bark/vtxo/
signing.rs

1
2use bitcoin::secp256k1::schnorr;
3use bitcoin::{taproot, TapSighash, Witness};
4use bitcoin::key::Keypair;
5use log::error;
6
7use ark::VtxoPolicy;
8use ark::vtxo::{TapScriptClause, Vtxo, VtxoClause};
9use ark::vtxo::policy::signing::VtxoSigner;
10
11use crate::{SECP, Wallet};
12
13impl Wallet {
14	pub (crate) async fn clause_keypair(&self, clause: &VtxoClause) -> Option<Keypair> {
15		let clause_pubkey = clause.pubkey();
16		self.pubkey_keypair(&clause_pubkey).await.ok()
17			.flatten().map(|(_, keypair)| keypair)
18	}
19}
20
21#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
22#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
23impl VtxoSigner for Wallet {
24	async fn sign_keyspend<G: Sync + Send>(
25		&self,
26		vtxo: &Vtxo<G, VtxoPolicy>,
27		_sighash: TapSighash,
28	) -> Option<schnorr::Signature> {
29		error!(
30			"CODE BUG: wallet was asked to sign a keyspend clause but that should never happen \
31				(VTXO ID: {}; policy type: {})", vtxo.id(), vtxo.policy_type(),
32		);
33		None
34	}
35
36	async fn witness(
37		&self,
38		clause: &VtxoClause,
39		control_block: &taproot::ControlBlock,
40		sighash: TapSighash,
41	) -> Option<Witness> {
42		let signature = match self.clause_keypair(clause).await {
43			Some(keypair) => {
44				SECP.sign_schnorr_with_aux_rand(&sighash.into(), &keypair, &rand::random())
45			},
46			None => return None,
47		};
48
49		match clause {
50			VtxoClause::DelayedSign(c) => Some(c.witness(&signature, control_block)),
51			VtxoClause::DelayedTimelockSign(c) => Some(c.witness(&signature, &control_block)),
52			VtxoClause::TimelockSign(c) => Some(c.witness(&signature, &control_block)),
53			VtxoClause::HashDelaySign(c) => {
54				let receive = self.db.fetch_lightning_receive_by_payment_hash(c.hash.into())
55					.await.ok().flatten();
56
57				receive.map(|r| c.witness(
58					&(signature, r.payment_preimage.to_byte_array()), &control_block,
59				))
60			},
61			VtxoClause::HashSign(_) => None, // Not used by bark
62		}
63	}
64}
bark/vtxo/signing.rs

bark/vtxo/
signing.rs
