1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see ManyChannelMonitor for more.
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{TxOut,Transaction};
25 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
26 use bitcoin::blockdata::script::{Script, Builder};
27 use bitcoin::blockdata::opcodes;
28 use bitcoin::consensus::encode;
30 use bitcoin::hashes::Hash;
31 use bitcoin::hashes::sha256::Hash as Sha256;
32 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
34 use bitcoin::secp256k1::{Secp256k1,Signature};
35 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
36 use bitcoin::secp256k1;
38 use ln::msgs::DecodeError;
40 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HolderCommitmentTransaction, HTLCType};
41 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
42 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
44 use chain::chaininterface::{ChainListener, ChainWatchedUtil, BroadcasterInterface, FeeEstimator};
45 use chain::transaction::OutPoint;
46 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
47 use util::logger::Logger;
48 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
49 use util::{byte_utils, events};
50 use util::events::Event;
52 use std::collections::{HashMap, HashSet, hash_map};
54 use std::{hash,cmp, mem};
58 /// An update generated by the underlying Channel itself which contains some new information the
59 /// ChannelMonitor should be made aware of.
60 #[cfg_attr(test, derive(PartialEq))]
63 pub struct ChannelMonitorUpdate {
64 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
65 /// The sequence number of this update. Updates *must* be replayed in-order according to this
66 /// sequence number (and updates may panic if they are not). The update_id values are strictly
67 /// increasing and increase by one for each new update.
69 /// This sequence number is also used to track up to which points updates which returned
70 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
71 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
75 impl Writeable for ChannelMonitorUpdate {
76 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
77 self.update_id.write(w)?;
78 (self.updates.len() as u64).write(w)?;
79 for update_step in self.updates.iter() {
80 update_step.write(w)?;
85 impl Readable for ChannelMonitorUpdate {
86 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
87 let update_id: u64 = Readable::read(r)?;
88 let len: u64 = Readable::read(r)?;
89 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
91 updates.push(Readable::read(r)?);
93 Ok(Self { update_id, updates })
97 /// An error enum representing a failure to persist a channel monitor update.
99 pub enum ChannelMonitorUpdateErr {
100 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
101 /// our state failed, but is expected to succeed at some point in the future).
103 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
104 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
105 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
106 /// restore the channel to an operational state.
108 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
109 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
110 /// writing out the latest ChannelManager state.
112 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
113 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
114 /// to claim it on this channel) and those updates must be applied wherever they can be. At
115 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
116 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
117 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
120 /// Note that even if updates made after TemporaryFailure succeed you must still call
121 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
124 /// Note that the update being processed here will not be replayed for you when you call
125 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
126 /// with the persisted ChannelMonitor on your own local disk prior to returning a
127 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
128 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
131 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
132 /// remote location (with local copies persisted immediately), it is anticipated that all
133 /// updates will return TemporaryFailure until the remote copies could be updated.
135 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
136 /// different watchtower and cannot update with all watchtowers that were previously informed
137 /// of this channel).
139 /// At reception of this error, ChannelManager will force-close the channel and return at
140 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
141 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
142 /// update must be rejected.
144 /// This failure may also signal a failure to update the local persisted copy of one of
145 /// the channel monitor instance.
147 /// Note that even when you fail a holder commitment transaction update, you must store the
148 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
149 /// broadcasts it (e.g distributed channel-monitor deployment)
151 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
152 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
153 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
154 /// lagging behind on block processing.
158 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
159 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
160 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
162 /// Contains a human-readable error message.
164 pub struct MonitorUpdateError(pub &'static str);
166 /// An event to be processed by the ChannelManager.
168 pub enum MonitorEvent {
169 /// A monitor event containing an HTLCUpdate.
170 HTLCEvent(HTLCUpdate),
172 /// A monitor event that the Channel's commitment transaction was broadcasted.
173 CommitmentTxBroadcasted(OutPoint),
176 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
177 /// forward channel and from which info are needed to update HTLC in a backward channel.
178 #[derive(Clone, PartialEq)]
179 pub struct HTLCUpdate {
180 pub(super) payment_hash: PaymentHash,
181 pub(super) payment_preimage: Option<PaymentPreimage>,
182 pub(super) source: HTLCSource
184 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
186 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
187 /// watchtower or watch our own channels.
189 /// Note that you must provide your own key by which to refer to channels.
191 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
192 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
193 /// index by a PublicKey which is required to sign any updates.
195 /// If you're using this for local monitoring of your own channels, you probably want to use
196 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
198 /// (C-not exported) due to an unconstrained generic in `Key`
199 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref>
200 where T::Target: BroadcasterInterface,
201 F::Target: FeeEstimator,
205 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
206 watch_events: Mutex<WatchEventQueue>,
212 struct WatchEventQueue {
213 watched: ChainWatchedUtil,
214 events: Vec<chain::WatchEvent>,
217 impl WatchEventQueue {
220 watched: ChainWatchedUtil::new(),
225 fn watch_tx(&mut self, txid: &Txid, script_pubkey: &Script) {
226 if self.watched.register_tx(txid, script_pubkey) {
227 self.events.push(chain::WatchEvent::WatchTransaction {
229 script_pubkey: script_pubkey.clone()
234 fn watch_output(&mut self, outpoint: (&Txid, usize), script_pubkey: &Script) {
235 let (txid, index) = outpoint;
236 if self.watched.register_outpoint((*txid, index as u32), script_pubkey) {
237 self.events.push(chain::WatchEvent::WatchOutput {
242 script_pubkey: script_pubkey.clone(),
247 fn dequeue_events(&mut self) -> Vec<chain::WatchEvent> {
248 let mut pending_events = Vec::with_capacity(self.events.len());
249 pending_events.append(&mut self.events);
253 fn filter_block<'a>(&self, txdata: &[(usize, &'a Transaction)]) -> Vec<(usize, &'a Transaction)> {
254 let mut matched_txids = HashSet::new();
255 txdata.iter().filter(|&&(_, tx)| {
256 // A tx matches the filter if it either matches the filter directly (via does_match_tx)
257 // or if it is a descendant of another matched transaction within the same block.
258 let mut matched = self.watched.does_match_tx(tx);
259 for input in tx.input.iter() {
260 if matched || matched_txids.contains(&input.previous_output.txid) {
266 matched_txids.insert(tx.txid());
269 }).map(|e| *e).collect()
273 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send>
274 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L>
275 where T::Target: BroadcasterInterface,
276 F::Target: FeeEstimator,
279 fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) {
280 let mut watch_events = self.watch_events.lock().unwrap();
281 let matched_txn = watch_events.filter_block(txdata);
283 let mut monitors = self.monitors.lock().unwrap();
284 for monitor in monitors.values_mut() {
285 let txn_outputs = monitor.block_connected(header, &matched_txn, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
287 for (ref txid, ref outputs) in txn_outputs {
288 for (idx, output) in outputs.iter().enumerate() {
289 watch_events.watch_output((txid, idx), &output.script_pubkey);
296 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
297 let mut monitors = self.monitors.lock().unwrap();
298 for monitor in monitors.values_mut() {
299 monitor.block_disconnected(header, disconnected_height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
304 impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L>
305 where T::Target: BroadcasterInterface,
306 F::Target: FeeEstimator,
309 /// Creates a new object which can be used to monitor several channels given the chain
310 /// interface with which to register to receive notifications.
311 pub fn new(broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L> {
312 let res = SimpleManyChannelMonitor {
313 monitors: Mutex::new(HashMap::new()),
314 watch_events: Mutex::new(WatchEventQueue::new()),
317 fee_estimator: feeest,
323 /// Adds or updates the monitor which monitors the channel referred to by the given key.
324 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
325 let mut watch_events = self.watch_events.lock().unwrap();
326 let mut monitors = self.monitors.lock().unwrap();
327 let entry = match monitors.entry(key) {
328 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
329 hash_map::Entry::Vacant(e) => e,
332 let funding_txo = monitor.get_funding_txo();
333 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
334 watch_events.watch_tx(&funding_txo.0.txid, &funding_txo.1);
335 watch_events.watch_output((&funding_txo.0.txid, funding_txo.0.index as usize), &funding_txo.1);
336 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
337 for (idx, script) in outputs.iter().enumerate() {
338 watch_events.watch_output((txid, idx), script);
342 entry.insert(monitor);
346 /// Updates the monitor which monitors the channel referred to by the given key.
347 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
348 let mut monitors = self.monitors.lock().unwrap();
349 match monitors.get_mut(&key) {
350 Some(orig_monitor) => {
351 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
352 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
354 None => Err(MonitorUpdateError("No such monitor registered"))
359 impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F, L>
360 where T::Target: BroadcasterInterface,
361 F::Target: FeeEstimator,
364 type Keys = ChanSigner;
366 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
367 match self.add_monitor_by_key(funding_txo, monitor) {
369 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
373 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
374 match self.update_monitor_by_key(funding_txo, update) {
376 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
380 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
381 let mut pending_monitor_events = Vec::new();
382 for chan in self.monitors.lock().unwrap().values_mut() {
383 pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events());
385 pending_monitor_events
389 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L>
390 where T::Target: BroadcasterInterface,
391 F::Target: FeeEstimator,
394 fn get_and_clear_pending_events(&self) -> Vec<Event> {
395 let mut pending_events = Vec::new();
396 for chan in self.monitors.lock().unwrap().values_mut() {
397 pending_events.append(&mut chan.get_and_clear_pending_events());
403 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> chain::WatchEventProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L>
404 where T::Target: BroadcasterInterface,
405 F::Target: FeeEstimator,
408 fn release_pending_watch_events(&self) -> Vec<chain::WatchEvent> {
409 self.watch_events.lock().unwrap().dequeue_events()
413 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
414 /// instead claiming it in its own individual transaction.
415 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
416 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
417 /// HTLC-Success transaction.
418 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
419 /// transaction confirmed (and we use it in a few more, equivalent, places).
420 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
421 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
422 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
423 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
424 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
425 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
426 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
427 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
428 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
429 /// accurate block height.
430 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
431 /// with at worst this delay, so we are not only using this value as a mercy for them but also
432 /// us as a safeguard to delay with enough time.
433 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
434 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
435 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
436 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
437 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
438 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
439 /// keeping bumping another claim tx to solve the outpoint.
440 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
441 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
442 /// refuse to accept a new HTLC.
444 /// This is used for a few separate purposes:
445 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
446 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
448 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
449 /// condition with the above), we will fail this HTLC without telling the user we received it,
450 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
451 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
453 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
454 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
456 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
457 /// in a race condition between the user connecting a block (which would fail it) and the user
458 /// providing us the preimage (which would claim it).
460 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
461 /// end up force-closing the channel on us to claim it.
462 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
464 #[derive(Clone, PartialEq)]
465 struct HolderSignedTx {
466 /// txid of the transaction in tx, just used to make comparison faster
468 revocation_key: PublicKey,
469 a_htlc_key: PublicKey,
470 b_htlc_key: PublicKey,
471 delayed_payment_key: PublicKey,
472 per_commitment_point: PublicKey,
474 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
477 /// We use this to track counterparty commitment transactions and htlcs outputs and
478 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
480 struct CounterpartyCommitmentTransaction {
481 counterparty_delayed_payment_base_key: PublicKey,
482 counterparty_htlc_base_key: PublicKey,
483 on_counterparty_tx_csv: u16,
484 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
487 impl Writeable for CounterpartyCommitmentTransaction {
488 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
489 self.counterparty_delayed_payment_base_key.write(w)?;
490 self.counterparty_htlc_base_key.write(w)?;
491 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
492 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
493 for (ref txid, ref htlcs) in self.per_htlc.iter() {
494 w.write_all(&txid[..])?;
495 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
496 for &ref htlc in htlcs.iter() {
503 impl Readable for CounterpartyCommitmentTransaction {
504 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
505 let counterparty_commitment_transaction = {
506 let counterparty_delayed_payment_base_key = Readable::read(r)?;
507 let counterparty_htlc_base_key = Readable::read(r)?;
508 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
509 let per_htlc_len: u64 = Readable::read(r)?;
510 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
511 for _ in 0..per_htlc_len {
512 let txid: Txid = Readable::read(r)?;
513 let htlcs_count: u64 = Readable::read(r)?;
514 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
515 for _ in 0..htlcs_count {
516 let htlc = Readable::read(r)?;
519 if let Some(_) = per_htlc.insert(txid, htlcs) {
520 return Err(DecodeError::InvalidValue);
523 CounterpartyCommitmentTransaction {
524 counterparty_delayed_payment_base_key,
525 counterparty_htlc_base_key,
526 on_counterparty_tx_csv,
530 Ok(counterparty_commitment_transaction)
534 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
535 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
536 /// a new bumped one in case of lenghty confirmation delay
537 #[derive(Clone, PartialEq)]
538 pub(crate) enum InputMaterial {
540 per_commitment_point: PublicKey,
541 counterparty_delayed_payment_base_key: PublicKey,
542 counterparty_htlc_base_key: PublicKey,
543 per_commitment_key: SecretKey,
544 input_descriptor: InputDescriptors,
546 htlc: Option<HTLCOutputInCommitment>,
547 on_counterparty_tx_csv: u16,
550 per_commitment_point: PublicKey,
551 counterparty_delayed_payment_base_key: PublicKey,
552 counterparty_htlc_base_key: PublicKey,
553 preimage: Option<PaymentPreimage>,
554 htlc: HTLCOutputInCommitment
557 preimage: Option<PaymentPreimage>,
561 funding_redeemscript: Script,
565 impl Writeable for InputMaterial {
566 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
568 &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv} => {
569 writer.write_all(&[0; 1])?;
570 per_commitment_point.write(writer)?;
571 counterparty_delayed_payment_base_key.write(writer)?;
572 counterparty_htlc_base_key.write(writer)?;
573 writer.write_all(&per_commitment_key[..])?;
574 input_descriptor.write(writer)?;
575 writer.write_all(&byte_utils::be64_to_array(*amount))?;
577 on_counterparty_tx_csv.write(writer)?;
579 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
580 writer.write_all(&[1; 1])?;
581 per_commitment_point.write(writer)?;
582 counterparty_delayed_payment_base_key.write(writer)?;
583 counterparty_htlc_base_key.write(writer)?;
584 preimage.write(writer)?;
587 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
588 writer.write_all(&[2; 1])?;
589 preimage.write(writer)?;
590 writer.write_all(&byte_utils::be64_to_array(*amount))?;
592 &InputMaterial::Funding { ref funding_redeemscript } => {
593 writer.write_all(&[3; 1])?;
594 funding_redeemscript.write(writer)?;
601 impl Readable for InputMaterial {
602 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
603 let input_material = match <u8 as Readable>::read(reader)? {
605 let per_commitment_point = Readable::read(reader)?;
606 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
607 let counterparty_htlc_base_key = Readable::read(reader)?;
608 let per_commitment_key = Readable::read(reader)?;
609 let input_descriptor = Readable::read(reader)?;
610 let amount = Readable::read(reader)?;
611 let htlc = Readable::read(reader)?;
612 let on_counterparty_tx_csv = Readable::read(reader)?;
613 InputMaterial::Revoked {
614 per_commitment_point,
615 counterparty_delayed_payment_base_key,
616 counterparty_htlc_base_key,
621 on_counterparty_tx_csv
625 let per_commitment_point = Readable::read(reader)?;
626 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
627 let counterparty_htlc_base_key = Readable::read(reader)?;
628 let preimage = Readable::read(reader)?;
629 let htlc = Readable::read(reader)?;
630 InputMaterial::CounterpartyHTLC {
631 per_commitment_point,
632 counterparty_delayed_payment_base_key,
633 counterparty_htlc_base_key,
639 let preimage = Readable::read(reader)?;
640 let amount = Readable::read(reader)?;
641 InputMaterial::HolderHTLC {
647 InputMaterial::Funding {
648 funding_redeemscript: Readable::read(reader)?,
651 _ => return Err(DecodeError::InvalidValue),
657 /// ClaimRequest is a descriptor structure to communicate between detection
658 /// and reaction module. They are generated by ChannelMonitor while parsing
659 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
660 /// is responsible for opportunistic aggregation, selecting and enforcing
661 /// bumping logic, building and signing transactions.
662 pub(crate) struct ClaimRequest {
663 // Block height before which claiming is exclusive to one party,
664 // after reaching it, claiming may be contentious.
665 pub(crate) absolute_timelock: u32,
666 // Timeout tx must have nLocktime set which means aggregating multiple
667 // ones must take the higher nLocktime among them to satisfy all of them.
668 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
669 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
670 // Do simplify we mark them as non-aggregable.
671 pub(crate) aggregable: bool,
672 // Basic bitcoin outpoint (txid, vout)
673 pub(crate) outpoint: BitcoinOutPoint,
674 // Following outpoint type, set of data needed to generate transaction digest
675 // and satisfy witness program.
676 pub(crate) witness_data: InputMaterial
679 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
680 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
681 #[derive(Clone, PartialEq)]
683 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
684 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
685 /// only win from it, so it's never an OnchainEvent
687 htlc_update: (HTLCSource, PaymentHash),
690 descriptor: SpendableOutputDescriptor,
694 const SERIALIZATION_VERSION: u8 = 1;
695 const MIN_SERIALIZATION_VERSION: u8 = 1;
697 #[cfg_attr(test, derive(PartialEq))]
699 pub(super) enum ChannelMonitorUpdateStep {
700 LatestHolderCommitmentTXInfo {
701 commitment_tx: HolderCommitmentTransaction,
702 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
704 LatestCounterpartyCommitmentTXInfo {
705 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
706 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
707 commitment_number: u64,
708 their_revocation_point: PublicKey,
711 payment_preimage: PaymentPreimage,
717 /// Used to indicate that the no future updates will occur, and likely that the latest holder
718 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
720 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
721 /// think we've fallen behind!
722 should_broadcast: bool,
726 impl Writeable for ChannelMonitorUpdateStep {
727 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
729 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
731 commitment_tx.write(w)?;
732 (htlc_outputs.len() as u64).write(w)?;
733 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
739 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
741 unsigned_commitment_tx.write(w)?;
742 commitment_number.write(w)?;
743 their_revocation_point.write(w)?;
744 (htlc_outputs.len() as u64).write(w)?;
745 for &(ref output, ref source) in htlc_outputs.iter() {
747 source.as_ref().map(|b| b.as_ref()).write(w)?;
750 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
752 payment_preimage.write(w)?;
754 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
759 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
761 should_broadcast.write(w)?;
767 impl Readable for ChannelMonitorUpdateStep {
768 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
769 match Readable::read(r)? {
771 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
772 commitment_tx: Readable::read(r)?,
774 let len: u64 = Readable::read(r)?;
775 let mut res = Vec::new();
777 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
784 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
785 unsigned_commitment_tx: Readable::read(r)?,
786 commitment_number: Readable::read(r)?,
787 their_revocation_point: Readable::read(r)?,
789 let len: u64 = Readable::read(r)?;
790 let mut res = Vec::new();
792 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
799 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
800 payment_preimage: Readable::read(r)?,
804 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
805 idx: Readable::read(r)?,
806 secret: Readable::read(r)?,
810 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
811 should_broadcast: Readable::read(r)?
814 _ => Err(DecodeError::InvalidValue),
819 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
820 /// on-chain transactions to ensure no loss of funds occurs.
822 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
823 /// information and are actively monitoring the chain.
825 /// Pending Events or updated HTLCs which have not yet been read out by
826 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
827 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
828 /// gotten are fully handled before re-serializing the new state.
829 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
830 latest_update_id: u64,
831 commitment_transaction_number_obscure_factor: u64,
833 destination_script: Script,
834 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
835 counterparty_payment_script: Script,
836 shutdown_script: Script,
839 funding_info: (OutPoint, Script),
840 current_counterparty_commitment_txid: Option<Txid>,
841 prev_counterparty_commitment_txid: Option<Txid>,
843 counterparty_tx_cache: CounterpartyCommitmentTransaction,
844 funding_redeemscript: Script,
845 channel_value_satoshis: u64,
846 // first is the idx of the first of the two revocation points
847 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
849 on_holder_tx_csv: u16,
851 commitment_secrets: CounterpartyCommitmentSecrets,
852 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
853 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
854 /// Nor can we figure out their commitment numbers without the commitment transaction they are
855 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
856 /// commitment transactions which we find on-chain, mapping them to the commitment number which
857 /// can be used to derive the revocation key and claim the transactions.
858 counterparty_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
859 /// Cache used to make pruning of payment_preimages faster.
860 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
861 /// counterparty transactions (ie should remain pretty small).
862 /// Serialized to disk but should generally not be sent to Watchtowers.
863 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
865 // We store two holder commitment transactions to avoid any race conditions where we may update
866 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
867 // various monitors for one channel being out of sync, and us broadcasting a holder
868 // transaction for which we have deleted claim information on some watchtowers.
869 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
870 current_holder_commitment_tx: HolderSignedTx,
872 // Used just for ChannelManager to make sure it has the latest channel data during
874 current_counterparty_commitment_number: u64,
875 // Used just for ChannelManager to make sure it has the latest channel data during
877 current_holder_commitment_number: u64,
879 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
881 pending_monitor_events: Vec<MonitorEvent>,
882 pending_events: Vec<Event>,
884 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
885 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
886 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
887 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
889 // If we get serialized out and re-read, we need to make sure that the chain monitoring
890 // interface knows about the TXOs that we want to be notified of spends of. We could probably
891 // be smart and derive them from the above storage fields, but its much simpler and more
892 // Obviously Correct (tm) if we just keep track of them explicitly.
893 outputs_to_watch: HashMap<Txid, Vec<Script>>,
896 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
898 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
900 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
901 // channel has been force-closed. After this is set, no further holder commitment transaction
902 // updates may occur, and we panic!() if one is provided.
903 lockdown_from_offchain: bool,
905 // Set once we've signed a holder commitment transaction and handed it over to our
906 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
907 // may occur, and we fail any such monitor updates.
909 // In case of update rejection due to a locally already signed commitment transaction, we
910 // nevertheless store update content to track in case of concurrent broadcast by another
911 // remote monitor out-of-order with regards to the block view.
912 holder_tx_signed: bool,
914 // We simply modify last_block_hash in Channel's block_connected so that serialization is
915 // consistent but hopefully the users' copy handles block_connected in a consistent way.
916 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
917 // their last_block_hash from its state and not based on updated copies that didn't run through
918 // the full block_connected).
919 last_block_hash: BlockHash,
920 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
923 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
924 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
925 /// events to it, while also taking any add/update_monitor events and passing them to some remote
928 /// In general, you must always have at least one local copy in memory, which must never fail to
929 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
930 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
931 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
932 /// taking any further action such as writing the current state to disk. This should likely be
933 /// accomplished via panic!() or abort().
935 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
936 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
937 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
938 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
940 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
941 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
942 /// than calling these methods directly, the user should register implementors as listeners to the
943 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
944 /// all registered listeners in one go.
945 pub trait ManyChannelMonitor: Send + Sync {
946 /// The concrete type which signs for transactions and provides access to our channel public
948 type Keys: ChannelKeys;
950 /// Adds a monitor for the given `funding_txo`.
952 /// Implementations must ensure that `monitor` receives block_connected calls for blocks with
953 /// the funding transaction or any spends of it, as well as any spends of outputs returned by
954 /// get_outputs_to_watch. Not doing so may result in LOST FUNDS.
955 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
957 /// Updates a monitor for the given `funding_txo`.
958 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
960 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
961 /// with success or failure.
963 /// You should probably just call through to
964 /// ChannelMonitor::get_and_clear_pending_monitor_events() for each ChannelMonitor and return
966 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent>;
969 #[cfg(any(test, feature = "fuzztarget"))]
970 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
971 /// underlying object
972 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
973 fn eq(&self, other: &Self) -> bool {
974 if self.latest_update_id != other.latest_update_id ||
975 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
976 self.destination_script != other.destination_script ||
977 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
978 self.counterparty_payment_script != other.counterparty_payment_script ||
979 self.keys.pubkeys() != other.keys.pubkeys() ||
980 self.funding_info != other.funding_info ||
981 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
982 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
983 self.counterparty_tx_cache != other.counterparty_tx_cache ||
984 self.funding_redeemscript != other.funding_redeemscript ||
985 self.channel_value_satoshis != other.channel_value_satoshis ||
986 self.their_cur_revocation_points != other.their_cur_revocation_points ||
987 self.on_holder_tx_csv != other.on_holder_tx_csv ||
988 self.commitment_secrets != other.commitment_secrets ||
989 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
990 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
991 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
992 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
993 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
994 self.current_holder_commitment_number != other.current_holder_commitment_number ||
995 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
996 self.payment_preimages != other.payment_preimages ||
997 self.pending_monitor_events != other.pending_monitor_events ||
998 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
999 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
1000 self.outputs_to_watch != other.outputs_to_watch ||
1001 self.lockdown_from_offchain != other.lockdown_from_offchain ||
1002 self.holder_tx_signed != other.holder_tx_signed
1011 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
1012 /// Writes this monitor into the given writer, suitable for writing to disk.
1014 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1015 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1016 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
1017 /// returned block hash and the the current chain and then reconnecting blocks to get to the
1018 /// best chain) upon deserializing the object!
1019 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
1020 //TODO: We still write out all the serialization here manually instead of using the fancy
1021 //serialization framework we have, we should migrate things over to it.
1022 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
1023 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
1025 self.latest_update_id.write(writer)?;
1027 // Set in initial Channel-object creation, so should always be set by now:
1028 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
1030 self.destination_script.write(writer)?;
1031 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
1032 writer.write_all(&[0; 1])?;
1033 broadcasted_holder_revokable_script.0.write(writer)?;
1034 broadcasted_holder_revokable_script.1.write(writer)?;
1035 broadcasted_holder_revokable_script.2.write(writer)?;
1037 writer.write_all(&[1; 1])?;
1040 self.counterparty_payment_script.write(writer)?;
1041 self.shutdown_script.write(writer)?;
1043 self.keys.write(writer)?;
1044 writer.write_all(&self.funding_info.0.txid[..])?;
1045 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
1046 self.funding_info.1.write(writer)?;
1047 self.current_counterparty_commitment_txid.write(writer)?;
1048 self.prev_counterparty_commitment_txid.write(writer)?;
1050 self.counterparty_tx_cache.write(writer)?;
1051 self.funding_redeemscript.write(writer)?;
1052 self.channel_value_satoshis.write(writer)?;
1054 match self.their_cur_revocation_points {
1055 Some((idx, pubkey, second_option)) => {
1056 writer.write_all(&byte_utils::be48_to_array(idx))?;
1057 writer.write_all(&pubkey.serialize())?;
1058 match second_option {
1059 Some(second_pubkey) => {
1060 writer.write_all(&second_pubkey.serialize())?;
1063 writer.write_all(&[0; 33])?;
1068 writer.write_all(&byte_utils::be48_to_array(0))?;
1072 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
1074 self.commitment_secrets.write(writer)?;
1076 macro_rules! serialize_htlc_in_commitment {
1077 ($htlc_output: expr) => {
1078 writer.write_all(&[$htlc_output.offered as u8; 1])?;
1079 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
1080 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
1081 writer.write_all(&$htlc_output.payment_hash.0[..])?;
1082 $htlc_output.transaction_output_index.write(writer)?;
1086 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
1087 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
1088 writer.write_all(&txid[..])?;
1089 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
1090 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
1091 serialize_htlc_in_commitment!(htlc_output);
1092 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1096 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
1097 for (ref txid, &(commitment_number, ref txouts)) in self.counterparty_commitment_txn_on_chain.iter() {
1098 writer.write_all(&txid[..])?;
1099 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
1100 (txouts.len() as u64).write(writer)?;
1101 for script in txouts.iter() {
1102 script.write(writer)?;
1106 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
1107 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
1108 writer.write_all(&payment_hash.0[..])?;
1109 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1112 macro_rules! serialize_holder_tx {
1113 ($holder_tx: expr) => {
1114 $holder_tx.txid.write(writer)?;
1115 writer.write_all(&$holder_tx.revocation_key.serialize())?;
1116 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
1117 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
1118 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
1119 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
1121 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
1122 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
1123 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
1124 serialize_htlc_in_commitment!(htlc_output);
1125 if let &Some(ref their_sig) = sig {
1127 writer.write_all(&their_sig.serialize_compact())?;
1131 htlc_source.write(writer)?;
1136 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
1137 writer.write_all(&[1; 1])?;
1138 serialize_holder_tx!(prev_holder_tx);
1140 writer.write_all(&[0; 1])?;
1143 serialize_holder_tx!(self.current_holder_commitment_tx);
1145 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
1146 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
1148 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1149 for payment_preimage in self.payment_preimages.values() {
1150 writer.write_all(&payment_preimage.0[..])?;
1153 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
1154 for event in self.pending_monitor_events.iter() {
1156 MonitorEvent::HTLCEvent(upd) => {
1160 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
1164 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1165 for event in self.pending_events.iter() {
1166 event.write(writer)?;
1169 self.last_block_hash.write(writer)?;
1171 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1172 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1173 writer.write_all(&byte_utils::be32_to_array(**target))?;
1174 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1175 for ev in events.iter() {
1177 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1179 htlc_update.0.write(writer)?;
1180 htlc_update.1.write(writer)?;
1182 OnchainEvent::MaturingOutput { ref descriptor } => {
1184 descriptor.write(writer)?;
1190 (self.outputs_to_watch.len() as u64).write(writer)?;
1191 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1192 txid.write(writer)?;
1193 (output_scripts.len() as u64).write(writer)?;
1194 for script in output_scripts.iter() {
1195 script.write(writer)?;
1198 self.onchain_tx_handler.write(writer)?;
1200 self.lockdown_from_offchain.write(writer)?;
1201 self.holder_tx_signed.write(writer)?;
1207 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1208 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1209 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1210 counterparty_htlc_base_key: &PublicKey, counterparty_delayed_payment_base_key: &PublicKey,
1211 on_holder_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1212 commitment_transaction_number_obscure_factor: u64,
1213 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1215 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1216 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1217 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1218 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1219 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1221 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key: *counterparty_delayed_payment_base_key, counterparty_htlc_base_key: *counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
1223 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_holder_tx_csv);
1225 let holder_tx_sequence = initial_holder_commitment_tx.unsigned_tx.input[0].sequence as u64;
1226 let holder_tx_locktime = initial_holder_commitment_tx.unsigned_tx.lock_time as u64;
1227 let holder_commitment_tx = HolderSignedTx {
1228 txid: initial_holder_commitment_tx.txid(),
1229 revocation_key: initial_holder_commitment_tx.keys.revocation_key,
1230 a_htlc_key: initial_holder_commitment_tx.keys.broadcaster_htlc_key,
1231 b_htlc_key: initial_holder_commitment_tx.keys.countersignatory_htlc_key,
1232 delayed_payment_key: initial_holder_commitment_tx.keys.broadcaster_delayed_payment_key,
1233 per_commitment_point: initial_holder_commitment_tx.keys.per_commitment_point,
1234 feerate_per_kw: initial_holder_commitment_tx.feerate_per_kw,
1235 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1237 onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx);
1240 latest_update_id: 0,
1241 commitment_transaction_number_obscure_factor,
1243 destination_script: destination_script.clone(),
1244 broadcasted_holder_revokable_script: None,
1245 counterparty_payment_script,
1250 current_counterparty_commitment_txid: None,
1251 prev_counterparty_commitment_txid: None,
1253 counterparty_tx_cache,
1254 funding_redeemscript,
1255 channel_value_satoshis: channel_value_satoshis,
1256 their_cur_revocation_points: None,
1260 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1261 counterparty_claimable_outpoints: HashMap::new(),
1262 counterparty_commitment_txn_on_chain: HashMap::new(),
1263 counterparty_hash_commitment_number: HashMap::new(),
1265 prev_holder_signed_commitment_tx: None,
1266 current_holder_commitment_tx: holder_commitment_tx,
1267 current_counterparty_commitment_number: 1 << 48,
1268 current_holder_commitment_number: 0xffff_ffff_ffff - ((((holder_tx_sequence & 0xffffff) << 3*8) | (holder_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1270 payment_preimages: HashMap::new(),
1271 pending_monitor_events: Vec::new(),
1272 pending_events: Vec::new(),
1274 onchain_events_waiting_threshold_conf: HashMap::new(),
1275 outputs_to_watch: HashMap::new(),
1279 lockdown_from_offchain: false,
1280 holder_tx_signed: false,
1282 last_block_hash: Default::default(),
1283 secp_ctx: Secp256k1::new(),
1287 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1288 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1289 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1290 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1291 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1292 return Err(MonitorUpdateError("Previous secret did not match new one"));
1295 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1296 // events for now-revoked/fulfilled HTLCs.
1297 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1298 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1303 if !self.payment_preimages.is_empty() {
1304 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1305 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1306 let min_idx = self.get_min_seen_secret();
1307 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1309 self.payment_preimages.retain(|&k, _| {
1310 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1311 if k == htlc.payment_hash {
1315 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1316 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1317 if k == htlc.payment_hash {
1322 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1329 counterparty_hash_commitment_number.remove(&k);
1338 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1339 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1340 /// possibly future revocation/preimage information) to claim outputs where possible.
1341 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1342 pub(super) fn provide_latest_counterparty_commitment_tx_info<L: Deref>(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1343 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1344 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1345 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1347 for &(ref htlc, _) in &htlc_outputs {
1348 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1351 let new_txid = unsigned_commitment_tx.txid();
1352 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1353 log_trace!(logger, "New potential counterparty commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1354 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1355 self.current_counterparty_commitment_txid = Some(new_txid);
1356 self.counterparty_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1357 self.current_counterparty_commitment_number = commitment_number;
1358 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1359 match self.their_cur_revocation_points {
1360 Some(old_points) => {
1361 if old_points.0 == commitment_number + 1 {
1362 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1363 } else if old_points.0 == commitment_number + 2 {
1364 if let Some(old_second_point) = old_points.2 {
1365 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1367 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1370 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1374 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1377 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1378 for htlc in htlc_outputs {
1379 if htlc.0.transaction_output_index.is_some() {
1383 self.counterparty_tx_cache.per_htlc.insert(new_txid, htlcs);
1386 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1387 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1388 /// is important that any clones of this channel monitor (including remote clones) by kept
1389 /// up-to-date as our holder commitment transaction is updated.
1390 /// Panics if set_on_holder_tx_csv has never been called.
1391 pub(super) fn provide_latest_holder_commitment_tx_info(&mut self, commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1392 let txid = commitment_tx.txid();
1393 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1394 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1395 let mut new_holder_commitment_tx = HolderSignedTx {
1397 revocation_key: commitment_tx.keys.revocation_key,
1398 a_htlc_key: commitment_tx.keys.broadcaster_htlc_key,
1399 b_htlc_key: commitment_tx.keys.countersignatory_htlc_key,
1400 delayed_payment_key: commitment_tx.keys.broadcaster_delayed_payment_key,
1401 per_commitment_point: commitment_tx.keys.per_commitment_point,
1402 feerate_per_kw: commitment_tx.feerate_per_kw,
1403 htlc_outputs: htlc_outputs,
1405 self.onchain_tx_handler.provide_latest_holder_tx(commitment_tx);
1406 self.current_holder_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1407 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1408 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1409 if self.holder_tx_signed {
1410 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1415 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1416 /// commitment_tx_infos which contain the payment hash have been revoked.
1417 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1418 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1421 pub(super) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1422 where B::Target: BroadcasterInterface,
1425 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1426 broadcaster.broadcast_transaction(tx);
1428 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1431 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1434 /// panics if the given update is not the next update by update_id.
1435 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1436 where B::Target: BroadcasterInterface,
1439 if self.latest_update_id + 1 != updates.update_id {
1440 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1442 for update in updates.updates.drain(..) {
1444 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1445 if self.lockdown_from_offchain { panic!(); }
1446 self.provide_latest_holder_commitment_tx_info(commitment_tx, htlc_outputs)?
1448 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1449 self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1450 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1451 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1452 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1453 self.provide_secret(idx, secret)?,
1454 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1455 self.lockdown_from_offchain = true;
1456 if should_broadcast {
1457 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1459 log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
1464 self.latest_update_id = updates.update_id;
1468 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1470 pub fn get_latest_update_id(&self) -> u64 {
1471 self.latest_update_id
1474 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1475 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1479 /// Gets a list of txids, with their output scripts (in the order they appear in the
1480 /// transaction), which we must learn about spends of via block_connected().
1482 /// (C-not exported) because we have no HashMap bindings
1483 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1484 &self.outputs_to_watch
1487 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1488 /// Generally useful when deserializing as during normal operation the return values of
1489 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1490 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1492 /// (C-not exported) as there is no practical way to track lifetimes of returned values.
1493 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1494 let mut res = Vec::with_capacity(self.counterparty_commitment_txn_on_chain.len() * 2);
1495 for (ref txid, &(_, ref outputs)) in self.counterparty_commitment_txn_on_chain.iter() {
1496 for (idx, output) in outputs.iter().enumerate() {
1497 res.push(((*txid).clone(), idx as u32, output));
1503 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1504 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_monitor_events().
1505 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1506 let mut ret = Vec::new();
1507 mem::swap(&mut ret, &mut self.pending_monitor_events);
1511 /// Gets the list of pending events which were generated by previous actions, clearing the list
1514 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1515 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1516 /// no internal locking in ChannelMonitors.
1517 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1518 let mut ret = Vec::new();
1519 mem::swap(&mut ret, &mut self.pending_events);
1523 /// Can only fail if idx is < get_min_seen_secret
1524 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1525 self.commitment_secrets.get_secret(idx)
1528 pub(super) fn get_min_seen_secret(&self) -> u64 {
1529 self.commitment_secrets.get_min_seen_secret()
1532 pub(super) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1533 self.current_counterparty_commitment_number
1536 pub(super) fn get_cur_holder_commitment_number(&self) -> u64 {
1537 self.current_holder_commitment_number
1540 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1541 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1542 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1543 /// HTLC-Success/HTLC-Timeout transactions.
1544 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1545 /// revoked counterparty commitment tx
1546 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1547 // Most secp and related errors trying to create keys means we have no hope of constructing
1548 // a spend transaction...so we return no transactions to broadcast
1549 let mut claimable_outpoints = Vec::new();
1550 let mut watch_outputs = Vec::new();
1552 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1553 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1555 macro_rules! ignore_error {
1556 ( $thing : expr ) => {
1559 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1564 let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1565 if commitment_number >= self.get_min_seen_secret() {
1566 let secret = self.get_secret(commitment_number).unwrap();
1567 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1568 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1569 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1570 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_tx_cache.counterparty_delayed_payment_base_key));
1572 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1573 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1575 // First, process non-htlc outputs (to_holder & to_counterparty)
1576 for (idx, outp) in tx.output.iter().enumerate() {
1577 if outp.script_pubkey == revokeable_p2wsh {
1578 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1579 claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
1583 // Then, try to find revoked htlc outputs
1584 if let Some(ref per_commitment_data) = per_commitment_option {
1585 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1586 if let Some(transaction_output_index) = htlc.transaction_output_index {
1587 if transaction_output_index as usize >= tx.output.len() ||
1588 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1589 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1591 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value, htlc: Some(htlc.clone()), on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1592 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1597 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1598 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1599 // We're definitely a counterparty commitment transaction!
1600 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1601 watch_outputs.append(&mut tx.output.clone());
1602 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1604 macro_rules! check_htlc_fails {
1605 ($txid: expr, $commitment_tx: expr) => {
1606 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1607 for &(ref htlc, ref source_option) in outpoints.iter() {
1608 if let &Some(ref source) = source_option {
1609 log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1610 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1611 hash_map::Entry::Occupied(mut entry) => {
1612 let e = entry.get_mut();
1613 e.retain(|ref event| {
1615 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1616 return htlc_update.0 != **source
1621 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1623 hash_map::Entry::Vacant(entry) => {
1624 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1632 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1633 check_htlc_fails!(txid, "current");
1635 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1636 check_htlc_fails!(txid, "counterparty");
1638 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1640 } else if let Some(per_commitment_data) = per_commitment_option {
1641 // While this isn't useful yet, there is a potential race where if a counterparty
1642 // revokes a state at the same time as the commitment transaction for that state is
1643 // confirmed, and the watchtower receives the block before the user, the user could
1644 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1645 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1646 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1648 watch_outputs.append(&mut tx.output.clone());
1649 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1651 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1653 macro_rules! check_htlc_fails {
1654 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1655 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1656 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1657 if let &Some(ref source) = source_option {
1658 // Check if the HTLC is present in the commitment transaction that was
1659 // broadcast, but not if it was below the dust limit, which we should
1660 // fail backwards immediately as there is no way for us to learn the
1661 // payment_preimage.
1662 // Note that if the dust limit were allowed to change between
1663 // commitment transactions we'd want to be check whether *any*
1664 // broadcastable commitment transaction has the HTLC in it, but it
1665 // cannot currently change after channel initialization, so we don't
1667 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1668 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1672 log_trace!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of counterparty commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1673 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1674 hash_map::Entry::Occupied(mut entry) => {
1675 let e = entry.get_mut();
1676 e.retain(|ref event| {
1678 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1679 return htlc_update.0 != **source
1684 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1686 hash_map::Entry::Vacant(entry) => {
1687 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1695 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1696 check_htlc_fails!(txid, "current", 'current_loop);
1698 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1699 check_htlc_fails!(txid, "previous", 'prev_loop);
1702 if let Some(revocation_points) = self.their_cur_revocation_points {
1703 let revocation_point_option =
1704 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1705 else if let Some(point) = revocation_points.2.as_ref() {
1706 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1708 if let Some(revocation_point) = revocation_point_option {
1709 self.counterparty_payment_script = {
1710 // Note that the Network here is ignored as we immediately drop the address for the
1711 // script_pubkey version
1712 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1713 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1716 // Then, try to find htlc outputs
1717 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1718 if let Some(transaction_output_index) = htlc.transaction_output_index {
1719 if transaction_output_index as usize >= tx.output.len() ||
1720 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1721 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1723 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1724 let aggregable = if !htlc.offered { false } else { true };
1725 if preimage.is_some() || !htlc.offered {
1726 let witness_data = InputMaterial::CounterpartyHTLC { per_commitment_point: *revocation_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, preimage, htlc: htlc.clone() };
1727 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1734 (claimable_outpoints, (commitment_txid, watch_outputs))
1737 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1738 fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<TxOut>)>) where L::Target: Logger {
1739 let htlc_txid = tx.txid();
1740 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1741 return (Vec::new(), None)
1744 macro_rules! ignore_error {
1745 ( $thing : expr ) => {
1748 Err(_) => return (Vec::new(), None)
1753 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1754 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1755 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1757 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1758 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv };
1759 let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
1760 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1763 fn broadcast_by_holder_state(&self, commitment_tx: &Transaction, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1764 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1765 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1767 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1768 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1770 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1771 if let Some(transaction_output_index) = htlc.transaction_output_index {
1772 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1773 witness_data: InputMaterial::HolderHTLC {
1774 preimage: if !htlc.offered {
1775 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1776 Some(preimage.clone())
1778 // We can't build an HTLC-Success transaction without the preimage
1782 amount: htlc.amount_msat,
1784 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1788 (claim_requests, watch_outputs, broadcasted_holder_revokable_script)
1791 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1792 /// revoked using data in holder_claimable_outpoints.
1793 /// Should not be used if check_spend_revoked_transaction succeeds.
1794 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1795 let commitment_txid = tx.txid();
1796 let mut claim_requests = Vec::new();
1797 let mut watch_outputs = Vec::new();
1799 macro_rules! wait_threshold_conf {
1800 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1801 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1802 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1803 hash_map::Entry::Occupied(mut entry) => {
1804 let e = entry.get_mut();
1805 e.retain(|ref event| {
1807 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1808 return htlc_update.0 != $source
1813 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1815 hash_map::Entry::Vacant(entry) => {
1816 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1822 macro_rules! append_onchain_update {
1823 ($updates: expr) => {
1824 claim_requests = $updates.0;
1825 watch_outputs.append(&mut $updates.1);
1826 self.broadcasted_holder_revokable_script = $updates.2;
1830 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1831 let mut is_holder_tx = false;
1833 if self.current_holder_commitment_tx.txid == commitment_txid {
1834 is_holder_tx = true;
1835 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1836 let mut res = self.broadcast_by_holder_state(tx, &self.current_holder_commitment_tx);
1837 append_onchain_update!(res);
1838 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1839 if holder_tx.txid == commitment_txid {
1840 is_holder_tx = true;
1841 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1842 let mut res = self.broadcast_by_holder_state(tx, holder_tx);
1843 append_onchain_update!(res);
1847 macro_rules! fail_dust_htlcs_after_threshold_conf {
1848 ($holder_tx: expr) => {
1849 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1850 if htlc.transaction_output_index.is_none() {
1851 if let &Some(ref source) = source {
1852 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1860 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1861 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1862 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1866 (claim_requests, (commitment_txid, watch_outputs))
1869 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1870 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1871 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1872 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1873 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1874 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1875 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1876 /// out-of-band the other node operator to coordinate with him if option is available to you.
1877 /// In any-case, choice is up to the user.
1878 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1879 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1880 self.holder_tx_signed = true;
1881 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1882 let txid = commitment_tx.txid();
1883 let mut res = vec![commitment_tx];
1884 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1885 if let Some(vout) = htlc.0.transaction_output_index {
1886 let preimage = if !htlc.0.offered {
1887 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1888 // We can't build an HTLC-Success transaction without the preimage
1892 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1893 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1898 // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
1899 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1905 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1906 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1907 /// revoked commitment transaction.
1908 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1909 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1910 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1911 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
1912 let txid = commitment_tx.txid();
1913 let mut res = vec![commitment_tx];
1914 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1915 if let Some(vout) = htlc.0.transaction_output_index {
1916 let preimage = if !htlc.0.offered {
1917 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1918 // We can't build an HTLC-Success transaction without the preimage
1922 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1923 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1933 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1934 /// ChainListener::block_connected.
1935 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1936 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1938 fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txn_matched: &[(usize, &Transaction)], height: u32, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<TxOut>)>
1939 where B::Target: BroadcasterInterface,
1940 F::Target: FeeEstimator,
1943 for &(_, tx) in txn_matched {
1944 let mut output_val = 0;
1945 for out in tx.output.iter() {
1946 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1947 output_val += out.value;
1948 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1952 let block_hash = header.block_hash();
1953 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1955 let mut watch_outputs = Vec::new();
1956 let mut claimable_outpoints = Vec::new();
1957 for &(_, tx) in txn_matched {
1958 if tx.input.len() == 1 {
1959 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1960 // commitment transactions and HTLC transactions will all only ever have one input,
1961 // which is an easy way to filter out any potential non-matching txn for lazy
1963 let prevout = &tx.input[0].previous_output;
1964 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1965 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1966 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1967 if !new_outputs.1.is_empty() {
1968 watch_outputs.push(new_outputs);
1970 if new_outpoints.is_empty() {
1971 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1972 if !new_outputs.1.is_empty() {
1973 watch_outputs.push(new_outputs);
1975 claimable_outpoints.append(&mut new_outpoints);
1977 claimable_outpoints.append(&mut new_outpoints);
1980 if let Some(&(commitment_number, _)) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1981 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1982 claimable_outpoints.append(&mut new_outpoints);
1983 if let Some(new_outputs) = new_outputs_option {
1984 watch_outputs.push(new_outputs);
1989 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1990 // can also be resolved in a few other ways which can have more than one output. Thus,
1991 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1992 self.is_resolving_htlc_output(&tx, height, &logger);
1994 self.is_paying_spendable_output(&tx, height, &logger);
1996 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1997 if should_broadcast {
1998 claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.funding_info.0.txid.clone(), vout: self.funding_info.0.index as u32 }, witness_data: InputMaterial::Funding { funding_redeemscript: self.funding_redeemscript.clone() }});
2000 if should_broadcast {
2001 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
2002 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
2003 self.holder_tx_signed = true;
2004 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_holder_state(&commitment_tx, &self.current_holder_commitment_tx);
2005 if !new_outputs.is_empty() {
2006 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2008 claimable_outpoints.append(&mut new_outpoints);
2011 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
2014 OnchainEvent::HTLCUpdate { htlc_update } => {
2015 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
2016 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2017 payment_hash: htlc_update.1,
2018 payment_preimage: None,
2019 source: htlc_update.0,
2022 OnchainEvent::MaturingOutput { descriptor } => {
2023 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2024 self.pending_events.push(Event::SpendableOutputs {
2025 outputs: vec![descriptor]
2032 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
2034 self.last_block_hash = block_hash;
2035 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
2036 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
2042 fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2043 where B::Target: BroadcasterInterface,
2044 F::Target: FeeEstimator,
2047 let block_hash = header.block_hash();
2048 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
2050 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
2052 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2053 //- maturing spendable output has transaction paying us has been disconnected
2056 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2058 self.last_block_hash = block_hash;
2061 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2062 // We need to consider all HTLCs which are:
2063 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2064 // transactions and we'd end up in a race, or
2065 // * are in our latest holder commitment transaction, as this is the thing we will
2066 // broadcast if we go on-chain.
2067 // Note that we consider HTLCs which were below dust threshold here - while they don't
2068 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2069 // to the source, and if we don't fail the channel we will have to ensure that the next
2070 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2071 // easier to just fail the channel as this case should be rare enough anyway.
2072 macro_rules! scan_commitment {
2073 ($htlcs: expr, $holder_tx: expr) => {
2074 for ref htlc in $htlcs {
2075 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2076 // chain with enough room to claim the HTLC without our counterparty being able to
2077 // time out the HTLC first.
2078 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2079 // concern is being able to claim the corresponding inbound HTLC (on another
2080 // channel) before it expires. In fact, we don't even really care if our
2081 // counterparty here claims such an outbound HTLC after it expired as long as we
2082 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2083 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2084 // we give ourselves a few blocks of headroom after expiration before going
2085 // on-chain for an expired HTLC.
2086 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2087 // from us until we've reached the point where we go on-chain with the
2088 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2089 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2090 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2091 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2092 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2093 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2094 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2095 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2096 // The final, above, condition is checked for statically in channelmanager
2097 // with CHECK_CLTV_EXPIRY_SANITY_2.
2098 let htlc_outbound = $holder_tx == htlc.offered;
2099 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2100 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2101 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2108 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2110 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2111 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2112 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2115 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2116 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2117 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2124 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2125 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2126 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2127 'outer_loop: for input in &tx.input {
2128 let mut payment_data = None;
2129 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2130 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2131 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2132 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2134 macro_rules! log_claim {
2135 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2136 // We found the output in question, but aren't failing it backwards
2137 // as we have no corresponding source and no valid counterparty commitment txid
2138 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2139 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2140 let outbound_htlc = $holder_tx == $htlc.offered;
2141 if ($holder_tx && revocation_sig_claim) ||
2142 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2143 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2144 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2145 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2146 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2148 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2149 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2150 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2151 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2156 macro_rules! check_htlc_valid_counterparty {
2157 ($counterparty_txid: expr, $htlc_output: expr) => {
2158 if let Some(txid) = $counterparty_txid {
2159 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2160 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2161 if let &Some(ref source) = pending_source {
2162 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2163 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2172 macro_rules! scan_commitment {
2173 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2174 for (ref htlc_output, source_option) in $htlcs {
2175 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2176 if let Some(ref source) = source_option {
2177 log_claim!($tx_info, $holder_tx, htlc_output, true);
2178 // We have a resolution of an HTLC either from one of our latest
2179 // holder commitment transactions or an unrevoked counterparty commitment
2180 // transaction. This implies we either learned a preimage, the HTLC
2181 // has timed out, or we screwed up. In any case, we should now
2182 // resolve the source HTLC with the original sender.
2183 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2184 } else if !$holder_tx {
2185 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2186 if payment_data.is_none() {
2187 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2190 if payment_data.is_none() {
2191 log_claim!($tx_info, $holder_tx, htlc_output, false);
2192 continue 'outer_loop;
2199 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2200 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2201 "our latest holder commitment tx", true);
2203 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2204 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2205 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2206 "our previous holder commitment tx", true);
2209 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2210 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2211 "counterparty commitment tx", false);
2214 // Check that scan_commitment, above, decided there is some source worth relaying an
2215 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2216 if let Some((source, payment_hash)) = payment_data {
2217 let mut payment_preimage = PaymentPreimage([0; 32]);
2218 if accepted_preimage_claim {
2219 if !self.pending_monitor_events.iter().any(
2220 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2221 payment_preimage.0.copy_from_slice(&input.witness[3]);
2222 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2224 payment_preimage: Some(payment_preimage),
2228 } else if offered_preimage_claim {
2229 if !self.pending_monitor_events.iter().any(
2230 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2231 upd.source == source
2233 payment_preimage.0.copy_from_slice(&input.witness[1]);
2234 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2236 payment_preimage: Some(payment_preimage),
2241 log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), height + ANTI_REORG_DELAY - 1);
2242 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2243 hash_map::Entry::Occupied(mut entry) => {
2244 let e = entry.get_mut();
2245 e.retain(|ref event| {
2247 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2248 return htlc_update.0 != source
2253 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2255 hash_map::Entry::Vacant(entry) => {
2256 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2264 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2265 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2266 let mut spendable_output = None;
2267 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2268 if i > ::std::u16::MAX as usize {
2269 // While it is possible that an output exists on chain which is greater than the
2270 // 2^16th output in a given transaction, this is only possible if the output is not
2271 // in a lightning transaction and was instead placed there by some third party who
2272 // wishes to give us money for no reason.
2273 // Namely, any lightning transactions which we pre-sign will never have anywhere
2274 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2275 // scripts are not longer than one byte in length and because they are inherently
2276 // non-standard due to their size.
2277 // Thus, it is completely safe to ignore such outputs, and while it may result in
2278 // us ignoring non-lightning fund to us, that is only possible if someone fills
2279 // nearly a full block with garbage just to hit this case.
2282 if outp.script_pubkey == self.destination_script {
2283 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2284 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2285 output: outp.clone(),
2288 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2289 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2290 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2291 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2292 per_commitment_point: broadcasted_holder_revokable_script.1,
2293 to_self_delay: self.on_holder_tx_csv,
2294 output: outp.clone(),
2295 key_derivation_params: self.keys.key_derivation_params(),
2296 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2300 } else if self.counterparty_payment_script == outp.script_pubkey {
2301 spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
2302 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2303 output: outp.clone(),
2304 key_derivation_params: self.keys.key_derivation_params(),
2307 } else if outp.script_pubkey == self.shutdown_script {
2308 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2309 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2310 output: outp.clone(),
2314 if let Some(spendable_output) = spendable_output {
2315 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2316 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2317 hash_map::Entry::Occupied(mut entry) => {
2318 let e = entry.get_mut();
2319 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2321 hash_map::Entry::Vacant(entry) => {
2322 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2329 const MAX_ALLOC_SIZE: usize = 64*1024;
2331 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2332 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2333 macro_rules! unwrap_obj {
2337 Err(_) => return Err(DecodeError::InvalidValue),
2342 let _ver: u8 = Readable::read(reader)?;
2343 let min_ver: u8 = Readable::read(reader)?;
2344 if min_ver > SERIALIZATION_VERSION {
2345 return Err(DecodeError::UnknownVersion);
2348 let latest_update_id: u64 = Readable::read(reader)?;
2349 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2351 let destination_script = Readable::read(reader)?;
2352 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2354 let revokable_address = Readable::read(reader)?;
2355 let per_commitment_point = Readable::read(reader)?;
2356 let revokable_script = Readable::read(reader)?;
2357 Some((revokable_address, per_commitment_point, revokable_script))
2360 _ => return Err(DecodeError::InvalidValue),
2362 let counterparty_payment_script = Readable::read(reader)?;
2363 let shutdown_script = Readable::read(reader)?;
2365 let keys = Readable::read(reader)?;
2366 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2367 // barely-init'd ChannelMonitors that we can't do anything with.
2368 let outpoint = OutPoint {
2369 txid: Readable::read(reader)?,
2370 index: Readable::read(reader)?,
2372 let funding_info = (outpoint, Readable::read(reader)?);
2373 let current_counterparty_commitment_txid = Readable::read(reader)?;
2374 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2376 let counterparty_tx_cache = Readable::read(reader)?;
2377 let funding_redeemscript = Readable::read(reader)?;
2378 let channel_value_satoshis = Readable::read(reader)?;
2380 let their_cur_revocation_points = {
2381 let first_idx = <U48 as Readable>::read(reader)?.0;
2385 let first_point = Readable::read(reader)?;
2386 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2387 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2388 Some((first_idx, first_point, None))
2390 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2395 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2397 let commitment_secrets = Readable::read(reader)?;
2399 macro_rules! read_htlc_in_commitment {
2402 let offered: bool = Readable::read(reader)?;
2403 let amount_msat: u64 = Readable::read(reader)?;
2404 let cltv_expiry: u32 = Readable::read(reader)?;
2405 let payment_hash: PaymentHash = Readable::read(reader)?;
2406 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2408 HTLCOutputInCommitment {
2409 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2415 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2416 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2417 for _ in 0..counterparty_claimable_outpoints_len {
2418 let txid: Txid = Readable::read(reader)?;
2419 let htlcs_count: u64 = Readable::read(reader)?;
2420 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2421 for _ in 0..htlcs_count {
2422 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2424 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2425 return Err(DecodeError::InvalidValue);
2429 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2430 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2431 for _ in 0..counterparty_commitment_txn_on_chain_len {
2432 let txid: Txid = Readable::read(reader)?;
2433 let commitment_number = <U48 as Readable>::read(reader)?.0;
2434 let outputs_count = <u64 as Readable>::read(reader)?;
2435 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2436 for _ in 0..outputs_count {
2437 outputs.push(Readable::read(reader)?);
2439 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2440 return Err(DecodeError::InvalidValue);
2444 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2445 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2446 for _ in 0..counterparty_hash_commitment_number_len {
2447 let payment_hash: PaymentHash = Readable::read(reader)?;
2448 let commitment_number = <U48 as Readable>::read(reader)?.0;
2449 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2450 return Err(DecodeError::InvalidValue);
2454 macro_rules! read_holder_tx {
2457 let txid = Readable::read(reader)?;
2458 let revocation_key = Readable::read(reader)?;
2459 let a_htlc_key = Readable::read(reader)?;
2460 let b_htlc_key = Readable::read(reader)?;
2461 let delayed_payment_key = Readable::read(reader)?;
2462 let per_commitment_point = Readable::read(reader)?;
2463 let feerate_per_kw: u32 = Readable::read(reader)?;
2465 let htlcs_len: u64 = Readable::read(reader)?;
2466 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2467 for _ in 0..htlcs_len {
2468 let htlc = read_htlc_in_commitment!();
2469 let sigs = match <u8 as Readable>::read(reader)? {
2471 1 => Some(Readable::read(reader)?),
2472 _ => return Err(DecodeError::InvalidValue),
2474 htlcs.push((htlc, sigs, Readable::read(reader)?));
2479 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2486 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2489 Some(read_holder_tx!())
2491 _ => return Err(DecodeError::InvalidValue),
2493 let current_holder_commitment_tx = read_holder_tx!();
2495 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2496 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2498 let payment_preimages_len: u64 = Readable::read(reader)?;
2499 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2500 for _ in 0..payment_preimages_len {
2501 let preimage: PaymentPreimage = Readable::read(reader)?;
2502 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2503 if let Some(_) = payment_preimages.insert(hash, preimage) {
2504 return Err(DecodeError::InvalidValue);
2508 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2509 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2510 for _ in 0..pending_monitor_events_len {
2511 let ev = match <u8 as Readable>::read(reader)? {
2512 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2513 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2514 _ => return Err(DecodeError::InvalidValue)
2516 pending_monitor_events.push(ev);
2519 let pending_events_len: u64 = Readable::read(reader)?;
2520 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2521 for _ in 0..pending_events_len {
2522 if let Some(event) = MaybeReadable::read(reader)? {
2523 pending_events.push(event);
2527 let last_block_hash: BlockHash = Readable::read(reader)?;
2529 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2530 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2531 for _ in 0..waiting_threshold_conf_len {
2532 let height_target = Readable::read(reader)?;
2533 let events_len: u64 = Readable::read(reader)?;
2534 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2535 for _ in 0..events_len {
2536 let ev = match <u8 as Readable>::read(reader)? {
2538 let htlc_source = Readable::read(reader)?;
2539 let hash = Readable::read(reader)?;
2540 OnchainEvent::HTLCUpdate {
2541 htlc_update: (htlc_source, hash)
2545 let descriptor = Readable::read(reader)?;
2546 OnchainEvent::MaturingOutput {
2550 _ => return Err(DecodeError::InvalidValue),
2554 onchain_events_waiting_threshold_conf.insert(height_target, events);
2557 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2558 let mut outputs_to_watch = HashMap::with_capacity(cmp::min(outputs_to_watch_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<Txid>() + mem::size_of::<Vec<Script>>())));
2559 for _ in 0..outputs_to_watch_len {
2560 let txid = Readable::read(reader)?;
2561 let outputs_len: u64 = Readable::read(reader)?;
2562 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2563 for _ in 0..outputs_len {
2564 outputs.push(Readable::read(reader)?);
2566 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2567 return Err(DecodeError::InvalidValue);
2570 let onchain_tx_handler = Readable::read(reader)?;
2572 let lockdown_from_offchain = Readable::read(reader)?;
2573 let holder_tx_signed = Readable::read(reader)?;
2575 Ok((last_block_hash.clone(), ChannelMonitor {
2577 commitment_transaction_number_obscure_factor,
2580 broadcasted_holder_revokable_script,
2581 counterparty_payment_script,
2586 current_counterparty_commitment_txid,
2587 prev_counterparty_commitment_txid,
2589 counterparty_tx_cache,
2590 funding_redeemscript,
2591 channel_value_satoshis,
2592 their_cur_revocation_points,
2597 counterparty_claimable_outpoints,
2598 counterparty_commitment_txn_on_chain,
2599 counterparty_hash_commitment_number,
2601 prev_holder_signed_commitment_tx,
2602 current_holder_commitment_tx,
2603 current_counterparty_commitment_number,
2604 current_holder_commitment_number,
2607 pending_monitor_events,
2610 onchain_events_waiting_threshold_conf,
2615 lockdown_from_offchain,
2619 secp_ctx: Secp256k1::new(),
2626 use bitcoin::blockdata::script::{Script, Builder};
2627 use bitcoin::blockdata::opcodes;
2628 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2629 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2630 use bitcoin::util::bip143;
2631 use bitcoin::hashes::Hash;
2632 use bitcoin::hashes::sha256::Hash as Sha256;
2633 use bitcoin::hashes::hex::FromHex;
2634 use bitcoin::hash_types::Txid;
2636 use chain::transaction::OutPoint;
2637 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2638 use ln::channelmonitor::ChannelMonitor;
2639 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2641 use ln::chan_utils::{HTLCOutputInCommitment, HolderCommitmentTransaction};
2642 use util::test_utils::TestLogger;
2643 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2644 use bitcoin::secp256k1::Secp256k1;
2646 use chain::keysinterface::InMemoryChannelKeys;
2649 fn test_prune_preimages() {
2650 let secp_ctx = Secp256k1::new();
2651 let logger = Arc::new(TestLogger::new());
2653 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2654 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2656 let mut preimages = Vec::new();
2659 let preimage = PaymentPreimage([i; 32]);
2660 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2661 preimages.push((preimage, hash));
2665 macro_rules! preimages_slice_to_htlc_outputs {
2666 ($preimages_slice: expr) => {
2668 let mut res = Vec::new();
2669 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2670 res.push((HTLCOutputInCommitment {
2674 payment_hash: preimage.1.clone(),
2675 transaction_output_index: Some(idx as u32),
2682 macro_rules! preimages_to_holder_htlcs {
2683 ($preimages_slice: expr) => {
2685 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2686 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2692 macro_rules! test_preimages_exist {
2693 ($preimages_slice: expr, $monitor: expr) => {
2694 for preimage in $preimages_slice {
2695 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2700 let keys = InMemoryChannelKeys::new(
2702 SecretKey::from_slice(&[41; 32]).unwrap(),
2703 SecretKey::from_slice(&[41; 32]).unwrap(),
2704 SecretKey::from_slice(&[41; 32]).unwrap(),
2705 SecretKey::from_slice(&[41; 32]).unwrap(),
2706 SecretKey::from_slice(&[41; 32]).unwrap(),
2712 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2714 let mut monitor = ChannelMonitor::new(keys,
2715 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2716 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2717 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2718 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2719 10, Script::new(), 46, 0, HolderCommitmentTransaction::dummy());
2721 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2722 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2723 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2724 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2725 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2726 for &(ref preimage, ref hash) in preimages.iter() {
2727 monitor.provide_payment_preimage(hash, preimage);
2730 // Now provide a secret, pruning preimages 10-15
2731 let mut secret = [0; 32];
2732 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2733 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2734 assert_eq!(monitor.payment_preimages.len(), 15);
2735 test_preimages_exist!(&preimages[0..10], monitor);
2736 test_preimages_exist!(&preimages[15..20], monitor);
2738 // Now provide a further secret, pruning preimages 15-17
2739 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2740 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2741 assert_eq!(monitor.payment_preimages.len(), 13);
2742 test_preimages_exist!(&preimages[0..10], monitor);
2743 test_preimages_exist!(&preimages[17..20], monitor);
2745 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2746 // previous commitment tx's preimages too
2747 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2748 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2749 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2750 assert_eq!(monitor.payment_preimages.len(), 12);
2751 test_preimages_exist!(&preimages[0..10], monitor);
2752 test_preimages_exist!(&preimages[18..20], monitor);
2754 // But if we do it again, we'll prune 5-10
2755 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2756 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2757 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2758 assert_eq!(monitor.payment_preimages.len(), 5);
2759 test_preimages_exist!(&preimages[0..5], monitor);
2763 fn test_claim_txn_weight_computation() {
2764 // We test Claim txn weight, knowing that we want expected weigth and
2765 // not actual case to avoid sigs and time-lock delays hell variances.
2767 let secp_ctx = Secp256k1::new();
2768 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2769 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2770 let mut sum_actual_sigs = 0;
2772 macro_rules! sign_input {
2773 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2774 let htlc = HTLCOutputInCommitment {
2775 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2777 cltv_expiry: 2 << 16,
2778 payment_hash: PaymentHash([1; 32]),
2779 transaction_output_index: Some($idx as u32),
2781 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2782 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2783 let sig = secp_ctx.sign(&sighash, &privkey);
2784 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2785 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2786 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2787 if *$input_type == InputDescriptors::RevokedOutput {
2788 $sighash_parts.access_witness($idx).push(vec!(1));
2789 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2790 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2791 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2792 $sighash_parts.access_witness($idx).push(vec![0]);
2794 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2796 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2797 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2798 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2799 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2803 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2804 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2806 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2807 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2809 claim_tx.input.push(TxIn {
2810 previous_output: BitcoinOutPoint {
2814 script_sig: Script::new(),
2815 sequence: 0xfffffffd,
2816 witness: Vec::new(),
2819 claim_tx.output.push(TxOut {
2820 script_pubkey: script_pubkey.clone(),
2823 let base_weight = claim_tx.get_weight();
2824 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2826 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2827 for (idx, inp) in inputs_des.iter().enumerate() {
2828 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2831 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2833 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2834 claim_tx.input.clear();
2835 sum_actual_sigs = 0;
2837 claim_tx.input.push(TxIn {
2838 previous_output: BitcoinOutPoint {
2842 script_sig: Script::new(),
2843 sequence: 0xfffffffd,
2844 witness: Vec::new(),
2847 let base_weight = claim_tx.get_weight();
2848 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2850 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2851 for (idx, inp) in inputs_des.iter().enumerate() {
2852 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2855 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2857 // Justice tx with 1 revoked HTLC-Success tx output
2858 claim_tx.input.clear();
2859 sum_actual_sigs = 0;
2860 claim_tx.input.push(TxIn {
2861 previous_output: BitcoinOutPoint {
2865 script_sig: Script::new(),
2866 sequence: 0xfffffffd,
2867 witness: Vec::new(),
2869 let base_weight = claim_tx.get_weight();
2870 let inputs_des = vec![InputDescriptors::RevokedOutput];
2872 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2873 for (idx, inp) in inputs_des.iter().enumerate() {
2874 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2877 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
2880 // Further testing is done in the ChannelManager integration tests.