Add sshchat dependencies in vendor

vendor/github.com/shazow/ssh-chat/sshd/terminal.go

@@ -0,0 +1,167 @@
+package sshd
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+var keepaliveInterval = time.Second * 30
+var keepaliveRequest = "keepalive@ssh-chat"
+
+var ErrNoSessionChannel = errors.New("no session channel")
+var ErrNotSessionChannel = errors.New("terminal requires session channel")
+
+// Connection is an interface with fields necessary to operate an sshd host.
+type Connection interface {
+	PublicKey() ssh.PublicKey
+	RemoteAddr() net.Addr
+	Name() string
+	ClientVersion() []byte
+	Close() error
+}
+
+type sshConn struct {
+	*ssh.ServerConn
+}
+
+func (c sshConn) PublicKey() ssh.PublicKey {
+	if c.Permissions == nil {
+		return nil
+	}
+
+	s, ok := c.Permissions.Extensions["pubkey"]
+	if !ok {
+		return nil
+	}
+
+	key, err := ssh.ParsePublicKey([]byte(s))
+	if err != nil {
+		return nil
+	}
+
+	return key
+}
+
+func (c sshConn) Name() string {
+	return c.User()
+}
+
+// Extending ssh/terminal to include a closer interface
+type Terminal struct {
+	terminal.Terminal
+	Conn    Connection
+	Channel ssh.Channel
+
+	done      chan struct{}
+	closeOnce sync.Once
+}
+
+// Make new terminal from a session channel
+func NewTerminal(conn *ssh.ServerConn, ch ssh.NewChannel) (*Terminal, error) {
+	if ch.ChannelType() != "session" {
+		return nil, ErrNotSessionChannel
+	}
+	channel, requests, err := ch.Accept()
+	if err != nil {
+		return nil, err
+	}
+	term := Terminal{
+		Terminal: *terminal.NewTerminal(channel, "Connecting..."),
+		Conn:     sshConn{conn},
+		Channel:  channel,
+
+		done: make(chan struct{}),
+	}
+
+	go term.listen(requests)
+
+	go func() {
+		// Keep-Alive Ticker
+		ticker := time.Tick(keepaliveInterval)
+		for {
+			select {
+			case <-ticker:
+				_, err := channel.SendRequest(keepaliveRequest, true, nil)
+				if err != nil {
+					// Connection is gone
+					logger.Printf("[%s] Keepalive failed, closing terminal: %s", term.Conn.RemoteAddr(), err)
+					term.Close()
+					return
+				}
+			case <-term.done:
+				return
+			}
+		}
+	}()
+
+	return &term, nil
+}
+
+// Find session channel and make a Terminal from it
+func NewSession(conn *ssh.ServerConn, channels <-chan ssh.NewChannel) (*Terminal, error) {
+	// Make a terminal from the first session found
+	for ch := range channels {
+		if t := ch.ChannelType(); t != "session" {
+			logger.Printf("[%s] Ignored channel type: %s", conn.RemoteAddr(), t)
+			ch.Reject(ssh.UnknownChannelType, fmt.Sprintf("unknown channel type: %s", t))
+			continue
+		}
+
+		return NewTerminal(conn, ch)
+	}
+
+	return nil, ErrNoSessionChannel
+}
+
+// Close terminal and ssh connection
+func (t *Terminal) Close() error {
+	var err error
+	t.closeOnce.Do(func() {
+		close(t.done)
+		t.Channel.Close()
+		err = t.Conn.Close()
+	})
+	return err
+}
+
+// Negotiate terminal type and settings
+func (t *Terminal) listen(requests <-chan *ssh.Request) {
+	hasShell := false
+
+	for req := range requests {
+		var width, height int
+		var ok bool
+
+		switch req.Type {
+		case "shell":
+			if !hasShell {
+				ok = true
+				hasShell = true
+			}
+		case "pty-req":
+			width, height, ok = parsePtyRequest(req.Payload)
+			if ok {
+				// TODO: Hardcode width to 100000?
+				err := t.SetSize(width, height)
+				ok = err == nil
+			}
+		case "window-change":
+			width, height, ok = parseWinchRequest(req.Payload)
+			if ok {
+				// TODO: Hardcode width to 100000?
+				err := t.SetSize(width, height)
+				ok = err == nil
+			}
+		}
+
+		if req.WantReply {
+			req.Reply(ok, nil)
+		}
+	}
+}