[management] Add SSO session extend flow (management) (#6197)

* add SSO session extend flow (management)

Adds the management-server half of the SSO session-extension feature:

- New ExtendAuthSession gRPC RPC that refreshes a peer's session expiry
  using a fresh JWT, validated through the same pipeline as Login but
  without tearing down the tunnel or redoing the NetworkMap sync.
- Per-peer SessionExpiresAt timestamp on every LoginResponse and
  SyncResponse so connected clients learn the deadline on the existing
  long-lived stream, and admin-side changes (toggling expiration,
  changing the expiration window) reach every peer within seconds.
- SessionExpiresAt(...) helper on Peer that derives the absolute UTC
  deadline from LastLogin + the account-level PeerLoginExpiration
  setting, returning zero when the peer is not SSO-tracked or expiration
  is disabled.

The matching client-side consumer of these fields lands separately.

* encode SessionExpiresAt as 3-state on the wire

Previously the `sessionExpiresAt` field on LoginResponse, SyncResponse
and ExtendAuthSessionResponse was 2-state: a valid timestamp meant
"new deadline", and nil meant "clear". That conflated two distinct
meanings — "no info in this snapshot" vs "expiry is explicitly off /
peer is not SSO-tracked" — so a Sync push that legitimately couldn't
compute the deadline (settings lookup failed) would silently clear the
client's anchor and lose the warning window.

Three states now, encoded on the same field number (no .proto schema
churn — only comments and the server-side encoder change):

  - nil pointer (field absent) → "no info"; client preserves anchor
  - &Timestamp{} (seconds=0, nanos=0) → explicit "disabled / not SSO"
    sentinel; client clears
  - valid timestamp → new absolute UTC deadline

A new encodeSessionExpiresAt helper centralises the zero/non-zero
encoding and is shared by the Sync, Login and ExtendAuthSession
builders. The Sync builder still emits nil when settings are missing.
Login and ExtendAuthSession always carry an authoritative value.

The matching client-side decoder lands on feature/session-extend.

* add UserExtendedPeerSession activity event

ExtendAuthSession previously reused UserLoggedInPeer for its audit
record, which conflated two distinct user actions: a full interactive
SSO login (tunnel re-established, network map resync) versus an
in-place deadline refresh (tunnel untouched). Auditors reading the log
couldn't tell which one happened, and downstream dashboards/alerts on
"login" volume were polluted by routine extends.

Adds a dedicated UserExtendedPeerSession Activity (code 125,
"user.peer.session.extend") and switches ExtendPeerSession over to it.
The peer-extend audit trail is now distinguishable from interactive
logins.

* make ExtendAuthSession JWT-retry backoff cancellable

Skip the retry log and 200ms wait on the final attempt, and replace the
uncancellable time.Sleep with a select on time.After/ctx.Done so an
upstream cancellation aborts the wait instead of running it to
completion.

management/server/account.go

@@ -355,7 +355,17 @@ func (am *DefaultAccountManager) UpdateAccountSettings(ctx context.Context, acco
 			oldSettings.LazyConnectionEnabled != newSettings.LazyConnectionEnabled ||
 			oldSettings.DNSDomain != newSettings.DNSDomain ||
 			oldSettings.AutoUpdateVersion != newSettings.AutoUpdateVersion ||
-			oldSettings.AutoUpdateAlways != newSettings.AutoUpdateAlways {
+			oldSettings.AutoUpdateAlways != newSettings.AutoUpdateAlways ||
+			oldSettings.PeerLoginExpirationEnabled != newSettings.PeerLoginExpirationEnabled ||
+			oldSettings.PeerLoginExpiration != newSettings.PeerLoginExpiration {
+			// Session deadline is derived from LastLogin + PeerLoginExpiration
+			// on every Login/Sync response. Without a fan-out push, connected
+			// peers keep the deadline they received at login time and only see
+			// the new value after the next unrelated NetworkMap change. Add
+			// these two fields to the trigger list so admin-side expiry tweaks
+			// (e.g. shortening from 24h to 1h) reach every connected peer
+			// within seconds, which is what the proactive-warning feature
+			// relies on (see client/internal/auth/sessionwatch).
 			updateAccountPeers = true
 		}
 

management/server/account/manager.go

@@ -109,6 +109,7 @@ type Manager interface {
 	UpdateAccountSettings(ctx context.Context, accountID, userID string, newSettings *types.Settings) (*types.Settings, error)
 	UpdateAccountOnboarding(ctx context.Context, accountID, userID string, newOnboarding *types.AccountOnboarding) (*types.AccountOnboarding, error)
 	LoginPeer(ctx context.Context, login types.PeerLogin) (*nbpeer.Peer, *types.NetworkMap, []*posture.Checks, error)                       // used by peer gRPC API
+	ExtendPeerSession(ctx context.Context, peerPubKey, userID string) (time.Time, error)                                                   // used by peer gRPC API for ExtendAuthSession
 	SyncPeer(ctx context.Context, sync types.PeerSync, accountID string) (*nbpeer.Peer, *types.NetworkMap, []*posture.Checks, int64, error) // used by peer gRPC API
 	GetExternalCacheManager() ExternalCacheManager
 	GetPostureChecks(ctx context.Context, accountID, postureChecksID, userID string) (*posture.Checks, error)

management/server/account/manager_mock.go

@@ -1304,6 +1304,21 @@ func (mr *MockManagerMockRecorder) LoginPeer(ctx, login interface{}) *gomock.Cal
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LoginPeer", reflect.TypeOf((*MockManager)(nil).LoginPeer), ctx, login)
 }
 
+// ExtendPeerSession mocks base method.
+func (m *MockManager) ExtendPeerSession(ctx context.Context, peerPubKey, userID string) (time.Time, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ExtendPeerSession", ctx, peerPubKey, userID)
+	ret0, _ := ret[0].(time.Time)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// ExtendPeerSession indicates an expected call of ExtendPeerSession.
+func (mr *MockManagerMockRecorder) ExtendPeerSession(ctx, peerPubKey, userID interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ExtendPeerSession", reflect.TypeOf((*MockManager)(nil).ExtendPeerSession), ctx, peerPubKey, userID)
+}
+
 // MarkPeerConnected mocks base method.
 func (m *MockManager) MarkPeerConnected(ctx context.Context, peerKey string, realIP net.IP, accountID string, sessionStartedAt int64) error {
 	m.ctrl.T.Helper()

management/server/activity/codes.go

@@ -240,6 +240,10 @@ const (
 	AccountLocalMfaEnabled Activity = 123
 	// AccountLocalMfaDisabled indicates that a user disabled TOTP MFA for local users
 	AccountLocalMfaDisabled Activity = 124
+	// UserExtendedPeerSession indicates that a user refreshed their peer's
+	// SSO session deadline via ExtendAuthSession without re-establishing the
+	// tunnel. Distinct from UserLoggedInPeer (full interactive login).
+	UserExtendedPeerSession Activity = 125
 
 	AccountDeleted Activity = 99999
 )
@@ -394,6 +398,8 @@ var activityMap = map[Activity]Code{
 	AccountLocalMfaEnabled:  {"Account local MFA enabled", "account.setting.local.mfa.enable"},
 	AccountLocalMfaDisabled: {"Account local MFA disabled", "account.setting.local.mfa.disable"},
 
+	UserExtendedPeerSession: {"User extended peer session", "user.peer.session.extend"},
+
 	DomainAdded:     {"Domain added", "domain.add"},
 	DomainDeleted:   {"Domain deleted", "domain.delete"},
 	DomainValidated: {"Domain validated", "domain.validate"},

management/server/mock_server/account_mock.go

@@ -98,6 +98,7 @@ type MockAccountManager struct {
 	GetPeerFunc                           func(ctx context.Context, accountID, peerID, userID string) (*nbpeer.Peer, error)
 	UpdateAccountSettingsFunc             func(ctx context.Context, accountID, userID string, newSettings *types.Settings) (*types.Settings, error)
 	LoginPeerFunc                         func(ctx context.Context, login types.PeerLogin) (*nbpeer.Peer, *types.NetworkMap, []*posture.Checks, error)
+	ExtendPeerSessionFunc                 func(ctx context.Context, peerPubKey, userID string) (time.Time, error)
 	SyncPeerFunc                          func(ctx context.Context, sync types.PeerSync, accountID string) (*nbpeer.Peer, *types.NetworkMap, []*posture.Checks, int64, error)
 	InviteUserFunc                        func(ctx context.Context, accountID string, initiatorUserID string, targetUserEmail string) error
 	ApproveUserFunc                       func(ctx context.Context, accountID, initiatorUserID, targetUserID string) (*types.UserInfo, error)
@@ -860,6 +861,14 @@ func (am *MockAccountManager) LoginPeer(ctx context.Context, login types.PeerLog
 	return nil, nil, nil, status.Errorf(codes.Unimplemented, "method LoginPeer is not implemented")
 }
 
+// ExtendPeerSession mocks ExtendPeerSession of the AccountManager interface
+func (am *MockAccountManager) ExtendPeerSession(ctx context.Context, peerPubKey, userID string) (time.Time, error) {
+	if am.ExtendPeerSessionFunc != nil {
+		return am.ExtendPeerSessionFunc(ctx, peerPubKey, userID)
+	}
+	return time.Time{}, status.Errorf(codes.Unimplemented, "method ExtendPeerSession is not implemented")
+}
+
 // SyncPeer mocks SyncPeer of the AccountManager interface
 func (am *MockAccountManager) SyncPeer(ctx context.Context, sync types.PeerSync, accountID string) (*nbpeer.Peer, *types.NetworkMap, []*posture.Checks, int64, error) {
 	if am.SyncPeerFunc != nil {

management/server/peer.go

@@ -1151,6 +1151,79 @@ func (am *DefaultAccountManager) LoginPeer(ctx context.Context, login types.Peer
 	return p, nmap, pc, err
 }
 
+// ExtendPeerSession refreshes the peer's SSO session deadline by updating
+// LastLogin after a successful JWT validation. The tunnel is untouched: no
+// network map sync, no peer reconnect.
+//
+// Preconditions enforced here:
+//   - userID must be present (caller validated the JWT and extracted the user ID).
+//   - The peer must exist and be SSO-registered (AddedWithSSOLogin) with
+//     LoginExpirationEnabled.
+//   - Account-level PeerLoginExpirationEnabled must be true.
+//   - The JWT user must match peer.UserID (mirrors LoginPeer at peer.go ~1028).
+//
+// Returns the new absolute UTC deadline.
+func (am *DefaultAccountManager) ExtendPeerSession(ctx context.Context, peerPubKey, userID string) (time.Time, error) {
+	if userID == "" {
+		return time.Time{}, status.Errorf(status.PermissionDenied, "session extend requires a JWT")
+	}
+
+	accountID, err := am.Store.GetAccountIDByPeerPubKey(ctx, peerPubKey)
+	if err != nil {
+		return time.Time{}, err
+	}
+
+	settings, err := am.Store.GetAccountSettings(ctx, store.LockingStrengthNone, accountID)
+	if err != nil {
+		return time.Time{}, err
+	}
+	if !settings.PeerLoginExpirationEnabled {
+		return time.Time{}, status.Errorf(status.PreconditionFailed, "peer login expiration is disabled for the account")
+	}
+
+	var refreshed *nbpeer.Peer
+	err = am.Store.ExecuteInTransaction(ctx, func(transaction store.Store) error {
+		peer, err := transaction.GetPeerByPeerPubKey(ctx, store.LockingStrengthUpdate, peerPubKey)
+		if err != nil {
+			return err
+		}
+
+		if !peer.AddedWithSSOLogin() || !peer.LoginExpirationEnabled {
+			return status.Errorf(status.PreconditionFailed, "peer is not eligible for session extension")
+		}
+
+		if peer.UserID != userID {
+			log.WithContext(ctx).Warnf("user mismatch when extending session for peer %s: peer user %s, jwt user %s", peer.ID, peer.UserID, userID)
+			return status.NewPeerLoginMismatchError()
+		}
+
+		peer = peer.UpdateLastLogin()
+		if err := transaction.SavePeer(ctx, accountID, peer); err != nil {
+			return err
+		}
+
+		if err := transaction.SaveUserLastLogin(ctx, accountID, userID, peer.GetLastLogin()); err != nil {
+			log.WithContext(ctx).Debugf("failed to update user last login during session extend: %v", err)
+		}
+
+		am.StoreEvent(ctx, userID, peer.ID, accountID, activity.UserExtendedPeerSession, peer.EventMeta(am.networkMapController.GetDNSDomain(settings)))
+		refreshed = peer
+		return nil
+	})
+	if err != nil {
+		return time.Time{}, err
+	}
+
+	// Reschedule the per-account expiration job. schedulePeerLoginExpiration
+	// is a no-op when a job is already running, but the running job will pick
+	// up the new LastLogin on its next tick. Calling it here is harmless and
+	// guarantees a job is in flight even if a prior one ended right before
+	// the extend.
+	am.schedulePeerLoginExpiration(ctx, accountID)
+
+	return refreshed.SessionExpiresAt(settings.PeerLoginExpirationEnabled, settings.PeerLoginExpiration), nil
+}
+
 // getPeerPostureChecks returns the posture checks for the peer.
 func getPeerPostureChecks(ctx context.Context, transaction store.Store, accountID, peerID string) ([]*posture.Checks, error) {
 	policies, err := transaction.GetAccountPolicies(ctx, store.LockingStrengthNone, accountID)

management/server/peer/peer.go

@@ -367,6 +367,22 @@ func (p *Peer) LoginExpired(expiresIn time.Duration) (bool, time.Duration) {
 	return timeLeft <= 0, timeLeft
 }
 
+// SessionExpiresAt returns the absolute UTC instant at which the peer's SSO
+// session expires, derived from LastLogin and the account-level
+// PeerLoginExpiration setting. Returns the zero value when login expiration
+// does not apply (peer not SSO-registered, peer-level toggle off, or account
+// expiry disabled). Callers should treat the zero value as "no deadline".
+func (p *Peer) SessionExpiresAt(accountExpirationEnabled bool, expiresIn time.Duration) time.Time {
+	if !accountExpirationEnabled || !p.AddedWithSSOLogin() || !p.LoginExpirationEnabled {
+		return time.Time{}
+	}
+	last := p.GetLastLogin()
+	if last.IsZero() {
+		return time.Time{}
+	}
+	return last.Add(expiresIn).UTC()
+}
+
 // FQDN returns peers FQDN combined of the peer's DNS label and the system's DNS domain
 func (p *Peer) FQDN(dnsDomain string) string {
 	if dnsDomain == "" {