mirror of
https://github.com/golang/go
synced 2024-11-02 11:50:30 +00:00
exp/ssh: server cleanups
server.go/channel.go: * rename Server to ServerConfig to match Client. * rename ServerConnection to ServeConn to match Client. * add Listen/Listener. * ServerConn.Handshake(), general cleanups. client.go: * fix bug where fmt.Error was not assigned to err R=rsc, agl CC=golang-dev https://golang.org/cl/5265049
This commit is contained in:
parent
792a55f5db
commit
8bfb217123
3 changed files with 102 additions and 49 deletions
|
@ -68,7 +68,7 @@ type channel struct {
|
|||
weClosed bool
|
||||
dead bool
|
||||
|
||||
serverConn *ServerConnection
|
||||
serverConn *ServerConn
|
||||
myId, theirId uint32
|
||||
myWindow, theirWindow uint32
|
||||
maxPacketSize uint32
|
||||
|
|
|
@ -115,7 +115,7 @@ func (c *ClientConn) handshake() os.Error {
|
|||
dhGroup14Once.Do(initDHGroup14)
|
||||
H, K, err = c.kexDH(dhGroup14, hashFunc, &magics, hostKeyAlgo)
|
||||
default:
|
||||
fmt.Errorf("ssh: unexpected key exchange algorithm %v", kexAlgo)
|
||||
err = fmt.Errorf("ssh: unexpected key exchange algorithm %v", kexAlgo)
|
||||
}
|
||||
if err != nil {
|
||||
return err
|
||||
|
|
|
@ -10,19 +10,23 @@ import (
|
|||
"crypto"
|
||||
"crypto/rand"
|
||||
"crypto/rsa"
|
||||
_ "crypto/sha1"
|
||||
"crypto/x509"
|
||||
"encoding/pem"
|
||||
"io"
|
||||
"net"
|
||||
"os"
|
||||
"sync"
|
||||
)
|
||||
|
||||
// Server represents an SSH server. A Server may have several ServerConnections.
|
||||
type Server struct {
|
||||
type ServerConfig struct {
|
||||
rsa *rsa.PrivateKey
|
||||
rsaSerialized []byte
|
||||
|
||||
// Rand provides the source of entropy for key exchange. If Rand is
|
||||
// nil, the cryptographic random reader in package crypto/rand will
|
||||
// be used.
|
||||
Rand io.Reader
|
||||
|
||||
// NoClientAuth is true if clients are allowed to connect without
|
||||
// authenticating.
|
||||
NoClientAuth bool
|
||||
|
@ -38,11 +42,18 @@ type Server struct {
|
|||
PubKeyCallback func(user, algo string, pubkey []byte) bool
|
||||
}
|
||||
|
||||
func (c *ServerConfig) rand() io.Reader {
|
||||
if c.Rand == nil {
|
||||
return rand.Reader
|
||||
}
|
||||
return c.Rand
|
||||
}
|
||||
|
||||
// SetRSAPrivateKey sets the private key for a Server. A Server must have a
|
||||
// private key configured in order to accept connections. The private key must
|
||||
// be in the form of a PEM encoded, PKCS#1, RSA private key. The file "id_rsa"
|
||||
// typically contains such a key.
|
||||
func (s *Server) SetRSAPrivateKey(pemBytes []byte) os.Error {
|
||||
func (s *ServerConfig) SetRSAPrivateKey(pemBytes []byte) os.Error {
|
||||
block, _ := pem.Decode(pemBytes)
|
||||
if block == nil {
|
||||
return os.NewError("ssh: no key found")
|
||||
|
@ -109,7 +120,7 @@ func parseRSASig(in []byte) (sig []byte, ok bool) {
|
|||
}
|
||||
|
||||
// cachedPubKey contains the results of querying whether a public key is
|
||||
// acceptable for a user. The cache only applies to a single ServerConnection.
|
||||
// acceptable for a user. The cache only applies to a single ServerConn.
|
||||
type cachedPubKey struct {
|
||||
user, algo string
|
||||
pubKey []byte
|
||||
|
@ -118,11 +129,10 @@ type cachedPubKey struct {
|
|||
|
||||
const maxCachedPubKeys = 16
|
||||
|
||||
// ServerConnection represents an incomming connection to a Server.
|
||||
type ServerConnection struct {
|
||||
Server *Server
|
||||
|
||||
// A ServerConn represents an incomming connection.
|
||||
type ServerConn struct {
|
||||
*transport
|
||||
config *ServerConfig
|
||||
|
||||
channels map[uint32]*channel
|
||||
nextChanId uint32
|
||||
|
@ -139,9 +149,20 @@ type ServerConnection struct {
|
|||
cachedPubKeys []cachedPubKey
|
||||
}
|
||||
|
||||
// Server returns a new SSH server connection
|
||||
// using c as the underlying transport.
|
||||
func Server(c net.Conn, config *ServerConfig) *ServerConn {
|
||||
conn := &ServerConn{
|
||||
transport: newTransport(c, config.rand()),
|
||||
channels: make(map[uint32]*channel),
|
||||
config: config,
|
||||
}
|
||||
return conn
|
||||
}
|
||||
|
||||
// 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) {
|
||||
func (s *ServerConn) kexDH(group *dhGroup, hashFunc crypto.Hash, magics *handshakeMagics, hostKeyAlgo string) (H, K []byte, err os.Error) {
|
||||
packet, err := s.readPacket()
|
||||
if err != nil {
|
||||
return
|
||||
|
@ -155,7 +176,7 @@ func (s *ServerConnection) kexDH(group *dhGroup, hashFunc crypto.Hash, magics *h
|
|||
return nil, nil, os.NewError("client DH parameter out of bounds")
|
||||
}
|
||||
|
||||
y, err := rand.Int(rand.Reader, group.p)
|
||||
y, err := rand.Int(s.config.rand(), group.p)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
|
@ -166,7 +187,7 @@ func (s *ServerConnection) kexDH(group *dhGroup, hashFunc crypto.Hash, magics *h
|
|||
var serializedHostKey []byte
|
||||
switch hostKeyAlgo {
|
||||
case hostAlgoRSA:
|
||||
serializedHostKey = s.Server.rsaSerialized
|
||||
serializedHostKey = s.config.rsaSerialized
|
||||
default:
|
||||
return nil, nil, os.NewError("internal error")
|
||||
}
|
||||
|
@ -192,7 +213,7 @@ func (s *ServerConnection) kexDH(group *dhGroup, hashFunc crypto.Hash, magics *h
|
|||
var sig []byte
|
||||
switch hostKeyAlgo {
|
||||
case hostAlgoRSA:
|
||||
sig, err = rsa.SignPKCS1v15(rand.Reader, s.Server.rsa, hashFunc, hh)
|
||||
sig, err = rsa.SignPKCS1v15(s.config.rand(), s.config.rsa, hashFunc, hh)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
|
@ -257,17 +278,18 @@ func buildDataSignedForAuth(sessionId []byte, req userAuthRequestMsg, algo, pubK
|
|||
return ret
|
||||
}
|
||||
|
||||
// Handshake performs an SSH transport and client authentication on the given ServerConnection.
|
||||
func (s *ServerConnection) Handshake(conn net.Conn) os.Error {
|
||||
// Handshake performs an SSH transport and client authentication on the given ServerConn.
|
||||
func (s *ServerConn) Handshake() os.Error {
|
||||
var magics handshakeMagics
|
||||
s.transport = newTransport(conn, rand.Reader)
|
||||
|
||||
if _, err := conn.Write(serverVersion); err != nil {
|
||||
if _, err := s.Write(serverVersion); err != nil {
|
||||
return err
|
||||
}
|
||||
if err := s.Flush(); err != nil {
|
||||
return err
|
||||
}
|
||||
magics.serverVersion = serverVersion[:len(serverVersion)-2]
|
||||
|
||||
version, err := readVersion(s.transport)
|
||||
version, err := readVersion(s)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
@ -310,8 +332,7 @@ func (s *ServerConnection) Handshake(conn net.Conn) os.Error {
|
|||
if clientKexInit.FirstKexFollows && kexAlgo != clientKexInit.KexAlgos[0] {
|
||||
// The client sent a Kex message for the wrong algorithm,
|
||||
// which we have to ignore.
|
||||
_, err := s.readPacket()
|
||||
if err != nil {
|
||||
if _, err := s.readPacket(); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
@ -324,32 +345,27 @@ func (s *ServerConnection) Handshake(conn net.Conn) os.Error {
|
|||
dhGroup14Once.Do(initDHGroup14)
|
||||
H, K, err = s.kexDH(dhGroup14, hashFunc, &magics, hostKeyAlgo)
|
||||
default:
|
||||
err = os.NewError("ssh: internal error")
|
||||
err = os.NewError("ssh: unexpected key exchange algorithm " + kexAlgo)
|
||||
}
|
||||
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
packet = []byte{msgNewKeys}
|
||||
if err = s.writePacket(packet); err != nil {
|
||||
if err = s.writePacket([]byte{msgNewKeys}); err != nil {
|
||||
return err
|
||||
}
|
||||
if err = s.transport.writer.setupKeys(serverKeys, K, H, H, hashFunc); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if packet, err = s.readPacket(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if packet[0] != msgNewKeys {
|
||||
return UnexpectedMessageError{msgNewKeys, packet[0]}
|
||||
}
|
||||
|
||||
s.transport.reader.setupKeys(clientKeys, K, H, H, hashFunc)
|
||||
|
||||
packet, err = s.readPacket()
|
||||
if err != nil {
|
||||
if packet, err = s.readPacket(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
|
@ -360,20 +376,16 @@ func (s *ServerConnection) Handshake(conn net.Conn) os.Error {
|
|||
if serviceRequest.Service != serviceUserAuth {
|
||||
return os.NewError("ssh: requested service '" + serviceRequest.Service + "' before authenticating")
|
||||
}
|
||||
|
||||
serviceAccept := serviceAcceptMsg{
|
||||
Service: serviceUserAuth,
|
||||
}
|
||||
packet = marshal(msgServiceAccept, serviceAccept)
|
||||
if err = s.writePacket(packet); err != nil {
|
||||
if err = s.writePacket(marshal(msgServiceAccept, serviceAccept)); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if err = s.authenticate(H); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
s.channels = make(map[uint32]*channel)
|
||||
return nil
|
||||
}
|
||||
|
||||
|
@ -382,8 +394,8 @@ func isAcceptableAlgo(algo string) bool {
|
|||
}
|
||||
|
||||
// testPubKey returns true if the given public key is acceptable for the user.
|
||||
func (s *ServerConnection) testPubKey(user, algo string, pubKey []byte) bool {
|
||||
if s.Server.PubKeyCallback == nil || !isAcceptableAlgo(algo) {
|
||||
func (s *ServerConn) testPubKey(user, algo string, pubKey []byte) bool {
|
||||
if s.config.PubKeyCallback == nil || !isAcceptableAlgo(algo) {
|
||||
return false
|
||||
}
|
||||
|
||||
|
@ -393,7 +405,7 @@ func (s *ServerConnection) testPubKey(user, algo string, pubKey []byte) bool {
|
|||
}
|
||||
}
|
||||
|
||||
result := s.Server.PubKeyCallback(user, algo, pubKey)
|
||||
result := s.config.PubKeyCallback(user, algo, pubKey)
|
||||
if len(s.cachedPubKeys) < maxCachedPubKeys {
|
||||
c := cachedPubKey{
|
||||
user: user,
|
||||
|
@ -408,7 +420,7 @@ func (s *ServerConnection) testPubKey(user, algo string, pubKey []byte) bool {
|
|||
return result
|
||||
}
|
||||
|
||||
func (s *ServerConnection) authenticate(H []byte) os.Error {
|
||||
func (s *ServerConn) authenticate(H []byte) os.Error {
|
||||
var userAuthReq userAuthRequestMsg
|
||||
var err os.Error
|
||||
var packet []byte
|
||||
|
@ -428,11 +440,11 @@ userAuthLoop:
|
|||
|
||||
switch userAuthReq.Method {
|
||||
case "none":
|
||||
if s.Server.NoClientAuth {
|
||||
if s.config.NoClientAuth {
|
||||
break userAuthLoop
|
||||
}
|
||||
case "password":
|
||||
if s.Server.PasswordCallback == nil {
|
||||
if s.config.PasswordCallback == nil {
|
||||
break
|
||||
}
|
||||
payload := userAuthReq.Payload
|
||||
|
@ -445,11 +457,11 @@ userAuthLoop:
|
|||
return ParseError{msgUserAuthRequest}
|
||||
}
|
||||
|
||||
if s.Server.PasswordCallback(userAuthReq.User, string(password)) {
|
||||
if s.config.PasswordCallback(userAuthReq.User, string(password)) {
|
||||
break userAuthLoop
|
||||
}
|
||||
case "publickey":
|
||||
if s.Server.PubKeyCallback == nil {
|
||||
if s.config.PubKeyCallback == nil {
|
||||
break
|
||||
}
|
||||
payload := userAuthReq.Payload
|
||||
|
@ -520,10 +532,10 @@ userAuthLoop:
|
|||
}
|
||||
|
||||
var failureMsg userAuthFailureMsg
|
||||
if s.Server.PasswordCallback != nil {
|
||||
if s.config.PasswordCallback != nil {
|
||||
failureMsg.Methods = append(failureMsg.Methods, "password")
|
||||
}
|
||||
if s.Server.PubKeyCallback != nil {
|
||||
if s.config.PubKeyCallback != nil {
|
||||
failureMsg.Methods = append(failureMsg.Methods, "publickey")
|
||||
}
|
||||
|
||||
|
@ -546,9 +558,9 @@ userAuthLoop:
|
|||
|
||||
const defaultWindowSize = 32768
|
||||
|
||||
// Accept reads and processes messages on a ServerConnection. It must be called
|
||||
// Accept reads and processes messages on a ServerConn. It must be called
|
||||
// in order to demultiplex messages to any resulting Channels.
|
||||
func (s *ServerConnection) Accept() (Channel, os.Error) {
|
||||
func (s *ServerConn) Accept() (Channel, os.Error) {
|
||||
if s.err != nil {
|
||||
return nil, s.err
|
||||
}
|
||||
|
@ -643,3 +655,44 @@ func (s *ServerConnection) Accept() (Channel, os.Error) {
|
|||
|
||||
panic("unreachable")
|
||||
}
|
||||
|
||||
// A Listener implements a network listener (net.Listener) for SSH connections.
|
||||
type Listener struct {
|
||||
listener net.Listener
|
||||
config *ServerConfig
|
||||
}
|
||||
|
||||
// Accept waits for and returns the next incoming SSH connection.
|
||||
// The receiver should call Handshake() in another goroutine
|
||||
// to avoid blocking the accepter.
|
||||
func (l *Listener) Accept() (*ServerConn, os.Error) {
|
||||
c, err := l.listener.Accept()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
conn := Server(c, l.config)
|
||||
return conn, nil
|
||||
}
|
||||
|
||||
// Addr returns the listener's network address.
|
||||
func (l *Listener) Addr() net.Addr {
|
||||
return l.listener.Addr()
|
||||
}
|
||||
|
||||
// Close closes the listener.
|
||||
func (l *Listener) Close() os.Error {
|
||||
return l.listener.Close()
|
||||
}
|
||||
|
||||
// Listen creates an SSH listener accepting connections on
|
||||
// the given network address using net.Listen.
|
||||
func Listen(network, addr string, config *ServerConfig) (*Listener, os.Error) {
|
||||
l, err := net.Listen(network, addr)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &Listener{
|
||||
l,
|
||||
config,
|
||||
}, nil
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue