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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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;
29 use bitcoin::util::hash::BitcoinHash;
31 use bitcoin::hashes::Hash;
32 use bitcoin::hashes::sha256::Hash as Sha256;
33 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
35 use bitcoin::secp256k1::{Secp256k1,Signature};
36 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
37 use bitcoin::secp256k1;
39 use ln::msgs::DecodeError;
41 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
42 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
43 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
44 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator};
45 use chain::transaction::OutPoint;
46 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
47 use util::logger::Logger;
48 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
49 use util::{byte_utils, events};
51 use std::collections::{HashMap, hash_map};
53 use std::{hash,cmp, mem};
56 /// An update generated by the underlying Channel itself which contains some new information the
57 /// ChannelMonitor should be made aware of.
58 #[cfg_attr(test, derive(PartialEq))]
61 pub struct ChannelMonitorUpdate {
62 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
63 /// The sequence number of this update. Updates *must* be replayed in-order according to this
64 /// sequence number (and updates may panic if they are not). The update_id values are strictly
65 /// increasing and increase by one for each new update.
67 /// This sequence number is also used to track up to which points updates which returned
68 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
69 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
73 impl Writeable for ChannelMonitorUpdate {
74 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
75 self.update_id.write(w)?;
76 (self.updates.len() as u64).write(w)?;
77 for update_step in self.updates.iter() {
78 update_step.write(w)?;
83 impl Readable for ChannelMonitorUpdate {
84 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
85 let update_id: u64 = Readable::read(r)?;
86 let len: u64 = Readable::read(r)?;
87 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
89 updates.push(Readable::read(r)?);
91 Ok(Self { update_id, updates })
95 /// An error enum representing a failure to persist a channel monitor update.
97 pub enum ChannelMonitorUpdateErr {
98 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
99 /// our state failed, but is expected to succeed at some point in the future).
101 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
102 /// submitting new commitment transactions to the remote party. Once the update(s) which failed
103 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
104 /// restore the channel to an operational state.
106 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
107 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
108 /// writing out the latest ChannelManager state.
110 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
111 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
112 /// to claim it on this channel) and those updates must be applied wherever they can be. At
113 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
114 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
115 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
118 /// Note that even if updates made after TemporaryFailure succeed you must still call
119 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
122 /// Note that the update being processed here will not be replayed for you when you call
123 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
124 /// with the persisted ChannelMonitor on your own local disk prior to returning a
125 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
126 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
129 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
130 /// remote location (with local copies persisted immediately), it is anticipated that all
131 /// updates will return TemporaryFailure until the remote copies could be updated.
133 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
134 /// different watchtower and cannot update with all watchtowers that were previously informed
135 /// of this channel). This will force-close the channel in question (which will generate one
136 /// final ChannelMonitorUpdate which must be delivered to at least one ChannelMonitor copy).
138 /// Should also be used to indicate a failure to update the local persisted copy of the channel
143 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
144 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
145 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
147 /// Contains a human-readable error message.
149 pub struct MonitorUpdateError(pub &'static str);
151 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
152 /// forward channel and from which info are needed to update HTLC in a backward channel.
153 #[derive(Clone, PartialEq)]
154 pub struct HTLCUpdate {
155 pub(super) payment_hash: PaymentHash,
156 pub(super) payment_preimage: Option<PaymentPreimage>,
157 pub(super) source: HTLCSource
159 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
161 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
162 /// watchtower or watch our own channels.
164 /// Note that you must provide your own key by which to refer to channels.
166 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
167 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
168 /// index by a PublicKey which is required to sign any updates.
170 /// If you're using this for local monitoring of your own channels, you probably want to use
171 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
172 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref>
173 where T::Target: BroadcasterInterface,
174 F::Target: FeeEstimator,
176 C::Target: ChainWatchInterface,
179 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
186 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>
187 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
188 where T::Target: BroadcasterInterface,
189 F::Target: FeeEstimator,
191 C::Target: ChainWatchInterface,
193 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[usize]) {
194 let block_hash = header.bitcoin_hash();
196 let mut monitors = self.monitors.lock().unwrap();
197 for monitor in monitors.values_mut() {
198 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
200 for (ref txid, ref outputs) in txn_outputs {
201 for (idx, output) in outputs.iter().enumerate() {
202 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
209 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
210 let block_hash = header.bitcoin_hash();
211 let mut monitors = self.monitors.lock().unwrap();
212 for monitor in monitors.values_mut() {
213 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
218 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>
219 where T::Target: BroadcasterInterface,
220 F::Target: FeeEstimator,
222 C::Target: ChainWatchInterface,
224 /// Creates a new object which can be used to monitor several channels given the chain
225 /// interface with which to register to receive notifications.
226 pub fn new(chain_monitor: C, broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C> {
227 let res = SimpleManyChannelMonitor {
228 monitors: Mutex::new(HashMap::new()),
232 fee_estimator: feeest,
238 /// Adds or updates the monitor which monitors the channel referred to by the given key.
239 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
240 let mut monitors = self.monitors.lock().unwrap();
241 let entry = match monitors.entry(key) {
242 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
243 hash_map::Entry::Vacant(e) => e,
246 let funding_txo = monitor.get_funding_txo();
247 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
248 self.chain_monitor.install_watch_tx(&funding_txo.0.txid, &funding_txo.1);
249 self.chain_monitor.install_watch_outpoint((funding_txo.0.txid, funding_txo.0.index as u32), &funding_txo.1);
250 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
251 for (idx, script) in outputs.iter().enumerate() {
252 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
256 entry.insert(monitor);
260 /// Updates the monitor which monitors the channel referred to by the given key.
261 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
262 let mut monitors = self.monitors.lock().unwrap();
263 match monitors.get_mut(&key) {
264 Some(orig_monitor) => {
265 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
266 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
268 None => Err(MonitorUpdateError("No such monitor registered"))
273 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>
274 where T::Target: BroadcasterInterface,
275 F::Target: FeeEstimator,
277 C::Target: ChainWatchInterface,
279 type Keys = ChanSigner;
281 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
282 match self.add_monitor_by_key(funding_txo, monitor) {
284 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
288 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
289 match self.update_monitor_by_key(funding_txo, update) {
291 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
295 #[cfg(any(test, feature = "fuzztarget"))]
296 fn get_monitor_would_broadcast(&self, funding_txo: &OutPoint, height: u32) -> bool {
297 self.monitors.lock().unwrap().get(funding_txo).unwrap().would_broadcast_at_height(height, &self.logger)
300 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {
301 let mut pending_htlcs_updated = Vec::new();
302 for chan in self.monitors.lock().unwrap().values_mut() {
303 pending_htlcs_updated.append(&mut chan.get_and_clear_pending_htlcs_updated());
305 pending_htlcs_updated
309 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>
310 where T::Target: BroadcasterInterface,
311 F::Target: FeeEstimator,
313 C::Target: ChainWatchInterface,
315 fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
316 let mut pending_events = Vec::new();
317 for chan in self.monitors.lock().unwrap().values_mut() {
318 pending_events.append(&mut chan.get_and_clear_pending_events());
324 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
325 /// instead claiming it in its own individual transaction.
326 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
327 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
328 /// HTLC-Success transaction.
329 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
330 /// transaction confirmed (and we use it in a few more, equivalent, places).
331 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
332 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
333 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
334 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
335 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
336 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
337 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
338 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
339 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
340 /// accurate block height.
341 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
342 /// with at worst this delay, so we are not only using this value as a mercy for them but also
343 /// us as a safeguard to delay with enough time.
344 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
345 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
346 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
347 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
348 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
349 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
350 /// keeping bumping another claim tx to solve the outpoint.
351 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
352 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
353 /// refuse to accept a new HTLC.
355 /// This is used for a few separate purposes:
356 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
357 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
359 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
360 /// condition with the above), we will fail this HTLC without telling the user we received it,
361 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
362 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
364 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
365 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
367 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
368 /// in a race condition between the user connecting a block (which would fail it) and the user
369 /// providing us the preimage (which would claim it).
371 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
372 /// end up force-closing the channel on us to claim it.
373 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
375 #[derive(Clone, PartialEq)]
376 struct LocalSignedTx {
377 /// txid of the transaction in tx, just used to make comparison faster
379 revocation_key: PublicKey,
380 a_htlc_key: PublicKey,
381 b_htlc_key: PublicKey,
382 delayed_payment_key: PublicKey,
383 per_commitment_point: PublicKey,
385 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
388 /// We use this to track remote commitment transactions and htlcs outputs and
389 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
391 struct RemoteCommitmentTransaction {
392 remote_delayed_payment_base_key: PublicKey,
393 remote_htlc_base_key: PublicKey,
394 on_remote_tx_csv: u16,
395 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
398 impl Writeable for RemoteCommitmentTransaction {
399 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
400 self.remote_delayed_payment_base_key.write(w)?;
401 self.remote_htlc_base_key.write(w)?;
402 w.write_all(&byte_utils::be16_to_array(self.on_remote_tx_csv))?;
403 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
404 for (ref txid, ref htlcs) in self.per_htlc.iter() {
405 w.write_all(&txid[..])?;
406 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
407 for &ref htlc in htlcs.iter() {
414 impl Readable for RemoteCommitmentTransaction {
415 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
416 let remote_commitment_transaction = {
417 let remote_delayed_payment_base_key = Readable::read(r)?;
418 let remote_htlc_base_key = Readable::read(r)?;
419 let on_remote_tx_csv: u16 = Readable::read(r)?;
420 let per_htlc_len: u64 = Readable::read(r)?;
421 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
422 for _ in 0..per_htlc_len {
423 let txid: Txid = Readable::read(r)?;
424 let htlcs_count: u64 = Readable::read(r)?;
425 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
426 for _ in 0..htlcs_count {
427 let htlc = Readable::read(r)?;
430 if let Some(_) = per_htlc.insert(txid, htlcs) {
431 return Err(DecodeError::InvalidValue);
434 RemoteCommitmentTransaction {
435 remote_delayed_payment_base_key,
436 remote_htlc_base_key,
441 Ok(remote_commitment_transaction)
445 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
446 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
447 /// a new bumped one in case of lenghty confirmation delay
448 #[derive(Clone, PartialEq)]
449 pub(crate) enum InputMaterial {
451 per_commitment_point: PublicKey,
452 remote_delayed_payment_base_key: PublicKey,
453 remote_htlc_base_key: PublicKey,
454 per_commitment_key: SecretKey,
455 input_descriptor: InputDescriptors,
457 htlc: Option<HTLCOutputInCommitment>,
458 on_remote_tx_csv: u16,
461 per_commitment_point: PublicKey,
462 remote_delayed_payment_base_key: PublicKey,
463 remote_htlc_base_key: PublicKey,
464 preimage: Option<PaymentPreimage>,
465 htlc: HTLCOutputInCommitment
468 preimage: Option<PaymentPreimage>,
472 funding_redeemscript: Script,
476 impl Writeable for InputMaterial {
477 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
479 &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} => {
480 writer.write_all(&[0; 1])?;
481 per_commitment_point.write(writer)?;
482 remote_delayed_payment_base_key.write(writer)?;
483 remote_htlc_base_key.write(writer)?;
484 writer.write_all(&per_commitment_key[..])?;
485 input_descriptor.write(writer)?;
486 writer.write_all(&byte_utils::be64_to_array(*amount))?;
488 on_remote_tx_csv.write(writer)?;
490 &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc} => {
491 writer.write_all(&[1; 1])?;
492 per_commitment_point.write(writer)?;
493 remote_delayed_payment_base_key.write(writer)?;
494 remote_htlc_base_key.write(writer)?;
495 preimage.write(writer)?;
498 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
499 writer.write_all(&[2; 1])?;
500 preimage.write(writer)?;
501 writer.write_all(&byte_utils::be64_to_array(*amount))?;
503 &InputMaterial::Funding { ref funding_redeemscript } => {
504 writer.write_all(&[3; 1])?;
505 funding_redeemscript.write(writer)?;
512 impl Readable for InputMaterial {
513 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
514 let input_material = match <u8 as Readable>::read(reader)? {
516 let per_commitment_point = Readable::read(reader)?;
517 let remote_delayed_payment_base_key = Readable::read(reader)?;
518 let remote_htlc_base_key = Readable::read(reader)?;
519 let per_commitment_key = Readable::read(reader)?;
520 let input_descriptor = Readable::read(reader)?;
521 let amount = Readable::read(reader)?;
522 let htlc = Readable::read(reader)?;
523 let on_remote_tx_csv = Readable::read(reader)?;
524 InputMaterial::Revoked {
525 per_commitment_point,
526 remote_delayed_payment_base_key,
527 remote_htlc_base_key,
536 let per_commitment_point = Readable::read(reader)?;
537 let remote_delayed_payment_base_key = Readable::read(reader)?;
538 let remote_htlc_base_key = Readable::read(reader)?;
539 let preimage = Readable::read(reader)?;
540 let htlc = Readable::read(reader)?;
541 InputMaterial::RemoteHTLC {
542 per_commitment_point,
543 remote_delayed_payment_base_key,
544 remote_htlc_base_key,
550 let preimage = Readable::read(reader)?;
551 let amount = Readable::read(reader)?;
552 InputMaterial::LocalHTLC {
558 InputMaterial::Funding {
559 funding_redeemscript: Readable::read(reader)?,
562 _ => return Err(DecodeError::InvalidValue),
568 /// ClaimRequest is a descriptor structure to communicate between detection
569 /// and reaction module. They are generated by ChannelMonitor while parsing
570 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
571 /// is responsible for opportunistic aggregation, selecting and enforcing
572 /// bumping logic, building and signing transactions.
573 pub(crate) struct ClaimRequest {
574 // Block height before which claiming is exclusive to one party,
575 // after reaching it, claiming may be contentious.
576 pub(crate) absolute_timelock: u32,
577 // Timeout tx must have nLocktime set which means aggregating multiple
578 // ones must take the higher nLocktime among them to satisfy all of them.
579 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
580 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
581 // Do simplify we mark them as non-aggregable.
582 pub(crate) aggregable: bool,
583 // Basic bitcoin outpoint (txid, vout)
584 pub(crate) outpoint: BitcoinOutPoint,
585 // Following outpoint type, set of data needed to generate transaction digest
586 // and satisfy witness program.
587 pub(crate) witness_data: InputMaterial
590 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
591 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
592 #[derive(Clone, PartialEq)]
594 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
595 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
596 /// only win from it, so it's never an OnchainEvent
598 htlc_update: (HTLCSource, PaymentHash),
601 descriptor: SpendableOutputDescriptor,
605 const SERIALIZATION_VERSION: u8 = 1;
606 const MIN_SERIALIZATION_VERSION: u8 = 1;
608 #[cfg_attr(test, derive(PartialEq))]
610 pub(super) enum ChannelMonitorUpdateStep {
611 LatestLocalCommitmentTXInfo {
612 commitment_tx: LocalCommitmentTransaction,
613 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
615 LatestRemoteCommitmentTXInfo {
616 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
617 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
618 commitment_number: u64,
619 their_revocation_point: PublicKey,
622 payment_preimage: PaymentPreimage,
628 /// Used to indicate that the no future updates will occur, and likely that the latest local
629 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
631 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
632 /// think we've fallen behind!
633 should_broadcast: bool,
637 impl Writeable for ChannelMonitorUpdateStep {
638 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
640 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
642 commitment_tx.write(w)?;
643 (htlc_outputs.len() as u64).write(w)?;
644 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
650 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
652 unsigned_commitment_tx.write(w)?;
653 commitment_number.write(w)?;
654 their_revocation_point.write(w)?;
655 (htlc_outputs.len() as u64).write(w)?;
656 for &(ref output, ref source) in htlc_outputs.iter() {
658 source.as_ref().map(|b| b.as_ref()).write(w)?;
661 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
663 payment_preimage.write(w)?;
665 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
670 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
672 should_broadcast.write(w)?;
678 impl Readable for ChannelMonitorUpdateStep {
679 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
680 match Readable::read(r)? {
682 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
683 commitment_tx: Readable::read(r)?,
685 let len: u64 = Readable::read(r)?;
686 let mut res = Vec::new();
688 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
695 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
696 unsigned_commitment_tx: Readable::read(r)?,
697 commitment_number: Readable::read(r)?,
698 their_revocation_point: Readable::read(r)?,
700 let len: u64 = Readable::read(r)?;
701 let mut res = Vec::new();
703 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
710 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
711 payment_preimage: Readable::read(r)?,
715 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
716 idx: Readable::read(r)?,
717 secret: Readable::read(r)?,
721 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
722 should_broadcast: Readable::read(r)?
725 _ => Err(DecodeError::InvalidValue),
730 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
731 /// on-chain transactions to ensure no loss of funds occurs.
733 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
734 /// information and are actively monitoring the chain.
736 /// Pending Events or updated HTLCs which have not yet been read out by
737 /// get_and_clear_pending_htlcs_updated or get_and_clear_pending_events are serialized to disk and
738 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
739 /// gotten are fully handled before re-serializing the new state.
740 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
741 latest_update_id: u64,
742 commitment_transaction_number_obscure_factor: u64,
744 destination_script: Script,
745 broadcasted_local_revokable_script: Option<(Script, PublicKey, PublicKey)>,
746 remote_payment_script: Script,
747 shutdown_script: Script,
750 funding_info: (OutPoint, Script),
751 current_remote_commitment_txid: Option<Txid>,
752 prev_remote_commitment_txid: Option<Txid>,
754 remote_tx_cache: RemoteCommitmentTransaction,
755 funding_redeemscript: Script,
756 channel_value_satoshis: u64,
757 // first is the idx of the first of the two revocation points
758 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
760 on_local_tx_csv: u16,
762 commitment_secrets: CounterpartyCommitmentSecrets,
763 remote_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
764 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
765 /// Nor can we figure out their commitment numbers without the commitment transaction they are
766 /// spending. Thus, in order to claim them via revocation key, we track all the remote
767 /// commitment transactions which we find on-chain, mapping them to the commitment number which
768 /// can be used to derive the revocation key and claim the transactions.
769 remote_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
770 /// Cache used to make pruning of payment_preimages faster.
771 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
772 /// remote transactions (ie should remain pretty small).
773 /// Serialized to disk but should generally not be sent to Watchtowers.
774 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
776 // We store two local commitment transactions to avoid any race conditions where we may update
777 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
778 // various monitors for one channel being out of sync, and us broadcasting a local
779 // transaction for which we have deleted claim information on some watchtowers.
780 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
781 current_local_commitment_tx: LocalSignedTx,
783 // Used just for ChannelManager to make sure it has the latest channel data during
785 current_remote_commitment_number: u64,
786 // Used just for ChannelManager to make sure it has the latest channel data during
788 current_local_commitment_number: u64,
790 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
792 pending_htlcs_updated: Vec<HTLCUpdate>,
793 pending_events: Vec<events::Event>,
795 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
796 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
797 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
798 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
800 // If we get serialized out and re-read, we need to make sure that the chain monitoring
801 // interface knows about the TXOs that we want to be notified of spends of. We could probably
802 // be smart and derive them from the above storage fields, but its much simpler and more
803 // Obviously Correct (tm) if we just keep track of them explicitly.
804 outputs_to_watch: HashMap<Txid, Vec<Script>>,
807 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
809 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
811 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
812 // channel has been force-closed. After this is set, no further local commitment transaction
813 // updates may occur, and we panic!() if one is provided.
814 lockdown_from_offchain: bool,
816 // Set once we've signed a local commitment transaction and handed it over to our
817 // OnchainTxHandler. After this is set, no future updates to our local commitment transactions
818 // may occur, and we fail any such monitor updates.
819 local_tx_signed: bool,
821 // We simply modify last_block_hash in Channel's block_connected so that serialization is
822 // consistent but hopefully the users' copy handles block_connected in a consistent way.
823 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
824 // their last_block_hash from its state and not based on updated copies that didn't run through
825 // the full block_connected).
826 pub(crate) last_block_hash: BlockHash,
827 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
830 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
831 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
832 /// events to it, while also taking any add/update_monitor events and passing them to some remote
835 /// In general, you must always have at least one local copy in memory, which must never fail to
836 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
837 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
838 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
839 /// taking any further action such as writing the current state to disk. This should likely be
840 /// accomplished via panic!() or abort().
842 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
843 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
844 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
845 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
847 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
848 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
849 /// than calling these methods directly, the user should register implementors as listeners to the
850 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
851 /// all registered listeners in one go.
852 pub trait ManyChannelMonitor: Send + Sync {
853 /// The concrete type which signs for transactions and provides access to our channel public
855 type Keys: ChannelKeys;
857 /// Adds a monitor for the given `funding_txo`.
859 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
860 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
861 /// callbacks with the funding transaction, or any spends of it.
863 /// Further, the implementer must also ensure that each output returned in
864 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
865 /// any spends of any of the outputs.
867 /// Any spends of outputs which should have been registered which aren't passed to
868 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
869 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
871 /// Updates a monitor for the given `funding_txo`.
873 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
874 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
875 /// callbacks with the funding transaction, or any spends of it.
877 /// Further, the implementer must also ensure that each output returned in
878 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
879 /// any spends of any of the outputs.
881 /// Any spends of outputs which should have been registered which aren't passed to
882 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
883 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
885 #[cfg(any(test, feature = "fuzztarget"))]
886 /// Calls would_broadcast_at_height() on the given monitor. Used in testing to check that the
887 /// ChannelMonitor copy can never get out of sync with the Channel copy.
888 fn get_monitor_would_broadcast(&self, funding_txo: &OutPoint, height: u32) -> bool;
890 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
891 /// with success or failure.
893 /// You should probably just call through to
894 /// ChannelMonitor::get_and_clear_pending_htlcs_updated() for each ChannelMonitor and return
896 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate>;
899 #[cfg(any(test, feature = "fuzztarget"))]
900 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
901 /// underlying object
902 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
903 fn eq(&self, other: &Self) -> bool {
904 if self.latest_update_id != other.latest_update_id ||
905 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
906 self.destination_script != other.destination_script ||
907 self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
908 self.remote_payment_script != other.remote_payment_script ||
909 self.keys.pubkeys() != other.keys.pubkeys() ||
910 self.funding_info != other.funding_info ||
911 self.current_remote_commitment_txid != other.current_remote_commitment_txid ||
912 self.prev_remote_commitment_txid != other.prev_remote_commitment_txid ||
913 self.remote_tx_cache != other.remote_tx_cache ||
914 self.funding_redeemscript != other.funding_redeemscript ||
915 self.channel_value_satoshis != other.channel_value_satoshis ||
916 self.their_cur_revocation_points != other.their_cur_revocation_points ||
917 self.on_local_tx_csv != other.on_local_tx_csv ||
918 self.commitment_secrets != other.commitment_secrets ||
919 self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
920 self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
921 self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
922 self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
923 self.current_remote_commitment_number != other.current_remote_commitment_number ||
924 self.current_local_commitment_number != other.current_local_commitment_number ||
925 self.current_local_commitment_tx != other.current_local_commitment_tx ||
926 self.payment_preimages != other.payment_preimages ||
927 self.pending_htlcs_updated != other.pending_htlcs_updated ||
928 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
929 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
930 self.outputs_to_watch != other.outputs_to_watch ||
931 self.lockdown_from_offchain != other.lockdown_from_offchain ||
932 self.local_tx_signed != other.local_tx_signed
941 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
942 /// Writes this monitor into the given writer, suitable for writing to disk.
944 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
945 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
946 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
947 /// returned block hash and the the current chain and then reconnecting blocks to get to the
948 /// best chain) upon deserializing the object!
949 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
950 //TODO: We still write out all the serialization here manually instead of using the fancy
951 //serialization framework we have, we should migrate things over to it.
952 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
953 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
955 self.latest_update_id.write(writer)?;
957 // Set in initial Channel-object creation, so should always be set by now:
958 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
960 self.destination_script.write(writer)?;
961 if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
962 writer.write_all(&[0; 1])?;
963 broadcasted_local_revokable_script.0.write(writer)?;
964 broadcasted_local_revokable_script.1.write(writer)?;
965 broadcasted_local_revokable_script.2.write(writer)?;
967 writer.write_all(&[1; 1])?;
970 self.remote_payment_script.write(writer)?;
971 self.shutdown_script.write(writer)?;
973 self.keys.write(writer)?;
974 writer.write_all(&self.funding_info.0.txid[..])?;
975 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
976 self.funding_info.1.write(writer)?;
977 self.current_remote_commitment_txid.write(writer)?;
978 self.prev_remote_commitment_txid.write(writer)?;
980 self.remote_tx_cache.write(writer)?;
981 self.funding_redeemscript.write(writer)?;
982 self.channel_value_satoshis.write(writer)?;
984 match self.their_cur_revocation_points {
985 Some((idx, pubkey, second_option)) => {
986 writer.write_all(&byte_utils::be48_to_array(idx))?;
987 writer.write_all(&pubkey.serialize())?;
988 match second_option {
989 Some(second_pubkey) => {
990 writer.write_all(&second_pubkey.serialize())?;
993 writer.write_all(&[0; 33])?;
998 writer.write_all(&byte_utils::be48_to_array(0))?;
1002 writer.write_all(&byte_utils::be16_to_array(self.on_local_tx_csv))?;
1004 self.commitment_secrets.write(writer)?;
1006 macro_rules! serialize_htlc_in_commitment {
1007 ($htlc_output: expr) => {
1008 writer.write_all(&[$htlc_output.offered as u8; 1])?;
1009 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
1010 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
1011 writer.write_all(&$htlc_output.payment_hash.0[..])?;
1012 $htlc_output.transaction_output_index.write(writer)?;
1016 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
1017 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
1018 writer.write_all(&txid[..])?;
1019 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
1020 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
1021 serialize_htlc_in_commitment!(htlc_output);
1022 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1026 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
1027 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
1028 writer.write_all(&txid[..])?;
1029 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
1030 (txouts.len() as u64).write(writer)?;
1031 for script in txouts.iter() {
1032 script.write(writer)?;
1036 writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
1037 for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
1038 writer.write_all(&payment_hash.0[..])?;
1039 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1042 macro_rules! serialize_local_tx {
1043 ($local_tx: expr) => {
1044 $local_tx.txid.write(writer)?;
1045 writer.write_all(&$local_tx.revocation_key.serialize())?;
1046 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
1047 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
1048 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
1049 writer.write_all(&$local_tx.per_commitment_point.serialize())?;
1051 writer.write_all(&byte_utils::be32_to_array($local_tx.feerate_per_kw))?;
1052 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
1053 for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
1054 serialize_htlc_in_commitment!(htlc_output);
1055 if let &Some(ref their_sig) = sig {
1057 writer.write_all(&their_sig.serialize_compact())?;
1061 htlc_source.write(writer)?;
1066 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
1067 writer.write_all(&[1; 1])?;
1068 serialize_local_tx!(prev_local_tx);
1070 writer.write_all(&[0; 1])?;
1073 serialize_local_tx!(self.current_local_commitment_tx);
1075 writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
1076 writer.write_all(&byte_utils::be48_to_array(self.current_local_commitment_number))?;
1078 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1079 for payment_preimage in self.payment_preimages.values() {
1080 writer.write_all(&payment_preimage.0[..])?;
1083 writer.write_all(&byte_utils::be64_to_array(self.pending_htlcs_updated.len() as u64))?;
1084 for data in self.pending_htlcs_updated.iter() {
1085 data.write(writer)?;
1088 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1089 for event in self.pending_events.iter() {
1090 event.write(writer)?;
1093 self.last_block_hash.write(writer)?;
1095 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1096 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1097 writer.write_all(&byte_utils::be32_to_array(**target))?;
1098 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1099 for ev in events.iter() {
1101 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1103 htlc_update.0.write(writer)?;
1104 htlc_update.1.write(writer)?;
1106 OnchainEvent::MaturingOutput { ref descriptor } => {
1108 descriptor.write(writer)?;
1114 (self.outputs_to_watch.len() as u64).write(writer)?;
1115 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1116 txid.write(writer)?;
1117 (output_scripts.len() as u64).write(writer)?;
1118 for script in output_scripts.iter() {
1119 script.write(writer)?;
1122 self.onchain_tx_handler.write(writer)?;
1124 self.lockdown_from_offchain.write(writer)?;
1125 self.local_tx_signed.write(writer)?;
1131 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1132 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1133 on_remote_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1134 remote_htlc_base_key: &PublicKey, remote_delayed_payment_base_key: &PublicKey,
1135 on_local_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1136 commitment_transaction_number_obscure_factor: u64,
1137 initial_local_commitment_tx: LocalCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1139 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1140 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1141 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1142 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1143 let remote_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1145 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() };
1147 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_local_tx_csv);
1149 let local_tx_sequence = initial_local_commitment_tx.unsigned_tx.input[0].sequence as u64;
1150 let local_tx_locktime = initial_local_commitment_tx.unsigned_tx.lock_time as u64;
1151 let local_commitment_tx = LocalSignedTx {
1152 txid: initial_local_commitment_tx.txid(),
1153 revocation_key: initial_local_commitment_tx.local_keys.revocation_key,
1154 a_htlc_key: initial_local_commitment_tx.local_keys.a_htlc_key,
1155 b_htlc_key: initial_local_commitment_tx.local_keys.b_htlc_key,
1156 delayed_payment_key: initial_local_commitment_tx.local_keys.a_delayed_payment_key,
1157 per_commitment_point: initial_local_commitment_tx.local_keys.per_commitment_point,
1158 feerate_per_kw: initial_local_commitment_tx.feerate_per_kw,
1159 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1161 // Returning a monitor error before updating tracking points means in case of using
1162 // a concurrent watchtower implementation for same channel, if this one doesn't
1163 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1164 // for which you want to spend outputs. We're NOT robust again this scenario right
1165 // now but we should consider it later.
1166 onchain_tx_handler.provide_latest_local_tx(initial_local_commitment_tx).unwrap();
1169 latest_update_id: 0,
1170 commitment_transaction_number_obscure_factor,
1172 destination_script: destination_script.clone(),
1173 broadcasted_local_revokable_script: None,
1174 remote_payment_script,
1179 current_remote_commitment_txid: None,
1180 prev_remote_commitment_txid: None,
1183 funding_redeemscript,
1184 channel_value_satoshis: channel_value_satoshis,
1185 their_cur_revocation_points: None,
1189 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1190 remote_claimable_outpoints: HashMap::new(),
1191 remote_commitment_txn_on_chain: HashMap::new(),
1192 remote_hash_commitment_number: HashMap::new(),
1194 prev_local_signed_commitment_tx: None,
1195 current_local_commitment_tx: local_commitment_tx,
1196 current_remote_commitment_number: 1 << 48,
1197 current_local_commitment_number: 0xffff_ffff_ffff - ((((local_tx_sequence & 0xffffff) << 3*8) | (local_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1199 payment_preimages: HashMap::new(),
1200 pending_htlcs_updated: Vec::new(),
1201 pending_events: Vec::new(),
1203 onchain_events_waiting_threshold_conf: HashMap::new(),
1204 outputs_to_watch: HashMap::new(),
1208 lockdown_from_offchain: false,
1209 local_tx_signed: false,
1211 last_block_hash: Default::default(),
1212 secp_ctx: Secp256k1::new(),
1216 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1217 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1218 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1219 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1220 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1221 return Err(MonitorUpdateError("Previous secret did not match new one"));
1224 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1225 // events for now-revoked/fulfilled HTLCs.
1226 if let Some(txid) = self.prev_remote_commitment_txid.take() {
1227 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1232 if !self.payment_preimages.is_empty() {
1233 let cur_local_signed_commitment_tx = &self.current_local_commitment_tx;
1234 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1235 let min_idx = self.get_min_seen_secret();
1236 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1238 self.payment_preimages.retain(|&k, _| {
1239 for &(ref htlc, _, _) in cur_local_signed_commitment_tx.htlc_outputs.iter() {
1240 if k == htlc.payment_hash {
1244 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1245 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1246 if k == htlc.payment_hash {
1251 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1258 remote_hash_commitment_number.remove(&k);
1267 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1268 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1269 /// possibly future revocation/preimage information) to claim outputs where possible.
1270 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1271 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 {
1272 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1273 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1274 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1276 for &(ref htlc, _) in &htlc_outputs {
1277 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1280 let new_txid = unsigned_commitment_tx.txid();
1281 log_trace!(logger, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1282 log_trace!(logger, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1283 self.prev_remote_commitment_txid = self.current_remote_commitment_txid.take();
1284 self.current_remote_commitment_txid = Some(new_txid);
1285 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1286 self.current_remote_commitment_number = commitment_number;
1287 //TODO: Merge this into the other per-remote-transaction output storage stuff
1288 match self.their_cur_revocation_points {
1289 Some(old_points) => {
1290 if old_points.0 == commitment_number + 1 {
1291 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1292 } else if old_points.0 == commitment_number + 2 {
1293 if let Some(old_second_point) = old_points.2 {
1294 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1296 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1299 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1303 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1306 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1307 for htlc in htlc_outputs {
1308 if htlc.0.transaction_output_index.is_some() {
1312 self.remote_tx_cache.per_htlc.insert(new_txid, htlcs);
1315 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1316 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1317 /// is important that any clones of this channel monitor (including remote clones) by kept
1318 /// up-to-date as our local commitment transaction is updated.
1319 /// Panics if set_on_local_tx_csv has never been called.
1320 pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1321 if self.local_tx_signed {
1322 return Err(MonitorUpdateError("A local commitment tx has already been signed, no new local commitment txn can be sent to our counterparty"));
1324 let txid = commitment_tx.txid();
1325 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1326 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1327 let mut new_local_commitment_tx = LocalSignedTx {
1329 revocation_key: commitment_tx.local_keys.revocation_key,
1330 a_htlc_key: commitment_tx.local_keys.a_htlc_key,
1331 b_htlc_key: commitment_tx.local_keys.b_htlc_key,
1332 delayed_payment_key: commitment_tx.local_keys.a_delayed_payment_key,
1333 per_commitment_point: commitment_tx.local_keys.per_commitment_point,
1334 feerate_per_kw: commitment_tx.feerate_per_kw,
1335 htlc_outputs: htlc_outputs,
1337 // Returning a monitor error before updating tracking points means in case of using
1338 // a concurrent watchtower implementation for same channel, if this one doesn't
1339 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1340 // for which you want to spend outputs. We're NOT robust again this scenario right
1341 // now but we should consider it later.
1342 if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx) {
1343 return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1345 self.current_local_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1346 mem::swap(&mut new_local_commitment_tx, &mut self.current_local_commitment_tx);
1347 self.prev_local_signed_commitment_tx = Some(new_local_commitment_tx);
1351 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1352 /// commitment_tx_infos which contain the payment hash have been revoked.
1353 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1354 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1357 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1358 where B::Target: BroadcasterInterface,
1361 for tx in self.get_latest_local_commitment_txn(logger).iter() {
1362 broadcaster.broadcast_transaction(tx);
1366 /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
1367 pub(super) fn update_monitor_ooo<L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, logger: &L) -> Result<(), MonitorUpdateError> where L::Target: Logger {
1368 for update in updates.updates.drain(..) {
1370 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1371 if self.lockdown_from_offchain { panic!(); }
1372 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1374 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1375 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1376 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1377 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1378 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1379 self.provide_secret(idx, secret)?,
1380 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
1383 self.latest_update_id = updates.update_id;
1387 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1390 /// panics if the given update is not the next update by update_id.
1391 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1392 where B::Target: BroadcasterInterface,
1395 if self.latest_update_id + 1 != updates.update_id {
1396 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1398 for update in updates.updates.drain(..) {
1400 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1401 if self.lockdown_from_offchain { panic!(); }
1402 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1404 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1405 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1406 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1407 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1408 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1409 self.provide_secret(idx, secret)?,
1410 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1411 self.lockdown_from_offchain = true;
1412 if should_broadcast {
1413 self.broadcast_latest_local_commitment_txn(broadcaster, logger);
1415 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");
1420 self.latest_update_id = updates.update_id;
1424 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1426 pub fn get_latest_update_id(&self) -> u64 {
1427 self.latest_update_id
1430 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1431 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1435 /// Gets a list of txids, with their output scripts (in the order they appear in the
1436 /// transaction), which we must learn about spends of via block_connected().
1437 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1438 &self.outputs_to_watch
1441 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1442 /// Generally useful when deserializing as during normal operation the return values of
1443 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1444 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1445 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1446 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1447 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1448 for (idx, output) in outputs.iter().enumerate() {
1449 res.push(((*txid).clone(), idx as u32, output));
1455 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1456 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_htlcs_updated().
1457 pub fn get_and_clear_pending_htlcs_updated(&mut self) -> Vec<HTLCUpdate> {
1458 let mut ret = Vec::new();
1459 mem::swap(&mut ret, &mut self.pending_htlcs_updated);
1463 /// Gets the list of pending events which were generated by previous actions, clearing the list
1466 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1467 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1468 /// no internal locking in ChannelMonitors.
1469 pub fn get_and_clear_pending_events(&mut self) -> Vec<events::Event> {
1470 let mut ret = Vec::new();
1471 mem::swap(&mut ret, &mut self.pending_events);
1475 /// Can only fail if idx is < get_min_seen_secret
1476 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1477 self.commitment_secrets.get_secret(idx)
1480 pub(super) fn get_min_seen_secret(&self) -> u64 {
1481 self.commitment_secrets.get_min_seen_secret()
1484 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1485 self.current_remote_commitment_number
1488 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1489 self.current_local_commitment_number
1492 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1493 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1494 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1495 /// HTLC-Success/HTLC-Timeout transactions.
1496 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1497 /// revoked remote commitment tx
1498 fn check_spend_remote_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1499 // Most secp and related errors trying to create keys means we have no hope of constructing
1500 // a spend transaction...so we return no transactions to broadcast
1501 let mut claimable_outpoints = Vec::new();
1502 let mut watch_outputs = Vec::new();
1504 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1505 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1507 macro_rules! ignore_error {
1508 ( $thing : expr ) => {
1511 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1516 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);
1517 if commitment_number >= self.get_min_seen_secret() {
1518 let secret = self.get_secret(commitment_number).unwrap();
1519 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1520 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1521 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1522 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));
1524 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.remote_tx_cache.on_remote_tx_csv, &delayed_key);
1525 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1527 // First, process non-htlc outputs (to_local & to_remote)
1528 for (idx, outp) in tx.output.iter().enumerate() {
1529 if outp.script_pubkey == revokeable_p2wsh {
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: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_remote_tx_csv: self.remote_tx_cache.on_remote_tx_csv};
1531 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});
1535 // Then, try to find revoked htlc outputs
1536 if let Some(ref per_commitment_data) = per_commitment_option {
1537 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1538 if let Some(transaction_output_index) = htlc.transaction_output_index {
1539 if transaction_output_index as usize >= tx.output.len() ||
1540 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1541 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1543 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};
1544 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1549 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1550 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1551 // We're definitely a remote commitment transaction!
1552 log_trace!(logger, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1553 watch_outputs.append(&mut tx.output.clone());
1554 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1556 macro_rules! check_htlc_fails {
1557 ($txid: expr, $commitment_tx: expr) => {
1558 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1559 for &(ref htlc, ref source_option) in outpoints.iter() {
1560 if let &Some(ref source) = source_option {
1561 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1562 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1563 hash_map::Entry::Occupied(mut entry) => {
1564 let e = entry.get_mut();
1565 e.retain(|ref event| {
1567 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1568 return htlc_update.0 != **source
1573 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1575 hash_map::Entry::Vacant(entry) => {
1576 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1584 if let Some(ref txid) = self.current_remote_commitment_txid {
1585 check_htlc_fails!(txid, "current");
1587 if let Some(ref txid) = self.prev_remote_commitment_txid {
1588 check_htlc_fails!(txid, "remote");
1590 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1592 } else if let Some(per_commitment_data) = per_commitment_option {
1593 // While this isn't useful yet, there is a potential race where if a counterparty
1594 // revokes a state at the same time as the commitment transaction for that state is
1595 // confirmed, and the watchtower receives the block before the user, the user could
1596 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1597 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1598 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1600 watch_outputs.append(&mut tx.output.clone());
1601 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1603 log_trace!(logger, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1605 macro_rules! check_htlc_fails {
1606 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1607 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1608 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1609 if let &Some(ref source) = source_option {
1610 // Check if the HTLC is present in the commitment transaction that was
1611 // broadcast, but not if it was below the dust limit, which we should
1612 // fail backwards immediately as there is no way for us to learn the
1613 // payment_preimage.
1614 // Note that if the dust limit were allowed to change between
1615 // commitment transactions we'd want to be check whether *any*
1616 // broadcastable commitment transaction has the HTLC in it, but it
1617 // cannot currently change after channel initialization, so we don't
1619 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1620 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1624 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);
1625 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1626 hash_map::Entry::Occupied(mut entry) => {
1627 let e = entry.get_mut();
1628 e.retain(|ref event| {
1630 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1631 return htlc_update.0 != **source
1636 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1638 hash_map::Entry::Vacant(entry) => {
1639 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1647 if let Some(ref txid) = self.current_remote_commitment_txid {
1648 check_htlc_fails!(txid, "current", 'current_loop);
1650 if let Some(ref txid) = self.prev_remote_commitment_txid {
1651 check_htlc_fails!(txid, "previous", 'prev_loop);
1654 if let Some(revocation_points) = self.their_cur_revocation_points {
1655 let revocation_point_option =
1656 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1657 else if let Some(point) = revocation_points.2.as_ref() {
1658 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1660 if let Some(revocation_point) = revocation_point_option {
1661 self.remote_payment_script = {
1662 // Note that the Network here is ignored as we immediately drop the address for the
1663 // script_pubkey version
1664 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1665 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1668 // Then, try to find htlc outputs
1669 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1670 if let Some(transaction_output_index) = htlc.transaction_output_index {
1671 if transaction_output_index as usize >= tx.output.len() ||
1672 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1673 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1675 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1676 let aggregable = if !htlc.offered { false } else { true };
1677 if preimage.is_some() || !htlc.offered {
1678 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() };
1679 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1686 (claimable_outpoints, (commitment_txid, watch_outputs))
1689 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1690 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 {
1691 let htlc_txid = tx.txid();
1692 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1693 return (Vec::new(), None)
1696 macro_rules! ignore_error {
1697 ( $thing : expr ) => {
1700 Err(_) => return (Vec::new(), None)
1705 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1706 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1707 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1709 log_trace!(logger, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1710 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 };
1711 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 });
1712 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1715 fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1716 let mut claim_requests = Vec::with_capacity(local_tx.htlc_outputs.len());
1717 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1719 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.on_local_tx_csv, &local_tx.delayed_payment_key);
1720 let broadcasted_local_revokable_script = Some((redeemscript.to_v0_p2wsh(), local_tx.per_commitment_point.clone(), local_tx.revocation_key.clone()));
1722 for &(ref htlc, _, _) in local_tx.htlc_outputs.iter() {
1723 if let Some(transaction_output_index) = htlc.transaction_output_index {
1724 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: local_tx.txid, vout: transaction_output_index as u32 },
1725 witness_data: InputMaterial::LocalHTLC {
1726 preimage: if !htlc.offered {
1727 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1728 Some(preimage.clone())
1730 // We can't build an HTLC-Success transaction without the preimage
1734 amount: htlc.amount_msat,
1736 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1740 (claim_requests, watch_outputs, broadcasted_local_revokable_script)
1743 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1744 /// revoked using data in local_claimable_outpoints.
1745 /// Should not be used if check_spend_revoked_transaction succeeds.
1746 fn check_spend_local_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1747 let commitment_txid = tx.txid();
1748 let mut claim_requests = Vec::new();
1749 let mut watch_outputs = Vec::new();
1751 macro_rules! wait_threshold_conf {
1752 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1753 log_trace!(logger, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1754 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1755 hash_map::Entry::Occupied(mut entry) => {
1756 let e = entry.get_mut();
1757 e.retain(|ref event| {
1759 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1760 return htlc_update.0 != $source
1765 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1767 hash_map::Entry::Vacant(entry) => {
1768 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1774 macro_rules! append_onchain_update {
1775 ($updates: expr) => {
1776 claim_requests = $updates.0;
1777 watch_outputs.append(&mut $updates.1);
1778 self.broadcasted_local_revokable_script = $updates.2;
1782 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1783 let mut is_local_tx = false;
1785 if self.current_local_commitment_tx.txid == commitment_txid {
1787 log_trace!(logger, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1788 let mut res = self.broadcast_by_local_state(tx, &self.current_local_commitment_tx);
1789 append_onchain_update!(res);
1790 } else if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1791 if local_tx.txid == commitment_txid {
1793 log_trace!(logger, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1794 let mut res = self.broadcast_by_local_state(tx, local_tx);
1795 append_onchain_update!(res);
1799 macro_rules! fail_dust_htlcs_after_threshold_conf {
1800 ($local_tx: expr) => {
1801 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1802 if htlc.transaction_output_index.is_none() {
1803 if let &Some(ref source) = source {
1804 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1812 fail_dust_htlcs_after_threshold_conf!(self.current_local_commitment_tx);
1813 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1814 fail_dust_htlcs_after_threshold_conf!(local_tx);
1818 (claim_requests, (commitment_txid, watch_outputs))
1821 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1822 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1823 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1824 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1825 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1826 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1827 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1828 /// out-of-band the other node operator to coordinate with him if option is available to you.
1829 /// In any-case, choice is up to the user.
1830 pub fn get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1831 log_trace!(logger, "Getting signed latest local commitment transaction!");
1832 self.local_tx_signed = true;
1833 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1834 let txid = commitment_tx.txid();
1835 let mut res = vec![commitment_tx];
1836 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1837 if let Some(vout) = htlc.0.transaction_output_index {
1838 let preimage = if !htlc.0.offered {
1839 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1840 // We can't build an HTLC-Success transaction without the preimage
1844 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1845 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1850 // 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.
1851 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1857 /// Unsafe test-only version of get_latest_local_commitment_txn used by our test framework
1858 /// to bypass LocalCommitmentTransaction state update lockdown after signature and generate
1859 /// revoked commitment transaction.
1860 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1861 pub fn unsafe_get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1862 log_trace!(logger, "Getting signed copy of latest local commitment transaction!");
1863 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_local_tx(&self.funding_redeemscript) {
1864 let txid = commitment_tx.txid();
1865 let mut res = vec![commitment_tx];
1866 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1867 if let Some(vout) = htlc.0.transaction_output_index {
1868 let preimage = if !htlc.0.offered {
1869 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1870 // We can't build an HTLC-Success transaction without the preimage
1874 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1875 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1885 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1886 /// ChainListener::block_connected.
1887 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1888 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1890 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>)>
1891 where B::Target: BroadcasterInterface,
1892 F::Target: FeeEstimator,
1895 for tx in txn_matched {
1896 let mut output_val = 0;
1897 for out in tx.output.iter() {
1898 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1899 output_val += out.value;
1900 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1904 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1905 let mut watch_outputs = Vec::new();
1906 let mut claimable_outpoints = Vec::new();
1907 for tx in txn_matched {
1908 if tx.input.len() == 1 {
1909 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1910 // commitment transactions and HTLC transactions will all only ever have one input,
1911 // which is an easy way to filter out any potential non-matching txn for lazy
1913 let prevout = &tx.input[0].previous_output;
1914 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1915 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1916 let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height, &logger);
1917 if !new_outputs.1.is_empty() {
1918 watch_outputs.push(new_outputs);
1920 if new_outpoints.is_empty() {
1921 let (mut new_outpoints, new_outputs) = self.check_spend_local_transaction(&tx, height, &logger);
1922 if !new_outputs.1.is_empty() {
1923 watch_outputs.push(new_outputs);
1925 claimable_outpoints.append(&mut new_outpoints);
1927 claimable_outpoints.append(&mut new_outpoints);
1930 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1931 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height, &logger);
1932 claimable_outpoints.append(&mut new_outpoints);
1933 if let Some(new_outputs) = new_outputs_option {
1934 watch_outputs.push(new_outputs);
1939 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1940 // can also be resolved in a few other ways which can have more than one output. Thus,
1941 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1942 self.is_resolving_htlc_output(&tx, height, &logger);
1944 self.is_paying_spendable_output(&tx, height, &logger);
1946 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1947 if should_broadcast {
1948 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() }});
1950 if should_broadcast {
1951 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1952 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_local_state(&commitment_tx, &self.current_local_commitment_tx);
1953 if !new_outputs.is_empty() {
1954 watch_outputs.push((self.current_local_commitment_tx.txid.clone(), new_outputs));
1956 claimable_outpoints.append(&mut new_outpoints);
1959 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1962 OnchainEvent::HTLCUpdate { htlc_update } => {
1963 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1964 self.pending_htlcs_updated.push(HTLCUpdate {
1965 payment_hash: htlc_update.1,
1966 payment_preimage: None,
1967 source: htlc_update.0,
1970 OnchainEvent::MaturingOutput { descriptor } => {
1971 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1972 self.pending_events.push(events::Event::SpendableOutputs {
1973 outputs: vec![descriptor]
1979 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1981 self.last_block_hash = block_hash.clone();
1982 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1983 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1989 fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)
1990 where B::Target: BroadcasterInterface,
1991 F::Target: FeeEstimator,
1994 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1995 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1997 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1998 //- maturing spendable output has transaction paying us has been disconnected
2001 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2003 self.last_block_hash = block_hash.clone();
2006 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2007 let local_outputs: Vec<&HTLCOutputInCommitment> = self.current_local_commitment_tx.htlc_outputs
2008 .iter().map(|&(ref a, _, _)| a).collect();
2009 let mut prev_remote_outputs = Vec::new();
2010 if let Some(ref txid) = self.prev_remote_commitment_txid {
2011 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2012 prev_remote_outputs = htlc_outputs.iter().map(|&(ref a, _)| a).collect();
2015 let mut curr_remote_outputs = Vec::new();
2016 if let Some(ref txid) = self.current_remote_commitment_txid {
2017 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2018 curr_remote_outputs = htlc_outputs.iter().map(|&(ref a, _)| a).collect()
2021 let remote_outputs = [curr_remote_outputs, prev_remote_outputs].concat();
2022 ChannelMonitor::<ChanSigner>::would_broadcast_at_height_given_htlcs(local_outputs, remote_outputs, height, &self.payment_preimages, logger)
2025 pub(super) fn would_broadcast_at_height_given_htlcs<L: Deref>(local_htlc_outputs: Vec<&HTLCOutputInCommitment>, remote_htlc_outputs: Vec<&HTLCOutputInCommitment>, height: u32, preimages: &HashMap<PaymentHash, PaymentPreimage>, logger: &L) -> bool where L::Target: Logger {
2026 // We need to consider all HTLCs which are:
2027 // * in any unrevoked remote commitment transaction, as they could broadcast said
2028 // transactions and we'd end up in a race, or
2029 // * are in our latest local commitment transaction, as this is the thing we will
2030 // broadcast if we go on-chain.
2031 // Note that we consider HTLCs which were below dust threshold here - while they don't
2032 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2033 // to the source, and if we don't fail the channel we will have to ensure that the next
2034 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2035 // easier to just fail the channel as this case should be rare enough anyway.
2036 macro_rules! scan_commitment {
2037 ($htlcs: expr, $local_tx: expr) => {
2038 for ref htlc in $htlcs {
2039 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2040 // chain with enough room to claim the HTLC without our counterparty being able to
2041 // time out the HTLC first.
2042 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2043 // concern is being able to claim the corresponding inbound HTLC (on another
2044 // channel) before it expires. In fact, we don't even really care if our
2045 // counterparty here claims such an outbound HTLC after it expired as long as we
2046 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2047 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2048 // we give ourselves a few blocks of headroom after expiration before going
2049 // on-chain for an expired HTLC.
2050 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2051 // from us until we've reached the point where we go on-chain with the
2052 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2053 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2054 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2055 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2056 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2057 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2058 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2059 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2060 // The final, above, condition is checked for statically in channelmanager
2061 // with CHECK_CLTV_EXPIRY_SANITY_2.
2062 let htlc_outbound = $local_tx == htlc.offered;
2063 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2064 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && preimages.contains_key(&htlc.payment_hash)) {
2065 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2072 scan_commitment!(local_htlc_outputs, true);
2073 scan_commitment!(remote_htlc_outputs, false);
2078 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2079 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2080 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2081 'outer_loop: for input in &tx.input {
2082 let mut payment_data = None;
2083 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2084 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2085 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2086 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2088 macro_rules! log_claim {
2089 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2090 // We found the output in question, but aren't failing it backwards
2091 // as we have no corresponding source and no valid remote commitment txid
2092 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2093 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2094 let outbound_htlc = $local_tx == $htlc.offered;
2095 if ($local_tx && revocation_sig_claim) ||
2096 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2097 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2098 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2099 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2100 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2102 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2103 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2104 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2105 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2110 macro_rules! check_htlc_valid_remote {
2111 ($remote_txid: expr, $htlc_output: expr) => {
2112 if let Some(txid) = $remote_txid {
2113 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2114 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2115 if let &Some(ref source) = pending_source {
2116 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2117 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2126 macro_rules! scan_commitment {
2127 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2128 for (ref htlc_output, source_option) in $htlcs {
2129 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2130 if let Some(ref source) = source_option {
2131 log_claim!($tx_info, $local_tx, htlc_output, true);
2132 // We have a resolution of an HTLC either from one of our latest
2133 // local commitment transactions or an unrevoked remote commitment
2134 // transaction. This implies we either learned a preimage, the HTLC
2135 // has timed out, or we screwed up. In any case, we should now
2136 // resolve the source HTLC with the original sender.
2137 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2138 } else if !$local_tx {
2139 check_htlc_valid_remote!(self.current_remote_commitment_txid, htlc_output);
2140 if payment_data.is_none() {
2141 check_htlc_valid_remote!(self.prev_remote_commitment_txid, htlc_output);
2144 if payment_data.is_none() {
2145 log_claim!($tx_info, $local_tx, htlc_output, false);
2146 continue 'outer_loop;
2153 if input.previous_output.txid == self.current_local_commitment_tx.txid {
2154 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2155 "our latest local commitment tx", true);
2157 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2158 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2159 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2160 "our previous local commitment tx", true);
2163 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2164 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2165 "remote commitment tx", false);
2168 // Check that scan_commitment, above, decided there is some source worth relaying an
2169 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2170 if let Some((source, payment_hash)) = payment_data {
2171 let mut payment_preimage = PaymentPreimage([0; 32]);
2172 if accepted_preimage_claim {
2173 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2174 payment_preimage.0.copy_from_slice(&input.witness[3]);
2175 self.pending_htlcs_updated.push(HTLCUpdate {
2177 payment_preimage: Some(payment_preimage),
2181 } else if offered_preimage_claim {
2182 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2183 payment_preimage.0.copy_from_slice(&input.witness[1]);
2184 self.pending_htlcs_updated.push(HTLCUpdate {
2186 payment_preimage: Some(payment_preimage),
2191 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);
2192 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2193 hash_map::Entry::Occupied(mut entry) => {
2194 let e = entry.get_mut();
2195 e.retain(|ref event| {
2197 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2198 return htlc_update.0 != source
2203 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2205 hash_map::Entry::Vacant(entry) => {
2206 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2214 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2215 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2216 let mut spendable_output = None;
2217 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2218 if outp.script_pubkey == self.destination_script {
2219 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2220 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2221 output: outp.clone(),
2224 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2225 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2226 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2227 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2228 per_commitment_point: broadcasted_local_revokable_script.1,
2229 to_self_delay: self.on_local_tx_csv,
2230 output: outp.clone(),
2231 key_derivation_params: self.keys.key_derivation_params(),
2232 remote_revocation_pubkey: broadcasted_local_revokable_script.2.clone(),
2236 } else if self.remote_payment_script == outp.script_pubkey {
2237 spendable_output = Some(SpendableOutputDescriptor::StaticOutputRemotePayment {
2238 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2239 output: outp.clone(),
2240 key_derivation_params: self.keys.key_derivation_params(),
2243 } else if outp.script_pubkey == self.shutdown_script {
2244 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2245 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2246 output: outp.clone(),
2250 if let Some(spendable_output) = spendable_output {
2251 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2252 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2253 hash_map::Entry::Occupied(mut entry) => {
2254 let e = entry.get_mut();
2255 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2257 hash_map::Entry::Vacant(entry) => {
2258 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2265 const MAX_ALLOC_SIZE: usize = 64*1024;
2267 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2268 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2269 macro_rules! unwrap_obj {
2273 Err(_) => return Err(DecodeError::InvalidValue),
2278 let _ver: u8 = Readable::read(reader)?;
2279 let min_ver: u8 = Readable::read(reader)?;
2280 if min_ver > SERIALIZATION_VERSION {
2281 return Err(DecodeError::UnknownVersion);
2284 let latest_update_id: u64 = Readable::read(reader)?;
2285 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2287 let destination_script = Readable::read(reader)?;
2288 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2290 let revokable_address = Readable::read(reader)?;
2291 let per_commitment_point = Readable::read(reader)?;
2292 let revokable_script = Readable::read(reader)?;
2293 Some((revokable_address, per_commitment_point, revokable_script))
2296 _ => return Err(DecodeError::InvalidValue),
2298 let remote_payment_script = Readable::read(reader)?;
2299 let shutdown_script = Readable::read(reader)?;
2301 let keys = Readable::read(reader)?;
2302 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2303 // barely-init'd ChannelMonitors that we can't do anything with.
2304 let outpoint = OutPoint {
2305 txid: Readable::read(reader)?,
2306 index: Readable::read(reader)?,
2308 let funding_info = (outpoint, Readable::read(reader)?);
2309 let current_remote_commitment_txid = Readable::read(reader)?;
2310 let prev_remote_commitment_txid = Readable::read(reader)?;
2312 let remote_tx_cache = Readable::read(reader)?;
2313 let funding_redeemscript = Readable::read(reader)?;
2314 let channel_value_satoshis = Readable::read(reader)?;
2316 let their_cur_revocation_points = {
2317 let first_idx = <U48 as Readable>::read(reader)?.0;
2321 let first_point = Readable::read(reader)?;
2322 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2323 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2324 Some((first_idx, first_point, None))
2326 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2331 let on_local_tx_csv: u16 = Readable::read(reader)?;
2333 let commitment_secrets = Readable::read(reader)?;
2335 macro_rules! read_htlc_in_commitment {
2338 let offered: bool = Readable::read(reader)?;
2339 let amount_msat: u64 = Readable::read(reader)?;
2340 let cltv_expiry: u32 = Readable::read(reader)?;
2341 let payment_hash: PaymentHash = Readable::read(reader)?;
2342 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2344 HTLCOutputInCommitment {
2345 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2351 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2352 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2353 for _ in 0..remote_claimable_outpoints_len {
2354 let txid: Txid = Readable::read(reader)?;
2355 let htlcs_count: u64 = Readable::read(reader)?;
2356 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2357 for _ in 0..htlcs_count {
2358 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2360 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2361 return Err(DecodeError::InvalidValue);
2365 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2366 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2367 for _ in 0..remote_commitment_txn_on_chain_len {
2368 let txid: Txid = Readable::read(reader)?;
2369 let commitment_number = <U48 as Readable>::read(reader)?.0;
2370 let outputs_count = <u64 as Readable>::read(reader)?;
2371 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2372 for _ in 0..outputs_count {
2373 outputs.push(Readable::read(reader)?);
2375 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2376 return Err(DecodeError::InvalidValue);
2380 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2381 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2382 for _ in 0..remote_hash_commitment_number_len {
2383 let payment_hash: PaymentHash = Readable::read(reader)?;
2384 let commitment_number = <U48 as Readable>::read(reader)?.0;
2385 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2386 return Err(DecodeError::InvalidValue);
2390 macro_rules! read_local_tx {
2393 let txid = Readable::read(reader)?;
2394 let revocation_key = Readable::read(reader)?;
2395 let a_htlc_key = Readable::read(reader)?;
2396 let b_htlc_key = Readable::read(reader)?;
2397 let delayed_payment_key = Readable::read(reader)?;
2398 let per_commitment_point = Readable::read(reader)?;
2399 let feerate_per_kw: u32 = Readable::read(reader)?;
2401 let htlcs_len: u64 = Readable::read(reader)?;
2402 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2403 for _ in 0..htlcs_len {
2404 let htlc = read_htlc_in_commitment!();
2405 let sigs = match <u8 as Readable>::read(reader)? {
2407 1 => Some(Readable::read(reader)?),
2408 _ => return Err(DecodeError::InvalidValue),
2410 htlcs.push((htlc, sigs, Readable::read(reader)?));
2415 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2422 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2425 Some(read_local_tx!())
2427 _ => return Err(DecodeError::InvalidValue),
2429 let current_local_commitment_tx = read_local_tx!();
2431 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2432 let current_local_commitment_number = <U48 as Readable>::read(reader)?.0;
2434 let payment_preimages_len: u64 = Readable::read(reader)?;
2435 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2436 for _ in 0..payment_preimages_len {
2437 let preimage: PaymentPreimage = Readable::read(reader)?;
2438 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2439 if let Some(_) = payment_preimages.insert(hash, preimage) {
2440 return Err(DecodeError::InvalidValue);
2444 let pending_htlcs_updated_len: u64 = Readable::read(reader)?;
2445 let mut pending_htlcs_updated = Vec::with_capacity(cmp::min(pending_htlcs_updated_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2446 for _ in 0..pending_htlcs_updated_len {
2447 pending_htlcs_updated.push(Readable::read(reader)?);
2450 let pending_events_len: u64 = Readable::read(reader)?;
2451 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<events::Event>()));
2452 for _ in 0..pending_events_len {
2453 if let Some(event) = MaybeReadable::read(reader)? {
2454 pending_events.push(event);
2458 let last_block_hash: BlockHash = Readable::read(reader)?;
2460 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2461 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2462 for _ in 0..waiting_threshold_conf_len {
2463 let height_target = Readable::read(reader)?;
2464 let events_len: u64 = Readable::read(reader)?;
2465 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2466 for _ in 0..events_len {
2467 let ev = match <u8 as Readable>::read(reader)? {
2469 let htlc_source = Readable::read(reader)?;
2470 let hash = Readable::read(reader)?;
2471 OnchainEvent::HTLCUpdate {
2472 htlc_update: (htlc_source, hash)
2476 let descriptor = Readable::read(reader)?;
2477 OnchainEvent::MaturingOutput {
2481 _ => return Err(DecodeError::InvalidValue),
2485 onchain_events_waiting_threshold_conf.insert(height_target, events);
2488 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2489 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>>())));
2490 for _ in 0..outputs_to_watch_len {
2491 let txid = Readable::read(reader)?;
2492 let outputs_len: u64 = Readable::read(reader)?;
2493 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2494 for _ in 0..outputs_len {
2495 outputs.push(Readable::read(reader)?);
2497 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2498 return Err(DecodeError::InvalidValue);
2501 let onchain_tx_handler = Readable::read(reader)?;
2503 let lockdown_from_offchain = Readable::read(reader)?;
2504 let local_tx_signed = Readable::read(reader)?;
2506 Ok((last_block_hash.clone(), ChannelMonitor {
2508 commitment_transaction_number_obscure_factor,
2511 broadcasted_local_revokable_script,
2512 remote_payment_script,
2517 current_remote_commitment_txid,
2518 prev_remote_commitment_txid,
2521 funding_redeemscript,
2522 channel_value_satoshis,
2523 their_cur_revocation_points,
2528 remote_claimable_outpoints,
2529 remote_commitment_txn_on_chain,
2530 remote_hash_commitment_number,
2532 prev_local_signed_commitment_tx,
2533 current_local_commitment_tx,
2534 current_remote_commitment_number,
2535 current_local_commitment_number,
2538 pending_htlcs_updated,
2541 onchain_events_waiting_threshold_conf,
2546 lockdown_from_offchain,
2550 secp_ctx: Secp256k1::new(),
2557 use bitcoin::blockdata::script::{Script, Builder};
2558 use bitcoin::blockdata::opcodes;
2559 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2560 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2561 use bitcoin::util::bip143;
2562 use bitcoin::hashes::Hash;
2563 use bitcoin::hashes::sha256::Hash as Sha256;
2564 use bitcoin::hashes::hex::FromHex;
2565 use bitcoin::hash_types::Txid;
2567 use chain::transaction::OutPoint;
2568 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2569 use ln::channelmonitor::ChannelMonitor;
2570 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2572 use ln::chan_utils::{HTLCOutputInCommitment, LocalCommitmentTransaction};
2573 use util::test_utils::TestLogger;
2574 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2575 use bitcoin::secp256k1::Secp256k1;
2577 use chain::keysinterface::InMemoryChannelKeys;
2580 fn test_prune_preimages() {
2581 let secp_ctx = Secp256k1::new();
2582 let logger = Arc::new(TestLogger::new());
2584 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2585 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2587 let mut preimages = Vec::new();
2590 let preimage = PaymentPreimage([i; 32]);
2591 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2592 preimages.push((preimage, hash));
2596 macro_rules! preimages_slice_to_htlc_outputs {
2597 ($preimages_slice: expr) => {
2599 let mut res = Vec::new();
2600 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2601 res.push((HTLCOutputInCommitment {
2605 payment_hash: preimage.1.clone(),
2606 transaction_output_index: Some(idx as u32),
2613 macro_rules! preimages_to_local_htlcs {
2614 ($preimages_slice: expr) => {
2616 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2617 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2623 macro_rules! test_preimages_exist {
2624 ($preimages_slice: expr, $monitor: expr) => {
2625 for preimage in $preimages_slice {
2626 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2631 let keys = InMemoryChannelKeys::new(
2633 SecretKey::from_slice(&[41; 32]).unwrap(),
2634 SecretKey::from_slice(&[41; 32]).unwrap(),
2635 SecretKey::from_slice(&[41; 32]).unwrap(),
2636 SecretKey::from_slice(&[41; 32]).unwrap(),
2637 SecretKey::from_slice(&[41; 32]).unwrap(),
2643 // Prune with one old state and a local commitment tx holding a few overlaps with the
2645 let mut monitor = ChannelMonitor::new(keys,
2646 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2647 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2648 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2649 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2650 10, Script::new(), 46, 0, LocalCommitmentTransaction::dummy());
2652 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2653 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2654 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2655 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2656 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2657 for &(ref preimage, ref hash) in preimages.iter() {
2658 monitor.provide_payment_preimage(hash, preimage);
2661 // Now provide a secret, pruning preimages 10-15
2662 let mut secret = [0; 32];
2663 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2664 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2665 assert_eq!(monitor.payment_preimages.len(), 15);
2666 test_preimages_exist!(&preimages[0..10], monitor);
2667 test_preimages_exist!(&preimages[15..20], monitor);
2669 // Now provide a further secret, pruning preimages 15-17
2670 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2671 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2672 assert_eq!(monitor.payment_preimages.len(), 13);
2673 test_preimages_exist!(&preimages[0..10], monitor);
2674 test_preimages_exist!(&preimages[17..20], monitor);
2676 // Now update local commitment tx info, pruning only element 18 as we still care about the
2677 // previous commitment tx's preimages too
2678 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2679 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2680 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2681 assert_eq!(monitor.payment_preimages.len(), 12);
2682 test_preimages_exist!(&preimages[0..10], monitor);
2683 test_preimages_exist!(&preimages[18..20], monitor);
2685 // But if we do it again, we'll prune 5-10
2686 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2687 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2688 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2689 assert_eq!(monitor.payment_preimages.len(), 5);
2690 test_preimages_exist!(&preimages[0..5], monitor);
2694 fn test_claim_txn_weight_computation() {
2695 // We test Claim txn weight, knowing that we want expected weigth and
2696 // not actual case to avoid sigs and time-lock delays hell variances.
2698 let secp_ctx = Secp256k1::new();
2699 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2700 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2701 let mut sum_actual_sigs = 0;
2703 macro_rules! sign_input {
2704 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2705 let htlc = HTLCOutputInCommitment {
2706 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2708 cltv_expiry: 2 << 16,
2709 payment_hash: PaymentHash([1; 32]),
2710 transaction_output_index: Some($idx),
2712 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2713 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2714 let sig = secp_ctx.sign(&sighash, &privkey);
2715 $input.witness.push(sig.serialize_der().to_vec());
2716 $input.witness[0].push(SigHashType::All as u8);
2717 sum_actual_sigs += $input.witness[0].len();
2718 if *$input_type == InputDescriptors::RevokedOutput {
2719 $input.witness.push(vec!(1));
2720 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2721 $input.witness.push(pubkey.clone().serialize().to_vec());
2722 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2723 $input.witness.push(vec![0]);
2725 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2727 $input.witness.push(redeem_script.into_bytes());
2728 println!("witness[0] {}", $input.witness[0].len());
2729 println!("witness[1] {}", $input.witness[1].len());
2730 println!("witness[2] {}", $input.witness[2].len());
2734 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2735 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2737 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2738 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2740 claim_tx.input.push(TxIn {
2741 previous_output: BitcoinOutPoint {
2745 script_sig: Script::new(),
2746 sequence: 0xfffffffd,
2747 witness: Vec::new(),
2750 claim_tx.output.push(TxOut {
2751 script_pubkey: script_pubkey.clone(),
2754 let base_weight = claim_tx.get_weight();
2755 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2756 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2757 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2758 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2760 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));
2762 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2763 claim_tx.input.clear();
2764 sum_actual_sigs = 0;
2766 claim_tx.input.push(TxIn {
2767 previous_output: BitcoinOutPoint {
2771 script_sig: Script::new(),
2772 sequence: 0xfffffffd,
2773 witness: Vec::new(),
2776 let base_weight = claim_tx.get_weight();
2777 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2778 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2779 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2780 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2782 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));
2784 // Justice tx with 1 revoked HTLC-Success tx output
2785 claim_tx.input.clear();
2786 sum_actual_sigs = 0;
2787 claim_tx.input.push(TxIn {
2788 previous_output: BitcoinOutPoint {
2792 script_sig: Script::new(),
2793 sequence: 0xfffffffd,
2794 witness: Vec::new(),
2796 let base_weight = claim_tx.get_weight();
2797 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2798 let inputs_des = vec![InputDescriptors::RevokedOutput];
2799 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2800 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2802 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));
2805 // Further testing is done in the ChannelManager integration tests.