crypto.py
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Mon, 29 Mar 2010 13:34:06 +0200
branchstable
changeset 5060 ee3b856e1406
parent 4595 bb08a75832e6
child 5421 8167de96c523
permissions -rw-r--r--
[repo] optimize massive insertion/deletion by using the new set_operation function Idea is that on massive insertion, cost of handling the list of operation become non negligeable, so we should minimize the number of operations in that list. The set_operation function ease usage of operation associated to data in session.transaction_data, and we only add the operation when data set isn't initialized yet, else we simply add data to the set. The operation then simply process accumulated data.

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

:organization: Logilab
:copyright: 2009-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""
__docformat__ = "restructuredtext en"

from pickle import dumps, loads
from base64 import b64encode, b64decode

from Crypto.Cipher import Blowfish


_CYPHERERS = {}
def _cypherer(seed):
    try:
        return _CYPHERERS[seed]
    except KeyError:
        _CYPHERERS[seed] = Blowfish.new(seed, Blowfish.MODE_ECB)
        return _CYPHERERS[seed]


def encrypt(data, seed):
    string = dumps(data)
    string = string + '*' * (8 - len(string) % 8)
    string = b64encode(_cypherer(seed).encrypt(string))
    return unicode(string)


def decrypt(string, seed):
    # pickle ignores trailing characters so we do not need to strip them off
    string = _cypherer(seed).decrypt(b64decode(string))
    return loads(string)