diff options
| -rw-r--r-- | Doc/library/crypt.rst | 21 | ||||
| -rw-r--r-- | Lib/crypt.py | 84 | ||||
| -rw-r--r-- | Lib/test/test_crypt.py | 13 |
3 files changed, 60 insertions, 58 deletions
diff --git a/Doc/library/crypt.rst b/Doc/library/crypt.rst index a5556cf..5881cd0 100644 --- a/Doc/library/crypt.rst +++ b/Doc/library/crypt.rst @@ -60,6 +60,20 @@ are available on all platforms): .. versionadded:: 3.3 + +Module Attributes +----------------- + + +.. attribute:: methods + + A list of available password hashing algorithms, as + ``crypt.METHOD_*`` objects. This list is sorted from strongest to + weakest, and is guaranteed to have at least ``crypt.METHOD_CRYPT``. + +.. versionadded:: 3.3 + + Module Functions ---------------- @@ -98,13 +112,6 @@ The :mod:`crypt` module defines the following functions: Before version 3.3, *salt* must be specified as a string and cannot accept ``crypt.METHOD_*`` values (which don't exist anyway). -.. function:: methods() - - Return a list of available password hashing algorithms, as - ``crypt.METHOD_*`` objects. This list is sorted from strongest to - weakest, and is guaranteed to have at least ``crypt.METHOD_CRYPT``. - -.. versionadded:: 3.3 .. function:: mksalt(method=None) diff --git a/Lib/crypt.py b/Lib/crypt.py index dc62dba..e027d2c 100644 --- a/Lib/crypt.py +++ b/Lib/crypt.py @@ -1,61 +1,57 @@ -'''Wrapper to the POSIX crypt library call and associated functionality. -''' +"""Wrapper to the POSIX crypt library call and associated functionality.""" import _crypt +import string +from random import choice +from collections import namedtuple -saltchars = 'abcdefghijklmnopqrstuvwxyz' -saltchars += saltchars.upper() -saltchars += '0123456789./' +_saltchars = string.ascii_letters + string.digits + './' -class _MethodClass: - '''Class representing a salt method per the Modular Crypt Format or the - legacy 2-character crypt method.''' - def __init__(self, name, ident, salt_chars, total_size): - self.name = name - self.ident = ident - self.salt_chars = salt_chars - self.total_size = total_size - def __repr__(self): - return '<crypt.METHOD_%s>' % self.name +class _Method(namedtuple('_Method', 'name ident salt_chars total_size')): + """Class representing a salt method per the Modular Crypt Format or the + legacy 2-character crypt method.""" -# available salting/crypto methods -METHOD_CRYPT = _MethodClass('CRYPT', None, 2, 13) -METHOD_MD5 = _MethodClass('MD5', '1', 8, 34) -METHOD_SHA256 = _MethodClass('SHA256', '5', 16, 63) -METHOD_SHA512 = _MethodClass('SHA512', '6', 16, 106) + def __repr__(self): + return '<crypt.METHOD_{}>'.format(self.name) -def methods(): - '''Return a list of methods that are available in the platform ``crypt()`` - library, sorted from strongest to weakest. This is guaranteed to always - return at least ``[METHOD_CRYPT]``''' - method_list = [ METHOD_SHA512, METHOD_SHA256, METHOD_MD5 ] - ret = [ method for method in method_list - if len(crypt('', method)) == method.total_size ] - ret.append(METHOD_CRYPT) - return ret +def mksalt(method=None): + """Generate a salt for the specified method. -def mksalt(method = None): - '''Generate a salt for the specified method. If not specified, the - strongest available method will be used.''' - import random + If not specified, the strongest available method will be used. - if method == None: method = methods()[0] - s = '$%s$' % method.ident if method.ident else '' - s += ''.join([ random.choice(saltchars) for x in range(method.salt_chars) ]) - return(s) + """ + if method is None: + method = methods[0] + s = '${}$'.format(method.ident) if method.ident else '' + s += ''.join(choice(_saltchars) for _ in range(method.salt_chars)) + return s -def crypt(word, salt = None): - '''Return a string representing the one-way hash of a password, preturbed - by a salt. If ``salt`` is not specified or is ``None``, the strongest +def crypt(word, salt=None): + """Return a string representing the one-way hash of a password, with a salt + prepended. + + If ``salt`` is not specified or is ``None``, the strongest available method will be selected and a salt generated. Otherwise, ``salt`` may be one of the ``crypt.METHOD_*`` values, or a string as - returned by ``crypt.mksalt()``.''' - if salt == None: salt = mksalt() - elif isinstance(salt, _MethodClass): salt = mksalt(salt) - return(_crypt.crypt(word, salt)) + returned by ``crypt.mksalt()``. + + """ + if salt is None or isinstance(salt, _Method): + salt = mksalt(salt) + return _crypt.crypt(word, salt) + + +# available salting/crypto methods +METHOD_CRYPT = _Method('CRYPT', None, 2, 13) +METHOD_MD5 = _Method('MD5', '1', 8, 34) +METHOD_SHA256 = _Method('SHA256', '5', 16, 63) +METHOD_SHA512 = _Method('SHA512', '6', 16, 106) + +methods = [METHOD_SHA512, METHOD_SHA256, METHOD_MD5, METHOD_CRYPT] +methods[:-1] = [m for m in methods[:-1] if len(crypt('', m)) == m.total_size] diff --git a/Lib/test/test_crypt.py b/Lib/test/test_crypt.py index 306296f..dc107d8 100644 --- a/Lib/test/test_crypt.py +++ b/Lib/test/test_crypt.py @@ -11,24 +11,23 @@ class CryptTestCase(unittest.TestCase): print('Test encryption: ', c) def test_salt(self): - self.assertEqual(len(crypt.saltchars), 64) - for method in crypt.methods(): + self.assertEqual(len(crypt._saltchars), 64) + for method in crypt.methods: salt = crypt.mksalt(method) self.assertEqual(len(salt), method.salt_chars + (3 if method.ident else 0)) def test_saltedcrypt(self): - for method in crypt.methods(): + for method in crypt.methods: pw = crypt.crypt('assword', method) self.assertEqual(len(pw), method.total_size) pw = crypt.crypt('assword', crypt.mksalt(method)) self.assertEqual(len(pw), method.total_size) def test_methods(self): - # Gurantee that METHOD_CRYPT is the last method in crypt.methods(). - methods = crypt.methods() - self.assertTrue(len(methods) >= 1) - self.assertEqual(crypt.METHOD_CRYPT, methods[-1]) + # Gurantee that METHOD_CRYPT is the last method in crypt.methods. + self.assertTrue(len(crypt.methods) >= 1) + self.assertEqual(crypt.METHOD_CRYPT, crypt.methods[-1]) def test_main(): support.run_unittest(CryptTestCase) |