| // 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" |
| crypto_rand "crypto/rand" |
| "io" |
| "io/ioutil" |
| "math/rand" |
| "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 |
| } |
| done := make(chan struct{}) |
| for { |
| ch, err := conn.Accept() |
| if err == io.EOF || err == io.ErrUnexpectedEOF { |
| 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 func() { |
| defer close(done) |
| handler(ch.(*serverChan), t) |
| }() |
| } |
| <-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("failed to request new session: %v", err) |
| } |
| defer session.Close() |
| stdin, err := session.StdinPipe() |
| if err != nil { |
| t.Fatalf("failed to obtain stdinpipe: %v", err) |
| } |
| const size = 100 * 1000 |
| for i := 0; i < 10; i++ { |
| n, err := 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) |
| } |
| } |
| |
| func TestClientCannotSendAfterEOF(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() |
| in, err := session.StdinPipe() |
| if err != nil { |
| t.Fatalf("Unable to connect channel stdin: %v", err) |
| } |
| if err := session.Shell(); err != nil { |
| t.Fatalf("Unable to execute command: %v", err) |
| } |
| if err := in.Close(); err != nil { |
| t.Fatalf("Unable to close stdin: %v", err) |
| } |
| if _, err := in.Write([]byte("foo")); err == nil { |
| t.Fatalf("Session write should fail") |
| } |
| } |
| |
| func TestClientCannotSendAfterClose(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() |
| in, err := session.StdinPipe() |
| if err != nil { |
| t.Fatalf("Unable to connect channel stdin: %v", err) |
| } |
| if err := session.Shell(); err != nil { |
| t.Fatalf("Unable to execute command: %v", err) |
| } |
| // close underlying channel |
| if err := session.channel.Close(); err != nil { |
| t.Fatalf("Unable to close session: %v", err) |
| } |
| if _, err := in.Write([]byte("foo")); err == nil { |
| t.Fatalf("Session write should fail") |
| } |
| } |
| |
| func TestClientCannotSendHugePacket(t *testing.T) { |
| // client and server use the same transport write code so this |
| // test suffices for both. |
| conn := dial(shellHandler, t) |
| defer conn.Close() |
| if err := conn.transport.writePacket(make([]byte, maxPacket*2)); err == nil { |
| t.Fatalf("huge packet write should fail") |
| } |
| } |
| |
| // windowTestBytes is the number of bytes that we'll send to the SSH server. |
| const windowTestBytes = 16000 * 200 |
| |
| // TestServerWindow writes random data to the server. The server is expected to echo |
| // the same data back, which is compared against the original. |
| func TestServerWindow(t *testing.T) { |
| origBuf := bytes.NewBuffer(make([]byte, 0, windowTestBytes)) |
| io.CopyN(origBuf, crypto_rand.Reader, windowTestBytes) |
| origBytes := origBuf.Bytes() |
| |
| conn := dial(echoHandler, t) |
| defer conn.Close() |
| session, err := conn.NewSession() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer session.Close() |
| result := make(chan []byte) |
| |
| go func() { |
| defer close(result) |
| echoedBuf := bytes.NewBuffer(make([]byte, 0, windowTestBytes)) |
| serverStdout, err := session.StdoutPipe() |
| if err != nil { |
| t.Errorf("StdoutPipe failed: %v", err) |
| return |
| } |
| n, err := copyNRandomly("stdout", echoedBuf, serverStdout, windowTestBytes) |
| if err != nil && err != io.EOF { |
| t.Errorf("Read only %d bytes from server, expected %d: %v", n, windowTestBytes, err) |
| } |
| result <- echoedBuf.Bytes() |
| }() |
| |
| serverStdin, err := session.StdinPipe() |
| if err != nil { |
| t.Fatalf("StdinPipe failed: %v", err) |
| } |
| written, err := copyNRandomly("stdin", serverStdin, origBuf, windowTestBytes) |
| if err != nil { |
| t.Fatalf("falied to copy origBuf to serverStdin: %v", err) |
| } |
| if written != windowTestBytes { |
| t.Fatalf("Wrote only %d of %d bytes to server", written, windowTestBytes) |
| } |
| |
| echoedBytes := <-result |
| |
| if !bytes.Equal(origBytes, echoedBytes) { |
| t.Fatalf("Echoed buffer differed from original, orig %d, echoed %d", len(origBytes), len(echoedBytes)) |
| } |
| } |
| |
| 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, "> ") |
| readLine(shell, t) |
| sendStatus(0, ch, t) |
| } |
| |
| func exitStatusNonZeroHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| shell := newServerShell(ch, "> ") |
| readLine(shell, t) |
| sendStatus(15, ch, t) |
| } |
| |
| func exitSignalAndStatusHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| shell := newServerShell(ch, "> ") |
| readLine(shell, t) |
| sendStatus(15, ch, t) |
| sendSignal("TERM", ch, t) |
| } |
| |
| func exitSignalHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| shell := newServerShell(ch, "> ") |
| readLine(shell, t) |
| sendSignal("TERM", ch, t) |
| } |
| |
| func exitSignalUnknownHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| shell := newServerShell(ch, "> ") |
| readLine(shell, t) |
| sendSignal("SYS", ch, t) |
| } |
| |
| func exitWithoutSignalOrStatus(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| shell := newServerShell(ch, "> ") |
| readLine(shell, t) |
| } |
| |
| func shellHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| // this string is returned to stdout |
| shell := newServerShell(ch, "golang") |
| readLine(shell, t) |
| sendStatus(0, ch, t) |
| } |
| |
| func readLine(shell *ServerTerminal, t *testing.T) { |
| if _, err := shell.ReadLine(); err != nil && err != io.EOF { |
| t.Errorf("unable to read line: %v", err) |
| } |
| } |
| |
| 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, "> ") |
| readLine(shell, t) |
| 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) |
| io.Copy(ioutil.Discard, ch) |
| } |
| |
| 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, "> ") |
| readLine(shell, t) |
| // 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") |
| } |
| } |
| |
| func echoHandler(ch *serverChan, t *testing.T) { |
| defer ch.Close() |
| if n, err := copyNRandomly("echohandler", ch, ch, windowTestBytes); err != nil { |
| t.Errorf("short write, wrote %d, expected %d: %v ", n, windowTestBytes, err) |
| } |
| } |
| |
| // copyNRandomly copies n bytes from src to dst. It uses a variable, and random, |
| // buffer size to exercise more code paths. |
| func copyNRandomly(title string, dst io.Writer, src io.Reader, n int) (int, error) { |
| var ( |
| buf = make([]byte, 32*1024) |
| written int |
| remaining = n |
| ) |
| for remaining > 0 { |
| l := rand.Intn(1 << 15) |
| if remaining < l { |
| l = remaining |
| } |
| nr, er := src.Read(buf[:l]) |
| nw, ew := dst.Write(buf[:nr]) |
| remaining -= nw |
| written += nw |
| if ew != nil { |
| return written, ew |
| } |
| if nr != nw { |
| return written, io.ErrShortWrite |
| } |
| if er != nil && er != io.EOF { |
| return written, er |
| } |
| } |
| return written, nil |
| } |
