cmd/puppeth, vendor: update ssh, manage server keys (#14398)

This commit is contained in:
Péter Szilágyi
2017-05-03 10:09:34 +03:00
committed by Felix Lange
parent 59966255ad
commit cf4faa491a
19 changed files with 704 additions and 288 deletions

View File

@ -268,7 +268,7 @@ type CertChecker struct {
// HostKeyFallback is called when CertChecker.CheckHostKey encounters a
// public key that is not a certificate. It must implement host key
// validation or else, if nil, all such keys are rejected.
HostKeyFallback func(addr string, remote net.Addr, key PublicKey) error
HostKeyFallback HostKeyCallback
// IsRevoked is called for each certificate so that revocation checking
// can be implemented. It should return true if the given certificate

View File

@ -5,6 +5,7 @@
package ssh
import (
"bytes"
"errors"
"fmt"
"net"
@ -13,7 +14,7 @@ import (
)
// Client implements a traditional SSH client that supports shells,
// subprocesses, port forwarding and tunneled dialing.
// subprocesses, TCP port/streamlocal forwarding and tunneled dialing.
type Client struct {
Conn
@ -59,6 +60,7 @@ func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
conn.forwards.closeAll()
}()
go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-tcpip"))
go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-streamlocal@openssh.com"))
return conn
}
@ -68,6 +70,11 @@ func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
func NewClientConn(c net.Conn, addr string, config *ClientConfig) (Conn, <-chan NewChannel, <-chan *Request, error) {
fullConf := *config
fullConf.SetDefaults()
if fullConf.HostKeyCallback == nil {
c.Close()
return nil, nil, nil, errors.New("ssh: must specify HostKeyCallback")
}
conn := &connection{
sshConn: sshConn{conn: c},
}
@ -173,6 +180,13 @@ func Dial(network, addr string, config *ClientConfig) (*Client, error) {
return NewClient(c, chans, reqs), nil
}
// HostKeyCallback is the function type used for verifying server
// keys. A HostKeyCallback must return nil if the host key is OK, or
// an error to reject it. It receives the hostname as passed to Dial
// or NewClientConn. The remote address is the RemoteAddr of the
// net.Conn underlying the the SSH connection.
type HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
// A ClientConfig structure is used to configure a Client. It must not be
// modified after having been passed to an SSH function.
type ClientConfig struct {
@ -188,10 +202,12 @@ type ClientConfig struct {
// be used during authentication.
Auth []AuthMethod
// HostKeyCallback, if not nil, is called during the cryptographic
// handshake to validate the server's host key. A nil HostKeyCallback
// implies that all host keys are accepted.
HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
// HostKeyCallback is called during the cryptographic
// handshake to validate the server's host key. The client
// configuration must supply this callback for the connection
// to succeed. The functions InsecureIgnoreHostKey or
// FixedHostKey can be used for simplistic host key checks.
HostKeyCallback HostKeyCallback
// ClientVersion contains the version identification string that will
// be used for the connection. If empty, a reasonable default is used.
@ -209,3 +225,33 @@ type ClientConfig struct {
// A Timeout of zero means no timeout.
Timeout time.Duration
}
// InsecureIgnoreHostKey returns a function that can be used for
// ClientConfig.HostKeyCallback to accept any host key. It should
// not be used for production code.
func InsecureIgnoreHostKey() HostKeyCallback {
return func(hostname string, remote net.Addr, key PublicKey) error {
return nil
}
}
type fixedHostKey struct {
key PublicKey
}
func (f *fixedHostKey) check(hostname string, remote net.Addr, key PublicKey) error {
if f.key == nil {
return fmt.Errorf("ssh: required host key was nil")
}
if !bytes.Equal(key.Marshal(), f.key.Marshal()) {
return fmt.Errorf("ssh: host key mismatch")
}
return nil
}
// FixedHostKey returns a function for use in
// ClientConfig.HostKeyCallback to accept only a specific host key.
func FixedHostKey(key PublicKey) HostKeyCallback {
hk := &fixedHostKey{key}
return hk.check
}

View File

@ -179,31 +179,26 @@ func (cb publicKeyCallback) method() string {
}
func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
// Authentication is performed in two stages. The first stage sends an
// enquiry to test if each key is acceptable to the remote. The second
// stage attempts to authenticate with the valid keys obtained in the
// first stage.
// Authentication is performed by sending an enquiry to test if a key is
// acceptable to the remote. If the key is acceptable, the client will
// attempt to authenticate with the valid key. If not the client will repeat
// the process with the remaining keys.
signers, err := cb()
if err != nil {
return false, nil, err
}
var validKeys []Signer
for _, signer := range signers {
if ok, err := validateKey(signer.PublicKey(), user, c); ok {
validKeys = append(validKeys, signer)
} else {
if err != nil {
return false, nil, err
}
}
}
// methods that may continue if this auth is not successful.
var methods []string
for _, signer := range validKeys {
pub := signer.PublicKey()
for _, signer := range signers {
ok, err := validateKey(signer.PublicKey(), user, c)
if err != nil {
return false, nil, err
}
if !ok {
continue
}
pub := signer.PublicKey()
pubKey := pub.Marshal()
sign, err := signer.Sign(rand, buildDataSignedForAuth(session, userAuthRequestMsg{
User: user,
@ -236,13 +231,29 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
if err != nil {
return false, nil, err
}
if success {
// If authentication succeeds or the list of available methods does not
// contain the "publickey" method, do not attempt to authenticate with any
// other keys. According to RFC 4252 Section 7, the latter can occur when
// additional authentication methods are required.
if success || !containsMethod(methods, cb.method()) {
return success, methods, err
}
}
return false, methods, nil
}
func containsMethod(methods []string, method string) bool {
for _, m := range methods {
if m == method {
return true
}
}
return false
}
// validateKey validates the key provided is acceptable to the server.
func validateKey(key PublicKey, user string, c packetConn) (bool, error) {
pubKey := key.Marshal()

View File

@ -9,6 +9,7 @@ import (
"crypto/rand"
"fmt"
"io"
"math"
"sync"
_ "crypto/sha1"
@ -40,7 +41,7 @@ var supportedKexAlgos = []string{
kexAlgoDH14SHA1, kexAlgoDH1SHA1,
}
// supportedKexAlgos specifies the supported host-key algorithms (i.e. methods
// supportedHostKeyAlgos specifies the supported host-key algorithms (i.e. methods
// of authenticating servers) in preference order.
var supportedHostKeyAlgos = []string{
CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
@ -186,7 +187,7 @@ type Config struct {
// The maximum number of bytes sent or received after which a
// new key is negotiated. It must be at least 256. If
// unspecified, 1 gigabyte is used.
// unspecified, a size suitable for the chosen cipher is used.
RekeyThreshold uint64
// The allowed key exchanges algorithms. If unspecified then a
@ -230,11 +231,12 @@ func (c *Config) SetDefaults() {
}
if c.RekeyThreshold == 0 {
// RFC 4253, section 9 suggests rekeying after 1G.
c.RekeyThreshold = 1 << 30
}
if c.RekeyThreshold < minRekeyThreshold {
// cipher specific default
} else if c.RekeyThreshold < minRekeyThreshold {
c.RekeyThreshold = minRekeyThreshold
} else if c.RekeyThreshold >= math.MaxInt64 {
// Avoid weirdness if somebody uses -1 as a threshold.
c.RekeyThreshold = math.MaxInt64
}
}

View File

@ -14,5 +14,8 @@ others.
References:
[PROTOCOL.certkeys]: http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.certkeys?rev=HEAD
[SSH-PARAMETERS]: http://www.iana.org/assignments/ssh-parameters/ssh-parameters.xml#ssh-parameters-1
This package does not fall under the stability promise of the Go language itself,
so its API may be changed when pressing needs arise.
*/
package ssh // import "golang.org/x/crypto/ssh"

View File

@ -74,7 +74,7 @@ type handshakeTransport struct {
startKex chan *pendingKex
// data for host key checking
hostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
hostKeyCallback HostKeyCallback
dialAddress string
remoteAddr net.Addr
@ -107,6 +107,8 @@ func newHandshakeTransport(conn keyingTransport, config *Config, clientVersion,
config: config,
}
t.resetReadThresholds()
t.resetWriteThresholds()
// We always start with a mandatory key exchange.
t.requestKex <- struct{}{}
@ -237,6 +239,17 @@ func (t *handshakeTransport) requestKeyExchange() {
}
}
func (t *handshakeTransport) resetWriteThresholds() {
t.writePacketsLeft = packetRekeyThreshold
if t.config.RekeyThreshold > 0 {
t.writeBytesLeft = int64(t.config.RekeyThreshold)
} else if t.algorithms != nil {
t.writeBytesLeft = t.algorithms.w.rekeyBytes()
} else {
t.writeBytesLeft = 1 << 30
}
}
func (t *handshakeTransport) kexLoop() {
write:
@ -285,12 +298,8 @@ write:
t.writeError = err
t.sentInitPacket = nil
t.sentInitMsg = nil
t.writePacketsLeft = packetRekeyThreshold
if t.config.RekeyThreshold > 0 {
t.writeBytesLeft = int64(t.config.RekeyThreshold)
} else if t.algorithms != nil {
t.writeBytesLeft = t.algorithms.w.rekeyBytes()
}
t.resetWriteThresholds()
// we have completed the key exchange. Since the
// reader is still blocked, it is safe to clear out
@ -344,6 +353,17 @@ write:
// key exchange itself.
const packetRekeyThreshold = (1 << 31)
func (t *handshakeTransport) resetReadThresholds() {
t.readPacketsLeft = packetRekeyThreshold
if t.config.RekeyThreshold > 0 {
t.readBytesLeft = int64(t.config.RekeyThreshold)
} else if t.algorithms != nil {
t.readBytesLeft = t.algorithms.r.rekeyBytes()
} else {
t.readBytesLeft = 1 << 30
}
}
func (t *handshakeTransport) readOnePacket(first bool) ([]byte, error) {
p, err := t.conn.readPacket()
if err != nil {
@ -391,12 +411,7 @@ func (t *handshakeTransport) readOnePacket(first bool) ([]byte, error) {
return nil, err
}
t.readPacketsLeft = packetRekeyThreshold
if t.config.RekeyThreshold > 0 {
t.readBytesLeft = int64(t.config.RekeyThreshold)
} else {
t.readBytesLeft = t.algorithms.r.rekeyBytes()
}
t.resetReadThresholds()
// By default, a key exchange is hidden from higher layers by
// translating it into msgIgnore.
@ -574,7 +589,9 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
}
result.SessionID = t.sessionID
t.conn.prepareKeyChange(t.algorithms, result)
if err := t.conn.prepareKeyChange(t.algorithms, result); err != nil {
return err
}
if err = t.conn.writePacket([]byte{msgNewKeys}); err != nil {
return err
}
@ -614,11 +631,9 @@ func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *
return nil, err
}
if t.hostKeyCallback != nil {
err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
if err != nil {
return nil, err
}
err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
if err != nil {
return nil, err
}
return result, nil

View File

@ -824,7 +824,7 @@ func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) {
// Implemented based on the documentation at
// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key
func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) {
magic := append([]byte("openssh-key-v1"), 0)
if !bytes.Equal(magic, key[0:len(magic)]) {
return nil, errors.New("ssh: invalid openssh private key format")
@ -844,14 +844,15 @@ func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
return nil, err
}
if w.KdfName != "none" || w.CipherName != "none" {
return nil, errors.New("ssh: cannot decode encrypted private keys")
}
pk1 := struct {
Check1 uint32
Check2 uint32
Keytype string
Pub []byte
Priv []byte
Comment string
Pad []byte `ssh:"rest"`
Rest []byte `ssh:"rest"`
}{}
if err := Unmarshal(w.PrivKeyBlock, &pk1); err != nil {
@ -862,24 +863,75 @@ func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
return nil, errors.New("ssh: checkint mismatch")
}
// we only handle ed25519 keys currently
if pk1.Keytype != KeyAlgoED25519 {
// we only handle ed25519 and rsa keys currently
switch pk1.Keytype {
case KeyAlgoRSA:
// https://github.com/openssh/openssh-portable/blob/master/sshkey.c#L2760-L2773
key := struct {
N *big.Int
E *big.Int
D *big.Int
Iqmp *big.Int
P *big.Int
Q *big.Int
Comment string
Pad []byte `ssh:"rest"`
}{}
if err := Unmarshal(pk1.Rest, &key); err != nil {
return nil, err
}
for i, b := range key.Pad {
if int(b) != i+1 {
return nil, errors.New("ssh: padding not as expected")
}
}
pk := &rsa.PrivateKey{
PublicKey: rsa.PublicKey{
N: key.N,
E: int(key.E.Int64()),
},
D: key.D,
Primes: []*big.Int{key.P, key.Q},
}
if err := pk.Validate(); err != nil {
return nil, err
}
pk.Precompute()
return pk, nil
case KeyAlgoED25519:
key := struct {
Pub []byte
Priv []byte
Comment string
Pad []byte `ssh:"rest"`
}{}
if err := Unmarshal(pk1.Rest, &key); err != nil {
return nil, err
}
if len(key.Priv) != ed25519.PrivateKeySize {
return nil, errors.New("ssh: private key unexpected length")
}
for i, b := range key.Pad {
if int(b) != i+1 {
return nil, errors.New("ssh: padding not as expected")
}
}
pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
copy(pk, key.Priv)
return &pk, nil
default:
return nil, errors.New("ssh: unhandled key type")
}
for i, b := range pk1.Pad {
if int(b) != i+1 {
return nil, errors.New("ssh: padding not as expected")
}
}
if len(pk1.Priv) != ed25519.PrivateKeySize {
return nil, errors.New("ssh: private key unexpected length")
}
pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
copy(pk, pk1.Priv)
return &pk, nil
}
// FingerprintLegacyMD5 returns the user presentation of the key's

View File

@ -45,6 +45,12 @@ type ServerConfig struct {
// authenticating.
NoClientAuth bool
// MaxAuthTries specifies the maximum number of authentication attempts
// permitted per connection. If set to a negative number, the number of
// attempts are unlimited. If set to zero, the number of attempts are limited
// to 6.
MaxAuthTries int
// PasswordCallback, if non-nil, is called when a user
// attempts to authenticate using a password.
PasswordCallback func(conn ConnMetadata, password []byte) (*Permissions, error)
@ -141,6 +147,10 @@ type ServerConn struct {
// Request and NewChannel channels must be serviced, or the connection
// will hang.
func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewChannel, <-chan *Request, error) {
if config.MaxAuthTries == 0 {
config.MaxAuthTries = 6
}
fullConf := *config
fullConf.SetDefaults()
s := &connection{
@ -267,8 +277,23 @@ func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, err
var cache pubKeyCache
var perms *Permissions
authFailures := 0
userAuthLoop:
for {
if authFailures >= config.MaxAuthTries && config.MaxAuthTries > 0 {
discMsg := &disconnectMsg{
Reason: 2,
Message: "too many authentication failures",
}
if err := s.transport.writePacket(Marshal(discMsg)); err != nil {
return nil, err
}
return nil, discMsg
}
var userAuthReq userAuthRequestMsg
if packet, err := s.transport.readPacket(); err != nil {
return nil, err
@ -289,6 +314,11 @@ userAuthLoop:
if config.NoClientAuth {
authErr = nil
}
// allow initial attempt of 'none' without penalty
if authFailures == 0 {
authFailures--
}
case "password":
if config.PasswordCallback == nil {
authErr = errors.New("ssh: password auth not configured")
@ -360,6 +390,7 @@ userAuthLoop:
if isQuery {
// The client can query if the given public key
// would be okay.
if len(payload) > 0 {
return nil, parseError(msgUserAuthRequest)
}
@ -409,6 +440,8 @@ userAuthLoop:
break userAuthLoop
}
authFailures++
var failureMsg userAuthFailureMsg
if config.PasswordCallback != nil {
failureMsg.Methods = append(failureMsg.Methods, "password")

115
vendor/golang.org/x/crypto/ssh/streamlocal.go generated vendored Normal file
View File

@ -0,0 +1,115 @@
package ssh
import (
"errors"
"io"
"net"
)
// streamLocalChannelOpenDirectMsg is a struct used for SSH_MSG_CHANNEL_OPEN message
// with "direct-streamlocal@openssh.com" string.
//
// See openssh-portable/PROTOCOL, section 2.4. connection: Unix domain socket forwarding
// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL#L235
type streamLocalChannelOpenDirectMsg struct {
socketPath string
reserved0 string
reserved1 uint32
}
// forwardedStreamLocalPayload is a struct used for SSH_MSG_CHANNEL_OPEN message
// with "forwarded-streamlocal@openssh.com" string.
type forwardedStreamLocalPayload struct {
SocketPath string
Reserved0 string
}
// streamLocalChannelForwardMsg is a struct used for SSH2_MSG_GLOBAL_REQUEST message
// with "streamlocal-forward@openssh.com"/"cancel-streamlocal-forward@openssh.com" string.
type streamLocalChannelForwardMsg struct {
socketPath string
}
// ListenUnix is similar to ListenTCP but uses a Unix domain socket.
func (c *Client) ListenUnix(socketPath string) (net.Listener, error) {
m := streamLocalChannelForwardMsg{
socketPath,
}
// send message
ok, _, err := c.SendRequest("streamlocal-forward@openssh.com", true, Marshal(&m))
if err != nil {
return nil, err
}
if !ok {
return nil, errors.New("ssh: streamlocal-forward@openssh.com request denied by peer")
}
ch := c.forwards.add(&net.UnixAddr{Name: socketPath, Net: "unix"})
return &unixListener{socketPath, c, ch}, nil
}
func (c *Client) dialStreamLocal(socketPath string) (Channel, error) {
msg := streamLocalChannelOpenDirectMsg{
socketPath: socketPath,
}
ch, in, err := c.OpenChannel("direct-streamlocal@openssh.com", Marshal(&msg))
if err != nil {
return nil, err
}
go DiscardRequests(in)
return ch, err
}
type unixListener struct {
socketPath string
conn *Client
in <-chan forward
}
// Accept waits for and returns the next connection to the listener.
func (l *unixListener) Accept() (net.Conn, error) {
s, ok := <-l.in
if !ok {
return nil, io.EOF
}
ch, incoming, err := s.newCh.Accept()
if err != nil {
return nil, err
}
go DiscardRequests(incoming)
return &chanConn{
Channel: ch,
laddr: &net.UnixAddr{
Name: l.socketPath,
Net: "unix",
},
raddr: &net.UnixAddr{
Name: "@",
Net: "unix",
},
}, nil
}
// Close closes the listener.
func (l *unixListener) Close() error {
// this also closes the listener.
l.conn.forwards.remove(&net.UnixAddr{Name: l.socketPath, Net: "unix"})
m := streamLocalChannelForwardMsg{
l.socketPath,
}
ok, _, err := l.conn.SendRequest("cancel-streamlocal-forward@openssh.com", true, Marshal(&m))
if err == nil && !ok {
err = errors.New("ssh: cancel-streamlocal-forward@openssh.com failed")
}
return err
}
// Addr returns the listener's network address.
func (l *unixListener) Addr() net.Addr {
return &net.UnixAddr{
Name: l.socketPath,
Net: "unix",
}
}

View File

@ -20,12 +20,20 @@ import (
// addr. Incoming connections will be available by calling Accept on
// the returned net.Listener. The listener must be serviced, or the
// SSH connection may hang.
// N must be "tcp", "tcp4", "tcp6", or "unix".
func (c *Client) Listen(n, addr string) (net.Listener, error) {
laddr, err := net.ResolveTCPAddr(n, addr)
if err != nil {
return nil, err
switch n {
case "tcp", "tcp4", "tcp6":
laddr, err := net.ResolveTCPAddr(n, addr)
if err != nil {
return nil, err
}
return c.ListenTCP(laddr)
case "unix":
return c.ListenUnix(addr)
default:
return nil, fmt.Errorf("ssh: unsupported protocol: %s", n)
}
return c.ListenTCP(laddr)
}
// Automatic port allocation is broken with OpenSSH before 6.0. See
@ -116,7 +124,7 @@ func (c *Client) ListenTCP(laddr *net.TCPAddr) (net.Listener, error) {
}
// Register this forward, using the port number we obtained.
ch := c.forwards.add(*laddr)
ch := c.forwards.add(laddr)
return &tcpListener{laddr, c, ch}, nil
}
@ -131,7 +139,7 @@ type forwardList struct {
// forwardEntry represents an established mapping of a laddr on a
// remote ssh server to a channel connected to a tcpListener.
type forwardEntry struct {
laddr net.TCPAddr
laddr net.Addr
c chan forward
}
@ -139,16 +147,16 @@ type forwardEntry struct {
// arguments to add/remove/lookup should be address as specified in
// the original forward-request.
type forward struct {
newCh NewChannel // the ssh client channel underlying this forward
raddr *net.TCPAddr // the raddr of the incoming connection
newCh NewChannel // the ssh client channel underlying this forward
raddr net.Addr // the raddr of the incoming connection
}
func (l *forwardList) add(addr net.TCPAddr) chan forward {
func (l *forwardList) add(addr net.Addr) chan forward {
l.Lock()
defer l.Unlock()
f := forwardEntry{
addr,
make(chan forward, 1),
laddr: addr,
c: make(chan forward, 1),
}
l.entries = append(l.entries, f)
return f.c
@ -176,44 +184,69 @@ func parseTCPAddr(addr string, port uint32) (*net.TCPAddr, error) {
func (l *forwardList) handleChannels(in <-chan NewChannel) {
for ch := range in {
var payload forwardedTCPPayload
if err := Unmarshal(ch.ExtraData(), &payload); err != nil {
ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
continue
}
var (
laddr net.Addr
raddr net.Addr
err error
)
switch channelType := ch.ChannelType(); channelType {
case "forwarded-tcpip":
var payload forwardedTCPPayload
if err = Unmarshal(ch.ExtraData(), &payload); err != nil {
ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
continue
}
// RFC 4254 section 7.2 specifies that incoming
// addresses should list the address, in string
// format. It is implied that this should be an IP
// address, as it would be impossible to connect to it
// otherwise.
laddr, err := parseTCPAddr(payload.Addr, payload.Port)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
raddr, err := parseTCPAddr(payload.OriginAddr, payload.OriginPort)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
// RFC 4254 section 7.2 specifies that incoming
// addresses should list the address, in string
// format. It is implied that this should be an IP
// address, as it would be impossible to connect to it
// otherwise.
laddr, err = parseTCPAddr(payload.Addr, payload.Port)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
raddr, err = parseTCPAddr(payload.OriginAddr, payload.OriginPort)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
if ok := l.forward(*laddr, *raddr, ch); !ok {
case "forwarded-streamlocal@openssh.com":
var payload forwardedStreamLocalPayload
if err = Unmarshal(ch.ExtraData(), &payload); err != nil {
ch.Reject(ConnectionFailed, "could not parse forwarded-streamlocal@openssh.com payload: "+err.Error())
continue
}
laddr = &net.UnixAddr{
Name: payload.SocketPath,
Net: "unix",
}
raddr = &net.UnixAddr{
Name: "@",
Net: "unix",
}
default:
panic(fmt.Errorf("ssh: unknown channel type %s", channelType))
}
if ok := l.forward(laddr, raddr, ch); !ok {
// Section 7.2, implementations MUST reject spurious incoming
// connections.
ch.Reject(Prohibited, "no forward for address")
continue
}
}
}
// remove removes the forward entry, and the channel feeding its
// listener.
func (l *forwardList) remove(addr net.TCPAddr) {
func (l *forwardList) remove(addr net.Addr) {
l.Lock()
defer l.Unlock()
for i, f := range l.entries {
if addr.IP.Equal(f.laddr.IP) && addr.Port == f.laddr.Port {
if addr.Network() == f.laddr.Network() && addr.String() == f.laddr.String() {
l.entries = append(l.entries[:i], l.entries[i+1:]...)
close(f.c)
return
@ -231,12 +264,12 @@ func (l *forwardList) closeAll() {
l.entries = nil
}
func (l *forwardList) forward(laddr, raddr net.TCPAddr, ch NewChannel) bool {
func (l *forwardList) forward(laddr, raddr net.Addr, ch NewChannel) bool {
l.Lock()
defer l.Unlock()
for _, f := range l.entries {
if laddr.IP.Equal(f.laddr.IP) && laddr.Port == f.laddr.Port {
f.c <- forward{ch, &raddr}
if laddr.Network() == f.laddr.Network() && laddr.String() == f.laddr.String() {
f.c <- forward{newCh: ch, raddr: raddr}
return true
}
}
@ -262,7 +295,7 @@ func (l *tcpListener) Accept() (net.Conn, error) {
}
go DiscardRequests(incoming)
return &tcpChanConn{
return &chanConn{
Channel: ch,
laddr: l.laddr,
raddr: s.raddr,
@ -277,7 +310,7 @@ func (l *tcpListener) Close() error {
}
// this also closes the listener.
l.conn.forwards.remove(*l.laddr)
l.conn.forwards.remove(l.laddr)
ok, _, err := l.conn.SendRequest("cancel-tcpip-forward", true, Marshal(&m))
if err == nil && !ok {
err = errors.New("ssh: cancel-tcpip-forward failed")
@ -293,29 +326,52 @@ func (l *tcpListener) Addr() net.Addr {
// Dial initiates a connection to the addr from the remote host.
// The resulting connection has a zero LocalAddr() and RemoteAddr().
func (c *Client) Dial(n, addr string) (net.Conn, error) {
// Parse the address into host and numeric port.
host, portString, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
var ch Channel
switch n {
case "tcp", "tcp4", "tcp6":
// Parse the address into host and numeric port.
host, portString, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
port, err := strconv.ParseUint(portString, 10, 16)
if err != nil {
return nil, err
}
ch, err = c.dial(net.IPv4zero.String(), 0, host, int(port))
if err != nil {
return nil, err
}
// Use a zero address for local and remote address.
zeroAddr := &net.TCPAddr{
IP: net.IPv4zero,
Port: 0,
}
return &chanConn{
Channel: ch,
laddr: zeroAddr,
raddr: zeroAddr,
}, nil
case "unix":
var err error
ch, err = c.dialStreamLocal(addr)
if err != nil {
return nil, err
}
return &chanConn{
Channel: ch,
laddr: &net.UnixAddr{
Name: "@",
Net: "unix",
},
raddr: &net.UnixAddr{
Name: addr,
Net: "unix",
},
}, nil
default:
return nil, fmt.Errorf("ssh: unsupported protocol: %s", n)
}
port, err := strconv.ParseUint(portString, 10, 16)
if err != nil {
return nil, err
}
// Use a zero address for local and remote address.
zeroAddr := &net.TCPAddr{
IP: net.IPv4zero,
Port: 0,
}
ch, err := c.dial(net.IPv4zero.String(), 0, host, int(port))
if err != nil {
return nil, err
}
return &tcpChanConn{
Channel: ch,
laddr: zeroAddr,
raddr: zeroAddr,
}, nil
}
// DialTCP connects to the remote address raddr on the network net,
@ -332,7 +388,7 @@ func (c *Client) DialTCP(n string, laddr, raddr *net.TCPAddr) (net.Conn, error)
if err != nil {
return nil, err
}
return &tcpChanConn{
return &chanConn{
Channel: ch,
laddr: laddr,
raddr: raddr,
@ -366,26 +422,26 @@ type tcpChan struct {
Channel // the backing channel
}
// tcpChanConn fulfills the net.Conn interface without
// chanConn fulfills the net.Conn interface without
// the tcpChan having to hold laddr or raddr directly.
type tcpChanConn struct {
type chanConn struct {
Channel
laddr, raddr net.Addr
}
// LocalAddr returns the local network address.
func (t *tcpChanConn) LocalAddr() net.Addr {
func (t *chanConn) LocalAddr() net.Addr {
return t.laddr
}
// RemoteAddr returns the remote network address.
func (t *tcpChanConn) RemoteAddr() net.Addr {
func (t *chanConn) RemoteAddr() net.Addr {
return t.raddr
}
// SetDeadline sets the read and write deadlines associated
// with the connection.
func (t *tcpChanConn) SetDeadline(deadline time.Time) error {
func (t *chanConn) SetDeadline(deadline time.Time) error {
if err := t.SetReadDeadline(deadline); err != nil {
return err
}
@ -396,12 +452,14 @@ func (t *tcpChanConn) SetDeadline(deadline time.Time) error {
// A zero value for t means Read will not time out.
// After the deadline, the error from Read will implement net.Error
// with Timeout() == true.
func (t *tcpChanConn) SetReadDeadline(deadline time.Time) error {
func (t *chanConn) SetReadDeadline(deadline time.Time) error {
// for compatibility with previous version,
// the error message contains "tcpChan"
return errors.New("ssh: tcpChan: deadline not supported")
}
// SetWriteDeadline exists to satisfy the net.Conn interface
// but is not implemented by this type. It always returns an error.
func (t *tcpChanConn) SetWriteDeadline(deadline time.Time) error {
func (t *chanConn) SetWriteDeadline(deadline time.Time) error {
return errors.New("ssh: tcpChan: deadline not supported")
}

View File

@ -14,14 +14,12 @@ import (
// State contains the state of a terminal.
type State struct {
termios syscall.Termios
state *unix.Termios
}
// IsTerminal returns true if the given file descriptor is a terminal.
func IsTerminal(fd int) bool {
// see: http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libbc/libc/gen/common/isatty.c
var termio unix.Termio
err := unix.IoctlSetTermio(fd, unix.TCGETA, &termio)
_, err := unix.IoctlGetTermio(fd, unix.TCGETA)
return err == nil
}
@ -71,3 +69,60 @@ func ReadPassword(fd int) ([]byte, error) {
return ret, nil
}
// MakeRaw puts the terminal connected to the given file descriptor into raw
// mode and returns the previous state of the terminal so that it can be
// restored.
// see http://cr.illumos.org/~webrev/andy_js/1060/
func MakeRaw(fd int) (*State, error) {
oldTermiosPtr, err := unix.IoctlGetTermios(fd, unix.TCGETS)
if err != nil {
return nil, err
}
oldTermios := *oldTermiosPtr
newTermios := oldTermios
newTermios.Iflag &^= syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK | syscall.ISTRIP | syscall.INLCR | syscall.IGNCR | syscall.ICRNL | syscall.IXON
newTermios.Oflag &^= syscall.OPOST
newTermios.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG | syscall.IEXTEN
newTermios.Cflag &^= syscall.CSIZE | syscall.PARENB
newTermios.Cflag |= syscall.CS8
newTermios.Cc[unix.VMIN] = 1
newTermios.Cc[unix.VTIME] = 0
if err := unix.IoctlSetTermios(fd, unix.TCSETS, &newTermios); err != nil {
return nil, err
}
return &State{
state: oldTermiosPtr,
}, nil
}
// Restore restores the terminal connected to the given file descriptor to a
// previous state.
func Restore(fd int, oldState *State) error {
return unix.IoctlSetTermios(fd, unix.TCSETS, oldState.state)
}
// GetState returns the current state of a terminal which may be useful to
// restore the terminal after a signal.
func GetState(fd int) (*State, error) {
oldTermiosPtr, err := unix.IoctlGetTermios(fd, unix.TCGETS)
if err != nil {
return nil, err
}
return &State{
state: oldTermiosPtr,
}, nil
}
// GetSize returns the dimensions of the given terminal.
func GetSize(fd int) (width, height int, err error) {
ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
if err != nil {
return 0, 0, err
}
return int(ws.Col), int(ws.Row), nil
}