diff options
Diffstat (limited to 'Lib/getpass.py')
| -rw-r--r-- | Lib/getpass.py | 69 |
1 files changed, 62 insertions, 7 deletions
diff --git a/Lib/getpass.py b/Lib/getpass.py index bd0097ced94..1dd40e25e09 100644 --- a/Lib/getpass.py +++ b/Lib/getpass.py @@ -1,6 +1,7 @@ """Utilities to get a password and/or the current user name. -getpass(prompt[, stream]) - Prompt for a password, with echo turned off. +getpass(prompt[, stream[, echo_char]]) - Prompt for a password, with echo +turned off and optional keyboard feedback. getuser() - Get the user name from the environment or password database. GetPassWarning - This UserWarning is issued when getpass() cannot prevent @@ -25,13 +26,15 @@ __all__ = ["getpass","getuser","GetPassWarning"] class GetPassWarning(UserWarning): pass -def unix_getpass(prompt='Password: ', stream=None): +def unix_getpass(prompt='Password: ', stream=None, *, echo_char=None): """Prompt for a password, with echo turned off. Args: prompt: Written on stream to ask for the input. Default: 'Password: ' stream: A writable file object to display the prompt. Defaults to the tty. If no tty is available defaults to sys.stderr. + echo_char: A string used to mask input (e.g., '*'). If None, input is + hidden. Returns: The seKr3t input. Raises: @@ -40,6 +43,8 @@ def unix_getpass(prompt='Password: ', stream=None): Always restores terminal settings before returning. """ + _check_echo_char(echo_char) + passwd = None with contextlib.ExitStack() as stack: try: @@ -68,12 +73,16 @@ def unix_getpass(prompt='Password: ', stream=None): old = termios.tcgetattr(fd) # a copy to save new = old[:] new[3] &= ~termios.ECHO # 3 == 'lflags' + if echo_char: + new[3] &= ~termios.ICANON tcsetattr_flags = termios.TCSAFLUSH if hasattr(termios, 'TCSASOFT'): tcsetattr_flags |= termios.TCSASOFT try: termios.tcsetattr(fd, tcsetattr_flags, new) - passwd = _raw_input(prompt, stream, input=input) + passwd = _raw_input(prompt, stream, input=input, + echo_char=echo_char) + finally: termios.tcsetattr(fd, tcsetattr_flags, old) stream.flush() # issue7208 @@ -93,10 +102,11 @@ def unix_getpass(prompt='Password: ', stream=None): return passwd -def win_getpass(prompt='Password: ', stream=None): +def win_getpass(prompt='Password: ', stream=None, *, echo_char=None): """Prompt for password with echo off, using Windows getwch().""" if sys.stdin is not sys.__stdin__: return fallback_getpass(prompt, stream) + _check_echo_char(echo_char) for c in prompt: msvcrt.putwch(c) @@ -108,25 +118,39 @@ def win_getpass(prompt='Password: ', stream=None): if c == '\003': raise KeyboardInterrupt if c == '\b': + if echo_char and pw: + msvcrt.putwch('\b') + msvcrt.putwch(' ') + msvcrt.putwch('\b') pw = pw[:-1] else: pw = pw + c + if echo_char: + msvcrt.putwch(echo_char) msvcrt.putwch('\r') msvcrt.putwch('\n') return pw -def fallback_getpass(prompt='Password: ', stream=None): +def fallback_getpass(prompt='Password: ', stream=None, *, echo_char=None): + _check_echo_char(echo_char) import warnings warnings.warn("Can not control echo on the terminal.", GetPassWarning, stacklevel=2) if not stream: stream = sys.stderr print("Warning: Password input may be echoed.", file=stream) - return _raw_input(prompt, stream) + return _raw_input(prompt, stream, echo_char=echo_char) + +def _check_echo_char(echo_char): + # ASCII excluding control characters + if echo_char and not (echo_char.isprintable() and echo_char.isascii()): + raise ValueError("'echo_char' must be a printable ASCII string, " + f"got: {echo_char!r}") -def _raw_input(prompt="", stream=None, input=None): + +def _raw_input(prompt="", stream=None, input=None, echo_char=None): # This doesn't save the string in the GNU readline history. if not stream: stream = sys.stderr @@ -143,6 +167,8 @@ def _raw_input(prompt="", stream=None, input=None): stream.write(prompt) stream.flush() # NOTE: The Python C API calls flockfile() (and unlock) during readline. + if echo_char: + return _readline_with_echo_char(stream, input, echo_char) line = input.readline() if not line: raise EOFError @@ -151,6 +177,35 @@ def _raw_input(prompt="", stream=None, input=None): return line +def _readline_with_echo_char(stream, input, echo_char): + passwd = "" + eof_pressed = False + while True: + char = input.read(1) + if char == '\n' or char == '\r': + break + elif char == '\x03': + raise KeyboardInterrupt + elif char == '\x7f' or char == '\b': + if passwd: + stream.write("\b \b") + stream.flush() + passwd = passwd[:-1] + elif char == '\x04': + if eof_pressed: + break + else: + eof_pressed = True + elif char == '\x00': + continue + else: + passwd += char + stream.write(echo_char) + stream.flush() + eof_pressed = False + return passwd + + def getuser(): """Get the username from the environment or password database. |