Ejemplo n.º 1
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)
			}
		}()
	}
}
Ejemplo n.º 2
0
func newServerShell(ch Channel, in <-chan *Request, prompt string) *terminal.Terminal {
	term := terminal.NewTerminal(ch, prompt)
	go handleTerminalRequests(in)
	return term
}
Ejemplo n.º 3
0
func (app *h2i) Main() error {
	cfg := &tls.Config{
		ServerName:         app.host,
		NextProtos:         strings.Split(*flagNextProto, ","),
		InsecureSkipVerify: *flagInsecure,
	}

	hostAndPort := withPort(app.host)
	log.Printf("Connecting to %s ...", hostAndPort)
	tc, err := tls.Dial("tcp", hostAndPort, cfg)
	if err != nil {
		return fmt.Errorf("Error dialing %s: %v", withPort(app.host), err)
	}
	log.Printf("Connected to %v", tc.RemoteAddr())
	defer tc.Close()

	if err := tc.Handshake(); err != nil {
		return fmt.Errorf("TLS handshake: %v", err)
	}
	if !*flagInsecure {
		if err := tc.VerifyHostname(app.host); err != nil {
			return fmt.Errorf("VerifyHostname: %v", err)
		}
	}
	state := tc.ConnectionState()
	log.Printf("Negotiated protocol %q", state.NegotiatedProtocol)
	if !state.NegotiatedProtocolIsMutual || state.NegotiatedProtocol == "" {
		return fmt.Errorf("Could not negotiate protocol mutually")
	}

	if _, err := io.WriteString(tc, http2.ClientPreface); err != nil {
		return err
	}

	app.framer = http2.NewFramer(tc, tc)

	oldState, err := terminal.MakeRaw(0)
	if err != nil {
		return err
	}
	defer terminal.Restore(0, oldState)

	var screen = struct {
		io.Reader
		io.Writer
	}{os.Stdin, os.Stdout}

	app.term = terminal.NewTerminal(screen, "h2i> ")
	lastWord := regexp.MustCompile(`.+\W(\w+)$`)
	app.term.AutoCompleteCallback = func(line string, pos int, key rune) (newLine string, newPos int, ok bool) {
		if key != '\t' {
			return
		}
		if pos != len(line) {
			// TODO: we're being lazy for now, only supporting tab completion at the end.
			return
		}
		// Auto-complete for the command itself.
		if !strings.Contains(line, " ") {
			var name string
			name, _, ok = lookupCommand(line)
			if !ok {
				return
			}
			return name, len(name), true
		}
		_, c, ok := lookupCommand(line[:strings.IndexByte(line, ' ')])
		if !ok || c.complete == nil {
			return
		}
		if strings.HasSuffix(line, " ") {
			app.logf("%s", strings.Join(c.complete(), " "))
			return line, pos, true
		}
		m := lastWord.FindStringSubmatch(line)
		if m == nil {
			return line, len(line), true
		}
		soFar := m[1]
		var match []string
		for _, cand := range c.complete() {
			if len(soFar) > len(cand) || !strings.EqualFold(cand[:len(soFar)], soFar) {
				continue
			}
			match = append(match, cand)
		}
		if len(match) == 0 {
			return
		}
		if len(match) > 1 {
			// TODO: auto-complete any common prefix
			app.logf("%s", strings.Join(match, " "))
			return line, pos, true
		}
		newLine = line[:len(line)-len(soFar)] + match[0]
		return newLine, len(newLine), true

	}

	errc := make(chan error, 2)
	go func() { errc <- app.readFrames() }()
	go func() { errc <- app.readConsole() }()
	return <-errc
}