Add an openidish mechanism for proving to third parties that you own a given user_id

synapse/rest/client/v2_alpha/openid.py

@@ -0,0 +1,96 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015, 2016 OpenMarket Ltd
+#
+# 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.
+
+
+from ._base import client_v2_patterns
+
+from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from synapse.api.errors import AuthError
+from synapse.util.stringutils import random_string
+
+from twisted.internet import defer
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class IdTokenServlet(RestServlet):
+    """
+    Get a bearer token that may be passed to a third party to confirm ownership
+    of a matrix user id.
+
+    The format of the response could be made compatible with the format given
+    in http://openid.net/specs/openid-connect-core-1_0.html#TokenResponse
+
+    But instead of returning a signed "id_token" the response contains the
+    name of the issuing matrix homeserver. This means that for now the third
+    party will need to check the validity of the "id_token" against the
+    federation /openid/userinfo endpoint of the homeserver.
+
+    Request:
+
+    POST /user/{user_id}/openid/token?access_token=... HTTP/1.1
+
+    {}
+
+    Response:
+
+    HTTP/1.1 200 OK
+    {
+        "access_token": "ABDEFGH",
+        "token_type": "Bearer",
+        "matrix_server_name": "example.com",
+        "expires_in": 3600,
+    }
+    """
+    PATTERNS = client_v2_patterns(
+        "/user/(?P<user_id>[^/]*)/openid/token"
+    )
+
+    EXPIRES_MS = 3600 * 1000
+
+    def __init__(self, hs):
+        super(IdTokenServlet, self).__init__()
+        self.auth = hs.get_auth()
+        self.store = hs.get_datastore()
+        self.clock = hs.get_clock()
+        self.server_name = hs.config.server_name
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, user_id):
+        requester = yield self.auth.get_user_by_req(request)
+        if user_id != requester.user.to_string():
+            raise AuthError(403, "Cannot request tokens for other users.")
+
+        # Parse the request body to make sure it's JSON, but ignore the contents
+        # for now.
+        parse_json_object_from_request(request)
+
+        token = random_string(24)
+        ts_valid_until_ms = self.clock.time_msec() + self.EXPIRES_MS
+
+        yield self.store.insert_open_id_token(token, ts_valid_until_ms, user_id)
+
+        defer.returnValue((200, {
+            "access_token": token,
+            "token_type": "Bearer",
+            "matrix_server_name": self.server_name,
+            "expires_in": self.EXPIRES_MS / 1000,
+        }))
+
+
+def register_servlets(hs, http_server):
+    IdTokenServlet(hs).register(http_server)