1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
# $Id$
#
# Copyright (C) 2005-2007 Gregory P. Smith (greg@krypto.org)
# Licensed to PSF under a Contributor Agreement.
#
__doc__ = """hashlib module - A common interface to many hash functions.
new(name, data=b'') - returns a new hash object implementing the
given hash function; initializing the hash
using the given binary data.
Named constructor functions are also available, these are faster
than using new(name):
md5(), sha1(), sha224(), sha256(), sha384(), and sha512()
More algorithms may be available on your platform but the above are
guaranteed to exist.
NOTE: If you want the adler32 or crc32 hash functions they are available in
the zlib module.
Choose your hash function wisely. Some have known collision weaknesses.
sha384 and sha512 will be slow on 32 bit platforms.
Hash objects have these methods:
- update(arg): Update the hash object with the bytes in arg. Repeated calls
are equivalent to a single call with the concatenation of all
the arguments.
- digest(): Return the digest of the bytes passed to the update() method
so far.
- hexdigest(): Like digest() except the digest is returned as a unicode
object of double length, containing only hexadecimal digits.
- copy(): Return a copy (clone) of the hash object. This can be used to
efficiently compute the digests of strings that share a common
initial substring.
For example, to obtain the digest of the string 'Nobody inspects the
spammish repetition':
>>> import hashlib
>>> m = hashlib.md5()
>>> m.update(b"Nobody inspects")
>>> m.update(b" the spammish repetition")
>>> m.digest()
b'\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'
More condensed:
>>> hashlib.sha224(b"Nobody inspects the spammish repetition").hexdigest()
'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'
"""
def __get_builtin_constructor(name):
if name in ('SHA1', 'sha1'):
import _sha1
return _sha1.sha1
elif name in ('MD5', 'md5'):
import _md5
return _md5.md5
elif name in ('SHA256', 'sha256', 'SHA224', 'sha224'):
import _sha256
bs = name[3:]
if bs == '256':
return _sha256.sha256
elif bs == '224':
return _sha256.sha224
elif name in ('SHA512', 'sha512', 'SHA384', 'sha384'):
import _sha512
bs = name[3:]
if bs == '512':
return _sha512.sha512
elif bs == '384':
return _sha512.sha384
raise ValueError("unsupported hash type")
def __py_new(name, data=b''):
"""new(name, data=b'') - Return a new hashing object using the named algorithm;
optionally initialized with data (which must be bytes).
"""
return __get_builtin_constructor(name)(data)
def __hash_new(name, data=b''):
"""new(name, data=b'') - Return a new hashing object using the named algorithm;
optionally initialized with data (which must be bytes).
"""
try:
return _hashlib.new(name, data)
except ValueError:
# If the _hashlib module (OpenSSL) doesn't support the named
# hash, try using our builtin implementations.
# This allows for SHA224/256 and SHA384/512 support even though
# the OpenSSL library prior to 0.9.8 doesn't provide them.
return __get_builtin_constructor(name)(data)
try:
import _hashlib
# use the wrapper of the C implementation
new = __hash_new
for opensslFuncName in filter(lambda n: n.startswith('openssl_'), dir(_hashlib)):
funcName = opensslFuncName[len('openssl_'):]
try:
# try them all, some may not work due to the OpenSSL
# version not supporting that algorithm.
f = getattr(_hashlib, opensslFuncName)
f()
# Use the C function directly (very fast)
exec(funcName + ' = f')
except ValueError:
try:
# Use the builtin implementation directly (fast)
exec(funcName + ' = __get_builtin_constructor(funcName)')
except ValueError:
# this one has no builtin implementation, don't define it
pass
# clean up our locals
del f
del opensslFuncName
del funcName
except ImportError:
# We don't have the _hashlib OpenSSL module?
# use the built in legacy interfaces via a wrapper function
new = __py_new
# lookup the C function to use directly for the named constructors
md5 = __get_builtin_constructor('md5')
sha1 = __get_builtin_constructor('sha1')
sha224 = __get_builtin_constructor('sha224')
sha256 = __get_builtin_constructor('sha256')
sha384 = __get_builtin_constructor('sha384')
sha512 = __get_builtin_constructor('sha512')
|
