X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fonchaintx.rs;h=5aba6593834cf3a37848fe1c9763e6b5f6de7f3a;hb=d795e247b76f6b0d70a2529c2a05995a909b1134;hp=f690d3664273b94e8ee9fe8d6d4c9f16d44ece0e;hpb=23e233ba257c27b14d0d6167f1d87d9c1bf5e344;p=rust-lightning diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index f690d366..5aba6593 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -12,31 +12,25 @@ //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all //! building, tracking, bumping and notifications functions. -#[cfg(anchors)] use bitcoin::PackedLockTime; use bitcoin::blockdata::transaction::Transaction; use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint; use bitcoin::blockdata::script::Script; - +use bitcoin::hashes::{Hash, HashEngine}; +use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::hash_types::{Txid, BlockHash}; - use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature}; use bitcoin::secp256k1; -use crate::chain::keysinterface::{ChannelSigner, EntropySource, SignerProvider}; +use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight; +use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, WriteableEcdsaChannelSigner}; use crate::ln::msgs::DecodeError; use crate::ln::PaymentPreimage; -#[cfg(anchors)] -use crate::ln::chan_utils::{self, HTLCOutputInCommitment}; -use crate::ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction}; -#[cfg(anchors)] -use crate::chain::chaininterface::ConfirmationTarget; -use crate::chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator}; +use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction}; +use crate::chain::ClaimId; +use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator}; use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER}; -use crate::chain::keysinterface::WriteableEcdsaChannelSigner; -#[cfg(anchors)] -use crate::chain::package::PackageSolvingData; -use crate::chain::package::PackageTemplate; +use crate::chain::package::{PackageSolvingData, PackageTemplate}; use crate::util::logger::Logger; use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter}; @@ -46,9 +40,8 @@ use alloc::collections::BTreeMap; use core::cmp; use core::ops::Deref; use core::mem::replace; -#[cfg(anchors)] use core::mem::swap; -use bitcoin::hashes::Hash; +use crate::ln::features::ChannelTypeFeatures; const MAX_ALLOC_SIZE: usize = 64*1024; @@ -56,7 +49,7 @@ const MAX_ALLOC_SIZE: usize = 64*1024; /// transaction causing it. /// /// Used to determine when the on-chain event can be considered safe from a chain reorganization. -#[derive(PartialEq, Eq)] +#[derive(Clone, PartialEq, Eq)] struct OnchainEventEntry { txid: Txid, height: u32, @@ -76,14 +69,14 @@ impl OnchainEventEntry { /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly. -#[derive(PartialEq, Eq)] +#[derive(Clone, PartialEq, Eq)] enum OnchainEvent { /// A pending request has been claimed by a transaction spending the exact same set of outpoints /// as the request. This claim can either be ours or from the counterparty. Once the claiming /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the /// pending request. Claim { - package_id: PackageID, + claim_id: ClaimId, }, /// The counterparty has claimed an outpoint from one of our pending requests through a /// different transaction than ours. If our transaction was attempting to claim multiple @@ -126,7 +119,7 @@ impl MaybeReadable for OnchainEventEntry { impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, (0, Claim) => { - (0, package_id, required), + (0, claim_id, required), }, (1, ContentiousOutpoint) => { (0, package, required), @@ -177,8 +170,8 @@ impl Writeable for Option>> { } } -#[cfg(anchors)] /// The claim commonly referred to as the pre-signed second-stage HTLC transaction. +#[derive(Clone, PartialEq, Eq)] pub(crate) struct ExternalHTLCClaim { pub(crate) commitment_txid: Txid, pub(crate) per_commitment_number: u64, @@ -189,7 +182,7 @@ pub(crate) struct ExternalHTLCClaim { // Represents the different types of claims for which events are yielded externally to satisfy said // claims. -#[cfg(anchors)] +#[derive(Clone, PartialEq, Eq)] pub(crate) enum ClaimEvent { /// Event yielded to signal that the commitment transaction fee must be bumped to claim any /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist. @@ -212,26 +205,20 @@ pub(crate) enum ClaimEvent { pub(crate) enum OnchainClaim { /// A finalized transaction pending confirmation spending the output to claim. Tx(Transaction), - #[cfg(anchors)] /// An event yielded externally to signal additional inputs must be added to a transaction /// pending confirmation spending the output to claim. Event(ClaimEvent), } -/// An internal identifier to track pending package claims within the `OnchainTxHandler`. -type PackageID = [u8; 32]; - /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and /// do RBF bumping if possible. +#[derive(Clone)] pub struct OnchainTxHandler { + channel_value_satoshis: u64, + channel_keys_id: [u8; 32], destination_script: Script, 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. - holder_htlc_sigs: Option>>, prev_holder_commitment: Option, - prev_holder_htlc_sigs: Option>>, pub(super) signer: ChannelSigner, pub(crate) channel_transaction_parameters: ChannelTransactionParameters, @@ -248,13 +235,13 @@ pub struct OnchainTxHandler { // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved. // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial) #[cfg(test)] // Used in functional_test to verify sanitization - pub(crate) pending_claim_requests: HashMap, + pub(crate) pending_claim_requests: HashMap, #[cfg(not(test))] - pending_claim_requests: HashMap, + pending_claim_requests: HashMap, // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec` // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence - // of a `PackageID`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and + // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and // a new block has been connected, resulting in a new claim, the previous will be replaced with // the new. // @@ -262,8 +249,7 @@ pub struct OnchainTxHandler { // - A channel has been force closed by broadcasting the holder's latest commitment transaction // - A block being connected/disconnected // - Learning the preimage for an HTLC we can claim onchain - #[cfg(anchors)] - pending_claim_events: Vec<(PackageID, ClaimEvent)>, + pending_claim_events: Vec<(ClaimId, ClaimEvent)>, // Used to link outpoints claimed in a connected block to a pending claim request. The keys // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to @@ -272,9 +258,9 @@ pub struct OnchainTxHandler { // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if // the block gets disconnected. #[cfg(test)] // Used in functional_test to verify sanitization - pub claimable_outpoints: HashMap, + pub claimable_outpoints: HashMap, #[cfg(not(test))] - claimable_outpoints: HashMap, + claimable_outpoints: HashMap, locktimed_packages: BTreeMap>, @@ -286,11 +272,11 @@ pub struct OnchainTxHandler { impl PartialEq for OnchainTxHandler { fn eq(&self, other: &Self) -> bool { // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose. - self.destination_script == other.destination_script && + self.channel_value_satoshis == other.channel_value_satoshis && + self.channel_keys_id == other.channel_keys_id && + self.destination_script == other.destination_script && self.holder_commitment == other.holder_commitment && - self.holder_htlc_sigs == other.holder_htlc_sigs && self.prev_holder_commitment == other.prev_holder_commitment && - self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs && self.channel_transaction_parameters == other.channel_transaction_parameters && self.pending_claim_requests == other.pending_claim_requests && self.claimable_outpoints == other.claimable_outpoints && @@ -308,9 +294,9 @@ impl OnchainTxHandler self.destination_script.write(writer)?; self.holder_commitment.write(writer)?; - self.holder_htlc_sigs.write(writer)?; + None::>>>.write(writer)?; // holder_htlc_sigs self.prev_holder_commitment.write(writer)?; - self.prev_holder_htlc_sigs.write(writer)?; + None::>>>.write(writer)?; // prev_holder_htlc_sigs self.channel_transaction_parameters.write(writer)?; @@ -365,9 +351,9 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP let destination_script = Readable::read(reader)?; let holder_commitment = Readable::read(reader)?; - let holder_htlc_sigs = Readable::read(reader)?; + let _holder_htlc_sigs: Option>> = Readable::read(reader)?; let prev_holder_commitment = Readable::read(reader)?; - let prev_holder_htlc_sigs = Readable::read(reader)?; + let _prev_holder_htlc_sigs: Option>> = Readable::read(reader)?; let channel_parameters = Readable::read(reader)?; @@ -428,18 +414,17 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); Ok(OnchainTxHandler { + channel_value_satoshis, + channel_keys_id, destination_script, holder_commitment, - holder_htlc_sigs, prev_holder_commitment, - prev_holder_htlc_sigs, signer, channel_transaction_parameters: channel_parameters, claimable_outpoints, locktimed_packages, pending_claim_requests, onchain_events_awaiting_threshold_conf, - #[cfg(anchors)] pending_claim_events: Vec::new(), secp_ctx, }) @@ -447,20 +432,23 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP } impl OnchainTxHandler { - pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1) -> Self { + pub(crate) fn new( + channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: Script, + signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, + holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1 + ) -> Self { OnchainTxHandler { + channel_value_satoshis, + channel_keys_id, destination_script, holder_commitment, - holder_htlc_sigs: None, prev_holder_commitment: None, - prev_holder_htlc_sigs: None, signer, channel_transaction_parameters: channel_parameters, pending_claim_requests: HashMap::new(), claimable_outpoints: HashMap::new(), locktimed_packages: BTreeMap::new(), onchain_events_awaiting_threshold_conf: Vec::new(), - #[cfg(anchors)] pending_claim_events: Vec::new(), secp_ctx, } @@ -474,11 +462,62 @@ impl OnchainTxHandler self.holder_commitment.to_broadcaster_value_sat() } - #[cfg(anchors)] - pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec { + pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> { let mut events = Vec::new(); swap(&mut events, &mut self.pending_claim_events); - events.into_iter().map(|(_, event)| event).collect() + events + } + + /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is + /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool + /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend + /// invoking this every 30 seconds, or lower if running in an environment with spotty + /// connections, like on mobile. + pub(crate) fn rebroadcast_pending_claims( + &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator, + logger: &L, + ) + where + B::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + { + let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len()); + for (claim_id, request) in self.pending_claim_requests.iter() { + let inputs = request.outpoints(); + log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs); + bump_requests.push((*claim_id, request.clone())); + } + for (claim_id, request) in bump_requests { + self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger) + .map(|(_, new_feerate, claim)| { + let mut bumped_feerate = false; + if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) { + bumped_feerate = request.previous_feerate() > new_feerate; + mut_request.set_feerate(new_feerate); + } + match claim { + OnchainClaim::Tx(tx) => { + let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" }; + log_info!(logger, "{} onchain {}", log_start, log_tx!(tx)); + broadcaster.broadcast_transactions(&[&tx]); + }, + OnchainClaim::Event(event) => { + let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" }; + log_info!(logger, "{} onchain event to spend inputs {:?}", log_start, + request.outpoints()); + #[cfg(debug_assertions)] { + debug_assert!(request.requires_external_funding()); + let num_existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == claim_id).count(); + assert!(num_existing == 0 || num_existing == 1); + } + self.pending_claim_events.retain(|event| event.0 != claim_id); + self.pending_claim_events.push((claim_id, event)); + } + } + }); + } } /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty @@ -489,9 +528,13 @@ impl OnchainTxHandler /// /// 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(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) -> Option<(Option, u64, OnchainClaim)> - where F::Target: FeeEstimator, - L::Target: Logger, + fn generate_claim( + &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool, + fee_estimator: &LowerBoundedFeeEstimator, logger: &L, + ) -> Option<(u32, u64, OnchainClaim)> + where + F::Target: FeeEstimator, + L::Target: Logger, { let request_outpoints = cached_request.outpoints(); if request_outpoints.is_empty() { @@ -507,12 +550,12 @@ impl OnchainTxHandler // transaction is reorged out. let mut all_inputs_have_confirmed_spend = true; for outpoint in request_outpoints.iter() { - if let Some((request_package_id, _)) = self.claimable_outpoints.get(*outpoint) { + if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) { // We check for outpoint spends within claims individually rather than as a set // since requests can have outpoints split off. if !self.onchain_events_awaiting_threshold_conf.iter() - .any(|event_entry| if let OnchainEvent::Claim { package_id } = event_entry.event { - *request_package_id == package_id + .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event { + *request_claim_id == claim_id } else { // The onchain event is not a claim, keep seeking until we find one. false @@ -533,39 +576,38 @@ impl OnchainTxHandler // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it). - let new_timer = Some(cached_request.get_height_timer(cur_height)); + let new_timer = cached_request.get_height_timer(cur_height); if cached_request.is_malleable() { - #[cfg(anchors)] - { // Attributes are not allowed on if expressions on our current MSRV of 1.41. - if cached_request.requires_external_funding() { - let target_feerate_sat_per_1000_weight = cached_request - .compute_package_feerate(fee_estimator, ConfirmationTarget::HighPriority); - if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) { - return Some(( - new_timer, - target_feerate_sat_per_1000_weight as u64, - OnchainClaim::Event(ClaimEvent::BumpHTLC { - target_feerate_sat_per_1000_weight, - htlcs, - tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)), - }), - )); - } else { - return None; - } + if cached_request.requires_external_funding() { + let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate( + fee_estimator, ConfirmationTarget::OnChainSweep, force_feerate_bump + ); + if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) { + return Some(( + new_timer, + target_feerate_sat_per_1000_weight as u64, + OnchainClaim::Event(ClaimEvent::BumpHTLC { + target_feerate_sat_per_1000_weight, + htlcs, + tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)), + }), + )); + } else { + return None; } } let predicted_weight = cached_request.package_weight(&self.destination_script); if let Some((output_value, new_feerate)) = cached_request.compute_package_output( - predicted_weight, self.destination_script.dust_value().to_sat(), fee_estimator, logger, + predicted_weight, self.destination_script.dust_value().to_sat(), + force_feerate_bump, fee_estimator, logger, ) { assert!(new_feerate != 0); let transaction = cached_request.finalize_malleable_package( cur_height, self, output_value, self.destination_script.clone(), logger ).unwrap(); - log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate); + log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate); assert!(predicted_weight >= transaction.weight()); return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction))); } @@ -573,9 +615,6 @@ impl OnchainTxHandler // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some // packages may support fee bumping through Child-Pays-For-Parent, indicated by those // which require external funding. - #[cfg(not(anchors))] - let inputs = cached_request.inputs(); - #[cfg(anchors)] let mut inputs = cached_request.inputs(); debug_assert_eq!(inputs.len(), 1); let tx = match cached_request.finalize_untractable_package(self, logger) { @@ -583,15 +622,30 @@ impl OnchainTxHandler None => return None, }; if !cached_request.requires_external_funding() { - return Some((None, 0, OnchainClaim::Tx(tx))); + return Some((new_timer, 0, OnchainClaim::Tx(tx))); } - #[cfg(anchors)] return inputs.find_map(|input| match input { // Commitment inputs with anchors support are the only untractable inputs supported // thus far that require external funding. - PackageSolvingData::HolderFundingOutput(..) => { + PackageSolvingData::HolderFundingOutput(output) => { debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(), "Holder commitment transaction mismatch"); + + let conf_target = ConfirmationTarget::OnChainSweep; + let package_target_feerate_sat_per_1000_weight = cached_request + .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump); + if let Some(input_amount_sat) = output.funding_amount { + let fee_sat = input_amount_sat - tx.output.iter().map(|output| output.value).sum::(); + let commitment_tx_feerate_sat_per_1000_weight = + compute_feerate_sat_per_1000_weight(fee_sat, tx.weight() as u64); + if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight { + log_debug!(logger, "Pre-signed {} already has feerate {} sat/kW above required {} sat/kW", + log_tx!(tx), commitment_tx_feerate_sat_per_1000_weight, + package_target_feerate_sat_per_1000_weight); + return Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))); + } + } + // We'll locate an anchor output we can spend within the commitment transaction. let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey; match chan_utils::get_anchor_output(&tx, funding_pubkey) { @@ -599,9 +653,6 @@ impl OnchainTxHandler Some((idx, _)) => { // TODO: Use a lower confirmation target when both our and the // counterparty's latest commitment don't have any HTLCs present. - let conf_target = ConfirmationTarget::HighPriority; - let package_target_feerate_sat_per_1000_weight = cached_request - .compute_package_feerate(fee_estimator, conf_target); Some(( new_timer, package_target_feerate_sat_per_1000_weight as u64, @@ -616,7 +667,7 @@ impl OnchainTxHandler // attempt to broadcast the transaction with its current fee rate and hope // it confirms. This is essentially the same behavior as a commitment // transaction without anchor outputs. - None => Some((None, 0, OnchainClaim::Tx(tx.clone()))), + None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))), } }, _ => { @@ -689,8 +740,8 @@ impl OnchainTxHandler preprocessed_requests.push(req); } - // Claim everything up to and including cur_height + 1 - let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 2)); + // Claim everything up to and including `cur_height` + let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1)); for (pop_height, mut entry) in self.locktimed_packages.iter_mut() { log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height); preprocessed_requests.append(&mut entry); @@ -700,42 +751,52 @@ impl OnchainTxHandler // Generate claim transactions and track them to bump if necessary at // height timer expiration (i.e in how many blocks we're going to take action). for mut req in preprocessed_requests { - if let Some((new_timer, new_feerate, claim)) = self.generate_claim(cur_height, &req, &*fee_estimator, &*logger) { + if let Some((new_timer, new_feerate, claim)) = self.generate_claim( + cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger, + ) { req.set_timer(new_timer); req.set_feerate(new_feerate); - let package_id = match claim { + // Once a pending claim has an id assigned, it remains fixed until the claim is + // satisfied, regardless of whether the claim switches between different variants of + // `OnchainClaim`. + let claim_id = match claim { OnchainClaim::Tx(tx) => { log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); - broadcaster.broadcast_transaction(&tx); - tx.txid().into_inner() + broadcaster.broadcast_transactions(&[&tx]); + ClaimId(tx.txid().into_inner()) }, - #[cfg(anchors)] OnchainClaim::Event(claim_event) => { log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints()); - let package_id = match claim_event { - ClaimEvent::BumpCommitment { ref commitment_tx, .. } => commitment_tx.txid().into_inner(), + let claim_id = match claim_event { + ClaimEvent::BumpCommitment { ref commitment_tx, .. } => + // For commitment claims, we can just use their txid as it should + // already be unique. + ClaimId(commitment_tx.txid().into_inner()), ClaimEvent::BumpHTLC { ref htlcs, .. } => { - // Use the same construction as a lightning channel id to generate - // the package id for this request based on the first HTLC. It - // doesn't matter what we use as long as it's unique per request. - let mut package_id = [0; 32]; - package_id[..].copy_from_slice(&htlcs[0].commitment_txid[..]); - let htlc_output_index = htlcs[0].htlc.transaction_output_index.unwrap(); - package_id[30] ^= ((htlc_output_index >> 8) & 0xff) as u8; - package_id[31] ^= ((htlc_output_index >> 0) & 0xff) as u8; - package_id + // For HTLC claims, commit to the entire set of HTLC outputs to + // claim, which will always be unique per request. Once a claim ID + // is generated, it is assigned and remains unchanged, even if the + // underlying set of HTLCs changes. + let mut engine = Sha256::engine(); + for htlc in htlcs { + engine.input(&htlc.commitment_txid.into_inner()); + engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes()); + } + ClaimId(Sha256::from_engine(engine).into_inner()) }, }; - debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == package_id).count(), 0); - self.pending_claim_events.push((package_id, claim_event)); - package_id + debug_assert!(self.pending_claim_requests.get(&claim_id).is_none()); + debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0); + self.pending_claim_events.push((claim_id, claim_event)); + claim_id }, }; + debug_assert!(self.pending_claim_requests.get(&claim_id).is_none()); for k in req.outpoints() { log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout); - self.claimable_outpoints.insert(k.clone(), (package_id, conf_height)); + self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height)); } - self.pending_claim_requests.insert(package_id, req); + self.pending_claim_requests.insert(claim_id, req); } } } @@ -762,9 +823,9 @@ impl OnchainTxHandler // Scan all input to verify is one of the outpoint spent is of interest for us let mut claimed_outputs_material = Vec::new(); for inp in &tx.input { - if let Some((package_id, _)) = self.claimable_outpoints.get(&inp.previous_output) { + if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) { // If outpoint has claim request pending on it... - if let Some(request) = self.pending_claim_requests.get_mut(package_id) { + if let Some(request) = self.pending_claim_requests.get_mut(claim_id) { //... we need to verify equality between transaction outpoints and claim request // outpoints to know if transaction is the original claim or a bumped one issued // by us. @@ -784,7 +845,7 @@ impl OnchainTxHandler txid: tx.txid(), height: conf_height, block_hash: Some(conf_hash), - event: OnchainEvent::Claim { package_id: *package_id } + event: OnchainEvent::Claim { claim_id: *claim_id } }; if !self.onchain_events_awaiting_threshold_conf.contains(&entry) { self.onchain_events_awaiting_threshold_conf.push(entry); @@ -811,21 +872,19 @@ impl OnchainTxHandler } //TODO: recompute soonest_timelock to avoid wasting a bit on fees if at_least_one_drop { - bump_candidates.insert(*package_id, request.clone()); + bump_candidates.insert(*claim_id, request.clone()); // If we have any pending claim events for the request being updated // that have yet to be consumed, we'll remove them since they will // end up producing an invalid transaction by double spending // input(s) that already have a confirmed spend. If such spend is // reorged out of the chain, then we'll attempt to re-spend the // inputs once we see it. - #[cfg(anchors)] { - #[cfg(debug_assertions)] { - let existing = self.pending_claim_events.iter() - .filter(|entry| entry.0 == *package_id).count(); - assert!(existing == 0 || existing == 1); - } - self.pending_claim_events.retain(|entry| entry.0 != *package_id); + #[cfg(debug_assertions)] { + let existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == *claim_id).count(); + assert!(existing == 0 || existing == 1); } + self.pending_claim_events.retain(|entry| entry.0 != *claim_id); } } break; //No need to iterate further, either tx is our or their @@ -853,23 +912,21 @@ impl OnchainTxHandler for entry in onchain_events_awaiting_threshold_conf { if entry.has_reached_confirmation_threshold(cur_height) { match entry.event { - OnchainEvent::Claim { package_id } => { + OnchainEvent::Claim { claim_id } => { // We may remove a whole set of claim outpoints here, as these one may have // been aggregated in a single tx and claimed so atomically - if let Some(request) = self.pending_claim_requests.remove(&package_id) { + if let Some(request) = self.pending_claim_requests.remove(&claim_id) { for outpoint in request.outpoints() { log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.", - outpoint, log_bytes!(package_id)); + outpoint, log_bytes!(claim_id.0)); self.claimable_outpoints.remove(outpoint); } - #[cfg(anchors)] { - #[cfg(debug_assertions)] { - let num_existing = self.pending_claim_events.iter() - .filter(|entry| entry.0 == package_id).count(); - assert!(num_existing == 0 || num_existing == 1); - } - self.pending_claim_events.retain(|(id, _)| *id != package_id); + #[cfg(debug_assertions)] { + let num_existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == claim_id).count(); + assert!(num_existing == 0 || num_existing == 1); } + self.pending_claim_events.retain(|(id, _)| *id != claim_id); } }, OnchainEvent::ContentiousOutpoint { package } => { @@ -884,36 +941,35 @@ impl OnchainTxHandler } // Check if any pending claim request must be rescheduled - for (package_id, request) in self.pending_claim_requests.iter() { - if let Some(h) = request.timer() { - if cur_height >= h { - bump_candidates.insert(*package_id, request.clone()); - } + for (claim_id, request) in self.pending_claim_requests.iter() { + if cur_height >= request.timer() { + bump_candidates.insert(*claim_id, request.clone()); } } // Build, bump and rebroadcast tx accordingly log_trace!(logger, "Bumping {} candidates", bump_candidates.len()); - for (package_id, request) in bump_candidates.iter() { - if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(cur_height, &request, &*fee_estimator, &*logger) { + for (claim_id, request) in bump_candidates.iter() { + if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim( + cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger, + ) { match bump_claim { OnchainClaim::Tx(bump_tx) => { log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx)); - broadcaster.broadcast_transaction(&bump_tx); + broadcaster.broadcast_transactions(&[&bump_tx]); }, - #[cfg(anchors)] OnchainClaim::Event(claim_event) => { log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints()); #[cfg(debug_assertions)] { let num_existing = self.pending_claim_events.iter(). - filter(|entry| entry.0 == *package_id).count(); + filter(|entry| entry.0 == *claim_id).count(); assert!(num_existing == 0 || num_existing == 1); } - self.pending_claim_events.retain(|event| event.0 != *package_id); - self.pending_claim_events.push((*package_id, claim_event)); + self.pending_claim_events.retain(|event| event.0 != *claim_id); + self.pending_claim_events.push((*claim_id, claim_event)); }, } - if let Some(request) = self.pending_claim_requests.get_mut(package_id) { + if let Some(request) = self.pending_claim_requests.get_mut(claim_id) { request.set_timer(new_timer); request.set_feerate(new_feerate); } @@ -974,25 +1030,28 @@ impl OnchainTxHandler self.onchain_events_awaiting_threshold_conf.push(entry); } } - for ((_package_id, _), ref mut request) in bump_candidates.iter_mut() { - if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(height, &request, fee_estimator, &&*logger) { + for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() { + // `height` is the height being disconnected, so our `current_height` is 1 lower. + let current_height = height - 1; + if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim( + current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger + ) { request.set_timer(new_timer); request.set_feerate(new_feerate); match bump_claim { OnchainClaim::Tx(bump_tx) => { log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx)); - broadcaster.broadcast_transaction(&bump_tx); + broadcaster.broadcast_transactions(&[&bump_tx]); }, - #[cfg(anchors)] OnchainClaim::Event(claim_event) => { log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints()); #[cfg(debug_assertions)] { let num_existing = self.pending_claim_events.iter() - .filter(|entry| entry.0 == *_package_id).count(); + .filter(|entry| entry.0 == *_claim_id).count(); assert!(num_existing == 0 || num_existing == 1); } - self.pending_claim_events.retain(|event| event.0 != *_package_id); - self.pending_claim_events.push((*_package_id, claim_event)); + self.pending_claim_events.retain(|event| event.0 != *_claim_id); + self.pending_claim_events.push((*_claim_id, claim_event)); }, } } @@ -1029,91 +1088,67 @@ impl OnchainTxHandler pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) { 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 self.holder_htlc_sigs.is_none() { - let (_sig, sigs) = self.signer.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 self.prev_holder_htlc_sigs.is_none() { - if let Some(ref holder_commitment) = self.prev_holder_commitment { - let (_sig, sigs) = self.signer.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)); - } - } - } - - fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec) -> Vec> { - let mut ret = Vec::new(); - for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() { - let tx_idx = htlc.transaction_output_index.unwrap(); - if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); } - ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone())); - } - ret + pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction { + &self.holder_commitment.trust().built_transaction().transaction } //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may - // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created, + // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after OutboundV1Channel::get_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) -> Transaction { - let (sig, htlc_sigs) = self.signer.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)); + let sig = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment"); 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) -> Transaction { - let (sig, htlc_sigs) = self.signer.unsafe_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)); + let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment"); self.holder_commitment.add_holder_sig(funding_redeemscript, sig) } pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option) -> Option { - let mut htlc_tx = None; - 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 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(); - if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs { - let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap(); - let holder_commitment = self.prev_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 get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| { + let trusted_tx = holder_commitment.trust(); + if trusted_tx.txid() != outp.txid { + return None; } - } - htlc_tx + let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate() + .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout) + .unwrap(); + let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx]; + let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx( + &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage, + ); + + let htlc_descriptor = HTLCDescriptor { + channel_derivation_parameters: ChannelDerivationParameters { + value_satoshis: self.channel_value_satoshis, + keys_id: self.channel_keys_id, + transaction_parameters: self.channel_transaction_parameters.clone(), + }, + commitment_txid: trusted_tx.txid(), + per_commitment_number: trusted_tx.commitment_number(), + per_commitment_point: trusted_tx.per_commitment_point(), + feerate_per_kw: trusted_tx.feerate_per_kw(), + htlc: htlc.clone(), + preimage: preimage.clone(), + counterparty_sig: counterparty_htlc_sig.clone(), + }; + let htlc_sig = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx).unwrap(); + htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness( + htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage, + ); + Some(htlc_tx) + }; + + // Check if the HTLC spends from the current holder commitment first, or the previous. + get_signed_htlc_tx(&self.holder_commitment) + .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment))) } - #[cfg(anchors)] pub(crate) fn generate_external_htlc_claim( &self, outp: &::bitcoin::OutPoint, preimage: &Option ) -> Option { @@ -1144,21 +1179,7 @@ impl OnchainTxHandler .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten()) } - pub(crate) fn opt_anchors(&self) -> bool { - self.channel_transaction_parameters.opt_anchors.is_some() - } - - #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] - pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option) -> Option { - let latest_had_sigs = self.holder_htlc_sigs.is_some(); - let prev_had_sigs = self.prev_holder_htlc_sigs.is_some(); - let ret = self.get_fully_signed_htlc_tx(outp, preimage); - if !latest_had_sigs { - self.holder_htlc_sigs = None; - } - if !prev_had_sigs { - self.prev_holder_htlc_sigs = None; - } - ret + pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures { + &self.channel_transaction_parameters.channel_type_features } }