[CWEP002] refactor rql read security checking
Split 'check_read_perms' into 'check_relations_perms' which checks relations
'read' permissions and 'get_local_checks' which build dictionary of local
security checks (rql expression) for variables.
This allows to check relations 'read' permissions earlier in the process and so
to prepare insertion of the rql rewriter: we want to check permissions of the
computed relation, not permissions of relations introduced by the associated
rule, to conform to the CWEP.
Related to #3546717
# 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."""
__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)