From 7303ed65e1cb036ce410fa6157d131dfaf00171a Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 28 Nov 2017 14:06:12 +0000 Subject: [PATCH] Fix 500 when joining matrix-dev matrix-dev has an event (`$/6ANj/9QWQyd71N6DpRQPf+SDUu11+HVMeKSpMzBCwM:zemos.net`) which has no `hashes` member. Check for missing `hashes` element in events. --- synapse/crypto/event_signing.py | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/synapse/crypto/event_signing.py b/synapse/crypto/event_signing.py index 0d0e7b528..aaa3efaca 100644 --- a/synapse/crypto/event_signing.py +++ b/synapse/crypto/event_signing.py @@ -32,15 +32,22 @@ def check_event_content_hash(event, hash_algorithm=hashlib.sha256): """Check whether the hash for this PDU matches the contents""" name, expected_hash = compute_content_hash(event, hash_algorithm) logger.debug("Expecting hash: %s", encode_base64(expected_hash)) - if name not in event.hashes: + + # some malformed events lack a 'hashes'. Protect against it being missing + # or a weird type by basically treating it the same as an unhashed event. + hashes = event.get("hashes") + if not isinstance(hashes, dict): + raise SynapseError(400, "Malformed 'hashes'", Codes.UNAUTHORIZED) + + if name not in hashes: raise SynapseError( 400, "Algorithm %s not in hashes %s" % ( - name, list(event.hashes), + name, list(hashes), ), Codes.UNAUTHORIZED, ) - message_hash_base64 = event.hashes[name] + message_hash_base64 = hashes[name] try: message_hash_bytes = decode_base64(message_hash_base64) except Exception: