Split federation OpenID userinfo endpoint out of the federation resource

This allows the OpenID userinfo endpoint to be active even if the
federation resource is not active. The OpenID userinfo endpoint
is called by integration managers to verify user actions using the
client API OpenID access token. Without this verification, the
integration manager cannot know that the access token is valid.

The OpenID userinfo endpoint will be loaded in the case that either
"federation" or "openid" resource is defined. The new "openid"
resource is defaulted to active in default configuration.

Signed-off-by: Jason Robinson <jasonr@matrix.org>

4 files changed, 93 insertions, 46 deletions

diff --git a/synapse/app/federation_reader.py b/synapse/app/federation_reader.py
index ea594f0f1a..99e8a4cf6a 100644
--- a/synapse/app/federation_reader.py
+++ b/synapse/app/federation_reader.py
@@ -87,6 +87,13 @@ class FederationReaderServer(HomeServer):
                     resources.update({
                         FEDERATION_PREFIX: TransportLayerServer(self),
                     })
+                if name == "openid" and "federation" not in res["names"]:
+                    # Only load the openid resource separately if federation resource
+                    # is not specified since federation resource includes openid
+                    # resource.
+                    resources.update({
+                        FEDERATION_PREFIX: TransportLayerServer(self, servlet_groups=["openid"]),
+                    })
 
         root_resource = create_resource_tree(resources, NoResource())
 
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 5652c6201c..0a924d7a80 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -95,6 +95,10 @@ class SynapseHomeServer(HomeServer):
         resources = {}
         for res in listener_config["resources"]:
             for name in res["names"]:
+                if name == "openid" and "federation" in res["names"]:
+                    # Skip loading openid resource if federation is defined
+                    # since federation resource will include openid
+                    continue
                 resources.update(self._configure_named_resource(
                     name, res.get("compress", False),
                 ))
@@ -192,6 +196,11 @@ class SynapseHomeServer(HomeServer):
                 FEDERATION_PREFIX: TransportLayerServer(self),
             })
 
+        if name == "openid":
+            resources.update({
+                FEDERATION_PREFIX: TransportLayerServer(self, servlet_groups=["openid"]),
+            })
+
         if name in ["static", "client"]:
             resources.update({
                 STATIC_PREFIX: File(
diff --git a/synapse/config/server.py b/synapse/config/server.py
index fb57791098..556f1efee5 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -151,7 +151,7 @@ class ServerConfig(Config):
                         "compress": gzip_responses,
                     },
                     {
-                        "names": ["federation"],
+                        "names": ["federation", "openid"],
                         "compress": False,
                     }
                 ]
@@ -170,7 +170,7 @@ class ServerConfig(Config):
                             "compress": gzip_responses,
                         },
                         {
-                            "names": ["federation"],
+                            "names": ["federation", "openid"],
                             "compress": False,
                         }
                     ]
@@ -328,7 +328,7 @@ class ServerConfig(Config):
                 # that can do automatic compression.
                 compress: true
 
-              - names: [federation]  # Federation APIs
+              - names: [federation, openid]  # Federation APIs
                 compress: false
 
             # optional list of additional endpoints which can be loaded via
@@ -350,7 +350,7 @@ class ServerConfig(Config):
             resources:
               - names: [client]
                 compress: true
-              - names: [federation]
+              - names: [federation, openid]
                 compress: false
 
           # Turn on the twisted ssh manhole service on localhost on the given
@@ -477,6 +477,7 @@ KNOWN_RESOURCES = (
     'keys',
     'media',
     'metrics',
+    'openid',
     'replication',
     'static',
     'webclient',
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 4557a9e66e..49b80beecb 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -43,9 +43,10 @@ logger = logging.getLogger(__name__)
 class TransportLayerServer(JsonResource):
     """Handles incoming federation HTTP requests"""
 
-    def __init__(self, hs):
+    def __init__(self, hs, servlet_groups=None):
         self.hs = hs
         self.clock = hs.get_clock()
+        self.servlet_groups = servlet_groups
 
         super(TransportLayerServer, self).__init__(hs, canonical_json=False)
 
@@ -67,6 +68,7 @@ class TransportLayerServer(JsonResource):
             resource=self,
             ratelimiter=self.ratelimiter,
             authenticator=self.authenticator,
+            servlet_groups=self.servlet_groups,
         )
 
 
@@ -1308,10 +1310,12 @@ FEDERATION_SERVLET_CLASSES = (
     FederationClientKeysClaimServlet,
     FederationThirdPartyInviteExchangeServlet,
     On3pidBindServlet,
-    OpenIdUserInfo,
     FederationVersionServlet,
 )
 
+OPENID_SERVLET_CLASSES = (
+    OpenIdUserInfo,
+)
 
 ROOM_LIST_CLASSES = (
     PublicRoomList,
@@ -1350,44 +1354,70 @@ GROUP_ATTESTATION_SERVLET_CLASSES = (
     FederationGroupsRenewAttestaionServlet,
 )
 
+DEFAULT_SERVLET_GROUPS = (
+    "federation",
+    "room_list",
+    "group_server",
+    "group_local",
+    "group_attestation",
+    "openid",
+)
+
 
-def register_servlets(hs, resource, authenticator, ratelimiter):
-    for servletclass in FEDERATION_SERVLET_CLASSES:
-        servletclass(
-            handler=hs.get_federation_server(),
-            authenticator=authenticator,
-            ratelimiter=ratelimiter,
-            server_name=hs.hostname,
-        ).register(resource)
-
-    for servletclass in ROOM_LIST_CLASSES:
-        servletclass(
-            handler=hs.get_room_list_handler(),
-            authenticator=authenticator,
-            ratelimiter=ratelimiter,
-            server_name=hs.hostname,
-        ).register(resource)
-
-    for servletclass in GROUP_SERVER_SERVLET_CLASSES:
-        servletclass(
-            handler=hs.get_groups_server_handler(),
-            authenticator=authenticator,
-            ratelimiter=ratelimiter,
-            server_name=hs.hostname,
-        ).register(resource)
-
-    for servletclass in GROUP_LOCAL_SERVLET_CLASSES:
-        servletclass(
-            handler=hs.get_groups_local_handler(),
-            authenticator=authenticator,
-            ratelimiter=ratelimiter,
-            server_name=hs.hostname,
-        ).register(resource)
-
-    for servletclass in GROUP_ATTESTATION_SERVLET_CLASSES:
-        servletclass(
-            handler=hs.get_groups_attestation_renewer(),
-            authenticator=authenticator,
-            ratelimiter=ratelimiter,
-            server_name=hs.hostname,
-        ).register(resource)
+def register_servlets(hs, resource, authenticator, ratelimiter, servlet_groups=None):
+    if not servlet_groups:
+        servlet_groups = DEFAULT_SERVLET_GROUPS
+
+    if "federation" in servlet_groups:
+        for servletclass in FEDERATION_SERVLET_CLASSES:
+            servletclass(
+                handler=hs.get_federation_server(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)
+
+    if "openid" in servlet_groups:
+        for servletclass in OPENID_SERVLET_CLASSES:
+            servletclass(
+                handler=hs.get_federation_server(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)
+
+    if "room_list" in servlet_groups:
+        for servletclass in ROOM_LIST_CLASSES:
+            servletclass(
+                handler=hs.get_room_list_handler(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)
+
+    if "group_server" in servlet_groups:
+        for servletclass in GROUP_SERVER_SERVLET_CLASSES:
+            servletclass(
+                handler=hs.get_groups_server_handler(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)
+
+    if "group_local" in servlet_groups:
+        for servletclass in GROUP_LOCAL_SERVLET_CLASSES:
+            servletclass(
+                handler=hs.get_groups_local_handler(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)
+
+    if "group_attestation" in servlet_groups:
+        for servletclass in GROUP_ATTESTATION_SERVLET_CLASSES:
+            servletclass(
+                handler=hs.get_groups_attestation_renewer(),
+                authenticator=authenticator,
+                ratelimiter=ratelimiter,
+                server_name=hs.hostname,
+            ).register(resource)