Beispiel #1
0
func newServerShell(ch *ServerChan, prompt string) *ServerTerminal {
	term := terminal.NewTerminal(ch, prompt)
	return &ServerTerminal{
		Term:    term,
		Channel: ch,
	}
}
Beispiel #2
0
func sshHandleChannel(conn net.Conn, newChannel ssh.NewChannel) {
	// Channels have a type, depending on the application level protocol
	// intended. In the case of a shell, the type is "session" and ServerShell
	// may be used to present a simple terminal interface.
	if newChannel.ChannelType() != "session" {
		newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
		return
	}
	channel, requests, err := newChannel.Accept()
	if err != nil {
		log.Errorln(err)
		return
	}

	// Sessions have out-of-band requests such as "shell", "pty-req" and "env".
	// Here we handle only the "shell" request.
	go func(in <-chan *ssh.Request) {
		for req := range in {
			ok := false
			switch req.Type {
			case "shell":
				ok = true
				if len(req.Payload) > 0 {
					// We don't accept any commands, only the default shell.
					ok = false
				}
			case "pty-req":
				ok = true
			}
			req.Reply(ok, nil)
		}
	}(requests)

	term := terminal.NewTerminal(channel, "> ")

	go func() {
		defer channel.Close()

		for {
			line, err := term.ReadLine()
			start := time.Now().UnixNano()
			if err != nil {
				if err != io.EOF {
					log.Errorln(err)
				}
				return
			}
			sshReportChan <- uint64(len(line))
			// just echo the message
			log.Debugln("ssh received: ", line)
			term.Write([]byte(line))
			term.Write([]byte{'\r', '\n'})

			stop := time.Now().UnixNano()
			log.Info("ssh %v %vns", conn.RemoteAddr(), uint64(stop-start))
		}
	}()
}
Beispiel #3
0
func sshHandleConn(conn *ssh.ServerConn) {
	for {
		channel, err := conn.Accept()
		if err != nil {
			if err != io.EOF {
				log.Errorln(err)
			}
			return
		}

		if channel.ChannelType() != "session" {
			channel.Reject(ssh.UnknownChannelType, "unknown channel type")
			continue
		}
		channel.Accept()

		term := terminal.NewTerminal(channel, "> ")
		serverTerm := &ssh.ServerTerminal{
			Term:    term,
			Channel: channel,
		}
		go func() {
			defer channel.Close()
			for {
				line, err := serverTerm.ReadLine()
				start := time.Now().UnixNano()
				if err != nil {
					if err != io.EOF {
						log.Errorln(err)
					}
					return
				}
				sshReportChan <- uint64(len(line))
				// just echo the message
				log.Debugln("ssh received: ", line)
				serverTerm.Write([]byte(line))
				serverTerm.Write([]byte{'\r', '\n'})

				stop := time.Now().UnixNano()
				log.Info("ssh %v %vns", conn.RemoteAddr(), uint64(stop-start))
			}
		}()
	}
}
Beispiel #4
0
func ExampleNewServerConn() {
	// An SSH server is represented by a ServerConfig, which holds
	// certificate details and handles authentication of ServerConns.
	config := &ssh.ServerConfig{
		PasswordCallback: func(c ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
			// Should use constant-time compare (or better, salt+hash) in
			// a production setting.
			if c.User() == "testuser" && string(pass) == "tiger" {
				return nil, nil
			}
			return nil, fmt.Errorf("password rejected for %q", c.User())
		},
	}

	privateBytes, err := ioutil.ReadFile("id_rsa")
	if err != nil {
		panic("Failed to load private key")
	}

	private, err := ssh.ParsePrivateKey(privateBytes)
	if err != nil {
		panic("Failed to parse private key")
	}

	config.AddHostKey(private)

	// Once a ServerConfig has been configured, connections can be
	// accepted.
	listener, err := net.Listen("tcp", "0.0.0.0:2022")
	if err != nil {
		panic("failed to listen for connection")
	}
	nConn, err := listener.Accept()
	if err != nil {
		panic("failed to accept incoming connection")
	}

	// Before use, a handshake must be performed on the incoming
	// net.Conn.
	_, chans, reqs, err := ssh.NewServerConn(nConn, config)
	if err != nil {
		panic("failed to handshake")
	}
	// The incoming Request channel must be serviced.
	go ssh.DiscardRequests(reqs)

	// Service the incoming Channel channel.
	for newChannel := range chans {
		// Channels have a type, depending on the application level
		// protocol intended. In the case of a shell, the type is
		// "session" and ServerShell may be used to present a simple
		// terminal interface.
		if newChannel.ChannelType() != "session" {
			newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
			continue
		}
		channel, requests, err := newChannel.Accept()
		if err != nil {
			panic("could not accept channel.")
		}

		// Sessions have out-of-band requests such as "shell",
		// "pty-req" and "env".  Here we handle only the
		// "shell" request.
		go func(in <-chan *ssh.Request) {
			for req := range in {
				ok := false
				switch req.Type {
				case "shell":
					ok = true
					if len(req.Payload) > 0 {
						// We don't accept any
						// commands, only the
						// default shell.
						ok = false
					}
				}
				req.Reply(ok, nil)
			}
		}(requests)

		term := terminal.NewTerminal(channel, "> ")

		go func() {
			defer channel.Close()
			for {
				line, err := term.ReadLine()
				if err != nil {
					break
				}
				fmt.Println(line)
			}
		}()
	}
}
Beispiel #5
0
func newServerShell(ch Channel, in <-chan *Request, prompt string) *terminal.Terminal {
	term := terminal.NewTerminal(ch, prompt)
	go handleTerminalRequests(in)
	return term
}
Beispiel #6
0
func ExampleListen() {
	// An SSH server is represented by a ServerConfig, which holds
	// certificate details and handles authentication of ServerConns.
	config := &ServerConfig{
		PasswordCallback: func(conn *ServerConn, user, pass string) bool {
			return user == "testuser" && pass == "tiger"
		},
	}

	pemBytes, err := ioutil.ReadFile("id_rsa")
	if err != nil {
		panic("Failed to load private key")
	}
	if err = config.SetRSAPrivateKey(pemBytes); err != nil {
		panic("Failed to parse private key")
	}

	// Once a ServerConfig has been configured, connections can be
	// accepted.
	listener, err := Listen("tcp", "0.0.0.0:2022", config)
	if err != nil {
		panic("failed to listen for connection")
	}
	sConn, err := listener.Accept()
	if err != nil {
		panic("failed to accept incoming connection")
	}
	if err := sConn.Handshake(); err != nil {
		panic("failed to handshake")
	}

	// A ServerConn multiplexes several channels, which must
	// themselves be Accepted.
	for {
		// Accept reads from the connection, demultiplexes packets
		// to their corresponding channels and returns when a new
		// channel request is seen. Some goroutine must always be
		// calling Accept; otherwise no messages will be forwarded
		// to the channels.
		channel, err := sConn.Accept()
		if err != nil {
			panic("error from Accept")
		}

		// Channels have a type, depending on the application level
		// protocol intended. In the case of a shell, the type is
		// "session" and ServerShell may be used to present a simple
		// terminal interface.
		if channel.ChannelType() != "session" {
			channel.Reject(UnknownChannelType, "unknown channel type")
			continue
		}
		channel.Accept()

		term := terminal.NewTerminal(channel, "> ")
		serverTerm := &ServerTerminal{
			Term:    term,
			Channel: channel,
		}
		go func() {
			defer channel.Close()
			for {
				line, err := serverTerm.ReadLine()
				if err != nil {
					break
				}
				fmt.Println(line)
			}
		}()
	}
}