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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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, LocalCommitmentTransaction, HTLCType};
41 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
42 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
43 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator};
44 use chain::transaction::OutPoint;
45 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
46 use util::logger::Logger;
47 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
48 use util::{byte_utils, events};
49 use util::events::Event;
51 use std::collections::{HashMap, hash_map};
53 use std::{hash,cmp, mem};
57 /// An update generated by the underlying Channel itself which contains some new information the
58 /// ChannelMonitor should be made aware of.
59 #[cfg_attr(test, derive(PartialEq))]
62 pub struct ChannelMonitorUpdate {
63 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
64 /// The sequence number of this update. Updates *must* be replayed in-order according to this
65 /// sequence number (and updates may panic if they are not). The update_id values are strictly
66 /// increasing and increase by one for each new update.
68 /// This sequence number is also used to track up to which points updates which returned
69 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
70 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
74 impl Writeable for ChannelMonitorUpdate {
75 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
76 self.update_id.write(w)?;
77 (self.updates.len() as u64).write(w)?;
78 for update_step in self.updates.iter() {
79 update_step.write(w)?;
84 impl Readable for ChannelMonitorUpdate {
85 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
86 let update_id: u64 = Readable::read(r)?;
87 let len: u64 = Readable::read(r)?;
88 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
90 updates.push(Readable::read(r)?);
92 Ok(Self { update_id, updates })
96 /// An error enum representing a failure to persist a channel monitor update.
98 pub enum ChannelMonitorUpdateErr {
99 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
100 /// our state failed, but is expected to succeed at some point in the future).
102 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
103 /// submitting new commitment transactions to the remote party. Once the update(s) which failed
104 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
105 /// restore the channel to an operational state.
107 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
108 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
109 /// writing out the latest ChannelManager state.
111 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
112 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
113 /// to claim it on this channel) and those updates must be applied wherever they can be. At
114 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
115 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
116 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
119 /// Note that even if updates made after TemporaryFailure succeed you must still call
120 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
123 /// Note that the update being processed here will not be replayed for you when you call
124 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
125 /// with the persisted ChannelMonitor on your own local disk prior to returning a
126 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
127 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
130 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
131 /// remote location (with local copies persisted immediately), it is anticipated that all
132 /// updates will return TemporaryFailure until the remote copies could be updated.
134 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
135 /// different watchtower and cannot update with all watchtowers that were previously informed
136 /// of this channel). This will force-close the channel in question (which will generate one
137 /// final ChannelMonitorUpdate which must be delivered to at least one ChannelMonitor copy).
139 /// Should also be used to indicate a failure to update the local persisted copy of the channel
144 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
145 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
146 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
148 /// Contains a human-readable error message.
150 pub struct MonitorUpdateError(pub &'static str);
152 /// An event to be processed by the ChannelManager.
154 pub enum MonitorEvent {
155 /// A monitor event containing an HTLCUpdate.
156 HTLCEvent(HTLCUpdate),
158 /// A monitor event that the Channel's commitment transaction was broadcasted.
159 CommitmentTxBroadcasted(OutPoint),
162 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
163 /// forward channel and from which info are needed to update HTLC in a backward channel.
164 #[derive(Clone, PartialEq)]
165 pub struct HTLCUpdate {
166 pub(super) payment_hash: PaymentHash,
167 pub(super) payment_preimage: Option<PaymentPreimage>,
168 pub(super) source: HTLCSource
170 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
172 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
173 /// watchtower or watch our own channels.
175 /// Note that you must provide your own key by which to refer to channels.
177 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
178 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
179 /// index by a PublicKey which is required to sign any updates.
181 /// If you're using this for local monitoring of your own channels, you probably want to use
182 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
183 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref>
184 where T::Target: BroadcasterInterface,
185 F::Target: FeeEstimator,
187 C::Target: ChainWatchInterface,
190 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
197 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send>
198 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
199 where T::Target: BroadcasterInterface,
200 F::Target: FeeEstimator,
202 C::Target: ChainWatchInterface,
204 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[usize]) {
205 let block_hash = header.block_hash();
207 let mut monitors = self.monitors.lock().unwrap();
208 for monitor in monitors.values_mut() {
209 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
211 for (ref txid, ref outputs) in txn_outputs {
212 for (idx, output) in outputs.iter().enumerate() {
213 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
220 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
221 let block_hash = header.block_hash();
222 let mut monitors = self.monitors.lock().unwrap();
223 for monitor in monitors.values_mut() {
224 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
229 impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
230 where T::Target: BroadcasterInterface,
231 F::Target: FeeEstimator,
233 C::Target: ChainWatchInterface,
235 /// Creates a new object which can be used to monitor several channels given the chain
236 /// interface with which to register to receive notifications.
237 pub fn new(chain_monitor: C, broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C> {
238 let res = SimpleManyChannelMonitor {
239 monitors: Mutex::new(HashMap::new()),
243 fee_estimator: feeest,
249 /// Adds or updates the monitor which monitors the channel referred to by the given key.
250 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
251 let mut monitors = self.monitors.lock().unwrap();
252 let entry = match monitors.entry(key) {
253 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
254 hash_map::Entry::Vacant(e) => e,
257 let funding_txo = monitor.get_funding_txo();
258 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
259 self.chain_monitor.install_watch_tx(&funding_txo.0.txid, &funding_txo.1);
260 self.chain_monitor.install_watch_outpoint((funding_txo.0.txid, funding_txo.0.index as u32), &funding_txo.1);
261 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
262 for (idx, script) in outputs.iter().enumerate() {
263 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
267 entry.insert(monitor);
271 /// Updates the monitor which monitors the channel referred to by the given key.
272 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
273 let mut monitors = self.monitors.lock().unwrap();
274 match monitors.get_mut(&key) {
275 Some(orig_monitor) => {
276 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
277 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
279 None => Err(MonitorUpdateError("No such monitor registered"))
284 impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send> ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F, L, C>
285 where T::Target: BroadcasterInterface,
286 F::Target: FeeEstimator,
288 C::Target: ChainWatchInterface,
290 type Keys = ChanSigner;
292 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
293 match self.add_monitor_by_key(funding_txo, monitor) {
295 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
299 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
300 match self.update_monitor_by_key(funding_txo, update) {
302 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
306 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
307 let mut pending_monitor_events = Vec::new();
308 for chan in self.monitors.lock().unwrap().values_mut() {
309 pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events());
311 pending_monitor_events
315 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
316 where T::Target: BroadcasterInterface,
317 F::Target: FeeEstimator,
319 C::Target: ChainWatchInterface,
321 fn get_and_clear_pending_events(&self) -> Vec<Event> {
322 let mut pending_events = Vec::new();
323 for chan in self.monitors.lock().unwrap().values_mut() {
324 pending_events.append(&mut chan.get_and_clear_pending_events());
330 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
331 /// instead claiming it in its own individual transaction.
332 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
333 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
334 /// HTLC-Success transaction.
335 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
336 /// transaction confirmed (and we use it in a few more, equivalent, places).
337 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
338 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
339 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
340 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
341 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
342 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
343 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
344 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
345 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
346 /// accurate block height.
347 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
348 /// with at worst this delay, so we are not only using this value as a mercy for them but also
349 /// us as a safeguard to delay with enough time.
350 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
351 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
352 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
353 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
354 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
355 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
356 /// keeping bumping another claim tx to solve the outpoint.
357 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
358 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
359 /// refuse to accept a new HTLC.
361 /// This is used for a few separate purposes:
362 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
363 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
365 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
366 /// condition with the above), we will fail this HTLC without telling the user we received it,
367 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
368 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
370 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
371 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
373 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
374 /// in a race condition between the user connecting a block (which would fail it) and the user
375 /// providing us the preimage (which would claim it).
377 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
378 /// end up force-closing the channel on us to claim it.
379 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
381 #[derive(Clone, PartialEq)]
382 struct LocalSignedTx {
383 /// txid of the transaction in tx, just used to make comparison faster
385 revocation_key: PublicKey,
386 a_htlc_key: PublicKey,
387 b_htlc_key: PublicKey,
388 delayed_payment_key: PublicKey,
389 per_commitment_point: PublicKey,
391 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
394 /// We use this to track remote commitment transactions and htlcs outputs and
395 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
397 struct RemoteCommitmentTransaction {
398 remote_delayed_payment_base_key: PublicKey,
399 remote_htlc_base_key: PublicKey,
400 on_remote_tx_csv: u16,
401 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
404 impl Writeable for RemoteCommitmentTransaction {
405 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
406 self.remote_delayed_payment_base_key.write(w)?;
407 self.remote_htlc_base_key.write(w)?;
408 w.write_all(&byte_utils::be16_to_array(self.on_remote_tx_csv))?;
409 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
410 for (ref txid, ref htlcs) in self.per_htlc.iter() {
411 w.write_all(&txid[..])?;
412 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
413 for &ref htlc in htlcs.iter() {
420 impl Readable for RemoteCommitmentTransaction {
421 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
422 let remote_commitment_transaction = {
423 let remote_delayed_payment_base_key = Readable::read(r)?;
424 let remote_htlc_base_key = Readable::read(r)?;
425 let on_remote_tx_csv: u16 = Readable::read(r)?;
426 let per_htlc_len: u64 = Readable::read(r)?;
427 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
428 for _ in 0..per_htlc_len {
429 let txid: Txid = Readable::read(r)?;
430 let htlcs_count: u64 = Readable::read(r)?;
431 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
432 for _ in 0..htlcs_count {
433 let htlc = Readable::read(r)?;
436 if let Some(_) = per_htlc.insert(txid, htlcs) {
437 return Err(DecodeError::InvalidValue);
440 RemoteCommitmentTransaction {
441 remote_delayed_payment_base_key,
442 remote_htlc_base_key,
447 Ok(remote_commitment_transaction)
451 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
452 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
453 /// a new bumped one in case of lenghty confirmation delay
454 #[derive(Clone, PartialEq)]
455 pub(crate) enum InputMaterial {
457 per_commitment_point: PublicKey,
458 remote_delayed_payment_base_key: PublicKey,
459 remote_htlc_base_key: PublicKey,
460 per_commitment_key: SecretKey,
461 input_descriptor: InputDescriptors,
463 htlc: Option<HTLCOutputInCommitment>,
464 on_remote_tx_csv: u16,
467 per_commitment_point: PublicKey,
468 remote_delayed_payment_base_key: PublicKey,
469 remote_htlc_base_key: PublicKey,
470 preimage: Option<PaymentPreimage>,
471 htlc: HTLCOutputInCommitment
474 preimage: Option<PaymentPreimage>,
478 funding_redeemscript: Script,
482 impl Writeable for InputMaterial {
483 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
485 &InputMaterial::Revoked { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_remote_tx_csv} => {
486 writer.write_all(&[0; 1])?;
487 per_commitment_point.write(writer)?;
488 remote_delayed_payment_base_key.write(writer)?;
489 remote_htlc_base_key.write(writer)?;
490 writer.write_all(&per_commitment_key[..])?;
491 input_descriptor.write(writer)?;
492 writer.write_all(&byte_utils::be64_to_array(*amount))?;
494 on_remote_tx_csv.write(writer)?;
496 &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc} => {
497 writer.write_all(&[1; 1])?;
498 per_commitment_point.write(writer)?;
499 remote_delayed_payment_base_key.write(writer)?;
500 remote_htlc_base_key.write(writer)?;
501 preimage.write(writer)?;
504 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
505 writer.write_all(&[2; 1])?;
506 preimage.write(writer)?;
507 writer.write_all(&byte_utils::be64_to_array(*amount))?;
509 &InputMaterial::Funding { ref funding_redeemscript } => {
510 writer.write_all(&[3; 1])?;
511 funding_redeemscript.write(writer)?;
518 impl Readable for InputMaterial {
519 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
520 let input_material = match <u8 as Readable>::read(reader)? {
522 let per_commitment_point = Readable::read(reader)?;
523 let remote_delayed_payment_base_key = Readable::read(reader)?;
524 let remote_htlc_base_key = Readable::read(reader)?;
525 let per_commitment_key = Readable::read(reader)?;
526 let input_descriptor = Readable::read(reader)?;
527 let amount = Readable::read(reader)?;
528 let htlc = Readable::read(reader)?;
529 let on_remote_tx_csv = Readable::read(reader)?;
530 InputMaterial::Revoked {
531 per_commitment_point,
532 remote_delayed_payment_base_key,
533 remote_htlc_base_key,
542 let per_commitment_point = Readable::read(reader)?;
543 let remote_delayed_payment_base_key = Readable::read(reader)?;
544 let remote_htlc_base_key = Readable::read(reader)?;
545 let preimage = Readable::read(reader)?;
546 let htlc = Readable::read(reader)?;
547 InputMaterial::RemoteHTLC {
548 per_commitment_point,
549 remote_delayed_payment_base_key,
550 remote_htlc_base_key,
556 let preimage = Readable::read(reader)?;
557 let amount = Readable::read(reader)?;
558 InputMaterial::LocalHTLC {
564 InputMaterial::Funding {
565 funding_redeemscript: Readable::read(reader)?,
568 _ => return Err(DecodeError::InvalidValue),
574 /// ClaimRequest is a descriptor structure to communicate between detection
575 /// and reaction module. They are generated by ChannelMonitor while parsing
576 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
577 /// is responsible for opportunistic aggregation, selecting and enforcing
578 /// bumping logic, building and signing transactions.
579 pub(crate) struct ClaimRequest {
580 // Block height before which claiming is exclusive to one party,
581 // after reaching it, claiming may be contentious.
582 pub(crate) absolute_timelock: u32,
583 // Timeout tx must have nLocktime set which means aggregating multiple
584 // ones must take the higher nLocktime among them to satisfy all of them.
585 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
586 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
587 // Do simplify we mark them as non-aggregable.
588 pub(crate) aggregable: bool,
589 // Basic bitcoin outpoint (txid, vout)
590 pub(crate) outpoint: BitcoinOutPoint,
591 // Following outpoint type, set of data needed to generate transaction digest
592 // and satisfy witness program.
593 pub(crate) witness_data: InputMaterial
596 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
597 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
598 #[derive(Clone, PartialEq)]
600 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
601 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
602 /// only win from it, so it's never an OnchainEvent
604 htlc_update: (HTLCSource, PaymentHash),
607 descriptor: SpendableOutputDescriptor,
611 const SERIALIZATION_VERSION: u8 = 1;
612 const MIN_SERIALIZATION_VERSION: u8 = 1;
614 #[cfg_attr(test, derive(PartialEq))]
616 pub(super) enum ChannelMonitorUpdateStep {
617 LatestLocalCommitmentTXInfo {
618 commitment_tx: LocalCommitmentTransaction,
619 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
621 LatestRemoteCommitmentTXInfo {
622 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
623 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
624 commitment_number: u64,
625 their_revocation_point: PublicKey,
628 payment_preimage: PaymentPreimage,
634 /// Used to indicate that the no future updates will occur, and likely that the latest local
635 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
637 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
638 /// think we've fallen behind!
639 should_broadcast: bool,
643 impl Writeable for ChannelMonitorUpdateStep {
644 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
646 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
648 commitment_tx.write(w)?;
649 (htlc_outputs.len() as u64).write(w)?;
650 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
656 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
658 unsigned_commitment_tx.write(w)?;
659 commitment_number.write(w)?;
660 their_revocation_point.write(w)?;
661 (htlc_outputs.len() as u64).write(w)?;
662 for &(ref output, ref source) in htlc_outputs.iter() {
664 source.as_ref().map(|b| b.as_ref()).write(w)?;
667 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
669 payment_preimage.write(w)?;
671 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
676 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
678 should_broadcast.write(w)?;
684 impl Readable for ChannelMonitorUpdateStep {
685 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
686 match Readable::read(r)? {
688 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
689 commitment_tx: Readable::read(r)?,
691 let len: u64 = Readable::read(r)?;
692 let mut res = Vec::new();
694 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
701 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
702 unsigned_commitment_tx: Readable::read(r)?,
703 commitment_number: Readable::read(r)?,
704 their_revocation_point: Readable::read(r)?,
706 let len: u64 = Readable::read(r)?;
707 let mut res = Vec::new();
709 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
716 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
717 payment_preimage: Readable::read(r)?,
721 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
722 idx: Readable::read(r)?,
723 secret: Readable::read(r)?,
727 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
728 should_broadcast: Readable::read(r)?
731 _ => Err(DecodeError::InvalidValue),
736 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
737 /// on-chain transactions to ensure no loss of funds occurs.
739 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
740 /// information and are actively monitoring the chain.
742 /// Pending Events or updated HTLCs which have not yet been read out by
743 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
744 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
745 /// gotten are fully handled before re-serializing the new state.
746 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
747 latest_update_id: u64,
748 commitment_transaction_number_obscure_factor: u64,
750 destination_script: Script,
751 broadcasted_local_revokable_script: Option<(Script, PublicKey, PublicKey)>,
752 remote_payment_script: Script,
753 shutdown_script: Script,
756 funding_info: (OutPoint, Script),
757 current_remote_commitment_txid: Option<Txid>,
758 prev_remote_commitment_txid: Option<Txid>,
760 remote_tx_cache: RemoteCommitmentTransaction,
761 funding_redeemscript: Script,
762 channel_value_satoshis: u64,
763 // first is the idx of the first of the two revocation points
764 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
766 on_local_tx_csv: u16,
768 commitment_secrets: CounterpartyCommitmentSecrets,
769 remote_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
770 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
771 /// Nor can we figure out their commitment numbers without the commitment transaction they are
772 /// spending. Thus, in order to claim them via revocation key, we track all the remote
773 /// commitment transactions which we find on-chain, mapping them to the commitment number which
774 /// can be used to derive the revocation key and claim the transactions.
775 remote_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
776 /// Cache used to make pruning of payment_preimages faster.
777 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
778 /// remote transactions (ie should remain pretty small).
779 /// Serialized to disk but should generally not be sent to Watchtowers.
780 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
782 // We store two local commitment transactions to avoid any race conditions where we may update
783 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
784 // various monitors for one channel being out of sync, and us broadcasting a local
785 // transaction for which we have deleted claim information on some watchtowers.
786 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
787 current_local_commitment_tx: LocalSignedTx,
789 // Used just for ChannelManager to make sure it has the latest channel data during
791 current_remote_commitment_number: u64,
792 // Used just for ChannelManager to make sure it has the latest channel data during
794 current_local_commitment_number: u64,
796 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
798 pending_monitor_events: Vec<MonitorEvent>,
799 pending_events: Vec<Event>,
801 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
802 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
803 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
804 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
806 // If we get serialized out and re-read, we need to make sure that the chain monitoring
807 // interface knows about the TXOs that we want to be notified of spends of. We could probably
808 // be smart and derive them from the above storage fields, but its much simpler and more
809 // Obviously Correct (tm) if we just keep track of them explicitly.
810 outputs_to_watch: HashMap<Txid, Vec<Script>>,
813 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
815 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
817 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
818 // channel has been force-closed. After this is set, no further local commitment transaction
819 // updates may occur, and we panic!() if one is provided.
820 lockdown_from_offchain: bool,
822 // Set once we've signed a local commitment transaction and handed it over to our
823 // OnchainTxHandler. After this is set, no future updates to our local commitment transactions
824 // may occur, and we fail any such monitor updates.
825 local_tx_signed: bool,
827 // We simply modify last_block_hash in Channel's block_connected so that serialization is
828 // consistent but hopefully the users' copy handles block_connected in a consistent way.
829 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
830 // their last_block_hash from its state and not based on updated copies that didn't run through
831 // the full block_connected).
832 last_block_hash: BlockHash,
833 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
836 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
837 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
838 /// events to it, while also taking any add/update_monitor events and passing them to some remote
841 /// In general, you must always have at least one local copy in memory, which must never fail to
842 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
843 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
844 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
845 /// taking any further action such as writing the current state to disk. This should likely be
846 /// accomplished via panic!() or abort().
848 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
849 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
850 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
851 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
853 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
854 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
855 /// than calling these methods directly, the user should register implementors as listeners to the
856 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
857 /// all registered listeners in one go.
858 pub trait ManyChannelMonitor: Send + Sync {
859 /// The concrete type which signs for transactions and provides access to our channel public
861 type Keys: ChannelKeys;
863 /// Adds a monitor for the given `funding_txo`.
865 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
866 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
867 /// callbacks with the funding transaction, or any spends of it.
869 /// Further, the implementer must also ensure that each output returned in
870 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
871 /// any spends of any of the outputs.
873 /// Any spends of outputs which should have been registered which aren't passed to
874 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
875 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
877 /// Updates a monitor for the given `funding_txo`.
879 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
880 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
881 /// callbacks with the funding transaction, or any spends of it.
883 /// Further, the implementer must also ensure that each output returned in
884 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
885 /// any spends of any of the outputs.
887 /// Any spends of outputs which should have been registered which aren't passed to
888 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
889 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
891 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
892 /// with success or failure.
894 /// You should probably just call through to
895 /// ChannelMonitor::get_and_clear_pending_monitor_events() for each ChannelMonitor and return
897 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent>;
900 #[cfg(any(test, feature = "fuzztarget"))]
901 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
902 /// underlying object
903 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
904 fn eq(&self, other: &Self) -> bool {
905 if self.latest_update_id != other.latest_update_id ||
906 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
907 self.destination_script != other.destination_script ||
908 self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
909 self.remote_payment_script != other.remote_payment_script ||
910 self.keys.pubkeys() != other.keys.pubkeys() ||
911 self.funding_info != other.funding_info ||
912 self.current_remote_commitment_txid != other.current_remote_commitment_txid ||
913 self.prev_remote_commitment_txid != other.prev_remote_commitment_txid ||
914 self.remote_tx_cache != other.remote_tx_cache ||
915 self.funding_redeemscript != other.funding_redeemscript ||
916 self.channel_value_satoshis != other.channel_value_satoshis ||
917 self.their_cur_revocation_points != other.their_cur_revocation_points ||
918 self.on_local_tx_csv != other.on_local_tx_csv ||
919 self.commitment_secrets != other.commitment_secrets ||
920 self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
921 self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
922 self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
923 self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
924 self.current_remote_commitment_number != other.current_remote_commitment_number ||
925 self.current_local_commitment_number != other.current_local_commitment_number ||
926 self.current_local_commitment_tx != other.current_local_commitment_tx ||
927 self.payment_preimages != other.payment_preimages ||
928 self.pending_monitor_events != other.pending_monitor_events ||
929 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
930 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
931 self.outputs_to_watch != other.outputs_to_watch ||
932 self.lockdown_from_offchain != other.lockdown_from_offchain ||
933 self.local_tx_signed != other.local_tx_signed
942 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
943 /// Writes this monitor into the given writer, suitable for writing to disk.
945 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
946 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
947 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
948 /// returned block hash and the the current chain and then reconnecting blocks to get to the
949 /// best chain) upon deserializing the object!
950 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
951 //TODO: We still write out all the serialization here manually instead of using the fancy
952 //serialization framework we have, we should migrate things over to it.
953 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
954 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
956 self.latest_update_id.write(writer)?;
958 // Set in initial Channel-object creation, so should always be set by now:
959 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
961 self.destination_script.write(writer)?;
962 if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
963 writer.write_all(&[0; 1])?;
964 broadcasted_local_revokable_script.0.write(writer)?;
965 broadcasted_local_revokable_script.1.write(writer)?;
966 broadcasted_local_revokable_script.2.write(writer)?;
968 writer.write_all(&[1; 1])?;
971 self.remote_payment_script.write(writer)?;
972 self.shutdown_script.write(writer)?;
974 self.keys.write(writer)?;
975 writer.write_all(&self.funding_info.0.txid[..])?;
976 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
977 self.funding_info.1.write(writer)?;
978 self.current_remote_commitment_txid.write(writer)?;
979 self.prev_remote_commitment_txid.write(writer)?;
981 self.remote_tx_cache.write(writer)?;
982 self.funding_redeemscript.write(writer)?;
983 self.channel_value_satoshis.write(writer)?;
985 match self.their_cur_revocation_points {
986 Some((idx, pubkey, second_option)) => {
987 writer.write_all(&byte_utils::be48_to_array(idx))?;
988 writer.write_all(&pubkey.serialize())?;
989 match second_option {
990 Some(second_pubkey) => {
991 writer.write_all(&second_pubkey.serialize())?;
994 writer.write_all(&[0; 33])?;
999 writer.write_all(&byte_utils::be48_to_array(0))?;
1003 writer.write_all(&byte_utils::be16_to_array(self.on_local_tx_csv))?;
1005 self.commitment_secrets.write(writer)?;
1007 macro_rules! serialize_htlc_in_commitment {
1008 ($htlc_output: expr) => {
1009 writer.write_all(&[$htlc_output.offered as u8; 1])?;
1010 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
1011 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
1012 writer.write_all(&$htlc_output.payment_hash.0[..])?;
1013 $htlc_output.transaction_output_index.write(writer)?;
1017 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
1018 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
1019 writer.write_all(&txid[..])?;
1020 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
1021 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
1022 serialize_htlc_in_commitment!(htlc_output);
1023 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1027 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
1028 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
1029 writer.write_all(&txid[..])?;
1030 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
1031 (txouts.len() as u64).write(writer)?;
1032 for script in txouts.iter() {
1033 script.write(writer)?;
1037 writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
1038 for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
1039 writer.write_all(&payment_hash.0[..])?;
1040 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1043 macro_rules! serialize_local_tx {
1044 ($local_tx: expr) => {
1045 $local_tx.txid.write(writer)?;
1046 writer.write_all(&$local_tx.revocation_key.serialize())?;
1047 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
1048 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
1049 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
1050 writer.write_all(&$local_tx.per_commitment_point.serialize())?;
1052 writer.write_all(&byte_utils::be32_to_array($local_tx.feerate_per_kw))?;
1053 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
1054 for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
1055 serialize_htlc_in_commitment!(htlc_output);
1056 if let &Some(ref their_sig) = sig {
1058 writer.write_all(&their_sig.serialize_compact())?;
1062 htlc_source.write(writer)?;
1067 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
1068 writer.write_all(&[1; 1])?;
1069 serialize_local_tx!(prev_local_tx);
1071 writer.write_all(&[0; 1])?;
1074 serialize_local_tx!(self.current_local_commitment_tx);
1076 writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
1077 writer.write_all(&byte_utils::be48_to_array(self.current_local_commitment_number))?;
1079 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1080 for payment_preimage in self.payment_preimages.values() {
1081 writer.write_all(&payment_preimage.0[..])?;
1084 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
1085 for event in self.pending_monitor_events.iter() {
1087 MonitorEvent::HTLCEvent(upd) => {
1091 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
1095 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1096 for event in self.pending_events.iter() {
1097 event.write(writer)?;
1100 self.last_block_hash.write(writer)?;
1102 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1103 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1104 writer.write_all(&byte_utils::be32_to_array(**target))?;
1105 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1106 for ev in events.iter() {
1108 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1110 htlc_update.0.write(writer)?;
1111 htlc_update.1.write(writer)?;
1113 OnchainEvent::MaturingOutput { ref descriptor } => {
1115 descriptor.write(writer)?;
1121 (self.outputs_to_watch.len() as u64).write(writer)?;
1122 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1123 txid.write(writer)?;
1124 (output_scripts.len() as u64).write(writer)?;
1125 for script in output_scripts.iter() {
1126 script.write(writer)?;
1129 self.onchain_tx_handler.write(writer)?;
1131 self.lockdown_from_offchain.write(writer)?;
1132 self.local_tx_signed.write(writer)?;
1138 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1139 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1140 on_remote_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1141 remote_htlc_base_key: &PublicKey, remote_delayed_payment_base_key: &PublicKey,
1142 on_local_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1143 commitment_transaction_number_obscure_factor: u64,
1144 initial_local_commitment_tx: LocalCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1146 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1147 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1148 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1149 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1150 let remote_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1152 let remote_tx_cache = RemoteCommitmentTransaction { remote_delayed_payment_base_key: *remote_delayed_payment_base_key, remote_htlc_base_key: *remote_htlc_base_key, on_remote_tx_csv, per_htlc: HashMap::new() };
1154 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_local_tx_csv);
1156 let local_tx_sequence = initial_local_commitment_tx.unsigned_tx.input[0].sequence as u64;
1157 let local_tx_locktime = initial_local_commitment_tx.unsigned_tx.lock_time as u64;
1158 let local_commitment_tx = LocalSignedTx {
1159 txid: initial_local_commitment_tx.txid(),
1160 revocation_key: initial_local_commitment_tx.local_keys.revocation_key,
1161 a_htlc_key: initial_local_commitment_tx.local_keys.a_htlc_key,
1162 b_htlc_key: initial_local_commitment_tx.local_keys.b_htlc_key,
1163 delayed_payment_key: initial_local_commitment_tx.local_keys.a_delayed_payment_key,
1164 per_commitment_point: initial_local_commitment_tx.local_keys.per_commitment_point,
1165 feerate_per_kw: initial_local_commitment_tx.feerate_per_kw,
1166 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1168 // Returning a monitor error before updating tracking points means in case of using
1169 // a concurrent watchtower implementation for same channel, if this one doesn't
1170 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1171 // for which you want to spend outputs. We're NOT robust again this scenario right
1172 // now but we should consider it later.
1173 onchain_tx_handler.provide_latest_local_tx(initial_local_commitment_tx).unwrap();
1176 latest_update_id: 0,
1177 commitment_transaction_number_obscure_factor,
1179 destination_script: destination_script.clone(),
1180 broadcasted_local_revokable_script: None,
1181 remote_payment_script,
1186 current_remote_commitment_txid: None,
1187 prev_remote_commitment_txid: None,
1190 funding_redeemscript,
1191 channel_value_satoshis: channel_value_satoshis,
1192 their_cur_revocation_points: None,
1196 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1197 remote_claimable_outpoints: HashMap::new(),
1198 remote_commitment_txn_on_chain: HashMap::new(),
1199 remote_hash_commitment_number: HashMap::new(),
1201 prev_local_signed_commitment_tx: None,
1202 current_local_commitment_tx: local_commitment_tx,
1203 current_remote_commitment_number: 1 << 48,
1204 current_local_commitment_number: 0xffff_ffff_ffff - ((((local_tx_sequence & 0xffffff) << 3*8) | (local_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1206 payment_preimages: HashMap::new(),
1207 pending_monitor_events: Vec::new(),
1208 pending_events: Vec::new(),
1210 onchain_events_waiting_threshold_conf: HashMap::new(),
1211 outputs_to_watch: HashMap::new(),
1215 lockdown_from_offchain: false,
1216 local_tx_signed: false,
1218 last_block_hash: Default::default(),
1219 secp_ctx: Secp256k1::new(),
1223 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1224 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1225 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1226 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1227 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1228 return Err(MonitorUpdateError("Previous secret did not match new one"));
1231 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1232 // events for now-revoked/fulfilled HTLCs.
1233 if let Some(txid) = self.prev_remote_commitment_txid.take() {
1234 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1239 if !self.payment_preimages.is_empty() {
1240 let cur_local_signed_commitment_tx = &self.current_local_commitment_tx;
1241 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1242 let min_idx = self.get_min_seen_secret();
1243 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1245 self.payment_preimages.retain(|&k, _| {
1246 for &(ref htlc, _, _) in cur_local_signed_commitment_tx.htlc_outputs.iter() {
1247 if k == htlc.payment_hash {
1251 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1252 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1253 if k == htlc.payment_hash {
1258 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1265 remote_hash_commitment_number.remove(&k);
1274 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1275 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1276 /// possibly future revocation/preimage information) to claim outputs where possible.
1277 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1278 pub(super) fn provide_latest_remote_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 {
1279 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1280 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1281 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1283 for &(ref htlc, _) in &htlc_outputs {
1284 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1287 let new_txid = unsigned_commitment_tx.txid();
1288 log_trace!(logger, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1289 log_trace!(logger, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1290 self.prev_remote_commitment_txid = self.current_remote_commitment_txid.take();
1291 self.current_remote_commitment_txid = Some(new_txid);
1292 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1293 self.current_remote_commitment_number = commitment_number;
1294 //TODO: Merge this into the other per-remote-transaction output storage stuff
1295 match self.their_cur_revocation_points {
1296 Some(old_points) => {
1297 if old_points.0 == commitment_number + 1 {
1298 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1299 } else if old_points.0 == commitment_number + 2 {
1300 if let Some(old_second_point) = old_points.2 {
1301 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1303 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1306 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1310 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1313 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1314 for htlc in htlc_outputs {
1315 if htlc.0.transaction_output_index.is_some() {
1319 self.remote_tx_cache.per_htlc.insert(new_txid, htlcs);
1322 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1323 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1324 /// is important that any clones of this channel monitor (including remote clones) by kept
1325 /// up-to-date as our local commitment transaction is updated.
1326 /// Panics if set_on_local_tx_csv has never been called.
1327 pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1328 if self.local_tx_signed {
1329 return Err(MonitorUpdateError("A local commitment tx has already been signed, no new local commitment txn can be sent to our counterparty"));
1331 let txid = commitment_tx.txid();
1332 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1333 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1334 let mut new_local_commitment_tx = LocalSignedTx {
1336 revocation_key: commitment_tx.local_keys.revocation_key,
1337 a_htlc_key: commitment_tx.local_keys.a_htlc_key,
1338 b_htlc_key: commitment_tx.local_keys.b_htlc_key,
1339 delayed_payment_key: commitment_tx.local_keys.a_delayed_payment_key,
1340 per_commitment_point: commitment_tx.local_keys.per_commitment_point,
1341 feerate_per_kw: commitment_tx.feerate_per_kw,
1342 htlc_outputs: htlc_outputs,
1344 // Returning a monitor error before updating tracking points means in case of using
1345 // a concurrent watchtower implementation for same channel, if this one doesn't
1346 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1347 // for which you want to spend outputs. We're NOT robust again this scenario right
1348 // now but we should consider it later.
1349 if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx) {
1350 return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1352 self.current_local_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1353 mem::swap(&mut new_local_commitment_tx, &mut self.current_local_commitment_tx);
1354 self.prev_local_signed_commitment_tx = Some(new_local_commitment_tx);
1358 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1359 /// commitment_tx_infos which contain the payment hash have been revoked.
1360 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1361 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1364 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1365 where B::Target: BroadcasterInterface,
1368 for tx in self.get_latest_local_commitment_txn(logger).iter() {
1369 broadcaster.broadcast_transaction(tx);
1371 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1374 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1377 /// panics if the given update is not the next update by update_id.
1378 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1379 where B::Target: BroadcasterInterface,
1382 if self.latest_update_id + 1 != updates.update_id {
1383 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1385 for update in updates.updates.drain(..) {
1387 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1388 if self.lockdown_from_offchain { panic!(); }
1389 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1391 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1392 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1393 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1394 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1395 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1396 self.provide_secret(idx, secret)?,
1397 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1398 self.lockdown_from_offchain = true;
1399 if should_broadcast {
1400 self.broadcast_latest_local_commitment_txn(broadcaster, logger);
1402 log_error!(logger, "You have a toxic local commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_local_commitment_txn to be informed of manual action to take");
1407 self.latest_update_id = updates.update_id;
1411 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1413 pub fn get_latest_update_id(&self) -> u64 {
1414 self.latest_update_id
1417 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1418 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1422 /// Gets a list of txids, with their output scripts (in the order they appear in the
1423 /// transaction), which we must learn about spends of via block_connected().
1424 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1425 &self.outputs_to_watch
1428 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1429 /// Generally useful when deserializing as during normal operation the return values of
1430 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1431 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1432 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1433 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1434 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1435 for (idx, output) in outputs.iter().enumerate() {
1436 res.push(((*txid).clone(), idx as u32, output));
1442 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1443 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_monitor_events().
1444 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1445 let mut ret = Vec::new();
1446 mem::swap(&mut ret, &mut self.pending_monitor_events);
1450 /// Gets the list of pending events which were generated by previous actions, clearing the list
1453 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1454 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1455 /// no internal locking in ChannelMonitors.
1456 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1457 let mut ret = Vec::new();
1458 mem::swap(&mut ret, &mut self.pending_events);
1462 /// Can only fail if idx is < get_min_seen_secret
1463 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1464 self.commitment_secrets.get_secret(idx)
1467 pub(super) fn get_min_seen_secret(&self) -> u64 {
1468 self.commitment_secrets.get_min_seen_secret()
1471 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1472 self.current_remote_commitment_number
1475 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1476 self.current_local_commitment_number
1479 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1480 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1481 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1482 /// HTLC-Success/HTLC-Timeout transactions.
1483 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1484 /// revoked remote commitment tx
1485 fn check_spend_remote_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1486 // Most secp and related errors trying to create keys means we have no hope of constructing
1487 // a spend transaction...so we return no transactions to broadcast
1488 let mut claimable_outpoints = Vec::new();
1489 let mut watch_outputs = Vec::new();
1491 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1492 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1494 macro_rules! ignore_error {
1495 ( $thing : expr ) => {
1498 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1503 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);
1504 if commitment_number >= self.get_min_seen_secret() {
1505 let secret = self.get_secret(commitment_number).unwrap();
1506 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1507 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1508 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1509 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.remote_tx_cache.remote_delayed_payment_base_key));
1511 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.remote_tx_cache.on_remote_tx_csv, &delayed_key);
1512 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1514 // First, process non-htlc outputs (to_local & to_remote)
1515 for (idx, outp) in tx.output.iter().enumerate() {
1516 if outp.script_pubkey == revokeable_p2wsh {
1517 let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv};
1518 claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.remote_tx_cache.on_remote_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
1522 // Then, try to find revoked htlc outputs
1523 if let Some(ref per_commitment_data) = per_commitment_option {
1524 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1525 if let Some(transaction_output_index) = htlc.transaction_output_index {
1526 if transaction_output_index as usize >= tx.output.len() ||
1527 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1528 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1530 let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_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_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv};
1531 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1536 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1537 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1538 // We're definitely a remote commitment transaction!
1539 log_trace!(logger, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1540 watch_outputs.append(&mut tx.output.clone());
1541 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1543 macro_rules! check_htlc_fails {
1544 ($txid: expr, $commitment_tx: expr) => {
1545 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1546 for &(ref htlc, ref source_option) in outpoints.iter() {
1547 if let &Some(ref source) = source_option {
1548 log_info!(logger, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1549 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1550 hash_map::Entry::Occupied(mut entry) => {
1551 let e = entry.get_mut();
1552 e.retain(|ref event| {
1554 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1555 return htlc_update.0 != **source
1560 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1562 hash_map::Entry::Vacant(entry) => {
1563 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1571 if let Some(ref txid) = self.current_remote_commitment_txid {
1572 check_htlc_fails!(txid, "current");
1574 if let Some(ref txid) = self.prev_remote_commitment_txid {
1575 check_htlc_fails!(txid, "remote");
1577 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1579 } else if let Some(per_commitment_data) = per_commitment_option {
1580 // While this isn't useful yet, there is a potential race where if a counterparty
1581 // revokes a state at the same time as the commitment transaction for that state is
1582 // confirmed, and the watchtower receives the block before the user, the user could
1583 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1584 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1585 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1587 watch_outputs.append(&mut tx.output.clone());
1588 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1590 log_trace!(logger, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1592 macro_rules! check_htlc_fails {
1593 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1594 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1595 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1596 if let &Some(ref source) = source_option {
1597 // Check if the HTLC is present in the commitment transaction that was
1598 // broadcast, but not if it was below the dust limit, which we should
1599 // fail backwards immediately as there is no way for us to learn the
1600 // payment_preimage.
1601 // Note that if the dust limit were allowed to change between
1602 // commitment transactions we'd want to be check whether *any*
1603 // broadcastable commitment transaction has the HTLC in it, but it
1604 // cannot currently change after channel initialization, so we don't
1606 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1607 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1611 log_trace!(logger, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1612 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1613 hash_map::Entry::Occupied(mut entry) => {
1614 let e = entry.get_mut();
1615 e.retain(|ref event| {
1617 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1618 return htlc_update.0 != **source
1623 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1625 hash_map::Entry::Vacant(entry) => {
1626 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1634 if let Some(ref txid) = self.current_remote_commitment_txid {
1635 check_htlc_fails!(txid, "current", 'current_loop);
1637 if let Some(ref txid) = self.prev_remote_commitment_txid {
1638 check_htlc_fails!(txid, "previous", 'prev_loop);
1641 if let Some(revocation_points) = self.their_cur_revocation_points {
1642 let revocation_point_option =
1643 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1644 else if let Some(point) = revocation_points.2.as_ref() {
1645 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1647 if let Some(revocation_point) = revocation_point_option {
1648 self.remote_payment_script = {
1649 // Note that the Network here is ignored as we immediately drop the address for the
1650 // script_pubkey version
1651 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1652 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1655 // Then, try to find htlc outputs
1656 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1657 if let Some(transaction_output_index) = htlc.transaction_output_index {
1658 if transaction_output_index as usize >= tx.output.len() ||
1659 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1660 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1662 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1663 let aggregable = if !htlc.offered { false } else { true };
1664 if preimage.is_some() || !htlc.offered {
1665 let witness_data = InputMaterial::RemoteHTLC { per_commitment_point: *revocation_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, preimage, htlc: htlc.clone() };
1666 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1673 (claimable_outpoints, (commitment_txid, watch_outputs))
1676 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1677 fn check_spend_remote_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<TxOut>)>) where L::Target: Logger {
1678 let htlc_txid = tx.txid();
1679 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1680 return (Vec::new(), None)
1683 macro_rules! ignore_error {
1684 ( $thing : expr ) => {
1687 Err(_) => return (Vec::new(), None)
1692 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1693 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1694 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1696 log_trace!(logger, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1697 let witness_data = InputMaterial::Revoked { per_commitment_point, remote_delayed_payment_base_key: self.remote_tx_cache.remote_delayed_payment_base_key, remote_htlc_base_key: self.remote_tx_cache.remote_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv };
1698 let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.remote_tx_cache.on_remote_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
1699 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1702 fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1703 let mut claim_requests = Vec::with_capacity(local_tx.htlc_outputs.len());
1704 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1706 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.on_local_tx_csv, &local_tx.delayed_payment_key);
1707 let broadcasted_local_revokable_script = Some((redeemscript.to_v0_p2wsh(), local_tx.per_commitment_point.clone(), local_tx.revocation_key.clone()));
1709 for &(ref htlc, _, _) in local_tx.htlc_outputs.iter() {
1710 if let Some(transaction_output_index) = htlc.transaction_output_index {
1711 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: local_tx.txid, vout: transaction_output_index as u32 },
1712 witness_data: InputMaterial::LocalHTLC {
1713 preimage: if !htlc.offered {
1714 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1715 Some(preimage.clone())
1717 // We can't build an HTLC-Success transaction without the preimage
1721 amount: htlc.amount_msat,
1723 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1727 (claim_requests, watch_outputs, broadcasted_local_revokable_script)
1730 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1731 /// revoked using data in local_claimable_outpoints.
1732 /// Should not be used if check_spend_revoked_transaction succeeds.
1733 fn check_spend_local_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1734 let commitment_txid = tx.txid();
1735 let mut claim_requests = Vec::new();
1736 let mut watch_outputs = Vec::new();
1738 macro_rules! wait_threshold_conf {
1739 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1740 log_trace!(logger, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1741 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1742 hash_map::Entry::Occupied(mut entry) => {
1743 let e = entry.get_mut();
1744 e.retain(|ref event| {
1746 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1747 return htlc_update.0 != $source
1752 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1754 hash_map::Entry::Vacant(entry) => {
1755 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1761 macro_rules! append_onchain_update {
1762 ($updates: expr) => {
1763 claim_requests = $updates.0;
1764 watch_outputs.append(&mut $updates.1);
1765 self.broadcasted_local_revokable_script = $updates.2;
1769 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1770 let mut is_local_tx = false;
1772 if self.current_local_commitment_tx.txid == commitment_txid {
1774 log_trace!(logger, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1775 let mut res = self.broadcast_by_local_state(tx, &self.current_local_commitment_tx);
1776 append_onchain_update!(res);
1777 } else if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1778 if local_tx.txid == commitment_txid {
1780 log_trace!(logger, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1781 let mut res = self.broadcast_by_local_state(tx, local_tx);
1782 append_onchain_update!(res);
1786 macro_rules! fail_dust_htlcs_after_threshold_conf {
1787 ($local_tx: expr) => {
1788 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1789 if htlc.transaction_output_index.is_none() {
1790 if let &Some(ref source) = source {
1791 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1799 fail_dust_htlcs_after_threshold_conf!(self.current_local_commitment_tx);
1800 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1801 fail_dust_htlcs_after_threshold_conf!(local_tx);
1805 (claim_requests, (commitment_txid, watch_outputs))
1808 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1809 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1810 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1811 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1812 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1813 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1814 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1815 /// out-of-band the other node operator to coordinate with him if option is available to you.
1816 /// In any-case, choice is up to the user.
1817 pub fn get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1818 log_trace!(logger, "Getting signed latest local commitment transaction!");
1819 self.local_tx_signed = true;
1820 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1821 let txid = commitment_tx.txid();
1822 let mut res = vec![commitment_tx];
1823 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1824 if let Some(vout) = htlc.0.transaction_output_index {
1825 let preimage = if !htlc.0.offered {
1826 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1827 // We can't build an HTLC-Success transaction without the preimage
1831 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1832 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1837 // 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.
1838 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1844 /// Unsafe test-only version of get_latest_local_commitment_txn used by our test framework
1845 /// to bypass LocalCommitmentTransaction state update lockdown after signature and generate
1846 /// revoked commitment transaction.
1847 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1848 pub fn unsafe_get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1849 log_trace!(logger, "Getting signed copy of latest local commitment transaction!");
1850 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_local_tx(&self.funding_redeemscript) {
1851 let txid = commitment_tx.txid();
1852 let mut res = vec![commitment_tx];
1853 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1854 if let Some(vout) = htlc.0.transaction_output_index {
1855 let preimage = if !htlc.0.offered {
1856 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1857 // We can't build an HTLC-Success transaction without the preimage
1861 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1862 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1872 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1873 /// ChainListener::block_connected.
1874 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1875 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1877 fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<TxOut>)>
1878 where B::Target: BroadcasterInterface,
1879 F::Target: FeeEstimator,
1882 for tx in txn_matched {
1883 let mut output_val = 0;
1884 for out in tx.output.iter() {
1885 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1886 output_val += out.value;
1887 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1891 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1892 let mut watch_outputs = Vec::new();
1893 let mut claimable_outpoints = Vec::new();
1894 for tx in txn_matched {
1895 if tx.input.len() == 1 {
1896 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1897 // commitment transactions and HTLC transactions will all only ever have one input,
1898 // which is an easy way to filter out any potential non-matching txn for lazy
1900 let prevout = &tx.input[0].previous_output;
1901 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1902 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1903 let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height, &logger);
1904 if !new_outputs.1.is_empty() {
1905 watch_outputs.push(new_outputs);
1907 if new_outpoints.is_empty() {
1908 let (mut new_outpoints, new_outputs) = self.check_spend_local_transaction(&tx, height, &logger);
1909 if !new_outputs.1.is_empty() {
1910 watch_outputs.push(new_outputs);
1912 claimable_outpoints.append(&mut new_outpoints);
1914 claimable_outpoints.append(&mut new_outpoints);
1917 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1918 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height, &logger);
1919 claimable_outpoints.append(&mut new_outpoints);
1920 if let Some(new_outputs) = new_outputs_option {
1921 watch_outputs.push(new_outputs);
1926 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1927 // can also be resolved in a few other ways which can have more than one output. Thus,
1928 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1929 self.is_resolving_htlc_output(&tx, height, &logger);
1931 self.is_paying_spendable_output(&tx, height, &logger);
1933 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1934 if should_broadcast {
1935 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() }});
1937 if should_broadcast {
1938 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1939 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1940 self.local_tx_signed = true;
1941 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_local_state(&commitment_tx, &self.current_local_commitment_tx);
1942 if !new_outputs.is_empty() {
1943 watch_outputs.push((self.current_local_commitment_tx.txid.clone(), new_outputs));
1945 claimable_outpoints.append(&mut new_outpoints);
1948 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1951 OnchainEvent::HTLCUpdate { htlc_update } => {
1952 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1953 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1954 payment_hash: htlc_update.1,
1955 payment_preimage: None,
1956 source: htlc_update.0,
1959 OnchainEvent::MaturingOutput { descriptor } => {
1960 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1961 self.pending_events.push(Event::SpendableOutputs {
1962 outputs: vec![descriptor]
1969 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1971 self.last_block_hash = block_hash.clone();
1972 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1973 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1979 fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)
1980 where B::Target: BroadcasterInterface,
1981 F::Target: FeeEstimator,
1984 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1985 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1987 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1988 //- maturing spendable output has transaction paying us has been disconnected
1991 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1993 self.last_block_hash = block_hash.clone();
1996 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
1997 // We need to consider all HTLCs which are:
1998 // * in any unrevoked remote commitment transaction, as they could broadcast said
1999 // transactions and we'd end up in a race, or
2000 // * are in our latest local commitment transaction, as this is the thing we will
2001 // broadcast if we go on-chain.
2002 // Note that we consider HTLCs which were below dust threshold here - while they don't
2003 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2004 // to the source, and if we don't fail the channel we will have to ensure that the next
2005 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2006 // easier to just fail the channel as this case should be rare enough anyway.
2007 macro_rules! scan_commitment {
2008 ($htlcs: expr, $local_tx: expr) => {
2009 for ref htlc in $htlcs {
2010 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2011 // chain with enough room to claim the HTLC without our counterparty being able to
2012 // time out the HTLC first.
2013 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2014 // concern is being able to claim the corresponding inbound HTLC (on another
2015 // channel) before it expires. In fact, we don't even really care if our
2016 // counterparty here claims such an outbound HTLC after it expired as long as we
2017 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2018 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2019 // we give ourselves a few blocks of headroom after expiration before going
2020 // on-chain for an expired HTLC.
2021 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2022 // from us until we've reached the point where we go on-chain with the
2023 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2024 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2025 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2026 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2027 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2028 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2029 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2030 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2031 // The final, above, condition is checked for statically in channelmanager
2032 // with CHECK_CLTV_EXPIRY_SANITY_2.
2033 let htlc_outbound = $local_tx == htlc.offered;
2034 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2035 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2036 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2043 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2045 if let Some(ref txid) = self.current_remote_commitment_txid {
2046 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2047 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2050 if let Some(ref txid) = self.prev_remote_commitment_txid {
2051 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2052 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2059 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2060 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2061 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2062 'outer_loop: for input in &tx.input {
2063 let mut payment_data = None;
2064 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2065 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2066 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2067 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2069 macro_rules! log_claim {
2070 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2071 // We found the output in question, but aren't failing it backwards
2072 // as we have no corresponding source and no valid remote commitment txid
2073 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2074 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2075 let outbound_htlc = $local_tx == $htlc.offered;
2076 if ($local_tx && revocation_sig_claim) ||
2077 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2078 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2079 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2080 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2081 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2083 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2084 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2085 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2086 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2091 macro_rules! check_htlc_valid_remote {
2092 ($remote_txid: expr, $htlc_output: expr) => {
2093 if let Some(txid) = $remote_txid {
2094 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2095 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2096 if let &Some(ref source) = pending_source {
2097 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2098 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2107 macro_rules! scan_commitment {
2108 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2109 for (ref htlc_output, source_option) in $htlcs {
2110 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2111 if let Some(ref source) = source_option {
2112 log_claim!($tx_info, $local_tx, htlc_output, true);
2113 // We have a resolution of an HTLC either from one of our latest
2114 // local commitment transactions or an unrevoked remote commitment
2115 // transaction. This implies we either learned a preimage, the HTLC
2116 // has timed out, or we screwed up. In any case, we should now
2117 // resolve the source HTLC with the original sender.
2118 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2119 } else if !$local_tx {
2120 check_htlc_valid_remote!(self.current_remote_commitment_txid, htlc_output);
2121 if payment_data.is_none() {
2122 check_htlc_valid_remote!(self.prev_remote_commitment_txid, htlc_output);
2125 if payment_data.is_none() {
2126 log_claim!($tx_info, $local_tx, htlc_output, false);
2127 continue 'outer_loop;
2134 if input.previous_output.txid == self.current_local_commitment_tx.txid {
2135 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2136 "our latest local commitment tx", true);
2138 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2139 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2140 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2141 "our previous local commitment tx", true);
2144 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2145 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2146 "remote commitment tx", false);
2149 // Check that scan_commitment, above, decided there is some source worth relaying an
2150 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2151 if let Some((source, payment_hash)) = payment_data {
2152 let mut payment_preimage = PaymentPreimage([0; 32]);
2153 if accepted_preimage_claim {
2154 if !self.pending_monitor_events.iter().any(
2155 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2156 payment_preimage.0.copy_from_slice(&input.witness[3]);
2157 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2159 payment_preimage: Some(payment_preimage),
2163 } else if offered_preimage_claim {
2164 if !self.pending_monitor_events.iter().any(
2165 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2166 upd.source == source
2168 payment_preimage.0.copy_from_slice(&input.witness[1]);
2169 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2171 payment_preimage: Some(payment_preimage),
2176 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);
2177 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2178 hash_map::Entry::Occupied(mut entry) => {
2179 let e = entry.get_mut();
2180 e.retain(|ref event| {
2182 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2183 return htlc_update.0 != source
2188 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2190 hash_map::Entry::Vacant(entry) => {
2191 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2199 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2200 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2201 let mut spendable_output = None;
2202 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2203 if i > ::std::u16::MAX as usize {
2204 // While it is possible that an output exists on chain which is greater than the
2205 // 2^16th output in a given transaction, this is only possible if the output is not
2206 // in a lightning transaction and was instead placed there by some third party who
2207 // wishes to give us money for no reason.
2208 // Namely, any lightning transactions which we pre-sign will never have anywhere
2209 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2210 // scripts are not longer than one byte in length and because they are inherently
2211 // non-standard due to their size.
2212 // Thus, it is completely safe to ignore such outputs, and while it may result in
2213 // us ignoring non-lightning fund to us, that is only possible if someone fills
2214 // nearly a full block with garbage just to hit this case.
2217 if outp.script_pubkey == self.destination_script {
2218 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2219 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2220 output: outp.clone(),
2223 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2224 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2225 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2226 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2227 per_commitment_point: broadcasted_local_revokable_script.1,
2228 to_self_delay: self.on_local_tx_csv,
2229 output: outp.clone(),
2230 key_derivation_params: self.keys.key_derivation_params(),
2231 remote_revocation_pubkey: broadcasted_local_revokable_script.2.clone(),
2235 } else if self.remote_payment_script == outp.script_pubkey {
2236 spendable_output = Some(SpendableOutputDescriptor::StaticOutputRemotePayment {
2237 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2238 output: outp.clone(),
2239 key_derivation_params: self.keys.key_derivation_params(),
2242 } else if outp.script_pubkey == self.shutdown_script {
2243 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2244 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2245 output: outp.clone(),
2249 if let Some(spendable_output) = spendable_output {
2250 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2251 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2252 hash_map::Entry::Occupied(mut entry) => {
2253 let e = entry.get_mut();
2254 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2256 hash_map::Entry::Vacant(entry) => {
2257 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2264 const MAX_ALLOC_SIZE: usize = 64*1024;
2266 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2267 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2268 macro_rules! unwrap_obj {
2272 Err(_) => return Err(DecodeError::InvalidValue),
2277 let _ver: u8 = Readable::read(reader)?;
2278 let min_ver: u8 = Readable::read(reader)?;
2279 if min_ver > SERIALIZATION_VERSION {
2280 return Err(DecodeError::UnknownVersion);
2283 let latest_update_id: u64 = Readable::read(reader)?;
2284 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2286 let destination_script = Readable::read(reader)?;
2287 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2289 let revokable_address = Readable::read(reader)?;
2290 let per_commitment_point = Readable::read(reader)?;
2291 let revokable_script = Readable::read(reader)?;
2292 Some((revokable_address, per_commitment_point, revokable_script))
2295 _ => return Err(DecodeError::InvalidValue),
2297 let remote_payment_script = Readable::read(reader)?;
2298 let shutdown_script = Readable::read(reader)?;
2300 let keys = Readable::read(reader)?;
2301 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2302 // barely-init'd ChannelMonitors that we can't do anything with.
2303 let outpoint = OutPoint {
2304 txid: Readable::read(reader)?,
2305 index: Readable::read(reader)?,
2307 let funding_info = (outpoint, Readable::read(reader)?);
2308 let current_remote_commitment_txid = Readable::read(reader)?;
2309 let prev_remote_commitment_txid = Readable::read(reader)?;
2311 let remote_tx_cache = Readable::read(reader)?;
2312 let funding_redeemscript = Readable::read(reader)?;
2313 let channel_value_satoshis = Readable::read(reader)?;
2315 let their_cur_revocation_points = {
2316 let first_idx = <U48 as Readable>::read(reader)?.0;
2320 let first_point = Readable::read(reader)?;
2321 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2322 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2323 Some((first_idx, first_point, None))
2325 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2330 let on_local_tx_csv: u16 = Readable::read(reader)?;
2332 let commitment_secrets = Readable::read(reader)?;
2334 macro_rules! read_htlc_in_commitment {
2337 let offered: bool = Readable::read(reader)?;
2338 let amount_msat: u64 = Readable::read(reader)?;
2339 let cltv_expiry: u32 = Readable::read(reader)?;
2340 let payment_hash: PaymentHash = Readable::read(reader)?;
2341 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2343 HTLCOutputInCommitment {
2344 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2350 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2351 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2352 for _ in 0..remote_claimable_outpoints_len {
2353 let txid: Txid = Readable::read(reader)?;
2354 let htlcs_count: u64 = Readable::read(reader)?;
2355 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2356 for _ in 0..htlcs_count {
2357 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2359 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2360 return Err(DecodeError::InvalidValue);
2364 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2365 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2366 for _ in 0..remote_commitment_txn_on_chain_len {
2367 let txid: Txid = Readable::read(reader)?;
2368 let commitment_number = <U48 as Readable>::read(reader)?.0;
2369 let outputs_count = <u64 as Readable>::read(reader)?;
2370 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2371 for _ in 0..outputs_count {
2372 outputs.push(Readable::read(reader)?);
2374 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2375 return Err(DecodeError::InvalidValue);
2379 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2380 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2381 for _ in 0..remote_hash_commitment_number_len {
2382 let payment_hash: PaymentHash = Readable::read(reader)?;
2383 let commitment_number = <U48 as Readable>::read(reader)?.0;
2384 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2385 return Err(DecodeError::InvalidValue);
2389 macro_rules! read_local_tx {
2392 let txid = Readable::read(reader)?;
2393 let revocation_key = Readable::read(reader)?;
2394 let a_htlc_key = Readable::read(reader)?;
2395 let b_htlc_key = Readable::read(reader)?;
2396 let delayed_payment_key = Readable::read(reader)?;
2397 let per_commitment_point = Readable::read(reader)?;
2398 let feerate_per_kw: u32 = Readable::read(reader)?;
2400 let htlcs_len: u64 = Readable::read(reader)?;
2401 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2402 for _ in 0..htlcs_len {
2403 let htlc = read_htlc_in_commitment!();
2404 let sigs = match <u8 as Readable>::read(reader)? {
2406 1 => Some(Readable::read(reader)?),
2407 _ => return Err(DecodeError::InvalidValue),
2409 htlcs.push((htlc, sigs, Readable::read(reader)?));
2414 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2421 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2424 Some(read_local_tx!())
2426 _ => return Err(DecodeError::InvalidValue),
2428 let current_local_commitment_tx = read_local_tx!();
2430 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2431 let current_local_commitment_number = <U48 as Readable>::read(reader)?.0;
2433 let payment_preimages_len: u64 = Readable::read(reader)?;
2434 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2435 for _ in 0..payment_preimages_len {
2436 let preimage: PaymentPreimage = Readable::read(reader)?;
2437 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2438 if let Some(_) = payment_preimages.insert(hash, preimage) {
2439 return Err(DecodeError::InvalidValue);
2443 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2444 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2445 for _ in 0..pending_monitor_events_len {
2446 let ev = match <u8 as Readable>::read(reader)? {
2447 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2448 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2449 _ => return Err(DecodeError::InvalidValue)
2451 pending_monitor_events.push(ev);
2454 let pending_events_len: u64 = Readable::read(reader)?;
2455 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2456 for _ in 0..pending_events_len {
2457 if let Some(event) = MaybeReadable::read(reader)? {
2458 pending_events.push(event);
2462 let last_block_hash: BlockHash = Readable::read(reader)?;
2464 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2465 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2466 for _ in 0..waiting_threshold_conf_len {
2467 let height_target = Readable::read(reader)?;
2468 let events_len: u64 = Readable::read(reader)?;
2469 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2470 for _ in 0..events_len {
2471 let ev = match <u8 as Readable>::read(reader)? {
2473 let htlc_source = Readable::read(reader)?;
2474 let hash = Readable::read(reader)?;
2475 OnchainEvent::HTLCUpdate {
2476 htlc_update: (htlc_source, hash)
2480 let descriptor = Readable::read(reader)?;
2481 OnchainEvent::MaturingOutput {
2485 _ => return Err(DecodeError::InvalidValue),
2489 onchain_events_waiting_threshold_conf.insert(height_target, events);
2492 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2493 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>>())));
2494 for _ in 0..outputs_to_watch_len {
2495 let txid = Readable::read(reader)?;
2496 let outputs_len: u64 = Readable::read(reader)?;
2497 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2498 for _ in 0..outputs_len {
2499 outputs.push(Readable::read(reader)?);
2501 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2502 return Err(DecodeError::InvalidValue);
2505 let onchain_tx_handler = Readable::read(reader)?;
2507 let lockdown_from_offchain = Readable::read(reader)?;
2508 let local_tx_signed = Readable::read(reader)?;
2510 Ok((last_block_hash.clone(), ChannelMonitor {
2512 commitment_transaction_number_obscure_factor,
2515 broadcasted_local_revokable_script,
2516 remote_payment_script,
2521 current_remote_commitment_txid,
2522 prev_remote_commitment_txid,
2525 funding_redeemscript,
2526 channel_value_satoshis,
2527 their_cur_revocation_points,
2532 remote_claimable_outpoints,
2533 remote_commitment_txn_on_chain,
2534 remote_hash_commitment_number,
2536 prev_local_signed_commitment_tx,
2537 current_local_commitment_tx,
2538 current_remote_commitment_number,
2539 current_local_commitment_number,
2542 pending_monitor_events,
2545 onchain_events_waiting_threshold_conf,
2550 lockdown_from_offchain,
2554 secp_ctx: Secp256k1::new(),
2561 use bitcoin::blockdata::script::{Script, Builder};
2562 use bitcoin::blockdata::opcodes;
2563 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2564 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2565 use bitcoin::util::bip143;
2566 use bitcoin::hashes::Hash;
2567 use bitcoin::hashes::sha256::Hash as Sha256;
2568 use bitcoin::hashes::hex::FromHex;
2569 use bitcoin::hash_types::Txid;
2571 use chain::transaction::OutPoint;
2572 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2573 use ln::channelmonitor::ChannelMonitor;
2574 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2576 use ln::chan_utils::{HTLCOutputInCommitment, LocalCommitmentTransaction};
2577 use util::test_utils::TestLogger;
2578 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2579 use bitcoin::secp256k1::Secp256k1;
2581 use chain::keysinterface::InMemoryChannelKeys;
2584 fn test_prune_preimages() {
2585 let secp_ctx = Secp256k1::new();
2586 let logger = Arc::new(TestLogger::new());
2588 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2589 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2591 let mut preimages = Vec::new();
2594 let preimage = PaymentPreimage([i; 32]);
2595 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2596 preimages.push((preimage, hash));
2600 macro_rules! preimages_slice_to_htlc_outputs {
2601 ($preimages_slice: expr) => {
2603 let mut res = Vec::new();
2604 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2605 res.push((HTLCOutputInCommitment {
2609 payment_hash: preimage.1.clone(),
2610 transaction_output_index: Some(idx as u32),
2617 macro_rules! preimages_to_local_htlcs {
2618 ($preimages_slice: expr) => {
2620 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2621 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2627 macro_rules! test_preimages_exist {
2628 ($preimages_slice: expr, $monitor: expr) => {
2629 for preimage in $preimages_slice {
2630 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2635 let keys = InMemoryChannelKeys::new(
2637 SecretKey::from_slice(&[41; 32]).unwrap(),
2638 SecretKey::from_slice(&[41; 32]).unwrap(),
2639 SecretKey::from_slice(&[41; 32]).unwrap(),
2640 SecretKey::from_slice(&[41; 32]).unwrap(),
2641 SecretKey::from_slice(&[41; 32]).unwrap(),
2647 // Prune with one old state and a local commitment tx holding a few overlaps with the
2649 let mut monitor = ChannelMonitor::new(keys,
2650 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2651 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2652 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2653 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2654 10, Script::new(), 46, 0, LocalCommitmentTransaction::dummy());
2656 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2657 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2658 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2659 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2660 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2661 for &(ref preimage, ref hash) in preimages.iter() {
2662 monitor.provide_payment_preimage(hash, preimage);
2665 // Now provide a secret, pruning preimages 10-15
2666 let mut secret = [0; 32];
2667 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2668 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2669 assert_eq!(monitor.payment_preimages.len(), 15);
2670 test_preimages_exist!(&preimages[0..10], monitor);
2671 test_preimages_exist!(&preimages[15..20], monitor);
2673 // Now provide a further secret, pruning preimages 15-17
2674 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2675 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2676 assert_eq!(monitor.payment_preimages.len(), 13);
2677 test_preimages_exist!(&preimages[0..10], monitor);
2678 test_preimages_exist!(&preimages[17..20], monitor);
2680 // Now update local commitment tx info, pruning only element 18 as we still care about the
2681 // previous commitment tx's preimages too
2682 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2683 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2684 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2685 assert_eq!(monitor.payment_preimages.len(), 12);
2686 test_preimages_exist!(&preimages[0..10], monitor);
2687 test_preimages_exist!(&preimages[18..20], monitor);
2689 // But if we do it again, we'll prune 5-10
2690 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2691 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2692 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2693 assert_eq!(monitor.payment_preimages.len(), 5);
2694 test_preimages_exist!(&preimages[0..5], monitor);
2698 fn test_claim_txn_weight_computation() {
2699 // We test Claim txn weight, knowing that we want expected weigth and
2700 // not actual case to avoid sigs and time-lock delays hell variances.
2702 let secp_ctx = Secp256k1::new();
2703 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2704 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2705 let mut sum_actual_sigs = 0;
2707 macro_rules! sign_input {
2708 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2709 let htlc = HTLCOutputInCommitment {
2710 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2712 cltv_expiry: 2 << 16,
2713 payment_hash: PaymentHash([1; 32]),
2714 transaction_output_index: Some($idx),
2716 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2717 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2718 let sig = secp_ctx.sign(&sighash, &privkey);
2719 $input.witness.push(sig.serialize_der().to_vec());
2720 $input.witness[0].push(SigHashType::All as u8);
2721 sum_actual_sigs += $input.witness[0].len();
2722 if *$input_type == InputDescriptors::RevokedOutput {
2723 $input.witness.push(vec!(1));
2724 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2725 $input.witness.push(pubkey.clone().serialize().to_vec());
2726 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2727 $input.witness.push(vec![0]);
2729 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2731 $input.witness.push(redeem_script.into_bytes());
2732 println!("witness[0] {}", $input.witness[0].len());
2733 println!("witness[1] {}", $input.witness[1].len());
2734 println!("witness[2] {}", $input.witness[2].len());
2738 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2739 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2741 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2742 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2744 claim_tx.input.push(TxIn {
2745 previous_output: BitcoinOutPoint {
2749 script_sig: Script::new(),
2750 sequence: 0xfffffffd,
2751 witness: Vec::new(),
2754 claim_tx.output.push(TxOut {
2755 script_pubkey: script_pubkey.clone(),
2758 let base_weight = claim_tx.get_weight();
2759 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2760 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2761 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2762 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2764 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));
2766 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2767 claim_tx.input.clear();
2768 sum_actual_sigs = 0;
2770 claim_tx.input.push(TxIn {
2771 previous_output: BitcoinOutPoint {
2775 script_sig: Script::new(),
2776 sequence: 0xfffffffd,
2777 witness: Vec::new(),
2780 let base_weight = claim_tx.get_weight();
2781 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2782 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2783 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2784 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2786 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));
2788 // Justice tx with 1 revoked HTLC-Success tx output
2789 claim_tx.input.clear();
2790 sum_actual_sigs = 0;
2791 claim_tx.input.push(TxIn {
2792 previous_output: BitcoinOutPoint {
2796 script_sig: Script::new(),
2797 sequence: 0xfffffffd,
2798 witness: Vec::new(),
2800 let base_weight = claim_tx.get_weight();
2801 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2802 let inputs_des = vec![InputDescriptors::RevokedOutput];
2803 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2804 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2806 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));
2809 // Further testing is done in the ChannelManager integration tests.