499 lines
12 KiB
Go
499 lines
12 KiB
Go
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package ssh
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import (
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"bytes"
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"crypto/rand"
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"errors"
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"fmt"
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"io"
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"net"
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"reflect"
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"runtime"
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"strings"
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"sync"
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"testing"
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)
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type testChecker struct {
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calls []string
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}
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func (t *testChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
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if dialAddr == "bad" {
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return fmt.Errorf("dialAddr is bad")
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}
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if tcpAddr, ok := addr.(*net.TCPAddr); !ok || tcpAddr == nil {
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return fmt.Errorf("testChecker: got %T want *net.TCPAddr", addr)
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}
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t.calls = append(t.calls, fmt.Sprintf("%s %v %s %x", dialAddr, addr, key.Type(), key.Marshal()))
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return nil
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}
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// netPipe is analogous to net.Pipe, but it uses a real net.Conn, and
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// therefore is buffered (net.Pipe deadlocks if both sides start with
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// a write.)
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func netPipe() (net.Conn, net.Conn, error) {
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listener, err := net.Listen("tcp", "127.0.0.1:0")
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if err != nil {
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return nil, nil, err
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}
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defer listener.Close()
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c1, err := net.Dial("tcp", listener.Addr().String())
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if err != nil {
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return nil, nil, err
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}
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c2, err := listener.Accept()
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if err != nil {
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c1.Close()
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return nil, nil, err
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}
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return c1, c2, nil
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}
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// noiseTransport inserts ignore messages to check that the read loop
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// and the key exchange filters out these messages.
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type noiseTransport struct {
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keyingTransport
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}
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func (t *noiseTransport) writePacket(p []byte) error {
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ignore := []byte{msgIgnore}
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if err := t.keyingTransport.writePacket(ignore); err != nil {
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return err
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}
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debug := []byte{msgDebug, 1, 2, 3}
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if err := t.keyingTransport.writePacket(debug); err != nil {
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return err
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}
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return t.keyingTransport.writePacket(p)
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}
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func addNoiseTransport(t keyingTransport) keyingTransport {
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return &noiseTransport{t}
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}
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// handshakePair creates two handshakeTransports connected with each
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// other. If the noise argument is true, both transports will try to
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// confuse the other side by sending ignore and debug messages.
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func handshakePair(clientConf *ClientConfig, addr string, noise bool) (client *handshakeTransport, server *handshakeTransport, err error) {
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a, b, err := netPipe()
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if err != nil {
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return nil, nil, err
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}
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var trC, trS keyingTransport
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trC = newTransport(a, rand.Reader, true)
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trS = newTransport(b, rand.Reader, false)
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if noise {
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trC = addNoiseTransport(trC)
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trS = addNoiseTransport(trS)
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}
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clientConf.SetDefaults()
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v := []byte("version")
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client = newClientTransport(trC, v, v, clientConf, addr, a.RemoteAddr())
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serverConf := &ServerConfig{}
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serverConf.AddHostKey(testSigners["ecdsa"])
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serverConf.AddHostKey(testSigners["rsa"])
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serverConf.SetDefaults()
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server = newServerTransport(trS, v, v, serverConf)
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if err := server.waitSession(); err != nil {
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return nil, nil, fmt.Errorf("server.waitSession: %v", err)
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}
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if err := client.waitSession(); err != nil {
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return nil, nil, fmt.Errorf("client.waitSession: %v", err)
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}
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return client, server, nil
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}
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func TestHandshakeBasic(t *testing.T) {
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if runtime.GOOS == "plan9" {
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t.Skip("see golang.org/issue/7237")
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}
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checker := &syncChecker{make(chan int, 10)}
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trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr", false)
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if err != nil {
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t.Fatalf("handshakePair: %v", err)
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}
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defer trC.Close()
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defer trS.Close()
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<-checker.called
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clientDone := make(chan int, 0)
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gotHalf := make(chan int, 0)
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go func() {
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defer close(clientDone)
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// Client writes a bunch of stuff, and does a key
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// change in the middle. This should not confuse the
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// handshake in progress
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for i := 0; i < 10; i++ {
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p := []byte{msgRequestSuccess, byte(i)}
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if err := trC.writePacket(p); err != nil {
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t.Fatalf("sendPacket: %v", err)
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}
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if i == 5 {
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<-gotHalf
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// halfway through, we request a key change.
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trC.requestKeyExchange()
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// Wait until we can be sure the key
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// change has really started before we
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// write more.
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<-checker.called
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}
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}
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}()
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// Server checks that client messages come in cleanly
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i := 0
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err = nil
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for ; i < 10; i++ {
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var p []byte
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p, err = trS.readPacket()
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if err != nil {
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break
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}
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if i == 5 {
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gotHalf <- 1
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}
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want := []byte{msgRequestSuccess, byte(i)}
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if bytes.Compare(p, want) != 0 {
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t.Errorf("message %d: got %q, want %q", i, p, want)
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}
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}
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<-clientDone
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if err != nil && err != io.EOF {
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t.Fatalf("server error: %v", err)
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}
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if i != 10 {
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t.Errorf("received %d messages, want 10.", i)
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}
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close(checker.called)
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if _, ok := <-checker.called; ok {
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// If all went well, we registered exactly 2 key changes: one
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// that establishes the session, and one that we requested
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// additionally.
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t.Fatalf("got another host key checks after 2 handshakes")
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}
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}
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func TestForceFirstKex(t *testing.T) {
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// like handshakePair, but must access the keyingTransport.
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checker := &testChecker{}
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clientConf := &ClientConfig{HostKeyCallback: checker.Check}
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a, b, err := netPipe()
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if err != nil {
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t.Fatalf("netPipe: %v", err)
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}
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var trC, trS keyingTransport
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trC = newTransport(a, rand.Reader, true)
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// This is the disallowed packet:
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trC.writePacket(Marshal(&serviceRequestMsg{serviceUserAuth}))
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// Rest of the setup.
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trS = newTransport(b, rand.Reader, false)
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clientConf.SetDefaults()
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v := []byte("version")
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client := newClientTransport(trC, v, v, clientConf, "addr", a.RemoteAddr())
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serverConf := &ServerConfig{}
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serverConf.AddHostKey(testSigners["ecdsa"])
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serverConf.AddHostKey(testSigners["rsa"])
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serverConf.SetDefaults()
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server := newServerTransport(trS, v, v, serverConf)
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defer client.Close()
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defer server.Close()
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// We setup the initial key exchange, but the remote side
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// tries to send serviceRequestMsg in cleartext, which is
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// disallowed.
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if err := server.waitSession(); err == nil {
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t.Errorf("server first kex init should reject unexpected packet")
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}
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}
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func TestHandshakeAutoRekeyWrite(t *testing.T) {
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checker := &syncChecker{make(chan int, 10)}
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clientConf := &ClientConfig{HostKeyCallback: checker.Check}
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clientConf.RekeyThreshold = 500
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trC, trS, err := handshakePair(clientConf, "addr", false)
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if err != nil {
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t.Fatalf("handshakePair: %v", err)
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}
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defer trC.Close()
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defer trS.Close()
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done := make(chan int, 1)
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const numPacket = 5
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go func() {
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defer close(done)
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j := 0
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for ; j < numPacket; j++ {
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if _, err := trS.readPacket(); err != nil {
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break
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}
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}
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if j != numPacket {
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t.Errorf("got %d, want 5 messages", j)
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}
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}()
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<-checker.called
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for i := 0; i < numPacket; i++ {
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packet := make([]byte, 251)
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packet[0] = msgRequestSuccess
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if err := trC.writePacket(packet); err != nil {
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t.Errorf("writePacket: %v", err)
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}
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if i == 2 {
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// Make sure the kex is in progress.
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<-checker.called
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}
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}
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<-done
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}
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type syncChecker struct {
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called chan int
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}
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func (c *syncChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
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c.called <- 1
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return nil
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}
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func TestHandshakeAutoRekeyRead(t *testing.T) {
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sync := &syncChecker{make(chan int, 2)}
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clientConf := &ClientConfig{
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HostKeyCallback: sync.Check,
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}
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clientConf.RekeyThreshold = 500
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trC, trS, err := handshakePair(clientConf, "addr", false)
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if err != nil {
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t.Fatalf("handshakePair: %v", err)
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}
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defer trC.Close()
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defer trS.Close()
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packet := make([]byte, 501)
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packet[0] = msgRequestSuccess
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if err := trS.writePacket(packet); err != nil {
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t.Fatalf("writePacket: %v", err)
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}
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// While we read out the packet, a key change will be
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// initiated.
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done := make(chan int, 1)
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go func() {
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defer close(done)
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if _, err := trC.readPacket(); err != nil {
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t.Fatalf("readPacket(client): %v", err)
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}
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}()
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<-done
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<-sync.called
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}
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// errorKeyingTransport generates errors after a given number of
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// read/write operations.
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type errorKeyingTransport struct {
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packetConn
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readLeft, writeLeft int
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}
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func (n *errorKeyingTransport) prepareKeyChange(*algorithms, *kexResult) error {
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return nil
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}
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func (n *errorKeyingTransport) getSessionID() []byte {
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return nil
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}
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func (n *errorKeyingTransport) writePacket(packet []byte) error {
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if n.writeLeft == 0 {
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n.Close()
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return errors.New("barf")
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}
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n.writeLeft--
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return n.packetConn.writePacket(packet)
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}
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func (n *errorKeyingTransport) readPacket() ([]byte, error) {
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if n.readLeft == 0 {
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n.Close()
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return nil, errors.New("barf")
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}
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n.readLeft--
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return n.packetConn.readPacket()
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}
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func TestHandshakeErrorHandlingRead(t *testing.T) {
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for i := 0; i < 20; i++ {
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testHandshakeErrorHandlingN(t, i, -1, false)
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}
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}
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func TestHandshakeErrorHandlingWrite(t *testing.T) {
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for i := 0; i < 20; i++ {
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testHandshakeErrorHandlingN(t, -1, i, false)
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}
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}
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func TestHandshakeErrorHandlingReadCoupled(t *testing.T) {
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for i := 0; i < 20; i++ {
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testHandshakeErrorHandlingN(t, i, -1, true)
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}
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}
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func TestHandshakeErrorHandlingWriteCoupled(t *testing.T) {
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for i := 0; i < 20; i++ {
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testHandshakeErrorHandlingN(t, -1, i, true)
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}
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}
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// testHandshakeErrorHandlingN runs handshakes, injecting errors. If
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// handshakeTransport deadlocks, the go runtime will detect it and
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// panic.
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func testHandshakeErrorHandlingN(t *testing.T, readLimit, writeLimit int, coupled bool) {
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msg := Marshal(&serviceRequestMsg{strings.Repeat("x", int(minRekeyThreshold)/4)})
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a, b := memPipe()
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defer a.Close()
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defer b.Close()
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key := testSigners["ecdsa"]
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serverConf := Config{RekeyThreshold: minRekeyThreshold}
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|
|
serverConf.SetDefaults()
|
||
|
|
serverConn := newHandshakeTransport(&errorKeyingTransport{a, readLimit, writeLimit}, &serverConf, []byte{'a'}, []byte{'b'})
|
||
|
|
serverConn.hostKeys = []Signer{key}
|
||
|
|
go serverConn.readLoop()
|
||
|
|
go serverConn.kexLoop()
|
||
|
|
|
||
|
|
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()
|
||
|
|
go clientConn.kexLoop()
|
||
|
|
|
||
|
|
var wg sync.WaitGroup
|
||
|
|
|
||
|
|
for _, hs := range []packetConn{serverConn, clientConn} {
|
||
|
|
if !coupled {
|
||
|
|
wg.Add(2)
|
||
|
|
go func(c packetConn) {
|
||
|
|
for i := 0; ; i++ {
|
||
|
|
str := fmt.Sprintf("%08x", i) + strings.Repeat("x", int(minRekeyThreshold)/4-8)
|
||
|
|
err := c.writePacket(Marshal(&serviceRequestMsg{str}))
|
||
|
|
if err != nil {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
wg.Done()
|
||
|
|
c.Close()
|
||
|
|
}(hs)
|
||
|
|
go func(c packetConn) {
|
||
|
|
for {
|
||
|
|
_, err := c.readPacket()
|
||
|
|
if err != nil {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
wg.Done()
|
||
|
|
}(hs)
|
||
|
|
} else {
|
||
|
|
wg.Add(1)
|
||
|
|
go func(c packetConn) {
|
||
|
|
for {
|
||
|
|
_, err := c.readPacket()
|
||
|
|
if err != nil {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
if err := c.writePacket(msg); 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", false)
|
||
|
|
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")
|
||
|
|
}
|
||
|
|
}
|