cubicweb/crypto.py
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Wed, 09 Nov 2016 16:14:17 +0100
changeset 11888 0849a5eb57b8
parent 11767 432f87a63057
child 12567 26744ad37953
child 12615 7abe23cbfda1
permissions -rw-r--r--
[rtags] Allow to 'derive' rtags Since some releases, rtags (structure underlying uicfg) have selector and may be copied using something like: new_rtags = deepcopy(original_rtags) new_rtags.__module__ = __name__ new_rtags.__select__ = custom_selector The problem is that starting from that, both rtags wil diverge and changes in original_rtags won't be considered, while we usually want to set a few specific rules only in new_rtags. To fix this problem, this cset introduces the notion of "derivated/parent" rtag, eg: new_rtags = original_rtags.derive(__name__, custom_selector) Beside easier copying, when using the above method changes in original_rtags which are not overriden by new_rtags will be considered since it only hold its specific rules but look among its parent chain for non-found keys. Along the way, flake8 unittest_rtags. Closes #16164880

# copyright 2003-2011 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.
#
# 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."""


from base64 import b64encode, b64decode

from six.moves import cPickle as pickle

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 = pickle.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 pickle.loads(string)