From: Jeffrey Czyz <jkczyz@gmail.com>
Date: Fri, 30 Jul 2021 19:28:17 +0000 (-0500)
Subject: f - Check BOLT2 compatibility in close_channel
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=d7ff37edb4fc52023d7e96b725fa586d2f64e179;p=rust-lightning

f - Check BOLT2 compatibility in close_channel
---

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index cfd0bec3d..94ce779ff 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -4451,7 +4451,7 @@ impl<Signer: Sign> Channel<Signer> {
 
 	/// Begins the shutdown process, getting a message for the remote peer and returning all
 	/// holding cell HTLCs for payment failure.
-	pub fn get_shutdown<K: Deref>(&mut self, keys_provider: &K) -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
+	pub fn get_shutdown<K: Deref>(&mut self, keys_provider: &K, their_features: &InitFeatures) -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
 	where K::Target: KeysInterface<Signer = Signer> {
 		for htlc in self.pending_outbound_htlcs.iter() {
 			if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
@@ -4471,16 +4471,30 @@ impl<Signer: Sign> Channel<Signer> {
 			return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()});
 		}
 
-		let monitor_update = if self.shutdown_scriptpubkey.is_none() {
-			self.shutdown_scriptpubkey = Some(keys_provider.get_shutdown_scriptpubkey());
-			self.latest_monitor_update_id += 1;
-			Some(ChannelMonitorUpdate {
-				update_id: self.latest_monitor_update_id,
-				updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
-					scriptpubkey: self.get_closing_scriptpubkey(),
-				}],
-			})
-		} else { None };
+		let shutdown_scriptpubkey = match self.shutdown_scriptpubkey {
+			Some(_) => None,
+			None => {
+				let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
+				if !shutdown_scriptpubkey.is_compatible(their_features) {
+					return Err(APIError::APIMisuseError { err: format!("Provided a scriptpubkey format not accepted by peer. script: ({})", shutdown_scriptpubkey.clone().into_inner().to_bytes().to_hex()) });
+				}
+				Some(shutdown_scriptpubkey)
+			},
+		};
+
+		let monitor_update = match shutdown_scriptpubkey {
+			Some(shutdown_scriptpubkey) => {
+				self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
+				self.latest_monitor_update_id += 1;
+				Some(ChannelMonitorUpdate {
+					update_id: self.latest_monitor_update_id,
+					updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
+						scriptpubkey: self.get_closing_scriptpubkey(),
+					}],
+				})
+			},
+			None => None,
+		};
 
 		// From here on out, we may not fail!
 		if self.channel_state < ChannelState::FundingSent as u32 {
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 971b4bc22..40ea3e784 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -1261,9 +1261,15 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 			let channel_state = &mut *channel_state_lock;
 			match channel_state.by_id.entry(channel_id.clone()) {
 				hash_map::Entry::Occupied(mut chan_entry) => {
-					let (shutdown_msg, monitor_update, failed_htlcs) = chan_entry.get_mut().get_shutdown(&self.keys_manager)?;
+					let counterparty_node_id = chan_entry.get().get_counterparty_node_id();
+					let their_features = {
+						let per_peer_state = self.per_peer_state.read().unwrap();
+						let peer_state = per_peer_state.get(&counterparty_node_id).unwrap().lock().unwrap();
+						peer_state.latest_features.clone()
+					};
+					let (shutdown_msg, monitor_update, failed_htlcs) = chan_entry.get_mut().get_shutdown(&self.keys_manager, &their_features)?;
 					channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
-						node_id: chan_entry.get().get_counterparty_node_id(),
+						node_id: counterparty_node_id,
 						msg: shutdown_msg
 					});
 					if let Some(monitor_update) = monitor_update {