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author | Wim <wim@42.be> | 2017-12-03 01:24:05 +0100 |
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committer | Wim <wim@42.be> | 2017-12-03 01:24:05 +0100 |
commit | ed9118b34620f1ecd5f28506328d4ffe1b04793d (patch) | |
tree | 442998012f6779446a463e402fa7c0836edcac91 /vendor/golang.org/x/crypto/ssh/session.go | |
parent | 59e55cfbd5cc3c82236c5e8b95e5baff256f7143 (diff) | |
download | matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.tar.gz matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.tar.bz2 matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.zip |
Add sshchat dependencies in vendor
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/session.go')
-rw-r--r-- | vendor/golang.org/x/crypto/ssh/session.go | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/session.go b/vendor/golang.org/x/crypto/ssh/session.go new file mode 100644 index 00000000..d3321f6b --- /dev/null +++ b/vendor/golang.org/x/crypto/ssh/session.go @@ -0,0 +1,647 @@ +// 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 implements an interactive session described in +// "RFC 4254, section 6". + +import ( + "bytes" + "encoding/binary" + "errors" + "fmt" + "io" + "io/ioutil" + "sync" +) + +type Signal string + +// POSIX signals as listed in RFC 4254 Section 6.10. +const ( + SIGABRT Signal = "ABRT" + SIGALRM Signal = "ALRM" + SIGFPE Signal = "FPE" + SIGHUP Signal = "HUP" + SIGILL Signal = "ILL" + SIGINT Signal = "INT" + SIGKILL Signal = "KILL" + SIGPIPE Signal = "PIPE" + SIGQUIT Signal = "QUIT" + SIGSEGV Signal = "SEGV" + SIGTERM Signal = "TERM" + SIGUSR1 Signal = "USR1" + SIGUSR2 Signal = "USR2" +) + +var signals = map[Signal]int{ + SIGABRT: 6, + SIGALRM: 14, + SIGFPE: 8, + SIGHUP: 1, + SIGILL: 4, + SIGINT: 2, + SIGKILL: 9, + SIGPIPE: 13, + SIGQUIT: 3, + SIGSEGV: 11, + SIGTERM: 15, +} + +type TerminalModes map[uint8]uint32 + +// POSIX terminal mode flags as listed in RFC 4254 Section 8. +const ( + tty_OP_END = 0 + VINTR = 1 + VQUIT = 2 + VERASE = 3 + VKILL = 4 + VEOF = 5 + VEOL = 6 + VEOL2 = 7 + VSTART = 8 + VSTOP = 9 + VSUSP = 10 + VDSUSP = 11 + VREPRINT = 12 + VWERASE = 13 + VLNEXT = 14 + VFLUSH = 15 + VSWTCH = 16 + VSTATUS = 17 + VDISCARD = 18 + IGNPAR = 30 + PARMRK = 31 + INPCK = 32 + ISTRIP = 33 + INLCR = 34 + IGNCR = 35 + ICRNL = 36 + IUCLC = 37 + IXON = 38 + IXANY = 39 + IXOFF = 40 + IMAXBEL = 41 + ISIG = 50 + ICANON = 51 + XCASE = 52 + ECHO = 53 + ECHOE = 54 + ECHOK = 55 + ECHONL = 56 + NOFLSH = 57 + TOSTOP = 58 + IEXTEN = 59 + ECHOCTL = 60 + ECHOKE = 61 + PENDIN = 62 + OPOST = 70 + OLCUC = 71 + ONLCR = 72 + OCRNL = 73 + ONOCR = 74 + ONLRET = 75 + CS7 = 90 + CS8 = 91 + PARENB = 92 + PARODD = 93 + TTY_OP_ISPEED = 128 + TTY_OP_OSPEED = 129 +) + +// A Session represents a connection to a remote command or shell. +type Session struct { + // Stdin specifies the remote process's standard input. + // If Stdin is nil, the remote process reads from an empty + // bytes.Buffer. + Stdin io.Reader + + // Stdout and Stderr specify the remote process's standard + // output and error. + // + // If either is nil, Run connects the corresponding file + // descriptor to an instance of ioutil.Discard. There is a + // fixed amount of buffering that is shared for the two streams. + // If either blocks it may eventually cause the remote + // command to block. + Stdout io.Writer + Stderr io.Writer + + ch Channel // the channel backing this session + started bool // true once Start, Run or Shell is invoked. + copyFuncs []func() error + errors chan error // one send per copyFunc + + // true if pipe method is active + stdinpipe, stdoutpipe, stderrpipe bool + + // stdinPipeWriter is non-nil if StdinPipe has not been called + // and Stdin was specified by the user; it is the write end of + // a pipe connecting Session.Stdin to the stdin channel. + stdinPipeWriter io.WriteCloser + + exitStatus chan error +} + +// SendRequest sends an out-of-band channel request on the SSH channel +// underlying the session. +func (s *Session) SendRequest(name string, wantReply bool, payload []byte) (bool, error) { + return s.ch.SendRequest(name, wantReply, payload) +} + +func (s *Session) Close() error { + return s.ch.Close() +} + +// RFC 4254 Section 6.4. +type setenvRequest struct { + Name string + Value string +} + +// Setenv sets an environment variable that will be applied to any +// command executed by Shell or Run. +func (s *Session) Setenv(name, value string) error { + msg := setenvRequest{ + Name: name, + Value: value, + } + ok, err := s.ch.SendRequest("env", true, Marshal(&msg)) + if err == nil && !ok { + err = errors.New("ssh: setenv failed") + } + return err +} + +// RFC 4254 Section 6.2. +type ptyRequestMsg struct { + Term string + Columns uint32 + Rows uint32 + Width uint32 + Height uint32 + Modelist string +} + +// RequestPty requests the association of a pty with the session on the remote host. +func (s *Session) RequestPty(term string, h, w int, termmodes TerminalModes) error { + var tm []byte + for k, v := range termmodes { + kv := struct { + Key byte + Val uint32 + }{k, v} + + tm = append(tm, Marshal(&kv)...) + } + tm = append(tm, tty_OP_END) + req := ptyRequestMsg{ + Term: term, + Columns: uint32(w), + Rows: uint32(h), + Width: uint32(w * 8), + Height: uint32(h * 8), + Modelist: string(tm), + } + ok, err := s.ch.SendRequest("pty-req", true, Marshal(&req)) + if err == nil && !ok { + err = errors.New("ssh: pty-req failed") + } + return err +} + +// RFC 4254 Section 6.5. +type subsystemRequestMsg struct { + Subsystem string +} + +// RequestSubsystem requests the association of a subsystem with the session on the remote host. +// A subsystem is a predefined command that runs in the background when the ssh session is initiated +func (s *Session) RequestSubsystem(subsystem string) error { + msg := subsystemRequestMsg{ + Subsystem: subsystem, + } + ok, err := s.ch.SendRequest("subsystem", true, Marshal(&msg)) + if err == nil && !ok { + err = errors.New("ssh: subsystem request failed") + } + return err +} + +// RFC 4254 Section 6.7. +type ptyWindowChangeMsg struct { + Columns uint32 + Rows uint32 + Width uint32 + Height uint32 +} + +// WindowChange informs the remote host about a terminal window dimension change to h rows and w columns. +func (s *Session) WindowChange(h, w int) error { + req := ptyWindowChangeMsg{ + Columns: uint32(w), + Rows: uint32(h), + Width: uint32(w * 8), + Height: uint32(h * 8), + } + _, err := s.ch.SendRequest("window-change", false, Marshal(&req)) + return err +} + +// RFC 4254 Section 6.9. +type signalMsg struct { + Signal string +} + +// Signal sends the given signal to the remote process. +// sig is one of the SIG* constants. +func (s *Session) Signal(sig Signal) error { + msg := signalMsg{ + Signal: string(sig), + } + + _, err := s.ch.SendRequest("signal", false, Marshal(&msg)) + return err +} + +// RFC 4254 Section 6.5. +type execMsg struct { + Command string +} + +// Start runs cmd on the remote host. Typically, the remote +// server passes cmd to the shell for interpretation. +// A Session only accepts one call to Run, Start or Shell. +func (s *Session) Start(cmd string) error { + if s.started { + return errors.New("ssh: session already started") + } + req := execMsg{ + Command: cmd, + } + + ok, err := s.ch.SendRequest("exec", true, Marshal(&req)) + if err == nil && !ok { + err = fmt.Errorf("ssh: command %v failed", cmd) + } + if err != nil { + return err + } + return s.start() +} + +// Run runs cmd on the remote host. Typically, the remote +// server passes cmd to the shell for interpretation. +// A Session only accepts one call to Run, Start, Shell, Output, +// or CombinedOutput. +// +// The returned error is nil if the command runs, has no problems +// copying stdin, stdout, and stderr, and exits with a zero exit +// status. +// +// If the remote server does not send an exit status, an error of type +// *ExitMissingError is returned. If the command completes +// unsuccessfully or is interrupted by a signal, the error is of type +// *ExitError. Other error types may be returned for I/O problems. +func (s *Session) Run(cmd string) error { + err := s.Start(cmd) + if err != nil { + return err + } + return s.Wait() +} + +// Output runs cmd on the remote host and returns its standard output. +func (s *Session) Output(cmd string) ([]byte, error) { + if s.Stdout != nil { + return nil, errors.New("ssh: Stdout already set") + } + var b bytes.Buffer + s.Stdout = &b + err := s.Run(cmd) + return b.Bytes(), err +} + +type singleWriter struct { + b bytes.Buffer + mu sync.Mutex +} + +func (w *singleWriter) Write(p []byte) (int, error) { + w.mu.Lock() + defer w.mu.Unlock() + return w.b.Write(p) +} + +// CombinedOutput runs cmd on the remote host and returns its combined +// standard output and standard error. +func (s *Session) CombinedOutput(cmd string) ([]byte, error) { + if s.Stdout != nil { + return nil, errors.New("ssh: Stdout already set") + } + if s.Stderr != nil { + return nil, errors.New("ssh: Stderr already set") + } + var b singleWriter + s.Stdout = &b + s.Stderr = &b + err := s.Run(cmd) + return b.b.Bytes(), err +} + +// Shell starts a login shell on the remote host. A Session only +// accepts one call to Run, Start, Shell, Output, or CombinedOutput. +func (s *Session) Shell() error { + if s.started { + return errors.New("ssh: session already started") + } + + ok, err := s.ch.SendRequest("shell", true, nil) + if err == nil && !ok { + return errors.New("ssh: could not start shell") + } + if err != nil { + return err + } + return s.start() +} + +func (s *Session) start() error { + s.started = true + + type F func(*Session) + for _, setupFd := range []F{(*Session).stdin, (*Session).stdout, (*Session).stderr} { + setupFd(s) + } + + s.errors = make(chan error, len(s.copyFuncs)) + for _, fn := range s.copyFuncs { + go func(fn func() error) { + s.errors <- fn() + }(fn) + } + return nil +} + +// Wait waits for the remote command to exit. +// +// The returned error is nil if the command runs, has no problems +// copying stdin, stdout, and stderr, and exits with a zero exit +// status. +// +// If the remote server does not send an exit status, an error of type +// *ExitMissingError is returned. If the command completes +// unsuccessfully or is interrupted by a signal, the error is of type +// *ExitError. Other error types may be returned for I/O problems. +func (s *Session) Wait() error { + if !s.started { + return errors.New("ssh: session not started") + } + waitErr := <-s.exitStatus + + if s.stdinPipeWriter != nil { + s.stdinPipeWriter.Close() + } + var copyError error + for range s.copyFuncs { + if err := <-s.errors; err != nil && copyError == nil { + copyError = err + } + } + if waitErr != nil { + return waitErr + } + return copyError +} + +func (s *Session) wait(reqs <-chan *Request) error { + wm := Waitmsg{status: -1} + // Wait for msg channel to be closed before returning. + for msg := range reqs { + switch msg.Type { + case "exit-status": + wm.status = int(binary.BigEndian.Uint32(msg.Payload)) + case "exit-signal": + var sigval struct { + Signal string + CoreDumped bool + Error string + Lang string + } + if err := Unmarshal(msg.Payload, &sigval); err != nil { + return err + } + + // Must sanitize strings? + wm.signal = sigval.Signal + wm.msg = sigval.Error + wm.lang = sigval.Lang + default: + // This handles keepalives and matches + // OpenSSH's behaviour. + if msg.WantReply { + msg.Reply(false, nil) + } + } + } + if wm.status == 0 { + return nil + } + if wm.status == -1 { + // exit-status was never sent from server + if wm.signal == "" { + // signal was not sent either. RFC 4254 + // section 6.10 recommends against this + // behavior, but it is allowed, so we let + // clients handle it. + return &ExitMissingError{} + } + wm.status = 128 + if _, ok := signals[Signal(wm.signal)]; ok { + wm.status += signals[Signal(wm.signal)] + } + } + + return &ExitError{wm} +} + +// ExitMissingError is returned if a session is torn down cleanly, but +// the server sends no confirmation of the exit status. +type ExitMissingError struct{} + +func (e *ExitMissingError) Error() string { + return "wait: remote command exited without exit status or exit signal" +} + +func (s *Session) stdin() { + if s.stdinpipe { + return + } + var stdin io.Reader + if s.Stdin == nil { + stdin = new(bytes.Buffer) + } else { + r, w := io.Pipe() + go func() { + _, err := io.Copy(w, s.Stdin) + w.CloseWithError(err) + }() + stdin, s.stdinPipeWriter = r, w + } + s.copyFuncs = append(s.copyFuncs, func() error { + _, err := io.Copy(s.ch, stdin) + if err1 := s.ch.CloseWrite(); err == nil && err1 != io.EOF { + err = err1 + } + return err + }) +} + +func (s *Session) stdout() { + if s.stdoutpipe { + return + } + if s.Stdout == nil { + s.Stdout = ioutil.Discard + } + s.copyFuncs = append(s.copyFuncs, func() error { + _, err := io.Copy(s.Stdout, s.ch) + return err + }) +} + +func (s *Session) stderr() { + if s.stderrpipe { + return + } + if s.Stderr == nil { + s.Stderr = ioutil.Discard + } + s.copyFuncs = append(s.copyFuncs, func() error { + _, err := io.Copy(s.Stderr, s.ch.Stderr()) + return err + }) +} + +// sessionStdin reroutes Close to CloseWrite. +type sessionStdin struct { + io.Writer + ch Channel +} + +func (s *sessionStdin) Close() error { + return s.ch.CloseWrite() +} + +// StdinPipe returns a pipe that will be connected to the +// remote command's standard input when the command starts. +func (s *Session) StdinPipe() (io.WriteCloser, error) { + if s.Stdin != nil { + return nil, errors.New("ssh: Stdin already set") + } + if s.started { + return nil, errors.New("ssh: StdinPipe after process started") + } + s.stdinpipe = true + return &sessionStdin{s.ch, s.ch}, nil +} + +// StdoutPipe returns a pipe that will be connected to the +// remote command's standard output when the command starts. +// There is a fixed amount of buffering that is shared between +// stdout and stderr streams. If the StdoutPipe reader is +// not serviced fast enough it may eventually cause the +// remote command to block. +func (s *Session) StdoutPipe() (io.Reader, error) { + if s.Stdout != nil { + return nil, errors.New("ssh: Stdout already set") + } + if s.started { + return nil, errors.New("ssh: StdoutPipe after process started") + } + s.stdoutpipe = true + return s.ch, nil +} + +// StderrPipe returns a pipe that will be connected to the +// remote command's standard error when the command starts. +// There is a fixed amount of buffering that is shared between +// stdout and stderr streams. If the StderrPipe reader is +// not serviced fast enough it may eventually cause the +// remote command to block. +func (s *Session) StderrPipe() (io.Reader, error) { + if s.Stderr != nil { + return nil, errors.New("ssh: Stderr already set") + } + if s.started { + return nil, errors.New("ssh: StderrPipe after process started") + } + s.stderrpipe = true + return s.ch.Stderr(), nil +} + +// newSession returns a new interactive session on the remote host. +func newSession(ch Channel, reqs <-chan *Request) (*Session, error) { + s := &Session{ + ch: ch, + } + s.exitStatus = make(chan error, 1) + go func() { + s.exitStatus <- s.wait(reqs) + }() + + return s, nil +} + +// An ExitError reports unsuccessful completion of a remote command. +type ExitError struct { + Waitmsg +} + +func (e *ExitError) Error() string { + return e.Waitmsg.String() +} + +// Waitmsg stores the information about an exited remote command +// as reported by Wait. +type Waitmsg struct { + status int + signal string + msg string + lang string +} + +// ExitStatus returns the exit status of the remote command. +func (w Waitmsg) ExitStatus() int { + return w.status +} + +// Signal returns the exit signal of the remote command if +// it was terminated violently. +func (w Waitmsg) Signal() string { + return w.signal +} + +// Msg returns the exit message given by the remote command +func (w Waitmsg) Msg() string { + return w.msg +} + +// Lang returns the language tag. See RFC 3066 +func (w Waitmsg) Lang() string { + return w.lang +} + +func (w Waitmsg) String() string { + str := fmt.Sprintf("Process exited with status %v", w.status) + if w.signal != "" { + str += fmt.Sprintf(" from signal %v", w.signal) + } + if w.msg != "" { + str += fmt.Sprintf(". Reason was: %v", w.msg) + } + return str +} |