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# -*- coding: utf-8 -*-
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import attr
import saml2
from saml2.client import Saml2Client
from synapse.api.errors import SynapseError
from synapse.http.servlet import parse_string
from synapse.rest.client.v1.login import SSOAuthHandler
logger = logging.getLogger(__name__)
class SamlHandler:
def __init__(self, hs):
self._saml_client = Saml2Client(hs.config.saml2_sp_config)
self._sso_auth_handler = SSOAuthHandler(hs)
# a map from saml session id to Saml2SessionData object
self._outstanding_requests_dict = {}
self._clock = hs.get_clock()
self._saml2_session_lifetime = hs.config.saml2_session_lifetime
def handle_redirect_request(self, client_redirect_url):
"""Handle an incoming request to /login/sso/redirect
Args:
client_redirect_url (bytes): the URL that we should redirect the
client to when everything is done
Returns:
bytes: URL to redirect to
"""
reqid, info = self._saml_client.prepare_for_authenticate(
relay_state=client_redirect_url
)
now = self._clock.time_msec()
self._outstanding_requests_dict[reqid] = Saml2SessionData(creation_time=now)
for key, value in info["headers"]:
if key == "Location":
return value
# this shouldn't happen!
raise Exception("prepare_for_authenticate didn't return a Location header")
def handle_saml_response(self, request):
"""Handle an incoming request to /_matrix/saml2/authn_response
Args:
request (SynapseRequest): the incoming request from the browser. We'll
respond to it with a redirect.
Returns:
Deferred[none]: Completes once we have handled the request.
"""
resp_bytes = parse_string(request, "SAMLResponse", required=True)
relay_state = parse_string(request, "RelayState", required=True)
# expire outstanding sessions before parse_authn_request_response checks
# the dict.
self.expire_sessions()
try:
saml2_auth = self._saml_client.parse_authn_request_response(
resp_bytes,
saml2.BINDING_HTTP_POST,
outstanding=self._outstanding_requests_dict,
)
except Exception as e:
logger.warning("Exception parsing SAML2 response: %s", e)
raise SynapseError(400, "Unable to parse SAML2 response: %s" % (e,))
if saml2_auth.not_signed:
logger.warning("SAML2 response was not signed")
raise SynapseError(400, "SAML2 response was not signed")
if "uid" not in saml2_auth.ava:
logger.warning("SAML2 response lacks a 'uid' attestation")
raise SynapseError(400, "uid not in SAML2 response")
self._outstanding_requests_dict.pop(saml2_auth.in_response_to, None)
username = saml2_auth.ava["uid"][0]
displayName = saml2_auth.ava.get("displayName", [None])[0]
return self._sso_auth_handler.on_successful_auth(
username, request, relay_state, user_display_name=displayName
)
def expire_sessions(self):
expire_before = self._clock.time_msec() - self._saml2_session_lifetime
to_expire = set()
for reqid, data in self._outstanding_requests_dict.items():
if data.creation_time < expire_before:
to_expire.add(reqid)
for reqid in to_expire:
logger.debug("Expiring session id %s", reqid)
del self._outstanding_requests_dict[reqid]
@attr.s
class Saml2SessionData:
"""Data we track about SAML2 sessions"""
# time the session was created, in milliseconds
creation_time = attr.ib()
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