all: import golang.org/x/crypto/ssh/terminal

This merges all code from x/crypto/ssh/terminal at commit
0c6587e931a935f573efb6988c8470cd8c0a58de with no refactoring,
simply mapping util_* files to term_*.

The x/crypto history for the merge was rewritten with

    git filter-repo --path ssh/terminal/ --path-rename ssh/terminal/:

and then stitched together with "git replace --graft".

The merge preserves git blame visibility.

Updates #31044

Change-Id: Ic51fc8ec20b3a384cdd8868fde06fe69b6317695

Author: FiloSottile

term.go

@@ -4,6 +4,14 @@
 
 // Package term provides support functions for dealing with terminals, as
 // commonly found on UNIX systems.
+//
+// Putting a terminal into raw mode is the most common requirement:
+//
+// 	oldState, err := terminal.MakeRaw(0)
+// 	if err != nil {
+// 	        panic(err)
+// 	}
+// 	defer terminal.Restore(0, oldState)
 package term
 
 // IsTerminal returns whether the given file descriptor is a terminal.

term_aix.go

@@ -4,8 +4,7 @@
 
 package term
 
-import (
-	"golang.org/x/sys/unix"
-)
+import "golang.org/x/sys/unix"
 
 const ioctlReadTermios = unix.TCGETS
+const ioctlWriteTermios = unix.TCSETS

term_bsd.go

@@ -6,8 +6,7 @@
 
 package term
 
-import (
-	"golang.org/x/sys/unix"
-)
+import "golang.org/x/sys/unix"
 
 const ioctlReadTermios = unix.TIOCGETA
+const ioctlWriteTermios = unix.TIOCSETA

term_linux.go

@@ -4,8 +4,7 @@
 
 package term
 
-import (
-	"golang.org/x/sys/unix"
-)
+import "golang.org/x/sys/unix"
 
 const ioctlReadTermios = unix.TCGETS
+const ioctlWriteTermios = unix.TCSETS

term_plan9.go

@@ -5,13 +5,49 @@
 package term
 
 import (
+	"fmt"
+	"runtime"
+
 	"golang.org/x/sys/plan9"
 )
 
+type State struct{}
+
 func isTerminal(fd int) bool {
 	path, err := plan9.Fd2path(fd)
 	if err != nil {
 		return false
 	}
 	return path == "/dev/cons" || path == "/mnt/term/dev/cons"
 }
+
+// MakeRaw put the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+func MakeRaw(fd int) (*State, error) {
+	return nil, fmt.Errorf("terminal: MakeRaw not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
+}
+
+// GetState returns the current state of a terminal which may be useful to
+// restore the terminal after a signal.
+func GetState(fd int) (*State, error) {
+	return nil, fmt.Errorf("terminal: GetState not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, state *State) error {
+	return fmt.Errorf("terminal: Restore not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
+}
+
+// GetSize returns the dimensions of the given terminal.
+func GetSize(fd int) (width, height int, err error) {
+	return 0, 0, fmt.Errorf("terminal: GetSize not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
+}
+
+// ReadPassword reads a line of input from a terminal without local echo.  This
+// is commonly used for inputting passwords and other sensitive data. The slice
+// returned does not include the \n.
+func ReadPassword(fd int) ([]byte, error) {
+	return nil, fmt.Errorf("terminal: ReadPassword not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
+}

term_solaris.go

@@ -5,10 +5,118 @@
 package term
 
 import (
+	"io"
+	"syscall"
+
 	"golang.org/x/sys/unix"
 )
 
+// State contains the state of a terminal.
+type State struct {
+	termios unix.Termios
+}
+
 func isTerminal(fd int) bool {
 	_, err := unix.IoctlGetTermio(fd, unix.TCGETA)
 	return err == nil
 }
+
+// ReadPassword reads a line of input from a terminal without local echo.  This
+// is commonly used for inputting passwords and other sensitive data. The slice
+// returned does not include the \n.
+func ReadPassword(fd int) ([]byte, error) {
+	// see also: http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libast/common/uwin/getpass.c
+	val, err := unix.IoctlGetTermios(fd, unix.TCGETS)
+	if err != nil {
+		return nil, err
+	}
+	oldState := *val
+
+	newState := oldState
+	newState.Lflag &^= syscall.ECHO
+	newState.Lflag |= syscall.ICANON | syscall.ISIG
+	newState.Iflag |= syscall.ICRNL
+	err = unix.IoctlSetTermios(fd, unix.TCSETS, &newState)
+	if err != nil {
+		return nil, err
+	}
+
+	defer unix.IoctlSetTermios(fd, unix.TCSETS, &oldState)
+
+	var buf [16]byte
+	var ret []byte
+	for {
+		n, err := syscall.Read(fd, buf[:])
+		if err != nil {
+			return nil, err
+		}
+		if n == 0 {
+			if len(ret) == 0 {
+				return nil, io.EOF
+			}
+			break
+		}
+		if buf[n-1] == '\n' {
+			n--
+		}
+		ret = append(ret, buf[:n]...)
+		if n < len(buf) {
+			break
+		}
+	}
+
+	return ret, nil
+}
+
+// MakeRaw puts the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+// see http://cr.illumos.org/~webrev/andy_js/1060/
+func MakeRaw(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, unix.TCGETS)
+	if err != nil {
+		return nil, err
+	}
+
+	oldState := State{termios: *termios}
+
+	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
+	termios.Oflag &^= unix.OPOST
+	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
+	termios.Cflag &^= unix.CSIZE | unix.PARENB
+	termios.Cflag |= unix.CS8
+	termios.Cc[unix.VMIN] = 1
+	termios.Cc[unix.VTIME] = 0
+
+	if err := unix.IoctlSetTermios(fd, unix.TCSETS, termios); err != nil {
+		return nil, err
+	}
+
+	return &oldState, nil
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, oldState *State) error {
+	return unix.IoctlSetTermios(fd, unix.TCSETS, &oldState.termios)
+}
+
+// GetState returns the current state of a terminal which may be useful to
+// restore the terminal after a signal.
+func GetState(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, unix.TCGETS)
+	if err != nil {
+		return nil, err
+	}
+
+	return &State{termios: *termios}, nil
+}
+
+// GetSize returns the dimensions of the given terminal.
+func GetSize(fd int) (width, height int, err error) {
+	ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
+	if err != nil {
+		return 0, 0, err
+	}
+	return int(ws.Col), int(ws.Row), nil
+}

term_unix.go

@@ -2,15 +2,102 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build aix darwin dragonfly freebsd linux netbsd openbsd
+// +build aix darwin dragonfly freebsd linux,!appengine netbsd openbsd zos
 
 package term
 
 import (
 	"golang.org/x/sys/unix"
 )
 
+// State contains the state of a terminal.
+type State struct {
+	termios unix.Termios
+}
+
 func isTerminal(fd int) bool {
 	_, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
 	return err == nil
 }
+
+// MakeRaw put the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+func MakeRaw(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	oldState := State{termios: *termios}
+
+	// This attempts to replicate the behaviour documented for cfmakeraw in
+	// the termios(3) manpage.
+	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
+	termios.Oflag &^= unix.OPOST
+	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
+	termios.Cflag &^= unix.CSIZE | unix.PARENB
+	termios.Cflag |= unix.CS8
+	termios.Cc[unix.VMIN] = 1
+	termios.Cc[unix.VTIME] = 0
+	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, termios); err != nil {
+		return nil, err
+	}
+
+	return &oldState, nil
+}
+
+// GetState returns the current state of a terminal which may be useful to
+// restore the terminal after a signal.
+func GetState(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	return &State{termios: *termios}, nil
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, state *State) error {
+	return unix.IoctlSetTermios(fd, ioctlWriteTermios, &state.termios)
+}
+
+// GetSize returns the dimensions of the given terminal.
+func GetSize(fd int) (width, height int, err error) {
+	ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
+	if err != nil {
+		return -1, -1, err
+	}
+	return int(ws.Col), int(ws.Row), nil
+}
+
+// passwordReader is an io.Reader that reads from a specific file descriptor.
+type passwordReader int
+
+func (r passwordReader) Read(buf []byte) (int, error) {
+	return unix.Read(int(r), buf)
+}
+
+// ReadPassword reads a line of input from a terminal without local echo.  This
+// is commonly used for inputting passwords and other sensitive data. The slice
+// returned does not include the \n.
+func ReadPassword(fd int) ([]byte, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	newState := *termios
+	newState.Lflag &^= unix.ECHO
+	newState.Lflag |= unix.ICANON | unix.ISIG
+	newState.Iflag |= unix.ICRNL
+	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, &newState); err != nil {
+		return nil, err
+	}
+
+	defer unix.IoctlSetTermios(fd, ioctlWriteTermios, termios)
+
+	return readPasswordLine(passwordReader(fd))
+}