use crate::util::byte_utils;
use crate::util::events::Event;
#[cfg(anchors)]
-use crate::util::events::{AnchorDescriptor, BumpTransactionEvent};
+use crate::util::events::{AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
use crate::prelude::*;
use core::{cmp, mem};
/// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
/// transaction.
resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
+ resolving_tx: Option<Transaction>,
/// Only set if the HTLC claim was ours using a payment preimage
payment_preimage: Option<PaymentPreimage>,
}
(0, mapped_commitment_tx_output_idx, required),
(1, self.resolving_txid, option),
(2, self.payment_preimage, option),
+ (3, self.resolving_tx, option),
});
Ok(())
}
let mut mapped_commitment_tx_output_idx = 0;
let mut resolving_txid = None;
let mut payment_preimage = None;
+ let mut resolving_tx = None;
read_tlv_fields!(reader, {
(0, mapped_commitment_tx_output_idx, required),
(1, resolving_txid, option),
(2, payment_preimage, option),
+ (3, resolving_tx, option),
});
Ok(Self {
commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
resolving_txid,
payment_preimage,
+ resolving_tx,
})
}
}
if let Some(v) = htlc.transaction_output_index { v } else { return None; };
let mut htlc_spend_txid_opt = None;
+ let mut htlc_spend_tx_opt = None;
let mut holder_timeout_spend_pending = None;
let mut htlc_spend_pending = None;
let mut holder_delayed_output_pending = None;
OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
debug_assert!(htlc_spend_txid_opt.is_none());
- htlc_spend_txid_opt = event.transaction.as_ref().map(|tx| tx.txid());
+ htlc_spend_txid_opt = Some(&event.txid);
+ debug_assert!(htlc_spend_tx_opt.is_none());
+ htlc_spend_tx_opt = event.transaction.as_ref();
debug_assert!(holder_timeout_spend_pending.is_none());
debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
holder_timeout_spend_pending = Some(event.confirmation_threshold());
OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
debug_assert!(htlc_spend_txid_opt.is_none());
- htlc_spend_txid_opt = event.transaction.as_ref().map(|tx| tx.txid());
+ htlc_spend_txid_opt = Some(&event.txid);
+ debug_assert!(htlc_spend_tx_opt.is_none());
+ htlc_spend_tx_opt = event.transaction.as_ref();
debug_assert!(htlc_spend_pending.is_none());
htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
},
let htlc_resolved = self.htlcs_resolved_on_chain.iter()
.find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
debug_assert!(htlc_spend_txid_opt.is_none());
- htlc_spend_txid_opt = v.resolving_txid;
+ htlc_spend_txid_opt = v.resolving_txid.as_ref();
+ debug_assert!(htlc_spend_tx_opt.is_none());
+ htlc_spend_tx_opt = v.resolving_tx.as_ref();
true
} else { false });
debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
+ let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
let htlc_output_to_spend =
if let Some(txid) = htlc_spend_txid_opt {
- debug_assert!(
- self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_none(),
- "This code needs updating for anchors");
- BitcoinOutPoint::new(txid, 0)
+ // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
+ // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
+ // locate the correct output by ensuring its adjacent input spends the HTLC output
+ // in the commitment.
+ if let Some(ref tx) = htlc_spend_tx_opt {
+ let htlc_input_idx_opt = tx.input.iter().enumerate()
+ .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
+ .map(|(idx, _)| idx as u32);
+ debug_assert!(htlc_input_idx_opt.is_some());
+ BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
+ } else {
+ debug_assert!(!self.onchain_tx_handler.opt_anchors());
+ BitcoinOutPoint::new(*txid, 0)
+ }
} else {
- BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx)
+ htlc_commitment_outpoint
};
let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
} = &event.event {
if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
- Some(tx.txid()) == htlc_spend_txid_opt ||
- inp.previous_output.txid == htlc_spend_txid
+ tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
} else {
Some(inp.previous_output.txid) == confirmed_txid &&
inp.previous_output.vout == htlc_commitment_tx_output_idx
log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
self.lockdown_from_offchain = true;
if *should_broadcast {
+ // There's no need to broadcast our commitment transaction if we've seen one
+ // confirmed (even with 1 confirmation) as it'll be rejected as
+ // duplicate/conflicting.
+ let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
+ self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
+ OnchainEvent::FundingSpendConfirmation { .. } => true,
+ _ => false,
+ }).is_some();
+ if detected_funding_spend {
+ continue;
+ }
self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
// If the channel supports anchor outputs, we'll need to emit an external
// event to be consumed such that a child transaction is broadcast with a
pending_htlcs,
}));
},
+ ClaimEvent::BumpHTLC {
+ target_feerate_sat_per_1000_weight, htlcs,
+ } => {
+ let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
+ for htlc in htlcs {
+ htlc_descriptors.push(HTLCDescriptor {
+ channel_keys_id: self.channel_keys_id,
+ channel_value_satoshis: self.channel_value_satoshis,
+ channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
+ commitment_txid: htlc.commitment_txid,
+ per_commitment_number: htlc.per_commitment_number,
+ htlc: htlc.htlc,
+ preimage: htlc.preimage,
+ counterparty_sig: htlc.counterparty_sig,
+ });
+ }
+ ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
+ target_feerate_sat_per_1000_weight,
+ htlc_descriptors,
+ }));
+ }
}
}
ret
}
/// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
- fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
- let htlc_txid = tx.txid();
- if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
- return (Vec::new(), None)
- }
-
- macro_rules! ignore_error {
- ( $thing : expr ) => {
- match $thing {
- Ok(a) => a,
- Err(_) => return (Vec::new(), None)
- }
- };
- }
-
+ fn check_spend_counterparty_htlc<L: Deref>(
+ &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
+ ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
- let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
+ let per_commitment_key = match SecretKey::from_slice(&secret) {
+ Ok(key) => key,
+ Err(_) => return (Vec::new(), None)
+ };
let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
- log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, 0);
- let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, tx.output[0].value, self.counterparty_commitment_params.on_counterparty_tx_csv);
- let justice_package = PackageTemplate::build_package(htlc_txid, 0, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
- let claimable_outpoints = vec!(justice_package);
- let outputs = vec![(0, tx.output[0].clone())];
- (claimable_outpoints, Some((htlc_txid, outputs)))
+ let htlc_txid = tx.txid();
+ let mut claimable_outpoints = vec![];
+ let mut outputs_to_watch = None;
+ // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
+ // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
+ // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
+ // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
+ // confirmed revoked HTLC transaction (for more details, see
+ // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
+ //
+ // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
+ // and claim those which spend the commitment transaction, have a witness of 5 elements, and
+ // have a corresponding output at the same index within the transaction.
+ for (idx, input) in tx.input.iter().enumerate() {
+ if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
+ log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
+ let revk_outp = RevokedOutput::build(
+ per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
+ self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
+ tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv
+ );
+ let justice_package = PackageTemplate::build_package(
+ htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
+ height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height
+ );
+ claimable_outpoints.push(justice_package);
+ if outputs_to_watch.is_none() {
+ outputs_to_watch = Some((htlc_txid, vec![]));
+ }
+ outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
+ }
+ }
+ (claimable_outpoints, outputs_to_watch)
}
// Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
if let Some(transaction_output_index) = htlc.transaction_output_index {
- let htlc_output = if htlc.offered {
- HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
+ let (htlc_output, aggregable) = if htlc.offered {
+ let htlc_output = HolderHTLCOutput::build_offered(
+ htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
+ );
+ (htlc_output, false)
+ } else {
+ let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
+ preimage.clone()
} else {
- let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
- preimage.clone()
- } else {
- // We can't build an HTLC-Success transaction without the preimage
- continue;
- };
- HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
+ // We can't build an HTLC-Success transaction without the preimage
+ continue;
};
- let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
+ let htlc_output = HolderHTLCOutput::build_accepted(
+ payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
+ );
+ (htlc_output, self.onchain_tx_handler.opt_anchors())
+ };
+ let htlc_package = PackageTemplate::build_package(
+ holder_tx.txid, transaction_output_index,
+ PackageSolvingData::HolderHTLCOutput(htlc_output),
+ htlc.cltv_expiry, aggregable, conf_height
+ );
claim_requests.push(htlc_package);
}
}
if tx.input.len() == 1 {
// Assuming our keys were not leaked (in which case we're screwed no matter what),
- // commitment transactions and HTLC transactions will all only ever have one input,
- // which is an easy way to filter out any potential non-matching txn for lazy
- // filters.
+ // commitment transactions and HTLC transactions will all only ever have one input
+ // (except for HTLC transactions for channels with anchor outputs), which is an easy
+ // way to filter out any potential non-matching txn for lazy filters.
let prevout = &tx.input[0].previous_output;
if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
let mut balance_spendable_csv = None;
commitment_tx_to_counterparty_output,
},
});
- } else {
- if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
- let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
+ }
+ }
+ if tx.input.len() >= 1 {
+ // While all commitment transactions have one input, HTLC transactions may have more
+ // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
+ // other ways which can have more than one output.
+ for tx_input in &tx.input {
+ let commitment_txid = tx_input.previous_output.txid;
+ if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
+ let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
+ &tx, commitment_number, &commitment_txid, height, &logger
+ );
claimable_outpoints.append(&mut new_outpoints);
if let Some(new_outputs) = new_outputs_option {
watch_outputs.push(new_outputs);
}
+ // Since there may be multiple HTLCs for this channel (all spending the
+ // same commitment tx) being claimed by the counterparty within the same
+ // transaction, and `check_spend_counterparty_htlc` already checks all the
+ // ones relevant to this channel, we can safely break from our loop.
+ break;
}
}
- }
- // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
- // can also be resolved in a few other ways which can have more than one output. Thus,
- // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
- self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
+ self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
- self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
+ self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
+ }
}
if height > self.best_block.height() {
htlc_value_satoshis,
}));
self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
- commitment_tx_output_idx, resolving_txid: Some(entry.txid),
+ commitment_tx_output_idx,
+ resolving_txid: Some(entry.txid),
+ resolving_tx: entry.transaction,
payment_preimage: None,
});
},
},
OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
- commitment_tx_output_idx: Some(commitment_tx_output_idx), resolving_txid: Some(entry.txid),
+ commitment_tx_output_idx: Some(commitment_tx_output_idx),
+ resolving_txid: Some(entry.txid),
+ resolving_tx: entry.transaction,
payment_preimage: preimage,
});
},
projects / rust-lightning / blobdiff