[client] Add port forwarding to ssh proxy (#5031)

* Implement port forwarding for the ssh proxy

* Allow user switching for port forwarding

client/ssh/auth/auth.go

@@ -98,19 +98,17 @@ func (a *Authorizer) Update(config *Config) {
 		len(config.AuthorizedUsers), len(machineUsers))
 }
 
-// Authorize validates if a user is authorized to login as the specified OS user
-// Returns nil if authorized, or an error describing why authorization failed
-func (a *Authorizer) Authorize(jwtUserID, osUsername string) error {
+// Authorize validates if a user is authorized to login as the specified OS user.
+// Returns a success message describing how authorization was granted, or an error.
+func (a *Authorizer) Authorize(jwtUserID, osUsername string) (string, error) {
 	if jwtUserID == "" {
-		log.Warnf("SSH auth denied: JWT user ID is empty for OS user '%s'", osUsername)
-		return ErrEmptyUserID
+		return "", fmt.Errorf("JWT user ID is empty for OS user %q: %w", osUsername, ErrEmptyUserID)
 	}
 
 	// Hash the JWT user ID for comparison
 	hashedUserID, err := sshuserhash.HashUserID(jwtUserID)
 	if err != nil {
-		log.Errorf("SSH auth denied: failed to hash user ID '%s' for OS user '%s': %v", jwtUserID, osUsername, err)
-		return fmt.Errorf("failed to hash user ID: %w", err)
+		return "", fmt.Errorf("hash user ID %q for OS user %q: %w", jwtUserID, osUsername, err)
 	}
 
 	a.mu.RLock()
@@ -119,8 +117,7 @@ func (a *Authorizer) Authorize(jwtUserID, osUsername string) error {
 	// Find the index of this user in the authorized list
 	userIndex, found := a.findUserIndex(hashedUserID)
 	if !found {
-		log.Warnf("SSH auth denied: user '%s' (hash: %s) not in authorized list for OS user '%s'", jwtUserID, hashedUserID, osUsername)
-		return ErrUserNotAuthorized
+		return "", fmt.Errorf("user %q (hash: %s) not in authorized list for OS user %q: %w", jwtUserID, hashedUserID, osUsername, ErrUserNotAuthorized)
 	}
 
 	return a.checkMachineUserMapping(jwtUserID, osUsername, userIndex)
@@ -128,12 +125,11 @@ func (a *Authorizer) Authorize(jwtUserID, osUsername string) error {
 
 // checkMachineUserMapping validates if a user's index is authorized for the specified OS user
 // Checks wildcard mapping first, then specific OS user mappings
-func (a *Authorizer) checkMachineUserMapping(jwtUserID, osUsername string, userIndex int) error {
+func (a *Authorizer) checkMachineUserMapping(jwtUserID, osUsername string, userIndex int) (string, error) {
 	// If wildcard exists and user's index is in the wildcard list, allow access to any OS user
 	if wildcardIndexes, hasWildcard := a.machineUsers[Wildcard]; hasWildcard {
 		if a.isIndexInList(uint32(userIndex), wildcardIndexes) {
-			log.Infof("SSH auth granted: user '%s' authorized for OS user '%s' via wildcard (index: %d)", jwtUserID, osUsername, userIndex)
-			return nil
+			return fmt.Sprintf("granted via wildcard (index: %d)", userIndex), nil
 		}
 	}
 
@@ -141,18 +137,15 @@ func (a *Authorizer) checkMachineUserMapping(jwtUserID, osUsername string, userI
 	allowedIndexes, hasMachineUserMapping := a.machineUsers[osUsername]
 	if !hasMachineUserMapping {
 		// No mapping for this OS user - deny by default (fail closed)
-		log.Warnf("SSH auth denied: no machine user mapping for OS user '%s' (JWT user: %s)", osUsername, jwtUserID)
-		return ErrNoMachineUserMapping
+		return "", fmt.Errorf("no machine user mapping for OS user %q (JWT user: %s): %w", osUsername, jwtUserID, ErrNoMachineUserMapping)
 	}
 
 	// Check if user's index is in the allowed indexes for this specific OS user
 	if !a.isIndexInList(uint32(userIndex), allowedIndexes) {
-		log.Warnf("SSH auth denied: user '%s' not mapped to OS user '%s' (user index: %d)", jwtUserID, osUsername, userIndex)
-		return ErrUserNotMappedToOSUser
+		return "", fmt.Errorf("user %q not mapped to OS user %q (index: %d): %w", jwtUserID, osUsername, userIndex, ErrUserNotMappedToOSUser)
 	}
 
-	log.Infof("SSH auth granted: user '%s' authorized for OS user '%s' (index: %d)", jwtUserID, osUsername, userIndex)
-	return nil
+	return fmt.Sprintf("granted (index: %d)", userIndex), nil
 }
 
 // GetUserIDClaim returns the JWT claim name used to extract user IDs

client/ssh/auth/auth_test.go

@@ -24,7 +24,7 @@ func TestAuthorizer_Authorize_UserNotInList(t *testing.T) {
 	authorizer.Update(config)
 
 	// Try to authorize a different user
-	err = authorizer.Authorize("unauthorized-user", "root")
+	_, err = authorizer.Authorize("unauthorized-user", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotAuthorized)
 }
@@ -45,15 +45,15 @@ func TestAuthorizer_Authorize_UserInList_NoMachineUserRestrictions(t *testing.T)
 	authorizer.Update(config)
 
 	// All attempts should fail when no machine user mappings exist (fail closed)
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
-	err = authorizer.Authorize("user2", "admin")
+	_, err = authorizer.Authorize("user2", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 }
@@ -80,21 +80,21 @@ func TestAuthorizer_Authorize_UserInList_WithMachineUserMapping_Allowed(t *testi
 	authorizer.Update(config)
 
 	// user1 (index 0) should access root and admin
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user1", "admin")
+	_, err = authorizer.Authorize("user1", "admin")
 	assert.NoError(t, err)
 
 	// user2 (index 1) should access root and postgres
-	err = authorizer.Authorize("user2", "root")
+	_, err = authorizer.Authorize("user2", "root")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user2", "postgres")
+	_, err = authorizer.Authorize("user2", "postgres")
 	assert.NoError(t, err)
 
 	// user3 (index 2) should access postgres
-	err = authorizer.Authorize("user3", "postgres")
+	_, err = authorizer.Authorize("user3", "postgres")
 	assert.NoError(t, err)
 }
 
@@ -121,22 +121,22 @@ func TestAuthorizer_Authorize_UserInList_WithMachineUserMapping_Denied(t *testin
 	authorizer.Update(config)
 
 	// user1 (index 0) should NOT access postgres
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 
 	// user2 (index 1) should NOT access admin
-	err = authorizer.Authorize("user2", "admin")
+	_, err = authorizer.Authorize("user2", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 
 	// user3 (index 2) should NOT access root
-	err = authorizer.Authorize("user3", "root")
+	_, err = authorizer.Authorize("user3", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 
 	// user3 (index 2) should NOT access admin
-	err = authorizer.Authorize("user3", "admin")
+	_, err = authorizer.Authorize("user3", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 }
@@ -158,7 +158,7 @@ func TestAuthorizer_Authorize_UserInList_OSUserNotInMapping(t *testing.T) {
 	authorizer.Update(config)
 
 	// user1 should NOT access an unmapped OS user (fail closed)
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 }
@@ -178,7 +178,7 @@ func TestAuthorizer_Authorize_EmptyJWTUserID(t *testing.T) {
 	authorizer.Update(config)
 
 	// Empty user ID should fail
-	err = authorizer.Authorize("", "root")
+	_, err = authorizer.Authorize("", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrEmptyUserID)
 }
@@ -211,12 +211,12 @@ func TestAuthorizer_Authorize_MultipleUsersInList(t *testing.T) {
 
 	// All users should be authorized for root
 	for i := 0; i < 10; i++ {
-		err := authorizer.Authorize("user"+string(rune('0'+i)), "root")
+		_, err := authorizer.Authorize("user"+string(rune('0'+i)), "root")
 		assert.NoError(t, err, "user%d should be authorized", i)
 	}
 
 	// User not in list should fail
-	err := authorizer.Authorize("unknown-user", "root")
+	_, err := authorizer.Authorize("unknown-user", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotAuthorized)
 }
@@ -236,14 +236,14 @@ func TestAuthorizer_Update_ClearsConfiguration(t *testing.T) {
 	authorizer.Update(config)
 
 	// user1 should be authorized
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
 	// Clear configuration
 	authorizer.Update(nil)
 
 	// user1 should no longer be authorized
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotAuthorized)
 }
@@ -267,16 +267,16 @@ func TestAuthorizer_Update_EmptyMachineUsersListEntries(t *testing.T) {
 	authorizer.Update(config)
 
 	// root should work
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
 	// postgres should fail (no mapping)
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
 	// admin should fail (no mapping)
-	err = authorizer.Authorize("user1", "admin")
+	_, err = authorizer.Authorize("user1", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 }
@@ -301,7 +301,7 @@ func TestAuthorizer_CustomUserIDClaim(t *testing.T) {
 	assert.Equal(t, "email", authorizer.GetUserIDClaim())
 
 	// Authorize with email as user ID
-	err = authorizer.Authorize("user@example.com", "root")
+	_, err = authorizer.Authorize("user@example.com", "root")
 	assert.NoError(t, err)
 }
 
@@ -349,19 +349,19 @@ func TestAuthorizer_MachineUserMapping_LargeIndexes(t *testing.T) {
 	authorizer.Update(config)
 
 	// First user should have access
-	err := authorizer.Authorize("user"+string(rune(0)), "root")
+	_, err := authorizer.Authorize("user"+string(rune(0)), "root")
 	assert.NoError(t, err)
 
 	// Middle user should have access
-	err = authorizer.Authorize("user"+string(rune(500)), "root")
+	_, err = authorizer.Authorize("user"+string(rune(500)), "root")
 	assert.NoError(t, err)
 
 	// Last user should have access
-	err = authorizer.Authorize("user"+string(rune(999)), "root")
+	_, err = authorizer.Authorize("user"+string(rune(999)), "root")
 	assert.NoError(t, err)
 
 	// User not in mapping should NOT have access
-	err = authorizer.Authorize("user"+string(rune(100)), "root")
+	_, err = authorizer.Authorize("user"+string(rune(100)), "root")
 	assert.Error(t, err)
 }
 
@@ -393,7 +393,7 @@ func TestAuthorizer_ConcurrentAuthorization(t *testing.T) {
 			if idx%2 == 0 {
 				user = "user2"
 			}
-			err := authorizer.Authorize(user, "root")
+			_, err := authorizer.Authorize(user, "root")
 			errChan <- err
 		}(i)
 	}
@@ -426,22 +426,22 @@ func TestAuthorizer_Wildcard_AllowsAllAuthorizedUsers(t *testing.T) {
 	authorizer.Update(config)
 
 	// All authorized users should be able to access any OS user
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user2", "postgres")
+	_, err = authorizer.Authorize("user2", "postgres")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user3", "admin")
+	_, err = authorizer.Authorize("user3", "admin")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user1", "ubuntu")
+	_, err = authorizer.Authorize("user1", "ubuntu")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user2", "nginx")
+	_, err = authorizer.Authorize("user2", "nginx")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user3", "docker")
+	_, err = authorizer.Authorize("user3", "docker")
 	assert.NoError(t, err)
 }
 
@@ -462,11 +462,11 @@ func TestAuthorizer_Wildcard_UnauthorizedUserStillDenied(t *testing.T) {
 	authorizer.Update(config)
 
 	// user1 should have access
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
 	// Unauthorized user should still be denied even with wildcard
-	err = authorizer.Authorize("unauthorized-user", "root")
+	_, err = authorizer.Authorize("unauthorized-user", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotAuthorized)
 }
@@ -492,17 +492,17 @@ func TestAuthorizer_Wildcard_TakesPrecedenceOverSpecificMappings(t *testing.T) {
 	authorizer.Update(config)
 
 	// Both users should be able to access root via wildcard (takes precedence over specific mapping)
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user2", "root")
+	_, err = authorizer.Authorize("user2", "root")
 	assert.NoError(t, err)
 
 	// Both users should be able to access any other OS user via wildcard
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.NoError(t, err)
 
-	err = authorizer.Authorize("user2", "admin")
+	_, err = authorizer.Authorize("user2", "admin")
 	assert.NoError(t, err)
 }
 
@@ -526,29 +526,29 @@ func TestAuthorizer_NoWildcard_SpecificMappingsOnly(t *testing.T) {
 	authorizer.Update(config)
 
 	// user1 can access root
-	err = authorizer.Authorize("user1", "root")
+	_, err = authorizer.Authorize("user1", "root")
 	assert.NoError(t, err)
 
 	// user2 can access postgres
-	err = authorizer.Authorize("user2", "postgres")
+	_, err = authorizer.Authorize("user2", "postgres")
 	assert.NoError(t, err)
 
 	// user1 cannot access postgres
-	err = authorizer.Authorize("user1", "postgres")
+	_, err = authorizer.Authorize("user1", "postgres")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 
 	// user2 cannot access root
-	err = authorizer.Authorize("user2", "root")
+	_, err = authorizer.Authorize("user2", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotMappedToOSUser)
 
 	// Neither can access unmapped OS users
-	err = authorizer.Authorize("user1", "admin")
+	_, err = authorizer.Authorize("user1", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
-	err = authorizer.Authorize("user2", "admin")
+	_, err = authorizer.Authorize("user2", "admin")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 }
@@ -578,35 +578,35 @@ func TestAuthorizer_Wildcard_WithPartialIndexes_AllowsAllUsers(t *testing.T) {
 	authorizer.Update(config)
 
 	// wasm (index 0) should access any OS user via wildcard
-	err = authorizer.Authorize("wasm", "root")
+	_, err = authorizer.Authorize("wasm", "root")
 	assert.NoError(t, err, "wasm should access root via wildcard")
 
-	err = authorizer.Authorize("wasm", "alice")
+	_, err = authorizer.Authorize("wasm", "alice")
 	assert.NoError(t, err, "wasm should access alice via wildcard")
 
-	err = authorizer.Authorize("wasm", "bob")
+	_, err = authorizer.Authorize("wasm", "bob")
 	assert.NoError(t, err, "wasm should access bob via wildcard")
 
-	err = authorizer.Authorize("wasm", "postgres")
+	_, err = authorizer.Authorize("wasm", "postgres")
 	assert.NoError(t, err, "wasm should access postgres via wildcard")
 
 	// user2 (index 1) should only access alice and bob (explicitly mapped), NOT root or postgres
-	err = authorizer.Authorize("user2", "alice")
+	_, err = authorizer.Authorize("user2", "alice")
 	assert.NoError(t, err, "user2 should access alice via explicit mapping")
 
-	err = authorizer.Authorize("user2", "bob")
+	_, err = authorizer.Authorize("user2", "bob")
 	assert.NoError(t, err, "user2 should access bob via explicit mapping")
 
-	err = authorizer.Authorize("user2", "root")
+	_, err = authorizer.Authorize("user2", "root")
 	assert.Error(t, err, "user2 should NOT access root (not in wildcard indexes)")
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
-	err = authorizer.Authorize("user2", "postgres")
+	_, err = authorizer.Authorize("user2", "postgres")
 	assert.Error(t, err, "user2 should NOT access postgres (not explicitly mapped)")
 	assert.ErrorIs(t, err, ErrNoMachineUserMapping)
 
 	// Unauthorized user should still be denied
-	err = authorizer.Authorize("user3", "root")
+	_, err = authorizer.Authorize("user3", "root")
 	assert.Error(t, err)
 	assert.ErrorIs(t, err, ErrUserNotAuthorized, "unauthorized user should be denied")
 }

client/ssh/client/client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io"
 	"net"
 	"os"
 	"path/filepath"
@@ -551,14 +550,15 @@ func (c *Client) LocalPortForward(ctx context.Context, localAddr, remoteAddr str
 func (c *Client) handleLocalForward(localConn net.Conn, remoteAddr string) {
 	defer func() {
 		if err := localConn.Close(); err != nil {
-			log.Debugf("local connection close error: %v", err)
+			log.Debugf("local port forwarding: close local connection: %v", err)
 		}
 	}()
 
 	channel, err := c.client.Dial("tcp", remoteAddr)
 	if err != nil {
-		if strings.Contains(err.Error(), "administratively prohibited") {
-			_, _ = fmt.Fprintf(os.Stderr, "channel open failed: administratively prohibited: port forwarding is disabled\n")
+		var openErr *ssh.OpenChannelError
+		if errors.As(err, &openErr) && openErr.Reason == ssh.Prohibited {
+			_, _ = fmt.Fprintf(os.Stderr, "channel open failed: port forwarding is disabled\n")
 		} else {
 			log.Debugf("local port forwarding to %s failed: %v", remoteAddr, err)
 		}
@@ -566,19 +566,11 @@ func (c *Client) handleLocalForward(localConn net.Conn, remoteAddr string) {
 	}
 	defer func() {
 		if err := channel.Close(); err != nil {
-			log.Debugf("remote channel close error: %v", err)
+			log.Debugf("local port forwarding: close remote channel: %v", err)
 		}
 	}()
 
-	go func() {
-		if _, err := io.Copy(channel, localConn); err != nil {
-			log.Debugf("local forward copy error (local->remote): %v", err)
-		}
-	}()
-
-	if _, err := io.Copy(localConn, channel); err != nil {
-		log.Debugf("local forward copy error (remote->local): %v", err)
-	}
+	nbssh.BidirectionalCopy(log.NewEntry(log.StandardLogger()), localConn, channel)
 }
 
 // RemotePortForward sets up remote port forwarding, binding on remote and forwarding to localAddr
@@ -633,7 +625,7 @@ func (c *Client) sendTCPIPForwardRequest(req tcpipForwardMsg) error {
 		return fmt.Errorf("send tcpip-forward request: %w", err)
 	}
 	if !ok {
-		return fmt.Errorf("remote port forwarding denied by server (check if --allow-ssh-remote-port-forwarding is enabled)")
+		return fmt.Errorf("remote port forwarding denied by server")
 	}
 	return nil
 }
@@ -676,7 +668,7 @@ func (c *Client) handleRemoteForwardChannel(newChan ssh.NewChannel, localAddr st
 	}
 	defer func() {
 		if err := channel.Close(); err != nil {
-			log.Debugf("remote channel close error: %v", err)
+			log.Debugf("remote port forwarding: close remote channel: %v", err)
 		}
 	}()
 
@@ -688,19 +680,11 @@ func (c *Client) handleRemoteForwardChannel(newChan ssh.NewChannel, localAddr st
 	}
 	defer func() {
 		if err := localConn.Close(); err != nil {
-			log.Debugf("local connection close error: %v", err)
+			log.Debugf("remote port forwarding: close local connection: %v", err)
 		}
 	}()
 
-	go func() {
-		if _, err := io.Copy(localConn, channel); err != nil {
-			log.Debugf("remote forward copy error (remote->local): %v", err)
-		}
-	}()
-
-	if _, err := io.Copy(channel, localConn); err != nil {
-		log.Debugf("remote forward copy error (local->remote): %v", err)
-	}
+	nbssh.BidirectionalCopy(log.NewEntry(log.StandardLogger()), localConn, channel)
 }
 
 // tcpipForwardMsg represents the structure for tcpip-forward requests

client/ssh/common.go

@@ -193,3 +193,64 @@ func buildAddressList(hostname string, remote net.Addr) []string {
 	}
 	return addresses
 }
+
+// BidirectionalCopy copies data bidirectionally between two io.ReadWriter connections.
+// It waits for both directions to complete before returning.
+// The caller is responsible for closing the connections.
+func BidirectionalCopy(logger *log.Entry, rw1, rw2 io.ReadWriter) {
+	done := make(chan struct{}, 2)
+
+	go func() {
+		if _, err := io.Copy(rw2, rw1); err != nil && !isExpectedCopyError(err) {
+			logger.Debugf("copy error (1->2): %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	go func() {
+		if _, err := io.Copy(rw1, rw2); err != nil && !isExpectedCopyError(err) {
+			logger.Debugf("copy error (2->1): %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	<-done
+	<-done
+}
+
+func isExpectedCopyError(err error) bool {
+	return errors.Is(err, io.EOF) || errors.Is(err, context.Canceled)
+}
+
+// BidirectionalCopyWithContext copies data bidirectionally between two io.ReadWriteCloser connections.
+// It waits for both directions to complete or for context cancellation before returning.
+// Both connections are closed when the function returns.
+func BidirectionalCopyWithContext(logger *log.Entry, ctx context.Context, conn1, conn2 io.ReadWriteCloser) {
+	done := make(chan struct{}, 2)
+
+	go func() {
+		if _, err := io.Copy(conn2, conn1); err != nil && !isExpectedCopyError(err) {
+			logger.Debugf("copy error (1->2): %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	go func() {
+		if _, err := io.Copy(conn1, conn2); err != nil && !isExpectedCopyError(err) {
+			logger.Debugf("copy error (2->1): %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	select {
+	case <-ctx.Done():
+	case <-done:
+		select {
+		case <-ctx.Done():
+		case <-done:
+		}
+	}
+
+	_ = conn1.Close()
+	_ = conn2.Close()
+}

client/ssh/proxy/proxy.go

@@ -2,6 +2,7 @@ package proxy
 
 import (
 	"context"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"io"
@@ -42,6 +43,14 @@ type SSHProxy struct {
 	conn          *grpc.ClientConn
 	daemonClient  proto.DaemonServiceClient
 	browserOpener func(string) error
+
+	mu            sync.RWMutex
+	backendClient *cryptossh.Client
+	// jwtToken is set once in runProxySSHServer before any handlers are called,
+	// so concurrent access is safe without additional synchronization.
+	jwtToken string
+
+	forwardedChannelsOnce sync.Once
 }
 
 func New(daemonAddr, targetHost string, targetPort int, stderr io.Writer, browserOpener func(string) error) (*SSHProxy, error) {
@@ -63,6 +72,17 @@ func New(daemonAddr, targetHost string, targetPort int, stderr io.Writer, browse
 }
 
 func (p *SSHProxy) Close() error {
+	p.mu.Lock()
+	backendClient := p.backendClient
+	p.backendClient = nil
+	p.mu.Unlock()
+
+	if backendClient != nil {
+		if err := backendClient.Close(); err != nil {
+			log.Debugf("close backend client: %v", err)
+		}
+	}
+
 	if p.conn != nil {
 		return p.conn.Close()
 	}
@@ -77,16 +97,16 @@ func (p *SSHProxy) Connect(ctx context.Context) error {
 		return fmt.Errorf(jwtAuthErrorMsg, err)
 	}
 
-	return p.runProxySSHServer(ctx, jwtToken)
+	log.Debugf("JWT authentication successful, starting proxy to %s:%d", p.targetHost, p.targetPort)
+	return p.runProxySSHServer(jwtToken)
 }
 
-func (p *SSHProxy) runProxySSHServer(ctx context.Context, jwtToken string) error {
+func (p *SSHProxy) runProxySSHServer(jwtToken string) error {
+	p.jwtToken = jwtToken
 	serverVersion := fmt.Sprintf("%s-%s", detection.ProxyIdentifier, version.NetbirdVersion())
 
 	sshServer := &ssh.Server{
-		Handler: func(s ssh.Session) {
-			p.handleSSHSession(ctx, s, jwtToken)
-		},
+		Handler: p.handleSSHSession,
 		ChannelHandlers: map[string]ssh.ChannelHandler{
 			"session":      ssh.DefaultSessionHandler,
 			"direct-tcpip": p.directTCPIPHandler,
@@ -119,15 +139,20 @@ func (p *SSHProxy) runProxySSHServer(ctx context.Context, jwtToken string) error
 	return nil
 }
 
-func (p *SSHProxy) handleSSHSession(ctx context.Context, session ssh.Session, jwtToken string) {
-	targetAddr := net.JoinHostPort(p.targetHost, strconv.Itoa(p.targetPort))
+func (p *SSHProxy) handleSSHSession(session ssh.Session) {
+	ptyReq, winCh, isPty := session.Pty()
+	hasCommand := len(session.Command()) > 0
 
-	sshClient, err := p.dialBackend(ctx, targetAddr, session.User(), jwtToken)
+	sshClient, err := p.getOrCreateBackendClient(session.Context(), session.User())
 	if err != nil {
 		_, _ = fmt.Fprintf(p.stderr, "SSH connection to NetBird server failed: %v\n", err)
 		return
 	}
-	defer func() { _ = sshClient.Close() }()
+
+	if !isPty && !hasCommand {
+		p.handleNonInteractiveSession(session, sshClient)
+		return
+	}
 
 	serverSession, err := sshClient.NewSession()
 	if err != nil {
@@ -140,7 +165,6 @@ func (p *SSHProxy) handleSSHSession(ctx context.Context, session ssh.Session, jw
 	serverSession.Stdout = session
 	serverSession.Stderr = session.Stderr()
 
-	ptyReq, winCh, isPty := session.Pty()
 	if isPty {
 		if err := serverSession.RequestPty(ptyReq.Term, ptyReq.Window.Width, ptyReq.Window.Height, nil); err != nil {
 			log.Debugf("PTY request to backend: %v", err)
@@ -155,7 +179,7 @@ func (p *SSHProxy) handleSSHSession(ctx context.Context, session ssh.Session, jw
 		}()
 	}
 
-	if len(session.Command()) > 0 {
+	if hasCommand {
 		if err := serverSession.Run(strings.Join(session.Command(), " ")); err != nil {
 			log.Debugf("run command: %v", err)
 			p.handleProxyExitCode(session, err)
@@ -176,12 +200,29 @@ func (p *SSHProxy) handleSSHSession(ctx context.Context, session ssh.Session, jw
 func (p *SSHProxy) handleProxyExitCode(session ssh.Session, err error) {
 	var exitErr *cryptossh.ExitError
 	if errors.As(err, &exitErr) {
-		if exitErr := session.Exit(exitErr.ExitStatus()); exitErr != nil {
-			log.Debugf("set exit status: %v", exitErr)
+		if err := session.Exit(exitErr.ExitStatus()); err != nil {
+			log.Debugf("set exit status: %v", err)
 		}
 	}
 }
 
+func (p *SSHProxy) handleNonInteractiveSession(session ssh.Session, sshClient *cryptossh.Client) {
+	// Create a backend session to mirror the client's session request.
+	// This keeps the connection alive on the server side while port forwarding channels operate.
+	serverSession, err := sshClient.NewSession()
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "create server session: %v\n", err)
+		return
+	}
+	defer func() { _ = serverSession.Close() }()
+
+	<-session.Context().Done()
+
+	if err := session.Exit(0); err != nil {
+		log.Debugf("session exit: %v", err)
+	}
+}
+
 func generateHostKey() (ssh.Signer, error) {
 	keyPEM, err := nbssh.GeneratePrivateKey(nbssh.ED25519)
 	if err != nil {
@@ -250,8 +291,52 @@ func (c *stdioConn) SetWriteDeadline(_ time.Time) error {
 	return nil
 }
 
-func (p *SSHProxy) directTCPIPHandler(_ *ssh.Server, _ *cryptossh.ServerConn, newChan cryptossh.NewChannel, _ ssh.Context) {
-	_ = newChan.Reject(cryptossh.Prohibited, "port forwarding not supported in proxy")
+// directTCPIPHandler handles local port forwarding (direct-tcpip channel).
+func (p *SSHProxy) directTCPIPHandler(_ *ssh.Server, _ *cryptossh.ServerConn, newChan cryptossh.NewChannel, sshCtx ssh.Context) {
+	var payload struct {
+		DestAddr   string
+		DestPort   uint32
+		OriginAddr string
+		OriginPort uint32
+	}
+	if err := cryptossh.Unmarshal(newChan.ExtraData(), &payload); err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "parse direct-tcpip payload: %v\n", err)
+		_ = newChan.Reject(cryptossh.ConnectionFailed, "invalid payload")
+		return
+	}
+
+	dest := fmt.Sprintf("%s:%d", payload.DestAddr, payload.DestPort)
+	log.Debugf("local port forwarding: %s", dest)
+
+	backendClient, err := p.getOrCreateBackendClient(sshCtx, sshCtx.User())
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "backend connection for port forwarding: %v\n", err)
+		_ = newChan.Reject(cryptossh.ConnectionFailed, "backend connection failed")
+		return
+	}
+
+	backendChan, backendReqs, err := backendClient.OpenChannel("direct-tcpip", newChan.ExtraData())
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "open backend channel for %s: %v\n", dest, err)
+		var openErr *cryptossh.OpenChannelError
+		if errors.As(err, &openErr) {
+			_ = newChan.Reject(openErr.Reason, openErr.Message)
+		} else {
+			_ = newChan.Reject(cryptossh.ConnectionFailed, err.Error())
+		}
+		return
+	}
+	go cryptossh.DiscardRequests(backendReqs)
+
+	clientChan, clientReqs, err := newChan.Accept()
+	if err != nil {
+		log.Debugf("local port forwarding: accept channel: %v", err)
+		_ = backendChan.Close()
+		return
+	}
+	go cryptossh.DiscardRequests(clientReqs)
+
+	nbssh.BidirectionalCopyWithContext(log.NewEntry(log.StandardLogger()), sshCtx, clientChan, backendChan)
 }
 
 func (p *SSHProxy) sftpSubsystemHandler(s ssh.Session, jwtToken string) {
@@ -354,12 +439,143 @@ func (p *SSHProxy) runSFTPBridge(ctx context.Context, s ssh.Session, stdin io.Wr
 	}
 }
 
-func (p *SSHProxy) tcpipForwardHandler(_ ssh.Context, _ *ssh.Server, _ *cryptossh.Request) (bool, []byte) {
-	return false, []byte("port forwarding not supported in proxy")
+// tcpipForwardHandler handles remote port forwarding (tcpip-forward request).
+func (p *SSHProxy) tcpipForwardHandler(sshCtx ssh.Context, _ *ssh.Server, req *cryptossh.Request) (bool, []byte) {
+	var reqPayload struct {
+		Host string
+		Port uint32
+	}
+	if err := cryptossh.Unmarshal(req.Payload, &reqPayload); err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "parse tcpip-forward payload: %v\n", err)
+		return false, nil
+	}
+
+	log.Debugf("tcpip-forward request for %s:%d", reqPayload.Host, reqPayload.Port)
+
+	backendClient, err := p.getOrCreateBackendClient(sshCtx, sshCtx.User())
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "backend connection for remote port forwarding: %v\n", err)
+		return false, nil
+	}
+
+	ok, payload, err := backendClient.SendRequest(req.Type, req.WantReply, req.Payload)
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "forward tcpip-forward request for %s:%d: %v\n", reqPayload.Host, reqPayload.Port, err)
+		return false, nil
+	}
+
+	if ok {
+		actualPort := reqPayload.Port
+		if reqPayload.Port == 0 && len(payload) >= 4 {
+			actualPort = binary.BigEndian.Uint32(payload)
+		}
+		log.Debugf("remote port forwarding established for %s:%d", reqPayload.Host, actualPort)
+		p.forwardedChannelsOnce.Do(func() {
+			go p.handleForwardedChannels(sshCtx, backendClient)
+		})
+	}
+
+	return ok, payload
 }
 
-func (p *SSHProxy) cancelTcpipForwardHandler(_ ssh.Context, _ *ssh.Server, _ *cryptossh.Request) (bool, []byte) {
-	return true, nil
+// cancelTcpipForwardHandler handles cancel-tcpip-forward request.
+func (p *SSHProxy) cancelTcpipForwardHandler(_ ssh.Context, _ *ssh.Server, req *cryptossh.Request) (bool, []byte) {
+	var reqPayload struct {
+		Host string
+		Port uint32
+	}
+	if err := cryptossh.Unmarshal(req.Payload, &reqPayload); err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "parse cancel-tcpip-forward payload: %v\n", err)
+		return false, nil
+	}
+
+	log.Debugf("cancel-tcpip-forward request for %s:%d", reqPayload.Host, reqPayload.Port)
+
+	backendClient := p.getBackendClient()
+	if backendClient == nil {
+		return false, nil
+	}
+
+	ok, payload, err := backendClient.SendRequest(req.Type, req.WantReply, req.Payload)
+	if err != nil {
+		_, _ = fmt.Fprintf(p.stderr, "cancel-tcpip-forward for %s:%d: %v\n", reqPayload.Host, reqPayload.Port, err)
+		return false, nil
+	}
+
+	return ok, payload
+}
+
+// getOrCreateBackendClient returns the existing backend client or creates a new one.
+func (p *SSHProxy) getOrCreateBackendClient(ctx context.Context, user string) (*cryptossh.Client, error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.backendClient != nil {
+		return p.backendClient, nil
+	}
+
+	targetAddr := net.JoinHostPort(p.targetHost, strconv.Itoa(p.targetPort))
+	log.Debugf("connecting to backend %s", targetAddr)
+
+	client, err := p.dialBackend(ctx, targetAddr, user, p.jwtToken)
+	if err != nil {
+		return nil, err
+	}
+
+	log.Debugf("backend connection established to %s", targetAddr)
+	p.backendClient = client
+	return client, nil
+}
+
+// getBackendClient returns the existing backend client or nil.
+func (p *SSHProxy) getBackendClient() *cryptossh.Client {
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+	return p.backendClient
+}
+
+// handleForwardedChannels handles forwarded-tcpip channels from the backend for remote port forwarding.
+// When the backend receives incoming connections on the forwarded port, it sends them as
+// "forwarded-tcpip" channels which we need to proxy to the client.
+func (p *SSHProxy) handleForwardedChannels(sshCtx ssh.Context, backendClient *cryptossh.Client) {
+	sshConn, ok := sshCtx.Value(ssh.ContextKeyConn).(*cryptossh.ServerConn)
+	if !ok || sshConn == nil {
+		log.Debugf("no SSH connection in context for forwarded channels")
+		return
+	}
+
+	channelChan := backendClient.HandleChannelOpen("forwarded-tcpip")
+	for {
+		select {
+		case <-sshCtx.Done():
+			return
+		case newChannel, ok := <-channelChan:
+			if !ok {
+				return
+			}
+			go p.handleForwardedChannel(sshCtx, sshConn, newChannel)
+		}
+	}
+}
+
+// handleForwardedChannel handles a single forwarded-tcpip channel from the backend.
+func (p *SSHProxy) handleForwardedChannel(sshCtx ssh.Context, sshConn *cryptossh.ServerConn, newChannel cryptossh.NewChannel) {
+	backendChan, backendReqs, err := newChannel.Accept()
+	if err != nil {
+		log.Debugf("remote port forwarding: accept from backend: %v", err)
+		return
+	}
+	go cryptossh.DiscardRequests(backendReqs)
+
+	clientChan, clientReqs, err := sshConn.OpenChannel("forwarded-tcpip", newChannel.ExtraData())
+	if err != nil {
+		log.Debugf("remote port forwarding: open to client: %v", err)
+		_ = backendChan.Close()
+		return
+	}
+	go cryptossh.DiscardRequests(clientReqs)
+
+	nbssh.BidirectionalCopyWithContext(log.NewEntry(log.StandardLogger()), sshCtx, clientChan, backendChan)
 }
 
 func (p *SSHProxy) dialBackend(ctx context.Context, addr, user, jwtToken string) (*cryptossh.Client, error) {

client/ssh/server/port_forwarding.go

@@ -1,25 +1,32 @@
+// Package server implements port forwarding for the SSH server.
+//
+// Security note: Port forwarding runs in the main server process without privilege separation.
+// The attack surface is primarily io.Copy through well-tested standard library code, making it
+// lower risk than shell execution which uses privilege-separated child processes. We enforce
+// user-level port restrictions: non-privileged users cannot bind to ports < 1024.
 package server
 
 import (
 	"encoding/binary"
 	"fmt"
-	"io"
 	"net"
+	"runtime"
 	"strconv"
 
 	"github.com/gliderlabs/ssh"
 	log "github.com/sirupsen/logrus"
 	cryptossh "golang.org/x/crypto/ssh"
+
+	nbssh "github.com/netbirdio/netbird/client/ssh"
 )
 
-// SessionKey uniquely identifies an SSH session
-type SessionKey string
+const privilegedPortThreshold = 1024
 
-// ConnectionKey uniquely identifies a port forwarding connection within a session
-type ConnectionKey string
+// sessionKey uniquely identifies an SSH session
+type sessionKey string
 
-// ForwardKey uniquely identifies a port forwarding listener
-type ForwardKey string
+// forwardKey uniquely identifies a port forwarding listener
+type forwardKey string
 
 // tcpipForwardMsg represents the structure for tcpip-forward SSH requests
 type tcpipForwardMsg struct {
@@ -47,34 +54,32 @@ func (s *Server) configurePortForwarding(server *ssh.Server) {
 	allowRemote := s.allowRemotePortForwarding
 
 	server.LocalPortForwardingCallback = func(ctx ssh.Context, dstHost string, dstPort uint32) bool {
+		logger := s.getRequestLogger(ctx)
 		if !allowLocal {
-			log.Warnf("local port forwarding denied for %s from %s: disabled by configuration",
-				net.JoinHostPort(dstHost, fmt.Sprintf("%d", dstPort)), ctx.RemoteAddr())
+			logger.Warnf("local port forwarding denied for %s:%d: disabled", dstHost, dstPort)
 			return false
 		}
 
 		if err := s.checkPortForwardingPrivileges(ctx, "local", dstPort); err != nil {
-			log.Warnf("local port forwarding denied for %s:%d from %s: %v", dstHost, dstPort, ctx.RemoteAddr(), err)
+			logger.Warnf("local port forwarding denied for %s:%d: %v", dstHost, dstPort, err)
 			return false
 		}
 
-		log.Debugf("local port forwarding allowed: %s:%d", dstHost, dstPort)
 		return true
 	}
 
 	server.ReversePortForwardingCallback = func(ctx ssh.Context, bindHost string, bindPort uint32) bool {
+		logger := s.getRequestLogger(ctx)
 		if !allowRemote {
-			log.Warnf("remote port forwarding denied for %s from %s: disabled by configuration",
-				net.JoinHostPort(bindHost, fmt.Sprintf("%d", bindPort)), ctx.RemoteAddr())
+			logger.Warnf("remote port forwarding denied for %s:%d: disabled", bindHost, bindPort)
 			return false
 		}
 
 		if err := s.checkPortForwardingPrivileges(ctx, "remote", bindPort); err != nil {
-			log.Warnf("remote port forwarding denied for %s:%d from %s: %v", bindHost, bindPort, ctx.RemoteAddr(), err)
+			logger.Warnf("remote port forwarding denied for %s:%d: %v", bindHost, bindPort, err)
 			return false
 		}
 
-		log.Debugf("remote port forwarding allowed: %s:%d", bindHost, bindPort)
 		return true
 	}
 
@@ -82,23 +87,20 @@ func (s *Server) configurePortForwarding(server *ssh.Server) {
 }
 
 // checkPortForwardingPrivileges validates privilege requirements for port forwarding operations.
-// Returns nil if allowed, error if denied.
+// For remote port forwarding (binding), it enforces that non-privileged users cannot bind to
+// ports below 1024, mirroring the restriction they would face if binding directly.
+//
+// Note: FeatureSupportsUserSwitch is true because we accept requests from any authenticated user,
+// though we don't actually switch users - port forwarding runs in the server process. The resolved
+// user is used for privileged port access checks.
 func (s *Server) checkPortForwardingPrivileges(ctx ssh.Context, forwardType string, port uint32) error {
 	if ctx == nil {
 		return fmt.Errorf("%s port forwarding denied: no context", forwardType)
 	}
 
-	username := ctx.User()
-	remoteAddr := "unknown"
-	if ctx.RemoteAddr() != nil {
-		remoteAddr = ctx.RemoteAddr().String()
-	}
-
-	logger := log.WithFields(log.Fields{"user": username, "remote": remoteAddr, "port": port})
-
 	result := s.CheckPrivileges(PrivilegeCheckRequest{
-		RequestedUsername:         username,
-		FeatureSupportsUserSwitch: false,
+		RequestedUsername:         ctx.User(),
+		FeatureSupportsUserSwitch: true,
 		FeatureName:               forwardType + " port forwarding",
 	})
 
@@ -106,12 +108,42 @@ func (s *Server) checkPortForwardingPrivileges(ctx ssh.Context, forwardType stri
 		return result.Error
 	}
 
-	logger.Debugf("%s port forwarding allowed: user %s validated (port %d)",
-		forwardType, result.User.Username, port)
+	if err := s.checkPrivilegedPortAccess(forwardType, port, result); err != nil {
+		return err
+	}
 
 	return nil
 }
 
+// checkPrivilegedPortAccess enforces that non-privileged users cannot bind to privileged ports.
+// This applies to remote port forwarding where the server binds a port on behalf of the user.
+// On Windows, there is no privileged port restriction, so this check is skipped.
+func (s *Server) checkPrivilegedPortAccess(forwardType string, port uint32, result PrivilegeCheckResult) error {
+	if runtime.GOOS == "windows" {
+		return nil
+	}
+
+	isBindOperation := forwardType == "remote" || forwardType == "tcpip-forward"
+	if !isBindOperation {
+		return nil
+	}
+
+	// Port 0 means "pick any available port", which will be >= 1024
+	if port == 0 || port >= privilegedPortThreshold {
+		return nil
+	}
+
+	if result.User != nil && isPrivilegedUsername(result.User.Username) {
+		return nil
+	}
+
+	username := "unknown"
+	if result.User != nil {
+		username = result.User.Username
+	}
+	return fmt.Errorf("user %s cannot bind to privileged port %d (requires root)", username, port)
+}
+
 // tcpipForwardHandler handles tcpip-forward requests for remote port forwarding.
 func (s *Server) tcpipForwardHandler(ctx ssh.Context, _ *ssh.Server, req *cryptossh.Request) (bool, []byte) {
 	logger := s.getRequestLogger(ctx)
@@ -132,8 +164,6 @@ func (s *Server) tcpipForwardHandler(ctx ssh.Context, _ *ssh.Server, req *crypto
 		return false, nil
 	}
 
-	logger.Debugf("tcpip-forward request: %s:%d", payload.Host, payload.Port)
-
 	sshConn, err := s.getSSHConnection(ctx)
 	if err != nil {
 		logger.Warnf("tcpip-forward request denied: %v", err)
@@ -153,8 +183,10 @@ func (s *Server) cancelTcpipForwardHandler(ctx ssh.Context, _ *ssh.Server, req *
 		return false, nil
 	}
 
-	key := ForwardKey(fmt.Sprintf("%s:%d", payload.Host, payload.Port))
+	key := forwardKey(fmt.Sprintf("%s:%d", payload.Host, payload.Port))
 	if s.removeRemoteForwardListener(key) {
+		forwardAddr := fmt.Sprintf("-R %s:%d", payload.Host, payload.Port)
+		s.removeConnectionPortForward(ctx.RemoteAddr(), forwardAddr)
 		logger.Infof("remote port forwarding cancelled: %s:%d", payload.Host, payload.Port)
 		return true, nil
 	}
@@ -165,14 +197,11 @@ func (s *Server) cancelTcpipForwardHandler(ctx ssh.Context, _ *ssh.Server, req *
 
 // handleRemoteForwardListener handles incoming connections for remote port forwarding.
 func (s *Server) handleRemoteForwardListener(ctx ssh.Context, ln net.Listener, host string, port uint32) {
-	log.Debugf("starting remote forward listener handler for %s:%d", host, port)
+	logger := s.getRequestLogger(ctx)
 
 	defer func() {
-		log.Debugf("cleaning up remote forward listener for %s:%d", host, port)
 		if err := ln.Close(); err != nil {
-			log.Debugf("remote forward listener close error: %v", err)
-		} else {
-			log.Debugf("remote forward listener closed successfully for %s:%d", host, port)
+			logger.Debugf("remote forward listener close error for %s:%d: %v", host, port, err)
 		}
 	}()
 
@@ -196,28 +225,43 @@ func (s *Server) handleRemoteForwardListener(ctx ssh.Context, ln net.Listener, h
 		select {
 		case result := <-acceptChan:
 			if result.err != nil {
-				log.Debugf("remote forward accept error: %v", result.err)
+				logger.Debugf("remote forward accept error: %v", result.err)
 				return
 			}
 			go s.handleRemoteForwardConnection(ctx, result.conn, host, port)
 		case <-ctx.Done():
-			log.Debugf("remote forward listener shutting down due to context cancellation for %s:%d", host, port)
+			logger.Debugf("remote forward listener shutting down for %s:%d", host, port)
 			return
 		}
 	}
 }
 
-// getRequestLogger creates a logger with user and remote address context
+// getRequestLogger creates a logger with session/conn and jwt_user context
 func (s *Server) getRequestLogger(ctx ssh.Context) *log.Entry {
-	remoteAddr := "unknown"
-	username := "unknown"
-	if ctx != nil {
-		if ctx.RemoteAddr() != nil {
-			remoteAddr = ctx.RemoteAddr().String()
+	sessionKey := s.findSessionKeyByContext(ctx)
+
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if state, exists := s.sessions[sessionKey]; exists {
+		logger := log.WithField("session", sessionKey)
+		if state.jwtUsername != "" {
+			logger = logger.WithField("jwt_user", state.jwtUsername)
 		}
-		username = ctx.User()
+		return logger
 	}
-	return log.WithFields(log.Fields{"user": username, "remote": remoteAddr})
+
+	if ctx.RemoteAddr() != nil {
+		if connState, exists := s.connections[connKey(ctx.RemoteAddr().String())]; exists {
+			return s.connLogger(connState)
+		}
+	}
+
+	remoteAddr := "unknown"
+	if ctx.RemoteAddr() != nil {
+		remoteAddr = ctx.RemoteAddr().String()
+	}
+	return log.WithField("session", fmt.Sprintf("%s@%s", ctx.User(), remoteAddr))
 }
 
 // isRemotePortForwardingAllowed checks if remote port forwarding is enabled
@@ -227,6 +271,13 @@ func (s *Server) isRemotePortForwardingAllowed() bool {
 	return s.allowRemotePortForwarding
 }
 
+// isPortForwardingEnabled checks if any port forwarding (local or remote) is enabled
+func (s *Server) isPortForwardingEnabled() bool {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.allowLocalPortForwarding || s.allowRemotePortForwarding
+}
+
 // parseTcpipForwardRequest parses the SSH request payload
 func (s *Server) parseTcpipForwardRequest(req *cryptossh.Request) (*tcpipForwardMsg, error) {
 	var payload tcpipForwardMsg
@@ -267,10 +318,11 @@ func (s *Server) setupDirectForward(ctx ssh.Context, logger *log.Entry, sshConn
 		logger.Debugf("tcpip-forward allocated port %d for %s", actualPort, payload.Host)
 	}
 
-	key := ForwardKey(fmt.Sprintf("%s:%d", payload.Host, payload.Port))
+	key := forwardKey(fmt.Sprintf("%s:%d", payload.Host, payload.Port))
 	s.storeRemoteForwardListener(key, ln)
 
-	s.markConnectionActivePortForward(sshConn, ctx.User(), ctx.RemoteAddr().String())
+	forwardAddr := fmt.Sprintf("-R %s:%d", payload.Host, actualPort)
+	s.addConnectionPortForward(ctx.User(), ctx.RemoteAddr(), forwardAddr)
 	go s.handleRemoteForwardListener(ctx, ln, payload.Host, actualPort)
 
 	response := make([]byte, 4)
@@ -288,44 +340,34 @@ type acceptResult struct {
 
 // handleRemoteForwardConnection handles a single remote port forwarding connection
 func (s *Server) handleRemoteForwardConnection(ctx ssh.Context, conn net.Conn, host string, port uint32) {
-	sessionKey := s.findSessionKeyByContext(ctx)
-	connID := fmt.Sprintf("pf-%s->%s:%d", conn.RemoteAddr(), host, port)
-	logger := log.WithFields(log.Fields{
-		"session": sessionKey,
-		"conn":    connID,
-	})
+	logger := s.getRequestLogger(ctx)
 
-	defer func() {
-		if err := conn.Close(); err != nil {
-			logger.Debugf("connection close error: %v", err)
-		}
-	}()
-
-	sshConn := ctx.Value(ssh.ContextKeyConn).(*cryptossh.ServerConn)
-	if sshConn == nil {
+	sshConn, ok := ctx.Value(ssh.ContextKeyConn).(*cryptossh.ServerConn)
+	if !ok || sshConn == nil {
 		logger.Debugf("remote forward: no SSH connection in context")
+		_ = conn.Close()
 		return
 	}
 
 	remoteAddr, ok := conn.RemoteAddr().(*net.TCPAddr)
 	if !ok {
 		logger.Warnf("remote forward: non-TCP connection type: %T", conn.RemoteAddr())
+		_ = conn.Close()
 		return
 	}
 
-	channel, err := s.openForwardChannel(sshConn, host, port, remoteAddr, logger)
+	channel, err := s.openForwardChannel(sshConn, host, port, remoteAddr)
 	if err != nil {
-		logger.Debugf("open forward channel: %v", err)
+		logger.Debugf("open forward channel for %s:%d: %v", host, port, err)
+		_ = conn.Close()
 		return
 	}
 
-	s.proxyForwardConnection(ctx, logger, conn, channel)
+	nbssh.BidirectionalCopyWithContext(logger, ctx, conn, channel)
 }
 
 // openForwardChannel creates an SSH forwarded-tcpip channel
-func (s *Server) openForwardChannel(sshConn *cryptossh.ServerConn, host string, port uint32, remoteAddr *net.TCPAddr, logger *log.Entry) (cryptossh.Channel, error) {
-	logger.Tracef("opening forwarded-tcpip channel for %s:%d", host, port)
-
+func (s *Server) openForwardChannel(sshConn *cryptossh.ServerConn, host string, port uint32, remoteAddr *net.TCPAddr) (cryptossh.Channel, error) {
 	payload := struct {
 		ConnectedAddress  string
 		ConnectedPort     uint32
@@ -346,41 +388,3 @@ func (s *Server) openForwardChannel(sshConn *cryptossh.ServerConn, host string,
 	go cryptossh.DiscardRequests(reqs)
 	return channel, nil
 }
-
-// proxyForwardConnection handles bidirectional data transfer between connection and SSH channel
-func (s *Server) proxyForwardConnection(ctx ssh.Context, logger *log.Entry, conn net.Conn, channel cryptossh.Channel) {
-	done := make(chan struct{}, 2)
-
-	go func() {
-		if _, err := io.Copy(channel, conn); err != nil {
-			logger.Debugf("copy error (conn->channel): %v", err)
-		}
-		done <- struct{}{}
-	}()
-
-	go func() {
-		if _, err := io.Copy(conn, channel); err != nil {
-			logger.Debugf("copy error (channel->conn): %v", err)
-		}
-		done <- struct{}{}
-	}()
-
-	select {
-	case <-ctx.Done():
-		logger.Debugf("session ended, closing connections")
-	case <-done:
-		// First copy finished, wait for second copy or context cancellation
-		select {
-		case <-ctx.Done():
-			logger.Debugf("session ended, closing connections")
-		case <-done:
-		}
-	}
-
-	if err := channel.Close(); err != nil {
-		logger.Debugf("channel close error: %v", err)
-	}
-	if err := conn.Close(); err != nil {
-		logger.Debugf("connection close error: %v", err)
-	}
-}

client/ssh/server/server.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"net/netip"
+	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -40,6 +41,11 @@ const (
 
 	msgPrivilegedUserDisabled = "privileged user login is disabled"
 
+	cmdInteractiveShell = "<interactive shell>"
+	cmdPortForwarding   = "<port forwarding>"
+	cmdSFTP             = "<sftp>"
+	cmdNonInteractive   = "<idle>"
+
 	// DefaultJWTMaxTokenAge is the default maximum age for JWT tokens accepted by the SSH server
 	DefaultJWTMaxTokenAge = 5 * 60
 )
@@ -90,10 +96,10 @@ func logSessionExitError(logger *log.Entry, err error) {
 	}
 }
 
-// safeLogCommand returns a safe representation of the command for logging
+// safeLogCommand returns a safe representation of the command for logging.
 func safeLogCommand(cmd []string) string {
 	if len(cmd) == 0 {
-		return "<interactive shell>"
+		return cmdInteractiveShell
 	}
 	if len(cmd) == 1 {
 		return cmd[0]
@@ -101,26 +107,50 @@ func safeLogCommand(cmd []string) string {
 	return fmt.Sprintf("%s [%d args]", cmd[0], len(cmd)-1)
 }
 
-type sshConnectionState struct {
-	hasActivePortForward bool
-	username             string
-	remoteAddr           string
+// connState tracks the state of an SSH connection for port forwarding and status display.
+type connState struct {
+	username     string
+	remoteAddr   net.Addr
+	portForwards []string
+	jwtUsername  string
 }
 
+// authKey uniquely identifies an authentication attempt by username and remote address.
+// Used to temporarily store JWT username between passwordHandler and sessionHandler.
 type authKey string
 
+// connKey uniquely identifies an SSH connection by its remote address.
+// Used to track authenticated connections for status display and port forwarding.
+type connKey string
+
 func newAuthKey(username string, remoteAddr net.Addr) authKey {
 	return authKey(fmt.Sprintf("%s@%s", username, remoteAddr.String()))
 }
 
+// sessionState tracks an active SSH session (shell, command, or subsystem like SFTP).
+type sessionState struct {
+	session     ssh.Session
+	sessionType string
+	jwtUsername string
+}
+
 type Server struct {
-	sshServer       *ssh.Server
-	mu              sync.RWMutex
-	hostKeyPEM      []byte
-	sessions        map[SessionKey]ssh.Session
-	sessionCancels  map[ConnectionKey]context.CancelFunc
-	sessionJWTUsers map[SessionKey]string
-	pendingAuthJWT  map[authKey]string
+	sshServer  *ssh.Server
+	mu         sync.RWMutex
+	hostKeyPEM []byte
+
+	// sessions tracks active SSH sessions (shell, command, SFTP).
+	// These are created when a client opens a session channel and requests shell/exec/subsystem.
+	sessions map[sessionKey]*sessionState
+
+	// pendingAuthJWT temporarily stores JWT username during the auth→session handoff.
+	// Populated in passwordHandler, consumed in sessionHandler/sftpSubsystemHandler.
+	pendingAuthJWT map[authKey]string
+
+	// connections tracks all SSH connections by their remote address.
+	// Populated at authentication time, stores JWT username and port forwards for status display.
+	connections map[connKey]*connState
+
 
 	allowLocalPortForwarding  bool
 	allowRemotePortForwarding bool
@@ -132,8 +162,7 @@ type Server struct {
 
 	wgAddress wgaddr.Address
 
-	remoteForwardListeners map[ForwardKey]net.Listener
-	sshConnections         map[*cryptossh.ServerConn]*sshConnectionState
+	remoteForwardListeners map[forwardKey]net.Listener
 
 	jwtValidator *jwt.Validator
 	jwtExtractor *jwt.ClaimsExtractor
@@ -167,6 +196,7 @@ type SessionInfo struct {
 	RemoteAddress string
 	Command       string
 	JWTUsername   string
+	PortForwards  []string
 }
 
 // New creates an SSH server instance with the provided host key and optional JWT configuration
@@ -175,11 +205,10 @@ func New(config *Config) *Server {
 	s := &Server{
 		mu:                     sync.RWMutex{},
 		hostKeyPEM:             config.HostKeyPEM,
-		sessions:               make(map[SessionKey]ssh.Session),
-		sessionJWTUsers:        make(map[SessionKey]string),
+		sessions:               make(map[sessionKey]*sessionState),
 		pendingAuthJWT:         make(map[authKey]string),
-		remoteForwardListeners: make(map[ForwardKey]net.Listener),
-		sshConnections:         make(map[*cryptossh.ServerConn]*sshConnectionState),
+		remoteForwardListeners: make(map[forwardKey]net.Listener),
+		connections:            make(map[connKey]*connState),
 		jwtEnabled:             config.JWT != nil,
 		jwtConfig:              config.JWT,
 		authorizer:             sshauth.NewAuthorizer(), // Initialize with empty config
@@ -265,14 +294,8 @@ func (s *Server) Stop() error {
 	s.sshServer = nil
 
 	maps.Clear(s.sessions)
-	maps.Clear(s.sessionJWTUsers)
 	maps.Clear(s.pendingAuthJWT)
-	maps.Clear(s.sshConnections)
-
-	for _, cancelFunc := range s.sessionCancels {
-		cancelFunc()
-	}
-	maps.Clear(s.sessionCancels)
+	maps.Clear(s.connections)
 
 	for _, listener := range s.remoteForwardListeners {
 		if err := listener.Close(); err != nil {
@@ -284,32 +307,70 @@ func (s *Server) Stop() error {
 	return nil
 }
 
-// GetStatus returns the current status of the SSH server and active sessions
+// GetStatus returns the current status of the SSH server and active sessions.
 func (s *Server) GetStatus() (enabled bool, sessions []SessionInfo) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
 	enabled = s.sshServer != nil
+	reportedAddrs := make(map[string]bool)
 
-	for sessionKey, session := range s.sessions {
-		cmd := "<interactive shell>"
-		if len(session.Command()) > 0 {
-			cmd = safeLogCommand(session.Command())
+	for _, state := range s.sessions {
+		info := s.buildSessionInfo(state)
+		reportedAddrs[info.RemoteAddress] = true
+		sessions = append(sessions, info)
+	}
+
+	// Add authenticated connections without sessions (e.g., -N/-T or port-forwarding only)
+	for key, connState := range s.connections {
+		remoteAddr := string(key)
+		if reportedAddrs[remoteAddr] {
+			continue
+		}
+		cmd := cmdNonInteractive
+		if len(connState.portForwards) > 0 {
+			cmd = cmdPortForwarding
 		}
-
-		jwtUsername := s.sessionJWTUsers[sessionKey]
-
 		sessions = append(sessions, SessionInfo{
-			Username:      session.User(),
-			RemoteAddress: session.RemoteAddr().String(),
+			Username:      connState.username,
+			RemoteAddress: remoteAddr,
 			Command:       cmd,
-			JWTUsername:   jwtUsername,
+			JWTUsername:   connState.jwtUsername,
+			PortForwards:  connState.portForwards,
 		})
 	}
 
 	return enabled, sessions
 }
 
+func (s *Server) buildSessionInfo(state *sessionState) SessionInfo {
+	session := state.session
+	cmd := state.sessionType
+	if cmd == "" {
+		cmd = safeLogCommand(session.Command())
+	}
+
+	remoteAddr := session.RemoteAddr().String()
+	info := SessionInfo{
+		Username:      session.User(),
+		RemoteAddress: remoteAddr,
+		Command:       cmd,
+		JWTUsername:   state.jwtUsername,
+	}
+
+	connState, exists := s.connections[connKey(remoteAddr)]
+	if !exists {
+		return info
+	}
+
+	info.PortForwards = connState.portForwards
+	if len(connState.portForwards) > 0 && (cmd == cmdInteractiveShell || cmd == cmdNonInteractive) {
+		info.Command = cmdPortForwarding
+	}
+
+	return info
+}
+
 // SetNetstackNet sets the netstack network for userspace networking
 func (s *Server) SetNetstackNet(net *netstack.Net) {
 	s.mu.Lock()
@@ -520,69 +581,129 @@ func (s *Server) parseTokenWithoutValidation(tokenString string) (map[string]int
 func (s *Server) passwordHandler(ctx ssh.Context, password string) bool {
 	osUsername := ctx.User()
 	remoteAddr := ctx.RemoteAddr()
+	logger := s.getRequestLogger(ctx)
 
 	if err := s.ensureJWTValidator(); err != nil {
-		log.Errorf("JWT validator initialization failed for user %s from %s: %v", osUsername, remoteAddr, err)
+		logger.Errorf("JWT validator initialization failed: %v", err)
 		return false
 	}
 
 	token, err := s.validateJWTToken(password)
 	if err != nil {
-		log.Warnf("JWT authentication failed for user %s from %s: %v", osUsername, remoteAddr, err)
+		logger.Warnf("JWT authentication failed: %v", err)
 		return false
 	}
 
 	userAuth, err := s.extractAndValidateUser(token)
 	if err != nil {
-		log.Warnf("User validation failed for user %s from %s: %v", osUsername, remoteAddr, err)
+		logger.Warnf("user validation failed: %v", err)
 		return false
 	}
 
+	logger = logger.WithField("jwt_user", userAuth.UserId)
+
 	s.mu.RLock()
 	authorizer := s.authorizer
 	s.mu.RUnlock()
 
-	if err := authorizer.Authorize(userAuth.UserId, osUsername); err != nil {
-		log.Warnf("SSH authorization denied for user %s (JWT user ID: %s) from %s: %v", osUsername, userAuth.UserId, remoteAddr, err)
+	msg, err := authorizer.Authorize(userAuth.UserId, osUsername)
+	if err != nil {
+		logger.Warnf("SSH auth denied: %v", err)
 		return false
 	}
 
+	logger.Infof("SSH auth %s", msg)
+
 	key := newAuthKey(osUsername, remoteAddr)
+	remoteAddrStr := ctx.RemoteAddr().String()
 	s.mu.Lock()
 	s.pendingAuthJWT[key] = userAuth.UserId
+	s.connections[connKey(remoteAddrStr)] = &connState{
+		username:    ctx.User(),
+		remoteAddr:  ctx.RemoteAddr(),
+		jwtUsername: userAuth.UserId,
+	}
 	s.mu.Unlock()
 
-	log.Infof("JWT authentication successful for user %s (JWT user ID: %s) from %s", osUsername, userAuth.UserId, remoteAddr)
 	return true
 }
 
-func (s *Server) markConnectionActivePortForward(sshConn *cryptossh.ServerConn, username, remoteAddr string) {
+func (s *Server) addConnectionPortForward(username string, remoteAddr net.Addr, forwardAddr string) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	if state, exists := s.sshConnections[sshConn]; exists {
-		state.hasActivePortForward = true
-	} else {
-		s.sshConnections[sshConn] = &sshConnectionState{
-			hasActivePortForward: true,
-			username:             username,
-			remoteAddr:           remoteAddr,
+	key := connKey(remoteAddr.String())
+	if state, exists := s.connections[key]; exists {
+		if !slices.Contains(state.portForwards, forwardAddr) {
+			state.portForwards = append(state.portForwards, forwardAddr)
 		}
+		return
+	}
+
+	// Connection not in connections (non-JWT auth path)
+	s.connections[key] = &connState{
+		username:     username,
+		remoteAddr:   remoteAddr,
+		portForwards: []string{forwardAddr},
+		jwtUsername:  s.pendingAuthJWT[newAuthKey(username, remoteAddr)],
 	}
 }
 
-func (s *Server) connectionCloseHandler(conn net.Conn, err error) {
-	// We can't extract the SSH connection from net.Conn directly
-	// Connection cleanup will happen during session cleanup or via timeout
-	log.Debugf("SSH connection failed for %s: %v", conn.RemoteAddr(), err)
+func (s *Server) removeConnectionPortForward(remoteAddr net.Addr, forwardAddr string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	state, exists := s.connections[connKey(remoteAddr.String())]
+	if !exists {
+		return
+	}
+
+	state.portForwards = slices.DeleteFunc(state.portForwards, func(addr string) bool {
+		return addr == forwardAddr
+	})
 }
 
-func (s *Server) findSessionKeyByContext(ctx ssh.Context) SessionKey {
+// trackedConn wraps a net.Conn to detect when it closes
+type trackedConn struct {
+	net.Conn
+	server     *Server
+	remoteAddr string
+	onceClose  sync.Once
+}
+
+func (c *trackedConn) Close() error {
+	err := c.Conn.Close()
+	c.onceClose.Do(func() {
+		c.server.handleConnectionClose(c.remoteAddr)
+	})
+	return err
+}
+
+func (s *Server) handleConnectionClose(remoteAddr string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	key := connKey(remoteAddr)
+	state, exists := s.connections[key]
+	if exists && len(state.portForwards) > 0 {
+		s.connLogger(state).Info("port forwarding connection closed")
+	}
+	delete(s.connections, key)
+}
+
+func (s *Server) connLogger(state *connState) *log.Entry {
+	logger := log.WithField("session", fmt.Sprintf("%s@%s", state.username, state.remoteAddr))
+	if state.jwtUsername != "" {
+		logger = logger.WithField("jwt_user", state.jwtUsername)
+	}
+	return logger
+}
+
+func (s *Server) findSessionKeyByContext(ctx ssh.Context) sessionKey {
 	if ctx == nil {
 		return "unknown"
 	}
 
-	// Try to match by SSH connection
 	sshConn := ctx.Value(ssh.ContextKeyConn)
 	if sshConn == nil {
 		return "unknown"
@@ -591,19 +712,14 @@ func (s *Server) findSessionKeyByContext(ctx ssh.Context) SessionKey {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	// Look through sessions to find one with matching connection
-	for sessionKey, session := range s.sessions {
-		if session.Context().Value(ssh.ContextKeyConn) == sshConn {
+	for sessionKey, state := range s.sessions {
+		if state.session.Context().Value(ssh.ContextKeyConn) == sshConn {
 			return sessionKey
 		}
 	}
 
-	// If no session found, this might be during early connection setup
-	// Return a temporary key that we'll fix up later
 	if ctx.User() != "" && ctx.RemoteAddr() != nil {
-		tempKey := SessionKey(fmt.Sprintf("%s@%s", ctx.User(), ctx.RemoteAddr().String()))
-		log.Debugf("Using temporary session key for early port forward tracking: %s (will be updated when session established)", tempKey)
-		return tempKey
+		return sessionKey(fmt.Sprintf("%s@%s", ctx.User(), ctx.RemoteAddr().String()))
 	}
 
 	return "unknown"
@@ -644,7 +760,11 @@ func (s *Server) connectionValidator(_ ssh.Context, conn net.Conn) net.Conn {
 	}
 
 	log.Infof("SSH connection from NetBird peer %s allowed", tcpAddr)
-	return conn
+	return &trackedConn{
+		Conn:       conn,
+		server:     s,
+		remoteAddr: conn.RemoteAddr().String(),
+	}
 }
 
 func (s *Server) createSSHServer(addr net.Addr) (*ssh.Server, error) {
@@ -672,9 +792,8 @@ func (s *Server) createSSHServer(addr net.Addr) (*ssh.Server, error) {
 			"tcpip-forward":        s.tcpipForwardHandler,
 			"cancel-tcpip-forward": s.cancelTcpipForwardHandler,
 		},
-		ConnCallback:             s.connectionValidator,
-		ConnectionFailedCallback: s.connectionCloseHandler,
-		Version:                  serverVersion,
+		ConnCallback: s.connectionValidator,
+		Version:      serverVersion,
 	}
 
 	if s.jwtEnabled {
@@ -690,13 +809,13 @@ func (s *Server) createSSHServer(addr net.Addr) (*ssh.Server, error) {
 	return server, nil
 }
 
-func (s *Server) storeRemoteForwardListener(key ForwardKey, ln net.Listener) {
+func (s *Server) storeRemoteForwardListener(key forwardKey, ln net.Listener) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.remoteForwardListeners[key] = ln
 }
 
-func (s *Server) removeRemoteForwardListener(key ForwardKey) bool {
+func (s *Server) removeRemoteForwardListener(key forwardKey) bool {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
@@ -714,6 +833,8 @@ func (s *Server) removeRemoteForwardListener(key ForwardKey) bool {
 }
 
 func (s *Server) directTCPIPHandler(srv *ssh.Server, conn *cryptossh.ServerConn, newChan cryptossh.NewChannel, ctx ssh.Context) {
+	logger := s.getRequestLogger(ctx)
+
 	var payload struct {
 		Host           string
 		Port           uint32
@@ -723,7 +844,7 @@ func (s *Server) directTCPIPHandler(srv *ssh.Server, conn *cryptossh.ServerConn,
 
 	if err := cryptossh.Unmarshal(newChan.ExtraData(), &payload); err != nil {
 		if err := newChan.Reject(cryptossh.ConnectionFailed, "parse payload"); err != nil {
-			log.Debugf("channel reject error: %v", err)
+			logger.Debugf("channel reject error: %v", err)
 		}
 		return
 	}
@@ -733,19 +854,20 @@ func (s *Server) directTCPIPHandler(srv *ssh.Server, conn *cryptossh.ServerConn,
 	s.mu.RUnlock()
 
 	if !allowLocal {
-		log.Warnf("local port forwarding denied for %s:%d: disabled by configuration", payload.Host, payload.Port)
+		logger.Warnf("local port forwarding denied for %s:%d: disabled", payload.Host, payload.Port)
 		_ = newChan.Reject(cryptossh.Prohibited, "local port forwarding disabled")
 		return
 	}
 
-	// Check privilege requirements for the destination port
 	if err := s.checkPortForwardingPrivileges(ctx, "local", payload.Port); err != nil {
-		log.Warnf("local port forwarding denied for %s:%d: %v", payload.Host, payload.Port, err)
+		logger.Warnf("local port forwarding denied for %s:%d: %v", payload.Host, payload.Port, err)
 		_ = newChan.Reject(cryptossh.Prohibited, "insufficient privileges")
 		return
 	}
 
-	log.Infof("local port forwarding: %s:%d", payload.Host, payload.Port)
+	forwardAddr := fmt.Sprintf("-L %s:%d", payload.Host, payload.Port)
+	s.addConnectionPortForward(ctx.User(), ctx.RemoteAddr(), forwardAddr)
+	logger.Infof("local port forwarding: %s:%d", payload.Host, payload.Port)
 
 	ssh.DirectTCPIPHandler(srv, conn, newChan, ctx)
 }

client/ssh/server/server_config_test.go

@@ -224,6 +224,96 @@ func TestServer_PortForwardingRestriction(t *testing.T) {
 	}
 }
 
+func TestServer_PrivilegedPortAccess(t *testing.T) {
+	hostKey, err := ssh.GeneratePrivateKey(ssh.ED25519)
+	require.NoError(t, err)
+
+	serverConfig := &Config{
+		HostKeyPEM: hostKey,
+	}
+	server := New(serverConfig)
+	server.SetAllowRemotePortForwarding(true)
+
+	tests := []struct {
+		name          string
+		forwardType   string
+		port          uint32
+		username      string
+		expectError   bool
+		errorMsg      string
+		skipOnWindows bool
+	}{
+		{
+			name:          "non-root user remote forward privileged port",
+			forwardType:   "remote",
+			port:          80,
+			username:      "testuser",
+			expectError:   true,
+			errorMsg:      "cannot bind to privileged port",
+			skipOnWindows: true,
+		},
+		{
+			name:          "non-root user tcpip-forward privileged port",
+			forwardType:   "tcpip-forward",
+			port:          443,
+			username:      "testuser",
+			expectError:   true,
+			errorMsg:      "cannot bind to privileged port",
+			skipOnWindows: true,
+		},
+		{
+			name:        "non-root user remote forward unprivileged port",
+			forwardType: "remote",
+			port:        8080,
+			username:    "testuser",
+			expectError: false,
+		},
+		{
+			name:        "non-root user remote forward port 0",
+			forwardType: "remote",
+			port:        0,
+			username:    "testuser",
+			expectError: false,
+		},
+		{
+			name:        "root user remote forward privileged port",
+			forwardType: "remote",
+			port:        22,
+			username:    "root",
+			expectError: false,
+		},
+		{
+			name:        "local forward privileged port allowed for non-root",
+			forwardType: "local",
+			port:        80,
+			username:    "testuser",
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.skipOnWindows && runtime.GOOS == "windows" {
+				t.Skip("Windows does not have privileged port restrictions")
+			}
+
+			result := PrivilegeCheckResult{
+				Allowed: true,
+				User:    &user.User{Username: tt.username},
+			}
+
+			err := server.checkPrivilegedPortAccess(tt.forwardType, tt.port, result)
+
+			if tt.expectError {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), tt.errorMsg)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
 func TestServer_PortConflictHandling(t *testing.T) {
 	// Test that multiple sessions requesting the same local port are handled naturally by the OS
 	// Get current user for SSH connection
@@ -392,3 +482,95 @@ func TestServer_IsPrivilegedUser(t *testing.T) {
 		})
 	}
 }
+
+func TestServer_PortForwardingOnlySession(t *testing.T) {
+	// Test that sessions without PTY and command are allowed when port forwarding is enabled
+	currentUser, err := user.Current()
+	require.NoError(t, err, "Should be able to get current user")
+
+	// Generate host key for server
+	hostKey, err := ssh.GeneratePrivateKey(ssh.ED25519)
+	require.NoError(t, err)
+
+	tests := []struct {
+		name                  string
+		allowLocalForwarding  bool
+		allowRemoteForwarding bool
+		expectAllowed         bool
+		description           string
+	}{
+		{
+			name:                  "session_allowed_with_local_forwarding",
+			allowLocalForwarding:  true,
+			allowRemoteForwarding: false,
+			expectAllowed:         true,
+			description:           "Port-forwarding-only session should be allowed when local forwarding is enabled",
+		},
+		{
+			name:                  "session_allowed_with_remote_forwarding",
+			allowLocalForwarding:  false,
+			allowRemoteForwarding: true,
+			expectAllowed:         true,
+			description:           "Port-forwarding-only session should be allowed when remote forwarding is enabled",
+		},
+		{
+			name:                  "session_allowed_with_both",
+			allowLocalForwarding:  true,
+			allowRemoteForwarding: true,
+			expectAllowed:         true,
+			description:           "Port-forwarding-only session should be allowed when both forwarding types enabled",
+		},
+		{
+			name:                  "session_denied_without_forwarding",
+			allowLocalForwarding:  false,
+			allowRemoteForwarding: false,
+			expectAllowed:         false,
+			description:           "Port-forwarding-only session should be denied when all forwarding is disabled",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			serverConfig := &Config{
+				HostKeyPEM: hostKey,
+				JWT:        nil,
+			}
+			server := New(serverConfig)
+			server.SetAllowRootLogin(true)
+			server.SetAllowLocalPortForwarding(tt.allowLocalForwarding)
+			server.SetAllowRemotePortForwarding(tt.allowRemoteForwarding)
+
+			serverAddr := StartTestServer(t, server)
+			defer func() {
+				_ = server.Stop()
+			}()
+
+			// Connect to the server without requesting PTY or command
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+
+			client, err := sshclient.Dial(ctx, serverAddr, currentUser.Username, sshclient.DialOptions{
+				InsecureSkipVerify: true,
+			})
+			require.NoError(t, err)
+			defer func() {
+				_ = client.Close()
+			}()
+
+			// Execute a command without PTY - this simulates ssh -T with no command
+			// The server should either allow it (port forwarding enabled) or reject it
+			output, err := client.ExecuteCommand(ctx, "")
+			if tt.expectAllowed {
+				// When allowed, the session stays open until cancelled
+				// ExecuteCommand with empty command should return without error
+				assert.NoError(t, err, "Session should be allowed when port forwarding is enabled")
+				assert.NotContains(t, output, "port forwarding is disabled",
+					"Output should not contain port forwarding disabled message")
+			} else if err != nil {
+				// When denied, we expect an error message about port forwarding being disabled
+				assert.Contains(t, err.Error(), "port forwarding is disabled",
+					"Should get port forwarding disabled message")
+			}
+		})
+	}
+}

client/ssh/server/session_handlers.go

@@ -6,37 +6,45 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"strings"
 	"time"
 
 	"github.com/gliderlabs/ssh"
 	log "github.com/sirupsen/logrus"
-	cryptossh "golang.org/x/crypto/ssh"
 )
 
+// associateJWTUsername extracts pending JWT username for the session and associates it with the session state.
+// Returns the JWT username (empty if none) for logging purposes.
+func (s *Server) associateJWTUsername(sess ssh.Session, sessionKey sessionKey) string {
+	key := newAuthKey(sess.User(), sess.RemoteAddr())
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	jwtUsername := s.pendingAuthJWT[key]
+	if jwtUsername == "" {
+		return ""
+	}
+
+	if state, exists := s.sessions[sessionKey]; exists {
+		state.jwtUsername = jwtUsername
+	}
+	delete(s.pendingAuthJWT, key)
+	return jwtUsername
+}
+
 // sessionHandler handles SSH sessions
 func (s *Server) sessionHandler(session ssh.Session) {
-	sessionKey := s.registerSession(session)
-
-	key := newAuthKey(session.User(), session.RemoteAddr())
-	s.mu.Lock()
-	jwtUsername := s.pendingAuthJWT[key]
-	if jwtUsername != "" {
-		s.sessionJWTUsers[sessionKey] = jwtUsername
-		delete(s.pendingAuthJWT, key)
-	}
-	s.mu.Unlock()
+	sessionKey := s.registerSession(session, "")
+	jwtUsername := s.associateJWTUsername(session, sessionKey)
 
 	logger := log.WithField("session", sessionKey)
 	if jwtUsername != "" {
 		logger = logger.WithField("jwt_user", jwtUsername)
-		logger.Infof("SSH session started (JWT user: %s)", jwtUsername)
-	} else {
-		logger.Infof("SSH session started")
 	}
+	logger.Info("SSH session started")
 	sessionStart := time.Now()
 
-	defer s.unregisterSession(sessionKey, session)
+	defer s.unregisterSession(sessionKey)
 	defer func() {
 		duration := time.Since(sessionStart).Round(time.Millisecond)
 		if err := session.Close(); err != nil && !errors.Is(err, io.EOF) {
@@ -65,27 +73,52 @@ func (s *Server) sessionHandler(session ssh.Session) {
 		// ssh <host> <cmd> - non-Pty command execution
 		s.handleCommand(logger, session, privilegeResult, nil)
 	default:
-		s.rejectInvalidSession(logger, session)
+		// ssh -T (or ssh -N) - no PTY, no command
+		s.handleNonInteractiveSession(logger, session)
 	}
 }
 
-func (s *Server) rejectInvalidSession(logger *log.Entry, session ssh.Session) {
-	if _, err := io.WriteString(session, "no command specified and Pty not requested\n"); err != nil {
-		logger.Debugf(errWriteSession, err)
+// handleNonInteractiveSession handles sessions that have no PTY and no command.
+// These are typically used for port forwarding (ssh -L/-R) or tunneling (ssh -N).
+func (s *Server) handleNonInteractiveSession(logger *log.Entry, session ssh.Session) {
+	s.updateSessionType(session, cmdNonInteractive)
+
+	if !s.isPortForwardingEnabled() {
+		if _, err := io.WriteString(session, "port forwarding is disabled on this server\n"); err != nil {
+			logger.Debugf(errWriteSession, err)
+		}
+		if err := session.Exit(1); err != nil {
+			logSessionExitError(logger, err)
+		}
+		logger.Infof("rejected non-interactive session: port forwarding disabled")
+		return
 	}
-	if err := session.Exit(1); err != nil {
+
+	<-session.Context().Done()
+
+	if err := session.Exit(0); err != nil {
 		logSessionExitError(logger, err)
 	}
-	logger.Infof("rejected non-Pty session without command from %s", session.RemoteAddr())
 }
 
-func (s *Server) registerSession(session ssh.Session) SessionKey {
+func (s *Server) updateSessionType(session ssh.Session, sessionType string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	for _, state := range s.sessions {
+		if state.session == session {
+			state.sessionType = sessionType
+			return
+		}
+	}
+}
+
+func (s *Server) registerSession(session ssh.Session, sessionType string) sessionKey {
 	sessionID := session.Context().Value(ssh.ContextKeySessionID)
 	if sessionID == nil {
 		sessionID = fmt.Sprintf("%p", session)
 	}
 
-	// Create a short 4-byte identifier from the full session ID
 	hasher := sha256.New()
 	hasher.Write([]byte(fmt.Sprintf("%v", sessionID)))
 	hash := hasher.Sum(nil)
@@ -93,43 +126,23 @@ func (s *Server) registerSession(session ssh.Session) SessionKey {
 
 	remoteAddr := session.RemoteAddr().String()
 	username := session.User()
-	sessionKey := SessionKey(fmt.Sprintf("%s@%s-%s", username, remoteAddr, shortID))
+	sessionKey := sessionKey(fmt.Sprintf("%s@%s-%s", username, remoteAddr, shortID))
 
 	s.mu.Lock()
-	s.sessions[sessionKey] = session
+	s.sessions[sessionKey] = &sessionState{
+		session:     session,
+		sessionType: sessionType,
+	}
 	s.mu.Unlock()
 
 	return sessionKey
 }
 
-func (s *Server) unregisterSession(sessionKey SessionKey, session ssh.Session) {
+func (s *Server) unregisterSession(sessionKey sessionKey) {
 	s.mu.Lock()
+	defer s.mu.Unlock()
+
 	delete(s.sessions, sessionKey)
-	delete(s.sessionJWTUsers, sessionKey)
-
-	// Cancel all port forwarding connections for this session
-	var connectionsToCancel []ConnectionKey
-	for key := range s.sessionCancels {
-		if strings.HasPrefix(string(key), string(sessionKey)+"-") {
-			connectionsToCancel = append(connectionsToCancel, key)
-		}
-	}
-
-	for _, key := range connectionsToCancel {
-		if cancelFunc, exists := s.sessionCancels[key]; exists {
-			log.WithField("session", sessionKey).Debugf("cancelling port forwarding context: %s", key)
-			cancelFunc()
-			delete(s.sessionCancels, key)
-		}
-	}
-
-	if sshConnValue := session.Context().Value(ssh.ContextKeyConn); sshConnValue != nil {
-		if sshConn, ok := sshConnValue.(*cryptossh.ServerConn); ok {
-			delete(s.sshConnections, sshConn)
-		}
-	}
-
-	s.mu.Unlock()
 }
 
 func (s *Server) handlePrivError(logger *log.Entry, session ssh.Session, err error) {

client/ssh/server/sftp.go

@@ -18,14 +18,26 @@ func (s *Server) SetAllowSFTP(allow bool) {
 
 // sftpSubsystemHandler handles SFTP subsystem requests
 func (s *Server) sftpSubsystemHandler(sess ssh.Session) {
+	sessionKey := s.registerSession(sess, cmdSFTP)
+	defer s.unregisterSession(sessionKey)
+
+	jwtUsername := s.associateJWTUsername(sess, sessionKey)
+
+	logger := log.WithField("session", sessionKey)
+	if jwtUsername != "" {
+		logger = logger.WithField("jwt_user", jwtUsername)
+	}
+	logger.Info("SFTP session started")
+	defer logger.Info("SFTP session closed")
+
 	s.mu.RLock()
 	allowSFTP := s.allowSFTP
 	s.mu.RUnlock()
 
 	if !allowSFTP {
-		log.Debugf("SFTP subsystem request denied: SFTP disabled")
+		logger.Debug("SFTP subsystem request denied: SFTP disabled")
 		if err := sess.Exit(1); err != nil {
-			log.Debugf("SFTP session exit failed: %v", err)
+			logger.Debugf("SFTP session exit: %v", err)
 		}
 		return
 	}
@@ -37,31 +49,27 @@ func (s *Server) sftpSubsystemHandler(sess ssh.Session) {
 	})
 
 	if !result.Allowed {
-		log.Warnf("SFTP access denied for user %s from %s: %v", sess.User(), sess.RemoteAddr(), result.Error)
+		logger.Warnf("SFTP access denied: %v", result.Error)
 		if err := sess.Exit(1); err != nil {
-			log.Debugf("exit SFTP session: %v", err)
+			logger.Debugf("exit SFTP session: %v", err)
 		}
 		return
 	}
 
-	log.Debugf("SFTP subsystem request from user %s (effective user %s)", sess.User(), result.User.Username)
-
 	if !result.RequiresUserSwitching {
 		if err := s.executeSftpDirect(sess); err != nil {
-			log.Errorf("SFTP direct execution: %v", err)
+			logger.Errorf("SFTP direct execution: %v", err)
 		}
 		return
 	}
 
 	if err := s.executeSftpWithPrivilegeDrop(sess, result.User); err != nil {
-		log.Errorf("SFTP privilege drop execution: %v", err)
+		logger.Errorf("SFTP privilege drop execution: %v", err)
 	}
 }
 
 // executeSftpDirect executes SFTP directly without privilege dropping
 func (s *Server) executeSftpDirect(sess ssh.Session) error {
-	log.Debugf("starting SFTP session for user %s (no privilege dropping)", sess.User())
-
 	sftpServer, err := sftp.NewServer(sess)
 	if err != nil {
 		return fmt.Errorf("SFTP server creation: %w", err)