diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index c80f4c61bc..e1539bd0e0 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -20,6 +20,13 @@ from .units import Edu
from synapse.util.logutils import log_function
from synapse.events import FrozenEvent
+from synapse.events.utils import prune_event
+
+from syutil.jsonutil import encode_canonical_json
+
+from synapse.crypto.event_signing import check_event_content_hash
+
+from synapse.api.errors import SynapseError
import logging
@@ -126,6 +133,11 @@ class FederationClient(object):
for p in transaction_data["pdus"]
]
+ for i, pdu in enumerate(pdus):
+ pdus[i] = yield self._check_sigs_and_hash(pdu)
+
+ # FIXME: We should handle signature failures more gracefully.
+
defer.returnValue(pdus)
@defer.inlineCallbacks
@@ -159,6 +171,22 @@ class FederationClient(object):
transaction_data = yield self.transport_layer.get_event(
destination, event_id
)
+
+ logger.debug("transaction_data %r", transaction_data)
+
+ pdu_list = [
+ self.event_from_pdu_json(p, outlier=outlier)
+ for p in transaction_data["pdus"]
+ ]
+
+ if pdu_list:
+ pdu = pdu_list[0]
+
+ # Check signatures are correct.
+ pdu = yield self._check_sigs_and_hash(pdu)
+
+ break
+
except Exception as e:
logger.info(
"Failed to get PDU %s from %s because %s",
@@ -166,18 +194,6 @@ class FederationClient(object):
)
continue
- logger.debug("transaction_data %r", transaction_data)
-
- pdu_list = [
- self.event_from_pdu_json(p, outlier=outlier)
- for p in transaction_data["pdus"]
- ]
-
- if pdu_list:
- pdu = pdu_list[0]
- # TODO: We need to check signatures here
- break
-
defer.returnValue(pdu)
@defer.inlineCallbacks
@@ -208,6 +224,16 @@ 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)
+
+ # 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.
+
defer.returnValue((pdus, auth_chain))
@defer.inlineCallbacks
@@ -222,6 +248,11 @@ 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)
+
+ # FIXME: We should handle signature failures more gracefully.
+
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue(auth_chain)
@@ -260,6 +291,16 @@ 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)
+
+ # 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.
+
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue({
@@ -281,7 +322,48 @@ class FederationClient(object):
logger.debug("Got response to send_invite: %s", pdu_dict)
- defer.returnValue(self.event_from_pdu_json(pdu_dict))
+ pdu = self.event_from_pdu_json(pdu_dict)
+
+ # Check signatures are correct.
+ pdu = yield self._check_sigs_and_hash(pdu)
+
+ # FIXME: We should handle signature failures more gracefully.
+
+ defer.returnValue(pdu)
+
+ @defer.inlineCallbacks
+ def query_auth(self, destination, room_id, event_id, local_auth):
+ """
+ Params:
+ destination (str)
+ event_it (str)
+ local_auth (list)
+ """
+ time_now = self._clock.time_msec()
+
+ send_content = {
+ "auth_chain": [e.get_pdu_json(time_now) for e in local_auth],
+ }
+
+ code, content = yield self.transport_layer.send_query_auth(
+ destination=destination,
+ room_id=room_id,
+ event_id=event_id,
+ content=send_content,
+ )
+
+ auth_chain = [
+ (yield self._check_sigs_and_hash(self.event_from_pdu_json(e)))
+ for e in content["auth_chain"]
+ ]
+
+ ret = {
+ "auth_chain": auth_chain,
+ "rejects": content.get("rejects", []),
+ "missing": content.get("missing", []),
+ }
+
+ defer.returnValue(ret)
def event_from_pdu_json(self, pdu_json, outlier=False):
event = FrozenEvent(
@@ -291,3 +373,37 @@ class FederationClient(object):
event.internal_metadata.outlier = outlier
return event
+
+ @defer.inlineCallbacks
+ 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)
|
