def callback(_, pdu, redacted):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json())
return redacted
return pdu
def _check_sigs_and_hash(self, pdu):
"""Throws a SynapseError if the PDU does not have the correct
signatures.
Returns:
FrozenEvent: Either the given event or it redacted if it failed the
content hash check.
"""
# Check signatures are correct.
redacted_event = prune_event(pdu)
redacted_pdu_json = redacted_event.get_pdu_json()
try:
yield self.keyring.verify_json_for_server(pdu.origin,
redacted_pdu_json)
except SynapseError:
logger.warn(
"Signature check failed for %s redacted to %s",
encode_canonical_json(pdu.get_pdu_json()),
encode_canonical_json(redacted_pdu_json),
)
raise
if not check_event_content_hash(pdu):
logger.warn("Event content has been tampered, redacting %s, %s",
pdu.event_id, encode_canonical_json(pdu.get_dict()))
defer.returnValue(redacted_event)
defer.returnValue(pdu)
def _check_sigs_and_hash(self, pdu):
"""Throws a SynapseError if the PDU does not have the correct
signatures.
Returns:
FrozenEvent: Either the given event or it redacted if it failed the
content hash check.
"""
# Check signatures are correct.
redacted_event = prune_event(pdu)
redacted_pdu_json = redacted_event.get_pdu_json()
try:
yield self.keyring.verify_json_for_server(
pdu.origin, redacted_pdu_json
)
except SynapseError:
logger.warn(
"Signature check failed for %s redacted to %s",
encode_canonical_json(pdu.get_pdu_json()),
encode_canonical_json(redacted_pdu_json),
)
raise
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s, %s",
pdu.event_id, encode_canonical_json(pdu.get_dict())
)
defer.returnValue(redacted_event)
defer.returnValue(pdu)
def callback(_, pdu):
with logcontext.PreserveLoggingContext(ctx):
if not check_event_content_hash(pdu):
# let's try to distinguish between failures because the event was
# redacted (which are somewhat expected) vs actual ball-tampering
# incidents.
#
# This is just a heuristic, so we just assume that if the keys are
# about the same between the redacted and received events, then the
# received event was probably a redacted copy (but we then use our
# *actual* redacted copy to be on the safe side.)
redacted_event = prune_event(pdu)
if (set(redacted_event.keys()) == set(pdu.keys())
and set(six.iterkeys(redacted_event.content))
== set(six.iterkeys(pdu.content))):
logger.info(
"Event %s seems to have been redacted; using our redacted "
"copy",
pdu.event_id,
)
else:
logger.warning(
"Event %s content has been tampered, redacting",
pdu.event_id,
pdu.get_pdu_json(),
)
return redacted_event
if self.spam_checker.check_event_for_spam(pdu):
logger.warn("Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json())
return prune_event(pdu)
return pdu
async def _check_sigs_and_hash(
self, room_version: RoomVersion, pdu: EventBase
) -> EventBase:
"""Checks that event is correctly signed by the sending server.
Also checks the content hash, and redacts the event if there is a mismatch.
Also runs the event through the spam checker; if it fails, redacts the event
and flags it as soft-failed.
Args:
room_version: The room version of the PDU
pdu: the event to be checked
Returns:
* the original event if the checks pass
* a redacted version of the event (if the signature
matched but the hash did not). In this case a warning will be logged.
Raises:
InvalidEventSignatureError if the signature check failed. Nothing
will be logged in this case.
"""
await _check_sigs_on_pdu(self.keyring, room_version, pdu)
if not check_event_content_hash(pdu):
# let's try to distinguish between failures because the event was
# redacted (which are somewhat expected) vs actual ball-tampering
# incidents.
#
# This is just a heuristic, so we just assume that if the keys are
# about the same between the redacted and received events, then the
# received event was probably a redacted copy (but we then use our
# *actual* redacted copy to be on the safe side.)
redacted_event = prune_event(pdu)
if set(redacted_event.keys()) == set(pdu.keys()) and set(
redacted_event.content.keys()
) == set(pdu.content.keys()):
logger.debug(
"Event %s seems to have been redacted; using our redacted copy",
pdu.event_id,
)
else:
logger.warning(
"Event %s content has been tampered, redacting",
pdu.event_id,
)
return redacted_event
spam_check = await self.spam_checker.check_event_for_spam(pdu)
if spam_check != self.spam_checker.NOT_SPAM:
logger.warning("Event contains spam, soft-failing %s", pdu.event_id)
# we redact (to save disk space) as well as soft-failing (to stop
# using the event in prev_events).
redacted_event = prune_event(pdu)
redacted_event.internal_metadata.soft_failed = True
return redacted_event
return pdu
def callback(_, pdu, redacted):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
return pdu
async def _check_sigs_and_hash(self, room_version: RoomVersion,
pdu: EventBase) -> EventBase:
"""Checks that event is correctly signed by the sending server.
Args:
room_version: The room version of the PDU
pdu: the event to be checked
Returns:
* the original event if the checks pass
* a redacted version of the event (if the signature
matched but the hash did not)
* throws a SynapseError if the signature check failed."""
try:
await _check_sigs_on_pdu(self.keyring, room_version, pdu)
except SynapseError as e:
logger.warning(
"Signature check failed for %s: %s",
pdu.event_id,
e,
)
raise
if not check_event_content_hash(pdu):
# let's try to distinguish between failures because the event was
# redacted (which are somewhat expected) vs actual ball-tampering
# incidents.
#
# This is just a heuristic, so we just assume that if the keys are
# about the same between the redacted and received events, then the
# received event was probably a redacted copy (but we then use our
# *actual* redacted copy to be on the safe side.)
redacted_event = prune_event(pdu)
if set(redacted_event.keys()) == set(pdu.keys()) and set(
redacted_event.content.keys()) == set(pdu.content.keys()):
logger.info(
"Event %s seems to have been redacted; using our redacted copy",
pdu.event_id,
)
else:
logger.warning(
"Event %s content has been tampered, redacting",
pdu.event_id,
)
return redacted_event
result = await self.spam_checker.check_event_for_spam(pdu)
if result:
logger.warning("Event contains spam, soft-failing %s",
pdu.event_id)
# we redact (to save disk space) as well as soft-failing (to stop
# using the event in prev_events).
redacted_event = prune_event(pdu)
redacted_event.internal_metadata.soft_failed = True
return redacted_event
return pdu
def callback(_, pdu):
with logcontext.PreserveLoggingContext(ctx):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json())
return prune_event(pdu)
if self.spam_checker.check_event_for_spam(pdu):
logger.warn("Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json())
return prune_event(pdu)
return pdu
def callback(_, pdu, redacted):
with logcontext.PreserveLoggingContext(ctx):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
if self.spam_checker.check_event_for_spam(pdu):
logger.warn(
"Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
return pdu
def main():
parser = argparse.ArgumentParser()
parser.add_argument(
"input_json", nargs="?", type=argparse.FileType('r'), default=sys.stdin
)
args = parser.parse_args()
logging.basicConfig()
event_json = dictobj(json.load(args.input_json))
algorithms = {"sha256": hashlib.sha256}
for alg_name in event_json.hashes:
if check_event_content_hash(event_json, algorithms[alg_name]):
print("PASS content hash %s" % (alg_name,))
else:
print("FAIL content hash %s" % (alg_name,))
for algorithm in algorithms.values():
name, h_bytes = compute_event_reference_hash(event_json, algorithm)
print("Reference hash %s: %s" % (name, encode_base64(h_bytes)))
def main():
parser = argparse.ArgumentParser()
parser.add_argument("input_json",
nargs="?",
type=argparse.FileType('r'),
default=sys.stdin)
args = parser.parse_args()
logging.basicConfig()
event_json = dictobj(json.load(args.input_json))
algorithms = {"sha256": hashlib.sha256}
for alg_name in event_json.hashes:
if check_event_content_hash(event_json, algorithms[alg_name]):
print("PASS content hash %s" % (alg_name, ))
else:
print("FAIL content hash %s" % (alg_name, ))
for algorithm in algorithms.values():
name, h_bytes = compute_event_reference_hash(event_json, algorithm)
print("Reference hash %s: %s" % (name, encode_base64(h_bytes)))
def callback(_, pdu):
with logcontext.PreserveLoggingContext(ctx):
if not check_event_content_hash(pdu):
# let's try to distinguish between failures because the event was
# redacted (which are somewhat expected) vs actual ball-tampering
# incidents.
#
# This is just a heuristic, so we just assume that if the keys are
# about the same between the redacted and received events, then the
# received event was probably a redacted copy (but we then use our
# *actual* redacted copy to be on the safe side.)
redacted_event = prune_event(pdu)
if (
set(redacted_event.keys()) == set(pdu.keys()) and
set(six.iterkeys(redacted_event.content))
== set(six.iterkeys(pdu.content))
):
logger.info(
"Event %s seems to have been redacted; using our redacted "
"copy",
pdu.event_id,
)
else:
logger.warning(
"Event %s content has been tampered, redacting",
pdu.event_id, pdu.get_pdu_json(),
)
return redacted_event
if self.spam_checker.check_event_for_spam(pdu):
logger.warn(
"Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return prune_event(pdu)
return pdu
def on_receive_pdu(self,
origin,
pdu,
backfilled,
state=None,
auth_chain=None):
""" Called by the ReplicationLayer when we have a new pdu. We need to
do auth checks and put it through the StateHandler.
"""
event = pdu
logger.debug("Got event: %s", event.event_id)
# If we are currently in the process of joining this room, then we
# queue up events for later processing.
if event.room_id in self.room_queues:
self.room_queues[event.room_id].append((pdu, origin))
return
logger.debug("Processing event: %s", event.event_id)
redacted_event = prune_event(event)
redacted_pdu_json = redacted_event.get_pdu_json()
try:
yield self.keyring.verify_json_for_server(event.origin,
redacted_pdu_json)
except SynapseError as e:
logger.warn(
"Signature check failed for %s redacted to %s",
encode_canonical_json(pdu.get_pdu_json()),
encode_canonical_json(redacted_pdu_json),
)
raise FederationError(
"ERROR",
e.code,
e.msg,
affected=event.event_id,
)
if not check_event_content_hash(event):
logger.warn("Event content has been tampered, redacting %s, %s",
event.event_id,
encode_canonical_json(event.get_dict()))
event = redacted_event
logger.debug("Event: %s", event)
# FIXME (erikj): Awful hack to make the case where we are not currently
# in the room work
current_state = None
is_in_room = yield self.auth.check_host_in_room(
event.room_id, self.server_name)
if not is_in_room and not event.internal_metadata.outlier:
logger.debug("Got event for room we're not in.")
replication = self.replication_layer
if not state:
state, auth_chain = yield replication.get_state_for_context(
origin,
context=event.room_id,
event_id=event.event_id,
)
if not auth_chain:
auth_chain = yield replication.get_event_auth(
origin,
context=event.room_id,
event_id=event.event_id,
)
for e in auth_chain:
e.internal_metadata.outlier = True
try:
yield self._handle_new_event(e, fetch_auth_from=origin)
except:
logger.exception(
"Failed to handle auth event %s",
e.event_id,
)
current_state = state
if state:
for e in state:
logging.info("A :) %r", e)
e.internal_metadata.outlier = True
try:
yield self._handle_new_event(e)
except:
logger.exception(
"Failed to handle state event %s",
e.event_id,
)
try:
yield self._handle_new_event(
event,
state=state,
backfilled=backfilled,
current_state=current_state,
)
except AuthError as e:
raise FederationError(
"ERROR",
e.code,
e.msg,
affected=event.event_id,
)
# if we're receiving valid events from an origin,
# it's probably a good idea to mark it as not in retry-state
# for sending (although this is a bit of a leap)
retry_timings = yield self.store.get_destination_retry_timings(origin)
if (retry_timings and retry_timings.retry_last_ts):
self.store.set_destination_retry_timings(origin, 0, 0)
room = yield self.store.get_room(event.room_id)
if not room:
try:
yield self.store.store_room(
room_id=event.room_id,
room_creator_user_id="",
is_public=False,
)
except StoreError:
logger.exception("Failed to store room.")
if not backfilled:
extra_users = []
if event.type == EventTypes.Member:
target_user_id = event.state_key
target_user = self.hs.parse_userid(target_user_id)
extra_users.append(target_user)
yield self.notifier.on_new_room_event(event,
extra_users=extra_users)
if event.type == EventTypes.Member:
if event.membership == Membership.JOIN:
user = self.hs.parse_userid(event.state_key)
yield self.distributor.fire("user_joined_room",
user=user,
room_id=event.room_id)
def on_receive_pdu(self, origin, pdu, backfilled, state=None):
""" Called by the ReplicationLayer when we have a new pdu. We need to
do auth checks and put it through the StateHandler.
"""
event = pdu
logger.debug("Got event: %s", event.event_id)
# If we are currently in the process of joining this room, then we
# queue up events for later processing.
if event.room_id in self.room_queues:
self.room_queues[event.room_id].append((pdu, origin))
return
logger.debug("Processing event: %s", event.event_id)
redacted_event = prune_event(event)
redacted_pdu_json = redacted_event.get_pdu_json()
try:
yield self.keyring.verify_json_for_server(
event.origin, redacted_pdu_json
)
except SynapseError as e:
logger.warn(
"Signature check failed for %s redacted to %s",
encode_canonical_json(pdu.get_pdu_json()),
encode_canonical_json(redacted_pdu_json),
)
raise FederationError(
"ERROR",
e.code,
e.msg,
affected=event.event_id,
)
if not check_event_content_hash(event):
logger.warn(
"Event content has been tampered, redacting %s, %s",
event.event_id, encode_canonical_json(event.get_full_dict())
)
event = redacted_event
logger.debug("Event: %s", event)
# FIXME (erikj): Awful hack to make the case where we are not currently
# in the room work
current_state = None
is_in_room = yield self.auth.check_host_in_room(
event.room_id,
self.server_name
)
if not is_in_room and not event.outlier:
logger.debug("Got event for room we're not in.")
replication_layer = self.replication_layer
auth_chain = yield replication_layer.get_event_auth(
origin,
context=event.room_id,
event_id=event.event_id,
)
for e in auth_chain:
e.outlier = True
try:
yield self._handle_new_event(e, fetch_missing=False)
except:
logger.exception(
"Failed to parse auth event %s",
e.event_id,
)
if not state:
state = yield replication_layer.get_state_for_context(
origin,
context=event.room_id,
event_id=event.event_id,
)
current_state = state
if state:
for e in state:
e.outlier = True
try:
yield self._handle_new_event(e)
except:
logger.exception(
"Failed to parse state event %s",
e.event_id,
)
try:
yield self._handle_new_event(
event,
state=state,
backfilled=backfilled,
current_state=current_state,
)
except AuthError as e:
raise FederationError(
"ERROR",
e.code,
e.msg,
affected=event.event_id,
)
room = yield self.store.get_room(event.room_id)
if not room:
try:
yield self.store.store_room(
room_id=event.room_id,
room_creator_user_id="",
is_public=False,
)
except StoreError:
logger.exception("Failed to store room.")
if not backfilled:
extra_users = []
if event.type == RoomMemberEvent.TYPE:
target_user_id = event.state_key
target_user = self.hs.parse_userid(target_user_id)
extra_users.append(target_user)
yield self.notifier.on_new_room_event(
event, extra_users=extra_users
)
if event.type == RoomMemberEvent.TYPE:
if event.membership == Membership.JOIN:
user = self.hs.parse_userid(event.state_key)
yield self.distributor.fire(
"user_joined_room", user=user, room_id=event.room_id
)