diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 39fd9954d5..a31f037748 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -217,6 +217,9 @@ class EventContentFields:
# For "marker" events
MSC2716_MARKER_INSERTION = "org.matrix.msc2716.marker.insertion"
+ # The authorising user for joining a restricted room.
+ AUTHORISING_USER = "join_authorised_via_users_server"
+
class RoomTypes:
"""Understood values of the room_type field of m.room.create events."""
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index eef354de6e..7a1adc2750 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -102,11 +102,11 @@ def validate_event_for_room_version(
room_version_obj.msc3083_join_rules
and event.type == EventTypes.Member
and event.membership == Membership.JOIN
- and "join_authorised_via_users_server" in event.content
+ and EventContentFields.AUTHORISING_USER in event.content
)
if is_invite_via_allow_rule:
authoriser_domain = get_domain_from_id(
- event.content["join_authorised_via_users_server"]
+ event.content[EventContentFields.AUTHORISING_USER]
)
if not event.signatures.get(authoriser_domain):
raise AuthError(403, "Event not signed by authorising server")
@@ -413,7 +413,9 @@ def _is_membership_change_allowed(
# Note that if the caller is in the room or invited, then they do
# not need to meet the allow rules.
if not caller_in_room and not caller_invited:
- authorising_user = event.content.get("join_authorised_via_users_server")
+ authorising_user = event.content.get(
+ EventContentFields.AUTHORISING_USER
+ )
if authorising_user is None:
raise AuthError(403, "Join event is missing authorising user.")
@@ -868,10 +870,10 @@ def auth_types_for_event(
auth_types.add(key)
if room_version.msc3083_join_rules and membership == Membership.JOIN:
- if "join_authorised_via_users_server" in event.content:
+ if EventContentFields.AUTHORISING_USER in event.content:
key = (
EventTypes.Member,
- event.content["join_authorised_via_users_server"],
+ event.content[EventContentFields.AUTHORISING_USER],
)
auth_types.add(key)
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index a13fb0148f..520edbbf61 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -105,7 +105,7 @@ def prune_event_dict(room_version: RoomVersion, event_dict: dict) -> dict:
if event_type == EventTypes.Member:
add_fields("membership")
if room_version.msc3375_redaction_rules:
- add_fields("join_authorised_via_users_server")
+ add_fields(EventContentFields.AUTHORISING_USER)
elif event_type == EventTypes.Create:
# MSC2176 rules state that create events cannot be redacted.
if room_version.msc2176_redaction_rules:
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 024e440ff4..0cd424e12a 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -15,7 +15,7 @@
import logging
from collections import namedtuple
-from synapse.api.constants import MAX_DEPTH, EventTypes, Membership
+from synapse.api.constants import MAX_DEPTH, EventContentFields, EventTypes, Membership
from synapse.api.errors import Codes, SynapseError
from synapse.api.room_versions import EventFormatVersions, RoomVersion
from synapse.crypto.event_signing import check_event_content_hash
@@ -184,10 +184,10 @@ async def _check_sigs_on_pdu(
room_version.msc3083_join_rules
and pdu.type == EventTypes.Member
and pdu.membership == Membership.JOIN
- and "join_authorised_via_users_server" in pdu.content
+ and EventContentFields.AUTHORISING_USER in pdu.content
):
authorising_server = get_domain_from_id(
- pdu.content["join_authorised_via_users_server"]
+ pdu.content[EventContentFields.AUTHORISING_USER]
)
try:
await keyring.verify_event_for_server(
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index 584836c04a..2ab4dec88f 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -37,7 +37,7 @@ from typing import (
import attr
from prometheus_client import Counter
-from synapse.api.constants import EventTypes, Membership
+from synapse.api.constants import EventContentFields, EventTypes, Membership
from synapse.api.errors import (
CodeMessageException,
Codes,
@@ -875,9 +875,9 @@ class FederationClient(FederationBase):
# If the join is being authorised via allow rules, we need to send
# the /send_join back to the same server that was originally used
# with /make_join.
- if "join_authorised_via_users_server" in pdu.content:
+ if EventContentFields.AUTHORISING_USER in pdu.content:
destinations = [
- get_domain_from_id(pdu.content["join_authorised_via_users_server"])
+ get_domain_from_id(pdu.content[EventContentFields.AUTHORISING_USER])
]
return await self._try_destination_list(
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 83f11d6b88..d8c0b86f23 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -34,7 +34,7 @@ from twisted.internet import defer
from twisted.internet.abstract import isIPAddress
from twisted.python import failure
-from synapse.api.constants import EduTypes, EventTypes, Membership
+from synapse.api.constants import EduTypes, EventContentFields, EventTypes, Membership
from synapse.api.errors import (
AuthError,
Codes,
@@ -765,11 +765,11 @@ class FederationServer(FederationBase):
if (
room_version.msc3083_join_rules
and event.membership == Membership.JOIN
- and "join_authorised_via_users_server" in event.content
+ and EventContentFields.AUTHORISING_USER in event.content
):
# We can only authorise our own users.
authorising_server = get_domain_from_id(
- event.content["join_authorised_via_users_server"]
+ event.content[EventContentFields.AUTHORISING_USER]
)
if authorising_server != self.server_name:
raise SynapseError(
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 0a10a5c28a..043ca4a224 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -27,7 +27,12 @@ from unpaddedbase64 import decode_base64
from twisted.internet import defer
from synapse import event_auth
-from synapse.api.constants import EventTypes, Membership, RejectedReason
+from synapse.api.constants import (
+ EventContentFields,
+ EventTypes,
+ Membership,
+ RejectedReason,
+)
from synapse.api.errors import (
AuthError,
CodeMessageException,
@@ -716,7 +721,7 @@ class FederationHandler(BaseHandler):
if include_auth_user_id:
event_content[
- "join_authorised_via_users_server"
+ EventContentFields.AUTHORISING_USER
] = await self._event_auth_handler.get_user_which_could_invite(
room_id,
state_ids,
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 02103f6c9a..29b3e41cc9 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -573,6 +573,14 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
errcode=Codes.BAD_JSON,
)
+ # The event content should *not* include the authorising user as
+ # it won't be properly signed. Strip it out since it might come
+ # back from a client updating a display name / avatar.
+ #
+ # This only applies to restricted rooms, but there should be no reason
+ # for a client to include it. Unconditionally remove it.
+ content.pop(EventContentFields.AUTHORISING_USER, None)
+
effective_membership_state = action
if action in ["kick", "unban"]:
effective_membership_state = "leave"
@@ -939,7 +947,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
# be included in the event content in order to efficiently validate
# the event.
content[
- "join_authorised_via_users_server"
+ EventContentFields.AUTHORISING_USER
] = await self.event_auth_handler.get_user_which_could_invite(
room_id,
current_state_ids,
|
