[client] Open browser for ssh automatically (#4838)

client/cmd/login.go

@@ -4,14 +4,12 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"os/exec"
 	"os/user"
 	"runtime"
 	"strings"
 	"time"
 
 	log "github.com/sirupsen/logrus"
-	"github.com/skratchdot/open-golang/open"
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
@@ -373,21 +371,13 @@ func openURL(cmd *cobra.Command, verificationURIComplete, userCode string, noBro
 	cmd.Println("")
 
 	if !noBrowser {
-		if err := openBrowser(verificationURIComplete); err != nil {
+		if err := util.OpenBrowser(verificationURIComplete); err != nil {
 			cmd.Println("\nAlternatively, you may want to use a setup key, see:\n\n" +
 				"https://docs.netbird.io/how-to/register-machines-using-setup-keys")
 		}
 	}
 }
 
-// openBrowser opens the URL in a browser, respecting the BROWSER environment variable.
-func openBrowser(url string) error {
-	if browser := os.Getenv("BROWSER"); browser != "" {
-		return exec.Command(browser, url).Start()
-	}
-	return open.Run(url)
-}
-
 // isUnixRunningDesktop checks if a Linux OS is running desktop environment
 func isUnixRunningDesktop() bool {
 	if runtime.GOOS != "linux" && runtime.GOOS != "freebsd" {

client/cmd/ssh.go

@@ -51,6 +51,7 @@ var (
 	identityFile          string
 	skipCachedToken       bool
 	requestPTY            bool
+	sshNoBrowser          bool
 )
 
 var (
@@ -81,6 +82,7 @@ func init() {
 	sshCmd.PersistentFlags().StringVarP(&identityFile, "identity", "i", "", "Path to SSH private key file (deprecated)")
 	_ = sshCmd.PersistentFlags().MarkDeprecated("identity", "this flag is no longer used")
 	sshCmd.PersistentFlags().BoolVar(&skipCachedToken, "no-cache", false, "Skip cached JWT token and force fresh authentication")
+	sshCmd.PersistentFlags().BoolVar(&sshNoBrowser, noBrowserFlag, false, noBrowserDesc)
 
 	sshCmd.PersistentFlags().StringArrayP("L", "L", []string{}, "Local port forwarding [bind_address:]port:host:hostport")
 	sshCmd.PersistentFlags().StringArrayP("R", "R", []string{}, "Remote port forwarding [bind_address:]port:host:hostport")
@@ -185,6 +187,21 @@ func getEnvOrDefault(flagName, defaultValue string) string {
 	return defaultValue
 }
 
+// getBoolEnvOrDefault checks for boolean environment variables with WT_ and NB_ prefixes
+func getBoolEnvOrDefault(flagName string, defaultValue bool) bool {
+	if envValue := os.Getenv("WT_" + flagName); envValue != "" {
+		if parsed, err := strconv.ParseBool(envValue); err == nil {
+			return parsed
+		}
+	}
+	if envValue := os.Getenv("NB_" + flagName); envValue != "" {
+		if parsed, err := strconv.ParseBool(envValue); err == nil {
+			return parsed
+		}
+	}
+	return defaultValue
+}
+
 // resetSSHGlobals sets SSH globals to their default values
 func resetSSHGlobals() {
 	port = sshserver.DefaultSSHPort
@@ -196,6 +213,7 @@ func resetSSHGlobals() {
 	strictHostKeyChecking = true
 	knownHostsFile = ""
 	identityFile = ""
+	sshNoBrowser = false
 }
 
 // parseCustomSSHFlags extracts -L, -R flags and returns filtered args
@@ -370,6 +388,7 @@ type sshFlags struct {
 	KnownHostsFile        string
 	IdentityFile          string
 	SkipCachedToken       bool
+	NoBrowser             bool
 	ConfigPath            string
 	LogLevel              string
 	LocalForwards         []string
@@ -381,6 +400,7 @@ type sshFlags struct {
 func createSSHFlagSet() (*flag.FlagSet, *sshFlags) {
 	defaultConfigPath := getEnvOrDefault("CONFIG", configPath)
 	defaultLogLevel := getEnvOrDefault("LOG_LEVEL", logLevel)
+	defaultNoBrowser := getBoolEnvOrDefault("NO_BROWSER", false)
 
 	fs := flag.NewFlagSet("ssh-flags", flag.ContinueOnError)
 	fs.SetOutput(nil)
@@ -401,6 +421,7 @@ func createSSHFlagSet() (*flag.FlagSet, *sshFlags) {
 	fs.StringVar(&flags.IdentityFile, "i", "", "Path to SSH private key file")
 	fs.StringVar(&flags.IdentityFile, "identity", "", "Path to SSH private key file")
 	fs.BoolVar(&flags.SkipCachedToken, "no-cache", false, "Skip cached JWT token and force fresh authentication")
+	fs.BoolVar(&flags.NoBrowser, "no-browser", defaultNoBrowser, noBrowserDesc)
 
 	fs.StringVar(&flags.ConfigPath, "c", defaultConfigPath, "Netbird config file location")
 	fs.StringVar(&flags.ConfigPath, "config", defaultConfigPath, "Netbird config file location")
@@ -449,6 +470,7 @@ func validateSSHArgsWithoutFlagParsing(_ *cobra.Command, args []string) error {
 	knownHostsFile = flags.KnownHostsFile
 	identityFile = flags.IdentityFile
 	skipCachedToken = flags.SkipCachedToken
+	sshNoBrowser = flags.NoBrowser
 
 	if flags.ConfigPath != getEnvOrDefault("CONFIG", configPath) {
 		configPath = flags.ConfigPath
@@ -508,6 +530,7 @@ func runSSH(ctx context.Context, addr string, cmd *cobra.Command) error {
 		DaemonAddr:         daemonAddr,
 		SkipCachedToken:    skipCachedToken,
 		InsecureSkipVerify: !strictHostKeyChecking,
+		NoBrowser:          sshNoBrowser,
 	})
 
 	if err != nil {
@@ -763,7 +786,15 @@ func sshProxyFn(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("invalid port: %s", portStr)
 	}
 
-	proxy, err := sshproxy.New(daemonAddr, host, port, cmd.ErrOrStderr())
+	// Check env var for browser setting since this command is invoked via SSH ProxyCommand
+	// where command-line flags cannot be passed. Default is to open browser.
+	noBrowser := getBoolEnvOrDefault("NO_BROWSER", false)
+	var browserOpener func(string) error
+	if !noBrowser {
+		browserOpener = util.OpenBrowser
+	}
+
+	proxy, err := sshproxy.New(daemonAddr, host, port, cmd.ErrOrStderr(), browserOpener)
 	if err != nil {
 		return fmt.Errorf("create SSH proxy: %w", err)
 	}

client/ssh/client/client.go

@@ -24,6 +24,7 @@ import (
 	"github.com/netbirdio/netbird/client/proto"
 	nbssh "github.com/netbirdio/netbird/client/ssh"
 	"github.com/netbirdio/netbird/client/ssh/detection"
+	"github.com/netbirdio/netbird/util"
 )
 
 const (
@@ -278,6 +279,7 @@ type DialOptions struct {
 	DaemonAddr         string
 	SkipCachedToken    bool
 	InsecureSkipVerify bool
+	NoBrowser          bool
 }
 
 // Dial connects to the given ssh server with specified options
@@ -307,7 +309,7 @@ func Dial(ctx context.Context, addr, user string, opts DialOptions) (*Client, er
 		config.Auth = append(config.Auth, authMethod)
 	}
 
-	return dialWithJWT(ctx, "tcp", addr, config, daemonAddr, opts.SkipCachedToken)
+	return dialWithJWT(ctx, "tcp", addr, config, daemonAddr, opts.SkipCachedToken, opts.NoBrowser)
 }
 
 // dialSSH establishes an SSH connection without JWT authentication
@@ -333,7 +335,7 @@ func dialSSH(ctx context.Context, network, addr string, config *ssh.ClientConfig
 }
 
 // dialWithJWT establishes an SSH connection with optional JWT authentication based on server detection
-func dialWithJWT(ctx context.Context, network, addr string, config *ssh.ClientConfig, daemonAddr string, skipCache bool) (*Client, error) {
+func dialWithJWT(ctx context.Context, network, addr string, config *ssh.ClientConfig, daemonAddr string, skipCache, noBrowser bool) (*Client, error) {
 	host, portStr, err := net.SplitHostPort(addr)
 	if err != nil {
 		return nil, fmt.Errorf("parse address %s: %w", addr, err)
@@ -359,7 +361,7 @@ func dialWithJWT(ctx context.Context, network, addr string, config *ssh.ClientCo
 	jwtCtx, cancel := context.WithTimeout(ctx, config.Timeout)
 	defer cancel()
 
-	jwtToken, err := requestJWTToken(jwtCtx, daemonAddr, skipCache)
+	jwtToken, err := requestJWTToken(jwtCtx, daemonAddr, skipCache, noBrowser)
 	if err != nil {
 		return nil, fmt.Errorf("request JWT token: %w", err)
 	}
@@ -369,7 +371,7 @@ func dialWithJWT(ctx context.Context, network, addr string, config *ssh.ClientCo
 }
 
 // requestJWTToken requests a JWT token from the NetBird daemon
-func requestJWTToken(ctx context.Context, daemonAddr string, skipCache bool) (string, error) {
+func requestJWTToken(ctx context.Context, daemonAddr string, skipCache, noBrowser bool) (string, error) {
 	hint := profilemanager.GetLoginHint()
 
 	conn, err := connectToDaemon(daemonAddr)
@@ -379,7 +381,13 @@ func requestJWTToken(ctx context.Context, daemonAddr string, skipCache bool) (st
 	defer conn.Close()
 
 	client := proto.NewDaemonServiceClient(conn)
-	return nbssh.RequestJWTToken(ctx, client, os.Stdout, os.Stderr, !skipCache, hint)
+
+	var browserOpener func(string) error
+	if !noBrowser {
+		browserOpener = util.OpenBrowser
+	}
+
+	return nbssh.RequestJWTToken(ctx, client, os.Stdout, os.Stderr, !skipCache, hint, browserOpener)
 }
 
 // verifyHostKeyViaDaemon verifies SSH host key by querying the NetBird daemon

client/ssh/common.go

@@ -67,8 +67,31 @@ func (d *DaemonHostKeyVerifier) VerifySSHHostKey(peerAddress string, presentedKe
 	return VerifyHostKey(storedKeyData, presentedKey, peerAddress)
 }
 
+// printAuthInstructions prints authentication instructions to stderr
+func printAuthInstructions(stderr io.Writer, authResponse *proto.RequestJWTAuthResponse, browserWillOpen bool) {
+	_, _ = fmt.Fprintln(stderr, "SSH authentication required.")
+
+	if browserWillOpen {
+		_, _ = fmt.Fprintln(stderr, "Please do the SSO login in your browser.")
+		_, _ = fmt.Fprintln(stderr, "If your browser didn't open automatically, use this URL to log in:")
+		_, _ = fmt.Fprintln(stderr)
+	}
+
+	_, _ = fmt.Fprintf(stderr, "%s\n", authResponse.VerificationURIComplete)
+
+	if authResponse.UserCode != "" {
+		_, _ = fmt.Fprintf(stderr, "Or visit: %s and enter code: %s\n", authResponse.VerificationURI, authResponse.UserCode)
+	}
+
+	if browserWillOpen {
+		_, _ = fmt.Fprintln(stderr)
+	}
+
+	_, _ = fmt.Fprintln(stderr, "Waiting for authentication...")
+}
+
 // RequestJWTToken requests or retrieves a JWT token for SSH authentication
-func RequestJWTToken(ctx context.Context, client proto.DaemonServiceClient, stdout, stderr io.Writer, useCache bool, hint string) (string, error) {
+func RequestJWTToken(ctx context.Context, client proto.DaemonServiceClient, stdout, stderr io.Writer, useCache bool, hint string, openBrowser func(string) error) (string, error) {
 	req := &proto.RequestJWTAuthRequest{}
 	if hint != "" {
 		req.Hint = &hint
@@ -84,12 +107,13 @@ func RequestJWTToken(ctx context.Context, client proto.DaemonServiceClient, stdo
 	}
 
 	if stderr != nil {
-		_, _ = fmt.Fprintln(stderr, "SSH authentication required.")
+		printAuthInstructions(stderr, authResponse, openBrowser != nil)
-		_, _ = fmt.Fprintf(stderr, "Please visit: %s\n", authResponse.VerificationURIComplete)
+	}
-		if authResponse.UserCode != "" {
+
-			_, _ = fmt.Fprintf(stderr, "Or visit: %s and enter code: %s\n", authResponse.VerificationURI, authResponse.UserCode)
+	if openBrowser != nil {
+		if err := openBrowser(authResponse.VerificationURIComplete); err != nil {
+			log.Debugf("open browser: %v", err)
 		}
-		_, _ = fmt.Fprintln(stderr, "Waiting for authentication...")
 	}
 
 	tokenResponse, err := client.WaitJWTToken(ctx, &proto.WaitJWTTokenRequest{

client/ssh/proxy/proxy.go

@@ -35,15 +35,16 @@ const (
 )
 
 type SSHProxy struct {
-	daemonAddr   string
+	daemonAddr    string
-	targetHost   string
+	targetHost    string
-	targetPort   int
+	targetPort    int
-	stderr       io.Writer
+	stderr        io.Writer
-	conn         *grpc.ClientConn
+	conn          *grpc.ClientConn
-	daemonClient proto.DaemonServiceClient
+	daemonClient  proto.DaemonServiceClient
+	browserOpener func(string) error
 }
 
-func New(daemonAddr, targetHost string, targetPort int, stderr io.Writer) (*SSHProxy, error) {
+func New(daemonAddr, targetHost string, targetPort int, stderr io.Writer, browserOpener func(string) error) (*SSHProxy, error) {
 	grpcAddr := strings.TrimPrefix(daemonAddr, "tcp://")
 	grpcConn, err := grpc.NewClient(grpcAddr, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	if err != nil {
@@ -51,12 +52,13 @@ func New(daemonAddr, targetHost string, targetPort int, stderr io.Writer) (*SSHP
 	}
 
 	return &SSHProxy{
-		daemonAddr:   daemonAddr,
+		daemonAddr:    daemonAddr,
-		targetHost:   targetHost,
+		targetHost:    targetHost,
-		targetPort:   targetPort,
+		targetPort:    targetPort,
-		stderr:       stderr,
+		stderr:        stderr,
-		conn:         grpcConn,
+		conn:          grpcConn,
-		daemonClient: proto.NewDaemonServiceClient(grpcConn),
+		daemonClient:  proto.NewDaemonServiceClient(grpcConn),
+		browserOpener: browserOpener,
 	}, nil
 }
 
@@ -70,7 +72,7 @@ func (p *SSHProxy) Close() error {
 func (p *SSHProxy) Connect(ctx context.Context) error {
 	hint := profilemanager.GetLoginHint()
 
-	jwtToken, err := nbssh.RequestJWTToken(ctx, p.daemonClient, nil, p.stderr, true, hint)
+	jwtToken, err := nbssh.RequestJWTToken(ctx, p.daemonClient, nil, p.stderr, true, hint, p.browserOpener)
 	if err != nil {
 		return fmt.Errorf(jwtAuthErrorMsg, err)
 	}

client/ssh/proxy/proxy_test.go

@@ -153,7 +153,7 @@ func TestSSHProxy_Connect(t *testing.T) {
 	validToken := generateValidJWT(t, privateKey, issuer, audience)
 	mockDaemon.setJWTToken(validToken)
 
-	proxyInstance, err := New(mockDaemon.addr, host, port, nil)
+	proxyInstance, err := New(mockDaemon.addr, host, port, nil, nil)
 	require.NoError(t, err)
 
 	clientConn, proxyConn := net.Pipe()

util/common.go

@@ -1,6 +1,19 @@
 package util
 
-import "os"
+import (
+	"os"
+	"os/exec"
+
+	"github.com/skratchdot/open-golang/open"
+)
+
+// OpenBrowser opens the URL in a browser, respecting the BROWSER environment variable.
+func OpenBrowser(url string) error {
+	if browser := os.Getenv("BROWSER"); browser != "" {
+		return exec.Command(browser, url).Start()
+	}
+	return open.Run(url)
+}
 
 // SliceDiff returns the elements in slice `x` that are not in slice `y`
 func SliceDiff(x, y []string) []string {