use std::collections::{HashMap, hash_map};
use std::cmp;
use std::ops::Deref;
+use std::mem::replace;
const MAX_ALLOC_SIZE: usize = 64*1024;
/// do RBF bumping if possible.
pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
destination_script: Script,
- holder_commitment: Option<HolderCommitmentTransaction>,
+ holder_commitment: HolderCommitmentTransaction,
// holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
// transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
// the set of HTLCs in the HolderCommitmentTransaction.
}
impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
- pub(crate) fn new(destination_script: Script, keys: ChanSigner, channel_parameters: ChannelTransactionParameters) -> Self {
+ pub(crate) fn new(destination_script: Script, keys: ChanSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction) -> Self {
let key_storage = keys;
OnchainTxHandler {
destination_script,
- holder_commitment: None,
+ holder_commitment,
holder_htlc_sigs: None,
prev_holder_commitment: None,
prev_holder_htlc_sigs: None,
/// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
/// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
+ /// Panics if there are signing errors, because signing operations in reaction to on-chain events
+ /// are not expected to fail, and if they do, we may lose funds.
fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u32, Transaction)>
where F::Target: FeeEstimator,
L::Target: Logger,
chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, *on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key)
};
- if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx) {
- bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
- bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
- if htlc.is_some() {
- bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
- } else {
- bumped_tx.input[i].witness.push(vec!(1));
- }
- bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
- } else { return None; }
- //TODO: panic ?
+ let sig = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx).expect("sign justice tx");
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ if htlc.is_some() {
+ bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
+ } else {
+ bumped_tx.input[i].witness.push(vec!(1));
+ }
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_holder" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
}
let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
- if let Ok(sig) = self.key_storage.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx) {
- bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
- bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
- if let &Some(preimage) = preimage {
- bumped_tx.input[i].witness.push(preimage.0.to_vec());
- } else {
- // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
- bumped_tx.input[i].witness.push(vec![]);
- }
- bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
+ let sig = self.key_storage.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx).expect("sign counterparty HTLC tx");
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ if let &Some(preimage) = preimage {
+ bumped_tx.input[i].witness.push(preimage.0.to_vec());
+ } else {
+ // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
+ bumped_tx.input[i].witness.push(vec![]);
}
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
log_trace!(logger, "Going to broadcast Claim Transaction {} claiming counterparty {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
}
},
return None;
},
&InputMaterial::Funding { ref funding_redeemscript } => {
- let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript).unwrap();
+ let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
// Timer set to $NEVER given we can't bump tx without anchor outputs
log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
- return Some((None, self.holder_commitment.as_ref().unwrap().feerate_per_kw(), signed_tx));
+ return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
}
_ => unreachable!()
}
}
pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
- self.prev_holder_commitment = self.holder_commitment.take();
- self.holder_commitment = Some(tx);
+ self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
+ self.holder_htlc_sigs = None;
}
+ // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
+ // in some configurations, the holder commitment tx has been signed and broadcast by a
+ // ChannelMonitor replica, so we handle that case here.
fn sign_latest_holder_htlcs(&mut self) {
- if let Some(ref holder_commitment) = self.holder_commitment {
- if let Ok(sigs) = self.key_storage.sign_holder_commitment_htlc_transactions(holder_commitment, &self.secp_ctx) {
- self.holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
- }
+ if self.holder_htlc_sigs.is_none() {
+ let (_sig, sigs) = self.key_storage.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
}
}
+ // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
+ // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
+ // broadcast the previous one before we sync with it. We handle that case here.
fn sign_prev_holder_htlcs(&mut self) {
- if let Some(ref holder_commitment) = self.prev_holder_commitment {
- if let Ok(sigs) = self.key_storage.sign_holder_commitment_htlc_transactions(holder_commitment, &self.secp_ctx) {
+ if self.prev_holder_htlc_sigs.is_none() {
+ if let Some(ref holder_commitment) = self.prev_holder_commitment {
+ let (_sig, sigs) = self.key_storage.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
}
}
// have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
// before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
// to monitor before.
- pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
- if let Some(ref mut holder_commitment) = self.holder_commitment {
- match self.key_storage.sign_holder_commitment(&holder_commitment, &self.secp_ctx) {
- Ok(sig) => {
- Some(holder_commitment.add_holder_sig(funding_redeemscript, sig))
- },
- Err(_) => return None,
- }
- } else {
- None
- }
+ pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
+ let (sig, htlc_sigs) = self.key_storage.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
+ self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
}
#[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
- pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
- if let Some(ref mut holder_commitment) = self.holder_commitment {
- match self.key_storage.sign_holder_commitment(holder_commitment, &self.secp_ctx) {
- Ok(sig) => {
- Some(holder_commitment.add_holder_sig(funding_redeemscript, sig))
- },
- Err(_) => return None,
- }
- } else {
- None
- }
+ pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
+ let (sig, htlc_sigs) = self.key_storage.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
+ self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
}
pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
let mut htlc_tx = None;
- if self.holder_commitment.is_some() {
- let commitment_txid = self.holder_commitment.as_ref().unwrap().trust().txid();
- if commitment_txid == outp.txid {
- self.sign_latest_holder_htlcs();
- if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
- let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
- let holder_commitment = self.holder_commitment.as_ref().unwrap();
- let trusted_tx = holder_commitment.trust();
- let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
- htlc_tx = Some(trusted_tx
- .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
- }
+ let commitment_txid = self.holder_commitment.trust().txid();
+ // Check if the HTLC spends from the current holder commitment
+ if commitment_txid == outp.txid {
+ self.sign_latest_holder_htlcs();
+ if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
+ let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
+ let trusted_tx = self.holder_commitment.trust();
+ let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
+ htlc_tx = Some(trusted_tx
+ .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
}
}
- if self.prev_holder_commitment.is_some() {
+ // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
+ if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
if commitment_txid == outp.txid {
self.sign_prev_holder_htlcs();
projects / rust-lightning / blobdiff