Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/getpass.py: 15%

1"""Utilities to get a password and/or the current user name. 

2 

3getpass(prompt[, stream]) - Prompt for a password, with echo turned off. 

4getuser() - Get the user name from the environment or password database. 

5 

6GetPassWarning - This UserWarning is issued when getpass() cannot prevent 

7 echoing of the password contents while reading. 

8 

9On Windows, the msvcrt module will be used. 

10 

11""" 

12 

13# Authors: Piers Lauder (original) 

14# Guido van Rossum (Windows support and cleanup) 

15# Gregory P. Smith (tty support & GetPassWarning) 

16 

17import contextlib 

18import io 

19import os 

20import sys 

21import warnings 

22 

23__all__ = ["getpass","getuser","GetPassWarning"] 

24 

25 

26class GetPassWarning(UserWarning): pass 

27 

28 

29def unix_getpass(prompt='Password: ', stream=None): 

30 """Prompt for a password, with echo turned off. 

31 

32 Args: 

33 prompt: Written on stream to ask for the input. Default: 'Password: ' 

34 stream: A writable file object to display the prompt. Defaults to 

35 the tty. If no tty is available defaults to sys.stderr. 

36 Returns: 

37 The seKr3t input. 

38 Raises: 

39 EOFError: If our input tty or stdin was closed. 

40 GetPassWarning: When we were unable to turn echo off on the input. 

41 

42 Always restores terminal settings before returning. 

43 """ 

44 passwd = None 

45 with contextlib.ExitStack() as stack: 

46 try: 

47 # Always try reading and writing directly on the tty first. 

48 fd = os.open('/dev/tty', os.O_RDWR|os.O_NOCTTY) 

49 tty = io.FileIO(fd, 'w+') 

50 stack.enter_context(tty) 

51 input = io.TextIOWrapper(tty) 

52 stack.enter_context(input) 

53 if not stream: 

54 stream = input 

55 except OSError as e: 

56 # If that fails, see if stdin can be controlled. 

57 stack.close() 

58 try: 

59 fd = sys.stdin.fileno() 

60 except (AttributeError, ValueError): 

61 fd = None 

62 passwd = fallback_getpass(prompt, stream) 

63 input = sys.stdin 

64 if not stream: 

65 stream = sys.stderr 

66 

67 if fd is not None: 

68 try: 

69 old = termios.tcgetattr(fd) # a copy to save 

70 new = old[:] 

71 new[3] &= ~termios.ECHO # 3 == 'lflags' 

72 tcsetattr_flags = termios.TCSAFLUSH 

73 if hasattr(termios, 'TCSASOFT'): 

74 tcsetattr_flags |= termios.TCSASOFT 

75 try: 

76 termios.tcsetattr(fd, tcsetattr_flags, new) 

77 passwd = _raw_input(prompt, stream, input=input) 

78 finally: 

79 termios.tcsetattr(fd, tcsetattr_flags, old) 

80 stream.flush() # issue7208 

81 except termios.error: 

82 if passwd is not None: 

83 # _raw_input succeeded. The final tcsetattr failed. Reraise 

84 # instead of leaving the terminal in an unknown state. 

85 raise 

86 # We can't control the tty or stdin. Give up and use normal IO. 

87 # fallback_getpass() raises an appropriate warning. 

88 if stream is not input: 

89 # clean up unused file objects before blocking 

90 stack.close() 

91 passwd = fallback_getpass(prompt, stream) 

92 

93 stream.write('\n') 

94 return passwd 

95 

96 

97def win_getpass(prompt='Password: ', stream=None): 

98 """Prompt for password with echo off, using Windows getch().""" 

99 if sys.stdin is not sys.__stdin__: 

100 return fallback_getpass(prompt, stream) 

101 

102 for c in prompt: 

103 msvcrt.putwch(c) 

104 pw = "" 

105 while 1: 

106 c = msvcrt.getwch() 

107 if c == '\r' or c == '\n': 

108 break 

109 if c == '\003': 

110 raise KeyboardInterrupt 

111 if c == '\b': 

112 pw = pw[:-1] 

113 else: 

114 pw = pw + c 

115 msvcrt.putwch('\r') 

116 msvcrt.putwch('\n') 

117 return pw 

118 

119 

120def fallback_getpass(prompt='Password: ', stream=None): 

121 warnings.warn("Can not control echo on the terminal.", GetPassWarning, 

122 stacklevel=2) 

123 if not stream: 

124 stream = sys.stderr 

125 print("Warning: Password input may be echoed.", file=stream) 

126 return _raw_input(prompt, stream) 

127 

128 

129def _raw_input(prompt="", stream=None, input=None): 

130 # This doesn't save the string in the GNU readline history. 

131 if not stream: 

132 stream = sys.stderr 

133 if not input: 

134 input = sys.stdin 

135 prompt = str(prompt) 

136 if prompt: 

137 try: 

138 stream.write(prompt) 

139 except UnicodeEncodeError: 

140 # Use replace error handler to get as much as possible printed. 

141 prompt = prompt.encode(stream.encoding, 'replace') 

142 prompt = prompt.decode(stream.encoding) 

143 stream.write(prompt) 

144 stream.flush() 

145 # NOTE: The Python C API calls flockfile() (and unlock) during readline. 

146 line = input.readline() 

147 if not line: 

148 raise EOFError 

149 if line[-1] == '\n': 

150 line = line[:-1] 

151 return line 

152 

153 

154def getuser(): 

155 """Get the username from the environment or password database. 

156 

157 First try various environment variables, then the password 

158 database. This works on Windows as long as USERNAME is set. 

159 

160 """ 

161 

162 for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'): 

163 user = os.environ.get(name) 

164 if user: 

165 return user 

166 

167 # If this fails, the exception will "explain" why 

168 import pwd 

169 return pwd.getpwuid(os.getuid())[0] 

170 

171# Bind the name getpass to the appropriate function 

172try: 

173 import termios 

174 # it's possible there is an incompatible termios from the 

175 # McMillan Installer, make sure we have a UNIX-compatible termios 

176 termios.tcgetattr, termios.tcsetattr 

177except (ImportError, AttributeError): 

178 try: 

179 import msvcrt 

180 except ImportError: 

181 getpass = fallback_getpass 

182 else: 

183 getpass = win_getpass 

184else: 

185 getpass = unix_getpass