crypto.py
author Alexandre Fayolle <alexandre.fayolle@logilab.fr>
Fri, 15 Apr 2011 15:42:17 +0200
changeset 7237 9f619715665b
parent 5424 8ecbcbff9777
child 7879 9aae456abab5
permissions -rw-r--r--
[server] improve the speed of setting relations between entities (closes #1625257) The main idea is to add methods equivalent to session.add_relation and repository.glob_add_relation which handle several relations in one call. Speed gain results from: * using cursor.executemany to run SQL statements * factorizing some code which otherwise has to be performed for each relation, such as context manager creation before calling hooks or to enable security, creation of the EditedEntity instance (when several inlined relations are set on a single entity, and consequently when refreshing the cached entity) benchmark runs 1.1x faster for non inlined entities and 125x faster for inlined entities :-)

# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
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# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
"""Simple cryptographic routines, based on python-crypto.

"""
__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)