Move all the saml stuff out to a centralised handler

synapse/handlers/saml2_handler.py

@@ -0,0 +1,86 @@
+# -*- 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 saml2
+from saml2.client import Saml2Client
+
+from synapse.api.errors import CodeMessageException
+from synapse.http.servlet import parse_string
+from synapse.rest.client.v1.login import SSOAuthHandler
+
+logger = logging.getLogger(__name__)
+
+
+class Saml2Handler:
+    def __init__(self, hs):
+        self._saml_client = Saml2Client(hs.config.saml2_sp_config)
+        self._sso_auth_handler = SSOAuthHandler(hs)
+
+    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
+        )
+
+        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)
+
+        try:
+            saml2_auth = self._saml_client.parse_authn_request_response(
+                resp_bytes, saml2.BINDING_HTTP_POST
+            )
+        except Exception as e:
+            logger.warning("Exception parsing SAML2 response", exc_info=1)
+            raise CodeMessageException(400, "Unable to parse SAML2 response: %s" % (e,))
+
+        if saml2_auth.not_signed:
+            raise CodeMessageException(400, "SAML2 response was not signed")
+
+        if "uid" not in saml2_auth.ava:
+            raise CodeMessageException(400, "uid not in SAML2 response")
+
+        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
+        )

synapse/rest/client/v1/login.py

@@ -487,19 +487,10 @@ class SAMLRedirectServlet(BaseSsoRedirectServlet):
     PATTERNS = client_patterns("/login/sso/redirect", v1=True)
 
     def __init__(self, hs):
-        self._saml_client = hs.get_saml_client()
+        self._saml_handler = hs.get_saml_handler()
 
     def get_sso_url(self, client_redirect_url):
-        reqid, info = self._saml_client.prepare_for_authenticate(
-            relay_state=client_redirect_url
-        )
-
-        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")
+        return self._saml_handler.handle_redirect_request(client_redirect_url)
 
 
 class SSOAuthHandler(object):

synapse/rest/saml2/response_resource.py

@@ -13,19 +13,11 @@
 # 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 saml2
 
 from twisted.web.resource import Resource
 from twisted.web.server import NOT_DONE_YET
 
-from synapse.api.errors import CodeMessageException
 from synapse.http.server import wrap_html_request_handler
-from synapse.http.servlet import parse_string
-from synapse.rest.client.v1.login import SSOAuthHandler
-
-logger = logging.getLogger(__name__)
 
 
 class SAML2ResponseResource(Resource):
@@ -35,8 +27,7 @@ class SAML2ResponseResource(Resource):
 
     def __init__(self, hs):
         Resource.__init__(self)
-        self._saml_client = hs.get_saml_client()
-        self._sso_auth_handler = SSOAuthHandler(hs)
+        self._saml_handler = hs.get_saml_handler()
 
     def render_POST(self, request):
         self._async_render_POST(request)
@@ -44,26 +35,4 @@ class SAML2ResponseResource(Resource):
 
     @wrap_html_request_handler
     def _async_render_POST(self, request):
-        resp_bytes = parse_string(request, "SAMLResponse", required=True)
-        relay_state = parse_string(request, "RelayState", required=True)
-
-        try:
-            saml2_auth = self._saml_client.parse_authn_request_response(
-                resp_bytes, saml2.BINDING_HTTP_POST
-            )
-        except Exception as e:
-            logger.warning("Exception parsing SAML2 response", exc_info=1)
-            raise CodeMessageException(400, "Unable to parse SAML2 response: %s" % (e,))
-
-        if saml2_auth.not_signed:
-            raise CodeMessageException(400, "SAML2 response was not signed")
-
-        if "uid" not in saml2_auth.ava:
-            raise CodeMessageException(400, "uid not in SAML2 response")
-
-        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
-        )
+        return self._saml_handler.handle_saml_response(request)

synapse/server.py

@@ -194,8 +194,8 @@ class HomeServer(object):
         "sendmail",
         "registration_handler",
         "account_validity_handler",
+        "saml2_handler",
         "event_client_serializer",
-        "saml_client",
     ]
 
     REQUIRED_ON_MASTER_STARTUP = ["user_directory_handler", "stats_handler"]
@@ -525,14 +525,14 @@ class HomeServer(object):
     def build_account_validity_handler(self):
         return AccountValidityHandler(self)
 
+    def build_saml2_handler(self):
+        from synapse.handlers.saml2_handler import Saml2Handler
+
+        return Saml2Handler(self)
+
     def build_event_client_serializer(self):
         return EventClientSerializer(self)
 
-    def build_saml_client(self):
-        from saml2.client import Saml2Client
-
-        return Saml2Client(self.config.saml2_sp_config)
-
     def remove_pusher(self, app_id, push_key, user_id):
         return self.get_pusherpool().remove_pusher(app_id, push_key, user_id)