Use secure hash algorithm in WebConfiguration.sign_text
Fix: PendingDeprecationWarning: HMAC() without an explicit digestmod argument is deprecated.
The default hash algorithm used by hmac.new is md5. As of today, md5 is so weak
that it's the equivalent of plaintext and can't be considered to be secured at all.
Therefor, we switch to a secure hash algorithm.
The rational for choosing sha3_512 is:
* the recommended algorithm is at least sha_256
* the stronger, the more secured and sha3_512 is the stronger available
* thinking about the future this should keep this part of the code safe long
enough before people think about checking it again
You can read more about choosing a secure hash algorithm in the NIST
recommendations https://csrc.nist.gov/Projects/Hash-Functions/NIST-Policy-on-Hash-Functions
This code modification should normally be transparent since check_text_sign is
exactly this code 'self.sign_text(text) == signature' and that sign_text is
only used in combination with it. The only impact is that the hash is going to
move from 32 char to 128 which might make html page a bit bigger and that
sha3_512 is slow to compute (which is a good thing for security)
# -*- coding: utf-8 -*-
# copyright 2012-2014 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/>.
from threading import Thread
from logging import getLogger
import zmq
from zmq.eventloop import ioloop
import zmq.eventloop.zmqstream
from cubicweb import set_log_methods
ctx = zmq.Context()
class ZMQComm(object):
"""
A simple ZMQ-based notification bus.
There should at most one instance of this class attached to a
Repository. A typical usage may be something like::
def callback(msg):
self.info('received message: %s', ' '.join(msg))
repo.app_instances_bus.subscribe('hello', callback)
to subsribe to the 'hello' kind of message. On the other side, to
emit a notification, call::
repo.app_instances_bus.publish(['hello', 'world'])
See http://docs.cubicweb.org for more details.
"""
def __init__(self):
self.ioloop = ioloop.IOLoop()
self._topics = {}
self._subscribers = []
self.publisher = None
def add_publisher(self, address):
assert self.publisher is None, "more than one publisher is not supported"
self.publisher = Publisher(self.ioloop, address)
def add_subscription(self, topic, callback):
for subscriber in self._subscribers:
subscriber.subscribe(topic, callback)
self._topics[topic] = callback
def add_subscriber(self, address):
subscriber = Subscriber(self.ioloop, address)
for topic, callback in self._topics.items():
subscriber.subscribe(topic, callback)
self._subscribers.append(subscriber)
def publish(self, msg):
if self.publisher is None:
return
self.publisher.send(msg)
def start(self):
Thread(target=self.ioloop.start).start()
def stop(self):
self.ioloop.add_callback(self.ioloop.stop)
def __del__(self):
self.ioloop.close()
class Publisher(object):
def __init__(self, ioloop, address):
self.address = address
self._topics = {}
self._subscribers = []
self.ioloop = ioloop
def callback():
s = ctx.socket(zmq.PUB)
self.stream = zmq.eventloop.zmqstream.ZMQStream(s, io_loop=ioloop)
self.stream.bind(self.address)
self.debug('start publisher on %s', self.address)
ioloop.add_callback(callback)
def send(self, msg):
self.ioloop.add_callback(lambda:self.stream.send_multipart(msg))
class Subscriber(object):
def __init__(self, ioloop, address):
self.address = address
self.dispatch_table = {}
self.ioloop = ioloop
def callback():
s = ctx.socket(zmq.SUB)
self.stream = zmq.eventloop.zmqstream.ZMQStream(s, io_loop=ioloop)
self.stream.on_recv(self.dispatch)
self.stream.connect(self.address)
self.debug('start subscriber on %s', self.address)
ioloop.add_callback(callback)
def dispatch(self, msg):
try:
f = self.dispatch_table[msg[0]]
except KeyError:
return
f(msg)
def subscribe(self, topic, callback):
self.dispatch_table[topic] = callback
self.ioloop.add_callback(lambda: self.stream.setsockopt(zmq.SUBSCRIBE, topic))
set_log_methods(Publisher, getLogger('cubicweb.zmq.pub'))
set_log_methods(Subscriber, getLogger('cubicweb.zmq.sub'))