Reject rumors of channels that are from one node back to itself

[rust-lightning] / src / ln / router.rs

diff --git a/src/ln/router.rs b/src/ln/router.rs
index e249913ec579efbe11616e02f57b8e5aff7e0c4e..6bc319d59b8145de6162f47c7c78d746fd318a12 100644 (file)
--- a/src/ln/router.rs
+++ b/src/ln/router.rs
@@ -3,6 +3,8 @@ use secp256k1::{Secp256k1,Message};
 use secp256k1;
 
 use bitcoin::util::hash::Sha256dHash;
+use bitcoin::blockdata::script::Builder;
+use bitcoin::blockdata::opcodes;
 
 use chain::chaininterface::{ChainError, ChainWatchInterface};
 use ln::channelmanager;
@@ -197,6 +199,10 @@ impl RoutingMessageHandler for Router {
        }
 
        fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
+               if msg.contents.node_id_1 == msg.contents.node_id_2 || msg.contents.bitcoin_key_1 == msg.contents.bitcoin_key_2 {
+                       return Err(HandleError{err: "Channel announcement node had a channel with itself", action: Some(ErrorAction::IgnoreError)});
+               }
+
                let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
                secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
@@ -209,10 +215,18 @@ impl RoutingMessageHandler for Router {
 
                match self.chain_monitor.get_chain_utxo(msg.contents.chain_hash, msg.contents.short_channel_id) {
                        Ok((script_pubkey, _value)) => {
-                               //TODO: Check if script_pubkey matches bitcoin_key_1 and bitcoin_key_2
+                               let expected_script = Builder::new().push_opcode(opcodes::All::OP_PUSHNUM_2)
+                                                                   .push_slice(&msg.contents.bitcoin_key_1.serialize())
+                                                                   .push_slice(&msg.contents.bitcoin_key_2.serialize())
+                                                                   .push_opcode(opcodes::All::OP_PUSHNUM_2).push_opcode(opcodes::All::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
+                               if script_pubkey != expected_script {
+                                       return Err(HandleError{err: "Channel announcement keys didn't match on-chain script", action: Some(ErrorAction::IgnoreError)});
+                               }
+                               //TODO: Check if value is worth storing, use it to inform routing, and compare it
+                               //to the new HTLC max field in channel_update
                        },
                        Err(ChainError::NotSupported) => {
-                               // Tenatively accept, potentially exposing us to DoS attacks
+                               // Tentatively accept, potentially exposing us to DoS attacks
                        },
                        Err(ChainError::NotWatched) => {
                                return Err(HandleError{err: "Channel announced on an unknown chain", action: Some(ErrorAction::IgnoreError)});