Files
crypto/ssh/session_test.go
T
Dave Cheney 7343d5f584 go.crypto/ssh: improve channel max packet handling
This proposal moves the check for max packet into
channel.writePacket. Callers should be aware they cannot
pass a buffer larger than max packet. This is only a
concern to chanWriter.Write and appropriate guards are
already in place.

There was some max packet handling in transport.go but it was
incorrect. This has been removed.

This proposal also cleans up session_test.go.

R=gustav.paul, agl, fullung, huin
CC=golang-dev
https://golang.org/cl/6460075
2012-08-13 08:22:53 +10:00

531 lines
14 KiB
Go

// Copyright 2011 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
// Session tests.
import (
"bytes"
"io"
"io/ioutil"
"net"
"testing"
"code.google.com/p/go.crypto/ssh/terminal"
)
type serverType func(*serverChan, *testing.T)
// dial constructs a new test server and returns a *ClientConn.
func dial(handler serverType, t *testing.T) *ClientConn {
pw := password("tiger")
serverConfig.PasswordCallback = func(conn *ServerConn, user, pass string) bool {
return user == "testuser" && pass == string(pw)
}
serverConfig.PublicKeyCallback = nil
l, err := Listen("tcp", "127.0.0.1:0", serverConfig)
if err != nil {
t.Fatalf("unable to listen: %v", err)
}
go func() {
defer l.Close()
conn, err := l.Accept()
if err != nil {
t.Errorf("Unable to accept: %v", err)
return
}
defer conn.Close()
if err := conn.Handshake(); err != nil {
t.Errorf("Unable to handshake: %v", err)
return
}
for {
ch, err := conn.Accept()
if err == io.EOF {
return
}
// We sometimes get ECONNRESET rather than EOF.
if _, ok := err.(*net.OpError); ok {
return
}
if err != nil {
t.Errorf("Unable to accept incoming channel request: %v", err)
return
}
if ch.ChannelType() != "session" {
ch.Reject(UnknownChannelType, "unknown channel type")
continue
}
ch.Accept()
go handler(ch.(*serverChan), t)
}
t.Log("done")
}()
config := &ClientConfig{
User: "testuser",
Auth: []ClientAuth{
ClientAuthPassword(pw),
},
}
c, err := Dial("tcp", l.Addr().String(), config)
if err != nil {
t.Fatalf("unable to dial remote side: %v", err)
}
return c
}
// Test a simple string is returned to session.Stdout.
func TestSessionShell(t *testing.T) {
conn := dial(shellHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
stdout := new(bytes.Buffer)
session.Stdout = stdout
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %s", err)
}
if err := session.Wait(); err != nil {
t.Fatalf("Remote command did not exit cleanly: %v", err)
}
actual := stdout.String()
if actual != "golang" {
t.Fatalf("Remote shell did not return expected string: expected=golang, actual=%s", actual)
}
}
// TODO(dfc) add support for Std{in,err}Pipe when the Server supports it.
// Test a simple string is returned via StdoutPipe.
func TestSessionStdoutPipe(t *testing.T) {
conn := dial(shellHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
stdout, err := session.StdoutPipe()
if err != nil {
t.Fatalf("Unable to request StdoutPipe(): %v", err)
}
var buf bytes.Buffer
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
done := make(chan bool, 1)
go func() {
if _, err := io.Copy(&buf, stdout); err != nil {
t.Errorf("Copy of stdout failed: %v", err)
}
done <- true
}()
if err := session.Wait(); err != nil {
t.Fatalf("Remote command did not exit cleanly: %v", err)
}
<-done
actual := buf.String()
if actual != "golang" {
t.Fatalf("Remote shell did not return expected string: expected=golang, actual=%s", actual)
}
}
// Test non-0 exit status is returned correctly.
func TestExitStatusNonZero(t *testing.T) {
conn := dial(exitStatusNonZeroHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err == nil {
t.Fatalf("expected command to fail but it didn't")
}
e, ok := err.(*ExitError)
if !ok {
t.Fatalf("expected *ExitError but got %T", err)
}
if e.ExitStatus() != 15 {
t.Fatalf("expected command to exit with 15 but got %v", e.ExitStatus())
}
}
// Test 0 exit status is returned correctly.
func TestExitStatusZero(t *testing.T) {
conn := dial(exitStatusZeroHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err != nil {
t.Fatalf("expected nil but got %v", err)
}
}
// Test exit signal and status are both returned correctly.
func TestExitSignalAndStatus(t *testing.T) {
conn := dial(exitSignalAndStatusHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err == nil {
t.Fatalf("expected command to fail but it didn't")
}
e, ok := err.(*ExitError)
if !ok {
t.Fatalf("expected *ExitError but got %T", err)
}
if e.Signal() != "TERM" || e.ExitStatus() != 15 {
t.Fatalf("expected command to exit with signal TERM and status 15 but got signal %s and status %v", e.Signal(), e.ExitStatus())
}
}
// Test exit signal and status are both returned correctly.
func TestKnownExitSignalOnly(t *testing.T) {
conn := dial(exitSignalHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err == nil {
t.Fatalf("expected command to fail but it didn't")
}
e, ok := err.(*ExitError)
if !ok {
t.Fatalf("expected *ExitError but got %T", err)
}
if e.Signal() != "TERM" || e.ExitStatus() != 143 {
t.Fatalf("expected command to exit with signal TERM and status 143 but got signal %s and status %v", e.Signal(), e.ExitStatus())
}
}
// Test exit signal and status are both returned correctly.
func TestUnknownExitSignal(t *testing.T) {
conn := dial(exitSignalUnknownHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err == nil {
t.Fatalf("expected command to fail but it didn't")
}
e, ok := err.(*ExitError)
if !ok {
t.Fatalf("expected *ExitError but got %T", err)
}
if e.Signal() != "SYS" || e.ExitStatus() != 128 {
t.Fatalf("expected command to exit with signal SYS and status 128 but got signal %s and status %v", e.Signal(), e.ExitStatus())
}
}
// Test WaitMsg is not returned if the channel closes abruptly.
func TestExitWithoutStatusOrSignal(t *testing.T) {
conn := dial(exitWithoutSignalOrStatus, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err == nil {
t.Fatalf("expected command to fail but it didn't")
}
_, ok := err.(*ExitError)
if ok {
// you can't actually test for errors.errorString
// because it's not exported.
t.Fatalf("expected *errorString but got %T", err)
}
}
func TestInvalidServerMessage(t *testing.T) {
conn := dial(sendInvalidRecord, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
// Make sure that we closed all the clientChans when the connection
// failed.
session.wait()
defer session.Close()
}
// In the wild some clients (and servers) send zero sized window updates.
// Test that the client can continue after receiving a zero sized update.
func TestClientZeroWindowAdjust(t *testing.T) {
conn := dial(sendZeroWindowAdjust, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
err = session.Wait()
if err != nil {
t.Fatalf("expected nil but got %v", err)
}
}
// In the wild some clients (and servers) send zero sized window updates.
// Test that the server can continue after receiving a zero size update.
func TestServerZeroWindowAdjust(t *testing.T) {
conn := dial(exitStatusZeroHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
// send a bogus zero sized window update
session.clientChan.sendWindowAdj(0)
err = session.Wait()
if err != nil {
t.Fatalf("expected nil but got %v", err)
}
}
// Verify that the client never sends a packet larger than maxpacket.
func TestClientStdinRespectsMaxPacketSize(t *testing.T) {
conn := dial(discardHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
// try to stuff 128k of data into a 32k hole.
const size = 128 * 1024
n, err := session.clientChan.stdin.Write(make([]byte, size))
if n != size || err != nil {
t.Fatalf("failed to write: %d, %v", n, err)
}
}
// Verify that the client never accepts a packet larger than maxpacket.
func TestServerStdoutRespectsMaxPacketSize(t *testing.T) {
conn := dial(largeSendHandler, t)
defer conn.Close()
session, err := conn.NewSession()
if err != nil {
t.Fatalf("Unable to request new session: %v", err)
}
defer session.Close()
out, err := session.StdoutPipe()
if err != nil {
t.Fatalf("Unable to connect to Stdout: %v", err)
}
if err := session.Shell(); err != nil {
t.Fatalf("Unable to execute command: %v", err)
}
if _, err := ioutil.ReadAll(out); err != nil {
t.Fatalf("failed to read: %v", err)
}
}
type exitStatusMsg struct {
PeersId uint32
Request string
WantReply bool
Status uint32
}
type exitSignalMsg struct {
PeersId uint32
Request string
WantReply bool
Signal string
CoreDumped bool
Errmsg string
Lang string
}
func newServerShell(ch *serverChan, prompt string) *ServerTerminal {
term := terminal.NewTerminal(ch, prompt)
return &ServerTerminal{
Term: term,
Channel: ch,
}
}
func exitStatusZeroHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
// this string is returned to stdout
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(0, ch, t)
}
func exitStatusNonZeroHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(15, ch, t)
}
func exitSignalAndStatusHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(15, ch, t)
sendSignal("TERM", ch, t)
}
func exitSignalHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendSignal("TERM", ch, t)
}
func exitSignalUnknownHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendSignal("SYS", ch, t)
}
func exitWithoutSignalOrStatus(ch *serverChan, t *testing.T) {
defer ch.Close()
shell := newServerShell(ch, "> ")
shell.ReadLine()
}
func shellHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
// this string is returned to stdout
shell := newServerShell(ch, "golang")
shell.ReadLine()
sendStatus(0, ch, t)
}
func sendStatus(status uint32, ch *serverChan, t *testing.T) {
msg := exitStatusMsg{
PeersId: ch.remoteId,
Request: "exit-status",
WantReply: false,
Status: status,
}
if err := ch.writePacket(marshal(msgChannelRequest, msg)); err != nil {
t.Errorf("unable to send status: %v", err)
}
}
func sendSignal(signal string, ch *serverChan, t *testing.T) {
sig := exitSignalMsg{
PeersId: ch.remoteId,
Request: "exit-signal",
WantReply: false,
Signal: signal,
CoreDumped: false,
Errmsg: "Process terminated",
Lang: "en-GB-oed",
}
if err := ch.writePacket(marshal(msgChannelRequest, sig)); err != nil {
t.Errorf("unable to send signal: %v", err)
}
}
func sendInvalidRecord(ch *serverChan, t *testing.T) {
defer ch.Close()
packet := make([]byte, 1+4+4+1)
packet[0] = msgChannelData
marshalUint32(packet[1:], 29348723 /* invalid channel id */)
marshalUint32(packet[5:], 1)
packet[9] = 42
if err := ch.writePacket(packet); err != nil {
t.Errorf("unable send invalid record: %v", err)
}
}
func sendZeroWindowAdjust(ch *serverChan, t *testing.T) {
defer ch.Close()
// send a bogus zero sized window update
ch.sendWindowAdj(0)
shell := newServerShell(ch, "> ")
shell.ReadLine()
sendStatus(0, ch, t)
}
func discardHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
// grow the window to avoid being fooled by
// the initial 1 << 14 window.
ch.sendWindowAdj(1024 * 1024)
shell := newServerShell(ch, "> ")
shell.ReadLine()
io.Copy(ioutil.Discard, ch.serverConn)
}
func largeSendHandler(ch *serverChan, t *testing.T) {
defer ch.Close()
// grow the window to avoid being fooled by
// the initial 1 << 14 window.
ch.sendWindowAdj(1024 * 1024)
shell := newServerShell(ch, "> ")
shell.ReadLine()
// try to send more than the 32k window
// will allow
if err := ch.writePacket(make([]byte, 128*1024)); err == nil {
t.Errorf("wrote packet larger than 32k")
}
}