Start implementing auth chains

synapse/handlers/_base.py

@@ -14,11 +14,15 @@
 # limitations under the License.
 
 from twisted.internet import defer
+
 from synapse.api.errors import LimitExceededError
-
 from synapse.util.async import run_on_reactor
-
 from synapse.crypto.event_signing import add_hashes_and_signatures
+from synapse.api.events.room import (
+    RoomCreateEvent, RoomMemberEvent, RoomPowerLevelsEvent, RoomJoinRulesEvent,
+)
+from synapse.api.constants import Membership, JoinRules
+from syutil.base64util import encode_base64
 
 import logging
 
@@ -55,6 +59,53 @@ class BaseHandler(object):
                 retry_after_ms=int(1000*(time_allowed - time_now)),
             )
 
+    @defer.inlineCallbacks
+    def _add_auth(self, event):
+        if event.type == RoomCreateEvent.TYPE:
+            event.auth_events = []
+            return
+
+        auth_events = []
+
+        key = (RoomPowerLevelsEvent.TYPE, "", )
+        power_level_event = event.old_state_events.get(key)
+
+        if power_level_event:
+            auth_events.append(power_level_event.event_id)
+
+        key = (RoomJoinRulesEvent.TYPE, "", )
+        join_rule_event = event.old_state_events.get(key)
+
+        key = (RoomMemberEvent.TYPE, event.user_id, )
+        member_event = event.old_state_events.get(key)
+
+        if join_rule_event:
+            join_rule = join_rule_event.content.get("join_rule")
+            is_public = join_rule == JoinRules.PUBLIC if join_rule else False
+
+            if event.type == RoomMemberEvent.TYPE:
+                if event.content["membership"] == Membership.JOIN:
+                    if is_public:
+                        auth_events.append(join_rule_event.event_id)
+                elif member_event:
+                    auth_events.append(member_event.event_id)
+
+        if member_event:
+            if member_event.content["membership"] == Membership.JOIN:
+                auth_events.append(member_event.event_id)
+
+        hashes = yield self.store.get_event_reference_hashes(
+            auth_events
+        )
+        hashes = [
+            {
+                k: encode_base64(v) for k, v in h.items()
+                if k == "sha256"
+            }
+            for h in hashes
+        ]
+        event.auth_events = zip(auth_events, hashes)
+
     @defer.inlineCallbacks
     def _on_new_room_event(self, event, snapshot, extra_destinations=[],
                            extra_users=[], suppress_auth=False):
@@ -64,6 +115,8 @@ class BaseHandler(object):
 
         yield self.state_handler.annotate_state_groups(event)
 
+        yield self._add_auth(event)
+
         logger.debug("Signing event...")
 
         add_hashes_and_signatures(
@@ -76,6 +129,8 @@ class BaseHandler(object):
             logger.debug("Authing...")
             self.auth.check(event, raises=True)
             logger.debug("Authed")
+        else:
+            logger.debug("Suppressed auth.")
 
         yield self.store.persist_event(event)