Filter out erased messages

Redact any messges sent by erased users.
This commit is contained in:
Richard van der Hoff 2018-06-07 12:28:03 +01:00
parent f1023ebf4b
commit b6faef2ad7
2 changed files with 67 additions and 21 deletions

View File

@ -495,7 +495,20 @@ class FederationHandler(BaseHandler):
for e_id, key_to_eid in event_to_state_ids.iteritems()
}
erased_senders = yield self.store.are_users_erased(
e.sender for e in events,
)
def redact_disallowed(event, state):
# if the sender has been gdpr17ed, always return a redacted
# copy of the event.
if erased_senders[event.sender]:
logger.info(
"Sender of %s has been erased, redacting",
event.event_id,
)
return prune_event(event)
if not state:
return event

View File

@ -12,15 +12,17 @@
# 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.
import itertools
import logging
import operator
from twisted.internet import defer
from synapse.api.constants import Membership, EventTypes
from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
from synapse.api.constants import EventTypes, Membership
from synapse.events.utils import prune_event
from synapse.util.logcontext import (
make_deferred_yieldable, preserve_fn,
)
logger = logging.getLogger(__name__)
@ -95,16 +97,27 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
if ignore_dict_content else []
)
erased_senders = yield store.are_users_erased((e.sender for e in events))
def allowed(event):
"""
Args:
event (synapse.events.EventBase): event to check
Returns:
None|EventBase:
None if the user cannot see this event at all
a redacted copy of the event if they can only see a redacted
version
the original event if they can see it as normal.
"""
if not event.is_state() and event.sender in ignore_list:
return False
return None
if event.event_id in always_include_ids:
return True
return event
state = event_id_to_state[event.event_id]
@ -118,10 +131,6 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
if visibility not in VISIBILITY_PRIORITY:
visibility = "shared"
# if it was world_readable, it's easy: everyone can read it
if visibility == "world_readable":
return True
# Always allow history visibility events on boundaries. This is done
# by setting the effective visibility to the least restrictive
# of the old vs new.
@ -155,7 +164,7 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
if membership == "leave" and (
prev_membership == "join" or prev_membership == "invite"
):
return True
return event
new_priority = MEMBERSHIP_PRIORITY.index(membership)
old_priority = MEMBERSHIP_PRIORITY.index(prev_membership)
@ -166,31 +175,55 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
if membership is None:
membership_event = state.get((EventTypes.Member, user_id), None)
if membership_event:
# XXX why do we do this?
# https://github.com/matrix-org/synapse/issues/3350
if membership_event.event_id not in event_id_forgotten:
membership = membership_event.membership
# if the user was a member of the room at the time of the event,
# they can see it.
if membership == Membership.JOIN:
return True
return event
# otherwise, it depends on the room visibility.
if visibility == "joined":
# we weren't a member at the time of the event, so we can't
# see this event.
return False
return None
elif visibility == "invited":
# user can also see the event if they were *invited* at the time
# of the event.
return membership == Membership.INVITE
return (
event if membership == Membership.INVITE else None
)
else:
# visibility is shared: user can also see the event if they have
# become a member since the event
elif visibility == "shared" and is_peeking:
# if the visibility is shared, users cannot see the event unless
# they have *subequently* joined the room (or were members at the
# time, of course)
#
# XXX: if the user has subsequently joined and then left again,
# ideally we would share history up to the point they left. But
# we don't know when they left.
return not is_peeking
# we don't know when they left. We just treat it as though they
# never joined, and restrict access.
return None
defer.returnValue(list(filter(allowed, events)))
# the visibility is either shared or world_readable, and the user was
# not a member at the time. We allow it, provided the original sender
# has not requested their data to be erased, in which case, we return
# a redacted version.
if erased_senders[event.sender]:
return prune_event(event)
return event
# check each event: gives an iterable[None|EventBase]
filtered_events = itertools.imap(allowed, events)
# remove the None entries
filtered_events = filter(operator.truth, filtered_events)
# we turn it into a list before returning it.
defer.returnValue(list(filtered_events))