dex/vendor/golang.org/x/crypto/ssh/handshake_test.go

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2016-07-26 01:30:28 +05:30
// 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 (
"bytes"
"crypto/rand"
"errors"
"fmt"
"net"
"reflect"
"runtime"
"strings"
"sync"
"testing"
)
type testChecker struct {
calls []string
}
func (t *testChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
if dialAddr == "bad" {
return fmt.Errorf("dialAddr is bad")
}
if tcpAddr, ok := addr.(*net.TCPAddr); !ok || tcpAddr == nil {
return fmt.Errorf("testChecker: got %T want *net.TCPAddr", addr)
}
t.calls = append(t.calls, fmt.Sprintf("%s %v %s %x", dialAddr, addr, key.Type(), key.Marshal()))
return nil
}
// netPipe is analogous to net.Pipe, but it uses a real net.Conn, and
// therefore is buffered (net.Pipe deadlocks if both sides start with
// a write.)
func netPipe() (net.Conn, net.Conn, error) {
listener, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
return nil, nil, err
}
defer listener.Close()
c1, err := net.Dial("tcp", listener.Addr().String())
if err != nil {
return nil, nil, err
}
c2, err := listener.Accept()
if err != nil {
c1.Close()
return nil, nil, err
}
return c1, c2, nil
}
func handshakePair(clientConf *ClientConfig, addr string) (client *handshakeTransport, server *handshakeTransport, err error) {
a, b, err := netPipe()
if err != nil {
return nil, nil, err
}
trC := newTransport(a, rand.Reader, true)
trS := newTransport(b, rand.Reader, false)
clientConf.SetDefaults()
v := []byte("version")
client = newClientTransport(trC, v, v, clientConf, addr, a.RemoteAddr())
serverConf := &ServerConfig{}
serverConf.AddHostKey(testSigners["ecdsa"])
serverConf.AddHostKey(testSigners["rsa"])
serverConf.SetDefaults()
server = newServerTransport(trS, v, v, serverConf)
return client, server, nil
}
func TestHandshakeBasic(t *testing.T) {
if runtime.GOOS == "plan9" {
t.Skip("see golang.org/issue/7237")
}
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
go func() {
// Client writes a bunch of stuff, and does a key
// change in the middle. This should not confuse the
// handshake in progress
for i := 0; i < 10; i++ {
p := []byte{msgRequestSuccess, byte(i)}
if err := trC.writePacket(p); err != nil {
t.Fatalf("sendPacket: %v", err)
}
if i == 5 {
// halfway through, we request a key change.
err := trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Fatalf("sendKexInit: %v", err)
}
}
}
trC.Close()
}()
// Server checks that client messages come in cleanly
i := 0
for {
p, err := trS.readPacket()
if err != nil {
break
}
if p[0] == msgNewKeys {
continue
}
want := []byte{msgRequestSuccess, byte(i)}
if bytes.Compare(p, want) != 0 {
t.Errorf("message %d: got %q, want %q", i, p, want)
}
i++
}
if i != 10 {
t.Errorf("received %d messages, want 10.", i)
}
// If all went well, we registered exactly 1 key change.
if len(checker.calls) != 1 {
t.Fatalf("got %d host key checks, want 1", len(checker.calls))
}
pub := testSigners["ecdsa"].PublicKey()
want := fmt.Sprintf("%s %v %s %x", "addr", trC.remoteAddr, pub.Type(), pub.Marshal())
if want != checker.calls[0] {
t.Errorf("got %q want %q for host key check", checker.calls[0], want)
}
}
func TestHandshakeError(t *testing.T) {
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "bad")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
// send a packet
packet := []byte{msgRequestSuccess, 42}
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
// Now request a key change.
err = trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Errorf("sendKexInit: %v", err)
}
// the key change will fail, and afterwards we can't write.
if err := trC.writePacket([]byte{msgRequestSuccess, 43}); err == nil {
t.Errorf("writePacket after botched rekey succeeded.")
}
readback, err := trS.readPacket()
if err != nil {
t.Fatalf("server closed too soon: %v", err)
}
if bytes.Compare(readback, packet) != 0 {
t.Errorf("got %q want %q", readback, packet)
}
readback, err = trS.readPacket()
if err == nil {
t.Errorf("got a message %q after failed key change", readback)
}
}
func TestForceFirstKex(t *testing.T) {
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
trC.writePacket(Marshal(&serviceRequestMsg{serviceUserAuth}))
// We setup the initial key exchange, but the remote side
// tries to send serviceRequestMsg in cleartext, which is
// disallowed.
err = trS.sendKexInit(firstKeyExchange)
if err == nil {
t.Errorf("server first kex init should reject unexpected packet")
}
}
func TestHandshakeTwice(t *testing.T) {
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
// Both sides should ask for the first key exchange first.
err = trS.sendKexInit(firstKeyExchange)
if err != nil {
t.Errorf("server sendKexInit: %v", err)
}
err = trC.sendKexInit(firstKeyExchange)
if err != nil {
t.Errorf("client sendKexInit: %v", err)
}
sent := 0
// send a packet
packet := make([]byte, 5)
packet[0] = msgRequestSuccess
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
sent++
// Send another packet. Use a fresh one, since writePacket destroys.
packet = make([]byte, 5)
packet[0] = msgRequestSuccess
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
sent++
// 2nd key change.
err = trC.sendKexInit(subsequentKeyExchange)
if err != nil {
t.Errorf("sendKexInit: %v", err)
}
packet = make([]byte, 5)
packet[0] = msgRequestSuccess
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
sent++
packet = make([]byte, 5)
packet[0] = msgRequestSuccess
for i := 0; i < sent; i++ {
msg, err := trS.readPacket()
if err != nil {
t.Fatalf("server closed too soon: %v", err)
}
if bytes.Compare(msg, packet) != 0 {
t.Errorf("packet %d: got %q want %q", i, msg, packet)
}
}
if len(checker.calls) != 2 {
t.Errorf("got %d key changes, want 2", len(checker.calls))
}
}
func TestHandshakeAutoRekeyWrite(t *testing.T) {
checker := &testChecker{}
clientConf := &ClientConfig{HostKeyCallback: checker.Check}
clientConf.RekeyThreshold = 500
trC, trS, err := handshakePair(clientConf, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
for i := 0; i < 5; i++ {
packet := make([]byte, 251)
packet[0] = msgRequestSuccess
if err := trC.writePacket(packet); err != nil {
t.Errorf("writePacket: %v", err)
}
}
j := 0
for ; j < 5; j++ {
_, err := trS.readPacket()
if err != nil {
break
}
}
if j != 5 {
t.Errorf("got %d, want 5 messages", j)
}
if len(checker.calls) != 2 {
t.Errorf("got %d key changes, wanted 2", len(checker.calls))
}
}
type syncChecker struct {
called chan int
}
func (t *syncChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
t.called <- 1
return nil
}
func TestHandshakeAutoRekeyRead(t *testing.T) {
sync := &syncChecker{make(chan int, 2)}
clientConf := &ClientConfig{
HostKeyCallback: sync.Check,
}
clientConf.RekeyThreshold = 500
trC, trS, err := handshakePair(clientConf, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
packet := make([]byte, 501)
packet[0] = msgRequestSuccess
if err := trS.writePacket(packet); err != nil {
t.Fatalf("writePacket: %v", err)
}
// While we read out the packet, a key change will be
// initiated.
if _, err := trC.readPacket(); err != nil {
t.Fatalf("readPacket(client): %v", err)
}
<-sync.called
}
// errorKeyingTransport generates errors after a given number of
// read/write operations.
type errorKeyingTransport struct {
packetConn
readLeft, writeLeft int
}
func (n *errorKeyingTransport) prepareKeyChange(*algorithms, *kexResult) error {
return nil
}
func (n *errorKeyingTransport) getSessionID() []byte {
return nil
}
func (n *errorKeyingTransport) writePacket(packet []byte) error {
if n.writeLeft == 0 {
n.Close()
return errors.New("barf")
}
n.writeLeft--
return n.packetConn.writePacket(packet)
}
func (n *errorKeyingTransport) readPacket() ([]byte, error) {
if n.readLeft == 0 {
n.Close()
return nil, errors.New("barf")
}
n.readLeft--
return n.packetConn.readPacket()
}
func TestHandshakeErrorHandlingRead(t *testing.T) {
for i := 0; i < 20; i++ {
testHandshakeErrorHandlingN(t, i, -1)
}
}
func TestHandshakeErrorHandlingWrite(t *testing.T) {
for i := 0; i < 20; i++ {
testHandshakeErrorHandlingN(t, -1, i)
}
}
// testHandshakeErrorHandlingN runs handshakes, injecting errors. If
// handshakeTransport deadlocks, the go runtime will detect it and
// panic.
func testHandshakeErrorHandlingN(t *testing.T, readLimit, writeLimit int) {
msg := Marshal(&serviceRequestMsg{strings.Repeat("x", int(minRekeyThreshold)/4)})
a, b := memPipe()
defer a.Close()
defer b.Close()
key := testSigners["ecdsa"]
serverConf := Config{RekeyThreshold: minRekeyThreshold}
serverConf.SetDefaults()
serverConn := newHandshakeTransport(&errorKeyingTransport{a, readLimit, writeLimit}, &serverConf, []byte{'a'}, []byte{'b'})
serverConn.hostKeys = []Signer{key}
go serverConn.readLoop()
clientConf := Config{RekeyThreshold: 10 * minRekeyThreshold}
clientConf.SetDefaults()
clientConn := newHandshakeTransport(&errorKeyingTransport{b, -1, -1}, &clientConf, []byte{'a'}, []byte{'b'})
clientConn.hostKeyAlgorithms = []string{key.PublicKey().Type()}
go clientConn.readLoop()
var wg sync.WaitGroup
wg.Add(4)
for _, hs := range []packetConn{serverConn, clientConn} {
go func(c packetConn) {
for {
err := c.writePacket(msg)
if err != nil {
break
}
}
wg.Done()
}(hs)
go func(c packetConn) {
for {
_, err := c.readPacket()
if err != nil {
break
}
}
wg.Done()
}(hs)
}
wg.Wait()
}
func TestDisconnect(t *testing.T) {
if runtime.GOOS == "plan9" {
t.Skip("see golang.org/issue/7237")
}
checker := &testChecker{}
trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
if err != nil {
t.Fatalf("handshakePair: %v", err)
}
defer trC.Close()
defer trS.Close()
trC.writePacket([]byte{msgRequestSuccess, 0, 0})
errMsg := &disconnectMsg{
Reason: 42,
Message: "such is life",
}
trC.writePacket(Marshal(errMsg))
trC.writePacket([]byte{msgRequestSuccess, 0, 0})
packet, err := trS.readPacket()
if err != nil {
t.Fatalf("readPacket 1: %v", err)
}
if packet[0] != msgRequestSuccess {
t.Errorf("got packet %v, want packet type %d", packet, msgRequestSuccess)
}
_, err = trS.readPacket()
if err == nil {
t.Errorf("readPacket 2 succeeded")
} else if !reflect.DeepEqual(err, errMsg) {
t.Errorf("got error %#v, want %#v", err, errMsg)
}
_, err = trS.readPacket()
if err == nil {
t.Errorf("readPacket 3 succeeded")
}
}