Enforce MSC2209: auth rules for notifications in power level event (#7502)

In a new room version, the "notifications" key of power level events are
subject to restricted auth rules.
This commit is contained in:
Patrick Cloke 2020-05-14 12:38:17 -04:00 committed by GitHub
parent 5611644519
commit fef3ff5cc4
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4 changed files with 65 additions and 3 deletions

1
changelog.d/7502.feature Normal file
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@ -0,0 +1 @@
Add additional authentication checks for m.room.power_levels event per [MSC2209](https://github.com/matrix-org/matrix-doc/pull/2209).

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@ -58,7 +58,11 @@ class RoomVersion(object):
enforce_key_validity = attr.ib() # bool
# bool: before MSC2261/MSC2432, m.room.aliases had special auth rules and redaction rules
special_case_aliases_auth = attr.ib(type=bool, default=False)
special_case_aliases_auth = attr.ib(type=bool)
# bool: MSC2209: Check 'notifications' key while verifying
# m.room.power_levels auth rules.
limit_notifications_power_levels = attr.ib(type=bool)
class RoomVersions(object):
@ -69,6 +73,7 @@ class RoomVersions(object):
StateResolutionVersions.V1,
enforce_key_validity=False,
special_case_aliases_auth=True,
limit_notifications_power_levels=False,
)
V2 = RoomVersion(
"2",
@ -77,6 +82,7 @@ class RoomVersions(object):
StateResolutionVersions.V2,
enforce_key_validity=False,
special_case_aliases_auth=True,
limit_notifications_power_levels=False,
)
V3 = RoomVersion(
"3",
@ -85,6 +91,7 @@ class RoomVersions(object):
StateResolutionVersions.V2,
enforce_key_validity=False,
special_case_aliases_auth=True,
limit_notifications_power_levels=False,
)
V4 = RoomVersion(
"4",
@ -93,6 +100,7 @@ class RoomVersions(object):
StateResolutionVersions.V2,
enforce_key_validity=False,
special_case_aliases_auth=True,
limit_notifications_power_levels=False,
)
V5 = RoomVersion(
"5",
@ -101,6 +109,7 @@ class RoomVersions(object):
StateResolutionVersions.V2,
enforce_key_validity=True,
special_case_aliases_auth=True,
limit_notifications_power_levels=False,
)
MSC2432_DEV = RoomVersion(
"org.matrix.msc2432",
@ -109,6 +118,16 @@ class RoomVersions(object):
StateResolutionVersions.V2,
enforce_key_validity=True,
special_case_aliases_auth=False,
limit_notifications_power_levels=False,
)
MSC2209_DEV = RoomVersion(
"org.matrix.msc2209",
RoomDisposition.UNSTABLE,
EventFormatVersions.V3,
StateResolutionVersions.V2,
enforce_key_validity=True,
special_case_aliases_auth=True,
limit_notifications_power_levels=True,
)
@ -121,5 +140,6 @@ KNOWN_ROOM_VERSIONS = {
RoomVersions.V4,
RoomVersions.V5,
RoomVersions.MSC2432_DEV,
RoomVersions.MSC2209_DEV,
)
} # type: Dict[str, RoomVersion]

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@ -181,7 +181,7 @@ def check(
_can_send_event(event, auth_events)
if event.type == EventTypes.PowerLevels:
_check_power_levels(event, auth_events)
_check_power_levels(room_version_obj, event, auth_events)
if event.type == EventTypes.Redaction:
check_redaction(room_version_obj, event, auth_events)
@ -442,7 +442,7 @@ def check_redaction(room_version_obj: RoomVersion, event, auth_events):
raise AuthError(403, "You don't have permission to redact events")
def _check_power_levels(event, auth_events):
def _check_power_levels(room_version_obj, event, auth_events):
user_list = event.content.get("users", {})
# Validate users
for k, v in user_list.items():
@ -484,6 +484,14 @@ def _check_power_levels(event, auth_events):
for ev_id in set(list(old_list) + list(new_list)):
levels_to_check.append((ev_id, "events"))
# MSC2209 specifies these checks should also be done for the "notifications"
# key.
if room_version_obj.limit_notifications_power_levels:
old_list = current_state.content.get("notifications", {})
new_list = event.content.get("notifications", {})
for ev_id in set(list(old_list) + list(new_list)):
levels_to_check.append((ev_id, "notifications"))
old_state = current_state.content
new_state = event.content

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@ -165,6 +165,39 @@ class EventAuthTestCase(unittest.TestCase):
do_sig_check=False,
)
def test_msc2209(self):
"""
Notifications power levels get checked due to MSC2209.
"""
creator = "@creator:example.com"
pleb = "@joiner:example.com"
auth_events = {
("m.room.create", ""): _create_event(creator),
("m.room.member", creator): _join_event(creator),
("m.room.power_levels", ""): _power_levels_event(
creator, {"state_default": "30", "users": {pleb: "30"}}
),
("m.room.member", pleb): _join_event(pleb),
}
# pleb should be able to modify the notifications power level.
event_auth.check(
RoomVersions.V1,
_power_levels_event(pleb, {"notifications": {"room": 100}}),
auth_events,
do_sig_check=False,
)
# But an MSC2209 room rejects this change.
with self.assertRaises(AuthError):
event_auth.check(
RoomVersions.MSC2209_DEV,
_power_levels_event(pleb, {"notifications": {"room": 100}}),
auth_events,
do_sig_check=False,
)
# helpers for making events