deb-python-autobahn/autobahn/twisted/util.py

131 lines
4.9 KiB
Python

###############################################################################
#
# The MIT License (MIT)
#
# Copyright (c) Crossbar.io Technologies GmbH
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
###############################################################################
from __future__ import absolute_import
import hashlib
from twisted.internet.defer import Deferred
from twisted.internet.address import IPv4Address, UNIXAddress
try:
from twisted.internet.stdio import PipeAddress
except ImportError:
# stdio.PipeAddress is only avail on Twisted 13.0+
PipeAddress = type(None)
try:
from twisted.internet.address import IPv6Address
_HAS_IPV6 = True
except ImportError:
_HAS_IPV6 = False
__all = (
'sleep',
'peer2str',
'transport_channel_id'
)
def sleep(delay, reactor=None):
"""
Inline sleep for use in co-routines (Twisted ``inlineCallback`` decorated functions).
.. seealso::
* `twisted.internet.defer.inlineCallbacks <http://twistedmatrix.com/documents/current/api/twisted.internet.defer.html#inlineCallbacks>`__
* `twisted.internet.interfaces.IReactorTime <http://twistedmatrix.com/documents/current/api/twisted.internet.interfaces.IReactorTime.html>`__
:param delay: Time to sleep in seconds.
:type delay: float
:param reactor: The Twisted reactor to use.
:type reactor: None or provider of ``IReactorTime``.
"""
if not reactor:
from twisted.internet import reactor
d = Deferred()
reactor.callLater(delay, d.callback, None)
return d
def peer2str(addr):
"""
Convert a Twisted address as returned from ``self.transport.getPeer()`` to a string.
:returns: Returns a string representation of the peer on a Twisted transport.
:rtype: unicode
"""
if isinstance(addr, IPv4Address):
res = u"tcp4:{0}:{1}".format(addr.host, addr.port)
elif _HAS_IPV6 and isinstance(addr, IPv6Address):
res = u"tcp6:{0}:{1}".format(addr.host, addr.port)
elif isinstance(addr, UNIXAddress):
res = u"unix:{0}".format(addr.name)
elif isinstance(addr, PipeAddress):
res = u"<pipe>"
else:
# gracefully fallback if we can't map the peer's address
res = u"?:{0}".format(addr)
return res
def transport_channel_id(transport, is_server, channel_id_type):
"""
Application-layer user authentication protocols are vulnerable to generic
credential forwarding attacks, where an authentication credential sent by
a client C to a server M may then be used by M to impersonate C at another
server S. To prevent such credential forwarding attacks, modern authentication
protocols rely on channel bindings. For example, WAMP-cryptosign can use
the tls-unique channel identifier provided by the TLS layer to strongly bind
authentication credentials to the underlying channel, so that a credential
received on one TLS channel cannot be forwarded on another.
"""
if channel_id_type is None:
return None
if channel_id_type not in [u'tls-unique']:
raise Exception("invalid channel ID type {}".format(channel_id_type))
if hasattr(transport, '_tlsConnection'):
# Obtain latest TLS Finished message that we expected from peer, or None if handshake is not completed.
# http://www.pyopenssl.org/en/stable/api/ssl.html#OpenSSL.SSL.Connection.get_peer_finished
if is_server:
# for routers (=servers), the channel ID is based on the TLS Finished message we
# expected to receive from the client
tls_finished_msg = transport._tlsConnection.get_peer_finished()
else:
# for clients, the channel ID is based on the TLS Finished message we sent
# to the router (=server)
tls_finished_msg = transport._tlsConnection.get_finished()
m = hashlib.sha256()
m.update(tls_finished_msg)
return m.digest()
else:
return None