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feat(actor): remove txhandler clone by refactoring sighash calc
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Added a new scriptkind parser for code quality with tests
Implemented sighash calculation closure to avoid cloning and ensure immutability of the TxHandler inputs.
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@mmtftr
mmtftr committed Feb 7, 2025
1 parent dff0664 commit 45a16fb
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Showing 4 changed files with 291 additions and 134 deletions.
210 changes: 102 additions & 108 deletions core/src/actor.rs
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Original file line number Diff line number Diff line change
@@ -1,7 +1,4 @@
use crate::builder::script::{
CheckSig, DepositScript, OtherSpendable, PreimageRevealScript, SpendPath, TimelockScript,
WinternitzCommit,
};
use crate::builder::script::SpendPath;
use crate::builder::transaction::input::SpentTxIn;
use crate::builder::transaction::TxHandler;
use crate::errors::BridgeError;
Expand All @@ -12,7 +9,7 @@ use crate::rpc::clementine::TaggedSignature;
use crate::utils::{self, SECP};
use bitcoin::hashes::hash160;
use bitcoin::secp256k1::PublicKey;
use bitcoin::sighash::{self, SighashCache};
use bitcoin::sighash::SighashCache;
use bitcoin::taproot::{LeafVersion, TaprootSpendInfo};
use bitcoin::{
hashes::Hash,
Expand All @@ -23,8 +20,6 @@ use bitcoin::{TapNodeHash, TapSighashType, TxOut, Witness};
use bitvm::signatures::winternitz::{
self, BinarysearchVerifier, StraightforwardConverter, Winternitz,
};
use clap::ValueHint::Other;
use secp256k1::schnorr::Signature;

/// Available transaction types for [`WinternitzDerivationPath`].
#[derive(Clone, Copy, Debug)]
Expand Down Expand Up @@ -302,7 +297,7 @@ impl Actor {

fn get_saved_signature(
signature_id: SignatureId,
signatures: &Vec<TaggedSignature>,
signatures: &[TaggedSignature],
) -> Option<schnorr::Signature> {
signatures
.iter()
Expand All @@ -327,99 +322,108 @@ impl Actor {
Ok(())
}

//
pub fn partial_sign_winternitz_or_preimagereveal(
&self,
txhandler: &mut TxHandler,
signatures: &Vec<TaggedSignature>,
signatures: &[TaggedSignature],
data: &Vec<u8>,
) -> Result<(), BridgeError> {
let txhandlerclone = txhandler.clone();
let signer = |idx: usize, spt: &SpentTxIn| -> Result<Option<Witness>, BridgeError> {
let spendinfo = spt
.get_spendable()
.get_spend_info()
.as_ref()
.ok_or_else(|| BridgeError::MissingSpendInfo)?;
match spt.get_spend_path() {
SpendPath::ScriptSpend(script_idx) => {
let script = spt
.get_spendable()
.get_scripts()
.get(script_idx)
.ok_or_else(|| BridgeError::NoScriptAtIndex(script_idx))?;
let mut witness = Witness::default();

if let Some(script) = script.as_any().downcast_ref::<OtherSpendable>() {
return Ok(None);
} else if let Some(script) = script.as_any().downcast_ref::<DepositScript>() {
return Ok(None);
} else if let Some(script) =
script.as_any().downcast_ref::<PreimageRevealScript>()
{
if (script.0 != self.xonly_public_key) {
return Err(BridgeError::NotOwnedScriptPath);
}
witness = script.generate_script_inputs(
data,
&self.sign_taproot_script_spend_tx(&txhandlerclone, idx, script_idx)?,
);
} else if let Some(script) = script.as_any().downcast_ref::<TimelockScript>() {
return Ok(None);
} else if let Some(script) = script.as_any().downcast_ref::<WinternitzCommit>()
{
if (script.2 != self.xonly_public_key) {
return Err(BridgeError::NotOwnedScriptPath);
let mut signed_winternitz = false;

let signer =
move |_: usize,
spt: &SpentTxIn,
calc_sighash: Box<dyn FnOnce() -> Result<TapSighash, BridgeError> + '_>|
-> Result<Option<Witness>, BridgeError> {
let spendinfo = spt
.get_spendable()
.get_spend_info()
.as_ref()
.ok_or_else(|| BridgeError::MissingSpendInfo)?;
match spt.get_spend_path() {
SpendPath::ScriptSpend(script_idx) => {
let script = spt
.get_spendable()
.get_scripts()
.get(script_idx)
.ok_or_else(|| BridgeError::NoScriptAtIndex(script_idx))?;

use crate::builder::script::ScriptKind as Kind;

let mut witness = match script.into() {
Kind::PreimageRevealScript(script) => {
if script.0 != self.xonly_public_key {
return Err(BridgeError::NotOwnedScriptPath);
}
script.generate_script_inputs(data, &self.sign(calc_sighash()?))
}
Kind::WinternitzCommit(script) => {
if script.2 != self.xonly_public_key {
return Err(BridgeError::NotOwnedScriptPath);
}
script.generate_script_inputs(
data,
&self
.winternitz_secret_key
.ok_or(BridgeError::NoWinternitzSecretKey)?
.as_ref()
.to_vec(),
&self.sign(calc_sighash()?),
)
}
Kind::CheckSig(_)
| Kind::Other(_)
| Kind::DepositScript(_)
| Kind::TimelockScript(_) => return Ok(None),
};

if signed_winternitz {
return Err(BridgeError::MultipleWinternitzScripts);
}
witness = script.generate_script_inputs(
data,
&self
.winternitz_secret_key
.ok_or(BridgeError::NoWinternitzSecretKey)?
.as_ref()
.to_vec(),
&self.sign_taproot_script_spend_tx(&txhandlerclone, idx, script_idx)?,
);
} else if let Some(script) = script.as_any().downcast_ref::<CheckSig>() {
return Ok(None);
} else {
return Err(BridgeError::Error("Not handled script type".to_string()));

signed_winternitz = true;

Self::add_script_path_to_witness(
&mut witness,
&script.to_script_buf(),
spendinfo,
)?;
Ok(Some(witness))
}
Self::add_script_path_to_witness(
&mut witness,
&script.to_script_buf(),
&spendinfo,
)?;
return Ok(Some(witness));
}
SpendPath::KeySpend => {
let xonly_public_key = spendinfo.internal_key();
if xonly_public_key == self.xonly_public_key {
let sighash = txhandlerclone
.calculate_pubkey_spend_sighash(idx, Some(TapSighashType::All))?;
// TODO: get Schnorr sigs, not Vec<TaggedSignature>, pref in HashMap
let sig = Self::get_saved_signature(spt.get_signature_id(), &signatures);
let sig = match sig {
Some(sig) => sig,
None => self.sign_with_tweak(sighash, spendinfo.merkle_root())?,
};
return Ok(Some(Witness::from_slice(&[&sig.serialize()])));
SpendPath::KeySpend => {
let xonly_public_key = spendinfo.internal_key();
if xonly_public_key == self.xonly_public_key {
let sighash = calc_sighash()?;
// TODO: get Schnorr sigs, not Vec<TaggedSignature>, pref in HashMap
let sig = Self::get_saved_signature(spt.get_signature_id(), signatures);
let sig = match sig {
Some(sig) => sig,
None => self.sign_with_tweak(sighash, spendinfo.merkle_root())?,
};
return Ok(Some(Witness::from_slice(&[&sig.serialize()])));
}
Err(NotOwnKeyPath)
}
Err(NotOwnKeyPath)
SpendPath::Unknown => Err(BridgeError::SpendPathNotSpecified),
}
SpendPath::Unknown => Err(BridgeError::SpendPathNotSpecified),
}
};
};

txhandler.sign_txins(signer)?;
Ok(())
}

pub fn partial_sign(
&self,
txhandler: &mut TxHandler,
signatures: &Vec<TaggedSignature>,
signatures: &[TaggedSignature],
) -> Result<(), BridgeError> {
let txhandlerclone = txhandler.clone();
let signer = |idx: usize, spt: &SpentTxIn| -> Result<Option<Witness>, BridgeError> {
let signer = move |_,
spt: &SpentTxIn,
calc_sighash: Box<
dyn for<'a> FnOnce() -> Result<TapSighash, BridgeError> + '_,
>|
-> Result<Option<Witness>, BridgeError> {
let spendinfo = spt
.get_spendable()
.get_spend_info()
Expand All @@ -433,43 +437,32 @@ impl Actor {
.get_scripts()
.get(script_idx)
.ok_or_else(|| BridgeError::NoScriptAtIndex(script_idx))?;
let sig = Self::get_saved_signature(spt.get_signature_id(), &signatures);
let sig = Self::get_saved_signature(spt.get_signature_id(), signatures);
use crate::builder::script::ScriptKind as Kind;

// Set the script inputs of the witness
let mut witness: Witness = match script.into() {
Kind::DepositScript(script) => {
match (sig, script.0 == self.xonly_public_key) {
(Some(sig), _) => script.generate_script_inputs(&sig),
(None, true) => script.generate_script_inputs(
&self.sign_taproot_script_spend_tx(
&txhandlerclone,
idx,
script_idx,
)?,
),
(None, true) => {
script.generate_script_inputs(&self.sign(calc_sighash()?))
}
(None, false) => return Err(BridgeError::SignatureNotFound),
}
}
Kind::TimelockScript(script) => match (sig, script.0) {
(Some(sig), Some(_)) => script.generate_script_inputs(&Some(sig)),
(None, Some(xonly_key)) if xonly_key == self.xonly_public_key => script
.generate_script_inputs(&Some(self.sign_taproot_script_spend_tx(
&txhandlerclone,
idx,
script_idx,
)?)),
(None, Some(xonly_key)) if xonly_key == self.xonly_public_key => {
script.generate_script_inputs(&Some(self.sign(calc_sighash()?)))
}
(None, Some(_)) => return Err(BridgeError::SignatureNotFound),
(_, None) => Witness::new(),
},
Kind::CheckSig(script) => match (sig, script.0 == self.xonly_public_key) {
(Some(sig), _) => script.generate_script_inputs(&sig),
(None, true) => {
script.generate_script_inputs(&self.sign_taproot_script_spend_tx(
&txhandlerclone,
idx,
script_idx,
)?)
script.generate_script_inputs(&self.sign(calc_sighash()?))
}
(None, false) => return Err(BridgeError::SignatureNotFound),
},
Expand All @@ -482,18 +475,17 @@ impl Actor {
Self::add_script_path_to_witness(
&mut witness,
&script.to_script_buf(),
&spendinfo,
spendinfo,
)?;
return Ok(Some(witness));
Ok(Some(witness))
}
SpendPath::KeySpend => {
let xonly_public_key = spendinfo.internal_key();

if xonly_public_key == self.xonly_public_key {
let sighash = txhandlerclone
.calculate_pubkey_spend_sighash(idx, Some(TapSighashType::All))?;
let sighash = calc_sighash()?;
// TODO: get Schnorr sigs, not Vec<TaggedSignature>, pref in HashMap
let sig = Self::get_saved_signature(spt.get_signature_id(), &signatures);
let sig = Self::get_saved_signature(spt.get_signature_id(), signatures);
let sig = match sig {
Some(sig) => sig,
None => self.sign_with_tweak(sighash, spendinfo.merkle_root())?,
Expand All @@ -505,6 +497,7 @@ impl Actor {
SpendPath::Unknown => Err(BridgeError::SpendPathNotSpecified),
}
};

txhandler.sign_txins(signer)?;
Ok(())
}
Expand All @@ -515,6 +508,7 @@ mod tests {
use super::Actor;
use crate::builder::address::create_taproot_address;

use crate::builder::script::ScriptKind as Kind;
use crate::builder::transaction::input::SpendableTxIn;
use crate::builder::transaction::output::UnspentTxOut;
use crate::builder::transaction::TxHandlerBuilder;
Expand Down
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