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Merge pull request #4499 from matrix-org/erikj/redactions_eiah

Implement rechecking of redactions for room versions v3
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Erik Johnston 2019-01-29 23:07:00 +00:00 committed by GitHub
commit e12313ba25
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8 changed files with 77 additions and 16 deletions

1
changelog.d/4499.feature Normal file
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@ -0,0 +1 @@
Add support for room version 3

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@ -616,7 +616,7 @@ class Auth(object):
defer.returnValue(auth_ids)
def check_redaction(self, event, auth_events):
def check_redaction(self, room_version, event, auth_events):
"""Check whether the event sender is allowed to redact the target event.
Returns:
@ -629,7 +629,7 @@ class Auth(object):
AuthError if the event sender is definitely not allowed to redact
the target event.
"""
return event_auth.check_redaction(event, auth_events)
return event_auth.check_redaction(room_version, event, auth_events)
@defer.inlineCallbacks
def check_can_change_room_list(self, room_id, user):

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@ -104,7 +104,7 @@ class ThirdPartyEntityKind(object):
class RoomVersions(object):
V1 = "1"
V2 = "2"
VDH_TEST = "vdh-test-version"
V3 = "3" # Not currently fully supported, so we don't add to known versions below
STATE_V2_TEST = "state-v2-test"
@ -116,7 +116,6 @@ DEFAULT_ROOM_VERSION = RoomVersions.V1
KNOWN_ROOM_VERSIONS = {
RoomVersions.V1,
RoomVersions.V2,
RoomVersions.VDH_TEST,
RoomVersions.STATE_V2_TEST,
}

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@ -26,6 +26,7 @@ from synapse.api.constants import (
EventTypes,
JoinRules,
Membership,
RoomVersions,
)
from synapse.api.errors import AuthError, EventSizeError, SynapseError
from synapse.types import UserID, get_domain_from_id
@ -177,7 +178,7 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
_check_power_levels(event, auth_events)
if event.type == EventTypes.Redaction:
check_redaction(event, auth_events)
check_redaction(room_version, event, auth_events)
logger.debug("Allowing! %s", event)
@ -431,7 +432,7 @@ def _can_send_event(event, auth_events):
return True
def check_redaction(event, auth_events):
def check_redaction(room_version, event, auth_events):
"""Check whether the event sender is allowed to redact the target event.
Returns:
@ -451,10 +452,16 @@ def check_redaction(event, auth_events):
if user_level >= redact_level:
return False
redacter_domain = get_domain_from_id(event.event_id)
redactee_domain = get_domain_from_id(event.redacts)
if redacter_domain == redactee_domain:
if room_version in (RoomVersions.V1, RoomVersions.V2,):
redacter_domain = get_domain_from_id(event.event_id)
redactee_domain = get_domain_from_id(event.redacts)
if redacter_domain == redactee_domain:
return True
elif room_version == RoomVersions.V3:
event.internal_metadata.recheck_redaction = True
return True
else:
raise RuntimeError("Unrecognized room version %r" % (room_version,))
raise AuthError(
403,

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@ -62,6 +62,21 @@ class _EventInternalMetadata(object):
"""
return getattr(self, "send_on_behalf_of", None)
def need_to_check_redaction(self):
"""Whether the redaction event needs to be rechecked when fetching
from the database.
Starting in room v3 redaction events are accepted up front, and later
checked to see if the redacter and redactee's domains match.
If the sender of the redaction event is allowed to redact any event
due to auth rules, then this will always return false.
Returns:
bool
"""
return getattr(self, "recheck_redaction", False)
def _event_dict_property(key):
# We want to be able to use hasattr with the event dict properties.
@ -328,8 +343,7 @@ def room_version_to_event_format(room_version):
raise RuntimeError("Unrecognized room version %s" % (room_version,))
if room_version in (
RoomVersions.V1, RoomVersions.V2, RoomVersions.VDH_TEST,
RoomVersions.STATE_V2_TEST,
RoomVersions.V1, RoomVersions.V2, RoomVersions.STATE_V2_TEST,
):
return EventFormatVersions.V1
else:

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@ -745,7 +745,8 @@ class EventCreationHandler(object):
auth_events = {
(e.type, e.state_key): e for e in auth_events.values()
}
if self.auth.check_redaction(event, auth_events=auth_events):
room_version = yield self.store.get_room_version(event.room_id)
if self.auth.check_redaction(room_version, event, auth_events=auth_events):
original_event = yield self.store.get_event(
event.redacts,
check_redacted=False,
@ -759,6 +760,9 @@ class EventCreationHandler(object):
"You don't have permission to redact events"
)
# We've already checked.
event.internal_metadata.recheck_redaction = False
if event.type == EventTypes.Create:
prev_state_ids = yield context.get_prev_state_ids(self.store)
if prev_state_ids:

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@ -608,7 +608,7 @@ def resolve_events_with_store(room_version, state_sets, event_map, state_res_sto
state_sets, event_map, state_res_store.get_events,
)
elif room_version in (
RoomVersions.VDH_TEST, RoomVersions.STATE_V2_TEST, RoomVersions.V2,
RoomVersions.STATE_V2_TEST, RoomVersions.V2,
):
return v2.resolve_events_with_store(
room_version, state_sets, event_map, state_res_store,

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@ -21,13 +21,14 @@ from canonicaljson import json
from twisted.internet import defer
from synapse.api.constants import EventFormatVersions
from synapse.api.constants import EventFormatVersions, EventTypes
from synapse.api.errors import NotFoundError
from synapse.events import FrozenEvent, event_type_from_format_version # noqa: F401
# these are only included to make the type annotations work
from synapse.events.snapshot import EventContext # noqa: F401
from synapse.events.utils import prune_event
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.types import get_domain_from_id
from synapse.util.logcontext import (
LoggingContext,
PreserveLoggingContext,
@ -162,7 +163,6 @@ class EventsWorkerStore(SQLBaseStore):
missing_events = yield self._enqueue_events(
missing_events_ids,
check_redacted=check_redacted,
allow_rejected=allow_rejected,
)
@ -174,6 +174,29 @@ class EventsWorkerStore(SQLBaseStore):
if not entry:
continue
# Starting in room version v3, some redactions need to be rechecked if we
# didn't have the redacted event at the time, so we recheck on read
# instead.
if not allow_rejected and entry.event.type == EventTypes.Redaction:
if entry.event.internal_metadata.need_to_check_redaction():
orig = yield self.get_event(
entry.event.redacts,
allow_none=True,
allow_rejected=True,
get_prev_content=False,
)
expected_domain = get_domain_from_id(entry.event.sender)
if orig and get_domain_from_id(orig.sender) == expected_domain:
# This redaction event is allowed. Mark as not needing a
# recheck.
entry.event.internal_metadata.recheck_redaction = False
else:
# We don't have the event that is being redacted, so we
# assume that the event isn't authorized for now. (If we
# later receive the event, then we will always redact
# it anyway, since we have this redaction)
continue
if allow_rejected or not entry.event.rejected_reason:
if check_redacted and entry.redacted_event:
event = entry.redacted_event
@ -310,7 +333,7 @@ class EventsWorkerStore(SQLBaseStore):
self.hs.get_reactor().callFromThread(fire, event_list, e)
@defer.inlineCallbacks
def _enqueue_events(self, events, check_redacted=True, allow_rejected=False):
def _enqueue_events(self, events, allow_rejected=False):
"""Fetches events from the database using the _event_fetch_list. This
allows batch and bulk fetching of events - it allows us to fetch events
without having to create a new transaction for each request for events.
@ -443,6 +466,19 @@ class EventsWorkerStore(SQLBaseStore):
# will serialise this field correctly
redacted_event.unsigned["redacted_because"] = because
# Starting in room version v3, some redactions need to be
# rechecked if we didn't have the redacted event at the
# time, so we recheck on read instead.
if because.internal_metadata.need_to_check_redaction():
expected_domain = get_domain_from_id(original_ev.sender)
if get_domain_from_id(because.sender) == expected_domain:
# This redaction event is allowed. Mark as not needing a
# recheck.
because.internal_metadata.recheck_redaction = False
else:
# Senders don't match, so the event isn't actually redacted
redacted_event = None
cache_entry = _EventCacheEntry(
event=original_ev,
redacted_event=redacted_event,