mirror of
https://github.com/python/cpython.git
synced 2024-12-01 11:15:56 +01:00
62 lines
1.8 KiB
Python
62 lines
1.8 KiB
Python
"""Wrapper to the POSIX crypt library call and associated functionality."""
|
|
|
|
import _crypt
|
|
import string as _string
|
|
from random import SystemRandom as _SystemRandom
|
|
from collections import namedtuple as _namedtuple
|
|
|
|
|
|
_saltchars = _string.ascii_letters + _string.digits + './'
|
|
_sr = _SystemRandom()
|
|
|
|
|
|
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."""
|
|
|
|
def __repr__(self):
|
|
return '<crypt.METHOD_{}>'.format(self.name)
|
|
|
|
|
|
def mksalt(method=None):
|
|
"""Generate a salt for the specified method.
|
|
|
|
If not specified, the strongest available method will be used.
|
|
|
|
"""
|
|
if method is None:
|
|
method = methods[0]
|
|
s = '${}$'.format(method.ident) if method.ident else ''
|
|
s += ''.join(_sr.choice(_saltchars) for char in range(method.salt_chars))
|
|
return s
|
|
|
|
|
|
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 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 = []
|
|
for _method in (METHOD_SHA512, METHOD_SHA256, METHOD_MD5, METHOD_CRYPT):
|
|
_result = crypt('', _method)
|
|
if _result and len(_result) == _method.total_size:
|
|
methods.append(_method)
|
|
del _result, _method
|