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Antoine Riard
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Build witness_script for justice tx inside OnchainTxHandler
By moving script generation inside OnchainTxHandler, we may dry-up further ChannelMonitor in next commits.
1 parent 6d8b85c commit dbb0bbf

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2 files changed

+43
-38
lines changed

2 files changed

+43
-38
lines changed

‎lightning/src/ln/channelmonitor.rs

Lines changed: 9 additions & 26 deletions
Original file line numberDiff line numberDiff line change
@@ -424,8 +424,7 @@ struct LocalSignedTx {
424424
#[derive(Clone, PartialEq)]
425425
pub(crate) enum InputMaterial {
426426
Revoked {
427-
witness_script: Script,
428-
pubkey: Option<PublicKey>,
427+
per_commitment_point: PublicKey,
429428
key: SecretKey,
430429
input_descriptor: InputDescriptors,
431430
amount: u64,
@@ -449,10 +448,9 @@ pub(crate) enum InputMaterial {
449448
impl Writeable for InputMaterial {
450449
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
451450
match self {
452-
&InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref input_descriptor, ref amount} => {
451+
&InputMaterial::Revoked { ref per_commitment_point, ref key, ref input_descriptor, ref amount} => {
453452
writer.write_all(&[0; 1])?;
454-
witness_script.write(writer)?;
455-
pubkey.write(writer)?;
453+
per_commitment_point.write(writer)?;
456454
writer.write_all(&key[..])?;
457455
input_descriptor.write(writer)?;
458456
writer.write_all(&byte_utils::be64_to_array(*amount))?;
@@ -483,14 +481,12 @@ impl Readable for InputMaterial {
483481
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
484482
let input_material = match <u8 as Readable>::read(reader)? {
485483
0 => {
486-
let witness_script = Readable::read(reader)?;
487-
let pubkey = Readable::read(reader)?;
484+
let per_commitment_point = Readable::read(reader)?;
488485
let key = Readable::read(reader)?;
489486
let input_descriptor = Readable::read(reader)?;
490487
let amount = Readable::read(reader)?;
491488
InputMaterial::Revoked {
492-
witness_script,
493-
pubkey,
489+
per_commitment_point,
494490
key,
495491
input_descriptor,
496492
amount
@@ -1450,13 +1446,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
14501446
let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
14511447
let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
14521448
let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
1453-
let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().htlc_basepoint));
14541449
let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.payment_base_key()));
14551450
let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
1456-
let a_htlc_key = match self.their_htlc_base_key {
1457-
None => return (claimable_outpoints, (commitment_txid, watch_outputs)),
1458-
Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
1459-
};
14601451

14611452
let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
14621453
let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
@@ -1471,7 +1462,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
14711462
// First, process non-htlc outputs (to_local & to_remote)
14721463
for (idx, outp) in tx.output.iter().enumerate() {
14731464
if outp.script_pubkey == revokeable_p2wsh {
1474-
let witness_data = InputMaterial::Revoked { witness_script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value };
1465+
let witness_data = InputMaterial::Revoked { per_commitment_point, key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value };
14751466
claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
14761467
}
14771468
}
@@ -1480,13 +1471,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
14801471
if let Some(ref per_commitment_data) = per_commitment_option {
14811472
for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
14821473
if let Some(transaction_output_index) = htlc.transaction_output_index {
1483-
let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
14841474
if transaction_output_index as usize >= tx.output.len() ||
1485-
tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1486-
tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1475+
tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
14871476
return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
14881477
}
1489-
let witness_data = InputMaterial::Revoked { witness_script: expected_script, pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value };
1478+
let witness_data = InputMaterial::Revoked { per_commitment_point, key: revocation_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value };
14901479
claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
14911480
}
14921481
}
@@ -1662,16 +1651,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
16621651
let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
16631652
let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
16641653
let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1665-
let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
16661654
let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
1667-
let delayed_key = match self.their_delayed_payment_base_key {
1668-
None => return (Vec::new(), None),
1669-
Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1670-
};
1671-
let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
16721655

16731656
log_trace!(self, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1674-
let witness_data = InputMaterial::Revoked { witness_script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value };
1657+
let witness_data = InputMaterial::Revoked { per_commitment_point, key: revocation_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value };
16751658
let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
16761659
(claimable_outpoints, Some((htlc_txid, tx.output.clone())))
16771660
}

‎lightning/src/ln/onchaintx.rs

Lines changed: 34 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -665,19 +665,41 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
665665

666666
for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
667667
match per_outp_material {
668-
&InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref input_descriptor, ref amount } => {
669-
let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
670-
let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
671-
let sig = self.secp_ctx.sign(&sighash, &key);
672-
bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
673-
bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
674-
if *input_descriptor != InputDescriptors::RevokedOutput {
675-
bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
676-
} else {
677-
bumped_tx.input[i].witness.push(vec!(1));
668+
&InputMaterial::Revoked { ref per_commitment_point, ref key, ref input_descriptor, ref amount } => {
669+
if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, &self.justice_tx_cache.remote_delayed_payment_base_key, &self.justice_tx_cache.remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().payment_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
670+
671+
let mut this_htlc = None;
672+
if *input_descriptor != InputDescriptors::RevokedOutput {
673+
if let Some(htlcs) = self.justice_tx_cache.per_htlc.get(&outp.txid) {
674+
for htlc in htlcs {
675+
if htlc.transaction_output_index.unwrap() == outp.vout {
676+
this_htlc = Some(htlc);
677+
}
678+
}
679+
}
680+
}
681+
682+
let witness_script = if *input_descriptor != InputDescriptors::RevokedOutput && this_htlc.is_some() {
683+
chan_utils::get_htlc_redeemscript_with_explicit_keys(&this_htlc.unwrap(), &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key)
684+
} else if *input_descriptor != InputDescriptors::RevokedOutput {
685+
return None;
686+
} else {
687+
chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, self.remote_csv, &chan_keys.a_delayed_payment_key)
688+
};
689+
690+
let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
691+
let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
692+
let sig = self.secp_ctx.sign(&sighash, &key);
693+
bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
694+
bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
695+
if *input_descriptor != InputDescriptors::RevokedOutput {
696+
bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
697+
} else {
698+
bumped_tx.input[i].witness.push(vec!(1));
699+
}
700+
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
701+
log_trace!(self, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_local" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
678702
}
679-
bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
680-
log_trace!(self, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_local" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
681703
},
682704
&InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
683705
if !preimage.is_some() { bumped_tx.lock_time = *locktime }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation

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