Example #1
0
func ExampleClient_Listen() {
	config := &ssh.ClientConfig{
		User: "******",
		Auth: []ssh.AuthMethod{
			ssh.Password("password"),
		},
	}
	// Dial your ssh server.
	conn, err := ssh.Dial("tcp", "localhost:22", config)
	if err != nil {
		log.Fatalf("unable to connect: %s", err)
	}
	defer conn.Close()

	// Request the remote side to open port 8080 on all interfaces.
	l, err := conn.Listen("tcp", "0.0.0.0:8080")
	if err != nil {
		log.Fatalf("unable to register tcp forward: %v", err)
	}
	defer l.Close()

	// Serve HTTP with your SSH server acting as a reverse proxy.
	http.Serve(l, http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
		fmt.Fprintf(resp, "Hello world!\n")
	}))
}
Example #2
0
func ExampleSession_RequestPty() {
	// Create client config
	config := &ssh.ClientConfig{
		User: "******",
		Auth: []ssh.AuthMethod{
			ssh.Password("password"),
		},
	}
	// Connect to ssh server
	conn, err := ssh.Dial("tcp", "localhost:22", config)
	if err != nil {
		log.Fatalf("unable to connect: %s", err)
	}
	defer conn.Close()
	// Create a session
	session, err := conn.NewSession()
	if err != nil {
		log.Fatalf("unable to create session: %s", err)
	}
	defer session.Close()
	// Set up terminal modes
	modes := ssh.TerminalModes{
		ssh.ECHO:          0,     // disable echoing
		ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
		ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
	}
	// Request pseudo terminal
	if err := session.RequestPty("xterm", 80, 40, modes); err != nil {
		log.Fatalf("request for pseudo terminal failed: %s", err)
	}
	// Start remote shell
	if err := session.Shell(); err != nil {
		log.Fatalf("failed to start shell: %s", err)
	}
}
Example #3
0
func ExampleDial() {
	// An SSH client is represented with a ClientConn. Currently only
	// the "password" authentication method is supported.
	//
	// To authenticate with the remote server you must pass at least one
	// implementation of AuthMethod via the Auth field in ClientConfig.
	config := &ssh.ClientConfig{
		User: "******",
		Auth: []ssh.AuthMethod{
			ssh.Password("yourpassword"),
		},
	}
	client, err := ssh.Dial("tcp", "yourserver.com:22", config)
	if err != nil {
		panic("Failed to dial: " + err.Error())
	}

	// Each ClientConn can support multiple interactive sessions,
	// represented by a Session.
	session, err := client.NewSession()
	if err != nil {
		panic("Failed to create session: " + err.Error())
	}
	defer session.Close()

	// Once a Session is created, you can execute a single command on
	// the remote side using the Run method.
	var b bytes.Buffer
	session.Stdout = &b
	if err := session.Run("/usr/bin/whoami"); err != nil {
		panic("Failed to run: " + err.Error())
	}
	fmt.Println(b.String())
}
Example #4
0
func (s *sshTunnel) Start(readyErrCh chan<- error, errCh chan<- error) {
	authMethods := []ssh.AuthMethod{}

	if s.options.PrivateKey != "" {
		s.logger.Debug(s.logTag, "Reading private key file '%s'", s.options.PrivateKey)
		keyContents, err := ioutil.ReadFile(s.options.PrivateKey)
		if err != nil {
			readyErrCh <- bosherr.WrapErrorf(err, "Reading private key file '%s'", s.options.PrivateKey)
			return
		}

		s.logger.Debug(s.logTag, "Parsing private key file '%s'", s.options.PrivateKey)
		signer, err := ssh.ParsePrivateKey(keyContents)
		if err != nil {
			readyErrCh <- bosherr.WrapErrorf(err, "Parsing private key file '%s'", s.options.PrivateKey)
			return
		}

		authMethods = append(authMethods, ssh.PublicKeys(signer))
	}

	if s.options.Password != "" {
		s.logger.Debug(s.logTag, "Adding password auth method to ssh tunnel config")

		keyboardInteractiveChallenge := func(
			user,
			instruction string,
			questions []string,
			echos []bool,
		) (answers []string, err error) {
			if len(questions) == 0 {
				return []string{}, nil
			}
			return []string{s.options.Password}, nil
		}
		authMethods = append(authMethods, ssh.KeyboardInteractive(keyboardInteractiveChallenge))
		authMethods = append(authMethods, ssh.Password(s.options.Password))
	}

	sshConfig := &ssh.ClientConfig{
		User: s.options.User,
		Auth: authMethods,
	}

	s.logger.Debug(s.logTag, "Dialing remote server at %s:%d", s.options.Host, s.options.Port)
	remoteAddr := fmt.Sprintf("%s:%d", s.options.Host, s.options.Port)

	retryStrategy := &SSHRetryStrategy{
		TimeService:              s.timeService,
		ConnectionRefusedTimeout: s.connectionRefusedTimeout,
		AuthFailureTimeout:       s.authFailureTimeout,
	}

	var conn *ssh.Client
	var err error
	for i := 0; ; i++ {
		s.logger.Debug(s.logTag, "Making attempt #%d", i)
		conn, err = ssh.Dial("tcp", remoteAddr, sshConfig)

		if err == nil {
			break
		}

		if !retryStrategy.IsRetryable(err) {
			readyErrCh <- bosherr.WrapError(err, "Failed to connect to remote server")
			return
		}

		s.logger.Debug(s.logTag, "Attempt failed #%d: Dialing remote server: %s", i, err.Error())

		time.Sleep(s.startDialDelay)
	}

	remoteListenAddr := fmt.Sprintf("127.0.0.1:%d", s.options.RemoteForwardPort)
	s.logger.Debug(s.logTag, "Listening on remote server %s", remoteListenAddr)
	s.remoteListener, err = conn.Listen("tcp", remoteListenAddr)
	if err != nil {
		readyErrCh <- bosherr.WrapError(err, "Listening on remote server")
		return
	}

	readyErrCh <- nil
	for {
		remoteConn, err := s.remoteListener.Accept()
		s.logger.Debug(s.logTag, "Received connection")
		if err != nil {
			errCh <- bosherr.WrapError(err, "Accepting connection on remote server")
		}
		defer func() {
			if err = remoteConn.Close(); err != nil {
				s.logger.Warn(s.logTag, "Failed to close remote listener connection: %s", err.Error())
			}
		}()

		s.logger.Debug(s.logTag, "Dialing local server")
		localDialAddr := fmt.Sprintf("127.0.0.1:%d", s.options.LocalForwardPort)
		localConn, err := net.Dial("tcp", localDialAddr)
		if err != nil {
			errCh <- bosherr.WrapError(err, "Dialing local server")
			return
		}

		go func() {
			bytesNum, err := io.Copy(remoteConn, localConn)
			defer func() {
				if err = localConn.Close(); err != nil {
					s.logger.Warn(s.logTag, "Failed to close local dial connection: %s", err.Error())
				}
			}()
			s.logger.Debug(s.logTag, "Copying bytes from local to remote %d", bytesNum)
			if err != nil {
				errCh <- bosherr.WrapError(err, "Copying bytes from local to remote")
			}
		}()

		go func() {
			bytesNum, err := io.Copy(localConn, remoteConn)
			defer func() {
				if err = localConn.Close(); err != nil {
					s.logger.Warn(s.logTag, "Failed to close local dial connection: %s", err.Error())
				}
			}()
			s.logger.Debug(s.logTag, "Copying bytes from remote to local %d", bytesNum)
			if err != nil {
				errCh <- bosherr.WrapError(err, "Copying bytes from remote to local")
			}
		}()
	}
}