Merge main

client/mdm/canonical_loaders.go

@@ -0,0 +1,50 @@
+//go:build windows || darwin
+
+package mdm
+
+import "strings"
+
+// allKeys is the set of recognised MDM keys. Unknown keys in a managed
+// configuration are ignored but logged. Lives in this build-tagged file
+// (windows || darwin) because only desktop loaders need the
+// canonicalisation table that consumes it; including it unconditionally
+// would trigger the `unused` golangci-lint check on platforms that
+// don't import canonical_loaders.go.
+var allKeys = []string{
+	KeyManagementURL,
+	KeyDisableUpdateSettings,
+	KeyDisableProfiles,
+	KeyDisableNetworks,
+	KeyDisableClientRoutes,
+	KeyDisableServerRoutes,
+	KeyBlockInbound,
+	KeyDisableMetricsCollection,
+	KeyAllowServerSSH,
+	KeyDisableAutoConnect,
+	KeyPreSharedKey,
+	KeyRosenpassEnabled,
+	KeyRosenpassPermissive,
+	KeyWireguardPort,
+	KeySplitTunnelMode,
+	KeySplitTunnelApps,
+}
+
+// canonicalKey maps the lowercase form of a managed-config value name to
+// its canonical mdm.Key* form. Admins commonly write PascalCase value
+// names in ADMX / Group Policy ("ManagementURL"); the iOS/AppConfig and
+// macOS plist conventions are camelCase ("managementURL"); both must
+// resolve to the same Policy lookup.
+//
+// Lives in a desktop-loader-only file (build tag `windows || darwin`)
+// because no other build path consumes it. Linux / FreeBSD / mobile
+// builds don't ship a platform loader that reads arbitrary-case key
+// names, so they don't need the canonicalisation table — and including
+// the var unconditionally would trigger the `unused` golangci-lint
+// check on those platforms.
+var canonicalKey = func() map[string]string {
+	m := make(map[string]string, len(allKeys))
+	for _, k := range allKeys {
+		m[strings.ToLower(k)] = k
+	}
+	return m
+}()

client/mdm/policy.go

@@ -0,0 +1,246 @@
+// Package mdm reads MDM-managed configuration from platform-native sources
+// (plist on macOS, registry on Windows, UserDefaults on iOS,
+// RestrictionsManager on Android). The returned Policy is consumed by
+// profilemanager.Config.apply() as the highest-priority override layer.
+//
+// An empty Policy (no source present, or source present with zero keys)
+// means no MDM enforcement is active and the client behaves as if the
+// feature did not exist.
+package mdm
+
+import (
+	"sort"
+	"strconv"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// Well-known policy keys. Names mirror the corresponding ConfigInput Go field
+// names (lowerCamelCase) so the daemon can map a Policy key directly to a
+// configuration field.
+const (
+	KeyManagementURL            = "managementURL"
+	KeyDisableUpdateSettings    = "disableUpdateSettings"
+	KeyDisableProfiles          = "disableProfiles"
+	KeyDisableNetworks          = "disableNetworks"
+	KeyDisableClientRoutes      = "disableClientRoutes"
+	KeyDisableServerRoutes      = "disableServerRoutes"
+	KeyBlockInbound             = "blockInbound"
+	KeyDisableMetricsCollection = "disableMetricsCollection"
+	KeyAllowServerSSH           = "allowServerSSH"
+	KeyDisableAutoConnect       = "disableAutoConnect"
+	KeyPreSharedKey             = "preSharedKey"
+	KeyRosenpassEnabled         = "rosenpassEnabled"
+	KeyRosenpassPermissive      = "rosenpassPermissive"
+	KeyWireguardPort            = "wireguardPort"
+
+	// Split tunnel is modeled as a single conceptual policy with two
+	// registry/plist values. KeySplitTunnelMode is the discriminator
+	// ("allow" or "disallow"); KeySplitTunnelApps is a comma-separated
+	// list of package names. The values are mutually exclusive by
+	// construction — only one mode can be set at a time.
+	KeySplitTunnelMode = "splitTunnelMode"
+	KeySplitTunnelApps = "splitTunnelApps"
+)
+
+// Split-tunnel mode literals (KeySplitTunnelMode values).
+const (
+	SplitTunnelModeAllow    = "allow"
+	SplitTunnelModeDisallow = "disallow"
+)
+
+// SecretKeys lists keys whose values must be redacted in logs.
+var SecretKeys = map[string]struct{}{
+	KeyPreSharedKey: {},
+}
+
+// boolStringLiterals enumerates the textual boolean encodings the
+// platform loaders may produce (Windows REG_SZ "true", iOS / Android
+// managed-config booleans-as-strings, etc.). Lookup keeps GetBool flat
+// (no nested switch on the string case).
+var boolStringLiterals = map[string]bool{
+	"true":  true,
+	"1":     true,
+	"yes":   true,
+	"false": false,
+	"0":     false,
+	"no":    false,
+}
+
+// Policy holds MDM-managed settings read from the platform source. A nil or
+// empty Policy means no enforcement is active.
+type Policy struct {
+	values map[string]any
+}
+
+// NewPolicy constructs a Policy from a key→value map. Pass nil or an
+// empty map to construct an empty (no-enforcement) Policy. The returned
+// *Policy is always non-nil.
+func NewPolicy(values map[string]any) *Policy {
+	if values == nil {
+		values = map[string]any{}
+	}
+	return &Policy{values: values}
+}
+
+// LoadPolicy reads the platform-native MDM configuration. Returns an
+// empty (but non-nil) Policy when no source is present, the source is
+// empty, or the platform is unsupported.
+//
+// Diagnostic logging differentiates the three states:
+//   - source absent / unsupported platform: trace log only
+//   - source present, zero keys:             info "MDM enrolled (no managed keys)"
+//   - source present, N keys:                info "MDM enrolled with N managed keys: [...]"
+func LoadPolicy() *Policy {
+	values, err := loadPlatformPolicy()
+	if err != nil {
+		log.Tracef("MDM policy load: %v", err)
+		return &Policy{values: map[string]any{}}
+	}
+	if values == nil {
+		return &Policy{values: map[string]any{}}
+	}
+	if len(values) == 0 {
+		log.Info("MDM enrolled (no managed keys)")
+	} else {
+		log.Infof("MDM enrolled with %d managed key(s): %v", len(values), sortedKeys(values))
+	}
+	return &Policy{values: values}
+}
+
+// IsEmpty reports whether the Policy has no managed keys.
+func (p *Policy) IsEmpty() bool {
+	return p == nil || len(p.values) == 0
+}
+
+// HasKey reports whether the given key is MDM-managed.
+func (p *Policy) HasKey(key string) bool {
+	if p == nil {
+		return false
+	}
+	_, ok := p.values[key]
+	return ok
+}
+
+// ManagedKeys returns the sorted list of managed key names. Returns an empty
+// slice (not nil) on an empty Policy.
+func (p *Policy) ManagedKeys() []string {
+	if p == nil {
+		return []string{}
+	}
+	return sortedKeys(p.values)
+}
+
+// GetString returns the managed value for key coerced to string, and whether
+// the key was set. A non-string value returns ("", false).
+func (p *Policy) GetString(key string) (string, bool) {
+	if p == nil {
+		return "", false
+	}
+	v, ok := p.values[key]
+	if !ok {
+		return "", false
+	}
+	s, ok := v.(string)
+	if !ok || s == "" {
+		return "", false
+	}
+	return s, true
+}
+
+// GetBool returns the managed value for key coerced to bool, and whether the
+// key was set. Accepts native bool and string literals "true"/"false"/"1"/"0".
+func (p *Policy) GetBool(key string) (bool, bool) {
+	if p == nil {
+		return false, false
+	}
+	v, ok := p.values[key]
+	if !ok {
+		return false, false
+	}
+	switch t := v.(type) {
+	case bool:
+		return t, true
+	case string:
+		b, known := boolStringLiterals[t]
+		return b, known
+	case int:
+		return t != 0, true
+	case int64:
+		return t != 0, true
+	}
+	return false, false
+}
+
+// GetInt returns the managed value for key as int64, and whether the key
+// was set. Accepts native int / int64 (as produced by the Windows registry
+// loader for REG_DWORD/REG_QWORD) and numeric strings (decimal).
+func (p *Policy) GetInt(key string) (int64, bool) {
+	if p == nil {
+		return 0, false
+	}
+	v, ok := p.values[key]
+	if !ok {
+		return 0, false
+	}
+	switch t := v.(type) {
+	case int64:
+		return t, true
+	case int:
+		return int64(t), true
+	case int32:
+		return int64(t), true
+	case uint64:
+		return int64(t), true
+	case float64:
+		return int64(t), true
+	case string:
+		if n, err := strconv.ParseInt(t, 10, 64); err == nil {
+			return n, true
+		}
+	}
+	return 0, false
+}
+
+// GetStringSlice returns the managed value for key as []string, and whether
+// the key was set. Accepts []string, []any (of strings), and a single string
+// (treated as a one-element list).
+func (p *Policy) GetStringSlice(key string) ([]string, bool) {
+	if p == nil {
+		return nil, false
+	}
+	v, ok := p.values[key]
+	if !ok {
+		return nil, false
+	}
+	switch t := v.(type) {
+	case []string:
+		return append([]string(nil), t...), true
+	case []any:
+		out := make([]string, 0, len(t))
+		for _, item := range t {
+			s, ok := item.(string)
+			if !ok {
+				return nil, false
+			}
+			out = append(out, s)
+		}
+		return out, true
+	case string:
+		return []string{t}, true
+	}
+	return nil, false
+}
+
+// sortedKeys returns the keys of m as a deterministic, lexicographically
+// sorted slice. Used internally by Policy.ManagedKeys and LoadPolicy's
+// diagnostic log line so callers see a stable key order across runs
+// regardless of Go's randomised map iteration.
+func sortedKeys(m map[string]any) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}

client/mdm/policy_darwin.go

@@ -0,0 +1,90 @@
+//go:build darwin && !ios
+
+package mdm
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	"howett.net/plist"
+)
+
+// policyPlistPath is the well-known location where macOS writes the
+// device-level mandatory MDM payload for NetBird. The path is fixed by
+// Apple convention: when an MDM provider (Jamf / Kandji / Mosyle /
+// Intune for Mac / Workspace ONE) pushes a Configuration Profile that
+// contains a com.apple.ManagedClient.preferences payload targeting the
+// bundle id io.netbird.client, the OS materializes the payload here.
+//
+// Read-only — only the OS (root) is supposed to write this file. The
+// loader sanity-checks the file mode and refuses to honour a world-
+// writable plist, as a defense against tampered installs.
+const policyPlistPath = "/Library/Managed Preferences/io.netbird.client.plist"
+
+// loadPlatformPolicy reads the MDM-managed configuration from the macOS
+// managed-preferences plist at policyPlistPath. Returns:
+//   - (nil, nil)  when the plist is absent (device not MDM-enrolled for
+//     NetBird, or admin has not yet pushed a payload)
+//   - (map, nil)  with N entries when N managed values are present
+//     (N may be 0 — empty plist still signals enrollment to the caller)
+//   - (nil, err)  on permission / parse / safety errors (including
+//     refusal to read a world-writable plist)
+//
+// Top-level plist keys are canonicalised case-insensitively to the
+// package's internal mdm.Key* names; unknown keys are logged and
+// skipped so a stray entry in the payload does not block startup.
+// Native plist value types map naturally onto the Policy accessor
+// expectations (GetString / GetBool / GetInt / GetStringSlice).
+func loadPlatformPolicy() (map[string]any, error) {
+	f, err := os.Open(policyPlistPath)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			// Not enrolled for NetBird. Caller treats nil as
+			// "no MDM source present".
+			//nolint:nilnil // (nil, nil) is the documented platform-absent sentinel; see LoadPolicy.
+			return nil, nil
+		}
+		return nil, fmt.Errorf("open %s: %w", policyPlistPath, err)
+	}
+	defer func() {
+		if closeErr := f.Close(); closeErr != nil {
+			log.Warnf("MDM close plist %s: %v", policyPlistPath, closeErr)
+		}
+	}()
+
+	info, err := f.Stat()
+	if err != nil {
+		return nil, fmt.Errorf("stat %s: %w", policyPlistPath, err)
+	}
+	// World-writable plist => tampered install. Refuse rather than
+	// honour potentially attacker-controlled policy values.
+	if info.Mode().Perm()&0o002 != 0 {
+		return nil, fmt.Errorf("refusing to read world-writable MDM source %s (mode %o)",
+			policyPlistPath, info.Mode().Perm())
+	}
+
+	raw := make(map[string]any)
+	if err := plist.NewDecoder(f).Decode(&raw); err != nil {
+		return nil, fmt.Errorf("decode plist %s: %w", policyPlistPath, err)
+	}
+
+	out := make(map[string]any, len(raw))
+	for name, val := range raw {
+		// macOS / AppConfig conventions both use camelCase for managed
+		// preferences keys; canonicalize to the mdm.Key* form so a key
+		// written as "ManagementURL" (PascalCase, rare on macOS but
+		// possible if the admin reused an ADMX-style name) still
+		// resolves.
+		canonical, known := canonicalKey[strings.ToLower(name)]
+		if !known {
+			log.Warnf("MDM ignoring unknown plist key %s: %s", policyPlistPath, name)
+			continue
+		}
+		out[canonical] = val
+	}
+	return out, nil
+}

client/mdm/policy_mobile.go

@@ -0,0 +1,14 @@
+//go:build ios || android
+
+package mdm
+
+// loadPlatformPolicy is unused on mobile: the native layer (Swift on iOS,
+// Kotlin/Java on Android) reads the OS managed-config store and pushes the
+// resulting dictionary in-process via a gomobile entry point that lands in
+// Phase 5 / Phase 6. The stub keeps the package compilable for mobile
+// builds and returns (nil, nil) — the platform-absent sentinel that
+// LoadPolicy in policy.go treats as "no MDM source present".
+func loadPlatformPolicy() (map[string]any, error) {
+	//nolint:nilnil // (nil, nil) is the documented platform-absent sentinel; see LoadPolicy.
+	return nil, nil
+}

client/mdm/policy_other.go

@@ -0,0 +1,14 @@
+//go:build !windows && !darwin && !ios && !android
+
+package mdm
+
+// loadPlatformPolicy returns no policy on platforms without an MDM channel
+// (Linux, FreeBSD). MDM enforcement is off and the client behaves as if
+// the feature did not exist. Returns (nil, nil) — the platform-absent
+// sentinel the caller (LoadPolicy in policy.go) treats as "no MDM
+// source present"; an error here would just translate to the same
+// outcome with an extra log line.
+func loadPlatformPolicy() (map[string]any, error) {
+	//nolint:nilnil // (nil, nil) is the documented platform-absent sentinel; see LoadPolicy.
+	return nil, nil
+}

client/mdm/policy_test.go

@@ -0,0 +1,160 @@
+package mdm
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPolicy_NilSafe(t *testing.T) {
+	var p *Policy
+	assert.True(t, p.IsEmpty())
+	assert.False(t, p.HasKey(KeyManagementURL))
+	assert.Empty(t, p.ManagedKeys())
+
+	_, ok := p.GetString(KeyManagementURL)
+	assert.False(t, ok)
+	_, ok = p.GetBool(KeyDisableProfiles)
+	assert.False(t, ok)
+	_, ok = p.GetStringSlice(KeySplitTunnelApps)
+	assert.False(t, ok)
+}
+
+func TestPolicy_Empty(t *testing.T) {
+	p := NewPolicy(nil)
+	require.NotNil(t, p)
+	assert.True(t, p.IsEmpty())
+	assert.False(t, p.HasKey(KeyManagementURL))
+	assert.Empty(t, p.ManagedKeys())
+}
+
+func TestPolicy_HasKey(t *testing.T) {
+	p := NewPolicy(map[string]any{
+		KeyManagementURL:   "https://corp.example.com",
+		KeyDisableProfiles: true,
+	})
+	assert.False(t, p.IsEmpty())
+	assert.True(t, p.HasKey(KeyManagementURL))
+	assert.True(t, p.HasKey(KeyDisableProfiles))
+	assert.False(t, p.HasKey(KeyPreSharedKey))
+}
+
+func TestPolicy_ManagedKeysSorted(t *testing.T) {
+	p := NewPolicy(map[string]any{
+		KeyDisableProfiles: true,
+		KeyManagementURL:   "https://x",
+		KeyAllowServerSSH:  false,
+	})
+	got := p.ManagedKeys()
+	assert.Equal(t, []string{KeyAllowServerSSH, KeyDisableProfiles, KeyManagementURL}, got)
+}
+
+func TestPolicy_GetString(t *testing.T) {
+	p := NewPolicy(map[string]any{
+		KeyManagementURL:   "https://corp.example.com",
+		KeyDisableProfiles: true, // wrong type for GetString
+		KeyPreSharedKey:    "",   // empty rejected
+	})
+	v, ok := p.GetString(KeyManagementURL)
+	assert.True(t, ok)
+	assert.Equal(t, "https://corp.example.com", v)
+
+	_, ok = p.GetString(KeyDisableProfiles)
+	assert.False(t, ok, "non-string value must not be reported as string")
+
+	_, ok = p.GetString(KeyPreSharedKey)
+	assert.False(t, ok, "empty string treated as unset")
+
+	_, ok = p.GetString("nonexistent")
+	assert.False(t, ok)
+}
+
+func TestPolicy_GetBool(t *testing.T) {
+	cases := []struct {
+		name string
+		raw  any
+		want bool
+		ok   bool
+	}{
+		{"native true", true, true, true},
+		{"native false", false, false, true},
+		{"string true", "true", true, true},
+		{"string false", "false", false, true},
+		{"string 1", "1", true, true},
+		{"string 0", "0", false, true},
+		{"string yes", "yes", true, true},
+		{"string no", "no", false, true},
+		{"int nonzero", 1, true, true},
+		{"int zero", 0, false, true},
+		{"int64 nonzero", int64(2), true, true},
+		{"int64 zero", int64(0), false, true},
+		{"string garbage", "maybe", false, false},
+		{"float unsupported", 1.0, false, false},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			p := NewPolicy(map[string]any{KeyDisableProfiles: c.raw})
+			got, ok := p.GetBool(KeyDisableProfiles)
+			assert.Equal(t, c.ok, ok)
+			if c.ok {
+				assert.Equal(t, c.want, got)
+			}
+		})
+	}
+
+	_, ok := NewPolicy(nil).GetBool(KeyDisableProfiles)
+	assert.False(t, ok)
+}
+
+func TestPolicy_GetStringSlice(t *testing.T) {
+	t.Run("native string slice", func(t *testing.T) {
+		p := NewPolicy(map[string]any{
+			KeySplitTunnelApps: []string{"com.a", "com.b"},
+		})
+		got, ok := p.GetStringSlice(KeySplitTunnelApps)
+		assert.True(t, ok)
+		assert.Equal(t, []string{"com.a", "com.b"}, got)
+	})
+
+	t.Run("any slice of strings", func(t *testing.T) {
+		p := NewPolicy(map[string]any{
+			KeySplitTunnelApps: []any{"com.a", "com.b"},
+		})
+		got, ok := p.GetStringSlice(KeySplitTunnelApps)
+		assert.True(t, ok)
+		assert.Equal(t, []string{"com.a", "com.b"}, got)
+	})
+
+	t.Run("single string lifts to one-element slice", func(t *testing.T) {
+		p := NewPolicy(map[string]any{
+			KeySplitTunnelApps: "com.a",
+		})
+		got, ok := p.GetStringSlice(KeySplitTunnelApps)
+		assert.True(t, ok)
+		assert.Equal(t, []string{"com.a"}, got)
+	})
+
+	t.Run("mixed any slice rejected", func(t *testing.T) {
+		p := NewPolicy(map[string]any{
+			KeySplitTunnelApps: []any{"com.a", 1},
+		})
+		_, ok := p.GetStringSlice(KeySplitTunnelApps)
+		assert.False(t, ok)
+	})
+
+	t.Run("missing key", func(t *testing.T) {
+		p := NewPolicy(nil)
+		_, ok := p.GetStringSlice(KeySplitTunnelApps)
+		assert.False(t, ok)
+	})
+}
+
+func TestLoadPolicy_PlatformStubReturnsEmpty(t *testing.T) {
+	// loadPlatformPolicy is a stub on every OS for Phase 1. LoadPolicy must
+	// degrade gracefully and never return nil.
+	p := LoadPolicy()
+	require.NotNil(t, p)
+	assert.True(t, p.IsEmpty())
+	assert.Empty(t, p.ManagedKeys())
+}

client/mdm/policy_windows.go

@@ -0,0 +1,108 @@
+//go:build windows
+
+package mdm
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows/registry"
+)
+
+// policyRegistryPath is the well-known MDM policy registry key for NetBird.
+// Admins push values here through Group Policy, Intune ADMX ingestion, an
+// Intune custom Registry CSP profile, or `reg add` during MSI deployment.
+// Listed in the project's docs/mdm/netbird.admx schema.
+const policyRegistryPath = `Software\Policies\NetBird`
+
+// readRegistryValue reads a single value under policyRegistryPath and,
+// on success, stores the type-coerced result in out[canonical]. Type
+// coercion mirrors loadPlatformPolicy's documented mapping:
+//   - REG_SZ / REG_EXPAND_SZ -> string (REG_EXPAND_SZ is expanded by the API)
+//   - REG_DWORD / REG_QWORD  -> int64
+//   - REG_MULTI_SZ           -> []string
+//
+// Unsupported value types and per-value read failures are logged at
+// warn level and skipped — one malformed value must not block the
+// surrounding loop. Extracted from loadPlatformPolicy to keep that
+// function's cognitive complexity in check.
+func readRegistryValue(k registry.Key, name, canonical string, out map[string]any) {
+	_, valType, err := k.GetValue(name, nil)
+	if err != nil {
+		log.Warnf("MDM stat %s\\%s: %v", policyRegistryPath, name, err)
+		return
+	}
+	switch valType {
+	case registry.SZ, registry.EXPAND_SZ:
+		if v, _, err := k.GetStringValue(name); err == nil {
+			out[canonical] = v
+		} else {
+			log.Warnf("MDM read string %s\\%s: %v", policyRegistryPath, name, err)
+		}
+	case registry.DWORD, registry.QWORD:
+		if v, _, err := k.GetIntegerValue(name); err == nil {
+			// uint64 from the registry API; Policy.GetBool / GetInt
+			// helpers consume int64, so narrow safely.
+			out[canonical] = int64(v)
+		} else {
+			log.Warnf("MDM read int %s\\%s: %v", policyRegistryPath, name, err)
+		}
+	case registry.MULTI_SZ:
+		if v, _, err := k.GetStringsValue(name); err == nil {
+			out[canonical] = v
+		} else {
+			log.Warnf("MDM read multi-string %s\\%s: %v", policyRegistryPath, name, err)
+		}
+	default:
+		log.Warnf("MDM ignoring unsupported registry value type %d at %s\\%s",
+			valType, policyRegistryPath, name)
+	}
+}
+
+// loadPlatformPolicy reads the MDM-managed configuration from the
+// Windows registry under HKLM\Software\Policies\NetBird. Returns:
+//   - (nil, nil)  when the key is absent (device not MDM-enrolled for NetBird)
+//   - (map, nil)  with N entries when N managed values are set (N may be 0)
+//   - (nil, err)  on open / enumerate registry errors
+//
+// Per-value type coercion + skip-on-error is delegated to
+// readRegistryValue. Unknown value names are logged and skipped so a
+// malformed deployment does not block startup.
+func loadPlatformPolicy() (map[string]any, error) {
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, policyRegistryPath, registry.QUERY_VALUE)
+	if err != nil {
+		if errors.Is(err, registry.ErrNotExist) {
+			// Not enrolled. Caller treats nil as "no MDM source present".
+			//nolint:nilnil // (nil, nil) is the documented platform-absent sentinel; see LoadPolicy.
+			return nil, nil
+		}
+		return nil, fmt.Errorf("open %s: %w", policyRegistryPath, err)
+	}
+	defer func() {
+		if closeErr := k.Close(); closeErr != nil {
+			log.Warnf("MDM close registry key %s: %v", policyRegistryPath, closeErr)
+		}
+	}()
+
+	names, err := k.ReadValueNames(-1)
+	if err != nil {
+		return nil, fmt.Errorf("enumerate values of %s: %w", policyRegistryPath, err)
+	}
+
+	out := make(map[string]any, len(names))
+	for _, name := range names {
+		// Canonicalize the registry value name against the known MDM key
+		// set so Policy.HasKey lookups (which use the canonical names)
+		// succeed regardless of the casing used by the admin's ADMX or
+		// `reg add` command.
+		canonical, known := canonicalKey[strings.ToLower(name)]
+		if !known {
+			log.Warnf("MDM ignoring unknown registry value %s\\%s", policyRegistryPath, name)
+			continue
+		}
+		readRegistryValue(k, name, canonical, out)
+	}
+	return out, nil
+}

client/mdm/ticker.go

@@ -0,0 +1,129 @@
+package mdm
+
+import (
+	"context"
+	"reflect"
+	"sort"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// DefaultReloadInterval is the production cadence at which the desktop daemon
+// re-reads the OS-native MDM policy. Picked to balance responsiveness against
+// registry/plist I/O overhead. Mobile builds use OS-side notifications
+// instead, hence anticipating the ticker mechanism entirely.
+const DefaultReloadInterval = 1 * time.Minute
+
+// policyLoader is the indirection through which the ticker reads the
+// OS-native policy, both for the initial observation and on every tick.
+// Production points it at LoadPolicy; tests in this package override it to
+// feed a scripted sequence of policies without touching the real OS store.
+var policyLoader = LoadPolicy
+
+// Ticker periodically re-reads the OS-native MDM policy via LoadPolicy and
+// invokes the onChange callback (supplied to Run) whenever the observed
+// Policy diverges from the last observation (added / removed / changed
+// keys). Launch with Run from a goroutine; cancel the supplied context
+// to stop.
+type Ticker struct {
+	interval time.Duration
+	prev     *Policy
+}
+
+// NewTicker constructs a Ticker that will re-read the OS-native policy
+// every reloadInterval once Run is called.
+// The initial snapshot is populated by calling policyLoader at
+// construction time so the first tick only fires
+// onChange when the policy actually changed since boot — without
+// this baseline the first tick would report every currently-managed
+// key as "added" and trigger a spurious engine restart.
+func NewTicker(reloadInterval time.Duration) *Ticker {
+	return &Ticker{
+		interval: reloadInterval,
+		prev:     policyLoader(),
+	}
+}
+
+// Run blocks until ctx is cancelled, polling the OS-native policy store at
+// the configured cadence and emitting log lines + onChange callback on
+// every observed diff. onChange must be non-nil.
+func (t *Ticker) Run(ctx context.Context, onChange func(prev, curr *Policy) error) {
+	tk := time.NewTicker(t.interval)
+	defer tk.Stop()
+	log.Infof("MDM policy reload ticker started (interval=%s)", t.interval)
+	for {
+		select {
+		case <-ctx.Done():
+			log.Info("MDM policy reload ticker stopped")
+			return
+		case <-tk.C:
+			curr := policyLoader()
+			if policiesEqual(t.prev, curr) {
+				continue
+			}
+			added, removed, changed := diffPolicies(t.prev, curr)
+			log.Infof("MDM policy changed: added=%v removed=%v changed=%v",
+				added, removed, changed)
+			prev := t.prev
+			if err := onChange(prev, curr); err != nil {
+				log.Errorf("MDM policy change handler failed (retrying in 1 minute): %v", err)
+				continue
+			}
+			t.prev = curr
+		}
+	}
+}
+
+// policiesEqual reports whether two Policy instances carry the same
+// managed key set with identical values. Nil and empty policies
+// compare equal; one-nil/one-non-empty compare not equal; otherwise
+// the underlying values maps are compared with reflect.DeepEqual.
+func policiesEqual(a, b *Policy) bool {
+	if a.IsEmpty() && b.IsEmpty() {
+		return true
+	}
+	if a == nil || b == nil {
+		return false
+	}
+	return reflect.DeepEqual(a.values, b.values)
+}
+
+// diffPolicies returns the keys added in curr, removed from prev, and
+// whose values changed between prev and curr. Each slice is sorted
+// lexicographically for stable log output; value differences are
+// determined with reflect.DeepEqual.
+func diffPolicies(prev, curr *Policy) (added, removed, changed []string) {
+	prevKVs := mapOf(prev)
+	currKVs := mapOf(curr)
+	for k := range currKVs {
+		if _, ok := prevKVs[k]; !ok {
+			added = append(added, k)
+		} else if !reflect.DeepEqual(prevKVs[k], currKVs[k]) {
+			changed = append(changed, k)
+		}
+	}
+	for k := range prevKVs {
+		if _, ok := currKVs[k]; !ok {
+			removed = append(removed, k)
+		}
+	}
+	sort.Strings(added)
+	sort.Strings(removed)
+	sort.Strings(changed)
+	return added, removed, changed
+}
+
+// mapOf returns a (possibly empty, never nil) copy of the underlying
+// values map of a Policy so callers outside this package can compare
+// keys/values across the type boundary. Returns an empty map on nil p.
+func mapOf(p *Policy) map[string]any {
+	if p == nil {
+		return map[string]any{}
+	}
+	out := make(map[string]any, len(p.values))
+	for k, v := range p.values {
+		out[k] = v
+	}
+	return out
+}

client/mdm/ticker_test.go

@@ -0,0 +1,100 @@
+package mdm
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// testReloadInterval for speeding up the ticker cadence under `go test`
+const testReloadInterval = 1 * time.Second
+
+// withPolicyLoader overrides the package-level policyLoader for the duration
+// of the test so the ticker observes a scripted policy instead of the real
+// OS-native store. The original loader is restored on cleanup.
+func withPolicyLoader(t *testing.T, fn func() *Policy) {
+	t.Helper()
+	prev := policyLoader
+	policyLoader = fn
+	t.Cleanup(func() { policyLoader = prev })
+}
+
+func TestTicker_FiresOnChangeWithDelta(t *testing.T) {
+	var mu sync.Mutex
+	current := NewPolicy(nil) // initial observation: empty (no enforcement)
+	withPolicyLoader(t, func() *Policy {
+		mu.Lock()
+		defer mu.Unlock()
+		return current
+	})
+
+	type change struct{ prev, curr *Policy }
+	changes := make(chan change, 1)
+	tk := NewTicker(testReloadInterval)
+	require.Equal(t, testReloadInterval, tk.interval)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() {
+		tk.Run(ctx, func(prev, curr *Policy) error {
+			select {
+			case changes <- change{prev, curr}:
+			default:
+			}
+			return nil
+		})
+		close(done)
+	}()
+	// Stop Run and wait for it to exit before returning, so the policyLoader
+	// restore in t.Cleanup can't race the ticker goroutine still reading it.
+	defer func() { cancel(); <-done }()
+
+	// Flip the OS-observed policy from empty to one managed key. The next
+	// tick must detect the diff and invoke onChange.
+	mu.Lock()
+	current = NewPolicy(map[string]any{KeyManagementURL: "https://mdm.example.com:443"})
+	mu.Unlock()
+
+	select {
+	case c := <-changes:
+		assert.True(t, c.prev.IsEmpty(), "prev should be the initial empty policy")
+		assert.True(t, c.curr.HasKey(KeyManagementURL), "curr should carry the newly-pushed managed key")
+	case <-time.After(5 * time.Second):
+		t.Fatal("onChange not invoked within 5s; ticker should fire every 1s under test")
+	}
+}
+
+func TestTicker_NoCallbackWhenPolicyUnchanged(t *testing.T) {
+	withPolicyLoader(t, func() *Policy {
+		return NewPolicy(map[string]any{KeyBlockInbound: true})
+	})
+
+	fired := make(chan struct{}, 1)
+	tk := NewTicker(testReloadInterval)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() {
+		tk.Run(ctx, func(_, _ *Policy) error {
+			select {
+			case fired <- struct{}{}:
+			default:
+			}
+			return nil
+		})
+		close(done)
+	}()
+	defer func() { cancel(); <-done }()
+
+	// Over ~2 ticks at the 1s test cadence the policy never changes, so the
+	// diff guard must suppress the callback entirely.
+	select {
+	case <-fired:
+		t.Fatal("onChange fired despite an unchanged policy")
+	case <-time.After(2500 * time.Millisecond):
+	}
+}