Set transaction locktime on malleable packages to discourage fee sniping

[rust-lightning] / lightning / src / chain / package.rs

diff --git a/lightning/src/chain/package.rs b/lightning/src/chain/package.rs
index 2ab37484148e48402674c68a8b2503961dcebe12..e8886e5a2aa49958fcac012529a3ae4160348230 100644 (file)
--- a/lightning/src/chain/package.rs
+++ b/lightning/src/chain/package.rs
@@ -434,7 +434,6 @@ impl PackageSolvingData {
                                let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
                                let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 
-                               bumped_tx.lock_time = PackedLockTime(outp.htlc.cltv_expiry); // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
                                if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
                                        let mut ser_sig = sig.serialize_der().to_vec();
                                        ser_sig.push(EcdsaSighashType::All as u8);
@@ -708,12 +707,13 @@ impl PackageTemplate {
                htlcs
        }
        pub(crate) fn finalize_malleable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
-               &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L
+               &self, current_height: u32, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64,
+               destination_script: Script, logger: &L
        ) -> Option<Transaction> where L::Target: Logger {
                debug_assert!(self.is_malleable());
                let mut bumped_tx = Transaction {
                        version: 2,
-                       lock_time: PackedLockTime::ZERO,
+                       lock_time: PackedLockTime(self.package_locktime(current_height)),
                        input: vec![],
                        output: vec![TxOut {
                                script_pubkey: destination_script,