1 """Simple cryptographic routines, based on python-crypto.

     2 

     3 :organization: Logilab

     4 :copyright: 2009-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

     5 :contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

     6 :license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

     7 """

     8 __docformat__ = "restructuredtext en"

     9 

    10 from pickle import dumps, loads

    11 from base64 import b64encode, b64decode

    12 

    13 from Crypto.Cipher import Blowfish

    14 

    15 

    16 _CYPHERERS = {}

    17 def _cypherer(seed):

    18     try:

    19         return _CYPHERERS[seed]

    20     except KeyError:

    21         _CYPHERERS[seed] = Blowfish.new(seed, Blowfish.MODE_ECB)

    22         return _CYPHERERS[seed]

    23 

    24 

    25 def encrypt(data, seed):

    26     string = dumps(data)

    27     string = string + '*' * (8 - len(string) % 8)

    28     string = b64encode(_cypherer(seed).encrypt(string))

    29     return unicode(string)

    30 

    31 

    32 def decrypt(string, seed):

    33     # pickle ignores trailing characters so we do not need to strip them off

    34     string = _cypherer(seed).decrypt(b64decode(string))

    35     return loads(string)