code review 86190043: go.crypto/ssh: import gosshnew.

ssh/connection.go

Index: ssh/connection.go
===================================================================
new file mode 100644
--- /dev/null
+++ b/ssh/connection.go
@@ -0,0 +1,144 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"fmt"
+	"net"
+)
+
+// OpenChannelError is returned if the other side rejects an
+// OpenChannel request.
+type OpenChannelError struct {
+	Reason  RejectionReason
+	Message string
+}
+
+func (e *OpenChannelError) Error() string {
+	return fmt.Sprintf("ssh: rejected: %s (%s)", e.Reason, e.Message)
+}
+
+// ConnMetadata holds metadata for the connection.
+type ConnMetadata interface {
+	// User returns the user ID for this connection.
+	// It is empty if no authentication is used.
+	User() string
+
+	// SessionID returns the sesson hash, also denoted by H.
+	SessionID() []byte
+
+	// ClientVersion returns the client's version string as hashed
+	// into the session ID.
+	ClientVersion() []byte
+
+	// ServerVersion returns the client's version string as hashed
+	// into the session ID.
+	ServerVersion() []byte
+
+	// RemoteAddr returns the remote address for this connection.
+	RemoteAddr() net.Addr
+
+	// LocalAddr returns the local address for this connection.
+	LocalAddr() net.Addr
+}
+
+// Conn represents an SSH connection for both server and client roles.
+// Conn is the basis for implementing an application layer, such
+// as ClientConn, which implements the traditional shell access for
+// clients.
+type Conn interface {
+	ConnMetadata
+
+	// SendRequest sends a global request, and returns the
+	// reply. If wantReply is true, it returns the response status
+	// and payload. See also RFC4254, section 4.
+	SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error)
+
+	// OpenChannel tries to open an channel. If the request is
+	// rejected, it returns *OpenChannelError. On success it returns
+	// the SSH Channel and a Go channel for incoming, out-of-band
+	// requests. The Go channel must be serviced, or the
+	// connection will hang.
+	OpenChannel(name string, data []byte) (Channel, <-chan *Request, error)
+
+	// Close closes the underlying network connection
+	Close() error
+
+	// Wait blocks until the connection has shut down, and returns the
+	// error causing the shutdown.
+	Wait() error
+
+	// TODO(hanwen): consider exposing:
+	//   RequestKeyChange
+	//   Disconnect
+}
+
+// DiscardRequests consumes and rejects all requests from the
+// passed-in channel.
+func DiscardRequests(in <-chan *Request) {
+	for req := range in {
+		if req.WantReply {
+			req.Reply(false, nil)
+		}
+	}
+}
+
+// A connection represents an incoming connection.
+type connection struct {
+	transport *handshakeTransport
+	sshConn
+
+	// The connection protocol.
+	*mux
+}
+
+func (c *connection) Close() error {
+	return c.sshConn.conn.Close()
+}
+
+// sshconn provides net.Conn metadata, but disallows direct reads and
+// writes.
+type sshConn struct {
+	conn net.Conn
+
+	user          string
+	sessionID     []byte
+	clientVersion []byte
+	serverVersion []byte
+}
+
+func dup(src []byte) []byte {
+	dst := make([]byte, len(src))
+	copy(dst, src)
+	return dst
+}
+
+func (c *sshConn) User() string {
+	return c.user
+}
+
+func (c *sshConn) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+func (c *sshConn) Close() error {
+	return c.conn.Close()
+}
+
+func (c *sshConn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+func (c *sshConn) SessionID() []byte {
+	return dup(c.sessionID)
+}
+
+func (c *sshConn) ClientVersion() []byte {
+	return dup(c.clientVersion)
+}
+
+func (c *sshConn) ServerVersion() []byte {
+	return dup(c.serverVersion)
+}