From: Antoine Riard <ariard@student.42.fr>
Date: Wed, 31 Oct 2018 02:49:19 +0000 (+0000)
Subject: Track local_commitment_tx at funding_created
X-Git-Tag: v0.0.12~271^2~11
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=8c638ffc812e1c51bafcb4b92260336574d8fcb2;p=rust-lightning

Track local_commitment_tx at funding_created

Goal to claim sizeable push_msat and in event of
local commitment tx being broadcast without htlcs
---

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 207eda418..9b8db2fe3 100644
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -1371,22 +1371,25 @@ impl Channel {
 		Ok(())
 	}
 
-	fn funding_created_signature(&mut self, sig: &Signature) -> Result<(Transaction, Signature), HandleError> {
+	fn funding_created_signature(&mut self, sig: &Signature) -> Result<(Transaction, Transaction, Signature, TxCreationKeys), HandleError> {
 		let funding_script = self.get_funding_redeemscript();
 
 		let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?;
-		let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
+		let mut local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0;
 		let local_sighash = Message::from_slice(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap();
 
-		// They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish.
+		// They sign the "local" commitment transaction...
 		secp_call!(self.secp_ctx.verify(&local_sighash, &sig, &self.their_funding_pubkey.unwrap()), "Invalid funding_created signature from peer", self.channel_id());
 
+		// ...and we sign it, allowing us to broadcast the tx if we wish
+		self.sign_commitment_transaction(&mut local_initial_commitment_tx, sig);
+
 		let remote_keys = self.build_remote_transaction_keys()?;
 		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0;
 		let remote_sighash = Message::from_slice(&bip143::SighashComponents::new(&remote_initial_commitment_tx).sighash_all(&remote_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap();
 
 		// We sign the "remote" commitment transaction, allowing them to broadcast the tx if they wish.
-		Ok((remote_initial_commitment_tx, self.secp_ctx.sign(&remote_sighash, &self.local_keys.funding_key)))
+		Ok((remote_initial_commitment_tx, local_initial_commitment_tx, self.secp_ctx.sign(&remote_sighash, &self.local_keys.funding_key), local_keys))
 	}
 
 	pub fn funding_created(&mut self, msg: &msgs::FundingCreated) -> Result<(msgs::FundingSigned, ChannelMonitor), HandleError> {
@@ -1409,7 +1412,7 @@ impl Channel {
 		let funding_txo_script = self.get_funding_redeemscript().to_v0_p2wsh();
 		self.channel_monitor.set_funding_info((funding_txo, funding_txo_script));
 
-		let (remote_initial_commitment_tx, our_signature) = match self.funding_created_signature(&msg.signature) {
+		let (remote_initial_commitment_tx, local_initial_commitment_tx, our_signature, local_keys) = match self.funding_created_signature(&msg.signature) {
 			Ok(res) => res,
 			Err(e) => {
 				self.channel_monitor.unset_funding_info();
@@ -1420,6 +1423,8 @@ impl Channel {
 		// Now that we're past error-generating stuff, update our local state:
 
 		self.channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number);
+		self.last_local_commitment_txn = vec![local_initial_commitment_tx.clone()];
+		self.channel_monitor.provide_latest_local_commitment_tx_info(local_initial_commitment_tx, local_keys, self.feerate_per_kw, Vec::new());
 		self.channel_state = ChannelState::FundingSent as u32;
 		self.channel_id = funding_txo.to_channel_id();
 		self.cur_remote_commitment_transaction_number -= 1;