1 #
2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
3 # This module is free software, and you may redistribute it and/or modify
4 # under the same terms as Python, so long as this copyright message and
5 # disclaimer are retained in their original form.
6 #
7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
10 # POSSIBILITY OF SUCH DAMAGE.
11 #
12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
14 # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
17 #
18 # $Id: password.py,v 1.10 2003-11-11 00:35:13 richard Exp $
20 __doc__ = """
21 Password handling (encoding, decoding).
22 """
24 import sha, re, string, random
25 try:
26 import crypt
27 except:
28 crypt = None
29 pass
31 class PasswordValueError(ValueError):
32 ''' The password value is not valid '''
33 pass
35 def encodePassword(plaintext, scheme, other=None):
36 '''Encrypt the plaintext password.
37 '''
38 if plaintext is None:
39 plaintext = ""
40 if scheme == 'SHA':
41 s = sha.sha(plaintext).hexdigest()
42 elif scheme == 'crypt' and crypt is not None:
43 if other is not None:
44 salt = other[:2]
45 else:
46 saltchars = './0123456789'+string.letters
47 salt = random.choice(saltchars) + random.choice(saltchars)
48 s = crypt.crypt(plaintext, salt)
49 elif scheme == 'plaintext':
50 s = plaintext
51 else:
52 raise PasswordValueError, 'unknown encryption scheme %r'%scheme
53 return s
55 def generatePassword(length=8):
56 chars = string.letters+string.digits
57 return ''.join([random.choice(chars) for x in range(length)])
59 class Password:
60 '''The class encapsulates a Password property type value in the database.
62 The encoding of the password is one if None, 'SHA' or 'plaintext'. The
63 encodePassword function is used to actually encode the password from
64 plaintext. The None encoding is used in legacy databases where no
65 encoding scheme is identified.
67 The scheme is stored with the encoded data in the database:
68 {scheme}data
70 Example usage:
71 >>> p = Password('sekrit')
72 >>> p == 'sekrit'
73 1
74 >>> p != 'not sekrit'
75 1
76 >>> 'sekrit' == p
77 1
78 >>> 'not sekrit' != p
79 1
80 '''
82 default_scheme = 'SHA' # new encryptions use this scheme
83 pwre = re.compile(r'{(\w+)}(.+)')
85 def __init__(self, plaintext=None, scheme=None):
86 '''Call setPassword if plaintext is not None.'''
87 if scheme is None:
88 scheme = self.default_scheme
89 if plaintext is not None:
90 self.password = encodePassword(plaintext, self.default_scheme)
91 self.scheme = self.default_scheme
92 else:
93 self.password = None
94 self.scheme = self.default_scheme
96 def unpack(self, encrypted):
97 '''Set the password info from the scheme:<encryted info> string
98 (the inverse of __str__)
99 '''
100 m = self.pwre.match(encrypted)
101 if m:
102 self.scheme = m.group(1)
103 self.password = m.group(2)
104 else:
105 # currently plaintext - encrypt
106 self.password = encodePassword(encrypted, self.default_scheme)
107 self.scheme = self.default_scheme
109 def setPassword(self, plaintext, scheme=None):
110 '''Sets encrypts plaintext.'''
111 if scheme is None:
112 scheme = self.default_scheme
113 self.password = encodePassword(plaintext, scheme)
115 def __cmp__(self, other):
116 '''Compare this password against another password.'''
117 # check to see if we're comparing instances
118 if isinstance(other, Password):
119 if self.scheme != other.scheme:
120 return cmp(self.scheme, other.scheme)
121 return cmp(self.password, other.password)
123 # assume password is plaintext
124 if self.password is None:
125 raise ValueError, 'Password not set'
126 return cmp(self.password, encodePassword(other, self.scheme,
127 self.password))
129 def __str__(self):
130 '''Stringify the encrypted password for database storage.'''
131 if self.password is None:
132 raise ValueError, 'Password not set'
133 return '{%s}%s'%(self.scheme, self.password)
135 def test():
136 # SHA
137 p = Password('sekrit')
138 assert p == 'sekrit'
139 assert p != 'not sekrit'
140 assert 'sekrit' == p
141 assert 'not sekrit' != p
143 # crypt
144 p = Password('sekrit', 'crypt')
145 assert p == 'sekrit'
146 assert p != 'not sekrit'
147 assert 'sekrit' == p
148 assert 'not sekrit' != p
150 if __name__ == '__main__':
151 test()
153 # vim: set filetype=python ts=4 sw=4 et si