use crate::chain::chaininterface::BroadcasterInterface;
use crate::chain::ClaimId;
use crate::io_extras::sink;
+use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
use crate::ln::chan_utils;
use crate::ln::chan_utils::{
ANCHOR_INPUT_WITNESS_WEIGHT, HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT,
}
impl AnchorDescriptor {
+ /// Returns the UTXO to be spent by the anchor input, which can be obtained via
+ /// [`Self::unsigned_tx_input`].
+ pub fn previous_utxo(&self) -> TxOut {
+ TxOut {
+ script_pubkey: self.witness_script().to_v0_p2wsh(),
+ value: ANCHOR_OUTPUT_VALUE_SATOSHI,
+ }
+ }
+
+ /// Returns the unsigned transaction input spending the anchor output in the commitment
+ /// transaction.
+ pub fn unsigned_tx_input(&self) -> TxIn {
+ TxIn {
+ previous_output: self.outpoint.clone(),
+ script_sig: Script::new(),
+ sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
+ witness: Witness::new(),
+ }
+ }
+
+ /// Returns the witness script of the anchor output in the commitment transaction.
+ pub fn witness_script(&self) -> Script {
+ let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
+ chan_utils::get_anchor_redeemscript(&channel_params.broadcaster_pubkeys().funding_pubkey)
+ }
+
+ /// Returns the fully signed witness required to spend the anchor output in the commitment
+ /// transaction.
+ pub fn tx_input_witness(&self, signature: &Signature) -> Witness {
+ let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
+ chan_utils::build_anchor_input_witness(&channel_params.broadcaster_pubkeys().funding_pubkey, signature)
+ }
+
/// Derives the channel signer required to sign the anchor input.
pub fn derive_channel_signer<SP: Deref>(&self, signer_provider: &SP) -> <SP::Target as SignerProvider>::Signer
where
}
impl HTLCDescriptor {
+ /// Returns the UTXO to be spent by the HTLC input, which can be obtained via
+ /// [`Self::unsigned_tx_input`].
+ pub fn previous_utxo<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
+ TxOut {
+ script_pubkey: self.witness_script(secp).to_v0_p2wsh(),
+ value: self.htlc.amount_msat / 1000,
+ }
+ }
+
/// Returns the unsigned transaction input spending the HTLC output in the commitment
/// transaction.
pub fn unsigned_tx_input(&self) -> TxIn {
pub struct Input {
/// The unique identifier of the input.
pub outpoint: OutPoint,
+ /// The UTXO being spent by the input.
+ pub previous_utxo: TxOut,
/// The upper-bound weight consumed by the input's full [`TxIn::script_sig`] and
/// [`TxIn::witness`], each with their lengths included, required to satisfy the output's
/// script.
) -> Result<Transaction, ()> {
let must_spend = vec![Input {
outpoint: anchor_descriptor.outpoint,
+ previous_utxo: anchor_descriptor.previous_utxo(),
satisfaction_weight: commitment_tx.weight() as u64 + ANCHOR_INPUT_WITNESS_WEIGHT + EMPTY_SCRIPT_SIG_WEIGHT,
}];
let coin_selection = self.utxo_source.select_confirmed_utxos(
let mut tx = Transaction {
version: 2,
lock_time: PackedLockTime::ZERO, // TODO: Use next best height.
- input: vec![TxIn {
- previous_output: anchor_descriptor.outpoint,
- script_sig: Script::new(),
- sequence: Sequence::ZERO,
- witness: Witness::new(),
- }],
+ input: vec![anchor_descriptor.unsigned_tx_input()],
output: vec![],
};
self.process_coin_selection(&mut tx, coin_selection);
self.utxo_source.sign_tx(&mut anchor_tx)?;
let signer = anchor_descriptor.derive_channel_signer(&self.signer_provider);
let anchor_sig = signer.sign_holder_anchor_input(&anchor_tx, 0, &self.secp)?;
- anchor_tx.input[0].witness =
- chan_utils::build_anchor_input_witness(&signer.pubkeys().funding_pubkey, &anchor_sig);
+ anchor_tx.input[0].witness = anchor_descriptor.tx_input_witness(&anchor_sig);
self.broadcaster.broadcast_transactions(&[&commitment_tx, &anchor_tx]);
Ok(())
let htlc_input = htlc_descriptor.unsigned_tx_input();
must_spend.push(Input {
outpoint: htlc_input.previous_output.clone(),
+ previous_utxo: htlc_descriptor.previous_utxo(&self.secp),
satisfaction_weight: EMPTY_SCRIPT_SIG_WEIGHT + if htlc_descriptor.preimage.is_some() {
HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT
} else {