exp/ssh: move common code to common.go
R=agl
CC=golang-dev
https://golang.org/cl/5132041
diff --git a/src/pkg/exp/ssh/Makefile b/src/pkg/exp/ssh/Makefile
index e8f33b7..1a100e9 100644
--- a/src/pkg/exp/ssh/Makefile
+++ b/src/pkg/exp/ssh/Makefile
@@ -6,11 +6,11 @@
TARG=exp/ssh
GOFILES=\
+ channel.go\
common.go\
messages.go\
- server.go\
transport.go\
- channel.go\
- server_shell.go\
+ server.go\
+ server_shell.go\
include ../../../Make.pkg
diff --git a/src/pkg/exp/ssh/common.go b/src/pkg/exp/ssh/common.go
index 698db60..441c5b1 100644
--- a/src/pkg/exp/ssh/common.go
+++ b/src/pkg/exp/ssh/common.go
@@ -5,7 +5,9 @@
package ssh
import (
+ "big"
"strconv"
+ "sync"
)
// These are string constants in the SSH protocol.
@@ -19,6 +21,32 @@
serviceSSH = "ssh-connection"
)
+var supportedKexAlgos = []string{kexAlgoDH14SHA1}
+var supportedHostKeyAlgos = []string{hostAlgoRSA}
+var supportedCiphers = []string{cipherAES128CTR}
+var supportedMACs = []string{macSHA196}
+var supportedCompressions = []string{compressionNone}
+
+// dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
+type dhGroup struct {
+ g, p *big.Int
+}
+
+// dhGroup14 is the group called diffie-hellman-group14-sha1 in RFC 4253 and
+// Oakley Group 14 in RFC 3526.
+var dhGroup14 *dhGroup
+
+var dhGroup14Once sync.Once
+
+func initDHGroup14() {
+ p, _ := new(big.Int).SetString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
+
+ dhGroup14 = &dhGroup{
+ g: new(big.Int).SetInt64(2),
+ p: p,
+ }
+}
+
// UnexpectedMessageError results when the SSH message that we received didn't
// match what we wanted.
type UnexpectedMessageError struct {
@@ -38,6 +66,11 @@
return "ssh: parse error in message type " + strconv.Itoa(int(p.msgType))
}
+type handshakeMagics struct {
+ clientVersion, serverVersion []byte
+ clientKexInit, serverKexInit []byte
+}
+
func findCommonAlgorithm(clientAlgos []string, serverAlgos []string) (commonAlgo string, ok bool) {
for _, clientAlgo := range clientAlgos {
for _, serverAlgo := range serverAlgos {
diff --git a/src/pkg/exp/ssh/messages.go b/src/pkg/exp/ssh/messages.go
index d375eaf..bc2333e 100644
--- a/src/pkg/exp/ssh/messages.go
+++ b/src/pkg/exp/ssh/messages.go
@@ -59,6 +59,13 @@
// in this file. The only wrinkle is that a final member of type []byte with a
// tag of "rest" receives the remainder of a packet when unmarshaling.
+// See RFC 4253, section 11.1.
+type disconnectMsg struct {
+ Reason uint32
+ Message string
+ Language string
+}
+
// See RFC 4253, section 7.1.
type kexInitMsg struct {
Cookie [16]byte
@@ -137,6 +144,12 @@
Language string
}
+// See RFC 4254, section 5.2.
+type channelData struct {
+ PeersId uint32
+ Payload []byte "rest"
+}
+
type channelRequestMsg struct {
PeersId uint32
Request string
@@ -555,3 +568,60 @@
}
var bigIntType = reflect.TypeOf((*big.Int)(nil))
+
+// Decode a packet into it's corresponding message.
+func decode(packet []byte) interface{} {
+ var msg interface{}
+ switch packet[0] {
+ case msgDisconnect:
+ msg = new(disconnectMsg)
+ case msgServiceRequest:
+ msg = new(serviceRequestMsg)
+ case msgServiceAccept:
+ msg = new(serviceAcceptMsg)
+ case msgKexInit:
+ msg = new(kexInitMsg)
+ case msgKexDHInit:
+ msg = new(kexDHInitMsg)
+ case msgKexDHReply:
+ msg = new(kexDHReplyMsg)
+ case msgUserAuthRequest:
+ msg = new(userAuthRequestMsg)
+ case msgUserAuthFailure:
+ msg = new(userAuthFailureMsg)
+ case msgUserAuthPubKeyOk:
+ msg = new(userAuthPubKeyOkMsg)
+ case msgGlobalRequest:
+ msg = new(globalRequestMsg)
+ case msgRequestSuccess:
+ msg = new(channelRequestSuccessMsg)
+ case msgRequestFailure:
+ msg = new(channelRequestFailureMsg)
+ case msgChannelOpen:
+ msg = new(channelOpenMsg)
+ case msgChannelOpenConfirm:
+ msg = new(channelOpenConfirmMsg)
+ case msgChannelOpenFailure:
+ msg = new(channelOpenFailureMsg)
+ case msgChannelWindowAdjust:
+ msg = new(windowAdjustMsg)
+ case msgChannelData:
+ msg = new(channelData)
+ case msgChannelEOF:
+ msg = new(channelEOFMsg)
+ case msgChannelClose:
+ msg = new(channelCloseMsg)
+ case msgChannelRequest:
+ msg = new(channelRequestMsg)
+ case msgChannelSuccess:
+ msg = new(channelRequestSuccessMsg)
+ case msgChannelFailure:
+ msg = new(channelRequestFailureMsg)
+ default:
+ return UnexpectedMessageError{0, packet[0]}
+ }
+ if err := unmarshal(msg, packet, packet[0]); err != nil {
+ return err
+ }
+ return msg
+}
diff --git a/src/pkg/exp/ssh/server.go b/src/pkg/exp/ssh/server.go
index bc0af13..9e7a255 100644
--- a/src/pkg/exp/ssh/server.go
+++ b/src/pkg/exp/ssh/server.go
@@ -6,7 +6,6 @@
import (
"big"
- "bufio"
"bytes"
"crypto"
"crypto/rand"
@@ -19,12 +18,6 @@
"sync"
)
-var supportedKexAlgos = []string{kexAlgoDH14SHA1}
-var supportedHostKeyAlgos = []string{hostAlgoRSA}
-var supportedCiphers = []string{cipherAES128CTR}
-var supportedMACs = []string{macSHA196}
-var supportedCompressions = []string{compressionNone}
-
// Server represents an SSH server. A Server may have several ServerConnections.
type Server struct {
rsa *rsa.PrivateKey
@@ -146,31 +139,6 @@
cachedPubKeys []cachedPubKey
}
-// dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
-type dhGroup struct {
- g, p *big.Int
-}
-
-// dhGroup14 is the group called diffie-hellman-group14-sha1 in RFC 4253 and
-// Oakley Group 14 in RFC 3526.
-var dhGroup14 *dhGroup
-
-var dhGroup14Once sync.Once
-
-func initDHGroup14() {
- p, _ := new(big.Int).SetString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
-
- dhGroup14 = &dhGroup{
- g: new(big.Int).SetInt64(2),
- p: p,
- }
-}
-
-type handshakeMagics struct {
- clientVersion, serverVersion []byte
- clientKexInit, serverKexInit []byte
-}
-
// kexDH performs Diffie-Hellman key agreement on a ServerConnection. The
// returned values are given the same names as in RFC 4253, section 8.
func (s *ServerConnection) kexDH(group *dhGroup, hashFunc crypto.Hash, magics *handshakeMagics, hostKeyAlgo string) (H, K []byte, err os.Error) {
@@ -292,18 +260,7 @@
// Handshake performs an SSH transport and client authentication on the given ServerConnection.
func (s *ServerConnection) Handshake(conn net.Conn) os.Error {
var magics handshakeMagics
- s.transport = &transport{
- reader: reader{
- Reader: bufio.NewReader(conn),
- },
- writer: writer{
- Writer: bufio.NewWriter(conn),
- rand: rand.Reader,
- },
- Close: func() os.Error {
- return conn.Close()
- },
- }
+ s.transport = newTransport(conn)
if _, err := conn.Write(serverVersion); err != nil {
return err
@@ -612,19 +569,14 @@
return nil, err
}
- switch packet[0] {
- case msgChannelOpen:
- var chanOpen channelOpenMsg
- if err := unmarshal(&chanOpen, packet, msgChannelOpen); err != nil {
- return nil, err
- }
-
+ switch msg := decode(packet).(type) {
+ case *channelOpenMsg:
c := new(channel)
- c.chanType = chanOpen.ChanType
- c.theirId = chanOpen.PeersId
- c.theirWindow = chanOpen.PeersWindow
- c.maxPacketSize = chanOpen.MaxPacketSize
- c.extraData = chanOpen.TypeSpecificData
+ c.chanType = msg.ChanType
+ c.theirId = msg.PeersId
+ c.theirWindow = msg.PeersWindow
+ c.maxPacketSize = msg.MaxPacketSize
+ c.extraData = msg.TypeSpecificData
c.myWindow = defaultWindowSize
c.serverConn = s
c.cond = sync.NewCond(&c.lock)
@@ -637,74 +589,53 @@
s.lock.Unlock()
return c, nil
- case msgChannelRequest:
- var chanRequest channelRequestMsg
- if err := unmarshal(&chanRequest, packet, msgChannelRequest); err != nil {
- return nil, err
- }
-
+ case *channelRequestMsg:
s.lock.Lock()
- c, ok := s.channels[chanRequest.PeersId]
+ c, ok := s.channels[msg.PeersId]
if !ok {
continue
}
- c.handlePacket(&chanRequest)
+ c.handlePacket(msg)
s.lock.Unlock()
- case msgChannelData:
- if len(packet) < 5 {
- return nil, ParseError{msgChannelData}
- }
- chanId := uint32(packet[1])<<24 | uint32(packet[2])<<16 | uint32(packet[3])<<8 | uint32(packet[4])
-
+ case *channelData:
s.lock.Lock()
- c, ok := s.channels[chanId]
+ c, ok := s.channels[msg.PeersId]
if !ok {
continue
}
- c.handleData(packet[9:])
+ c.handleData(msg.Payload)
s.lock.Unlock()
- case msgChannelEOF:
- var eofMsg channelEOFMsg
- if err := unmarshal(&eofMsg, packet, msgChannelEOF); err != nil {
- return nil, err
- }
-
+ case *channelEOFMsg:
s.lock.Lock()
- c, ok := s.channels[eofMsg.PeersId]
+ c, ok := s.channels[msg.PeersId]
if !ok {
continue
}
- c.handlePacket(&eofMsg)
+ c.handlePacket(msg)
s.lock.Unlock()
- case msgChannelClose:
- var closeMsg channelCloseMsg
- if err := unmarshal(&closeMsg, packet, msgChannelClose); err != nil {
- return nil, err
- }
-
+ case *channelCloseMsg:
s.lock.Lock()
- c, ok := s.channels[closeMsg.PeersId]
+ c, ok := s.channels[msg.PeersId]
if !ok {
continue
}
- c.handlePacket(&closeMsg)
+ c.handlePacket(msg)
s.lock.Unlock()
- case msgGlobalRequest:
- var request globalRequestMsg
- if err := unmarshal(&request, packet, msgGlobalRequest); err != nil {
- return nil, err
- }
-
- if request.WantReply {
+ case *globalRequestMsg:
+ if msg.WantReply {
if err := s.writePacket([]byte{msgRequestFailure}); err != nil {
return nil, err
}
}
+ case UnexpectedMessageError:
+ return nil, msg
+ case *disconnectMsg:
+ return nil, os.EOF
default:
// Unknown message. Ignore.
}
diff --git a/src/pkg/exp/ssh/transport.go b/src/pkg/exp/ssh/transport.go
index 5a474a9..77660a2 100644
--- a/src/pkg/exp/ssh/transport.go
+++ b/src/pkg/exp/ssh/transport.go
@@ -10,10 +10,13 @@
"crypto/aes"
"crypto/cipher"
"crypto/hmac"
+ "crypto/rand"
"crypto/subtle"
"hash"
"io"
+ "net"
"os"
+ "sync"
)
const (
@@ -29,7 +32,8 @@
macAlgo string
compressionAlgo string
- Close func() os.Error
+ Close func() os.Error
+ RemoteAddr func() net.Addr
}
// reader represents the incoming connection state.
@@ -40,6 +44,7 @@
// writer represnts the outgoing connection state.
type writer struct {
+ *sync.Mutex // protects writer.Writer from concurrent writes
*bufio.Writer
paddingMultiple int
rand io.Reader
@@ -126,6 +131,9 @@
// Encrypt and send a packet of data to the remote peer.
func (w *writer) writePacket(packet []byte) os.Error {
+ w.Mutex.Lock()
+ defer w.Mutex.Unlock()
+
paddingLength := paddingMultiple - (5+len(packet))%paddingMultiple
if paddingLength < 4 {
paddingLength += paddingMultiple
@@ -190,6 +198,31 @@
return err
}
+// Send a message to the remote peer
+func (t *transport) sendMessage(typ uint8, msg interface{}) os.Error {
+ packet := marshal(typ, msg)
+ return t.writePacket(packet)
+}
+
+func newTransport(conn net.Conn) *transport {
+ return &transport{
+ reader: reader{
+ Reader: bufio.NewReader(conn),
+ },
+ writer: writer{
+ Writer: bufio.NewWriter(conn),
+ rand: rand.Reader,
+ Mutex: new(sync.Mutex),
+ },
+ Close: func() os.Error {
+ return conn.Close()
+ },
+ RemoteAddr: func() net.Addr {
+ return conn.RemoteAddr()
+ },
+ }
+}
+
type direction struct {
ivTag []byte
keyTag []byte
