fix verify_sig_for_channel_update: use raw message

electrum/lnpeer.py

@@ -118,7 +118,7 @@ class Peer(PrintError):
             #self.print_error("Received '%s'" % message_type.upper(), payload)
             return
         # raw message is needed to check signature
-        if message_type=='node_announcement':
+        if message_type in ['node_announcement', 'channel_update']:
             payload['raw'] = message
         execution_result = f(payload)
         if asyncio.iscoroutinefunction(f):

electrum/lnverifier.py

@@ -194,7 +194,7 @@ def verify_sigs_for_channel_announcement(msg_bytes: bytes) -> bool:
 
 
 def verify_sig_for_channel_update(chan_upd: dict, node_id: bytes) -> bool:
-    msg_bytes = encode_msg('channel_update', **chan_upd)
+    msg_bytes = chan_upd['raw']
     pre_hash = msg_bytes[2+64:]
     h = sha256d(pre_hash)
     sig = chan_upd['signature']