[client] iOS SSH: gate JWT behind server detection, reuse jwtcache (#6759)

* feat(ios/ssh): add ConnectNetBirdPeer, JWT cache, and WireGuard dialer

- Add ConnectNetBirdPeer() method that skips banner detection and
  authenticates directly via JWT (mirrors NetBird web dashboard flow)
- Cache JWT token for 8 minutes to avoid OAuth re-auth on every reconnect
  (SSH servers reject tokens older than DefaultJWTMaxTokenAge = 10 min)
- Bind SSH sockets to the WireGuard interface via IP_BOUND_IF (Darwin
  syscall 25) so connections to 100.x.x.x peers route through the tunnel
  in the iOS Network Extension process
- Improve auth failure error message with actionable checklist
- Add base64 JWT claims debug logging for auth troubleshooting

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(ios/ssh): never offer the JWT to an unverified SSH service

Remove ConnectNetBirdPeer. It skipped banner detection and sent the JWT
as a password to whatever sshd answered, under InsecureIgnoreHostKey.
WireGuard authenticates the peer machine, not the SSH service listening
on it, so that handed a valid bearer token to an unidentified listener —
a plain OpenSSH + PAM setup may even log the password attempt.

Connect is now the only entry point. Detection is what proves the
listener is a NetBird SSH service before the token is offered, and the
JWT path already verifies the host key against the management-plane
registry via engineHostKeyVerifier. A peer whose NetBird SSH is disabled
is served by plain sshd and authenticates by key or password like any
other host, so it stays reachable without an OAuth round trip.

Move the NetBird-specific auth-failure checklist into annotateAuthError,
gated on serverType.RequiresJWT(), so a regular sshd rejection no longer
tells the user to check dashboard SSH access. Drop base64DecodeJWT,
which was left unused.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

client/ios/NetBirdSDK/client.go

@@ -21,6 +21,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
+	"github.com/netbirdio/netbird/client/ssh/jwtcache"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/formatter"
 	"github.com/netbirdio/netbird/route"
@@ -84,7 +85,14 @@ type Client struct {
 
 	stateMu       sync.RWMutex
 	connectClient *internal.ConnectClient
-	config        *profilemanager.Config
+	// config holds the active configuration once Run has loaded it. Consumed by
+	// the in-app SSH client for the NetBird SSH key and the OAuth flow.
+	config *profilemanager.Config
+
+	// sshJWTCache keeps the SSH JWT token between reconnects so the user is not
+	// forced through the browser OAuth flow on every session. Lives on Client
+	// (not SSHClient) because the app creates a new SSHClient per session.
+	sshJWTCache *jwtcache.Cache
 }
 
 // NewClient instantiate a new Client
@@ -101,6 +109,7 @@ func NewClient(cfgFile, stateFile, cacheDir, logFilePath, deviceName string, osV
 		ctxCancelLock:         &sync.Mutex{},
 		networkChangeListener: networkChangeListener,
 		dnsManager:            dnsManager,
+		sshJWTCache:           jwtcache.New(),
 	}
 }
 
@@ -175,6 +184,7 @@ func (c *Client) Run(fd int32, interfaceName string, envList *EnvList) error {
 	ctx = internal.CtxInitState(ctx)
 	c.onHostDnsFn = func([]string) {}
 	cfg.WgIface = interfaceName
+	c.config = cfg
 
 	connectClient := internal.NewConnectClient(ctx, cfg, c.recorder)
 	c.setState(cfg, connectClient)
@@ -697,6 +707,13 @@ func (c *Client) stateSnapshot() (*profilemanager.Config, *internal.ConnectClien
 	return c.config, c.connectClient
 }
 
+// sshState returns the active config and the running connect client for the
+// in-app SSH client. Both are nil until Run has loaded the config and started
+// the tunnel.
+func (c *Client) sshState() (*profilemanager.Config, *internal.ConnectClient) {
+	return c.stateSnapshot()
+}
+
 func formatDuration(d time.Duration) string {
 	ds := d.String()
 	dotIndex := strings.Index(ds, ".")

client/ios/NetBirdSDK/ssh_client.go

@@ -0,0 +1,512 @@
+//go:build ios
+
+package NetBirdSDK
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	gossh "golang.org/x/crypto/ssh"
+
+	"github.com/netbirdio/netbird/client/internal"
+	"github.com/netbirdio/netbird/client/internal/auth"
+	"github.com/netbirdio/netbird/client/internal/profilemanager"
+	nbssh "github.com/netbirdio/netbird/client/ssh"
+	"github.com/netbirdio/netbird/client/ssh/detection"
+	"github.com/netbirdio/netbird/client/ssh/jwtcache"
+)
+
+const (
+	sshDialTimeout      = 30 * time.Second
+	sshDetectionTimeout = 5 * time.Second
+)
+
+// SSHTerminalListener receives SSH session events. It is implemented in Swift.
+//
+// All callbacks are invoked from goroutines and may run concurrently with each
+// other; the implementation must be safe to call from any thread.
+type SSHTerminalListener interface {
+	OnConnected()
+	OnData(data []byte)
+	OnClose(reason string)
+	OnError(message string)
+}
+
+// SSHClient is a NetBird-aware SSH client exposed to Swift via gomobile.
+//
+// It dials through the running NetBird tunnel and runs a standard SSH session
+// on top with PTY enabled. Host-key verification uses the NetBird-provided
+// peer SSH host keys, identical to the desktop client.
+type SSHClient struct {
+	nb        *Client
+	mu        sync.Mutex
+	listener  SSHTerminalListener
+	urlOpener URLOpener
+
+	sshClient *gossh.Client
+	session   *gossh.Session
+	stdin     io.WriteCloser
+	closed    bool
+}
+
+// NewSSHClient creates a new SSH client bound to the running NetBird Client.
+func NewSSHClient(c *Client) *SSHClient {
+	return &SSHClient{nb: c}
+}
+
+// SetListener registers the Swift listener. Must be called before Connect to
+// receive any events.
+func (s *SSHClient) SetListener(l SSHTerminalListener) {
+	s.mu.Lock()
+	s.listener = l
+	s.mu.Unlock()
+}
+
+// SetURLOpener registers the Swift URL opener used to display the device-code
+// authorization page in an in-app browser when the target peer requires JWT
+// authentication. Must be set before Connect to be effective.
+func (s *SSHClient) SetURLOpener(opener URLOpener) {
+	s.mu.Lock()
+	s.urlOpener = opener
+	s.mu.Unlock()
+}
+
+// Connect dials the SSH server through the NetBird tunnel and performs the
+// SSH handshake. It auto-detects the server type via SSH banner inspection
+// and selects the appropriate authentication path:
+//
+//   - NetBird-SSH server requiring JWT: launches the OAuth 2.0 device-code
+//     flow, opens the verification URL through the registered URLOpener, and
+//     uses the resulting token as the SSH password. Host-key verification
+//     uses the NetBird peer registry.
+//   - NetBird-SSH server without JWT: authenticates with the NetBird SSH
+//     private key. Host-key verification uses the NetBird peer registry.
+//   - Regular SSH server (e.g. OpenSSH): authenticates with the NetBird key
+//     first (so a user-installed NetBird public key works), then falls back
+//     to the supplied password if non-empty. Host-key verification is
+//     disabled (TOFU pending).
+//
+// The password parameter is only consulted for regular SSH servers.
+//
+// This is the only way to open a session, deliberately so: the JWT is a bearer
+// token, and detection is what proves the listener is a NetBird SSH service
+// before the token is offered to it. A peer whose NetBird SSH is disabled is
+// served by plain sshd and authenticates by key or password like any other
+// host, so it stays reachable without an OAuth round trip.
+func (s *SSHClient) Connect(host string, port int, user, password string) error {
+	cfg, cc := s.nb.sshState()
+	if cc == nil {
+		return errors.New("netbird client not running")
+	}
+	if cfg == nil {
+		return errors.New("netbird config not loaded")
+	}
+	engine := cc.Engine()
+	if engine == nil {
+		return errors.New("netbird engine not available")
+	}
+
+	wgDialer := makeWGDialer(cfg.WgIface, sshDialTimeout)
+
+	serverType := detectServerType(host, port, wgDialer)
+	log.Infof("SSH server type for %s:%d: %s", host, port, serverType)
+
+	authMethods, hostKeyCallback, err := s.buildAuth(cfg, engine, serverType, password)
+	if err != nil {
+		return err
+	}
+
+	clientConfig := &gossh.ClientConfig{
+		User:            user,
+		Auth:            authMethods,
+		HostKeyCallback: hostKeyCallback,
+		Timeout:         sshDialTimeout,
+	}
+	if err := s.dialAndHandshake(host, port, clientConfig, wgDialer); err != nil {
+		return annotateAuthError(err, serverType, user)
+	}
+	return nil
+}
+
+// annotateAuthError adds NetBird-specific guidance to an authentication
+// failure, but only for a server that detection identified as NetBird-SSH.
+// There a rejection nearly always means the peer's dashboard SSH access is not
+// configured for this account, which the raw gossh error does not convey.
+func annotateAuthError(err error, serverType detection.ServerType, user string) error {
+	if !serverType.RequiresJWT() {
+		return err
+	}
+	msg := err.Error()
+	if !strings.Contains(msg, "no supported methods remain") &&
+		!strings.Contains(msg, "unable to authenticate") {
+		return err
+	}
+	return fmt.Errorf("NetBird SSH authentication rejected.\n\n"+
+		"Checklist:\n"+
+		"  1. SSH is enabled for this peer in the NetBird dashboard\n"+
+		"  2. Your account is listed under SSH access for this peer\n"+
+		"  3. The OS username (%q) is mapped to your account\n\n"+
+		"If SSH access is not configured, connect with a password instead.\n\n"+
+		"Original: %w", user, err)
+}
+
+// StartSession requests a PTY and starts an interactive shell. Output from
+// the session is forwarded to the listener via OnData.
+func (s *SSHClient) StartSession(cols, rows int) error {
+	log.Debugf("SSH: starting session %dx%d", cols, rows)
+	s.mu.Lock()
+	sshClient := s.sshClient
+	s.mu.Unlock()
+
+	if sshClient == nil {
+		return errors.New("ssh client not connected")
+	}
+
+	session, err := sshClient.NewSession()
+	if err != nil {
+		return fmt.Errorf("new session: %w", err)
+	}
+
+	modes := gossh.TerminalModes{
+		gossh.ECHO:          1,
+		gossh.TTY_OP_ISPEED: 14400,
+		gossh.TTY_OP_OSPEED: 14400,
+		gossh.VINTR:         3,
+		gossh.VQUIT:         28,
+		gossh.VERASE:        127,
+	}
+	if err := session.RequestPty("xterm-256color", rows, cols, modes); err != nil {
+		closeQuiet(session, "session after pty error")
+		return fmt.Errorf("request pty: %w", err)
+	}
+
+	stdin, err := session.StdinPipe()
+	if err != nil {
+		closeQuiet(session, "session after stdin error")
+		return fmt.Errorf("stdin pipe: %w", err)
+	}
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		closeQuiet(session, "session after stdout error")
+		return fmt.Errorf("stdout pipe: %w", err)
+	}
+	stderr, err := session.StderrPipe()
+	if err != nil {
+		closeQuiet(session, "session after stderr error")
+		return fmt.Errorf("stderr pipe: %w", err)
+	}
+
+	if err := session.Shell(); err != nil {
+		closeQuiet(session, "session after shell error")
+		return fmt.Errorf("start shell: %w", err)
+	}
+
+	s.mu.Lock()
+	s.session = session
+	s.stdin = stdin
+	s.mu.Unlock()
+
+	go s.readLoop(stdout, "stdout")
+	go s.readLoop(stderr, "stderr")
+	log.Debug("SSH: session started, shell running")
+	return nil
+}
+
+// Write sends data to the SSH session stdin.
+func (s *SSHClient) Write(data []byte) error {
+	s.mu.Lock()
+	stdin := s.stdin
+	s.mu.Unlock()
+	if stdin == nil {
+		return errors.New("ssh session not started")
+	}
+	if _, err := stdin.Write(data); err != nil {
+		return fmt.Errorf("write stdin: %w", err)
+	}
+	return nil
+}
+
+// Resize updates the PTY window size.
+func (s *SSHClient) Resize(cols, rows int) error {
+	s.mu.Lock()
+	session := s.session
+	s.mu.Unlock()
+	if session == nil {
+		return errors.New("ssh session not started")
+	}
+	return session.WindowChange(rows, cols)
+}
+
+// Close terminates the SSH session and underlying connection. Safe to call
+// multiple times.
+func (s *SSHClient) Close() error {
+	s.mu.Lock()
+	sshClient := s.sshClient
+	session := s.session
+	stdin := s.stdin
+	s.sshClient = nil
+	s.session = nil
+	s.stdin = nil
+	s.mu.Unlock()
+
+	if stdin != nil {
+		if err := stdin.Close(); err != nil {
+			log.Debugf("ssh: stdin close: %v", err)
+		}
+	}
+	if session != nil {
+		if err := session.Close(); err != nil && !errors.Is(err, io.EOF) {
+			log.Debugf("ssh: session close: %v", err)
+		}
+	}
+	var firstErr error
+	if sshClient != nil {
+		if err := sshClient.Close(); err != nil {
+			firstErr = err
+		}
+	}
+	s.notifyClose("closed by client")
+	return firstErr
+}
+
+func (s *SSHClient) buildAuth(cfg *profilemanager.Config, engine *internal.Engine,
+	serverType detection.ServerType, password string) ([]gossh.AuthMethod, gossh.HostKeyCallback, error) {
+
+	switch serverType {
+	case detection.ServerTypeNetBirdJWT:
+		token, err := s.requestJWTToken(cfg)
+		if err != nil {
+			return nil, nil, fmt.Errorf("jwt: %w", err)
+		}
+		auths := []gossh.AuthMethod{gossh.Password(token)}
+		return auths, nbssh.CreateHostKeyCallback(&engineHostKeyVerifier{engine: engine}), nil
+
+	case detection.ServerTypeNetBirdNoJWT:
+		if cfg.SSHKey == "" {
+			return nil, nil, errors.New("no NetBird SSH key available")
+		}
+		signer, err := gossh.ParsePrivateKey([]byte(cfg.SSHKey))
+		if err != nil {
+			return nil, nil, fmt.Errorf("parse netbird ssh key: %w", err)
+		}
+		auths := []gossh.AuthMethod{gossh.PublicKeys(signer)}
+		return auths, nbssh.CreateHostKeyCallback(&engineHostKeyVerifier{engine: engine}), nil
+
+	default: // regular SSH
+		var auths []gossh.AuthMethod
+		if cfg.SSHKey != "" {
+			if signer, err := gossh.ParsePrivateKey([]byte(cfg.SSHKey)); err == nil {
+				auths = append(auths, gossh.PublicKeys(signer))
+			} else {
+				log.Debugf("ssh: parse netbird key for regular auth: %v", err)
+			}
+		}
+		if password != "" {
+			pw := password
+			auths = append(auths, gossh.Password(pw))
+			auths = append(auths, gossh.KeyboardInteractive(func(_, _ string, questions []string, _ []bool) ([]string, error) {
+				answers := make([]string, len(questions))
+				for i := range questions {
+					answers[i] = pw
+				}
+				return answers, nil
+			}))
+		}
+		if len(auths) == 0 {
+			return nil, nil, errors.New("no auth method available: provide a password or configure NetBird SSH key")
+		}
+		return auths, gossh.InsecureIgnoreHostKey(), nil // nolint:gosec // TOFU not yet implemented
+	}
+}
+
+func (s *SSHClient) requestJWTToken(cfg *profilemanager.Config) (string, error) {
+	// Reuse a cached token so the user is not forced through the browser OAuth
+	// flow on every reconnect. TTL comes from cfg.SSHJWTCacheTTL, same as the
+	// daemon's cache; unset/0 disables caching.
+	if token, ok := s.nb.sshJWTCache.Get(); ok {
+		log.Debug("SSH: reusing cached JWT token")
+		return token, nil
+	}
+
+	s.mu.Lock()
+	urlOpener := s.urlOpener
+	s.mu.Unlock()
+	if urlOpener == nil {
+		return "", errors.New("URL opener not configured for JWT auth")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+
+	flow, err := auth.NewOAuthFlow(ctx, cfg, false, true, profilemanager.GetLoginHint())
+	if err != nil {
+		return "", fmt.Errorf("create oauth flow: %w", err)
+	}
+
+	flowInfo, err := flow.RequestAuthInfo(ctx)
+	if err != nil {
+		return "", fmt.Errorf("request auth info: %w", err)
+	}
+
+	go urlOpener.Open(flowInfo.VerificationURIComplete, flowInfo.UserCode)
+
+	tokenInfo, err := flow.WaitToken(ctx, flowInfo)
+	if err != nil {
+		return "", fmt.Errorf("wait for token: %w", err)
+	}
+
+	token := tokenInfo.GetTokenToUse()
+	if token == "" {
+		return "", errors.New("empty token returned by IdP")
+	}
+
+	if ttl := jwtcache.ResolveTTL(cfg.SSHJWTCacheTTL); ttl > 0 {
+		s.nb.sshJWTCache.Store(token, ttl)
+	}
+	return token, nil
+}
+
+func (s *SSHClient) dialAndHandshake(host string, port int, clientConfig *gossh.ClientConfig, dialer *net.Dialer) error {
+	addr := net.JoinHostPort(host, strconv.Itoa(port))
+	log.Infof("SSH: connecting to %s as %s", addr, clientConfig.User)
+
+	ctx, cancel := context.WithTimeout(context.Background(), sshDialTimeout)
+	defer cancel()
+
+	conn, err := dialer.DialContext(ctx, "tcp", addr)
+	if err != nil {
+		return fmt.Errorf("dial %s: %w", addr, err)
+	}
+
+	sshConn, chans, reqs, err := gossh.NewClientConn(conn, addr, clientConfig)
+	if err != nil {
+		if cerr := conn.Close(); cerr != nil {
+			log.Debugf("ssh: close after handshake error: %v", cerr)
+		}
+		return fmt.Errorf("ssh handshake: %w", err)
+	}
+
+	s.mu.Lock()
+	s.sshClient = gossh.NewClient(sshConn, chans, reqs)
+	listener := s.listener
+	s.mu.Unlock()
+
+	log.Infof("SSH: connected to %s", addr)
+	if listener != nil {
+		listener.OnConnected()
+	}
+	return nil
+}
+
+func (s *SSHClient) readLoop(r io.Reader, name string) {
+	buf := make([]byte, 4096)
+	for {
+		n, err := r.Read(buf)
+		if n > 0 {
+			s.mu.Lock()
+			listener := s.listener
+			s.mu.Unlock()
+			if listener != nil {
+				chunk := make([]byte, n)
+				copy(chunk, buf[:n])
+				listener.OnData(chunk)
+			}
+		}
+		if err != nil {
+			if !errors.Is(err, io.EOF) {
+				log.Debugf("ssh %s read: %v", name, err)
+			}
+			s.notifyClose(err.Error())
+			return
+		}
+	}
+}
+
+func (s *SSHClient) notifyClose(reason string) {
+	s.mu.Lock()
+	if s.closed {
+		s.mu.Unlock()
+		return
+	}
+	s.closed = true
+	listener := s.listener
+	s.mu.Unlock()
+	if listener != nil {
+		listener.OnClose(reason)
+	}
+}
+
+// engineHostKeyVerifier adapts *internal.Engine to nbssh.HostKeyVerifier.
+type engineHostKeyVerifier struct {
+	engine *internal.Engine
+}
+
+func (v *engineHostKeyVerifier) VerifySSHHostKey(peerAddress string, presented []byte) error {
+	storedKey, found := v.engine.GetPeerSSHKey(peerAddress)
+	if !found {
+		return nbssh.ErrPeerNotFound
+	}
+	return nbssh.VerifyHostKey(storedKey, presented, peerAddress)
+}
+
+func detectServerType(host string, port int, dialer *net.Dialer) detection.ServerType {
+	ctx, cancel := context.WithTimeout(context.Background(), sshDetectionTimeout)
+	defer cancel()
+
+	serverType, err := detection.DetectSSHServerType(ctx, dialer, host, port)
+	if err != nil {
+		log.Debugf("ssh: server detection for %s:%d failed: %v (assuming regular SSH)", host, port, err)
+		return detection.ServerTypeRegular
+	}
+	return serverType
+}
+
+// makeWGDialer returns a net.Dialer whose sockets are bound to the WireGuard
+// interface (wgIface, e.g. "utun100"). This is required in the iOS Network
+// Extension process, where the OS deliberately excludes the provider's own
+// traffic from the VPN tunnel to prevent routing loops. Without binding to
+// the WireGuard interface, TCP connections to NetBird peer IPs (100.x.x.x
+// CGNAT space) would be sent over the physical network and fail with
+// "network is unreachable". Falls back to an unbound dialer if the interface
+// cannot be found (e.g. tunnel not yet up).
+func makeWGDialer(wgIface string, timeout time.Duration) *net.Dialer {
+	return &net.Dialer{
+		Timeout: timeout,
+		Control: func(network, address string, c syscall.RawConn) error {
+			iface, err := net.InterfaceByName(wgIface)
+			if err != nil {
+				log.Debugf("ssh: WG interface %q not found, dialing without bind: %v", wgIface, err)
+				return nil
+			}
+			var innerErr error
+			if ctrlErr := c.Control(func(fd uintptr) {
+				// IP_BOUND_IF (Darwin) = 25: binds the socket to a specific interface index.
+				innerErr = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, 25, iface.Index)
+			}); ctrlErr != nil {
+				return ctrlErr
+			}
+			if innerErr != nil {
+				log.Debugf("ssh: IP_BOUND_IF bind to %q failed: %v", wgIface, innerErr)
+			}
+			return innerErr
+		},
+	}
+}
+
+func closeQuiet(c io.Closer, label string) {
+	if c == nil {
+		return
+	}
+	if err := c.Close(); err != nil && !errors.Is(err, io.EOF) {
+		log.Debugf("ssh: close %s: %v", label, err)
+	}
+}

client/server/jwt_cache.go

@@ -1,79 +0,0 @@
-package server
-
-import (
-	"sync"
-	"time"
-
-	"github.com/awnumar/memguard"
-	log "github.com/sirupsen/logrus"
-)
-
-type jwtCache struct {
-	mu           sync.RWMutex
-	enclave      *memguard.Enclave
-	expiresAt    time.Time
-	timer        *time.Timer
-	maxTokenSize int
-}
-
-func newJWTCache() *jwtCache {
-	return &jwtCache{
-		maxTokenSize: 8192,
-	}
-}
-
-func (c *jwtCache) store(token string, maxAge time.Duration) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	c.cleanup()
-
-	if c.timer != nil {
-		c.timer.Stop()
-	}
-
-	tokenBytes := []byte(token)
-	c.enclave = memguard.NewEnclave(tokenBytes)
-
-	c.expiresAt = time.Now().Add(maxAge)
-
-	var timer *time.Timer
-	timer = time.AfterFunc(maxAge, func() {
-		c.mu.Lock()
-		defer c.mu.Unlock()
-		if c.timer != timer {
-			return
-		}
-		c.cleanup()
-		c.timer = nil
-		log.Debugf("JWT token cache expired after %v, securely wiped from memory", maxAge)
-	})
-	c.timer = timer
-}
-
-func (c *jwtCache) get() (string, bool) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
-	if c.enclave == nil || time.Now().After(c.expiresAt) {
-		return "", false
-	}
-
-	buffer, err := c.enclave.Open()
-	if err != nil {
-		log.Debugf("Failed to open JWT token enclave: %v", err)
-		return "", false
-	}
-	defer buffer.Destroy()
-
-	token := string(buffer.Bytes())
-	return token, true
-}
-
-// cleanup destroys the secure enclave, must be called with lock held
-func (c *jwtCache) cleanup() {
-	if c.enclave != nil {
-		c.enclave = nil
-	}
-	c.expiresAt = time.Time{}
-}

client/server/server.go

@@ -26,6 +26,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	sleephandler "github.com/netbirdio/netbird/client/internal/sleep/handler"
 	"github.com/netbirdio/netbird/client/mdm"
+	"github.com/netbirdio/netbird/client/ssh/jwtcache"
 	"github.com/netbirdio/netbird/client/system"
 	mgm "github.com/netbirdio/netbird/shared/management/client"
 	"github.com/netbirdio/netbird/shared/management/domain"
@@ -50,9 +51,6 @@ const (
 	defaultMaxRetryTime     = 14 * 24 * time.Hour
 	defaultRetryMultiplier  = 1.7
 
-	// JWT token cache TTL for the client daemon (disabled by default)
-	defaultJWTCacheTTL = 0
-
 	errRestoreResidualState   = "failed to restore residual state: %v"
 	errProfilesDisabled       = "profiles are disabled, you cannot use this feature without profiles enabled"
 	errUpdateSettingsDisabled = "update settings are disabled, you cannot use this feature without update settings enabled"
@@ -134,7 +132,7 @@ type Server struct {
 
 	updateManager *updater.Manager
 
-	jwtCache *jwtCache
+	jwtCache *jwtcache.Cache
 }
 
 type oauthAuthFlow struct {
@@ -156,7 +154,7 @@ func New(ctx context.Context, logFile string, configFile string, profilesDisable
 		updateSettingsDisabled: updateSettingsDisabled,
 		captureEnabled:         captureEnabled,
 		networksDisabled:       networksDisabled,
-		jwtCache:               newJWTCache(),
+		jwtCache:               jwtcache.New(),
 		extendAuthSessionFlow:  auth.NewPendingFlow(),
 		probeThrottle:          newProbeThrottle(probeThreshold),
 	}
@@ -1624,19 +1622,11 @@ func (s *Server) getJWTCacheTTL() time.Duration {
 	config := s.config
 	s.mutex.Unlock()
 
-	if config == nil || config.SSHJWTCacheTTL == nil {
-		return defaultJWTCacheTTL
+	if config == nil {
+		return jwtcache.DefaultTTL
 	}
 
-	seconds := *config.SSHJWTCacheTTL
-	if seconds == 0 {
-		log.Debug("SSH JWT cache disabled (configured to 0)")
-		return 0
-	}
-
-	ttl := time.Duration(seconds) * time.Second
-	log.Debugf("SSH JWT cache TTL set to %v from config", ttl)
-	return ttl
+	return jwtcache.ResolveTTL(config.SSHJWTCacheTTL)
 }
 
 // RequestJWTAuth initiates JWT authentication flow for SSH
@@ -1658,7 +1648,7 @@ func (s *Server) RequestJWTAuth(
 
 	jwtCacheTTL := s.getJWTCacheTTL()
 	if jwtCacheTTL > 0 {
-		if cachedToken, found := s.jwtCache.get(); found {
+		if cachedToken, found := s.jwtCache.Get(); found {
 			log.Debugf("JWT token found in cache, returning cached token for SSH authentication")
 
 			return &proto.RequestJWTAuthResponse{
@@ -1731,7 +1721,7 @@ func (s *Server) WaitJWTToken(
 
 	jwtCacheTTL := s.getJWTCacheTTL()
 	if jwtCacheTTL > 0 {
-		s.jwtCache.store(token, jwtCacheTTL)
+		s.jwtCache.Store(token, jwtCacheTTL)
 		log.Debugf("JWT token cached for SSH authentication, TTL: %v", jwtCacheTTL)
 	} else {
 		log.Debug("JWT caching disabled, not storing token")

client/ssh/jwtcache/cache.go

@@ -0,0 +1,109 @@
+// Package jwtcache provides an in-memory, TTL-bound cache for SSH JWT tokens.
+// The token is kept in a secure memguard enclave and wiped from memory when it
+// expires. It is shared by the daemon gRPC server and the mobile SDKs, which
+// have no daemon process to delegate caching to.
+package jwtcache
+
+import (
+	"sync"
+	"time"
+
+	"github.com/awnumar/memguard"
+	log "github.com/sirupsen/logrus"
+)
+
+// DefaultTTL is used when no TTL is configured: caching disabled.
+const DefaultTTL = 0
+
+// Cache stores a single JWT token in a secure enclave until it expires.
+type Cache struct {
+	mu           sync.RWMutex
+	enclave      *memguard.Enclave
+	expiresAt    time.Time
+	timer        *time.Timer
+	maxTokenSize int
+}
+
+// New creates an empty Cache.
+func New() *Cache {
+	return &Cache{
+		maxTokenSize: 8192,
+	}
+}
+
+// Store caches the token for maxAge. A previously stored token is wiped.
+func (c *Cache) Store(token string, maxAge time.Duration) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.cleanup()
+
+	if c.timer != nil {
+		c.timer.Stop()
+	}
+
+	tokenBytes := []byte(token)
+	c.enclave = memguard.NewEnclave(tokenBytes)
+
+	c.expiresAt = time.Now().Add(maxAge)
+
+	var timer *time.Timer
+	timer = time.AfterFunc(maxAge, func() {
+		c.mu.Lock()
+		defer c.mu.Unlock()
+		if c.timer != timer {
+			return
+		}
+		c.cleanup()
+		c.timer = nil
+		log.Debugf("JWT token cache expired after %v, securely wiped from memory", maxAge)
+	})
+	c.timer = timer
+}
+
+// Get returns the cached token, or false if none is stored or it has expired.
+func (c *Cache) Get() (string, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if c.enclave == nil || time.Now().After(c.expiresAt) {
+		return "", false
+	}
+
+	buffer, err := c.enclave.Open()
+	if err != nil {
+		log.Debugf("Failed to open JWT token enclave: %v", err)
+		return "", false
+	}
+	defer buffer.Destroy()
+
+	token := string(buffer.Bytes())
+	return token, true
+}
+
+// cleanup destroys the secure enclave, must be called with lock held
+func (c *Cache) cleanup() {
+	if c.enclave != nil {
+		c.enclave = nil
+	}
+	c.expiresAt = time.Time{}
+}
+
+// ResolveTTL converts the configured TTL (seconds, from
+// profilemanager.Config.SSHJWTCacheTTL) into a duration. Returns DefaultTTL
+// when unset; 0 means caching is disabled.
+func ResolveTTL(configuredSeconds *int) time.Duration {
+	if configuredSeconds == nil {
+		return DefaultTTL
+	}
+
+	seconds := *configuredSeconds
+	if seconds == 0 {
+		log.Debug("SSH JWT cache disabled (configured to 0)")
+		return 0
+	}
+
+	ttl := time.Duration(seconds) * time.Second
+	log.Debugf("SSH JWT cache TTL set to %v from config", ttl)
+	return ttl
+}