diff options
| -rw-r--r-- | synapse/federation/federation_client.py | 108 | ||||
| -rw-r--r-- | synapse/federation/federation_server.py | 89 | ||||
| -rw-r--r-- | synapse/federation/replication.py | 2 |
3 files changed, 173 insertions, 26 deletions
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index c80f4c61bc..91b44cd8b3 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 +322,14 @@ 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) def event_from_pdu_json(self, pdu_json, outlier=False): event = FrozenEvent( @@ -291,3 +339,37 @@ 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) diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 0597725ce7..fc5342afaa 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -21,6 +21,13 @@ from .units import Transaction, Edu from synapse.util.logutils import log_function from synapse.util.logcontext import PreserveLoggingContext 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 FederationError, SynapseError import logging @@ -97,8 +104,10 @@ class FederationServer(object): response = yield self.transaction_actions.have_responded(transaction) if response: - logger.debug("[%s] We've already responed to this request", - transaction.transaction_id) + logger.debug( + "[%s] We've already responed to this request", + transaction.transaction_id + ) defer.returnValue(response) return @@ -253,6 +262,9 @@ class FederationServer(object): origin, pdu.event_id, do_auth=False ) + # FIXME: Currently we fetch an event again when we already have it + # if it has been marked as an outlier. + already_seen = ( existing and ( not existing.internal_metadata.is_outlier() @@ -264,14 +276,27 @@ class FederationServer(object): defer.returnValue({}) return + # Check signature. + try: + pdu = yield self._check_sigs_and_hash(pdu) + except SynapseError as e: + raise FederationError( + "ERROR", + e.code, + e.msg, + affected=pdu.event_id, + ) + state = None auth_chain = [] have_seen = yield self.store.have_events( - [e for e, _ in pdu.prev_events] + [ev for ev, _ in pdu.prev_events] ) + fetch_state = False + # Get missing pdus if necessary. if not pdu.internal_metadata.is_outlier(): # We only backfill backwards to the min depth. @@ -311,16 +336,20 @@ class FederationServer(object): except: # TODO(erikj): Do some more intelligent retries. logger.exception("Failed to get PDU") - else: - # We need to get the state at this event, since we have reached - # a backward extremity edge. - logger.debug( - "_handle_new_pdu getting state for %s", - pdu.room_id - ) - state, auth_chain = yield self.get_state_for_room( - origin, pdu.room_id, pdu.event_id, - ) + fetch_state = True + else: + fetch_state = True + + if fetch_state: + # We need to get the state at this event, since we haven't + # processed all the prev events. + logger.debug( + "_handle_new_pdu getting state for %s", + pdu.room_id + ) + state, auth_chain = yield self.get_state_for_room( + origin, pdu.room_id, pdu.event_id, + ) ret = yield self.handler.on_receive_pdu( origin, @@ -343,3 +372,37 @@ class FederationServer(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) diff --git a/synapse/federation/replication.py b/synapse/federation/replication.py index 9ef4834927..e442c6c5d5 100644 --- a/synapse/federation/replication.py +++ b/synapse/federation/replication.py @@ -51,6 +51,8 @@ class ReplicationLayer(FederationClient, FederationServer): def __init__(self, hs, transport_layer): self.server_name = hs.hostname + self.keyring = hs.get_keyring() + self.transport_layer = transport_layer self.transport_layer.register_received_handler(self) self.transport_layer.register_request_handler(self) |