1 """Utilities to get a password and/or the current user name. 2 3 getpass(prompt[, stream]) - Prompt for a password, with echo turned off. 4 getuser() - Get the user name from the environment or password database. 5 6 GetPassWarning - This UserWarning is issued when getpass() cannot prevent 7 echoing of the password contents while reading. 8 9 On Windows, the msvcrt module will be used. 10 On the Mac EasyDialogs.AskPassword is used, if available. 11 12 """ 13 14 # Authors: Piers Lauder (original) 15 # Guido van Rossum (Windows support and cleanup) 16 # Gregory P. Smith (tty support & GetPassWarning) 17 18 import os, sys, warnings 19 20 __all__ = ["getpass","getuser","GetPassWarning"] 21 22 23 class GetPassWarning(UserWarning): pass 24 25 26 def unix_getpass(prompt='Password: ', stream=None): 27 """Prompt for a password, with echo turned off. 28 29 Args: 30 prompt: Written on stream to ask for the input. Default: 'Password: ' 31 stream: A writable file object to display the prompt. Defaults to 32 the tty. If no tty is available defaults to sys.stderr. 33 Returns: 34 The seKr3t input. 35 Raises: 36 EOFError: If our input tty or stdin was closed. 37 GetPassWarning: When we were unable to turn echo off on the input. 38 39 Always restores terminal settings before returning. 40 """ 41 fd = None 42 tty = None 43 try: 44 # Always try reading and writing directly on the tty first. 45 fd = os.open('/dev/tty', os.O_RDWR|os.O_NOCTTY) 46 tty = os.fdopen(fd, 'w+', 1) 47 input = tty 48 if not stream: 49 stream = tty 50 except EnvironmentError, e: 51 # If that fails, see if stdin can be controlled. 52 try: 53 fd = sys.stdin.fileno() 54 except (AttributeError, ValueError): 55 passwd = fallback_getpass(prompt, stream) 56 input = sys.stdin 57 if not stream: 58 stream = sys.stderr 59 60 if fd is not None: 61 passwd = None 62 try: 63 old = termios.tcgetattr(fd) # a copy to save 64 new = old[:] 65 new[3] &= ~termios.ECHO # 3 == 'lflags' 66 tcsetattr_flags = termios.TCSAFLUSH 67 if hasattr(termios, 'TCSASOFT'): 68 tcsetattr_flags |= termios.TCSASOFT 69 try: 70 termios.tcsetattr(fd, tcsetattr_flags, new) 71 passwd = _raw_input(prompt, stream, input=input) 72 finally: 73 termios.tcsetattr(fd, tcsetattr_flags, old) 74 stream.flush() # issue7208 75 except termios.error, e: 76 if passwd is not None: 77 # _raw_input succeeded. The final tcsetattr failed. Reraise 78 # instead of leaving the terminal in an unknown state. 79 raise 80 # We can't control the tty or stdin. Give up and use normal IO. 81 # fallback_getpass() raises an appropriate warning. 82 del input, tty # clean up unused file objects before blocking 83 passwd = fallback_getpass(prompt, stream) 84 85 stream.write('\n') 86 return passwd 87 88 89 def win_getpass(prompt='Password: ', stream=None): 90 """Prompt for password with echo off, using Windows getch().""" 91 if sys.stdin is not sys.__stdin__: 92 return fallback_getpass(prompt, stream) 93 import msvcrt 94 for c in prompt: 95 msvcrt.putch(c) 96 pw = "" 97 while 1: 98 c = msvcrt.getch() 99 if c == '\r' or c == '\n': 100 break 101 if c == '\003': 102 raise KeyboardInterrupt 103 if c == '\b': 104 pw = pw[:-1] 105 else: 106 pw = pw + c 107 msvcrt.putch('\r') 108 msvcrt.putch('\n') 109 return pw 110 111 112 def fallback_getpass(prompt='Password: ', stream=None): 113 warnings.warn("Can not control echo on the terminal.", GetPassWarning, 114 stacklevel=2) 115 if not stream: 116 stream = sys.stderr 117 print >>stream, "Warning: Password input may be echoed." 118 return _raw_input(prompt, stream) 119 120 121 def _raw_input(prompt="", stream=None, input=None): 122 # A raw_input() replacement that doesn't save the string in the 123 # GNU readline history. 124 if not stream: 125 stream = sys.stderr 126 if not input: 127 input = sys.stdin 128 prompt = str(prompt) 129 if prompt: 130 stream.write(prompt) 131 stream.flush() 132 # NOTE: The Python C API calls flockfile() (and unlock) during readline. 133 line = input.readline() 134 if not line: 135 raise EOFError 136 if line[-1] == '\n': 137 line = line[:-1] 138 return line 139 140 141 def getuser(): 142 """Get the username from the environment or password database. 143 144 First try various environment variables, then the password 145 database. This works on Windows as long as USERNAME is set. 146 147 """ 148 149 import os 150 151 for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'): 152 user = os.environ.get(name) 153 if user: 154 return user 155 156 # If this fails, the exception will "explain" why 157 import pwd 158 return pwd.getpwuid(os.getuid())[0] 159 160 # Bind the name getpass to the appropriate function 161 try: 162 import termios 163 # it's possible there is an incompatible termios from the 164 # McMillan Installer, make sure we have a UNIX-compatible termios 165 termios.tcgetattr, termios.tcsetattr 166 except (ImportError, AttributeError): 167 try: 168 import msvcrt 169 except ImportError: 170 try: 171 from EasyDialogs import AskPassword 172 except ImportError: 173 getpass = fallback_getpass 174 else: 175 getpass = AskPassword 176 else: 177 getpass = win_getpass 178 else: 179 getpass = unix_getpass 180
