Merge pull request #1748 from valentinewallace/2022-10-custom-oms

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

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index 69ca4fb83f954f946b1236c7239980c3de104b85..15bc0d0e23e08079751972f32d751a76dc4706d7 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -526,8 +526,8 @@ pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u1
        res
 }
 
-#[derive(Clone, PartialEq, Eq)]
 /// Information about an HTLC as it appears in a commitment transaction
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct HTLCOutputInCommitment {
        /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
        /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
@@ -727,6 +727,23 @@ pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script {
                .into_script()
 }
 
+#[cfg(anchors)]
+/// Locates the output with an anchor script paying to `funding_pubkey` within `commitment_tx`.
+pub(crate) fn get_anchor_output<'a>(commitment_tx: &'a Transaction, funding_pubkey: &PublicKey) -> Option<(u32, &'a TxOut)> {
+       let anchor_script = chan_utils::get_anchor_redeemscript(funding_pubkey).to_v0_p2wsh();
+       commitment_tx.output.iter().enumerate()
+               .find(|(_, txout)| txout.script_pubkey == anchor_script)
+               .map(|(idx, txout)| (idx as u32, txout))
+}
+
+/// Returns the witness required to satisfy and spend an anchor input.
+pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness {
+       let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key);
+       let mut funding_sig = funding_sig.serialize_der().to_vec();
+       funding_sig.push(EcdsaSighashType::All as u8);
+       Witness::from_vec(vec![funding_sig, anchor_redeem_script.to_bytes()])
+}
+
 /// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
 /// The fields are organized by holder/counterparty.
 ///