certs {
+		if _, err := privateKey(session, cert.id); err != nil {
+			log.Debugf("%s certificate %q has no usable private key: %v", s, cert.cert.Subject, err)
+			continue
+		}
+		candidates = append(candidates, s.candidate(cert.cert, cert.id, pool))
+	}
+	if len(fileChains) == 0 {
+		return candidates, nil
+	}
+
+	// A token that cannot list its public keys still answers for the certificates it
+	// holds, so the identities found above are kept.
+	keys, err := tokenPublicKeys(session)
+	if err != nil {
+		log.Warnf("%s: cannot read its public keys, certificate files are not paired with them: %v", s, err)
+		return candidates, nil
+	}
+	for _, chain := range fileChains {
+		leaf := chain[0]
+		id, ok := keys.idFor(leaf.PublicKey)
+		if !ok {
+			log.Debugf("%s holds no key for certificate %q from %s", s, leaf.Subject, s.certDir)
+			continue
+		}
+		candidates = append(candidates, s.candidate(leaf, id, pool))
+	}
+	return candidates, nil
+}
+
+func (s *pkcs11Store) candidate(leaf *x509.Certificate, id []byte, pool []*x509.Certificate) Candidate {
+	chain := buildChain(leaf, pool)
+	log.Debugf("%s candidate %q issued by %q built a chain of %d certificates", s, leaf.Subject, leaf.Issuer, len(chain))
+	return Candidate{Chain: chain, Signer: &pkcs11Signer{store: s, leaf: leaf, id: id}, Intermediates: pool}
+}
+
+// fileChains reads the certificate files in the PEM directory that carry no key of their
+// own; the file store answers for the ones that do. The certificates of a file that does
+// carry a key are returned too, since they can complete the chain of a token certificate.
+func (s *pkcs11Store) fileChains() (chains [][]*x509.Certificate, intermediates []*x509.Certificate, err error) {
+	if s.certDir == "" {
+		return nil, nil, nil
+	}
+	paths, err := certFiles(s.certDir)
+	if err != nil {
+		return nil, nil, err
+	}
+	for _, path := range paths {
+		chain, signer, err := loadPEM(path)
+		if err != nil {
+			continue
+		}
+		if signer != nil {
+			intermediates = append(intermediates, chain...)
+			continue
+		}
+		chains = append(chains, chain)
+	}
+	return chains, intermediates, nil
+}
+
+func (s *pkcs11Store) String() string {
+	if s.uri.Token == "" {
+		return "PKCS#11 token"
+	}
+	return fmt.Sprintf("PKCS#11 token %q", s.uri.Token)
+}
+
+func (s *pkcs11Store) open() (*pkcs11.Session, error) {
+	module, err := pkcs11.Load(s.uri.Module())
+	if err != nil {
+		return nil, err
+	}
+	pin, err := s.userPIN()
+	if err != nil {
+		return nil, err
+	}
+	if pin == nil {
+		return module.OpenSession(s.uri.Token, nil)
+	}
+
+	// The check, the login and recording a rejection happen under one lock, so two
+	// collections running at once cannot both send a PIN the token is about to refuse.
+	pinLoginMu.Lock()
+	defer pinLoginMu.Unlock()
+	key := rejectedPINKey(s.uri.Module(), s.uri.Token, pin)
+	if rejectedPINs.has(key) {
+		return nil, errPINRejectedBefore
+	}
+	session, err := module.OpenSession(s.uri.Token, pin)
+	if pkcs11.PINRejected(err) {
+		rejectedPINs.add(key)
+		return nil, fmt.Errorf("%s rejected the PIN, not retrying it until the daemon restarts: %w", s, err)
+	}
+	return session, err
+}
+
+func (s *pkcs11Store) userPIN() ([]byte, error) {
+	if s.pin != "" {
+		return []byte(s.pin), nil
+	}
+	return s.uri.PIN()
+}
+
+type tokenKey struct {
+	id     []byte
+	public crypto.PublicKey
+}
+
+type tokenKeys []tokenKey
+
+func tokenPublicKeys(session *pkcs11.Session) (tokenKeys, error) {
+	objects, err := session.FindObjects(pkcs11.Attribute{Type: pkcs11.AttrClass, Value: pkcs11.ULong(pkcs11.ClassPublicKey)})
+	if err != nil {
+		return nil, err
+	}
+	keys := make(tokenKeys, 0, len(objects))
+	for _, object := range objects {
+		id, err := session.Attribute(object, pkcs11.AttrID)
+		if err != nil {
+			log.Debugf("skipping public key on PKCS#11 token: %v", err)
+			continue
+		}
+		public, err := session.PublicKey(object)
+		if err != nil {
+			log.Debugf("skipping public key on PKCS#11 token: %v", err)
+			continue
+		}
+		keys = append(keys, tokenKey{id: id, public: public})
+	}
+	return keys, nil
+}
+
+// idFor finds the token key whose public half is pub, so a certificate kept outside the
+// token is still signed for by the key inside it.
+func (k tokenKeys) idFor(pub crypto.PublicKey) ([]byte, bool) {
+	for _, key := range k {
+		equaler, ok := key.public.(interface{ Equal(crypto.PublicKey) bool })
+		if ok && len(key.id) > 0 && equaler.Equal(pub) {
+			return key.id, true
+		}
+	}
+	return nil, false
+}
+
+type tokenCertificate struct {
+	cert *x509.Certificate
+	id   []byte
+}
+
+func tokenCertificates(session *pkcs11.Session) ([]tokenCertificate, error) {
+	objects, err := session.FindObjects(
+		pkcs11.Attribute{Type: pkcs11.AttrClass, Value: pkcs11.ULong(pkcs11.ClassCertificate)},
+		pkcs11.Attribute{Type: pkcs11.AttrCertificateType, Value: pkcs11.ULong(pkcs11.CertificateX509)},
+	)
+	if err != nil {
+		return nil, err
+	}
+	certs := make([]tokenCertificate, 0, len(objects))
+	for _, object := range objects {
+		der, err := session.Attribute(object, pkcs11.AttrValue)
+		if err != nil {
+			return nil, err
+		}
+		cert, err := x509.ParseCertificate(der)
+		if err != nil {
+			log.Warnf("skipping unparsable certificate on PKCS#11 token: %v", err)
+			continue
+		}
+		id, err := session.Attribute(object, pkcs11.AttrID)
+		if err != nil {
+			return nil, err
+		}
+		certs = append(certs, tokenCertificate{cert: cert, id: id})
+	}
+	return certs, nil
+}
+
+var errNoPrivateKey = errors.New("no private key shares the certificate's CKA_ID")
+
+func privateKey(session *pkcs11.Session, id []byte) (pkcs11.Object, error) {
+	if len(id) == 0 {
+		return 0, errNoPrivateKey
+	}
+	keys, err := session.FindObjects(
+		pkcs11.Attribute{Type: pkcs11.AttrClass, Value: pkcs11.ULong(pkcs11.ClassPrivateKey)},
+		pkcs11.Attribute{Type: pkcs11.AttrID, Value: id},
+	)
+	if err != nil {
+		return 0, err
+	}
+	if len(keys) == 0 {
+		return 0, errNoPrivateKey
+	}
+	return keys[0], nil
+}
+
+// pkcs11Signer holds only the certificate and its CKA_ID; the key is looked up in a fresh
+// session at signing time so no token handle outlives a call.
+type pkcs11Signer struct {
+	store *pkcs11Store
+	leaf  *x509.Certificate
+	id    []byte
+}
+
+func (s *pkcs11Signer) Public() crypto.PublicKey {
+	return s.leaf.PublicKey
+}
+
+func (s *pkcs11Signer) Sign(_ io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
+	scheme, err := schemeFor(s.leaf.PublicKey, opts)
+	if err != nil {
+		return nil, err
+	}
+	session, err := s.store.open()
+	if err != nil {
+		return nil, err
+	}
+	defer session.Close()
+
+	key, err := privateKey(session, s.id)
+	if err != nil {
+		return nil, err
+	}
+	signature, err := session.Sign(pkcs11Mechanism(scheme), key, digest)
+	if err != nil {
+		return nil, err
+	}
+	if scheme == schemeRSAPSSSHA256 {
+		return signature, nil
+	}
+	return ecdsaSignatureASN1(signature)
+}
+
+// pkcs11Mechanism maps a signature scheme onto the token mechanism that consumes a digest.
+func pkcs11Mechanism(scheme sigScheme) pkcs11.Mechanism {
+	if scheme == schemeRSAPSSSHA256 {
+		return pkcs11.Mechanism{
+			Type: pkcs11.MechRSAPKCSPSS,
+			PSS:  &pkcs11.PSSParams{Hash: pkcs11.MechSHA256, MGF: pkcs11.MGF1SHA256, SaltLen: sha256.Size},
+		}
+	}
+	return pkcs11.Mechanism{Type: pkcs11.MechECDSA}
+}

client/internal/certproof/pkcs11store_test.go

@@ -0,0 +1,407 @@
+package certproof
+
+import (
+	"context"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"math/big"
+	"os"
+	"runtime"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/pkcs11"
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+const (
+	testPKCS11URIEnv = "NB_TEST_PKCS11_URI"
+	// testPKCS11DisposableEnv marks the token as disposable, allowing tests that spend
+	// attempts of its PIN lockout counter.
+	testPKCS11DisposableEnv = "NB_TEST_PKCS11_DISPOSABLE"
+)
+
+type failingStore struct{}
+
+func (failingStore) Candidates(context.Context) ([]Candidate, error) {
+	return nil, errors.New("token unplugged")
+}
+
+func TestStores_KeepsFileCertificatesWhenTokenFails(t *testing.T) {
+	ca := certtest.NewCA(t, "corp")
+	key := certtest.ECDSAKey(t)
+	dir := storeDir(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(ca.Issue(t, key, "device"))+certtest.KeyPEM(t, key))
+
+	candidates, err := Stores{failingStore{}, newFileStore(dir)}.Candidates(context.Background())
+	require.NoError(t, err)
+	assert.Len(t, candidates, 1, "the directory's certificate must survive a failing token")
+}
+
+// TestCollect_PKCS11TokenEndToEnd needs an initialised token with a user PIN, named by
+// NB_TEST_PKCS11_URI. With SoftHSM:
+//
+//	softhsm2-util --init-token --free --label netbird --pin 1234 --so-pin 1234
+//	NB_TEST_PKCS11_URI='pkcs11:token=netbird?module-path=/usr/lib/softhsm/libsofthsm2.so&pin-value=1234' \
+//	  go test -tags pkcs11 ./client/internal/certproof/ -run PKCS11 -v
+//
+// It imports a key and its certificate as token objects, then proves the certificate
+// through the store the way the daemon would. Every run adds one more identity to the token.
+func TestCollect_PKCS11TokenEndToEnd(t *testing.T) {
+	store, uri := pkcs11TestStore(t, "")
+
+	keys := map[string]crypto.Signer{"ecdsa": certtest.ECDSAKey(t), "rsa": certtest.RSAKey(t)}
+	for name, key := range keys {
+		t.Run(name, func(t *testing.T) {
+			ca := certtest.NewCA(t, "corp-"+name)
+			leaf := ca.Issue(t, key, "device-"+name)
+			importIdentity(t, uri, key, leaf)
+
+			challenger := certposture.NewChallenger([]byte("secret"))
+			now := time.Now()
+			nonce := challenger.Nonce(peerKey, now)
+			checks := []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{Nonce: nonce, CaCertificates: []string{ca.PEM}}}}
+
+			proofs := Collect(context.Background(), store, checks, peerKey)
+			require.Len(t, proofs, 1, "the token-held key must prove exactly this run's certificate")
+			chain, err := challenger.Verify(proofs[0], peerKey, now)
+			require.NoError(t, err)
+			assert.True(t, leaf.Equal(chain[0]), "proof must carry the imported certificate")
+		})
+	}
+}
+
+// Attribute types the import needs and the store does not.
+const (
+	attrPrivate         = 0x2
+	attrIssuer          = 0x81
+	attrSerialNumber    = 0x82
+	attrSensitive       = 0x103
+	attrSign            = 0x108
+	attrVerify          = 0x10a
+	attrPrivateExponent = 0x123
+	attrPrime1          = 0x124
+	attrPrime2          = 0x125
+	attrExponent1       = 0x126
+	attrExponent2       = 0x127
+	attrCoefficient     = 0x128
+)
+
+var (
+	ckTrue  = []byte{1}
+	ckFalse = []byte{0}
+	// The P-256 named curve OID in DER, which is what CKA_EC_PARAMS carries.
+	oidP256 = []byte{0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07}
+)
+
+// importIdentity stores key and leaf on the token the way tpm2_ptool import and addcert
+// do: private and public key objects plus the certificate, all under one CKA_ID.
+func importIdentity(t *testing.T, uri string, key crypto.Signer, leaf *x509.Certificate) {
+	t.Helper()
+	id := importKey(t, uri, key, leaf.Subject.CommonName)
+	importCertificate(t, uri, leaf, id)
+}
+
+func importKey(t *testing.T, uri string, key crypto.Signer, label string) []byte {
+	t.Helper()
+	session := readWriteSession(t, uri)
+	defer session.Close()
+
+	id := make([]byte, 8)
+	_, err := rand.Read(id)
+	require.NoError(t, err)
+
+	private := []pkcs11.Attribute{
+		attr(pkcs11.AttrClass, pkcs11.ULong(pkcs11.ClassPrivateKey)),
+		attr(pkcs11.AttrToken, ckTrue),
+		attr(attrPrivate, ckTrue),
+		attr(attrSensitive, ckTrue),
+		attr(attrSign, ckTrue),
+		attr(pkcs11.AttrLabel, []byte(label)),
+		attr(pkcs11.AttrID, id),
+	}
+	_, err = session.CreateObject(append(private, privateKeyAttributes(t, key)...)...)
+	require.NoError(t, err, "import private key")
+
+	public := []pkcs11.Attribute{
+		attr(pkcs11.AttrClass, pkcs11.ULong(pkcs11.ClassPublicKey)),
+		attr(pkcs11.AttrToken, ckTrue),
+		attr(attrPrivate, ckFalse),
+		attr(attrVerify, ckTrue),
+		attr(pkcs11.AttrLabel, []byte(label)),
+		attr(pkcs11.AttrID, id),
+	}
+	_, err = session.CreateObject(append(public, publicKeyAttributes(t, key)...)...)
+	require.NoError(t, err, "import public key")
+	return id
+}
+
+func importCertificate(t *testing.T, uri string, leaf *x509.Certificate, id []byte) {
+	t.Helper()
+	session := readWriteSession(t, uri)
+	defer session.Close()
+
+	serial, err := asn1.Marshal(leaf.SerialNumber)
+	require.NoError(t, err)
+	_, err = session.CreateObject(
+		attr(pkcs11.AttrClass, pkcs11.ULong(pkcs11.ClassCertificate)),
+		attr(pkcs11.AttrCertificateType, pkcs11.ULong(pkcs11.CertificateX509)),
+		attr(pkcs11.AttrToken, ckTrue),
+		attr(attrPrivate, ckFalse),
+		attr(pkcs11.AttrLabel, []byte(leaf.Subject.CommonName)),
+		attr(pkcs11.AttrID, id),
+		attr(pkcs11.AttrSubject, leaf.RawSubject),
+		attr(attrIssuer, leaf.RawIssuer),
+		attr(attrSerialNumber, serial),
+		attr(pkcs11.AttrValue, leaf.Raw),
+	)
+	require.NoError(t, err, "import certificate")
+}
+
+func readWriteSession(t *testing.T, uri string) *pkcs11.Session {
+	t.Helper()
+	parsed, err := pkcs11.ParseURI(uri)
+	require.NoError(t, err)
+	module, err := pkcs11.Load(parsed.Module())
+	require.NoError(t, err)
+	pin, err := parsed.PIN()
+	require.NoError(t, err)
+	session, err := module.OpenReadWriteSession(parsed.Token, pin)
+	require.NoError(t, err)
+	return session
+}
+
+func privateKeyAttributes(t *testing.T, key crypto.Signer) []pkcs11.Attribute {
+	t.Helper()
+	switch k := key.(type) {
+	case *ecdsa.PrivateKey:
+		return []pkcs11.Attribute{
+			attr(pkcs11.AttrKeyType, pkcs11.ULong(pkcs11.KeyEC)),
+			attr(pkcs11.AttrECParams, oidP256),
+			attr(pkcs11.AttrValue, ecPrivateScalar(t, k)),
+		}
+	case *rsa.PrivateKey:
+		k.Precompute()
+		return []pkcs11.Attribute{
+			attr(pkcs11.AttrKeyType, pkcs11.ULong(pkcs11.KeyRSA)),
+			attr(pkcs11.AttrModulus, k.N.Bytes()),
+			attr(pkcs11.AttrPublicExponent, big.NewInt(int64(k.E)).Bytes()),
+			attr(attrPrivateExponent, k.D.Bytes()),
+			attr(attrPrime1, k.Primes[0].Bytes()),
+			attr(attrPrime2, k.Primes[1].Bytes()),
+			attr(attrExponent1, k.Precomputed.Dp.Bytes()),
+			attr(attrExponent2, k.Precomputed.Dq.Bytes()),
+			attr(attrCoefficient, k.Precomputed.Qinv.Bytes()),
+		}
+	}
+	t.Fatalf("unsupported key %T", key)
+	return nil
+}
+
+// publicKeyAttributes describes the CKO_PUBLIC_KEY object tokens keep next to a private
+// key, which is what the store reads to pair a certificate file with its key.
+func publicKeyAttributes(t *testing.T, key crypto.Signer) []pkcs11.Attribute {
+	t.Helper()
+	switch k := key.(type) {
+	case *ecdsa.PrivateKey:
+		point := append([]byte{4}, k.X.FillBytes(make([]byte, 32))...)
+		point = append(point, k.Y.FillBytes(make([]byte, 32))...)
+		wrapped, err := asn1.Marshal(point)
+		require.NoError(t, err)
+		return []pkcs11.Attribute{
+			attr(pkcs11.AttrKeyType, pkcs11.ULong(pkcs11.KeyEC)),
+			attr(pkcs11.AttrECParams, oidP256),
+			attr(pkcs11.AttrECPoint, wrapped),
+		}
+	case *rsa.PrivateKey:
+		return []pkcs11.Attribute{
+			attr(pkcs11.AttrKeyType, pkcs11.ULong(pkcs11.KeyRSA)),
+			attr(pkcs11.AttrModulus, k.N.Bytes()),
+			attr(pkcs11.AttrPublicExponent, big.NewInt(int64(k.E)).Bytes()),
+		}
+	}
+	t.Fatalf("unsupported key %T", key)
+	return nil
+}
+
+func attr(typ uint, value []byte) pkcs11.Attribute {
+	return pkcs11.Attribute{Type: typ, Value: value}
+}
+
+// pkcs11TestStore builds the store for the token NB_TEST_PKCS11_URI names, skipping when
+// no token is configured or this build lacks PKCS#11 support.
+func pkcs11TestStore(t *testing.T, certDir string) (*pkcs11Store, string) {
+	t.Helper()
+	uri := os.Getenv(testPKCS11URIEnv)
+	if uri == "" {
+		t.Skipf("set %s to a PKCS#11 URI with a PIN to run", testPKCS11URIEnv)
+	}
+	store, err := newPKCS11Store(PKCS11Config{URI: uri}, certDir)
+	require.NoError(t, err)
+	if _, err := pkcs11.Load(store.uri.Module()); errors.Is(err, pkcs11.ErrUnsupported) {
+		t.Skip(err)
+	}
+	return store, uri
+}
+
+// TestCollect_PKCS11KeyWithFileCertificate covers the split layout: the key lives on the
+// token, the certificate is a PEM file in the directory, and the two are paired by public
+// key because nothing on the token carries the certificate's CKA_ID.
+func TestCollect_PKCS11KeyWithFileCertificate(t *testing.T) {
+	dir := storeDir(t)
+	store, uri := pkcs11TestStore(t, dir)
+
+	keys := map[string]crypto.Signer{"ecdsa": certtest.ECDSAKey(t), "rsa": certtest.RSAKey(t)}
+	for name, key := range keys {
+		t.Run(name, func(t *testing.T) {
+			ca := certtest.NewCA(t, "corp-file-"+name)
+			leaf := ca.Issue(t, key, "device-file-"+name)
+			importKey(t, uri, key, "device-file-"+name)
+			writeFile(t, dir, "device-"+name+".pem", certtest.CertPEM(leaf))
+
+			challenger := certposture.NewChallenger([]byte("secret"))
+			now := time.Now()
+			nonce := challenger.Nonce(peerKey, now)
+			checks := []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{Nonce: nonce, CaCertificates: []string{ca.PEM}}}}
+
+			proofs := Collect(context.Background(), store, checks, peerKey)
+			require.Len(t, proofs, 1, "the token key must prove the certificate kept on disk")
+			chain, err := challenger.Verify(proofs[0], peerKey, now)
+			require.NoError(t, err)
+			assert.True(t, leaf.Equal(chain[0]), "proof must carry the certificate from the directory")
+		})
+	}
+}
+
+func TestPKCS11Store_FileChains(t *testing.T) {
+	ca := certtest.NewCA(t, "corp")
+	dir := storeDir(t)
+	// Only certificate files without a key of their own belong to the token; the file
+	// store answers for the others, and non-certificate files are ignored.
+	writeFile(t, dir, "device.pem", certtest.CertPEM(ca.Issue(t, certtest.ECDSAKey(t), "device")))
+	writeFile(t, dir, "ca.crt", ca.PEM)
+	keyed := certtest.ECDSAKey(t)
+	writeFile(t, dir, "inline.pem", certtest.CertPEM(ca.Issue(t, keyed, "inline"))+certtest.KeyPEM(t, keyed))
+	writeFile(t, dir, "sibling.crt", certtest.CertPEM(ca.Issue(t, keyed, "sibling")))
+	writeFile(t, dir, "sibling.key", certtest.KeyPEM(t, keyed))
+	writeFile(t, dir, "notes.txt", "not a certificate")
+
+	// An intermediate that only a keyed file carries still has to reach the pool a token
+	// certificate's chain is built from.
+	root := certtest.NewCA(t, "corp-root")
+	intermediateCA := certtest.NewIntermediate(t, root, "corp-intermediate")
+	chained := certtest.ECDSAKey(t)
+	writeFile(t, dir, "chained.pem", certtest.CertPEM(intermediateCA.Issue(t, chained, "chained"))+certtest.CertPEM(intermediateCA.Cert)+certtest.KeyPEM(t, chained))
+
+	chains, extra, err := (&pkcs11Store{uri: &pkcs11.URI{}, certDir: dir}).fileChains()
+	require.NoError(t, err)
+	require.NotEmpty(t, extra, "the keyed file's certificates are offered for chain building")
+	tokenLeaf := intermediateCA.Issue(t, certtest.ECDSAKey(t), "token-leaf")
+	chain := buildChain(tokenLeaf, extra)
+	require.Len(t, chain, 2, "a token certificate is completed through the intermediate only the keyed file holds")
+	assert.True(t, intermediateCA.Cert.Equal(chain[1]), "the second certificate is that intermediate")
+	var subjects []string
+	for _, chain := range chains {
+		subjects = append(subjects, chain[0].Subject.CommonName)
+	}
+	assert.ElementsMatch(t, []string{"device", "corp"}, subjects, "only key-less certificate files are left to the token")
+
+	chains, extra, err = (&pkcs11Store{uri: &pkcs11.URI{}}).fileChains()
+	require.NoError(t, err)
+	assert.Empty(t, chains, "no directory configured means no file certificates")
+	assert.Empty(t, extra, "and no extra intermediates")
+}
+
+func TestNewPKCS11Store_PIN(t *testing.T) {
+	tests := []struct {
+		name       string
+		cfg        PKCS11Config
+		wantPIN    []byte
+		wantModule string
+	}{
+		{"pin with a token label opens that token through p11-kit", PKCS11Config{URI: "pkcs11:token=netbird", PIN: "1234"}, []byte("1234"), pkcs11.DefaultModule},
+		{"pin field wins over pin-value", PKCS11Config{URI: "pkcs11:token=netbird?module-path=" + absModule("x.so") + "&pin-value=0000", PIN: "1234"}, []byte("1234"), absModule("x.so")},
+		{"uri pin-value stands in for a missing field", PKCS11Config{URI: "pkcs11:token=netbird?pin-value=0000"}, []byte("0000"), pkcs11.DefaultModule},
+		{"no pin at all means no login", PKCS11Config{URI: "pkcs11:token=netbird"}, nil, pkcs11.DefaultModule},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			store, err := newPKCS11Store(tt.cfg, "")
+			require.NoError(t, err)
+			pin, err := store.userPIN()
+			require.NoError(t, err)
+			assert.Equal(t, tt.wantPIN, pin, "PIN, nil meaning no login")
+			assert.Equal(t, tt.wantModule, store.uri.Module(), "module to load")
+		})
+	}
+
+	_, err := newPKCS11Store(PKCS11Config{URI: "not-a-pkcs11-uri", PIN: "1234"}, "")
+	assert.Error(t, err, "a malformed URI must not be silently replaced by the defaults")
+
+	for name, cfg := range map[string]PKCS11Config{
+		"env pin without uri":      {PIN: "1234"},
+		"env pin, uri lacks token": {URI: "pkcs11:?module-path=" + absModule("x.so"), PIN: "1234"},
+		"inline pin-value only":    {URI: "pkcs11:?pin-value=0000"},
+		"pin-source only":          {URI: "pkcs11:?pin-source=file:/etc/netbird/pkcs11.pin"},
+	} {
+		_, err := newPKCS11Store(cfg, "")
+		assert.ErrorIs(t, err, errPINNeedsToken, "%s: a PIN must not go to whichever token is listed first", name)
+	}
+}
+
+// TestPKCS11Store_WrongPINIsTriedOnce logs in to the real token with a wrong PIN: the
+// token refuses it, and the next collection refuses to send the same PIN again rather
+// than spending another attempt of the token's lockout counter. The one attempt it does
+// spend counts against a real token's lockout, so it runs only on a token marked
+// disposable through NB_TEST_PKCS11_DISPOSABLE.
+func TestPKCS11Store_WrongPINIsTriedOnce(t *testing.T) {
+	disposable, _ := strconv.ParseBool(os.Getenv(testPKCS11DisposableEnv))
+	if !disposable {
+		t.Skipf("set %s=1 to spend a wrong-PIN attempt on the token", testPKCS11DisposableEnv)
+	}
+	_, uri := pkcs11TestStore(t, "")
+
+	wrongPIN := "wrong-pin-" + t.Name()
+	store, err := newPKCS11Store(PKCS11Config{URI: uri, PIN: wrongPIN}, "")
+	require.NoError(t, err)
+
+	_, err = store.Candidates(context.Background())
+	require.Error(t, err)
+	assert.True(t, pkcs11.PINRejected(err), "the token itself rejects the PIN: %v", err)
+
+	_, err = store.Candidates(context.Background())
+	assert.ErrorIs(t, err, errPINRejectedBefore, "the rejected PIN is not sent to the token again")
+
+	good, err := newPKCS11Store(PKCS11Config{URI: uri}, "")
+	require.NoError(t, err)
+	_, err = good.Candidates(context.Background())
+	assert.NoError(t, err, "the correct PIN for the same token is unaffected")
+}
+
+// absModule is an absolute module path on the platform the test runs on, as module-path
+// must be absolute.
+func absModule(name string) string {
+	if runtime.GOOS == "windows" {
+		return `C:\lib\` + name
+	}
+	return "/lib/" + name
+}
+
+// ecPrivateScalar returns the raw private scalar the token stores in CKA_VALUE.
+func ecPrivateScalar(t *testing.T, k *ecdsa.PrivateKey) []byte {
+	t.Helper()
+	raw, err := k.Bytes()
+	require.NoError(t, err)
+	return raw
+}

client/internal/certproof/signattempts.go

@@ -0,0 +1,24 @@
+package certproof
+
+import "errors"
+
+// signAttempts tracks the identities tried to sign with, for a certificate that can match
+// more than one of them.
+type signAttempts struct {
+	errs []error
+}
+
+// try runs sign and reports its signature and whether it succeeded. A failure is kept.
+func (a *signAttempts) try(sign func() ([]byte, error)) ([]byte, bool) {
+	signature, err := sign()
+	if err != nil {
+		a.errs = append(a.errs, err)
+		return nil, false
+	}
+	return signature, true
+}
+
+// err joins the failures of the attempts, nil when there were none.
+func (a *signAttempts) err() error {
+	return errors.Join(a.errs...)
+}

client/internal/certproof/signattempts_test.go

@@ -0,0 +1,41 @@
+package certproof
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var errNeedsApprovalForTest = errors.New("key needs approval")
+
+// TestSignAttempts_FallsThroughToTheNextIdentity: a certificate can sit in a keychain with
+// more than one key, of which only some can sign. A failure moves on, and an identity that
+// signs ends the search without reporting the earlier failure.
+func TestSignAttempts_FallsThroughToTheNextIdentity(t *testing.T) {
+	var attempts signAttempts
+
+	signature, ok := attempts.try(func() ([]byte, error) { return nil, errNeedsApprovalForTest })
+	assert.False(t, ok, "a failing identity does not end the search")
+	assert.Nil(t, signature)
+
+	signature, ok = attempts.try(func() ([]byte, error) { return []byte("sig"), nil })
+	require.True(t, ok, "the next identity signs")
+	assert.Equal(t, []byte("sig"), signature)
+}
+
+// TestSignAttempts_KeepsEveryFailure: when no identity signs, the approval a user has to
+// give must not be hidden behind the failure of a later identity.
+func TestSignAttempts_KeepsEveryFailure(t *testing.T) {
+	var attempts signAttempts
+	assert.NoError(t, attempts.err(), "no attempts, no error")
+
+	attempts.try(func() ([]byte, error) { return nil, errNeedsApprovalForTest })
+	attempts.try(func() ([]byte, error) { return nil, errors.New("key is gone") })
+
+	err := attempts.err()
+	require.Error(t, err)
+	assert.ErrorIs(t, err, errNeedsApprovalForTest, "the earlier approval error survives the later failure")
+	assert.ErrorContains(t, err, "key is gone")
+}

client/internal/certproof/store.go

@@ -0,0 +1,266 @@
+package certproof
+
+import (
+	"context"
+	"crypto"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	StoreDirEnv     = "NB_CERT_STORE_DIR"
+	defaultStoreDir = "/etc/netbird/certs"
+
+	// maxStoreFileSize bounds a certificate or key file of the PEM directory. A chain with
+	// its key is a few kilobytes.
+	maxStoreFileSize = 1 << 20
+)
+
+// errKeyMismatch rejects a key that does not belong to the certificate it sits with: it
+// would sign a proof management can only reject, in place of a usable later candidate.
+var (
+	errKeyMismatch  = errors.New("private key does not match the certificate")
+	errNoSiblingKey = errors.New("no key file next to the certificate")
+)
+
+// Candidate is a certificate chain the peer can sign for. Signer never exposes the key.
+// Chain is leaf first. Intermediates holds every other certificate the store has, so a
+// path to a challenge's CAs can be found even where Chain followed a different issuer,
+// such as an expired copy of a renewed intermediate.
+type Candidate struct {
+	Chain         []*x509.Certificate
+	Signer        crypto.Signer
+	Intermediates []*x509.Certificate
+}
+
+// issuers is every certificate other than the leaf that a path may run through.
+func (c Candidate) issuers() []*x509.Certificate {
+	return append(slices.Clip(c.Chain[1:]), c.Intermediates...)
+}
+
+// Store yields the certificates a peer may prove possession of. fileStore is the PEM
+// directory implementation; OS keystores (CNG, Keychain, PKCS#11) slot in here.
+type Store interface {
+	Candidates(ctx context.Context) ([]Candidate, error)
+}
+
+// Config selects where the daemon looks for certificates. PKCS11 names a token whose keys
+// sign for certificates on the token or in the PEM directory, which NB_CERT_STORE_DIR
+// names on Linux, /etc/netbird/certs by default.
+//
+// ProfileOwner is the OS account the active profile belongs to. On macOS and Windows only
+// that account's certificate store is consulted for user certificates, so on a machine
+// with several people signed in the result does not depend on who else is logged in.
+// Empty means the profile has no owner, and only the user at the physical console counts.
+// OwnerUnknown means the owner could not be determined, and no user store is consulted:
+// guessing would let whoever sits at the console answer for the profile.
+type Config struct {
+	PKCS11       PKCS11Config
+	ProfileOwner string
+	OwnerUnknown bool
+}
+
+// fileStore reads PEM files from a directory. A file holds the chain (leaf first) and
+// either its private key or a sibling "<name>.key" file holds it. The key is a plain
+// PKCS#8, EC or RSA key, or a TSS2 key the TPM signs with.
+type fileStore struct {
+	dir string
+}
+
+func newFileStore(dir string) *fileStore {
+	return &fileStore{dir: dir}
+}
+
+func StoreDir() string {
+	if dir := os.Getenv(StoreDirEnv); dir != "" {
+		return dir
+	}
+	return defaultStoreDir
+}
+
+func (s *fileStore) Candidates(_ context.Context) ([]Candidate, error) {
+	paths, err := certFiles(s.dir)
+	if err != nil {
+		return nil, err
+	}
+
+	var candidates []Candidate
+	for _, path := range paths {
+		chain, signer, err := loadPEM(path)
+		if err != nil {
+			log.Warnf("skipping certificate %s: %v", path, err)
+			continue
+		}
+		if signer == nil {
+			log.Debugf("certificate %s has no key file, only a token can sign for it", path)
+			continue
+		}
+		candidates = append(candidates, Candidate{Chain: chain, Signer: signer})
+	}
+	return candidates, nil
+}
+
+// certFiles lists the certificate files in dir, none when the directory does not exist.
+// The directory is checked before it is listed, so one that others can write to is
+// refused before its entries are read.
+func certFiles(dir string) ([]string, error) {
+	err := checkStoreDir(dir)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("refusing certificate store: %w", err)
+	}
+	entries, err := os.ReadDir(dir)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("read certificate store %s: %w", dir, err)
+	}
+	var paths []string
+	for _, entry := range entries {
+		if !entry.IsDir() && isCertFile(entry.Name()) {
+			paths = append(paths, filepath.Join(dir, entry.Name()))
+		}
+	}
+	return paths, nil
+}
+
+// loadPEM reads a certificate file and its private key, held in the file itself or in
+// the sibling "<name>.key" file. The signer is nil when neither holds a key.
+func loadPEM(path string) ([]*x509.Certificate, crypto.Signer, error) {
+	data, err := readStoreFile(path)
+	if err != nil {
+		return nil, nil, err
+	}
+	chain, signer, err := parsePEM(data)
+	if err != nil {
+		return nil, nil, err
+	}
+	if len(chain) == 0 {
+		return nil, nil, errors.New("no certificate")
+	}
+	if signer == nil {
+		signer, err = siblingKey(path)
+		switch {
+		case errors.Is(err, errNoSiblingKey):
+			// A certificate with no key of its own: the token store pairs it later.
+			return chain, nil, nil
+		case err != nil:
+			return nil, nil, err
+		}
+	}
+	if !samePublicKey(signer.Public(), chain[0].PublicKey) {
+		return nil, nil, errKeyMismatch
+	}
+	return chain, signer, nil
+}
+
+// siblingKey reads the private key from the "<name>.key" file next to a certificate
+// file, reporting errNoSiblingKey when there is none.
+func siblingKey(path string) (crypto.Signer, error) {
+	keyData, err := readStoreFile(strings.TrimSuffix(path, filepath.Ext(path)) + ".key")
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, errNoSiblingKey
+	}
+	if err != nil {
+		return nil, fmt.Errorf("read key file: %w", err)
+	}
+	_, signer, err := parsePEM(keyData)
+	if err != nil {
+		return nil, err
+	}
+	if signer == nil {
+		return nil, errors.New("no private key in key file")
+	}
+	return signer, nil
+}
+
+func samePublicKey(a, b crypto.PublicKey) bool {
+	equaler, ok := a.(interface{ Equal(crypto.PublicKey) bool })
+	return ok && equaler.Equal(b)
+}
+
+func parsePEM(data []byte) ([]*x509.Certificate, crypto.Signer, error) {
+	var chain []*x509.Certificate
+	var signer crypto.Signer
+	for {
+		var block *pem.Block
+		block, data = pem.Decode(data)
+		if block == nil {
+			return chain, signer, nil
+		}
+		switch block.Type {
+		case "CERTIFICATE":
+			cert, err := x509.ParseCertificate(block.Bytes)
+			if err != nil {
+				return nil, nil, fmt.Errorf("parse certificate: %w", err)
+			}
+			chain = append(chain, cert)
+		case "PRIVATE KEY", "EC PRIVATE KEY", "RSA PRIVATE KEY", tss2KeyPEMType:
+			key, err := parsePrivateKey(block)
+			if err != nil {
+				return nil, nil, err
+			}
+			signer = key
+		}
+	}
+}
+
+func parsePrivateKey(block *pem.Block) (crypto.Signer, error) {
+	var key any
+	var err error
+	switch block.Type {
+	case tss2KeyPEMType:
+		return parseTSS2Key(block.Bytes)
+	case "EC PRIVATE KEY":
+		key, err = x509.ParseECPrivateKey(block.Bytes)
+	case "RSA PRIVATE KEY":
+		key, err = x509.ParsePKCS1PrivateKey(block.Bytes)
+	default:
+		key, err = x509.ParsePKCS8PrivateKey(block.Bytes)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("parse private key: %w", err)
+	}
+	signer, ok := key.(crypto.Signer)
+	if !ok {
+		return nil, errors.New("private key cannot sign")
+	}
+	return signer, nil
+}
+
+func isCertFile(name string) bool {
+	switch strings.ToLower(filepath.Ext(name)) {
+	case ".pem", ".crt", ".cer":
+		return true
+	}
+	return false
+}
+
+// Stores queries several stores and carries on when one fails, so a broken token cannot
+// hide the certificates a directory holds. A failure is logged instead of returned
+// because Collect treats a store error as "no proofs at all".
+type Stores []Store
+
+func (s Stores) Candidates(ctx context.Context) ([]Candidate, error) {
+	var all []Candidate
+	for _, store := range s {
+		candidates, err := store.Candidates(ctx)
+		if err != nil {
+			log.Warnf("certificate store %T unavailable: %v", store, err)
+			continue
+		}
+		all = append(all, candidates...)
+	}
+	return all, nil
+}

client/internal/certproof/store_other.go

@@ -0,0 +1,39 @@
+//go:build ((!darwin && !windows) || ios) && !js
+
+package certproof
+
+import (
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/pkcs11"
+)
+
+var unsupportedTokenOnce sync.Once
+
+// DefaultStore is the PEM directory named by NB_CERT_STORE_DIR, or /etc/netbird/certs.
+func DefaultStore() Store {
+	return newFileStore(StoreDir())
+}
+
+// storeWithToken reads the PEM directory cfg names, joined by the PKCS#11 token when cfg
+// names one. The token pairs the directory's key-less certificates with its own keys.
+func storeWithToken(cfg Config) Store {
+	files := newFileStore(StoreDir())
+	if cfg.PKCS11.URI == "" && cfg.PKCS11.PIN == "" {
+		return files
+	}
+	if !pkcs11.Supported() {
+		unsupportedTokenOnce.Do(func() {
+			log.Warnf("ignoring the configured PKCS#11 token: %v", pkcs11.ErrUnsupported)
+		})
+		return files
+	}
+	token, err := newPKCS11Store(cfg.PKCS11, StoreDir())
+	if err != nil {
+		log.Warnf("ignoring PKCS#11 URI: %v", err)
+		return files
+	}
+	return Stores{files, token}
+}

client/internal/certproof/store_other_test.go

@@ -0,0 +1,44 @@
+//go:build ((!darwin && !windows) || ios) && !js
+
+package certproof
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/pkcs11"
+)
+
+func TestStoreWithToken(t *testing.T) {
+	dir := storeDir(t)
+	t.Setenv(StoreDirEnv, dir)
+
+	files, ok := storeWithToken(Config{}).(*fileStore)
+	require.True(t, ok, "no token configured reads the PEM directory alone")
+	assert.Equal(t, dir, files.dir, "the directory comes from NB_CERT_STORE_DIR")
+
+	assert.IsType(t, &fileStore{}, storeWithToken(Config{PKCS11: PKCS11Config{URI: "not-a-pkcs11-uri"}}), "an invalid URI must not hide the PEM directory")
+	assert.IsType(t, &fileStore{}, storeWithToken(Config{PKCS11: PKCS11Config{PIN: "1234"}}), "a PIN naming no token is refused and leaves the PEM directory")
+
+	configured := map[string]PKCS11Config{
+		"env pin with token uri": {URI: "pkcs11:token=netbird", PIN: "1234"},
+		"uri alone":              {URI: "pkcs11:token=netbird?pin-value=1234"},
+	}
+	if !pkcs11.Supported() {
+		for name, cfg := range configured {
+			assert.IsType(t, &fileStore{}, storeWithToken(Config{PKCS11: cfg}),
+				"%s: a build without PKCS#11 support reads the PEM directory alone", name)
+		}
+		return
+	}
+	for name, cfg := range configured {
+		store, ok := storeWithToken(Config{PKCS11: cfg}).(Stores)
+		require.True(t, ok, "%s joins the token to the PEM directory", name)
+		require.Len(t, store, 2, name)
+		token, ok := store[1].(*pkcs11Store)
+		require.True(t, ok, name)
+		assert.Equal(t, dir, token.certDir, "%s: the token pairs certificates from the same directory", name)
+	}
+}

client/internal/certproof/store_tpm_test.go

@@ -0,0 +1,96 @@
+package certproof
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"encoding/pem"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/google/go-tpm/legacy/tpm2"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/tpm"
+	"github.com/netbirdio/netbird/client/internal/tpm/tpmtest"
+	"github.com/netbirdio/netbird/shared/management/certposture"
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+	"github.com/netbirdio/netbird/shared/management/proto"
+)
+
+func TestFileStore_TPMKeyFile(t *testing.T) {
+	ca := certtest.NewCA(t, "corp")
+	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	require.NoError(t, err)
+	leaf := ca.Issue(t, key, "device")
+
+	dir := storeDir(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(leaf))
+	writeFile(t, dir, "device.key", tpmtest.KeyPEM(t, &key.PublicKey))
+
+	// A key that needs a password can never be used silently, so its certificate is skipped.
+	locked := certtest.ECDSAKey(t)
+	writeFile(t, dir, "locked.pem", certtest.CertPEM(ca.Issue(t, locked, "locked")))
+	writeFile(t, dir, "locked.key", tpmtest.KeyPEM(t, locked.Public().(*ecdsa.PublicKey), tpmtest.WithAuth()))
+
+	candidates, err := newFileStore(dir).Candidates(context.Background())
+	require.NoError(t, err)
+	require.Len(t, candidates, 1, "only the key without an authorization value is usable")
+	assert.True(t, leaf.Equal(candidates[0].Chain[0]), "candidate must carry the device certificate")
+	assert.True(t, key.PublicKey.Equal(candidates[0].Signer.Public()), "signer must report the certificate's key")
+}
+
+// TestCollect_TPMKeyEndToEnd runs against the TPM named by NB_TPM_DEVICE, for example a
+// swtpm started with:
+//
+//	swtpm socket --tpm2 --server type=unixio,path=/tmp/swtpm.sock \
+//	  --ctrl type=unixio,path=/tmp/swtpm.ctrl --flags not-need-init,startup-clear
+//
+// It creates a key the way tpm2-openssl does, under a transient ECC primary in the owner
+// hierarchy, and proves the certificate for it through the regular file store.
+func TestCollect_TPMKeyEndToEnd(t *testing.T) {
+	if os.Getenv(tpm.DeviceEnv) == "" {
+		t.Skipf("set %s to a TPM device or swtpm socket to run", tpm.DeviceEnv)
+	}
+	public, private := createTPMKey(t)
+	keyPEM := tpmtest.EncodePEM(t, public, private)
+	block, _ := pem.Decode([]byte(keyPEM))
+	require.NotNil(t, block)
+	signer, err := tpm.ParseKey(block.Bytes)
+	require.NoError(t, err)
+
+	ca := certtest.NewCA(t, "corp")
+	leaf := ca.Issue(t, signer, "device")
+	dir := storeDir(t)
+	writeFile(t, dir, "device.pem", certtest.CertPEM(leaf))
+	writeFile(t, dir, "device.key", keyPEM)
+
+	challenger := certposture.NewChallenger([]byte("secret"))
+	now := time.Now()
+	nonce := challenger.Nonce(peerKey, now)
+	checks := []*proto.Checks{{CertificateChallenge: &proto.CertificateChallenge{Nonce: nonce, CaCertificates: []string{ca.PEM}}}}
+
+	proofs := Collect(context.Background(), newFileStore(dir), checks, peerKey)
+	require.Len(t, proofs, 1, "the TPM-held key must prove the certificate")
+	chain, err := challenger.Verify(proofs[0], peerKey, now)
+	require.NoError(t, err)
+	assert.True(t, leaf.Equal(chain[0]), "proof must carry the device certificate")
+}
+
+func createTPMKey(t *testing.T) (public, private []byte) {
+	t.Helper()
+	rwc, err := tpm.Open()
+	require.NoError(t, err)
+	defer func() { _ = rwc.Close() }()
+
+	parent, _, err := tpm2.CreatePrimary(rwc, tpm2.HandleOwner, tpm2.PCRSelection{}, "", "", tpmtest.ECCSRKTemplate)
+	require.NoError(t, err)
+	defer func() { _ = tpm2.FlushContext(rwc, parent) }()
+
+	private, public, _, _, _, err = tpm2.CreateKey(rwc, parent, tpm2.PCRSelection{}, "", "", tpmtest.SigningTemplate())
+	require.NoError(t, err)
+	return public, private
+}

client/internal/certproof/store_tss2.go

@@ -0,0 +1,17 @@
+//go:build !js
+
+package certproof
+
+import (
+	"crypto"
+
+	"github.com/netbirdio/netbird/client/internal/tpm"
+)
+
+// tss2KeyPEMType is the PEM block type of a TPM 2.0 key file.
+const tss2KeyPEMType = tpm.KeyPEMType
+
+// parseTSS2Key returns a signer for a TPM-held key file that signs inside the TPM.
+func parseTSS2Key(der []byte) (crypto.Signer, error) {
+	return tpm.ParseKey(der)
+}

client/internal/certproof/store_tss2_js.go

@@ -0,0 +1,16 @@
+//go:build js
+
+package certproof
+
+import (
+	"crypto"
+	"errors"
+)
+
+// tss2KeyPEMType is the PEM block type of a TPM 2.0 key file. A browser has no TPM, so
+// the TPM library stays out of the WebAssembly build and such a key is refused.
+const tss2KeyPEMType = "TSS2 PRIVATE KEY"
+
+func parseTSS2Key([]byte) (crypto.Signer, error) {
+	return nil, errors.New("TPM keys are not supported in this build")
+}

client/internal/certproof/storefile_other.go

@@ -0,0 +1,34 @@
+//go:build !unix
+
+package certproof
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+// readStoreFile reads a certificate or key file of the PEM directory, up to the size
+// limit. Ownership is checked on Unix only; elsewhere the PEM directory is not the store
+// the daemon reads by default.
+func readStoreFile(path string) ([]byte, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = f.Close() }()
+
+	data, err := io.ReadAll(io.LimitReader(f, maxStoreFileSize+1))
+	if err != nil {
+		return nil, fmt.Errorf("read %s: %w", path, err)
+	}
+	if len(data) > maxStoreFileSize {
+		return nil, fmt.Errorf("%s is over the %d byte limit", path, maxStoreFileSize)
+	}
+	return data, nil
+}
+
+// checkStoreDir accepts any directory where the PEM directory is not a default store.
+func checkStoreDir(string) error {
+	return nil
+}

client/internal/certproof/storefile_unix.go

@@ -0,0 +1,101 @@
+//go:build unix
+
+package certproof
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+)
+
+// readStoreFile reads a certificate or key file of the PEM directory as the daemon may
+// trust it: the path must not be a symlink and must be a regular file that only root or
+// this process's own user can write. Otherwise a user able to place or redirect a file
+// could make the daemon sign with a key of their choosing, or with a root-only key kept
+// elsewhere on the machine. The file is checked through the descriptor it is read from,
+// so it cannot be swapped between the check and the read.
+func readStoreFile(path string) ([]byte, error) {
+	// O_NONBLOCK keeps a FIFO planted in the directory from blocking the open; the
+	// regular-file check below then refuses it.
+	f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = f.Close() }()
+
+	info, err := f.Stat()
+	if err != nil {
+		return nil, fmt.Errorf("stat %s: %w", path, err)
+	}
+	if !info.Mode().IsRegular() {
+		return nil, fmt.Errorf("%s is not a regular file", path)
+	}
+	if err := checkTrustedOwner(info); err != nil {
+		return nil, fmt.Errorf("%s: %w", path, err)
+	}
+	if info.Size() > maxStoreFileSize {
+		return nil, fmt.Errorf("%s is %d bytes, over the %d byte limit", path, info.Size(), maxStoreFileSize)
+	}
+	data, err := io.ReadAll(io.LimitReader(f, maxStoreFileSize+1))
+	if err != nil {
+		return nil, fmt.Errorf("read %s: %w", path, err)
+	}
+	if len(data) > maxStoreFileSize {
+		return nil, fmt.Errorf("%s grew past the %d byte limit while being read", path, maxStoreFileSize)
+	}
+	return data, nil
+}
+
+// checkStoreDir refuses a PEM directory that someone other than root or this process's
+// user could add files to or rename files in. The configured path may be a symlink, as
+// distributions place certificate directories behind them, but only one root or this
+// process's user owns: otherwise whoever owns the link could point it at any directory.
+func checkStoreDir(dir string) error {
+	link, err := os.Lstat(dir)
+	if err != nil {
+		return err
+	}
+	if link.Mode()&os.ModeSymlink != 0 {
+		if err := checkTrustedUID(link); err != nil {
+			return fmt.Errorf("symlink %s: %w", dir, err)
+		}
+	}
+	info, err := os.Stat(dir)
+	if err != nil {
+		return err
+	}
+	if !info.IsDir() {
+		return fmt.Errorf("%s is not a directory", dir)
+	}
+	if err := checkTrustedOwner(info); err != nil {
+		return fmt.Errorf("%s: %w", dir, err)
+	}
+	return nil
+}
+
+// checkTrustedOwner requires info to belong to root or to this process's user and to be
+// writable by nobody else. Group write is refused even for root's group, which ordinary
+// users may be members of. An owner that cannot be read is refused.
+func checkTrustedOwner(info os.FileInfo) error {
+	if err := checkTrustedUID(info); err != nil {
+		return err
+	}
+	if perm := info.Mode().Perm(); perm&0o022 != 0 {
+		return fmt.Errorf("writable by group or other users (mode %#o)", perm)
+	}
+	return nil
+}
+
+// checkTrustedUID requires info to belong to root or to this process's user.
+func checkTrustedUID(info os.FileInfo) error {
+	st, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return errors.New("owner cannot be determined")
+	}
+	if st.Uid != 0 && int(st.Uid) != os.Geteuid() {
+		return fmt.Errorf("owned by uid %d, not by root", st.Uid)
+	}
+	return nil
+}

client/internal/certproof/storefile_unix_test.go

@@ -0,0 +1,136 @@
+//go:build unix
+
+package certproof
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"syscall"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/shared/management/certposture/certtest"
+)
+
+// devicePair writes a certificate and its key as separate files into dir.
+func devicePair(t *testing.T, dir string) {
+	t.Helper()
+	ca := certtest.NewCA(t, "corp-root")
+	key := certtest.ECDSAKey(t)
+	writeFile(t, dir, "device.crt", certtest.CertPEM(ca.Issue(t, key, "device")))
+	writeFile(t, dir, "device.key", certtest.KeyPEM(t, key))
+}
+
+func candidates(t *testing.T, dir string) ([]Candidate, error) {
+	t.Helper()
+	return newFileStore(dir).Candidates(context.Background())
+}
+
+func TestFileStore_AcceptsAPrivatePair(t *testing.T) {
+	dir := storeDir(t)
+	devicePair(t, dir)
+
+	got, err := candidates(t, dir)
+	require.NoError(t, err)
+	assert.Len(t, got, 1, "a certificate and key only their owner can write are used")
+}
+
+func TestFileStore_RefusesASymlinkedKey(t *testing.T) {
+	dir := storeDir(t)
+	devicePair(t, dir)
+
+	// The real key moves elsewhere and the directory only links to it, as a user able
+	// to write the directory would do to point the daemon at a key it should not use.
+	elsewhere := filepath.Join(storeDir(t), "other.key")
+	require.NoError(t, os.Rename(filepath.Join(dir, "device.key"), elsewhere))
+	require.NoError(t, os.Symlink(elsewhere, filepath.Join(dir, "device.key")))
+
+	got, err := candidates(t, dir)
+	require.NoError(t, err)
+	assert.Empty(t, got, "a key reached through a symlink is never used")
+}
+
+func TestFileStore_RefusesASymlinkedCertificateFile(t *testing.T) {
+	dir := storeDir(t)
+	other := storeDir(t)
+	devicePair(t, other)
+	require.NoError(t, os.Symlink(filepath.Join(other, "device.crt"), filepath.Join(dir, "device.crt")))
+	require.NoError(t, os.Symlink(filepath.Join(other, "device.key"), filepath.Join(dir, "device.key")))
+
+	got, err := candidates(t, dir)
+	require.NoError(t, err)
+	assert.Empty(t, got, "a certificate file that is a symlink is skipped")
+}
+
+func TestFileStore_RefusesFilesOthersCanWrite(t *testing.T) {
+	for name, mode := range map[string]os.FileMode{"world-writable": 0o602, "group-writable": 0o620} {
+		t.Run(name, func(t *testing.T) {
+			dir := storeDir(t)
+			devicePair(t, dir)
+			require.NoError(t, os.Chmod(filepath.Join(dir, "device.key"), mode))
+
+			got, err := candidates(t, dir)
+			require.NoError(t, err)
+			assert.Empty(t, got, "a key %s may have been replaced by someone else, even when the group is root's", name)
+		})
+	}
+}
+
+func TestFileStore_RefusesADirectoryOthersCanWrite(t *testing.T) {
+	dir := storeDir(t)
+	devicePair(t, dir)
+	require.NoError(t, os.Chmod(dir, 0o777))
+
+	_, err := candidates(t, dir)
+	assert.ErrorContains(t, err, "refusing certificate store", "files in a directory anyone can write are not trusted")
+}
+
+func TestFileStore_SkipsAFIFOWithoutBlocking(t *testing.T) {
+	dir := storeDir(t)
+	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "trap.pem"), 0o600))
+	devicePair(t, dir)
+
+	got, err := candidates(t, dir)
+	require.NoError(t, err)
+	assert.Len(t, got, 1, "a FIFO is skipped and the real pair still loads")
+}
+
+func TestReadStoreFile_RefusesOversizedFiles(t *testing.T) {
+	dir := storeDir(t)
+	path := filepath.Join(dir, "huge.pem")
+	require.NoError(t, os.WriteFile(path, make([]byte, maxStoreFileSize+1), 0o600))
+
+	_, err := readStoreFile(path)
+	assert.ErrorContains(t, err, "limit")
+}
+
+func TestFileStore_AcceptsASymlinkedDirectoryItsOwnerControls(t *testing.T) {
+	target := storeDir(t)
+	devicePair(t, target)
+	link := filepath.Join(storeDir(t), "certs")
+	require.NoError(t, os.Symlink(target, link))
+
+	// The link belongs to this process's user, as one root creates belongs to root.
+	got, err := candidates(t, link)
+	require.NoError(t, err)
+	assert.Len(t, got, 1, "a certificate directory behind a symlink the owner controls is read")
+}
+
+func TestFileStore_ChecksTheDirectoryBeforeListingIt(t *testing.T) {
+	dir := storeDir(t)
+	devicePair(t, dir)
+	require.NoError(t, os.Chmod(dir, 0o777))
+
+	paths, err := certFiles(dir)
+	assert.ErrorContains(t, err, "refusing certificate store")
+	assert.Nil(t, paths, "nothing in a directory anyone can write to is listed")
+}
+
+func TestFileStore_MissingDirectoryIsEmpty(t *testing.T) {
+	paths, err := certFiles(filepath.Join(storeDir(t), "missing"))
+	assert.NoError(t, err, "a store directory that does not exist yet is not an error")
+	assert.Empty(t, paths)
+}

client/internal/certproof/systemstore_windows.go

@@ -0,0 +1,270 @@
+package certproof
+
+import (
+	"bytes"
+	"context"
+	"crypto"
+	"crypto/sha256"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"io"
+	"slices"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+const (
+	personalStore     = "MY"
+	intermediateStore = "CA"
+
+	cryptAcquireSilentFlag          = 0x00000040
+	cryptAcquirePreferNCryptKeyFlag = 0x00020000
+	certNCryptKeySpec               = 0xFFFFFFFF
+	atKeyExchange                   = 1
+	atSignature                     = 2
+	bcryptPadPSS                    = 0x00000008
+)
+
+// errLegacyKey reports a private key CNG cannot open: it lives in a legacy CryptoAPI
+// provider, which only offers PKCS#1 v1.5 and no RSA-PSS or ECDSA.
+var errLegacyKey = errors.New("private key is held by a legacy CryptoAPI provider, which certificate posture cannot sign with")
+
+var (
+	crypt32 = windows.NewLazySystemDLL("crypt32.dll")
+	ncrypt  = windows.NewLazySystemDLL("ncrypt.dll")
+
+	procCryptAcquireCertificatePrivateKey = crypt32.NewProc("CryptAcquireCertificatePrivateKey")
+	procNCryptSignHash                    = ncrypt.NewProc("NCryptSignHash")
+	procNCryptFreeObject                  = ncrypt.NewProc("NCryptFreeObject")
+)
+
+type bcryptPSSPaddingInfo struct {
+	algID *uint16
+	salt  uint32
+}
+
+// DefaultStore is the local machine's personal certificate store, where device
+// certificates enrolled through AD or Intune are kept.
+func DefaultStore() Store {
+	return newSystemStore()
+}
+
+// systemStore yields the identities of a personal certificate store, completing their
+// chains from the matching intermediate CA store. Keys are used through CNG and never
+// exported.
+//
+// The location decides whose certificates these are. The local machine store is the one
+// a service reads; the current user store lives in the signed-in user's registry hive
+// with keys protected against their profile, so it is only readable while running as
+// that user.
+type systemStore struct {
+	location uint32
+}
+
+// newSystemStore reads the local machine store, which is what the daemon uses.
+func newSystemStore() *systemStore {
+	return &systemStore{location: windows.CERT_SYSTEM_STORE_LOCAL_MACHINE}
+}
+
+// newUserStore reads the calling user's personal store. It is only useful in a process
+// already running as that user, which is what the posture helper is.
+func newUserStore() *systemStore {
+	return &systemStore{location: windows.CERT_SYSTEM_STORE_CURRENT_USER}
+}
+
+func (s *systemStore) Candidates(_ context.Context) ([]Candidate, error) {
+	leaves, err := storeCertificates(s.location, personalStore)
+	if err != nil {
+		return nil, err
+	}
+	intermediates, err := storeCertificates(s.location, intermediateStore)
+	if err != nil {
+		return nil, err
+	}
+	log.Debugf("certificate store %s holds %d personal certificates and %d intermediates", s, len(leaves), len(intermediates))
+	if len(leaves) == 0 {
+		return nil, nil
+	}
+
+	pool := slices.Concat(intermediates, leaves)
+	candidates := make([]Candidate, 0, len(leaves))
+	for _, leaf := range leaves {
+		chain := buildChain(leaf, pool)
+		log.Debugf("certificate store %s candidate %q issued by %q built a chain of %d certificates", s, leaf.Subject, leaf.Issuer, len(chain))
+		candidates = append(candidates, Candidate{Chain: chain, Signer: &systemStoreSigner{leaf: leaf, location: s.location}, Intermediates: pool})
+	}
+	return candidates, nil
+}
+
+// String names the store location the way the Windows documentation does.
+func (s *systemStore) String() string {
+	if s.location == windows.CERT_SYSTEM_STORE_CURRENT_USER {
+		return "CurrentUser"
+	}
+	return "LocalMachine"
+}
+
+// systemStoreSigner holds only the certificate; the store entry and its key are acquired
+// at signing time so no handles outlive a call.
+type systemStoreSigner struct {
+	leaf     *x509.Certificate
+	location uint32
+}
+
+func (s *systemStoreSigner) Public() crypto.PublicKey {
+	return s.leaf.PublicKey
+}
+
+func (s *systemStoreSigner) Sign(_ io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
+	scheme, err := schemeFor(s.leaf.PublicKey, opts)
+	if err != nil {
+		return nil, err
+	}
+	store, err := openStore(s.location, personalStore)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = windows.CertCloseStore(store, 0) }()
+
+	var signature []byte
+	err = eachCertificate(store, func(ctx *windows.CertContext) (bool, error) {
+		if !bytes.Equal(encodedCert(ctx), s.leaf.Raw) {
+			return false, nil
+		}
+		signature, err = signWithContext(ctx, scheme, digest)
+		return true, err
+	})
+	if err != nil {
+		return nil, err
+	}
+	if signature == nil {
+		return nil, errors.New("certificate is no longer in the personal store")
+	}
+	return signature, nil
+}
+
+func signWithContext(ctx *windows.CertContext, scheme sigScheme, digest []byte) ([]byte, error) {
+	var key uintptr
+	var keySpec uint32
+	var callerFree int32
+	ok, _, err := procCryptAcquireCertificatePrivateKey.Call(uintptr(unsafe.Pointer(ctx)), cryptAcquireSilentFlag|cryptAcquirePreferNCryptKeyFlag, 0,
+		uintptr(unsafe.Pointer(&key)), uintptr(unsafe.Pointer(&keySpec)), uintptr(unsafe.Pointer(&callerFree)))
+	if ok == 0 {
+		return nil, fmt.Errorf("acquire private key: %w", err)
+	}
+	if keySpec != certNCryptKeySpec {
+		if callerFree != 0 {
+			_ = windows.CryptReleaseContext(windows.Handle(key), 0)
+		}
+		return nil, legacyKeyError(keySpec)
+	}
+	if callerFree != 0 {
+		defer func() { _, _, _ = procNCryptFreeObject.Call(key) }()
+	}
+
+	var padding unsafe.Pointer
+	var flags uintptr
+	if scheme == schemeRSAPSSSHA256 {
+		algID, _ := windows.UTF16PtrFromString("SHA256")
+		info := bcryptPSSPaddingInfo{algID: algID, salt: sha256.Size}
+		padding, flags = unsafe.Pointer(&info), bcryptPadPSS
+	}
+	size, err := ncryptSignHash(key, padding, digest, nil, flags)
+	if err != nil {
+		return nil, err
+	}
+	signature := make([]byte, size)
+	if size, err = ncryptSignHash(key, padding, digest, signature, flags); err != nil {
+		return nil, err
+	}
+	signature = signature[:size]
+	if scheme == schemeRSAPSSSHA256 {
+		return signature, nil
+	}
+	return ecdsaSignatureASN1(signature)
+}
+
+// legacyKeyError describes a key acquired through CryptoAPI rather than CNG, naming its
+// key spec and the remedy, since the certificate otherwise looks usable in the store.
+func legacyKeyError(keySpec uint32) error {
+	spec := fmt.Sprintf("key spec %d", keySpec)
+	switch keySpec {
+	case atKeyExchange:
+		spec = "AT_KEYEXCHANGE"
+	case atSignature:
+		spec = "AT_SIGNATURE"
+	}
+	return fmt.Errorf("%w (%s); re-enrol it with a certificate template whose provider is a CNG key storage provider", errLegacyKey, spec)
+}
+
+func ncryptSignHash(key uintptr, padding unsafe.Pointer, digest, signature []byte, flags uintptr) (uint32, error) {
+	var result uint32
+	var signaturePtr uintptr
+	if len(signature) > 0 {
+		signaturePtr = uintptr(unsafe.Pointer(&signature[0]))
+	}
+	status, _, _ := procNCryptSignHash.Call(key, uintptr(padding), uintptr(unsafe.Pointer(&digest[0])), uintptr(len(digest)),
+		signaturePtr, uintptr(len(signature)), uintptr(unsafe.Pointer(&result)), flags)
+	if uint32(status) != 0 {
+		return 0, fmt.Errorf("NCryptSignHash: 0x%08x", uint32(status))
+	}
+	return result, nil
+}
+
+func storeCertificates(location uint32, name string) ([]*x509.Certificate, error) {
+	store, err := openStore(location, name)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = windows.CertCloseStore(store, 0) }()
+
+	var certs []*x509.Certificate
+	err = eachCertificate(store, func(ctx *windows.CertContext) (bool, error) {
+		cert, err := x509.ParseCertificate(bytes.Clone(encodedCert(ctx)))
+		if err != nil {
+			log.Warnf("skipping certificate in %s store: %v", name, err)
+			return false, nil
+		}
+		certs = append(certs, cert)
+		return false, nil
+	})
+	return certs, err
+}
+
+func openStore(location uint32, name string) (windows.Handle, error) {
+	namePtr, err := windows.UTF16PtrFromString(name)
+	if err != nil {
+		return 0, err
+	}
+	flags := location | uint32(windows.CERT_STORE_READONLY_FLAG|windows.CERT_STORE_OPEN_EXISTING_FLAG)
+	store, err := windows.CertOpenStore(windows.CERT_STORE_PROV_SYSTEM, 0, 0, flags, uintptr(unsafe.Pointer(namePtr)))
+	if err != nil {
+		return 0, fmt.Errorf("open %s certificate store: %w", name, err)
+	}
+	return store, nil
+}
+
+func eachCertificate(store windows.Handle, fn func(*windows.CertContext) (bool, error)) error {
+	var ctx *windows.CertContext
+	for {
+		next, err := windows.CertEnumCertificatesInStore(store, ctx)
+		if next == nil {
+			if errors.Is(err, windows.Errno(windows.CRYPT_E_NOT_FOUND)) || errors.Is(err, windows.ERROR_NO_MORE_FILES) {
+				return nil
+			}
+			return fmt.Errorf("enumerate certificates: %w", err)
+		}
+		ctx = next
+		if stop, err := fn(ctx); stop || err != nil {
+			_ = windows.CertFreeCertificateContext(ctx)
+			return err
+		}
+	}
+}
+
+func encodedCert(ctx *windows.CertContext) []byte {
+	return unsafe.Slice(ctx.EncodedCert, ctx.Length)
+}

client/internal/certproof/systemstore_windows_test.go

@@ -0,0 +1,16 @@
+package certproof
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLegacyKeyError_NamesTheKeySpecAndTheRemedy(t *testing.T) {
+	for spec, want := range map[uint32]string{atKeyExchange: "AT_KEYEXCHANGE", atSignature: "AT_SIGNATURE", 7: "key spec 7"} {
+		err := legacyKeyError(spec)
+		assert.ErrorIs(t, err, errLegacyKey, "callers can tell a legacy key from other failures")
+		assert.ErrorContains(t, err, want, "the key spec found is named")
+		assert.ErrorContains(t, err, "key storage provider", "the error says how to fix the enrolment")
+	}
+}

client/internal/conn_mgr.go

@@ -2,6 +2,7 @@ package internal
 
 import (
 	"context"
+	"maps"
 	"os"
 	"strconv"
 	"sync"
@@ -14,6 +15,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/peerstore"
 	"github.com/netbirdio/netbird/route"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 )
 
 // lazyForce is the resolved local decision for lazy connections, layered above the
@@ -34,94 +36,97 @@ const (
 // - Handling connection establishment based on peer signaling
 //
 // The implementation is not thread-safe; it is protected by engine.syncMsgMux.
+// The only exception is ActivatePeer, which is safe for concurrent use so the
+// DNS warm-up path can call it without contending on the engine mutex.
 type ConnMgr struct {
-	peerStore        *peerstore.Store
-	statusRecorder   *peer.Status
-	iface            lazyconn.WGIface
-	force            lazyForce
-	rosenpassEnabled bool
+	peerStore      *peerstore.Store
+	statusRecorder *peer.Status
+	iface          lazyconn.WGIface
+	force          lazyForce
+	// remoteLazyEnabled caches the account-wide lazy feature flag from management.
+	// It is the default for peers that do not carry a per-peer lazy hint.
+	remoteLazyEnabled bool
 
 	lazyConnMgr *manager.Manager
+	// lazyConnMgrMu guards the lazyConnMgr pointer for readers outside the
+	// engine loop (ActivatePeer). Writers hold it in addition to
+	// engine.syncMsgMux; all other reads stay under engine.syncMsgMux only.
+	lazyConnMgrMu sync.RWMutex
+
+	// reconcileRoutedIPs re-applies a peer's routed allowed IPs after its lazy wake endpoint is
+	// (re)armed (Mode A at arm time). Injected by the engine; nil disables the reconcile.
+	reconcileRoutedIPs func(peerKey string) error
+
+	// appliedExcludeList is the exclude set last handed to the lazy manager, kept so an
+	// unchanged set on the next sync skips the O(n) reconciliation.
+	appliedExcludeList map[string]bool
 
 	wg            sync.WaitGroup
 	lazyCtx       context.Context
 	lazyCtxCancel context.CancelFunc
 }
 
+// SetRoutedIPsReconciler injects the callback used to re-apply a peer's routed allowed IPs when
+// its lazy wake endpoint is (re)armed. Must be called before the lazy manager starts.
+func (e *ConnMgr) SetRoutedIPsReconciler(fn func(peerKey string) error) {
+	e.reconcileRoutedIPs = fn
+}
+
 func NewConnMgr(engineConfig *EngineConfig, statusRecorder *peer.Status, peerStore *peerstore.Store, iface lazyconn.WGIface) *ConnMgr {
 	e := &ConnMgr{
-		peerStore:        peerStore,
-		statusRecorder:   statusRecorder,
-		iface:            iface,
-		force:            resolveLazyForce(engineConfig.LazyConnection),
-		rosenpassEnabled: engineConfig.RosenpassEnabled,
+		peerStore:      peerStore,
+		statusRecorder: statusRecorder,
+		iface:          iface,
+		force:          resolveLazyForce(engineConfig.LazyConnection),
 	}
 	return e
 }
 
-// Start initializes the connection manager. It starts the lazy connection manager when a
-// local override forces it on; with no local override it waits for the management feature flag.
+// Start initializes the connection manager. The lazy connection manager always runs so that
+// per-peer lazy defaults (e.g. proxy peers) work even when the account flag is off; the
+// account flag and the local override decide the default lazy state per peer (see
+// PeerLazyDefault). Rosenpass peers stay lazy-capable too: their connections just never idle
+// on their own, since rosenpass rekey traffic keeps them active.
 func (e *ConnMgr) Start(ctx context.Context) {
 	if e.lazyConnMgr != nil {
 		log.Errorf("lazy connection manager is already started")
 		return
 	}
 
-	switch e.force {
-	case lazyForceOff:
-		log.Infof("lazy connection manager is disabled by local override (%s or MDM policy)", lazyconn.EnvLazyConn)
-		e.statusRecorder.UpdateLazyConnection(false)
-		return
-	case lazyForceNone:
-		log.Infof("lazy connection manager is managed by the management feature flag")
-		e.statusRecorder.UpdateLazyConnection(false)
-		return
-	}
-
-	if e.rosenpassEnabled {
-		log.Warnf("rosenpass connection manager is enabled, lazy connection manager will not be started")
-		e.statusRecorder.UpdateLazyConnection(false)
-		return
-	}
-
 	e.initLazyManager(ctx)
-	e.statusRecorder.UpdateLazyConnection(true)
+	e.statusRecorder.UpdateLazyConnection(e.PeerLazyDefault(mgmProto.LazyState_LazyStateDefault))
 }
 
-// UpdatedRemoteFeatureFlag is called when the remote feature flag is updated.
-// If enabled, it initializes the lazy connection manager and start it. Do not need to call Start() again.
-// If disabled, then it closes the lazy connection manager and open the connections to all peers.
-func (e *ConnMgr) UpdatedRemoteFeatureFlag(ctx context.Context, enabled bool) error {
-	// a local override (NB_LAZY_CONN or local config) takes precedence over management
-	if e.force != lazyForceNone {
-		return nil
+// UpdatedRemoteFeatureFlag caches the account-wide lazy feature flag. The manager itself is
+// not started or stopped here; the per-sync exclude-list reconciliation moves normal peers
+// between the lazy and always-active sets when the flag flips.
+func (e *ConnMgr) UpdatedRemoteFeatureFlag(_ context.Context, enabled bool) error {
+	e.remoteLazyEnabled = enabled
+	if e.isStartedWithLazyMgr() {
+		e.statusRecorder.UpdateLazyConnection(e.PeerLazyDefault(mgmProto.LazyState_LazyStateDefault))
+	}
+	return nil
+}
+
+// PeerLazyDefault reports whether a peer should be lazy. The local override
+// (NB_LAZY_CONN/MDM) wins over everything; without a local override the
+// management per-peer state applies (LazyStateLazy/Eager force the decision),
+// and LazyStateDefault follows the account-wide flag.
+func (e *ConnMgr) PeerLazyDefault(state mgmProto.LazyState) bool {
+	switch e.force {
+	case lazyForceOn:
+		return true
+	case lazyForceOff:
+		return false
 	}
 
-	if enabled {
-		// if the lazy connection manager is already started, do not start it again
-		if e.lazyConnMgr != nil {
-			return nil
-		}
-
-		if e.rosenpassEnabled {
-			log.Infof("rosenpass connection manager is enabled, lazy connection manager will not be started")
-			e.statusRecorder.UpdateLazyConnection(false)
-			return nil
-		}
-
-		log.Warnf("lazy connection manager is enabled by management feature flag")
-		e.initLazyManager(ctx)
-		e.statusRecorder.UpdateLazyConnection(true)
-		return e.addPeersToLazyConnManager()
-	} else {
-		if e.lazyConnMgr == nil {
-			e.statusRecorder.UpdateLazyConnection(false)
-			return nil
-		}
-		log.Infof("lazy connection manager is disabled by management feature flag")
-		e.closeManager(ctx)
-		e.statusRecorder.UpdateLazyConnection(false)
-		return nil
+	switch state {
+	case mgmProto.LazyState_LazyStateLazy:
+		return true
+	case mgmProto.LazyState_LazyStateEager:
+		return false
+	default:
+		return e.remoteLazyEnabled
 	}
 }
 
@@ -141,6 +146,13 @@ func (e *ConnMgr) SetExcludeList(ctx context.Context, peerIDs map[string]bool) {
 		return
 	}
 
+	// The exclude set is recomputed every sync but rarely changes; skip the O(n)
+	// store lookups and reconciliation when it matches what was already applied.
+	if maps.Equal(peerIDs, e.appliedExcludeList) {
+		return
+	}
+	e.appliedExcludeList = maps.Clone(peerIDs)
+
 	excludedPeers := make([]lazyconn.PeerConfig, 0, len(peerIDs))
 
 	for peerID := range peerIDs {
@@ -176,12 +188,16 @@ func (e *ConnMgr) SetExcludeList(ctx context.Context, peerIDs map[string]bool) {
 	}
 }
 
-func (e *ConnMgr) AddPeerConn(ctx context.Context, peerKey string, conn *peer.Conn) (exists bool) {
+// AddPeerConn registers a peer connection. permanent requests an always-active connection
+// (the peer belongs to the exclude set: a forwarder, or a peer that is not lazy by policy).
+// Non-permanent peers are handed to the lazy manager. The subsequent SetExcludeList call
+// reconciles membership for existing peers across flag flips.
+func (e *ConnMgr) AddPeerConn(ctx context.Context, peerKey string, conn *peer.Conn, permanent bool) (exists bool) {
 	if success := e.peerStore.AddPeerConn(peerKey, conn); !success {
 		return true
 	}
 
-	if !e.isStartedWithLazyMgr() {
+	if !e.isStartedWithLazyMgr() || permanent {
 		if err := conn.Open(ctx); err != nil {
 			conn.Log.Errorf("failed to open connection: %v", err)
 		}
@@ -238,12 +254,20 @@ func (e *ConnMgr) RemovePeerConn(peerKey string) {
 	conn.Log.Infof("removed peer from lazy conn manager")
 }
 
+// ActivatePeer wakes an idle lazy connection. Unlike the rest of ConnMgr it is
+// safe for concurrent use: the lazy manager pointer is read under lazyConnMgrMu
+// and the manager itself is internally synchronized, so callers outside the
+// engine loop (DNS warm-up) do not need engine.syncMsgMux.
 func (e *ConnMgr) ActivatePeer(ctx context.Context, conn *peer.Conn) {
-	if !e.isStartedWithLazyMgr() {
+	e.lazyConnMgrMu.RLock()
+	lazyConnMgr := e.lazyConnMgr
+	started := lazyConnMgr != nil && e.lazyCtxCancel != nil
+	e.lazyConnMgrMu.RUnlock()
+	if !started {
 		return
 	}
 
-	if found := e.lazyConnMgr.ActivatePeer(conn.GetKey()); found {
+	if found := lazyConnMgr.ActivatePeer(conn.GetKey()); found {
 		if err := conn.Open(ctx); err != nil {
 			conn.Log.Errorf("failed to open connection: %v", err)
 		}
@@ -268,16 +292,26 @@ func (e *ConnMgr) Close() {
 
 	e.lazyCtxCancel()
 	e.wg.Wait()
+
+	e.lazyConnMgrMu.Lock()
 	e.lazyConnMgr = nil
+	e.lazyConnMgrMu.Unlock()
+
+	e.appliedExcludeList = nil
 }
 
 func (e *ConnMgr) initLazyManager(engineCtx context.Context) {
 	cfg := manager.Config{
 		InactivityThreshold: inactivityThresholdEnv(),
+		ReconcileAllowedIPs: e.reconcileRoutedIPs,
 	}
-	e.lazyConnMgr = manager.NewManager(cfg, engineCtx, e.peerStore, e.iface)
 
+	e.lazyConnMgrMu.Lock()
+	e.lazyConnMgr = manager.NewManager(cfg, engineCtx, e.peerStore, e.iface)
 	e.lazyCtx, e.lazyCtxCancel = context.WithCancel(engineCtx)
+	e.lazyConnMgrMu.Unlock()
+
+	e.appliedExcludeList = nil
 
 	e.wg.Add(1)
 	go func() {
@@ -286,43 +320,6 @@ func (e *ConnMgr) initLazyManager(engineCtx context.Context) {
 	}()
 }
 
-func (e *ConnMgr) addPeersToLazyConnManager() error {
-	peers := e.peerStore.PeersPubKey()
-	lazyPeerCfgs := make([]lazyconn.PeerConfig, 0, len(peers))
-	for _, peerID := range peers {
-		var peerConn *peer.Conn
-		var exists bool
-		if peerConn, exists = e.peerStore.PeerConn(peerID); !exists {
-			log.Warnf("failed to find peer conn for peerID: %s", peerID)
-			continue
-		}
-
-		lazyPeerCfg := lazyconn.PeerConfig{
-			PublicKey:  peerID,
-			AllowedIPs: peerConn.WgConfig().AllowedIps,
-			PeerConnID: peerConn.ConnID(),
-			Log:        peerConn.Log,
-		}
-		lazyPeerCfgs = append(lazyPeerCfgs, lazyPeerCfg)
-	}
-
-	return e.lazyConnMgr.AddActivePeers(lazyPeerCfgs)
-}
-
-func (e *ConnMgr) closeManager(ctx context.Context) {
-	if e.lazyConnMgr == nil {
-		return
-	}
-
-	e.lazyCtxCancel()
-	e.wg.Wait()
-	e.lazyConnMgr = nil
-
-	for _, peerID := range e.peerStore.PeersPubKey() {
-		e.peerStore.PeerConnOpen(ctx, peerID)
-	}
-}
-
 func (e *ConnMgr) isStartedWithLazyMgr() bool {
 	return e.lazyConnMgr != nil && e.lazyCtxCancel != nil
 }
@@ -352,11 +349,20 @@ func inactivityThresholdEnv() *time.Duration {
 		return nil
 	}
 
-	parsedMinutes, err := strconv.Atoi(envValue)
-	if err != nil || parsedMinutes <= 0 {
-		return nil
+	// Documented format: a Go duration such as "30m" or "1h".
+	if d, err := time.ParseDuration(envValue); err == nil {
+		if d <= 0 {
+			return nil
+		}
+		return &d
 	}
 
-	d := time.Duration(parsedMinutes) * time.Minute
-	return &d
+	// Backwards compatibility: a bare integer used to be interpreted as minutes.
+	if parsedMinutes, err := strconv.Atoi(envValue); err == nil && parsedMinutes > 0 {
+		d := time.Duration(parsedMinutes) * time.Minute
+		return &d
+	}
+
+	log.Warnf("invalid %s value %q: expected a Go duration such as 30m or 1h", lazyconn.EnvInactivityThreshold, envValue)
+	return nil
 }

client/internal/conn_mgr_test.go

@@ -1,10 +1,22 @@
 package internal
 
 import (
+	"context"
+	"net"
+	"net/netip"
 	"os"
+	"sync"
 	"testing"
+	"time"
 
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/client/internal/peerstore"
+	"github.com/netbirdio/netbird/monotime"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 )
 
 func TestResolveLazyForce(t *testing.T) {
@@ -38,3 +50,180 @@ func TestResolveLazyForce(t *testing.T) {
 		})
 	}
 }
+
+type mockLazyWGIface struct{}
+
+func (mockLazyWGIface) RemovePeer(string) error { return nil }
+func (mockLazyWGIface) UpdatePeer(string, []netip.Prefix, time.Duration, *net.UDPAddr, *wgtypes.Key) error {
+	return nil
+}
+func (mockLazyWGIface) IsUserspaceBind() bool                    { return false }
+func (mockLazyWGIface) Address() wgaddr.Address                  { return wgaddr.Address{} }
+func (mockLazyWGIface) LastActivities() map[string]monotime.Time { return nil }
+func (mockLazyWGIface) MTU() uint16                              { return 1280 }
+
+// TestConnMgr_ActivatePeerConcurrentWithLifecycle exercises ActivatePeer from
+// non-engine goroutines (the DNS warm-up path) racing the manager lifecycle,
+// which stays on the engine loop. Run with -race: it fails if ActivatePeer
+// still requires engine.syncMsgMux for safety.
+func TestConnMgr_ActivatePeerConcurrentWithLifecycle(t *testing.T) {
+	t.Setenv(lazyconn.EnvLazyConn, "on")
+
+	status := peer.NewRecorder("https://mgm")
+	store := peerstore.NewConnStore()
+	connMgr := NewConnMgr(&EngineConfig{}, status, store, mockLazyWGIface{})
+
+	conn := newTestPeerConn(t, "peerA")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	connMgr.Start(ctx)
+
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+	for range 4 {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				select {
+				case <-done:
+					return
+				default:
+					connMgr.ActivatePeer(ctx, conn)
+				}
+			}
+		}()
+	}
+
+	// Let the activators spin against the started manager, then tear it down
+	// underneath them and let them spin against the stopped manager.
+	time.Sleep(100 * time.Millisecond)
+	connMgr.Close()
+	time.Sleep(50 * time.Millisecond)
+
+	close(done)
+	wg.Wait()
+}
+
+func TestInactivityThresholdEnv(t *testing.T) {
+	tests := []struct {
+		name string
+		val  string
+		want *time.Duration
+	}{
+		{name: "unset", val: "", want: nil},
+		{name: "go duration minutes", val: "30m", want: durPtr(30 * time.Minute)},
+		{name: "go duration hours", val: "1h", want: durPtr(time.Hour)},
+		{name: "go duration seconds", val: "90s", want: durPtr(90 * time.Second)},
+		{name: "bare integer is minutes (backwards compat)", val: "5", want: durPtr(5 * time.Minute)},
+		{name: "zero duration", val: "0s", want: nil},
+		{name: "zero integer", val: "0", want: nil},
+		{name: "negative duration", val: "-5m", want: nil},
+		{name: "garbage", val: "abc", want: nil},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(lazyconn.EnvInactivityThreshold, tc.val)
+			got := inactivityThresholdEnv()
+			switch {
+			case tc.want == nil && got != nil:
+				t.Fatalf("want nil, got %v", *got)
+			case tc.want != nil && got == nil:
+				t.Fatalf("want %v, got nil", *tc.want)
+			case tc.want != nil && *got != *tc.want:
+				t.Fatalf("want %v, got %v", *tc.want, *got)
+			}
+		})
+	}
+}
+
+func TestPeerLazyDefault(t *testing.T) {
+	tests := []struct {
+		name          string
+		force         lazyForce
+		remoteEnabled bool
+		state         mgmProto.LazyState
+		want          bool
+	}{
+		{name: "force on wins over eager state", force: lazyForceOn, state: mgmProto.LazyState_LazyStateEager, want: true},
+		{name: "force off wins over lazy state", force: lazyForceOff, remoteEnabled: true, state: mgmProto.LazyState_LazyStateLazy, want: false},
+		{name: "none, default, account off -> active", force: lazyForceNone, state: mgmProto.LazyState_LazyStateDefault, want: false},
+		{name: "none, default, account on -> lazy", force: lazyForceNone, remoteEnabled: true, state: mgmProto.LazyState_LazyStateDefault, want: true},
+		{name: "none, lazy state, account off -> lazy", force: lazyForceNone, state: mgmProto.LazyState_LazyStateLazy, want: true},
+		{name: "none, eager state, account on -> active", force: lazyForceNone, remoteEnabled: true, state: mgmProto.LazyState_LazyStateEager, want: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := &ConnMgr{force: tt.force, remoteLazyEnabled: tt.remoteEnabled}
+			if got := e.PeerLazyDefault(tt.state); got != tt.want {
+				t.Fatalf("PeerLazyDefault(%v) = %v, want %v", tt.state, got, tt.want)
+			}
+		})
+	}
+}
+
+func durPtr(d time.Duration) *time.Duration { return &d }
+
+// TestToExcludedLazyPeers covers the per-peer lazy classification (proxy vs
+// normal, across the force/account-flag matrix). Forwarder-target exclusion is
+// covered by TestToExcludedLazyPeers_ForwardTarget.
+func TestToExcludedLazyPeers(t *testing.T) {
+	const (
+		normalKey = "normal"
+		lazyKey   = "lazy-state"
+		eagerKey  = "eager-state"
+	)
+
+	peers := []*mgmProto.RemotePeerConfig{
+		{WgPubKey: normalKey, AllowedIps: []string{"100.64.0.1/32"}},
+		{WgPubKey: lazyKey, AllowedIps: []string{"100.64.0.2/32"}, LazyState: mgmProto.LazyState_LazyStateLazy},
+		{WgPubKey: eagerKey, AllowedIps: []string{"100.64.0.3/32"}, LazyState: mgmProto.LazyState_LazyStateEager},
+	}
+
+	tests := []struct {
+		name          string
+		force         lazyForce
+		remoteEnabled bool
+		want          map[string]bool
+	}{
+		{
+			name:  "account off: lazy-state peer lazy, normal + eager active",
+			force: lazyForceNone, remoteEnabled: false,
+			want: map[string]bool{normalKey: true, eagerKey: true},
+		},
+		{
+			name:  "account on: only eager-state peer active",
+			force: lazyForceNone, remoteEnabled: true,
+			want: map[string]bool{eagerKey: true},
+		},
+		{
+			name:  "force off: everything active",
+			force: lazyForceOff, remoteEnabled: true,
+			want: map[string]bool{normalKey: true, lazyKey: true, eagerKey: true},
+		},
+		{
+			name:  "force on: nothing active",
+			force: lazyForceOn, remoteEnabled: false,
+			want: map[string]bool{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := &Engine{connMgr: &ConnMgr{force: tt.force, remoteLazyEnabled: tt.remoteEnabled}}
+			got := e.toExcludedLazyPeers(peers)
+
+			if len(got) != len(tt.want) {
+				t.Fatalf("toExcludedLazyPeers() = %v, want %v", got, tt.want)
+			}
+			for k := range tt.want {
+				if !got[k] {
+					t.Fatalf("expected peer %s excluded, got %v", k, got)
+				}
+			}
+		})
+	}
+}

client/internal/connect.go

@@ -26,6 +26,7 @@ import (
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/netstack"
+	"github.com/netbirdio/netbird/client/internal/certproof"
 	"github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
 	"github.com/netbirdio/netbird/client/internal/listener"
@@ -34,9 +35,11 @@ import (
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
+	"github.com/netbirdio/netbird/client/internal/tunnelnotifier"
 	"github.com/netbirdio/netbird/client/internal/updater"
 	"github.com/netbirdio/netbird/client/internal/updater/installer"
 	nbnet "github.com/netbirdio/netbird/client/net"
+	"github.com/netbirdio/netbird/client/netevents"
 	cProto "github.com/netbirdio/netbird/client/proto"
 	"github.com/netbirdio/netbird/client/ssh"
 	sshconfig "github.com/netbirdio/netbird/client/ssh/config"
@@ -69,18 +72,55 @@ type ConnectClient struct {
 	updateManager *updater.Manager
 
 	persistSyncResponse bool
+	// inMemoryState keeps the state manager off disk, for clients that change
+	// nothing on the host that a later run would have to restore.
+	inMemoryState bool
+
+	// netMgr gates every reconnection loop on OS-reported network
+	// availability and sweeps connections on network change.
+	netMgr *netevents.Manager
+
+	profileOwner        string
+	profileOwnerUnknown bool
+}
+
+// ConnectClientOption configures optional ConnectClient behavior.
+type ConnectClientOption func(*ConnectClient)
+
+// WithInMemoryState keeps client state in memory instead of the default state
+// file, so the client neither reads nor writes another installation's state.
+func WithInMemoryState() ConnectClientOption {
+	return func(c *ConnectClient) { c.inMemoryState = true }
+}
+
+// WithNetEvents injects the OS network event handling.
+func WithNetEvents(events *netevents.Manager) ConnectClientOption {
+	return func(c *ConnectClient) { c.netMgr = events }
+}
+
+// WithProfileOwner names the OS account the active profile belongs to, whose own
+// certificate store answers user certificate posture checks.
+func WithProfileOwner(username string) ConnectClientOption {
+	return func(c *ConnectClient) { c.profileOwner = username }
+}
+
+// WithUnknownProfileOwner records that the active profile's owner could not be
+// determined, so no user's certificate store answers certificate posture checks.
+func WithUnknownProfileOwner() ConnectClientOption {
+	return func(c *ConnectClient) { c.profileOwnerUnknown = true }
 }
 
 func NewConnectClient(
 	ctx context.Context,
 	config *profilemanager.Config,
 	statusRecorder *peer.Status,
+	opts ...ConnectClientOption,
 ) *ConnectClient {
 	// Derive the run context here so Stop owns the cancel that unblocks the run
 	// loop. runCancel is set once at construction, so Stop can call it without
 	// racing the run loop's startup. Callers therefore need not cancel before Stop.
 	runCtx, runCancel := context.WithCancel(ctx)
-	return &ConnectClient{
+	c := &ConnectClient{
 		ctx:            runCtx,
 		runCancel:      runCancel,
 		runExited:      make(chan struct{}),
@@ -88,6 +128,10 @@ func NewConnectClient(
 		statusRecorder: statusRecorder,
 		engineMutex:    sync.Mutex{},
 	}
+	for _, opt := range opts {
+		opt(c)
+	}
+	return c
 }
 
 func (c *ConnectClient) SetUpdateManager(um *updater.Manager) {
@@ -112,11 +156,14 @@ func (c *ConnectClient) RunOnAndroid(
 	stateFilePath string,
 	cacheDir string,
 ) error {
+	notifier := tunnelnotifier.New(networkChangeListener, nil)
+	defer notifier.Close()
+
 	// in case of non Android os these variables will be nil
 	mobileDependency := MobileDependency{
 		TunAdapter:            tunAdapter,
 		IFaceDiscover:         iFaceDiscover,
-		NetworkChangeListener: networkChangeListener,
+		NetworkChangeListener: notifier,
 		HostDNSAddresses:      dnsAddresses,
 		DnsReadyListener:      dnsReadyListener,
 		StateFilePath:         stateFilePath,
@@ -136,10 +183,13 @@ func (c *ConnectClient) RunOniOS(
 	// Set GC percent to 5% to reduce memory usage as iOS only allows 50MB of memory for the extension.
 	debug.SetGCPercent(5)
 
+	notifier := tunnelnotifier.New(networkChangeListener, dnsManager)
+	defer notifier.Close()
+
 	mobileDependency := MobileDependency{
 		FileDescriptor:        fileDescriptor,
-		NetworkChangeListener: networkChangeListener,
-		DnsManager:            dnsManager,
+		NetworkChangeListener: notifier,
+		DnsManager:            notifier,
 		StateFilePath:         stateFilePath,
 		TempDir:               cacheDir,
 	}
@@ -217,7 +267,7 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 	wrapErr := state.Wrap
 	myPrivateKey, err := wgtypes.ParseKey(c.config.PrivateKey)
 	if err != nil {
-		log.Errorf("failed parsing Wireguard key %s: [%s]", c.config.PrivateKey, err.Error())
+		log.Errorf("failed parsing Wireguard key: %s", err)
 		return wrapErr(err)
 	}
 
@@ -231,8 +281,15 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		return err
 	}
 
+	// path stays alongside the manager because the engine derives StateDir
+	// from it; an in-memory client leaves it empty.
 	var path string
-	if runtime.GOOS == "ios" || runtime.GOOS == "android" {
+	var stateManager *statemanager.Manager
+	switch {
+	case c.inMemoryState:
+		log.Debugf("client state is kept in memory")
+		stateManager = statemanager.NewInMemory()
+	case runtime.GOOS == "ios" || runtime.GOOS == "android":
 		// On mobile, use the provided state file path directly
 		if !fileExists(mobileDependency.StateFilePath) {
 			if err := createFile(mobileDependency.StateFilePath); err != nil {
@@ -241,11 +298,12 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			}
 		}
 		path = mobileDependency.StateFilePath
-	} else {
+		stateManager = statemanager.New(path)
+	default:
 		sm := profilemanager.NewServiceManager("")
 		path = sm.GetStatePath()
+		stateManager = statemanager.New(path)
 	}
-	stateManager := statemanager.New(path)
 	stateManager.RegisterState(&sshconfig.ShutdownState{})
 
 	if c.updateManager != nil {
@@ -257,13 +315,27 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		log.Errorf("failed to clean up temporary installer file: %v", err)
 	}
 
-	defer c.statusRecorder.ClientStop()
+	defer func() {
+		c.statusRecorder.SetSessionExpiresAt(time.Time{})
+		c.statusRecorder.ClientStop()
+	}()
 	operation := func() error {
 		// if context cancelled we not start new backoff cycle
 		if c.ctx.Err() != nil {
 			return nil
 		}
 
+		if c.updateManager != nil {
+			c.updateManager.ResetMode()
+		}
+
+		// suspend connection attempts while the OS reports no usable network
+		if waited, err := c.netMgr.Wait(c.ctx); err != nil {
+			return nil
+		} else if waited {
+			backOff.Reset()
+		}
+
 		state.Set(StatusConnecting)
 
 		engineCtx, cancel := context.WithCancel(c.ctx)
@@ -275,8 +347,18 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		}()
 
 		log.Debugf("connecting to the Management service %s", c.config.ManagementURL.Host)
-		mgmClient, err := mgm.NewClient(engineCtx, c.config.ManagementURL.Host, myPrivateKey, mgmTlsEnabled)
+		mgmClient, err := mgm.NewClient(engineCtx, c.config.ManagementURL.Host, myPrivateKey, mgmTlsEnabled,
+			mgm.WithNetEvents(c.netMgr))
 		if err != nil {
+			// On daemon shutdown / Down() the parent context is cancelled
+			// and the dial fails with "context canceled". Wrapping that
+			// into state would leave the snapshot stuck at Connecting+err
+			// until the backoff loop wakes up — instead let the operation
+			// return cleanly so the deferred state.Set(StatusIdle) takes
+			// effect on the next iteration.
+			if c.ctx.Err() != nil {
+				return nil
+			}
 			return wrapErr(gstatus.Errorf(codes.FailedPrecondition, "failed connecting to Management Service : %s", err))
 		}
 		mgmNotifier := statusRecorderToMgmConnStateNotifier(c.statusRecorder)
@@ -341,7 +423,7 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		}()
 
 		// with the global Netbird config in hand connect (just a connection, no stream yet) Signal
-		signalClient, err := connectToSignal(engineCtx, loginResp.GetNetbirdConfig(), myPrivateKey)
+		signalClient, err := connectToSignal(engineCtx, loginResp.GetNetbirdConfig(), myPrivateKey, c.netMgr)
 		if err != nil {
 			log.Error(err)
 			return wrapErr(err)
@@ -371,13 +453,16 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			return wrapErr(err)
 		}
 		engineConfig.TempDir = mobileDependency.TempDir
+		engineConfig.CertStore.ProfileOwner = c.profileOwner
+		engineConfig.CertStore.OwnerUnknown = c.profileOwnerUnknown
 		// Leave StateDir empty when there is no state path so a disk-backed
 		// syncstore falls back to os.TempDir() instead of filepath.Dir("") == ".".
 		if path != "" {
 			engineConfig.StateDir = filepath.Dir(path)
 		}
 
-		relayManager := relayClient.NewManager(engineCtx, relayURLs, myPrivateKey.PublicKey().String(), engineConfig.MTU)
+		relayManager := relayClient.NewManager(engineCtx, relayURLs, myPrivateKey.PublicKey().String(), engineConfig.MTU,
+			relayClient.WithNetEvents(c.netMgr))
 		c.statusRecorder.SetRelayMgr(relayManager)
 		if len(relayURLs) > 0 {
 			if token != nil {
@@ -405,6 +490,7 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			UpdateManager:  c.updateManager,
 			ClientMetrics:  c.clientMetrics,
 			MetricsCtx:     c.ctx,
+			NetMgr:         c.netMgr,
 		}, mobileDependency)
 		engine.SetSyncResponsePersistence(c.persistSyncResponse)
 		c.engine = engine
@@ -415,6 +501,10 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			return wrapErr(err)
 		}
 
+		// Seed the session-expiry deadline from the LoginResponse. Subsequent
+		// changes flow in through SyncResponse and are applied in handleSync.
+		engine.ApplySessionDeadline(loginResp.GetSessionExpiresAt())
+
 		log.Infof("Netbird engine started, the IP is: %s", peerConfig.GetAddress())
 		state.Set(StatusConnected)
 
@@ -451,8 +541,22 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 	}
 
 	c.statusRecorder.ClientStart()
+	// Wrap the backoff with c.ctx so Down()/actCancel propagates into the
+	// inter-attempt sleep — otherwise a 15s MaxInterval can keep the retry
+	// loop alive long after the caller asked to give up, leaving the
+	// status stream stuck at Connecting.
 	err = backoff.Retry(operation, backoff.WithContext(backOff, c.ctx))
 	if err != nil {
+		// Once the client context is cancelled backoff.WithContext surfaces the
+		// bare context error, and any attempt torn down mid-flight reports the
+		// same. That cancellation is the caller asking us to stop (Stop, Down or
+		// an engine restart), so exit cleanly instead of handing back a failure
+		// the caller would have to distinguish from a real one.
+		if c.ctx.Err() != nil && errors.Is(err, context.Canceled) {
+			log.Info("exiting client retry loop, context cancelled")
+			return nil
+		}
+
 		log.Debugf("exiting client retry loop due to unrecoverable error: %s", err)
 		if s, ok := gstatus.FromError(err); ok && (s.Code() == codes.PermissionDenied) {
 			state.Set(StatusNeedsLogin)
@@ -587,6 +691,7 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 		RosenpassEnabled:              config.RosenpassEnabled,
 		RosenpassPermissive:           config.RosenpassPermissive,
 		ServerSSHAllowed:              util.ReturnBoolWithDefaultTrue(config.ServerSSHAllowed),
+		RemoteJobsAllowed:             util.ReturnBoolWithDefaultFalse(config.RemoteJobsAllowed),
 		EnableSSHRoot:                 config.EnableSSHRoot,
 		EnableSSHSFTP:                 config.EnableSSHSFTP,
 		EnableSSHLocalPortForwarding:  config.EnableSSHLocalPortForwarding,
@@ -601,9 +706,12 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 		BlockLANAccess:      config.BlockLANAccess,
 		BlockInbound:        config.BlockInbound,
 		DisableIPv6:         config.DisableIPv6,
+		SyncMessageVersion:  config.SyncMessageVersion,
 
 		LazyConnection: lazyconn.ParseState(config.LazyConnection),
 
+		CertStore: certStoreConfig(config),
+
 		MTU:     selectMTU(config.MTU, peerConfig.Mtu),
 		LogPath: logPath,
 
@@ -630,6 +738,22 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 	return engineConf, nil
 }
 
+// certStoreConfig reads where certificate posture finds certificates from the daemon's
+// environment, NB_CERT_STORE_DIR and NB_CERT_PKCS11_URI with NB_TPM_PIN. The profile
+// config fields that once held them are ignored, and a value left there is reported
+// once, so a setup relying on it does not silently stop proving.
+func certStoreConfig(config *profilemanager.Config) certproof.Config {
+	if config.CertStoreDir != "" || config.CertPKCS11URI != "" {
+		legacyCertConfigOnce.Do(func() {
+			log.Warnf("certificate posture: CertStoreDir and CertPKCS11URI in the profile config are ignored, set %s and %s in the daemon's environment instead",
+				certproof.StoreDirEnv, certproof.PKCS11URIEnv)
+		})
+	}
+	return certproof.Config{PKCS11: certproof.PKCS11FromEnv()}
+}
+
+var legacyCertConfigOnce sync.Once
+
 func selectMTU(localMTU uint16, peerMTU int32) uint16 {
 	var finalMTU uint16 = iface.DefaultMTU
 	if localMTU > 0 {
@@ -645,7 +769,7 @@ func selectMTU(localMTU uint16, peerMTU int32) uint16 {
 }
 
 // connectToSignal creates Signal Service client and established a connection
-func connectToSignal(ctx context.Context, wtConfig *mgmProto.NetbirdConfig, ourPrivateKey wgtypes.Key) (*signal.GrpcClient, error) {
+func connectToSignal(ctx context.Context, wtConfig *mgmProto.NetbirdConfig, ourPrivateKey wgtypes.Key, netMgr *netevents.Manager) (*signal.GrpcClient, error) {
 	var sigTLSEnabled bool
 	if wtConfig.Signal.Protocol == mgmProto.HostConfig_HTTPS {
 		sigTLSEnabled = true
@@ -653,7 +777,8 @@ func connectToSignal(ctx context.Context, wtConfig *mgmProto.NetbirdConfig, ourP
 		sigTLSEnabled = false
 	}
 
-	signalClient, err := signal.NewClient(ctx, wtConfig.Signal.Uri, ourPrivateKey, sigTLSEnabled)
+	signalClient, err := signal.NewClient(ctx, wtConfig.Signal.Uri, ourPrivateKey, sigTLSEnabled,
+		signal.WithNetEvents(netMgr))
 	if err != nil {
 		log.Errorf("error while connecting to the Signal Exchange Service %s: %s", wtConfig.Signal.Uri, err)
 		return nil, gstatus.Errorf(codes.FailedPrecondition, "failed connecting to Signal Service : %s", err)
@@ -676,11 +801,13 @@ func loginToManagement(ctx context.Context, client mgm.Client, pubSSHKey []byte,
 		config.BlockLANAccess,
 		config.BlockInbound,
 		config.DisableIPv6,
+		config.SyncMessageVersion,
 		config.EnableSSHRoot,
 		config.EnableSSHSFTP,
 		config.EnableSSHLocalPortForwarding,
 		config.EnableSSHRemotePortForwarding,
 		config.DisableSSHAuth,
+		config.RemoteJobsAllowed,
 	)
 	return client.Login(sysInfo, pubSSHKey, config.DNSLabels)
 }

client/internal/connect_certstore_test.go

@@ -0,0 +1,26 @@
+package internal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/netbirdio/netbird/client/internal/certproof"
+	"github.com/netbirdio/netbird/client/internal/profilemanager"
+)
+
+// TestCertStoreConfig_ReadsEnvironmentNotProfile: the token URI may carry the PIN, so it
+// and the store directory come from the daemon's environment, and values left in the
+// profile config from an older version are ignored.
+func TestCertStoreConfig_ReadsEnvironmentNotProfile(t *testing.T) {
+	t.Setenv(certproof.PKCS11URIEnv, "pkcs11:token=env")
+	t.Setenv(certproof.PINEnv, "1234")
+
+	cfg := certStoreConfig(&profilemanager.Config{
+		CertStoreDir:  "/from/profile",
+		CertPKCS11URI: "pkcs11:token=profile?pin-value=9999",
+	})
+
+	assert.Equal(t, "pkcs11:token=env", cfg.PKCS11.URI, "the URI comes from the environment")
+	assert.Equal(t, "1234", cfg.PKCS11.PIN, "the PIN comes from the environment")
+}

client/internal/connect_test.go

@@ -5,65 +5,78 @@ import (
 	"testing"
 )
 
-func Test_freePort(t *testing.T) {
-	tests := []struct {
-		name        string
-		port        int
-		want        int
-		shouldMatch bool
-	}{
-		{
-			name:        "when port is 0 use random port",
-			port:        0,
-			want:        0,
-			shouldMatch: false,
-		},
-		{
-			name:        "provided and available",
-			port:        51821,
-			want:        51821,
-			shouldMatch: true,
-		},
-		{
-			name:        "provided and not available",
-			port:        51830,
-			want:        51830,
-			shouldMatch: false,
-		},
-	}
-	c1, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
+// probeFreePort asks the OS for a free UDP port and immediately releases it.
+// The returned number is only a hint: nothing stops another process from
+// grabbing the same port before the caller gets a chance to bind it.
+//
+// A hardcoded port number is not an option here: any fixed number can fall
+// inside the ephemeral range and be held by an unrelated process on the test
+// runner.
+func probeFreePort(t *testing.T) int {
+	t.Helper()
+
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
 	if err != nil {
-		t.Errorf("freePort error = %v", err)
+		t.Fatalf("failed to bind probe port: %v", err)
 	}
-	defer func(c1 *net.UDPConn) {
-		_ = c1.Close()
-	}(c1)
-
-	if tests[1].port == c1.LocalAddr().(*net.UDPAddr).Port {
-		tests[1].port++
-		tests[1].want++
-	}
-
-	tests[2].port = c1.LocalAddr().(*net.UDPAddr).Port
-	tests[2].want = c1.LocalAddr().(*net.UDPAddr).Port
-
-	for _, tt := range tests {
-
-		t.Run(tt.name, func(t *testing.T) {
-			got, err := freePort(tt.port)
-
-			if err != nil {
-				t.Errorf("got an error while getting free port: %v", err)
-			}
-
-			if tt.shouldMatch && got != tt.want {
-				t.Errorf("got a different port %v, want %v", got, tt.want)
-			}
-
-			if !tt.shouldMatch && got == tt.want {
-				t.Errorf("got the same port %v, want a different port", tt.want)
-			}
-		})
-
+	port := conn.LocalAddr().(*net.UDPAddr).Port
+	if err := conn.Close(); err != nil {
+		t.Fatalf("failed to close probe port: %v", err)
 	}
+	return port
+}
+
+func Test_freePort(t *testing.T) {
+	t.Run("when port is 0 use random port", func(t *testing.T) {
+		got, err := freePort(0)
+		if err != nil {
+			t.Fatalf("got an error while getting free port: %v", err)
+		}
+		if got == 0 {
+			t.Errorf("got port 0, want a non-zero random port")
+		}
+	})
+
+	t.Run("provided and available", func(t *testing.T) {
+		const maxAttempts = 5
+
+		// The probed port is released before freePort binds it, so an
+		// unrelated process on the test runner can grab it in between,
+		// making freePort fall back to a different port. Retry with a
+		// freshly probed port instead of failing on a lost race.
+		for attempt := 1; attempt <= maxAttempts; attempt++ {
+			candidate := probeFreePort(t)
+
+			got, err := freePort(candidate)
+			if err != nil {
+				t.Fatalf("got an error while getting free port: %v", err)
+			}
+
+			if got == candidate {
+				return
+			}
+			t.Logf("attempt %d: freePort returned %d instead of the requested %d, retrying", attempt, got, candidate)
+		}
+
+		t.Fatalf("freePort did not return the requested free port after %d attempts", maxAttempts)
+	})
+
+	t.Run("provided and not available", func(t *testing.T) {
+		busy, err := net.ListenUDP("udp", &net.UDPAddr{Port: 0})
+		if err != nil {
+			t.Fatalf("failed to bind busy port: %v", err)
+		}
+		t.Cleanup(func() {
+			_ = busy.Close()
+		})
+		busyPort := busy.LocalAddr().(*net.UDPAddr).Port
+
+		got, err := freePort(busyPort)
+		if err != nil {
+			t.Fatalf("got an error while getting free port: %v", err)
+		}
+		if got == busyPort {
+			t.Errorf("got the same port %v, want a different port", busyPort)
+		}
+	})
 }

client/internal/daemonaddr/grpc.go

@@ -0,0 +1,42 @@
+package daemonaddr
+
+import (
+	"os"
+	"strconv"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	// EnvMaxRecvMsgSize overrides the default gRPC max receive message size for
+	// connections to the daemon. Value is in bytes.
+	EnvMaxRecvMsgSize = "NB_DAEMON_GRPC_MAX_MSG_SIZE"
+
+	// defaultMaxRecvMsgSize is the max gRPC receive message size used for daemon
+	// connections when EnvMaxRecvMsgSize is unset or invalid. It overrides the
+	// gRPC library default of 4 MB, which a detailed status already exceeds on a
+	// network of a few thousand peers.
+	defaultMaxRecvMsgSize = 1024 * 1024 * 16
+)
+
+// MaxRecvMsgSize returns the max gRPC receive message size for daemon connections
+// from the environment, or defaultMaxRecvMsgSize (16 MB) if unset or invalid.
+func MaxRecvMsgSize() int {
+	val := os.Getenv(EnvMaxRecvMsgSize)
+	if val == "" {
+		return defaultMaxRecvMsgSize
+	}
+
+	size, err := strconv.Atoi(val)
+	if err != nil {
+		log.Warnf("invalid %s value %q, using default: %v", EnvMaxRecvMsgSize, val, err)
+		return defaultMaxRecvMsgSize
+	}
+
+	if size <= 0 {
+		log.Warnf("invalid %s value %d, must be positive, using default", EnvMaxRecvMsgSize, size)
+		return defaultMaxRecvMsgSize
+	}
+
+	return size
+}

client/internal/daemonaddr/grpc_test.go

@@ -0,0 +1,112 @@
+package daemonaddr
+
+import (
+	"context"
+	"net"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/proto"
+)
+
+func TestMaxRecvMsgSize(t *testing.T) {
+	tests := []struct {
+		name     string
+		envValue string
+		expected int
+	}{
+		{name: "unset returns default", envValue: "", expected: defaultMaxRecvMsgSize},
+		{name: "non-numeric returns default", envValue: "abc", expected: defaultMaxRecvMsgSize},
+		{name: "negative returns default", envValue: "-1", expected: defaultMaxRecvMsgSize},
+		{name: "zero returns default", envValue: "0", expected: defaultMaxRecvMsgSize},
+		{name: "valid value is used", envValue: "33554432", expected: 33554432},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set first so the previous value is restored on cleanup, then unset to
+			// exercise the absent case.
+			t.Setenv(EnvMaxRecvMsgSize, tc.envValue)
+			if tc.envValue == "" {
+				require.NoError(t, os.Unsetenv(EnvMaxRecvMsgSize), "unset the override")
+			}
+
+			assert.Equal(t, tc.expected, MaxRecvMsgSize(), "max receive message size")
+		})
+	}
+}
+
+// bigStatusServer answers Status with a response larger than gRPC's 4 MB default
+// receive limit, which is what a detailed status on a large network looks like.
+type bigStatusServer struct {
+	proto.UnimplementedDaemonServiceServer
+	payload string
+}
+
+func (s *bigStatusServer) Status(context.Context, *proto.StatusRequest) (*proto.StatusResponse, error) {
+	return &proto.StatusResponse{Status: s.payload}, nil
+}
+
+func startBigStatusServer(t *testing.T, payload string) string {
+	t.Helper()
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err, "listen on loopback")
+
+	srv := grpc.NewServer()
+	proto.RegisterDaemonServiceServer(srv, &bigStatusServer{payload: payload})
+	go func() {
+		_ = srv.Serve(listener)
+	}()
+	t.Cleanup(srv.Stop)
+
+	return "tcp://" + listener.Addr().String()
+}
+
+func TestDialTargetAcceptsAStatusOverTheGrpcDefault(t *testing.T) {
+	payload := strings.Repeat("x", 5*1024*1024)
+	addr := startBigStatusServer(t, payload)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	target, opts := DialTarget(addr)
+	conn, err := grpc.NewClient(target, opts...)
+	require.NoError(t, err, "dial the daemon")
+	t.Cleanup(func() { _ = conn.Close() })
+
+	resp, err := proto.NewDaemonServiceClient(conn).Status(ctx, &proto.StatusRequest{})
+	require.NoError(t, err, "a detailed status must not be rejected for its size")
+	assert.Len(t, resp.GetStatus(), len(payload), "the whole response must arrive")
+}
+
+// TestDialTargetRaisesTheDefaultLimit is the negative control: the same response
+// over a connection carrying gRPC's own defaults is refused, which is the failure
+// reported by `netbird status -d` on a large deployment.
+func TestDialTargetRaisesTheDefaultLimit(t *testing.T) {
+	payload := strings.Repeat("x", 5*1024*1024)
+	addr := startBigStatusServer(t, payload)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	conn, err := grpc.NewClient(
+		strings.TrimPrefix(addr, "tcp://"),
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+	)
+	require.NoError(t, err, "dial with the library defaults")
+	t.Cleanup(func() { _ = conn.Close() })
+
+	_, err = proto.NewDaemonServiceClient(conn).Status(ctx, &proto.StatusRequest{})
+	require.Error(t, err, "the library default must reject this response")
+	assert.Equal(t, codes.ResourceExhausted, status.Code(err), "gRPC rejects an oversized message")
+}

client/internal/daemonaddr/identity.go

@@ -0,0 +1,17 @@
+package daemonaddr
+
+import "strings"
+
+// CarriesIdentity reports whether the control channel at addr conveys the
+// connecting process's identity to the daemon. A Unix socket carries peer
+// credentials and a named pipe carries the client's token. Nothing else does, TCP
+// included, and there the daemon can authorize a privileged operation for nobody
+// at all: see ResolveDaemonAddr, which says as much to anyone still reaching the
+// Windows daemon on the address it served before it had a pipe.
+//
+// A client uses this to tell whether becoming privileged would get it anywhere.
+// It answers from the scheme and nothing else, so an address it does not
+// recognise counts as carrying no identity.
+func CarriesIdentity(addr string) bool {
+	return strings.HasPrefix(addr, "unix://") || strings.HasPrefix(addr, pipeScheme)
+}

client/internal/daemonaddr/identity_test.go

@@ -0,0 +1,29 @@
+package daemonaddr
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCarriesIdentity(t *testing.T) {
+	tests := []struct {
+		addr string
+		want bool
+	}{
+		{"unix:///var/run/netbird.sock", true},
+		{"unix:///var/run/netbird/default.sock", true},
+		{"npipe://netbird", true},
+		{`npipe://\\.\pipe\ProtectedPrefix\Administrators\netbird`, true},
+		{"tcp://127.0.0.1:41731", false},
+		{"tcp://localhost:41731", false},
+		{"", false},
+		{"/var/run/netbird.sock", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.addr, func(t *testing.T) {
+			assert.Equal(t, tt.want, CarriesIdentity(tt.addr), "address %q", tt.addr)
+		})
+	}
+}

client/internal/daemonaddr/owner.go

@@ -0,0 +1,15 @@
+package daemonaddr
+
+// DaemonRunsAsSelf reports whether the daemon listening at addr runs as this very
+// user. That is what makes an unprivileged daemon authorize this process for the
+// changes it otherwise restricts to root or an administrator, so a client can tell
+// up front whether those controls are usable instead of letting a save fail.
+//
+// It is answered from the ownership of the socket or pipe the daemon created, so it
+// costs no round trip and needs no cooperation from the daemon. Ownership that
+// cannot be read is reported as false, including for a TCP address, so a caller
+// reading this as "the daemon would allow it" fails closed. The daemon remains the
+// only thing that authorizes anything: this only decides what a client offers.
+func DaemonRunsAsSelf(addr string) bool {
+	return daemonRunsAsSelf(addr)
+}

client/internal/daemonaddr/owner_unix.go

@@ -0,0 +1,40 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"os"
+	"strings"
+	"syscall"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// daemonRunsAsSelf compares the owner of the daemon's Unix socket with this
+// process's uid. Root is not treated specially here: a root caller is privileged
+// on its own merits, and a root-owned socket says nothing about the caller.
+func daemonRunsAsSelf(addr string) bool {
+	path, ok := strings.CutPrefix(addr, "unix://")
+	if !ok {
+		return false
+	}
+
+	info, err := os.Stat(path)
+	if err != nil {
+		log.Debugf("stat daemon socket %s: %v", path, err)
+		return false
+	}
+
+	// Only a socket says anything about a daemon. A directory or a leftover
+	// regular file at that path is not one, and reading it as "the daemon runs as
+	// us" would offer controls the daemon then refuses.
+	if info.Mode()&os.ModeSocket == 0 {
+		return false
+	}
+
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return false
+	}
+	return stat.Uid == uint32(os.Getuid())
+}

client/internal/daemonaddr/owner_unix_test.go

@@ -0,0 +1,62 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"net"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// A socket this user created means the daemon runs as this user, which is the
+// rootless case where the daemon delegates its authority to its own identity.
+func TestDaemonRunsAsSelf_OwnSocket(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "netbird.sock")
+	ln, err := net.Listen("unix", path)
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := ln.Close(); err != nil {
+			t.Logf("close listener: %v", err)
+		}
+	})
+
+	if !DaemonRunsAsSelf("unix://" + path) {
+		t.Error("a socket owned by this user must count as the daemon running as us")
+	}
+}
+
+// Everything that is not a readable socket of ours has to answer false, because
+// the caller reads a true as "the daemon would authorize me".
+func TestDaemonRunsAsSelf_FailsClosed(t *testing.T) {
+	dir := t.TempDir()
+
+	// A socket owned by another user, which is what a root-run daemon looks like
+	// to an unprivileged client. Only assertable when we are not root ourselves.
+	rootOwned := "unix:///var/run/netbird.sock"
+	if _, err := os.Stat("/var/run/netbird.sock"); err == nil && os.Getuid() != 0 {
+		if DaemonRunsAsSelf(rootOwned) {
+			t.Error("a socket owned by another user must not count as ours")
+		}
+	}
+
+	for name, addr := range map[string]string{
+		"missing socket":  "unix://" + filepath.Join(dir, "absent.sock"),
+		"tcp address":     "tcp://127.0.0.1:41731",
+		"named pipe":      "npipe://netbird",
+		"empty":           "",
+		"no scheme":       filepath.Join(dir, "absent.sock"),
+		"directory":       "unix://" + dir,
+		"unknown scheme":  "http://localhost:8080",
+		"scheme only":     "unix://",
+		"relative socket": "unix://netbird.sock",
+	} {
+		t.Run(name, func(t *testing.T) {
+			if DaemonRunsAsSelf(addr) {
+				t.Errorf("%q must not count as a daemon running as us", addr)
+			}
+		})
+	}
+}

client/internal/daemonaddr/owner_windows.go

@@ -0,0 +1,42 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"context"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// daemonRunsAsSelf reads the owner of the daemon's pipe. A daemon running as the
+// service account owns its pipe as LocalSystem, and an elevated one as
+// BUILTIN\Administrators, so only a daemon the user started themselves matches.
+func daemonRunsAsSelf(addr string) bool {
+	name, ok := strings.CutPrefix(addr, pipeScheme)
+	if !ok {
+		return false
+	}
+
+	for _, path := range PipePaths(name) {
+		// Bounded: this runs on the UI's path for deciding which controls to
+		// offer, so a pipe that does not answer promptly must not stall it. A
+		// timeout leaves the caller unprivileged, which only disables controls.
+		ctx, cancel := context.WithTimeout(context.Background(), probeTimeout)
+		conn, err := dialPipe(ctx, path)
+		cancel()
+		if err != nil {
+			continue
+		}
+
+		owned := ipcauth.PipeOwnedBySelf(conn)
+		if cerr := conn.Close(); cerr != nil {
+			log.Debugf("close daemon pipe %s after ownership check: %v", path, cerr)
+		}
+		return owned
+	}
+
+	return false
+}

client/internal/daemonaddr/pipe.go

@@ -0,0 +1,106 @@
+package daemonaddr
+
+import (
+	"context"
+	"net"
+	"runtime"
+	"strings"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+const (
+	// WindowsPipeAddr is the default daemon address on Windows. A named pipe
+	// carries the connecting process's token, which loopback TCP does not, so
+	// it is the only Windows transport on which the daemon can tell who is
+	// calling it.
+	WindowsPipeAddr = "npipe://netbird"
+
+	// legacyWindowsAddr is the loopback-TCP address the Windows daemon used
+	// before named-pipe support.
+	legacyWindowsAddr = "tcp://127.0.0.1:41731"
+
+	pipeScheme = "npipe://"
+
+	// protectedPrefix is the NPFS namespace in which only LocalSystem and
+	// members of BUILTIN\Administrators may create a pipe. A daemon running as
+	// the service account creates its pipe there so that an unprivileged process
+	// cannot pre-create the name, which would keep the daemon from starting and
+	// leave callers talking to the squatter. Opening such a pipe needs no
+	// privilege, so unprivileged clients still reach the daemon.
+	protectedPrefix = `ProtectedPrefix\Administrators\`
+)
+
+// DialTarget returns the gRPC dial target and transport options for a daemon
+// address. The npipe scheme needs a context dialer because gRPC has no
+// named-pipe resolver; unix and tcp are handled by gRPC itself.
+func DialTarget(addr string) (string, []grpc.DialOption) {
+	opts := []grpc.DialOption{
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithDefaultCallOptions(grpc.MaxCallRecvMsgSize(MaxRecvMsgSize())),
+	}
+
+	if name, ok := strings.CutPrefix(addr, pipeScheme); ok {
+		paths := PipePaths(name)
+		opts = append(opts, grpc.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
+			return dialPipePaths(ctx, paths)
+		}))
+		return "passthrough:///netbird-daemon-pipe", opts
+	}
+
+	return strings.TrimPrefix(addr, "tcp://"), opts
+}
+
+// PipePath maps an npipe address name ("netbird", from "npipe://netbird") to a
+// Windows named-pipe path (\\.\pipe\netbird). A fully qualified path is left as
+// is.
+func PipePath(name string) string {
+	if strings.HasPrefix(name, `\\`) {
+		return name
+	}
+	return `\\.\pipe\` + name
+}
+
+// PipePaths returns the paths a daemon control pipe may live at for an npipe
+// address name, in the order both sides must try them: the protected name first,
+// then the plain one.
+//
+// The daemon serves the first it can create, which is the protected name when it
+// runs as the service account and the plain one when it runs as an ordinary user,
+// as it does in netstack mode. Clients therefore have to try both, and because a
+// client cannot tell from the name alone who created the pipe, the plain name is
+// only usable once the server's identity has been checked: see
+// verifyPipeServer.
+//
+// A fully qualified path is what the operator asked for and is used as is.
+func PipePaths(name string) []string {
+	if strings.HasPrefix(name, `\\`) {
+		return []string{name}
+	}
+	return []string{PipePath(protectedPrefix + name), PipePath(name)}
+}
+
+// IsProtectedPipePath reports whether a pipe path is in the namespace only an
+// administrator or LocalSystem can create in, which is what lets a client trust
+// such a pipe from its name alone.
+func IsProtectedPipePath(path string) bool {
+	return strings.HasPrefix(path, `\\.\pipe\`+protectedPrefix)
+}
+
+// MigrateLegacy upgrades the pre-named-pipe Windows daemon address to the named
+// pipe, reporting whether it rewrote the address. Existing installs persist the
+// daemon address, so without this an upgraded daemon would keep listening on
+// loopback TCP, where callers carry no identity and privileged operations would
+// have to be refused for everyone. Only the exact legacy default is rewritten:
+// a deliberately chosen custom address is left alone.
+func MigrateLegacy(addr string) (string, bool) {
+	return migrateLegacyForOS(runtime.GOOS, addr)
+}
+
+func migrateLegacyForOS(goos, addr string) (string, bool) {
+	if goos == "windows" && addr == legacyWindowsAddr {
+		return WindowsPipeAddr, true
+	}
+	return addr, false
+}

client/internal/daemonaddr/pipe_other.go

@@ -0,0 +1,15 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"context"
+	"fmt"
+	"net"
+)
+
+// dialPipePaths is Windows-only: no other platform serves the daemon on a named
+// pipe.
+func dialPipePaths(context.Context, []string) (net.Conn, error) {
+	return nil, fmt.Errorf("named pipes are only supported on Windows")
+}

client/internal/daemonaddr/pipe_test.go

@@ -0,0 +1,30 @@
+package daemonaddr
+
+import (
+	"slices"
+	"testing"
+)
+
+// The protected name must be tried before the plain one on both sides: it is the
+// one an unprivileged process cannot create, so preferring it is what keeps a
+// squatter from owning the name the service daemon would otherwise use.
+func TestPipePaths_PrefersTheProtectedName(t *testing.T) {
+	got := PipePaths("netbird")
+	want := []string{
+		`\\.\pipe\ProtectedPrefix\Administrators\netbird`,
+		`\\.\pipe\netbird`,
+	}
+	if !slices.Equal(got, want) {
+		t.Errorf("PipePaths = %q, want %q", got, want)
+	}
+}
+
+// An operator who passes a full path chose exactly one pipe, so neither side may
+// look anywhere else.
+func TestPipePaths_QualifiedPathIsUsedAsIs(t *testing.T) {
+	path := `\\.\pipe\custom-netbird`
+	got := PipePaths(path)
+	if !slices.Equal(got, []string{path}) {
+		t.Errorf("PipePaths = %q, want just %q", got, path)
+	}
+}

client/internal/daemonaddr/pipe_windows.go

@@ -0,0 +1,59 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// dialPipePaths connects to the first path that answers with a pipe server this
+// client may trust, and returns the last error when none does.
+func dialPipePaths(ctx context.Context, paths []string) (net.Conn, error) {
+	var lastErr error
+	for _, path := range paths {
+		conn, err := dialPipe(ctx, path)
+		if err != nil {
+			log.Debugf("dial daemon pipe %s: %v", path, err)
+			lastErr = err
+			continue
+		}
+
+		// A pipe in the protected namespace could only have been created by an
+		// administrator or LocalSystem, so its name is the guarantee. Any other
+		// name has to be checked, because any local user can create one.
+		if !IsProtectedPipePath(path) {
+			if err := ipcauth.PipeServerTrusted(conn); err != nil {
+				if closeErr := conn.Close(); closeErr != nil {
+					log.Debugf("close untrusted pipe %s: %v", path, closeErr)
+				}
+				lastErr = fmt.Errorf("%s: %w", path, err)
+				continue
+			}
+		}
+
+		return conn, nil
+	}
+
+	if lastErr == nil {
+		lastErr = errors.New("no daemon pipe to connect to")
+	}
+	return nil, lastErr
+}
+
+// dialPipe connects to the daemon control pipe at SECURITY_IDENTIFICATION.
+// winio's plain DialPipe connects at SECURITY_ANONYMOUS, under which the daemon
+// cannot read the caller's token at all. Identification lets the daemon read the
+// caller's SID and groups without granting it the ability to act as the caller.
+func dialPipe(ctx context.Context, path string) (net.Conn, error) {
+	access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE)
+	return winio.DialPipeAccessImpLevel(ctx, path, access, winio.PipeImpLevelIdentification)
+}

client/internal/daemonaddr/resolve_pipe_other.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package daemonaddr
+
+// ResolveDaemonAddr is a no-op off Windows, where there is no named-pipe
+// default to fall back from.
+func ResolveDaemonAddr(addr string) string {
+	return addr
+}

client/internal/daemonaddr/resolve_pipe_windows.go

@@ -0,0 +1,82 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"net"
+	"strings"
+	"time"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+)
+
+// probeTimeout bounds each transport probe. Both are local, so a daemon that is
+// listening answers immediately and one that is not fails immediately.
+const probeTimeout = 300 * time.Millisecond
+
+// ResolveDaemonAddr keeps a client on the named pipe and never silently moves it
+// off. When the pipe does not answer it checks the legacy loopback TCP address, so
+// a client meeting a daemon that has not restarted since the upgrade can say what
+// is wrong, but it does not connect there.
+//
+// Using that address automatically would be a downgrade the user never asked for:
+// any local process can bind 127.0.0.1 while the daemon is not listening, and the
+// transport carries no caller identity, so a client that accepted whatever answered
+// would hand a setup key, a pre-shared key or an SSO prompt to a local impostor. An
+// operator who needs the legacy address during the upgrade window can still pass
+// --daemon-addr explicitly, which is a deliberate choice and still refuses the
+// privileged operations.
+//
+// Only the pipe address is resolved. A custom address is left alone, though passing
+// --daemon-addr npipe://netbird explicitly is indistinguishable from the default
+// here, so it is treated the same way.
+func ResolveDaemonAddr(addr string) string {
+	if addr != WindowsPipeAddr {
+		return addr
+	}
+
+	for _, path := range PipePaths("netbird") {
+		if pipeAvailable(path) {
+			return addr
+		}
+	}
+
+	if tcpAvailable(legacyWindowsAddr) {
+		log.Warnf("the daemon is not serving %s, but something is listening on the legacy %s. "+
+			"Restart the NetBird service so it serves the pipe. That address is not used automatically: "+
+			"any local user can bind it and it carries no caller identity, so pass --daemon-addr %s "+
+			"explicitly if you accept that",
+			WindowsPipeAddr, legacyWindowsAddr, legacyWindowsAddr)
+	}
+
+	return addr
+}
+
+func pipeAvailable(path string) bool {
+	timeout := probeTimeout
+	conn, err := winio.DialPipe(path, &timeout)
+	if err != nil {
+		return false
+	}
+	if err := conn.Close(); err != nil {
+		log.Debugf("close daemon pipe probe: %v", err)
+	}
+	return true
+}
+
+func tcpAvailable(addr string) bool {
+	host := addr
+	if _, after, ok := strings.Cut(addr, "://"); ok {
+		host = after
+	}
+
+	conn, err := net.DialTimeout("tcp", host, probeTimeout)
+	if err != nil {
+		return false
+	}
+	if err := conn.Close(); err != nil {
+		log.Debugf("close daemon TCP probe: %v", err)
+	}
+	return true
+}

client/internal/debug/debug.go

@@ -34,9 +34,8 @@ import (
 	"github.com/netbirdio/netbird/shared/netiputil"
 )
 
-const readmeContent = `Netbird debug bundle
-This debug bundle contains the following files.
-If the --anonymize flag is set, the files are anonymized to protect sensitive information.
+const readmeContent = `This debug bundle contains the following files.
+If anonymization is enabled (--anonymize / --anonymize-level), the files are anonymized to protect sensitive information.
 
 status.txt: Anonymized status information of the NetBird client.
 client.log: Most recent, anonymized client log file of the NetBird client.
@@ -52,6 +51,7 @@ nftables.txt: Anonymized nftables rules with packet counters across all families
 sysctls.txt: Forwarding, reverse-path filter, source-validation, and conntrack accounting sysctl values that the NetBird client may read or modify, if --system-info flag was provided (Linux only).
 resolv.conf: DNS resolver configuration from /etc/resolv.conf (Unix systems only), if --system-info flag was provided.
 scutil_dns.txt: DNS configuration from scutil --dns (macOS only), if --system-info flag was provided.
+dns_windows.txt: Anonymized NRPT rules and policy table in effect, DNS client policy, and per-interface and per-adapter DNS configuration (Windows only), if --system-info flag was provided.
 resolved_domains.txt: Anonymized resolved domain IP addresses from the status recorder.
 config.txt: Anonymized configuration information of the NetBird client.
 network_map.json: Anonymized sync response containing peer configurations, routes, DNS settings, and firewall rules.
@@ -70,21 +70,34 @@ capture.pcap: Packet capture in pcap format. Only present when capture was runni
 
 
 Anonymization Process
-The files in this bundle have been anonymized to protect sensitive information. Here's how the anonymization was applied:
+The files in this bundle have been anonymized to protect sensitive information. The level applied to this bundle is recorded at the top of this file. Here's how the anonymization was applied:
 
 IP Addresses
 
-IPv4 addresses are replaced with addresses starting from 198.51.100.0
-IPv6 addresses are replaced with addresses starting from 100::
+Default level:
+- Public IPv4 addresses are replaced with addresses starting from 198.51.100.0
+- Public IPv6 addresses are replaced with addresses starting from 2001:db8:ffff::
+- IPv6 unique local addresses (fc00::/7) are anonymized as well: their random global ID uniquely identifies the network.
+- IP addresses from internal IPv4 ranges and well-known addresses are not anonymized (e.g. 8.8.8.8, 100.64.0.0/10, addresses starting with 192.168., 172.16., 10., 169.254., fe80::).
+
+Strict level (--anonymize-level strict), in addition to the default level:
+- Private (RFC 1918), CGNAT (100.64.0.0/10), and link-local (169.254.0.0/16, fe80::/10) addresses are anonymized too.
+- Internal IPv4 addresses are replaced with addresses starting from 198.18.0.0 and internal IPv6 addresses with addresses starting from 2001:db8:1::, so internal addresses remain distinguishable from public ones.
+- Addresses are mapped in order of first appearance: subnet structure, allocation scheme, and gateway conventions are not preserved. Prefix lengths of networks are preserved.
+- Peer names in front of NetBird domains are replaced with numbered placeholders (e.g. peer-1.netbird.cloud), and subdomain labels of other domains with host-N placeholders.
+- WireGuard public keys are replaced with consistent placeholder keys.
 
-IP addresses from non public ranges and well known addresses are not anonymized (e.g. 8.8.8.8, 100.64.0.0/10, addresses starting with 192.168., 172.16., 10., etc.).
 Reoccuring IP addresses are replaced with the same anonymized address.
 
 Note: The anonymized IP addresses in the status file do not match those in the log and routes files. However, the anonymized IP addresses are consistent within the status file and across the routes and log files.
 
+MAC Addresses
+MAC addresses are replaced at every anonymization level with consistent placeholders counting up from 02:00:00:00:00:01. Broadcast, multicast, and all-zero addresses are kept. At the default level a preserved IPv6 link-local address may still embed a MAC address (EUI-64); the strict level anonymizes those addresses.
+
 Domains
 All domain names (except for the netbird domains) are replaced with randomly generated strings ending in ".domain". Anonymized domains are consistent across all files in the bundle.
 Reoccuring domain names are replaced with the same anonymized domain.
+At the strict level, the peer name labels in front of netbird domains are anonymized as well.
 
 Sync Response
 The network_map.json file contains the following anonymized information:
@@ -225,6 +238,13 @@ scutil_dns.txt (macOS only):
 - Shows DNS configuration for all network interfaces
 - Includes search domains, nameservers, and DNS resolver settings
 - All IP addresses and domain names are anonymized
+
+dns_windows.txt (Windows only):
+- Lists the NRPT rules of both policy stores, the local one and the group policy one, marking the rules the client created
+- Follows them with the policy table the resolver has loaded, which differs from the rules while a change has not been picked up yet
+- Includes the DNS client group policy, the global TCP/IP and Dnscache parameters, and the DNS values of every interface that has any
+- Ends with the resolver configuration in effect per adapter, from GetAdaptersAddresses
+- All IP addresses and domain names are anonymized
 `
 
 const (
@@ -232,6 +252,12 @@ const (
 	errorLogFile  = "netbird.err"
 	stdoutLogFile = "netbird.out"
 
+	// Rotated-log glob prefixes (base log name without extension) passed to
+	// addRotatedLogFiles. The daemon's own log and the GUI log live in the same
+	// dir, so the prefixes must be disjoint to keep their rotated siblings apart.
+	clientLogPrefix = "client"
+	uiLogPrefix     = "gui-client"
+
 	darwinErrorLogPath  = "/var/log/netbird.out.log"
 	darwinStdoutLogPath = "/var/log/netbird.err.log"
 )
@@ -241,6 +267,20 @@ type MetricsExporter interface {
 	Export(w io.Writer) error
 }
 
+// LogOpener opens a log file for inclusion in the bundle. It exists so that log
+// files whose path was supplied by an IPC caller can be opened under a check
+// the daemon defines, instead of being opened with the daemon's privileges
+// unconditionally.
+type LogOpener func(path string) (*os.File, error)
+
+func openLogFile(path string) (*os.File, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
 type BundleGenerator struct {
 	anonymizer *anonymize.Anonymizer
 
@@ -249,6 +289,8 @@ type BundleGenerator struct {
 	statusRecorder *peer.Status
 	syncResponse   *mgmProto.SyncResponse
 	logPath        string
+	uiLogPath      string
+	uiLogOpener    LogOpener
 	tempDir        string
 	statePath      string
 	cpuProfile     []byte
@@ -259,6 +301,7 @@ type BundleGenerator struct {
 	cliVersion     string
 
 	anonymize         bool
+	anonymizeLevel    anonymize.Level
 	includeSystemInfo bool
 	logFileCount      uint32
 
@@ -266,7 +309,10 @@ type BundleGenerator struct {
 }
 
 type BundleConfig struct {
-	Anonymize         bool
+	Anonymize bool
+	// AnonymizeLevel selects how much the anonymizer redacts.
+	// anonymize.LevelStrict implies Anonymize.
+	AnonymizeLevel    anonymize.Level
 	IncludeSystemInfo bool
 	LogFileCount      uint32
 }
@@ -276,14 +322,21 @@ type GeneratorDependencies struct {
 	StatusRecorder *peer.Status
 	SyncResponse   *mgmProto.SyncResponse
 	LogPath        string
-	TempDir        string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
-	StatePath      string // Path to the state file. If empty, the ServiceManager default path is used.
-	CPUProfile     []byte
-	CapturePath    string
-	RefreshStatus  func()
-	ClientMetrics  MetricsExporter
-	DaemonVersion  string
-	CliVersion     string
+	UILogPath      string // Absolute path to the desktop UI's gui-client.log, reported via RegisterUILog. Empty if no UI registered one.
+	// UILogOpener opens the UI log and its rotated siblings. The path comes from
+	// a local IPC caller, so the daemon must not open it with plain os.Open: the
+	// opener is where the caller's right to that file is enforced. Defaults to
+	// os.Open, which is only correct where the path is not caller-supplied
+	// (mobile).
+	UILogOpener   LogOpener
+	TempDir       string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
+	StatePath     string // Path to the state file. If empty, the ServiceManager default path is used.
+	CPUProfile    []byte
+	CapturePath   string
+	RefreshStatus func()
+	ClientMetrics MetricsExporter
+	DaemonVersion string
+	CliVersion    string
 }
 
 func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGenerator {
@@ -293,13 +346,23 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		logFileCount = 1
 	}
 
+	uiLogOpener := deps.UILogOpener
+	if uiLogOpener == nil {
+		uiLogOpener = openLogFile
+	}
+
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(cfg.AnonymizeLevel)
+
 	return &BundleGenerator{
-		anonymizer: anonymize.NewAnonymizer(anonymize.DefaultAddresses()),
+		anonymizer: anonymizer,
 
 		internalConfig: deps.InternalConfig,
 		statusRecorder: deps.StatusRecorder,
 		syncResponse:   deps.SyncResponse,
 		logPath:        deps.LogPath,
+		uiLogPath:      deps.UILogPath,
+		uiLogOpener:    uiLogOpener,
 		tempDir:        deps.TempDir,
 		statePath:      deps.StatePath,
 		cpuProfile:     deps.CPUProfile,
@@ -309,15 +372,45 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		daemonVersion:  deps.DaemonVersion,
 		cliVersion:     deps.CliVersion,
 
-		anonymize:         cfg.Anonymize,
+		anonymize:         cfg.Anonymize || cfg.AnonymizeLevel >= anonymize.LevelStrict,
+		anonymizeLevel:    cfg.AnonymizeLevel,
 		includeSystemInfo: cfg.IncludeSystemInfo,
 		logFileCount:      logFileCount,
 	}
 }
 
+// bundleFilePattern names the bundle zips Generate creates in tempDir; the
+// asterisk is filled in by os.CreateTemp.
+const bundleFilePattern = "netbird.debug.*.zip"
+
+const exportedBundlePrefix = "netbird.debug-file."
+
+const exportedBundleMaxAge = 24 * time.Hour
+
+// RemoveStaleBundles deletes bundle zips that an interrupted generation or
+// upload left behind in dir. Only files older than maxAge go, so a bundle that
+// another caller is still writing or uploading in the same directory survives.
+// Exported bundles are kept for exportedBundleMaxAge instead.
+func RemoveStaleBundles(dir string, maxAge time.Duration) {
+	removeStaleFiles(dir, bundleFilePattern, maxAge)
+	removeStaleFiles(dir, exportedBundlePrefix+"*.zip", exportedBundleMaxAge)
+}
+
+// ExportBundle renames a generated bundle out of the RemoveStaleBundles pattern
+// and returns the new path. The caller owns the file from then on; an export
+// abandoned for longer than exportedBundleMaxAge is removed by RemoveStaleBundles.
+func ExportBundle(path string) (string, error) {
+	base := strings.TrimPrefix(filepath.Base(path), strings.SplitN(bundleFilePattern, "*", 2)[0])
+	exported := filepath.Join(filepath.Dir(path), exportedBundlePrefix+base)
+	if err := os.Rename(path, exported); err != nil {
+		return "", fmt.Errorf("export debug bundle: %w", err)
+	}
+	return exported, nil
+}
+
 // Generate creates a debug bundle and returns the location.
 func (g *BundleGenerator) Generate() (resp string, err error) {
-	bundlePath, err := os.CreateTemp(g.tempDir, "netbird.debug.*.zip")
+	bundlePath, err := os.CreateTemp(g.tempDir, bundleFilePattern)
 	if err != nil {
 		return "", fmt.Errorf("create zip file: %w", err)
 	}
@@ -411,6 +504,10 @@ func (g *BundleGenerator) createArchive() error {
 		log.Errorf("failed to add logs to debug bundle: %v", err)
 	}
 
+	if err := g.addUILog(); err != nil {
+		log.Errorf("failed to add UI log to debug bundle: %v", err)
+	}
+
 	if err := g.addUpdateLogs(); err != nil {
 		log.Errorf("failed to add updater logs: %v", err)
 	}
@@ -445,7 +542,13 @@ func (g *BundleGenerator) addSystemInfo() {
 }
 
 func (g *BundleGenerator) addReadme() error {
-	readmeReader := strings.NewReader(readmeContent)
+	level := "none (anonymization disabled)"
+	if g.anonymize {
+		level = g.anonymizeLevel.String()
+	}
+	header := fmt.Sprintf("Netbird debug bundle\nAnonymization level applied to this bundle: %s\n", level)
+
+	readmeReader := strings.NewReader(header + readmeContent)
 	if err := g.addFileToZip(readmeReader, "README.txt"); err != nil {
 		return fmt.Errorf("add README file to zip: %w", err)
 	}
@@ -466,11 +569,11 @@ func (g *BundleGenerator) addStatus() error {
 
 		fullStatus := g.statusRecorder.GetFullStatus()
 		protoFullStatus := nbstatus.ToProtoFullStatus(fullStatus)
-		protoFullStatus.Events = g.statusRecorder.GetEventHistory()
 		overview := nbstatus.ConvertToStatusOutputOverview(protoFullStatus, nbstatus.ConvertOptions{
-			Anonymize:     g.anonymize,
-			ProfileName:   profName,
-			DaemonVersion: g.daemonVersion,
+			Anonymize:      g.anonymize,
+			AnonymizeLevel: g.anonymizeLevel,
+			ProfileName:    profName,
+			DaemonVersion:  g.daemonVersion,
 		})
 		overview.CliVersion = g.cliVersion
 		statusOutput := overview.FullDetailSummary()
@@ -544,7 +647,7 @@ const (
 	jsonKeyServiceEnv    = "service_env_vars"
 )
 
-var sensitiveEnvSubstrings = []string{"key", "token", "secret", "password", "credential"}
+var sensitiveEnvSubstrings = []string{"key", "token", "secret", "password", "credential", "pin", "pkcs11"}
 
 // addServiceParams reads the service.json file and adds a sanitized version to the bundle.
 // Non-NB_ env vars and vars with sensitive names are masked. Other NB_ values are anonymized.
@@ -623,7 +726,7 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	configContent.WriteString("NetBird Client Configuration:\n\n")
 
 	if key, err := wgtypes.ParseKey(g.internalConfig.PrivateKey); err == nil {
-		configContent.WriteString(fmt.Sprintf("PublicKey: %s\n", key.PublicKey().String()))
+		configContent.WriteString(fmt.Sprintf("PublicKey: %s\n", g.anonymizer.AnonymizeWGKey(key.PublicKey().String())))
 	}
 	configContent.WriteString(fmt.Sprintf("WgIface: %s\n", g.internalConfig.WgIface))
 	configContent.WriteString(fmt.Sprintf("WgPort: %d\n", g.internalConfig.WgPort))
@@ -637,6 +740,9 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	if g.internalConfig.ServerSSHAllowed != nil {
 		configContent.WriteString(fmt.Sprintf("ServerSSHAllowed: %v\n", *g.internalConfig.ServerSSHAllowed))
 	}
+	if g.internalConfig.RemoteJobsAllowed != nil {
+		configContent.WriteString(fmt.Sprintf("RemoteJobsAllowed: %v\n", *g.internalConfig.RemoteJobsAllowed))
+	}
 	if g.internalConfig.EnableSSHRoot != nil {
 		configContent.WriteString(fmt.Sprintf("EnableSSHRoot: %v\n", *g.internalConfig.EnableSSHRoot))
 	}
@@ -663,6 +769,9 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	configContent.WriteString(fmt.Sprintf("BlockLANAccess: %v\n", g.internalConfig.BlockLANAccess))
 	configContent.WriteString(fmt.Sprintf("BlockInbound: %v\n", g.internalConfig.BlockInbound))
 	configContent.WriteString(fmt.Sprintf("DisableIPv6: %v\n", g.internalConfig.DisableIPv6))
+	configContent.WriteString(fmt.Sprintf("LocalMetricsEnabled: %v\n", g.internalConfig.LocalMetricsEnabled))
+	configContent.WriteString(fmt.Sprintf("LocalMetricsAddress: %s\n", g.internalConfig.LocalMetricsAddress))
+	configContent.WriteString(fmt.Sprintf("SyncMessageVersion: %v\n", g.internalConfig.SyncMessageVersion))
 
 	if g.internalConfig.DisableNotifications != nil {
 		configContent.WriteString(fmt.Sprintf("DisableNotifications: %v\n", *g.internalConfig.DisableNotifications))
@@ -912,6 +1021,11 @@ func (g *BundleGenerator) addUpdateLogs() error {
 		}
 
 		baseName := filepath.Base(logFile)
+		data, err = g.anonymizeBytes(data)
+		if err != nil {
+			log.Warnf("skipping update log file %s: %v", baseName, err)
+			continue
+		}
 		if err := g.addFileToZip(bytes.NewReader(data), filepath.Join("update-logs", baseName)); err != nil {
 			return fmt.Errorf("add update log file %s to zip: %w", baseName, err)
 		}
@@ -939,6 +1053,13 @@ func (g *BundleGenerator) addCorruptedStateFiles() error {
 		}
 
 		fileName := filepath.Base(match)
+		// Corrupted state files usually fail structured JSON anonymization,
+		// so run them through the string anonymizer instead.
+		data, err = g.anonymizeBytes(data)
+		if err != nil {
+			log.Warnf("skipping corrupted state file %s: %v", fileName, err)
+			continue
+		}
 		if err := g.addFileToZip(bytes.NewReader(data), "corrupted_states/"+fileName); err != nil {
 			log.Warnf("Failed to add corrupted state file %s to zip: %v", fileName, err)
 			continue
@@ -950,6 +1071,27 @@ func (g *BundleGenerator) addCorruptedStateFiles() error {
 	return nil
 }
 
+// anonymizeBytes runs raw file content through the string anonymizer line by
+// line when anonymization is enabled. It errors instead of returning partial
+// content, so a caller never adds an unanonymized fallback to the bundle.
+func (g *BundleGenerator) anonymizeBytes(data []byte) ([]byte, error) {
+	if !g.anonymize {
+		return data, nil
+	}
+
+	var buf bytes.Buffer
+	scanner := bufio.NewScanner(bytes.NewReader(data))
+	scanner.Buffer(make([]byte, 1024*1024), 1024*1024)
+	for scanner.Scan() {
+		buf.WriteString(g.anonymizer.AnonymizeString(scanner.Text()))
+		buf.WriteByte('\n')
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("anonymize content: %w", err)
+	}
+	return buf.Bytes(), nil
+}
+
 func (g *BundleGenerator) addMetrics() error {
 	if g.clientMetrics == nil {
 		log.Debugf("skipping metrics in debug bundle: no metrics collector")
@@ -982,11 +1124,11 @@ func (g *BundleGenerator) addLogfile() error {
 
 	logDir := filepath.Dir(g.logPath)
 
-	if err := g.addSingleLogfile(g.logPath, clientLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, g.logPath, clientLogFile); err != nil {
 		return fmt.Errorf("add client log file to zip: %w", err)
 	}
 
-	g.addRotatedLogFiles(logDir)
+	g.addRotatedLogFiles(openLogFile, logDir, clientLogPrefix)
 
 	stdErrLogPath := filepath.Join(logDir, errorLogFile)
 	stdoutLogPath := filepath.Join(logDir, stdoutLogFile)
@@ -995,20 +1137,39 @@ func (g *BundleGenerator) addLogfile() error {
 		stdoutLogPath = darwinStdoutLogPath
 	}
 
-	if err := g.addSingleLogfile(stdErrLogPath, errorLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdErrLogPath, errorLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", errorLogFile, err)
 	}
 
-	if err := g.addSingleLogfile(stdoutLogPath, stdoutLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdoutLogPath, stdoutLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", stdoutLogFile, err)
 	}
 
 	return nil
 }
 
+// addUILog adds the desktop UI's gui-client.log (and its rotated siblings) to
+// the bundle. The path is reported by the UI via RegisterUILog; empty when no
+// UI registered one (e.g. headless / server). Missing file is non-fatal — the
+// UI only writes it while the daemon is in debug, so it's often absent.
+func (g *BundleGenerator) addUILog() error {
+	if g.uiLogPath == "" {
+		log.Debugf("no UI log path registered, skipping in debug bundle")
+		return nil
+	}
+
+	if err := g.addSingleLogfile(g.uiLogOpener, g.uiLogPath, configs.UILogFile); err != nil {
+		return fmt.Errorf("add UI log file to zip: %w", err)
+	}
+
+	g.addRotatedLogFiles(g.uiLogOpener, filepath.Dir(g.uiLogPath), uiLogPrefix)
+
+	return nil
+}
+
 // addSingleLogfile adds a single log file to the archive
-func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
-	logFile, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogfile(open LogOpener, logPath, targetName string) error {
+	logFile, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open log file %s: %w", targetName, err)
 	}
@@ -1033,8 +1194,8 @@ func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
 }
 
 // addSingleLogFileGz adds a single gzipped log file to the archive
-func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
-	f, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogFileGz(open LogOpener, logPath, targetName string) error {
+	f, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open gz log file %s: %w", targetName, err)
 	}
@@ -1078,14 +1239,16 @@ func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
 	return nil
 }
 
-// addRotatedLogFiles adds rotated log files to the bundle based on logFileCount
-func (g *BundleGenerator) addRotatedLogFiles(logDir string) {
+// addRotatedLogFiles adds rotated log files to the bundle based on logFileCount.
+// prefix is the base log name without extension (e.g. "client", "gui-client");
+// the glob matches both files rotated by us and by logrotate on linux.
+func (g *BundleGenerator) addRotatedLogFiles(open LogOpener, logDir, prefix string) {
 	if g.logFileCount == 0 {
 		return
 	}
 
-	// This regex will match both logs rotated by us and logrotate on linux
-	pattern := filepath.Join(logDir, "client*.log.*")
+	// This pattern matches both logs rotated by us and logrotate on linux
+	pattern := filepath.Join(logDir, prefix+"*.log.*")
 	files, err := filepath.Glob(pattern)
 	if err != nil {
 		log.Warnf("failed to glob rotated logs: %v", err)
@@ -1119,9 +1282,9 @@ func (g *BundleGenerator) addRotatedLogFiles(logDir string) {
 	for i := 0; i < maxFiles; i++ {
 		name := filepath.Base(files[i])
 		if strings.HasSuffix(name, ".gz") {
-			err = g.addSingleLogFileGz(files[i], name)
+			err = g.addSingleLogFileGz(open, files[i], name)
 		} else {
-			err = g.addSingleLogfile(files[i], name)
+			err = g.addSingleLogfile(open, files[i], name)
 		}
 		if err != nil {
 			log.Warnf("failed to add rotated log %s: %v", name, err)
@@ -1401,6 +1564,7 @@ func anonymizeRemotePeer(peer *mgmProto.RemotePeerConfig, anonymizer *anonymize.
 	}
 
 	peer.Fqdn = anonymizer.AnonymizeDomain(peer.Fqdn)
+	peer.WgPubKey = anonymizer.AnonymizeWGKey(peer.WgPubKey)
 
 	anonymizeSSHConfig(peer.SshConfig)
 }
@@ -1590,3 +1754,26 @@ func anonymizeSlice(v []any, anonymizer *anonymize.Anonymizer) []any {
 	}
 	return v
 }
+
+func removeStaleFiles(dir, pattern string, maxAge time.Duration) {
+	matches, err := filepath.Glob(filepath.Join(dir, pattern))
+	if err != nil {
+		log.Debugf("glob stale debug bundles in %s: %v", dir, err)
+		return
+	}
+
+	cutoff := time.Now().Add(-maxAge)
+	for _, path := range matches {
+		info, err := os.Stat(path)
+		if err != nil || info.ModTime().After(cutoff) {
+			continue
+		}
+		if err := os.Remove(path); err != nil {
+			if !errors.Is(err, fs.ErrNotExist) {
+				log.Warnf("remove stale debug bundle %s: %v", path, err)
+			}
+			continue
+		}
+		log.Infof("removed stale debug bundle %s", path)
+	}
+}

client/internal/debug/debug_ios.go

@@ -27,7 +27,7 @@ func (g *BundleGenerator) addPlatformLog() error {
 	}
 
 	swiftLogPath := filepath.Join(filepath.Dir(g.logPath), swiftLogFile)
-	if err := g.addSingleLogfile(swiftLogPath, swiftLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, swiftLogPath, swiftLogFile); err != nil {
 		// The Swift log is best-effort: the app may not have written it yet.
 		log.Warnf("failed to add %s to debug bundle: %v", swiftLogFile, err)
 	}

client/internal/debug/debug_linux.go

@@ -844,6 +844,10 @@ func collectSysctls() string {
 		[]string{"net.ipv4.conf.all.src_valid_mark", "net.ipv4.conf.default.src_valid_mark"},
 		listInterfaceSysctls("ipv4", "src_valid_mark")...,
 	))
+	writeSysctlGroup(&builder, "accept_ra", append(
+		[]string{"net.ipv6.conf.all.accept_ra", "net.ipv6.conf.default.accept_ra"},
+		listInterfaceSysctls("ipv6", "accept_ra")...,
+	))
 	writeSysctlGroup(&builder, "conntrack", []string{
 		"net.netfilter.nf_conntrack_acct",
 		"net.netfilter.nf_conntrack_tcp_loose",

client/internal/debug/debug_logfiles_test.go

@@ -40,6 +40,25 @@ func TestAddRotatedLogFiles_PicksUpAllVariants(t *testing.T) {
 	require.NotContains(t, names, "other.log", "unrelated files should not be in bundle")
 }
 
+// TestAddRotatedLogFiles_GUIPrefix asserts the prefix parameter scopes the glob
+// to the GUI log: gui-client.log.* rotated siblings are picked up and the
+// daemon's own client.log.* are not (and vice versa, covered above). This is
+// the load-bearing check for the gui-client.log bundle collection — the old
+// "client*.log.*" glob would have missed gui-client rotations.
+func TestAddRotatedLogFiles_GUIPrefix(t *testing.T) {
+	dir := t.TempDir()
+
+	writeFile(t, filepath.Join(dir, "gui-client.log.1"), "gui rotated\n")
+	writeGzFile(t, filepath.Join(dir, "gui-client.log.2.gz"), "gui rotated gz\n")
+	writeFile(t, filepath.Join(dir, "client.log.1"), "daemon rotated\n")
+
+	names := runAddRotatedLogFilesPrefix(t, dir, "gui-client", 10)
+
+	require.Contains(t, names, "gui-client.log.1", "gui-client rotated file should be in bundle")
+	require.Contains(t, names, "gui-client.log.2.gz", "gui-client gz rotated file should be in bundle")
+	require.NotContains(t, names, "client.log.1", "daemon rotated file must not match the gui-client prefix")
+}
+
 // TestAddRotatedLogFiles_RespectsLogFileCount asserts that only the newest
 // logFileCount rotated files are bundled, ordered by mtime.
 func TestAddRotatedLogFiles_RespectsLogFileCount(t *testing.T) {
@@ -67,6 +86,10 @@ func TestAddRotatedLogFiles_RespectsLogFileCount(t *testing.T) {
 // runAddRotatedLogFiles calls addRotatedLogFiles against a fresh in-memory
 // zip writer and returns the set of entry names that ended up in the archive.
 func runAddRotatedLogFiles(t *testing.T, dir string, logFileCount uint32) map[string]struct{} {
+	return runAddRotatedLogFilesPrefix(t, dir, "client", logFileCount)
+}
+
+func runAddRotatedLogFilesPrefix(t *testing.T, dir, prefix string, logFileCount uint32) map[string]struct{} {
 	t.Helper()
 
 	var buf bytes.Buffer
@@ -74,7 +97,7 @@ func runAddRotatedLogFiles(t *testing.T, dir string, logFileCount uint32) map[st
 		archive:      zip.NewWriter(&buf),
 		logFileCount: logFileCount,
 	}
-	g.addRotatedLogFiles(dir)
+	g.addRotatedLogFiles(openLogFile, dir, prefix)
 	require.NoError(t, g.archive.Close())
 
 	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))

client/internal/debug/debug_nonunix.go

@@ -1,4 +1,4 @@
-//go:build !unix
+//go:build !unix && !windows
 
 package debug
 

client/internal/debug/debug_test.go

@@ -4,6 +4,7 @@ import (
 	"archive/zip"
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"net"
 	"net/netip"
 	"net/url"
@@ -457,6 +458,9 @@ func TestIsSensitiveEnvVar(t *testing.T) {
 		{"NB_CLIENT_SECRET", true},
 		{"NB_PASSWORD", true},
 		{"NB_CREDENTIAL", true},
+		// The token PIN, and the token URI, which may carry the PIN as pin-value.
+		{"NB_TPM_PIN", true},
+		{"NB_CERT_PKCS11_URI", true},
 		{"NB_LOG_LEVEL", false},
 		{"NB_MANAGEMENT_URL", false},
 		{"NB_HOSTNAME", false},
@@ -839,12 +843,16 @@ COMMIT`
 // the excluded set with a justification.
 func TestAddConfig_AllFieldsCovered(t *testing.T) {
 	excluded := map[string]string{
-		"PrivateKey":        "sensitive: WireGuard private key",
-		"PreSharedKey":      "sensitive: WireGuard pre-shared key",
-		"SSHKey":            "sensitive: SSH private key",
-		"ClientCertKeyPair": "non-config: parsed cert pair, not serialized",
-		"Name":              "non-config: profile name is not needed for debug purposes",
-		"policy":            "non-config: in-memory MDM policy snapshot, surfaced via Config.Policy() / GetConfigResponse.MDMManagedFields",
+		"PrivateKey":           "sensitive: WireGuard private key",
+		"PreSharedKey":         "sensitive: WireGuard pre-shared key",
+		"SSHKey":               "sensitive: SSH private key",
+		"ClientCertKeyPair":    "non-config: parsed cert pair, not serialized",
+		"Name":                 "non-config: profile name is not needed for debug purposes",
+		"policy":               "non-config: in-memory MDM policy snapshot, surfaced via Config.Policy() / GetConfigResponse.MDMManagedFields",
+		"probing":              "non-config: marks a throwaway copy built to be diffed against; never set on a config anyone runs with",
+		"DebugBundleUploadURL": "sensitive: MDM-provided upload URL may carry credentials or query tokens; kept out of the shared bundle",
+		"CertPKCS11URI":        "deprecated and ignored; sensitive: the URI may carry the token PIN as pin-value",
+		"CertStoreDir":         "deprecated and ignored: the directory comes from NB_CERT_STORE_DIR",
 	}
 
 	mURL, _ := url.Parse("https://api.example.com:443")
@@ -864,6 +872,7 @@ func TestAddConfig_AllFieldsCovered(t *testing.T) {
 		RosenpassEnabled:              true,
 		RosenpassPermissive:           true,
 		ServerSSHAllowed:              &bTrue,
+		RemoteJobsAllowed:             &bTrue,
 		EnableSSHRoot:                 &bTrue,
 		EnableSSHSFTP:                 &bTrue,
 		EnableSSHLocalPortForwarding:  &bTrue,
@@ -886,7 +895,11 @@ func TestAddConfig_AllFieldsCovered(t *testing.T) {
 		ClientCertPath:                "/tmp/cert",
 		ClientCertKeyPath:             "/tmp/key",
 		LazyConnection:                "on",
+		DebugBundleUploadURL:          "https://upload.example.test/bundle?token=secret",
+		CertPKCS11URI:                 "pkcs11:token=netbird?pin-value=pin-secret",
 		MTU:                           1280,
+		DisableIPv6:                   true,
+		SyncMessageVersion:            func(v int) *int { return &v }(1),
 	}
 
 	for _, anonymize := range []bool{false, true} {
@@ -901,6 +914,17 @@ func TestAddConfig_AllFieldsCovered(t *testing.T) {
 			g.addCommonConfigFields(&sb)
 			rendered := sb.String() + renderAddConfigSpecific(g)
 
+			// DebugBundleUploadURL is an MDM-provided value that can carry
+			// credentials or signed query tokens. It is deliberately excluded
+			// above; assert it never reaches the rendered bundle — neither the
+			// field name nor the token — in either anonymize mode.
+			assert.NotContains(t, rendered, "DebugBundleUploadURL:", "MDM upload URL field must not be serialized into the debug bundle")
+			assert.NotContains(t, rendered, "token=secret", "MDM upload URL value must not leak into the debug bundle")
+
+			// A leftover CertPKCS11URI may carry the token PIN as pin-value.
+			assert.NotContains(t, rendered, "CertPKCS11URI", "PKCS#11 URI field must not be serialized into the debug bundle")
+			assert.NotContains(t, rendered, "pin-secret", "PKCS#11 PIN must not leak into the debug bundle")
+
 			val := reflect.ValueOf(cfg).Elem()
 			typ := val.Type()
 			var missing []string
@@ -957,3 +981,52 @@ func renderAddConfigSpecific(g *BundleGenerator) string {
 func newAnonymizerForTest() *anonymize.Anonymizer {
 	return anonymize.NewAnonymizer(anonymize.DefaultAddresses())
 }
+
+func TestRemoveStaleBundles(t *testing.T) {
+	dir := t.TempDir()
+	stale := filepath.Join(dir, "netbird.debug.111.zip")
+	fresh := filepath.Join(dir, "netbird.debug.222.zip")
+	other := filepath.Join(dir, "netbird.debug.333.txt")
+	owned := filepath.Join(dir, "netbird.debug.444.zip")
+	abandoned := filepath.Join(dir, "netbird.debug.555.zip")
+	for _, p := range []string{stale, fresh, other, owned, abandoned} {
+		require.NoError(t, os.WriteFile(p, []byte("x"), 0o600))
+	}
+	exported, err := ExportBundle(owned)
+	require.NoError(t, err)
+	exportedAbandoned, err := ExportBundle(abandoned)
+	require.NoError(t, err)
+	old := time.Now().Add(-2 * time.Hour)
+	for _, p := range []string{stale, other, exported} {
+		require.NoError(t, os.Chtimes(p, old, old))
+	}
+	ancient := time.Now().Add(-exportedBundleMaxAge - time.Hour)
+	require.NoError(t, os.Chtimes(exportedAbandoned, ancient, ancient))
+
+	RemoveStaleBundles(dir, time.Hour)
+
+	assert.NoFileExists(t, stale, "bundle older than maxAge should be removed")
+	assert.FileExists(t, fresh, "bundle younger than maxAge must survive, it may still be uploading")
+	assert.FileExists(t, other, "files outside the bundle pattern must not be touched")
+	assert.NoFileExists(t, owned)
+	assert.FileExists(t, exported, "exported bundle is caller-owned and must survive maxAge")
+	assert.NoFileExists(t, exportedAbandoned, "exported bundle older than exportedBundleMaxAge is abandoned")
+}
+
+func TestBundleIncludesNetworkMap(t *testing.T) {
+	for _, anonymize := range []bool{false, true} {
+		t.Run(fmt.Sprintf("anonymize=%t", anonymize), func(t *testing.T) {
+			g := NewBundleGenerator(GeneratorDependencies{
+				SyncResponse: &mgmProto.SyncResponse{NetworkMap: &mgmProto.NetworkMap{Serial: 1}},
+			}, BundleConfig{Anonymize: anonymize})
+
+			require.Contains(t, bundleEntries(t, g), "network_map.json")
+		})
+	}
+}
+
+func TestBundleOmitsNetworkMapWithoutSyncResponse(t *testing.T) {
+	g := NewBundleGenerator(GeneratorDependencies{}, BundleConfig{})
+
+	require.NotContains(t, bundleEntries(t, g), "network_map.json")
+}

client/internal/debug/debug_windows.go

@@ -0,0 +1,443 @@
+//go:build windows
+
+package debug
+
+import (
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net/netip"
+	"strings"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/registry"
+
+	nbdns "github.com/netbirdio/netbird/client/internal/dns"
+)
+
+const dnsInfoFileName = "dns_windows.txt"
+
+const (
+	gpoDNSClientRoot = `SOFTWARE\Policies\Microsoft\Windows NT\DNSClient`
+	tcpipParamsPath  = `SYSTEM\CurrentControlSet\Services\Tcpip\Parameters`
+	dnscacheParams   = `SYSTEM\CurrentControlSet\Services\Dnscache\Parameters`
+)
+
+// interfaceDNSValues are the per-interface values that decide how a name is
+// resolved and registered. Everything the DNS host manager writes is in here,
+// so a bundle shows both what we set and what it replaced.
+var interfaceDNSValues = []string{
+	"NameServer",
+	"DhcpNameServer",
+	"Domain",
+	"DhcpDomain",
+	"SearchList",
+	"RegistrationEnabled",
+	"DisableDynamicUpdate",
+	"MaxNumberOfAddressesToRegister",
+	"EnableDHCP",
+}
+
+// addDNSInfo collects and adds DNS configuration information to the archive
+func (g *BundleGenerator) addDNSInfo() error {
+	if err := g.addFileToZip(strings.NewReader(g.collectDNSInfo()), dnsInfoFileName); err != nil {
+		return fmt.Errorf("add DNS info to zip: %w", err)
+	}
+
+	return nil
+}
+
+// collectDNSInfo renders the report. Everything below it reaches the platform
+// through COM and through lazily resolved procedures, which panic when a
+// procedure is missing rather than returning an error, and a debug bundle is not
+// allowed to take the daemon down. The panic is contained here, and whatever was
+// collected before it is kept and reported with it.
+func (g *BundleGenerator) collectDNSInfo() (content string) {
+	var sb strings.Builder
+
+	defer func() {
+		if r := recover(); r != nil {
+			log.Errorf("collecting Windows DNS configuration panicked: %v", r)
+			fmt.Fprintf(&sb, "\nerror: collection stopped: %v\n", r)
+		}
+		content = sb.String()
+	}()
+
+	sb.WriteString("Windows DNS configuration\n")
+	sb.WriteString("=========================\n")
+
+	adapters, adaptersErr := adapterAddresses()
+
+	g.writeNRPTRules(&sb, "NRPT rules, local policy store", nbdns.DNSPolicyConfigRoot)
+	g.writeNRPTRules(&sb, "NRPT rules, group policy store", nbdns.GPODNSPolicyConfigRoot)
+	g.writeEffectiveNRPTPolicies(&sb)
+	g.writeRegistryKey(&sb, "DNS client group policy", gpoDNSClientRoot)
+	g.writeRegistryKey(&sb, "Global TCP/IP parameters", tcpipParamsPath)
+	g.writeRegistryKey(&sb, "Dnscache parameters", dnscacheParams)
+	g.writeInterfaceDNS(&sb, "Per-interface DNS, IPv4", nbdns.InterfaceConfigPath, adapterNames(adapters))
+	g.writeInterfaceDNS(&sb, "Per-interface DNS, IPv6", nbdns.InterfaceConfigPathV6, adapterNames(adapters))
+	g.writeAdapterDNS(&sb, adapters, adaptersErr)
+
+	return sb.String()
+}
+
+// writeNRPTRules lists every rule in a policy store, ours and any other
+// product's, since a foreign rule for the same namespace decides resolution
+// just as ours does. Rules the client wrote are marked.
+func (g *BundleGenerator) writeNRPTRules(sb *strings.Builder, title, root string) {
+	writeSection(sb, title, root)
+
+	names, err := subKeyNames(root)
+	if err != nil {
+		fmt.Fprintf(sb, "error: %v\n", err)
+		return
+	}
+
+	if len(names) == 0 {
+		sb.WriteString("no rules\n")
+		return
+	}
+
+	for _, name := range names {
+		owner := ""
+		if strings.HasPrefix(strings.ToLower(name), strings.ToLower(nbdns.NRPTKeyPrefix)) {
+			owner = "  (netbird)"
+		}
+		fmt.Fprintf(sb, "%s%s\n", name, owner)
+		g.writeValues(sb, root+`\`+name, nil, "  ")
+	}
+}
+
+// writeEffectiveNRPTPolicies reports the table the resolver answers from, which
+// the registry cannot show: a rule is written before it is loaded, and it keeps
+// being enforced after its key is gone until the resolver reloads its policy.
+func (g *BundleGenerator) writeEffectiveNRPTPolicies(sb *strings.Builder) {
+	writeSection(sb, "NRPT policy table in effect", nrptPolicyClass+"."+nrptPolicyMethod+" in "+nrptPolicyNamespace)
+
+	entries, err := effectiveNRPTPolicies()
+	if err != nil {
+		fmt.Fprintf(sb, "error: %v\n", err)
+		return
+	}
+
+	if len(entries) == 0 {
+		sb.WriteString("no policies\n")
+		return
+	}
+
+	for _, entry := range entries {
+		fmt.Fprintf(sb, "%s\n", g.anonymizeValue("Namespace", entry.namespace))
+		for _, value := range entry.values {
+			fmt.Fprintf(sb, "  %s: %s\n", value.name, g.anonymizeValue(value.name, value.value))
+		}
+	}
+}
+
+// writeInterfaceDNS reports the DNS values of every interface that has any, so
+// the netbird interface can be compared against the physical ones. The registry
+// keys the values by GUID, so each is named from the adapter list; a GUID with
+// no adapter is a leftover key of an interface that no longer exists.
+func (g *BundleGenerator) writeInterfaceDNS(sb *strings.Builder, title, root string, names map[string]string) {
+	writeSection(sb, title, root)
+
+	guids, err := subKeyNames(root)
+	if err != nil {
+		fmt.Fprintf(sb, "error: %v\n", err)
+		return
+	}
+
+	var reported int
+	for _, guid := range guids {
+		var iface strings.Builder
+		g.writeValues(&iface, root+`\`+guid, interfaceDNSValues, "  ")
+		if iface.Len() == 0 {
+			continue
+		}
+
+		name, ok := names[strings.ToLower(guid)]
+		if !ok {
+			name = "no adapter with this GUID"
+		}
+
+		reported++
+		fmt.Fprintf(sb, "%s (%s)\n%s", guid, name, iface.String())
+	}
+
+	if reported == 0 {
+		sb.WriteString("no interface holds DNS values\n")
+	}
+}
+
+// writeRegistryKey reports the values of a single key, without its subkeys.
+func (g *BundleGenerator) writeRegistryKey(sb *strings.Builder, title, path string) {
+	writeSection(sb, title, path)
+
+	var values strings.Builder
+	g.writeValues(&values, path, nil, "")
+	if values.Len() == 0 {
+		sb.WriteString("no values\n")
+		return
+	}
+
+	sb.WriteString(values.String())
+}
+
+// writeValues renders the values of a key. A nil names list reports every
+// value, otherwise only those named and present.
+func (g *BundleGenerator) writeValues(sb *strings.Builder, path string, names []string, indent string) {
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, path, registry.QUERY_VALUE)
+	switch {
+	case errors.Is(err, registry.ErrNotExist), errors.Is(err, windows.ERROR_PATH_NOT_FOUND):
+		// an absent key is the normal state for the GPO store and for
+		// interfaces without DNS settings
+		log.Debugf("HKEY_LOCAL_MACHINE\\%s does not exist", path)
+		return
+	case err != nil:
+		fmt.Fprintf(sb, "%serror: open HKEY_LOCAL_MACHINE\\%s: %v\n", indent, path, err)
+		return
+	}
+	defer closeKey(k)
+
+	if names == nil {
+		names, err = k.ReadValueNames(-1)
+		if err != nil {
+			fmt.Fprintf(sb, "%serror: read value names: %v\n", indent, err)
+			return
+		}
+	}
+
+	for _, name := range names {
+		value, err := readRegistryValue(k, name)
+		switch {
+		case errors.Is(err, registry.ErrNotExist):
+			// the caller asks for a fixed set of values, most of which a
+			// given interface does not carry
+			continue
+		case err != nil:
+			// report rather than omit: a value that is there but cannot be
+			// read reads as unset otherwise
+			fmt.Fprintf(sb, "%s%s: error: %v\n", indent, name, err)
+			continue
+		}
+
+		fmt.Fprintf(sb, "%s%s: %s\n", indent, name, g.anonymizeValue(name, value))
+	}
+}
+
+// anonymizeValue redacts a registry value according to what its name says it
+// holds. Domains and addresses are handled per entry rather than by the string
+// pass: the pass only replaces domains something else in the bundle already
+// seeded, and its address regex would eat the digit labels of a reverse zone.
+func (g *BundleGenerator) anonymizeValue(name, value string) string {
+	if !g.anonymize || value == "" {
+		return value
+	}
+
+	switch {
+	case holdsDomains(name):
+		return joinValueEntries(splitValueEntries(value), g.anonymizeDomain)
+	case holdsAddresses(name):
+		return joinValueEntries(splitValueEntries(value), g.anonymizer.AnonymizeIPString)
+	default:
+		return g.anonymizer.AnonymizeString(value)
+	}
+}
+
+// holdsDomains reports whether a value name holds domains: the domain list of
+// an NRPT rule (Name) or of the policy table (Namespace), a search list, the
+// DNS suffix values of the TCP/IP and policy keys, which all end in "Domain"
+// (Domain, DhcpDomain, NV Domain, ICSDomain), and a proxy host name.
+func holdsDomains(name string) bool {
+	lower := strings.ToLower(name)
+	return lower == "name" || lower == "namespace" || lower == "searchlist" ||
+		strings.HasSuffix(lower, "domain") || strings.HasSuffix(lower, "proxyname")
+}
+
+// holdsAddresses reports whether a value name holds DNS server addresses
+// (NameServer, DhcpNameServer, GenericDNSServers, NameServers).
+func holdsAddresses(name string) bool {
+	lower := strings.ToLower(name)
+	return strings.Contains(lower, "nameserver") || strings.Contains(lower, "dnsserver")
+}
+
+// adapterNames maps adapter GUIDs, as the registry keys the interfaces, to the
+// names an operator sees.
+func adapterNames(adapters []*windows.IpAdapterAddresses) map[string]string {
+	names := make(map[string]string, len(adapters))
+	for _, adapter := range adapters {
+		guid := windows.BytePtrToString(adapter.AdapterName)
+		names[strings.ToLower(guid)] = windows.UTF16PtrToString(adapter.FriendlyName)
+	}
+	return names
+}
+
+// writeAdapterDNS reports the resolver configuration in effect per adapter,
+// which is what the resolver uses for a name no NRPT rule matches.
+func (g *BundleGenerator) writeAdapterDNS(sb *strings.Builder, adapters []*windows.IpAdapterAddresses, err error) {
+	writeSection(sb, "Adapter DNS configuration", "GetAdaptersAddresses")
+
+	if err != nil {
+		fmt.Fprintf(sb, "error: %v\n", err)
+		return
+	}
+
+	for _, adapter := range adapters {
+		name := windows.UTF16PtrToString(adapter.FriendlyName)
+		suffix := g.anonymizeDomain(windows.UTF16PtrToString(adapter.DnsSuffix))
+
+		fmt.Fprintf(sb, "%s (index %d, oper status %d)\n", name, adapter.IfIndex, adapter.OperStatus)
+		fmt.Fprintf(sb, "  DNS suffix: %s\n", suffix)
+
+		var servers []string
+		for server := adapter.FirstDnsServerAddress; server != nil; server = server.Next {
+			addr, ok := netip.AddrFromSlice(server.Address.IP())
+			if !ok {
+				continue
+			}
+
+			addr = addr.Unmap()
+			if g.anonymize {
+				addr = g.anonymizer.AnonymizeIP(addr)
+			}
+			servers = append(servers, addr.String())
+		}
+
+		fmt.Fprintf(sb, "  DNS servers: %s\n", strings.Join(servers, ", "))
+	}
+}
+
+// anonymizeDomain anonymizes a single domain, keeping the leading dot an NRPT
+// match domain carries.
+func (g *BundleGenerator) anonymizeDomain(entry string) string {
+	if !g.anonymize {
+		return entry
+	}
+
+	domain, dot := strings.CutPrefix(entry, ".")
+	if domain == "" {
+		return entry
+	}
+
+	anonymized := g.anonymizer.AnonymizeDomain(domain)
+	if dot {
+		anonymized = "." + anonymized
+	}
+	return anonymized
+}
+
+// splitValueEntries splits a registry value that holds a list. The separator
+// differs per value: a REG_MULTI_SZ arrives joined with ", ", a SearchList is
+// comma separated and a NameServer may use commas or spaces.
+func splitValueEntries(value string) []string {
+	return strings.FieldsFunc(value, func(r rune) bool {
+		return r == ',' || r == ';' || r == ' ' || r == '\t'
+	})
+}
+
+func joinValueEntries(entries []string, anonymize func(string) string) string {
+	for i, entry := range entries {
+		entries[i] = anonymize(entry)
+	}
+	return strings.Join(entries, ", ")
+}
+
+func writeSection(sb *strings.Builder, title, source string) {
+	fmt.Fprintf(sb, "\n%s\n%s\n%s\n", title, strings.Repeat("-", len(title)), source)
+}
+
+func subKeyNames(root string) ([]string, error) {
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, root, registry.ENUMERATE_SUB_KEYS)
+	if err != nil {
+		return nil, fmt.Errorf("open HKEY_LOCAL_MACHINE\\%s: %w", root, err)
+	}
+	defer closeKey(k)
+
+	names, err := k.ReadSubKeyNames(-1)
+	if err != nil {
+		return nil, fmt.Errorf("read subkey names: %w", err)
+	}
+
+	return names, nil
+}
+
+// readRegistryValue renders a value as text regardless of its type, so an
+// unexpected type in a policy key still shows up instead of being dropped.
+func readRegistryValue(k registry.Key, name string) (string, error) {
+	_, valueType, err := k.GetValue(name, nil)
+	if err != nil {
+		return "", fmt.Errorf("get value %s: %w", name, err)
+	}
+
+	switch valueType {
+	case registry.SZ, registry.EXPAND_SZ:
+		value, _, err := k.GetStringValue(name)
+		if err != nil {
+			return "", fmt.Errorf("get string value %s: %w", name, err)
+		}
+		return value, nil
+	case registry.MULTI_SZ:
+		values, _, err := k.GetStringsValue(name)
+		if err != nil {
+			return "", fmt.Errorf("get strings value %s: %w", name, err)
+		}
+		return strings.Join(values, ", "), nil
+	case registry.DWORD, registry.QWORD:
+		value, _, err := k.GetIntegerValue(name)
+		if err != nil {
+			return "", fmt.Errorf("get integer value %s: %w", name, err)
+		}
+		return fmt.Sprintf("%d (0x%x)", value, value), nil
+	case registry.BINARY:
+		value, _, err := k.GetBinaryValue(name)
+		if err != nil {
+			return "", fmt.Errorf("get binary value %s: %w", name, err)
+		}
+		return hex.EncodeToString(value), nil
+	default:
+		return fmt.Sprintf("<unhandled registry type %d>", valueType), nil
+	}
+}
+
+// adapterAddresses returns the adapter list including DNS servers. The call
+// reports the size it needs, so grow the buffer and retry until it fits.
+func adapterAddresses() (adapters []*windows.IpAdapterAddresses, err error) {
+	// GetAdaptersAddresses is resolved on first use and panics when it is
+	// missing, so this reports it as an error and leaves the rest of the
+	// report intact.
+	defer func() {
+		if r := recover(); r != nil {
+			adapters, err = nil, fmt.Errorf("GetAdaptersAddresses: %v", r)
+		}
+	}()
+
+	const flags = windows.GAA_FLAG_SKIP_ANYCAST | windows.GAA_FLAG_SKIP_MULTICAST
+
+	size := uint32(15000)
+	for range 3 {
+		buf := make([]byte, size)
+		first := (*windows.IpAdapterAddresses)(unsafe.Pointer(&buf[0]))
+
+		err := windows.GetAdaptersAddresses(windows.AF_UNSPEC, flags, 0, first, &size)
+		if errors.Is(err, windows.ERROR_BUFFER_OVERFLOW) {
+			continue
+		}
+		if err != nil {
+			return nil, fmt.Errorf("GetAdaptersAddresses: %w", err)
+		}
+
+		for adapter := first; adapter != nil; adapter = adapter.Next {
+			adapters = append(adapters, adapter)
+		}
+		return adapters, nil
+	}
+
+	return nil, fmt.Errorf("GetAdaptersAddresses: buffer kept growing")
+}
+
+func closeKey(k registry.Key) {
+	if err := k.Close(); err != nil {
+		log.Debugf("close registry key: %v", err)
+	}
+}

client/internal/debug/debug_windows_test.go

@@ -0,0 +1,146 @@
+//go:build windows
+
+package debug
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/anonymize"
+)
+
+func newDNSValueGenerator(level anonymize.Level) *BundleGenerator {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(level)
+
+	return &BundleGenerator{
+		anonymize:      true,
+		anonymizeLevel: level,
+		anonymizer:     anonymizer,
+	}
+}
+
+// TestAnonymizeValueByName covers the value kinds of the DNS registry keys. The
+// names decide the treatment, because the string pass alone replaces only
+// domains another part of the bundle already seeded.
+func TestAnonymizeValueByName(t *testing.T) {
+	tests := []struct {
+		name      string
+		valueName string
+		value     string
+		assert    func(t *testing.T, got string)
+	}{
+		{
+			name:      "NRPT match domains keep the leading dot",
+			valueName: "Name",
+			value:     ".internal.example.com, .corp.example.org",
+			assert: func(t *testing.T, got string) {
+				t.Helper()
+				for _, entry := range strings.Split(got, ", ") {
+					assert.True(t, strings.HasPrefix(entry, "."), "entry %q should keep its leading dot", entry)
+					assert.NotContains(t, entry, "example", "entry %q should not keep the original domain", entry)
+				}
+			},
+		},
+		{
+			name:      "any value name ending in Domain is treated as a domain",
+			valueName: "ICSDomain",
+			value:     "mshome.net",
+			assert: func(t *testing.T, got string) {
+				t.Helper()
+				assert.NotContains(t, got, "mshome", "should anonymize a domain suffix value")
+			},
+		},
+		{
+			name:      "search list is a comma separated domain list",
+			valueName: "SearchList",
+			value:     "corp.example.com,branch.example.com",
+			assert: func(t *testing.T, got string) {
+				t.Helper()
+				assert.NotContains(t, got, "example", "should anonymize every search domain")
+				assert.Len(t, strings.Split(got, ", "), 2, "should keep both search domains")
+			},
+		},
+		{
+			name:      "name servers are anonymized as addresses",
+			valueName: "DhcpNameServer",
+			value:     "203.0.113.10 8.8.8.8",
+			assert: func(t *testing.T, got string) {
+				t.Helper()
+				assert.NotContains(t, got, "203.0.113.10", "should anonymize a public resolver address")
+				// well-known resolvers stay readable at every level
+				assert.Contains(t, got, "8.8.8.8", "should keep a well-known resolver address")
+			},
+		},
+		{
+			name:      "opaque values are left to the string pass",
+			valueName: "DataBasePath",
+			value:     `%SystemRoot%\System32\drivers\etc`,
+			assert: func(t *testing.T, got string) {
+				t.Helper()
+				assert.Equal(t, `%SystemRoot%\System32\drivers\etc`, got, "should not alter a path")
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			g := newDNSValueGenerator(anonymize.LevelDefault)
+			tc.assert(t, g.anonymizeValue(tc.valueName, tc.value))
+		})
+	}
+}
+
+// TestParseNRPTPolicyTable parses the MOF text of the policy table out
+// parameters, as the provider on a client with one NRPT rule renders it.
+func TestParseNRPTPolicyTable(t *testing.T) {
+	const text = `[abstract]
+class __PARAMETERS
+{
+	[Out, EmbeddedInstance("DnsClientPolicyConfiguration"): ToSubClass, ID(2): DisableOverride ToInstance] DnsClientPolicyConfiguration cmdletOutput[] = {
+instance of DnsClientPolicyConfiguration
+{
+	DirectAccessProxyType = "NoProxy";
+	DirectAccessQueryIPsecRequired = FALSE;
+	NameEncoding = "Utf8WithoutMapping";
+	Namespace = ".0.100.in-addr.arpa";
+}, 
+instance of DnsClientPolicyConfiguration
+{
+	DirectAccessProxyType = "NoProxy";
+	NameEncoding = "Utf8WithoutMapping";
+	NameServers = {"100.0.255.254", "100.0.255.253"};
+	Namespace = ".nb.internal";
+}};
+	[in] boolean Effective;
+	[out] uint32 ReturnValue = 0;
+};
+`
+
+	entries := parseNRPTPolicyTable(text)
+	require.Len(t, entries, 2, "should parse both embedded instances")
+
+	assert.Equal(t, ".0.100.in-addr.arpa", entries[0].namespace, "should read the namespace of the first instance")
+	assert.Equal(t, ".nb.internal", entries[1].namespace, "should read the namespace of the second instance")
+
+	assert.Equal(t, []registryValue{
+		{name: "DirectAccessProxyType", value: "NoProxy"},
+		{name: "DirectAccessQueryIPsecRequired", value: "FALSE"},
+		{name: "NameEncoding", value: "Utf8WithoutMapping"},
+	}, entries[0].values, "should keep the remaining values in order")
+
+	assert.Contains(t, entries[1].values, registryValue{name: "NameServers", value: "100.0.255.254, 100.0.255.253"},
+		"should flatten a MOF array")
+
+	for _, value := range entries[1].values {
+		assert.NotContains(t, value.name, "ReturnValue", "should not read the class level parameters as values")
+	}
+}
+
+func TestParseNRPTPolicyTableEmpty(t *testing.T) {
+	assert.Empty(t, parseNRPTPolicyTable(""), "should parse no entries from empty text")
+	assert.Empty(t, parseNRPTPolicyTable("class __PARAMETERS\n{\n};\n"), "should parse no entries from a table with no instances")
+}

client/internal/debug/nrpt_windows.go

@@ -0,0 +1,317 @@
+//go:build windows
+
+package debug
+
+import (
+	"errors"
+	"fmt"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/go-ole/go-ole"
+	"github.com/go-ole/go-ole/oleutil"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	// The NRPT policy table is reachable through the CIM class that backs
+	// Get-DnsClientNrptPolicy. Unlike the rules in the registry, the table is
+	// what the resolver currently has loaded, which is the only way to tell an
+	// applied rule from one that is merely written, in either direction.
+	nrptPolicyNamespace = `root\Microsoft\Windows\DNS`
+	nrptPolicyClass     = "PS_DnsClientNrptPolicy"
+	nrptPolicyMethod    = "Get"
+
+	// The class has no instances, so the table comes from the out parameters
+	// of a static method call, rendered as MOF text: the embedded instances
+	// arrive as a safe array of objects, which cannot be read back through the
+	// COM bindings, and the text form carries all of them.
+	nrptPolicyInstanceKeyword = "instance of DnsClientPolicyConfiguration"
+
+	nrptPolicyTimeout = 15 * time.Second
+)
+
+// COM initialization results that leave the calling thread usable: S_FALSE for
+// a thread this process already initialized, RPC_E_CHANGED_MODE for one that
+// belongs to another apartment.
+const (
+	sFalse          = 0x00000001
+	rpcEChangedMode = 0x80010106
+)
+
+// nrptQueryInFlight admits one read of the policy table at a time. A provider
+// that stops answering keeps its goroutine and the OS thread that goroutine
+// pinned, so a later bundle reports that instead of pinning another one.
+var nrptQueryInFlight = make(chan struct{}, 1)
+
+// nrptPolicyEntry is one namespace of the effective policy table, holding the
+// values of an embedded DnsClientPolicyConfiguration instance in the order the
+// provider reported them.
+type nrptPolicyEntry struct {
+	namespace string
+	values    []registryValue
+}
+
+// registryValue is a name and its rendered value, shared by the registry and
+// policy table readers so both anonymize by value name the same way.
+type registryValue struct {
+	name  string
+	value string
+}
+
+// effectiveNRPTPolicies reads the effective NRPT table. The call is bounded
+// because a WMI provider can block indefinitely and a debug bundle must not.
+func effectiveNRPTPolicies() ([]nrptPolicyEntry, error) {
+	type result struct {
+		text string
+		err  error
+	}
+
+	select {
+	case nrptQueryInFlight <- struct{}{}:
+	default:
+		return nil, errors.New("an earlier read of the policy table has not returned")
+	}
+
+	done := make(chan result, 1)
+	go func() {
+		// the slot is released here rather than by the caller, so a read that
+		// outlives the timeout holds it until the provider answers
+		defer func() { <-nrptQueryInFlight }()
+
+		text, err := nrptPolicyTableText()
+		done <- result{text: text, err: err}
+	}()
+
+	select {
+	case res := <-done:
+		if res.err != nil {
+			return nil, res.err
+		}
+		return parseNRPTPolicyTable(res.text), nil
+	case <-time.After(nrptPolicyTimeout):
+		return nil, errors.New("read of the policy table timed out")
+	}
+}
+
+// nrptPolicyTableText calls the policy table method and returns the MOF text of
+// its out parameters.
+func nrptPolicyTableText() (text string, err error) {
+	// COM is per thread, and the collection is short lived, so the thread is
+	// pinned for the duration rather than initialized for the process.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	defer func() {
+		// The COM call chain is dynamically typed, so a provider that answers
+		// with an unexpected shape must not take the daemon down with it.
+		if r := recover(); r != nil {
+			err = fmt.Errorf("read NRPT policy table: %v", r)
+		}
+	}()
+
+	owns, err := coInitialize()
+	if err != nil {
+		return "", err
+	}
+	if owns {
+		defer ole.CoUninitialize()
+	}
+
+	locator, err := oleutil.CreateObject("WbemScripting.SWbemLocator")
+	if err != nil {
+		return "", fmt.Errorf("create WMI locator: %w", err)
+	}
+	defer locator.Release()
+
+	dispatch, err := locator.QueryInterface(ole.IID_IDispatch)
+	if err != nil {
+		return "", fmt.Errorf("query WMI locator interface: %w", err)
+	}
+	defer dispatch.Release()
+
+	service, err := dispatchCall(dispatch, "ConnectServer", nil, nrptPolicyNamespace)
+	if err != nil {
+		return "", fmt.Errorf("connect to %s: %w", nrptPolicyNamespace, err)
+	}
+	defer service.Release()
+
+	inParams, err := spawnMethodInParams(service)
+	if err != nil {
+		return "", err
+	}
+	defer inParams.Release()
+
+	// The effective table is the merge of the local and the group policy
+	// store, which is what the resolver answers from.
+	if _, err := oleutil.PutProperty(inParams, "Effective", true); err != nil {
+		return "", fmt.Errorf("set Effective parameter: %w", err)
+	}
+
+	outParams, err := dispatchCall(service, "ExecMethod", nrptPolicyClass, nrptPolicyMethod, inParams)
+	if err != nil {
+		return "", fmt.Errorf("call %s.%s: %w", nrptPolicyClass, nrptPolicyMethod, err)
+	}
+	defer outParams.Release()
+
+	textVariant, err := oleutil.CallMethod(outParams, "GetObjectText_")
+	if err != nil {
+		return "", fmt.Errorf("render policy table: %w", err)
+	}
+	defer func() {
+		if err := textVariant.Clear(); err != nil {
+			log.Debugf("clear policy table variant: %v", err)
+		}
+	}()
+
+	return textVariant.ToString(), nil
+}
+
+// spawnMethodInParams builds the in parameters instance the method needs. The
+// provider rejects the call without one, even when every parameter is optional.
+func spawnMethodInParams(service *ole.IDispatch) (*ole.IDispatch, error) {
+	class, err := dispatchCall(service, "Get", nrptPolicyClass)
+	if err != nil {
+		return nil, fmt.Errorf("get class %s: %w", nrptPolicyClass, err)
+	}
+	defer class.Release()
+
+	methods, err := dispatchProperty(class, "Methods_")
+	if err != nil {
+		return nil, fmt.Errorf("get class methods: %w", err)
+	}
+	defer methods.Release()
+
+	method, err := dispatchCall(methods, "Item", nrptPolicyMethod)
+	if err != nil {
+		return nil, fmt.Errorf("get method %s: %w", nrptPolicyMethod, err)
+	}
+	defer method.Release()
+
+	params, err := dispatchProperty(method, "InParameters")
+	if err != nil {
+		return nil, fmt.Errorf("get method parameters: %w", err)
+	}
+	defer params.Release()
+
+	inParams, err := dispatchCall(params, "SpawnInstance_")
+	if err != nil {
+		return nil, fmt.Errorf("spawn parameter instance: %w", err)
+	}
+
+	return inParams, nil
+}
+
+// parseNRPTPolicyTable pulls the embedded instances out of the MOF text. Each
+// instance is a namespace of the table, with one name and value per line.
+func parseNRPTPolicyTable(text string) []nrptPolicyEntry {
+	var entries []nrptPolicyEntry
+	var current *nrptPolicyEntry
+
+	for _, line := range strings.Split(text, "\n") {
+		line = strings.TrimSpace(strings.TrimSuffix(strings.TrimSpace(line), ";"))
+
+		switch {
+		case strings.HasPrefix(line, nrptPolicyInstanceKeyword):
+			entries = append(entries, nrptPolicyEntry{})
+			current = &entries[len(entries)-1]
+			continue
+		case strings.HasPrefix(line, "}"):
+			// closes an instance, and the array with the last one, so the
+			// class level parameters that follow are not read as values
+			current = nil
+			continue
+		case current == nil, line == "{":
+			continue
+		}
+
+		name, value, ok := strings.Cut(line, " = ")
+		if !ok {
+			continue
+		}
+
+		value = unquoteMOFValue(value)
+		if name == "Namespace" {
+			current.namespace = value
+			continue
+		}
+
+		current.values = append(current.values, registryValue{name: name, value: value})
+	}
+
+	return entries
+}
+
+// unquoteMOFValue renders a MOF scalar or array as plain text: "a" becomes a,
+// and {"a", "b"} becomes a, b.
+func unquoteMOFValue(value string) string {
+	value = strings.TrimSpace(value)
+
+	if inner, ok := strings.CutPrefix(value, "{"); ok {
+		value = strings.TrimSuffix(inner, "}")
+
+		entries := strings.Split(value, ",")
+		for i, entry := range entries {
+			entries[i] = strings.Trim(strings.TrimSpace(entry), `"`)
+		}
+		return strings.Join(entries, ", ")
+	}
+
+	return strings.Trim(value, `"`)
+}
+
+// coInitialize prepares the calling thread for COM and reports whether this
+// call owns the initialization, which decides whether it may be balanced with
+// CoUninitialize. S_FALSE took a reference on a thread this process had already
+// initialized and so has to be released, while RPC_E_CHANGED_MODE took none:
+// the thread belongs to another apartment, which is usable but is not ours to
+// uninitialize.
+func coInitialize() (bool, error) {
+	err := ole.CoInitializeEx(0, ole.COINIT_MULTITHREADED)
+	if err == nil {
+		return true, nil
+	}
+
+	var oleErr *ole.OleError
+	if errors.As(err, &oleErr) {
+		switch oleErr.Code() {
+		case sFalse:
+			return true, nil
+		case rpcEChangedMode:
+			return false, nil
+		}
+	}
+
+	return false, fmt.Errorf("initialize COM: %w", err)
+}
+
+// dispatchCall calls a COM method that returns an object.
+func dispatchCall(dispatch *ole.IDispatch, method string, params ...any) (*ole.IDispatch, error) {
+	variant, err := oleutil.CallMethod(dispatch, method, params...)
+	if err != nil {
+		return nil, err
+	}
+
+	object := variant.ToIDispatch()
+	if object == nil {
+		return nil, fmt.Errorf("%s returned no object", method)
+	}
+
+	return object, nil
+}
+
+// dispatchProperty reads a COM property that holds an object.
+func dispatchProperty(dispatch *ole.IDispatch, property string) (*ole.IDispatch, error) {
+	variant, err := oleutil.GetProperty(dispatch, property)
+	if err != nil {
+		return nil, err
+	}
+
+	object := variant.ToIDispatch()
+	if object == nil {
+		return nil, fmt.Errorf("property %s holds no object", property)
+	}
+
+	return object, nil
+}

client/internal/debug/uilog_test.go

@@ -0,0 +1,64 @@
+package debug
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/configs"
+)
+
+// bundleEntries generates a bundle with the given generator and returns the
+// set of entry names in the resulting archive.
+func bundleEntries(t *testing.T, g *BundleGenerator) map[string]struct{} {
+	t.Helper()
+
+	path, err := g.Generate()
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = os.Remove(path) })
+
+	data, err := os.ReadFile(path)
+	require.NoError(t, err)
+
+	zr, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
+	require.NoError(t, err)
+
+	names := make(map[string]struct{}, len(zr.File))
+	for _, f := range zr.File {
+		names[f.Name] = struct{}{}
+	}
+	return names
+}
+
+func TestBundleIncludesUILogWhenOpenerAllows(t *testing.T) {
+	path := filepath.Join(t.TempDir(), configs.UILogFile)
+	require.NoError(t, os.WriteFile(path, []byte("gui log"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath:   path,
+		UILogOpener: openLogFile,
+	}, BundleConfig{})
+
+	require.Contains(t, bundleEntries(t, g), configs.UILogFile)
+}
+
+// A UILogOpener that refuses (as the ownership check does for a foreign file)
+// keeps the UI log out of the bundle without failing bundle generation.
+func TestBundleExcludesUILogWhenOpenerRefuses(t *testing.T) {
+	path := filepath.Join(t.TempDir(), configs.UILogFile)
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath: path,
+		UILogOpener: func(string) (*os.File, error) {
+			return nil, fmt.Errorf("not owned by the caller")
+		},
+	}, BundleConfig{})
+
+	require.NotContains(t, bundleEntries(t, g), configs.UILogFile)
+}

client/internal/debug/upload.go

@@ -3,10 +3,12 @@ package debug
 import (
 	"context"
 	"crypto/sha256"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
+	neturl "net/url"
 	"os"
 
 	"github.com/netbirdio/netbird/upload-server/types"
@@ -14,20 +16,80 @@ import (
 
 const maxBundleUploadSize = 50 * 1024 * 1024
 
-func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string) (key string, err error) {
-	response, err := getUploadURL(ctx, url, managementURL)
+// requireHTTPS refuses any URL the daemon would fetch or upload to that is not
+// https. The daemon runs as root and the bundle carries its logs and state, so a
+// plaintext hop is a place to intercept the bundle or the presigned redirect.
+// The server-side gate already enforces this for the desktop path; this also
+// covers the mobile and job-runner callers that reach this package directly.
+// Skipped when the caller opted into an insecure upload (self-hosted server).
+func requireHTTPS(what, rawURL string) error {
+	parsed, err := neturl.Parse(rawURL)
+	if err != nil {
+		return fmt.Errorf("parse %s: %w", what, err)
+	}
+	if parsed.Scheme != "https" {
+		return fmt.Errorf("%s must use https, got scheme %q", what, parsed.Scheme)
+	}
+	return nil
+}
+
+// uploadClient returns the HTTP client for the upload requests. The default
+// client verifies TLS and refuses a redirect that would downgrade to a non-https
+// hop, so a bundle can never leave over http after an https start. The insecure
+// variant accepts http and untrusted certificates, and is only reachable for a
+// privileged caller that passed --upload-bundle-insecure (see
+// requirePrivilegeForUploadURL).
+func uploadClient(insecure bool) *http.Client {
+	if !insecure {
+		return &http.Client{CheckRedirect: rejectInsecureRedirect}
+	}
+	return &http.Client{
+		Transport: &http.Transport{
+			//nolint:gosec // opt-in, privileged, self-hosted upload servers
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true, MinVersion: tls.VersionTLS12},
+		},
+	}
+}
+
+// rejectInsecureRedirect refuses a redirect to a non-https target and keeps the
+// standard library's 10-hop limit that a custom CheckRedirect would otherwise
+// disable.
+func rejectInsecureRedirect(req *http.Request, via []*http.Request) error {
+	if req.URL.Scheme != "https" {
+		return fmt.Errorf("refusing redirect to non-https URL %s", req.URL.Redacted())
+	}
+	if len(via) >= 10 {
+		return fmt.Errorf("stopped after 10 redirects")
+	}
+	return nil
+}
+
+func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string, insecure bool) (key string, err error) {
+	if !insecure {
+		if err := requireHTTPS("upload service URL", url); err != nil {
+			return "", err
+		}
+	}
+
+	response, err := getUploadURL(ctx, url, managementURL, insecure)
 	if err != nil {
 		return "", err
 	}
 
-	err = upload(ctx, filePath, response)
+	if !insecure {
+		if err := requireHTTPS("upload URL from service", response.URL); err != nil {
+			return "", err
+		}
+	}
+
+	err = upload(ctx, filePath, response, insecure)
 	if err != nil {
 		return "", err
 	}
 	return response.Key, nil
 }
 
-func upload(ctx context.Context, filePath string, response *types.GetURLResponse) error {
+func upload(ctx context.Context, filePath string, response *types.GetURLResponse, insecure bool) error {
 	fileData, err := os.Open(filePath)
 	if err != nil {
 		return fmt.Errorf("open file: %w", err)
@@ -52,7 +114,7 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	req.ContentLength = stat.Size()
 	req.Header.Set("Content-Type", "application/octet-stream")
 
-	putResp, err := http.DefaultClient.Do(req)
+	putResp, err := uploadClient(insecure).Do(req)
 	if err != nil {
 		return fmt.Errorf("upload failed: %v", err)
 	}
@@ -65,16 +127,23 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	return nil
 }
 
-func getUploadURL(ctx context.Context, url string, managementURL string) (*types.GetURLResponse, error) {
-	id := getURLHash(managementURL)
-	getReq, err := http.NewRequestWithContext(ctx, "GET", url+"?id="+id, nil)
+func getUploadURL(ctx context.Context, serviceURL string, managementURL string, insecure bool) (*types.GetURLResponse, error) {
+	parsed, err := neturl.Parse(serviceURL)
+	if err != nil {
+		return nil, fmt.Errorf("parse upload service URL: %w", err)
+	}
+	q := parsed.Query()
+	q.Set("id", getURLHash(managementURL))
+	parsed.RawQuery = q.Encode()
+
+	getReq, err := http.NewRequestWithContext(ctx, "GET", parsed.String(), nil)
 	if err != nil {
 		return nil, fmt.Errorf("create GET request: %w", err)
 	}
 
 	getReq.Header.Set(types.ClientHeader, types.ClientHeaderValue)
 
-	resp, err := http.DefaultClient.Do(getReq)
+	resp, err := uploadClient(insecure).Do(getReq)
 	if err != nil {
 		return nil, fmt.Errorf("get presigned URL: %w", err)
 	}

client/internal/debug/upload_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"net"
 	"net/http"
+	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"testing"
@@ -43,7 +44,7 @@ func TestUpload(t *testing.T) {
 	fileContent := []byte("test file content")
 	err := os.WriteFile(file, fileContent, 0640)
 	require.NoError(t, err)
-	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file)
+	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file, true)
 	require.NoError(t, err)
 	id := getURLHash(testURL)
 	require.Contains(t, key, id+"/")
@@ -79,3 +80,47 @@ func waitForServer(t *testing.T, addr string) {
 	}
 	t.Fatalf("server did not start listening on %s in time", addr)
 }
+
+func TestRequireHTTPS(t *testing.T) {
+	require.NoError(t, requireHTTPS("upload URL", "https://upload.example/path"))
+	require.Error(t, requireHTTPS("upload URL", "http://upload.example/path"))
+	require.Error(t, requireHTTPS("upload URL", "ftp://upload.example/path"))
+	require.Error(t, requireHTTPS("upload URL", "://malformed"))
+}
+
+func TestRejectInsecureRedirect(t *testing.T) {
+	httpsReq, err := http.NewRequest(http.MethodGet, "https://a.example/", nil)
+	require.NoError(t, err)
+	require.NoError(t, rejectInsecureRedirect(httpsReq, nil), "https redirect target must be allowed")
+
+	httpReq, err := http.NewRequest(http.MethodGet, "http://a.example/", nil)
+	require.NoError(t, err)
+	require.Error(t, rejectInsecureRedirect(httpReq, nil), "http redirect target must be refused")
+
+	require.Error(t, rejectInsecureRedirect(httpsReq, make([]*http.Request, 10)), "the 10-redirect limit must be enforced")
+}
+
+// The secure client refuses to follow an https response that redirects to http,
+// so a bundle can't be downgraded onto plaintext mid-flight.
+func TestUploadClientRefusesHTTPSToHTTPRedirect(t *testing.T) {
+	plain := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+	t.Cleanup(plain.Close)
+
+	secure := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, plain.URL, http.StatusFound)
+	}))
+	t.Cleanup(secure.Close)
+
+	client := uploadClient(false)
+	// Trust the test server's cert without disabling verification globally.
+	client.Transport = secure.Client().Transport
+
+	resp, err := client.Get(secure.URL)
+	if resp != nil {
+		_ = resp.Body.Close()
+	}
+	require.Error(t, err, "redirect from https to http must be refused")
+	require.Contains(t, err.Error(), "non-https")
+}

client/internal/debug/wgshow.go

@@ -35,14 +35,14 @@ func (g *BundleGenerator) toWGShowFormat(s *configurer.Stats) string {
 	var sb strings.Builder
 
 	sb.WriteString(fmt.Sprintf("interface: %s\n", s.DeviceName))
-	sb.WriteString(fmt.Sprintf("  public key: %s\n", s.PublicKey))
+	sb.WriteString(fmt.Sprintf("  public key: %s\n", g.anonymizer.AnonymizeWGKey(s.PublicKey)))
 	sb.WriteString(fmt.Sprintf("  listen port: %d\n", s.ListenPort))
 	if s.FWMark != 0 {
 		sb.WriteString(fmt.Sprintf("  fwmark: %#x\n", s.FWMark))
 	}
 
 	for _, peer := range s.Peers {
-		sb.WriteString(fmt.Sprintf("\npeer: %s\n", peer.PublicKey))
+		sb.WriteString(fmt.Sprintf("\npeer: %s\n", g.anonymizer.AnonymizeWGKey(peer.PublicKey)))
 		if peer.Endpoint.IP != nil {
 			if g.anonymize {
 				anonEndpoint := g.anonymizer.AnonymizeUDPAddr(peer.Endpoint)
@@ -54,7 +54,11 @@ func (g *BundleGenerator) toWGShowFormat(s *configurer.Stats) string {
 		if len(peer.AllowedIPs) > 0 {
 			var ipStrings []string
 			for _, ipnet := range peer.AllowedIPs {
-				ipStrings = append(ipStrings, ipnet.String())
+				ipStr := ipnet.String()
+				if g.anonymize {
+					ipStr = g.anonymizer.AnonymizeIPString(ipStr)
+				}
+				ipStrings = append(ipStrings, ipStr)
 			}
 			sb.WriteString(fmt.Sprintf("  allowed ips: %s\n", strings.Join(ipStrings, ", ")))
 		}

client/internal/dns/host_darwin.go

@@ -267,18 +267,38 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 		return SystemDNSSettings{}, fmt.Errorf("sending the command: %w", err)
 	}
 
-	var dnsSettings SystemDNSSettings
+	dnsSettings, serverAddresses, err := parseSystemDNSSettings(b)
+	if err != nil {
+		return dnsSettings, err
+	}
+
+	s.mu.Lock()
+	s.origNameservers = serverAddresses
+	s.mu.Unlock()
+
+	return dnsSettings, nil
+}
+
+// parseSystemDNSSettings parses the output of `scutil show State:/Network/Service/<id>/DNS`.
+// Lines that don't match the expected "index : value" shape are skipped: hosts with unusual
+// network services (e.g. orphaned hardware ports) can produce entries without a value.
+func parseSystemDNSSettings(out []byte) (SystemDNSSettings, []netip.Addr, error) {
+	// port is not exposed by scutil, default to 53
+	dnsSettings := SystemDNSSettings{ServerPort: DefaultPort}
 	var serverAddresses []netip.Addr
 	inSearchDomainsArray := false
 	inServerAddressesArray := false
 
-	scanner := bufio.NewScanner(bytes.NewReader(b))
+	scanner := bufio.NewScanner(bytes.NewReader(out))
 	for scanner.Scan() {
 		line := strings.TrimSpace(scanner.Text())
 		switch {
 		case strings.HasPrefix(line, "DomainName :"):
-			domainName := strings.TrimSpace(strings.Split(line, ":")[1])
-			dnsSettings.Domains = append(dnsSettings.Domains, domainName)
+			domainName := strings.TrimSpace(strings.TrimPrefix(line, "DomainName :"))
+			if domainName != "" {
+				dnsSettings.Domains = append(dnsSettings.Domains, domainName)
+			}
+			continue
 		case line == "SearchDomains : <array> {":
 			inSearchDomainsArray = true
 			continue
@@ -288,36 +308,45 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 		case line == "}":
 			inSearchDomainsArray = false
 			inServerAddressesArray = false
+			continue
+		}
+
+		if !inSearchDomainsArray && !inServerAddressesArray {
+			continue
+		}
+
+		parts := strings.SplitN(line, " : ", 2)
+		if len(parts) != 2 {
+			log.Debugf("skipping unexpected scutil DNS line %q", line)
+			continue
+		}
+		value := strings.TrimSpace(parts[1])
+		if value == "" {
+			continue
 		}
 
 		if inSearchDomainsArray {
-			searchDomain := strings.Split(line, " : ")[1]
-			dnsSettings.Domains = append(dnsSettings.Domains, searchDomain)
-		} else if inServerAddressesArray {
-			address := strings.Split(line, " : ")[1]
-			if ip, err := netip.ParseAddr(address); err == nil && !ip.IsUnspecified() {
-				ip = ip.Unmap()
-				serverAddresses = append(serverAddresses, ip)
-				// Prefer the first IPv4 server as ServerIP since our DNS listener is IPv4.
-				if !dnsSettings.ServerIP.IsValid() && ip.Is4() {
-					dnsSettings.ServerIP = ip
-				}
-			}
+			dnsSettings.Domains = append(dnsSettings.Domains, value)
+			continue
+		}
+
+		ip, err := netip.ParseAddr(value)
+		if err != nil || ip.IsUnspecified() {
+			continue
+		}
+		ip = ip.Unmap()
+		serverAddresses = append(serverAddresses, ip)
+		// Prefer the first IPv4 server as ServerIP since our DNS listener is IPv4.
+		if !dnsSettings.ServerIP.IsValid() && ip.Is4() {
+			dnsSettings.ServerIP = ip
 		}
 	}
 
 	if err := scanner.Err(); err != nil {
-		return dnsSettings, err
+		return dnsSettings, serverAddresses, err
 	}
 
-	// default to 53 port
-	dnsSettings.ServerPort = DefaultPort
-
-	s.mu.Lock()
-	s.origNameservers = serverAddresses
-	s.mu.Unlock()
-
-	return dnsSettings, nil
+	return dnsSettings, serverAddresses, nil
 }
 
 func (s *systemConfigurator) getOriginalNameservers() []netip.Addr {
@@ -435,11 +464,15 @@ func (s *systemConfigurator) getPrimaryService() (string, string, error) {
 	router := ""
 	for scanner.Scan() {
 		text := scanner.Text()
+		parts := strings.SplitN(text, ":", 2)
+		if len(parts) != 2 {
+			continue
+		}
 		if strings.Contains(text, "PrimaryService") {
-			primaryService = strings.TrimSpace(strings.Split(text, ":")[1])
+			primaryService = strings.TrimSpace(parts[1])
 		}
 		if strings.Contains(text, "Router") {
-			router = strings.TrimSpace(strings.Split(text, ":")[1])
+			router = strings.TrimSpace(parts[1])
 		}
 	}
 	if err := scanner.Err(); err != nil && err != io.EOF {