static-file: properly set/use cache header for static file (closes #2255013)
This changesets enables the standard http cache mechanism where the static
controller may reply "304 Not modified" based on `last-modified` in HTTP
response and `if-modified-since` in HTTP query. The last modified time is
computed using the file-system information.
The pre-existing logic using an `Expires` header to prevent client from sending
request stay in place. The new logic just prevents sending the file again if not
necessary.
# 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)