Prevent any update of local commitment transaction once signed

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

diff --git a/lightning/src/ln/channelmonitor.rs b/lightning/src/ln/channelmonitor.rs
index 8b116b9d63fc7ab68dfcf2a26a8ffbc3d076f948..2fa416edb2dd79f26c8c0f5433b31e60c135bc2b 100644 (file)
--- a/lightning/src/ln/channelmonitor.rs
+++ b/lightning/src/ln/channelmonitor.rs
@@ -1098,7 +1098,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        onchain_detection: onchain_detection,
                        their_htlc_base_key: Some(their_htlc_base_key.clone()),
                        their_delayed_payment_base_key: Some(their_delayed_payment_base_key.clone()),
-                       funding_redeemscript: Some(funding_redeemscript),
+                       funding_redeemscript: Some(funding_redeemscript.clone()),
                        channel_value_satoshis: Some(channel_value_satoshis),
                        their_cur_revocation_points: None,
 
@@ -1121,7 +1121,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        onchain_events_waiting_threshold_conf: HashMap::new(),
                        outputs_to_watch: HashMap::new(),
 
-                       onchain_tx_handler: OnchainTxHandler::new(destination_script.clone(), keys, logger.clone()),
+                       onchain_tx_handler: OnchainTxHandler::new(destination_script.clone(), keys, funding_redeemscript, logger.clone()),
 
                        last_block_hash: Default::default(),
                        secp_ctx: Secp256k1::new(),
@@ -1241,6 +1241,14 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                if self.their_to_self_delay.is_none() {
                        return Err(MonitorUpdateError("Got a local commitment tx info update before we'd set basic information about the channel"));
                }
+               // Returning a monitor error before updating tracking points means in case of using
+               // a concurrent watchtower implementation for same channel, if this one doesn't
+               // reject update as we do, you MAY have the latest local valid commitment tx onchain
+               // for which you want to spend outputs. We're NOT robust again this scenario right
+               // now but we should consider it later.
+               if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx.clone()) {
+                       return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
+               }
                self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
                self.current_local_signed_commitment_tx = Some(LocalSignedTx {
                        txid: commitment_tx.txid(),