116 lines
3.4 KiB
Go
116 lines
3.4 KiB
Go
// Copyright 2011 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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// +build darwin dragonfly freebsd linux,!appengine netbsd openbsd
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// Package terminal provides support functions for dealing with terminals, as
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// commonly found on UNIX systems.
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//
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// Putting a terminal into raw mode is the most common requirement:
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//
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// oldState, err := terminal.MakeRaw(0)
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// if err != nil {
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// panic(err)
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// }
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// defer terminal.Restore(0, oldState)
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package terminal // import "golang.org/x/crypto/ssh/terminal"
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import (
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"golang.org/x/sys/unix"
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)
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// State contains the state of a terminal.
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type State struct {
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termios unix.Termios
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}
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// IsTerminal returns true if the given file descriptor is a terminal.
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func IsTerminal(fd int) bool {
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_, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
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return err == nil
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}
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// MakeRaw put the terminal connected to the given file descriptor into raw
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// mode and returns the previous state of the terminal so that it can be
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// restored.
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func MakeRaw(fd int) (*State, error) {
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termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
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if err != nil {
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return nil, err
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}
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oldState := State{termios: *termios}
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// This attempts to replicate the behaviour documented for cfmakeraw in
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// the termios(3) manpage.
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termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
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termios.Oflag &^= unix.OPOST
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termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
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termios.Cflag &^= unix.CSIZE | unix.PARENB
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termios.Cflag |= unix.CS8
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termios.Cc[unix.VMIN] = 1
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termios.Cc[unix.VTIME] = 0
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if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, termios); err != nil {
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return nil, err
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}
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return &oldState, nil
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}
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// GetState returns the current state of a terminal which may be useful to
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// restore the terminal after a signal.
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func GetState(fd int) (*State, error) {
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termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
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if err != nil {
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return nil, err
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}
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return &State{termios: *termios}, nil
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}
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// Restore restores the terminal connected to the given file descriptor to a
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// previous state.
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func Restore(fd int, state *State) error {
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return unix.IoctlSetTermios(fd, ioctlWriteTermios, &state.termios)
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}
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// GetSize returns the dimensions of the given terminal.
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func GetSize(fd int) (width, height int, err error) {
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ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
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if err != nil {
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return -1, -1, err
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}
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return int(ws.Col), int(ws.Row), nil
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}
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// passwordReader is an io.Reader that reads from a specific file descriptor.
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type passwordReader int
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func (r passwordReader) Read(buf []byte) (int, error) {
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return unix.Read(int(r), buf)
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}
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// ReadPassword reads a line of input from a terminal without local echo. This
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// is commonly used for inputting passwords and other sensitive data. The slice
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// returned does not include the \n.
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func ReadPassword(fd int) ([]byte, error) {
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termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
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if err != nil {
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return nil, err
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}
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newState := *termios
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newState.Lflag &^= unix.ECHO
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newState.Lflag |= unix.ICANON | unix.ISIG
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newState.Iflag |= unix.ICRNL
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if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, &newState); err != nil {
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return nil, err
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}
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defer func() {
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unix.IoctlSetTermios(fd, ioctlWriteTermios, termios)
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}()
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return readPasswordLine(passwordReader(fd))
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}
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