use crate::bitcoin::wallet::Watchable; use crate::bitcoin::{self, Address, PunishTimelock, Transaction, TxCancel, Txid}; use ::bitcoin::util::bip143::SigHashCache; use ::bitcoin::{SigHash, SigHashType}; use anyhow::{Context, Result}; use bdk::bitcoin::Script; use miniscript::{Descriptor, DescriptorTrait}; use std::collections::HashMap; #[derive(Debug)] pub struct TxPunish { inner: Transaction, digest: SigHash, cancel_output_descriptor: Descriptor<::bitcoin::PublicKey>, watch_script: Script, } impl TxPunish { pub fn new( tx_cancel: &TxCancel, punish_address: &Address, punish_timelock: PunishTimelock, ) -> Self { let tx_punish = tx_cancel.build_spend_transaction(punish_address, Some(punish_timelock)); let digest = SigHashCache::new(&tx_punish).signature_hash( 0, // Only one input: cancel transaction &tx_cancel.output_descriptor.script_code(), tx_cancel.amount().as_sat(), SigHashType::All, ); Self { inner: tx_punish, digest, cancel_output_descriptor: tx_cancel.output_descriptor.clone(), watch_script: punish_address.script_pubkey(), } } pub fn digest(&self) -> SigHash { self.digest } pub fn complete( self, tx_punish_sig_bob: bitcoin::Signature, a: bitcoin::SecretKey, B: bitcoin::PublicKey, ) -> Result { let sig_a = a.sign(self.digest()); let sig_b = tx_punish_sig_bob; let satisfier = { let mut satisfier = HashMap::with_capacity(2); let A = a.public().into(); let B = B.into(); // The order in which these are inserted doesn't matter satisfier.insert(A, (sig_a.into(), ::bitcoin::SigHashType::All)); satisfier.insert(B, (sig_b.into(), ::bitcoin::SigHashType::All)); satisfier }; let mut tx_punish = self.inner; self.cancel_output_descriptor .satisfy(&mut tx_punish.input[0], satisfier) .context("Failed to satisfy inputs with given signatures")?; Ok(tx_punish) } } impl Watchable for TxPunish { fn id(&self) -> Txid { self.inner.txid() } fn script(&self) -> Script { self.watch_script.clone() } }