Don't fail an entire request if one of the returned events fails a signature check. If an event does fail a signature check, look in the local database and request it from the originator.

This commit is contained in:
Erik Johnston 2015-02-02 16:56:01 +00:00
parent 365e007bee
commit 941f59101b
2 changed files with 94 additions and 34 deletions

View File

@ -224,17 +224,17 @@ class FederationClient(object):
for p in result.get("auth_chain", [])
]
for i, pdu in enumerate(pdus):
pdus[i] = yield self._check_sigs_and_hash(pdu)
signed_pdus = yield self._check_sigs_and_hash_and_fetch(
pdus, outlier=True
)
# FIXME: We should handle signature failures more gracefully.
signed_auth = yield self._check_sigs_and_hash_and_fetch(
auth_chain, outlier=True
)
for i, pdu in enumerate(auth_chain):
auth_chain[i] = yield self._check_sigs_and_hash(pdu)
signed_auth.sort(key=lambda e: e.depth)
# FIXME: We should handle signature failures more gracefully.
defer.returnValue((pdus, auth_chain))
defer.returnValue((signed_pdus, signed_auth))
@defer.inlineCallbacks
@log_function
@ -248,14 +248,13 @@ class FederationClient(object):
for p in res["auth_chain"]
]
for i, pdu in enumerate(auth_chain):
auth_chain[i] = yield self._check_sigs_and_hash(pdu)
signed_auth = yield self._check_sigs_and_hash_and_fetch(
auth_chain, outlier=True
)
# FIXME: We should handle signature failures more gracefully.
signed_auth.sort(key=lambda e: e.depth)
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue(auth_chain)
defer.returnValue(signed_auth)
@defer.inlineCallbacks
def make_join(self, destination, room_id, user_id):
@ -291,21 +290,19 @@ class FederationClient(object):
for p in content.get("auth_chain", [])
]
for i, pdu in enumerate(state):
state[i] = yield self._check_sigs_and_hash(pdu)
signed_state = yield self._check_sigs_and_hash_and_fetch(
state, outlier=True
)
# FIXME: We should handle signature failures more gracefully.
for i, pdu in enumerate(auth_chain):
auth_chain[i] = yield self._check_sigs_and_hash(pdu)
# FIXME: We should handle signature failures more gracefully.
signed_auth = yield self._check_sigs_and_hash_and_fetch(
auth_chain, outlier=True
)
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue({
"state": state,
"auth_chain": auth_chain,
"state": signed_state,
"auth_chain": signed_auth,
})
@defer.inlineCallbacks
@ -353,12 +350,18 @@ class FederationClient(object):
)
auth_chain = [
(yield self._check_sigs_and_hash(self.event_from_pdu_json(e)))
self.event_from_pdu_json(e)
for e in content["auth_chain"]
]
signed_auth = yield self._check_sigs_and_hash_and_fetch(
auth_chain, outlier=True
)
signed_auth.sort(key=lambda e: e.depth)
ret = {
"auth_chain": auth_chain,
"auth_chain": signed_auth,
"rejects": content.get("rejects", []),
"missing": content.get("missing", []),
}
@ -374,6 +377,58 @@ class FederationClient(object):
return event
@defer.inlineCallbacks
def _check_sigs_and_hash_and_fetch(self, pdus, outlier=False):
"""Takes a list of PDUs and checks the signatures and hashs of each
one. If a PDU fails its signature check then we check if we have it in
the database and if not then request if from the originating server of
that PDU.
If a PDU fails its content hash check then it is redacted.
The given list of PDUs are not modified, instead the function returns
a new list.
Args:
pdu (list)
outlier (bool)
Returns:
Deferred : A list of PDUs that have valid signatures and hashes.
"""
signed_pdus = []
for pdu in pdus:
try:
new_pdu = yield self._check_sigs_and_hash(pdu)
signed_pdus.append(new_pdu)
except SynapseError:
# FIXME: We should handle signature failures more gracefully.
# Check local db.
new_pdu = yield self.store.get_event(
pdu.event_id,
allow_rejected=True
)
if new_pdu:
signed_pdus.append(new_pdu)
continue
# Check pdu.origin
new_pdu = yield self.get_pdu(
destinations=[pdu.origin],
event_id=pdu.event_id,
outlier=outlier,
)
if new_pdu:
signed_pdus.append(new_pdu)
continue
logger.warn("Failed to find copy of %s with valid signature")
defer.returnValue(signed_pdus)
@defer.inlineCallbacks
def _check_sigs_and_hash(self, pdu):
"""Throws a SynapseError if the PDU does not have the correct

View File

@ -128,16 +128,21 @@ class DataStore(RoomMemberStore, RoomStore,
pass
@defer.inlineCallbacks
def get_event(self, event_id, allow_none=False):
events = yield self._get_events([event_id])
def get_event(self, event_id, check_redacted=True,
get_prev_content=False, allow_rejected=False,
allow_none=False):
event = yield self.runInteraction(
"get_event", self._get_event_txn,
event_id,
check_redacted=check_redacted,
get_prev_content=get_prev_content,
allow_rejected=allow_rejected,
)
if not events:
if allow_none:
defer.returnValue(None)
else:
if not event and not allow_none:
raise RuntimeError("Could not find event %s" % (event_id,))
defer.returnValue(events[0])
defer.returnValue(event)
@log_function
def _persist_event_txn(self, txn, event, context, backfilled,