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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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 /// An event to be processed by the ChannelManager.
153 pub enum MonitorEvent {
154 /// A monitor event containing an HTLCUpdate.
155 HTLCEvent(HTLCUpdate),
157 /// A monitor event that the Channel's commitment transaction was broadcasted.
158 CommitmentTxBroadcasted(OutPoint),
161 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
162 /// forward channel and from which info are needed to update HTLC in a backward channel.
163 #[derive(Clone, PartialEq)]
164 pub struct HTLCUpdate {
165 pub(super) payment_hash: PaymentHash,
166 pub(super) payment_preimage: Option<PaymentPreimage>,
167 pub(super) source: HTLCSource
169 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
171 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
172 /// watchtower or watch our own channels.
174 /// Note that you must provide your own key by which to refer to channels.
176 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
177 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
178 /// index by a PublicKey which is required to sign any updates.
180 /// If you're using this for local monitoring of your own channels, you probably want to use
181 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
182 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref>
183 where T::Target: BroadcasterInterface,
184 F::Target: FeeEstimator,
186 C::Target: ChainWatchInterface,
189 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
196 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>
197 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
198 where T::Target: BroadcasterInterface,
199 F::Target: FeeEstimator,
201 C::Target: ChainWatchInterface,
203 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[usize]) {
204 let block_hash = header.bitcoin_hash();
206 let mut monitors = self.monitors.lock().unwrap();
207 for monitor in monitors.values_mut() {
208 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
210 for (ref txid, ref outputs) in txn_outputs {
211 for (idx, output) in outputs.iter().enumerate() {
212 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
219 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
220 let block_hash = header.bitcoin_hash();
221 let mut monitors = self.monitors.lock().unwrap();
222 for monitor in monitors.values_mut() {
223 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
228 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>
229 where T::Target: BroadcasterInterface,
230 F::Target: FeeEstimator,
232 C::Target: ChainWatchInterface,
234 /// Creates a new object which can be used to monitor several channels given the chain
235 /// interface with which to register to receive notifications.
236 pub fn new(chain_monitor: C, broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C> {
237 let res = SimpleManyChannelMonitor {
238 monitors: Mutex::new(HashMap::new()),
242 fee_estimator: feeest,
248 /// Adds or updates the monitor which monitors the channel referred to by the given key.
249 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
250 let mut monitors = self.monitors.lock().unwrap();
251 let entry = match monitors.entry(key) {
252 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
253 hash_map::Entry::Vacant(e) => e,
256 let funding_txo = monitor.get_funding_txo();
257 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
258 self.chain_monitor.install_watch_tx(&funding_txo.0.txid, &funding_txo.1);
259 self.chain_monitor.install_watch_outpoint((funding_txo.0.txid, funding_txo.0.index as u32), &funding_txo.1);
260 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
261 for (idx, script) in outputs.iter().enumerate() {
262 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
266 entry.insert(monitor);
270 /// Updates the monitor which monitors the channel referred to by the given key.
271 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
272 let mut monitors = self.monitors.lock().unwrap();
273 match monitors.get_mut(&key) {
274 Some(orig_monitor) => {
275 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
276 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
278 None => Err(MonitorUpdateError("No such monitor registered"))
283 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>
284 where T::Target: BroadcasterInterface,
285 F::Target: FeeEstimator,
287 C::Target: ChainWatchInterface,
289 type Keys = ChanSigner;
291 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
292 match self.add_monitor_by_key(funding_txo, monitor) {
294 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
298 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
299 match self.update_monitor_by_key(funding_txo, update) {
301 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
305 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
306 let mut pending_monitor_events = Vec::new();
307 for chan in self.monitors.lock().unwrap().values_mut() {
308 pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events());
310 pending_monitor_events
314 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>
315 where T::Target: BroadcasterInterface,
316 F::Target: FeeEstimator,
318 C::Target: ChainWatchInterface,
320 fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
321 let mut pending_events = Vec::new();
322 for chan in self.monitors.lock().unwrap().values_mut() {
323 pending_events.append(&mut chan.get_and_clear_pending_events());
329 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
330 /// instead claiming it in its own individual transaction.
331 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
332 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
333 /// HTLC-Success transaction.
334 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
335 /// transaction confirmed (and we use it in a few more, equivalent, places).
336 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
337 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
338 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
339 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
340 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
341 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
342 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
343 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
344 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
345 /// accurate block height.
346 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
347 /// with at worst this delay, so we are not only using this value as a mercy for them but also
348 /// us as a safeguard to delay with enough time.
349 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
350 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
351 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
352 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
353 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
354 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
355 /// keeping bumping another claim tx to solve the outpoint.
356 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
357 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
358 /// refuse to accept a new HTLC.
360 /// This is used for a few separate purposes:
361 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
362 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
364 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
365 /// condition with the above), we will fail this HTLC without telling the user we received it,
366 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
367 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
369 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
370 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
372 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
373 /// in a race condition between the user connecting a block (which would fail it) and the user
374 /// providing us the preimage (which would claim it).
376 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
377 /// end up force-closing the channel on us to claim it.
378 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
380 #[derive(Clone, PartialEq)]
381 struct LocalSignedTx {
382 /// txid of the transaction in tx, just used to make comparison faster
384 revocation_key: PublicKey,
385 a_htlc_key: PublicKey,
386 b_htlc_key: PublicKey,
387 delayed_payment_key: PublicKey,
388 per_commitment_point: PublicKey,
390 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
393 /// We use this to track remote commitment transactions and htlcs outputs and
394 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
396 struct RemoteCommitmentTransaction {
397 remote_delayed_payment_base_key: PublicKey,
398 remote_htlc_base_key: PublicKey,
399 on_remote_tx_csv: u16,
400 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
403 impl Writeable for RemoteCommitmentTransaction {
404 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
405 self.remote_delayed_payment_base_key.write(w)?;
406 self.remote_htlc_base_key.write(w)?;
407 w.write_all(&byte_utils::be16_to_array(self.on_remote_tx_csv))?;
408 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
409 for (ref txid, ref htlcs) in self.per_htlc.iter() {
410 w.write_all(&txid[..])?;
411 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
412 for &ref htlc in htlcs.iter() {
419 impl Readable for RemoteCommitmentTransaction {
420 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
421 let remote_commitment_transaction = {
422 let remote_delayed_payment_base_key = Readable::read(r)?;
423 let remote_htlc_base_key = Readable::read(r)?;
424 let on_remote_tx_csv: u16 = Readable::read(r)?;
425 let per_htlc_len: u64 = Readable::read(r)?;
426 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
427 for _ in 0..per_htlc_len {
428 let txid: Txid = Readable::read(r)?;
429 let htlcs_count: u64 = Readable::read(r)?;
430 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
431 for _ in 0..htlcs_count {
432 let htlc = Readable::read(r)?;
435 if let Some(_) = per_htlc.insert(txid, htlcs) {
436 return Err(DecodeError::InvalidValue);
439 RemoteCommitmentTransaction {
440 remote_delayed_payment_base_key,
441 remote_htlc_base_key,
446 Ok(remote_commitment_transaction)
450 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
451 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
452 /// a new bumped one in case of lenghty confirmation delay
453 #[derive(Clone, PartialEq)]
454 pub(crate) enum InputMaterial {
456 per_commitment_point: PublicKey,
457 remote_delayed_payment_base_key: PublicKey,
458 remote_htlc_base_key: PublicKey,
459 per_commitment_key: SecretKey,
460 input_descriptor: InputDescriptors,
462 htlc: Option<HTLCOutputInCommitment>,
463 on_remote_tx_csv: u16,
466 per_commitment_point: PublicKey,
467 remote_delayed_payment_base_key: PublicKey,
468 remote_htlc_base_key: PublicKey,
469 preimage: Option<PaymentPreimage>,
470 htlc: HTLCOutputInCommitment
473 preimage: Option<PaymentPreimage>,
477 funding_redeemscript: Script,
481 impl Writeable for InputMaterial {
482 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
484 &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} => {
485 writer.write_all(&[0; 1])?;
486 per_commitment_point.write(writer)?;
487 remote_delayed_payment_base_key.write(writer)?;
488 remote_htlc_base_key.write(writer)?;
489 writer.write_all(&per_commitment_key[..])?;
490 input_descriptor.write(writer)?;
491 writer.write_all(&byte_utils::be64_to_array(*amount))?;
493 on_remote_tx_csv.write(writer)?;
495 &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc} => {
496 writer.write_all(&[1; 1])?;
497 per_commitment_point.write(writer)?;
498 remote_delayed_payment_base_key.write(writer)?;
499 remote_htlc_base_key.write(writer)?;
500 preimage.write(writer)?;
503 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
504 writer.write_all(&[2; 1])?;
505 preimage.write(writer)?;
506 writer.write_all(&byte_utils::be64_to_array(*amount))?;
508 &InputMaterial::Funding { ref funding_redeemscript } => {
509 writer.write_all(&[3; 1])?;
510 funding_redeemscript.write(writer)?;
517 impl Readable for InputMaterial {
518 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
519 let input_material = match <u8 as Readable>::read(reader)? {
521 let per_commitment_point = Readable::read(reader)?;
522 let remote_delayed_payment_base_key = Readable::read(reader)?;
523 let remote_htlc_base_key = Readable::read(reader)?;
524 let per_commitment_key = Readable::read(reader)?;
525 let input_descriptor = Readable::read(reader)?;
526 let amount = Readable::read(reader)?;
527 let htlc = Readable::read(reader)?;
528 let on_remote_tx_csv = Readable::read(reader)?;
529 InputMaterial::Revoked {
530 per_commitment_point,
531 remote_delayed_payment_base_key,
532 remote_htlc_base_key,
541 let per_commitment_point = Readable::read(reader)?;
542 let remote_delayed_payment_base_key = Readable::read(reader)?;
543 let remote_htlc_base_key = Readable::read(reader)?;
544 let preimage = Readable::read(reader)?;
545 let htlc = Readable::read(reader)?;
546 InputMaterial::RemoteHTLC {
547 per_commitment_point,
548 remote_delayed_payment_base_key,
549 remote_htlc_base_key,
555 let preimage = Readable::read(reader)?;
556 let amount = Readable::read(reader)?;
557 InputMaterial::LocalHTLC {
563 InputMaterial::Funding {
564 funding_redeemscript: Readable::read(reader)?,
567 _ => return Err(DecodeError::InvalidValue),
573 /// ClaimRequest is a descriptor structure to communicate between detection
574 /// and reaction module. They are generated by ChannelMonitor while parsing
575 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
576 /// is responsible for opportunistic aggregation, selecting and enforcing
577 /// bumping logic, building and signing transactions.
578 pub(crate) struct ClaimRequest {
579 // Block height before which claiming is exclusive to one party,
580 // after reaching it, claiming may be contentious.
581 pub(crate) absolute_timelock: u32,
582 // Timeout tx must have nLocktime set which means aggregating multiple
583 // ones must take the higher nLocktime among them to satisfy all of them.
584 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
585 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
586 // Do simplify we mark them as non-aggregable.
587 pub(crate) aggregable: bool,
588 // Basic bitcoin outpoint (txid, vout)
589 pub(crate) outpoint: BitcoinOutPoint,
590 // Following outpoint type, set of data needed to generate transaction digest
591 // and satisfy witness program.
592 pub(crate) witness_data: InputMaterial
595 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
596 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
597 #[derive(Clone, PartialEq)]
599 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
600 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
601 /// only win from it, so it's never an OnchainEvent
603 htlc_update: (HTLCSource, PaymentHash),
606 descriptor: SpendableOutputDescriptor,
610 const SERIALIZATION_VERSION: u8 = 1;
611 const MIN_SERIALIZATION_VERSION: u8 = 1;
613 #[cfg_attr(test, derive(PartialEq))]
615 pub(super) enum ChannelMonitorUpdateStep {
616 LatestLocalCommitmentTXInfo {
617 commitment_tx: LocalCommitmentTransaction,
618 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
620 LatestRemoteCommitmentTXInfo {
621 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
622 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
623 commitment_number: u64,
624 their_revocation_point: PublicKey,
627 payment_preimage: PaymentPreimage,
633 /// Used to indicate that the no future updates will occur, and likely that the latest local
634 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
636 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
637 /// think we've fallen behind!
638 should_broadcast: bool,
642 impl Writeable for ChannelMonitorUpdateStep {
643 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
645 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
647 commitment_tx.write(w)?;
648 (htlc_outputs.len() as u64).write(w)?;
649 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
655 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
657 unsigned_commitment_tx.write(w)?;
658 commitment_number.write(w)?;
659 their_revocation_point.write(w)?;
660 (htlc_outputs.len() as u64).write(w)?;
661 for &(ref output, ref source) in htlc_outputs.iter() {
663 source.as_ref().map(|b| b.as_ref()).write(w)?;
666 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
668 payment_preimage.write(w)?;
670 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
675 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
677 should_broadcast.write(w)?;
683 impl Readable for ChannelMonitorUpdateStep {
684 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
685 match Readable::read(r)? {
687 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
688 commitment_tx: Readable::read(r)?,
690 let len: u64 = Readable::read(r)?;
691 let mut res = Vec::new();
693 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
700 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
701 unsigned_commitment_tx: Readable::read(r)?,
702 commitment_number: Readable::read(r)?,
703 their_revocation_point: Readable::read(r)?,
705 let len: u64 = Readable::read(r)?;
706 let mut res = Vec::new();
708 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
715 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
716 payment_preimage: Readable::read(r)?,
720 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
721 idx: Readable::read(r)?,
722 secret: Readable::read(r)?,
726 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
727 should_broadcast: Readable::read(r)?
730 _ => Err(DecodeError::InvalidValue),
735 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
736 /// on-chain transactions to ensure no loss of funds occurs.
738 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
739 /// information and are actively monitoring the chain.
741 /// Pending Events or updated HTLCs which have not yet been read out by
742 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
743 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
744 /// gotten are fully handled before re-serializing the new state.
745 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
746 latest_update_id: u64,
747 commitment_transaction_number_obscure_factor: u64,
749 destination_script: Script,
750 broadcasted_local_revokable_script: Option<(Script, PublicKey, PublicKey)>,
751 remote_payment_script: Script,
752 shutdown_script: Script,
755 funding_info: (OutPoint, Script),
756 current_remote_commitment_txid: Option<Txid>,
757 prev_remote_commitment_txid: Option<Txid>,
759 remote_tx_cache: RemoteCommitmentTransaction,
760 funding_redeemscript: Script,
761 channel_value_satoshis: u64,
762 // first is the idx of the first of the two revocation points
763 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
765 on_local_tx_csv: u16,
767 commitment_secrets: CounterpartyCommitmentSecrets,
768 remote_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
769 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
770 /// Nor can we figure out their commitment numbers without the commitment transaction they are
771 /// spending. Thus, in order to claim them via revocation key, we track all the remote
772 /// commitment transactions which we find on-chain, mapping them to the commitment number which
773 /// can be used to derive the revocation key and claim the transactions.
774 remote_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
775 /// Cache used to make pruning of payment_preimages faster.
776 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
777 /// remote transactions (ie should remain pretty small).
778 /// Serialized to disk but should generally not be sent to Watchtowers.
779 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
781 // We store two local commitment transactions to avoid any race conditions where we may update
782 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
783 // various monitors for one channel being out of sync, and us broadcasting a local
784 // transaction for which we have deleted claim information on some watchtowers.
785 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
786 current_local_commitment_tx: LocalSignedTx,
788 // Used just for ChannelManager to make sure it has the latest channel data during
790 current_remote_commitment_number: u64,
791 // Used just for ChannelManager to make sure it has the latest channel data during
793 current_local_commitment_number: u64,
795 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
797 pending_monitor_events: Vec<MonitorEvent>,
798 pending_events: Vec<events::Event>,
800 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
801 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
802 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
803 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
805 // If we get serialized out and re-read, we need to make sure that the chain monitoring
806 // interface knows about the TXOs that we want to be notified of spends of. We could probably
807 // be smart and derive them from the above storage fields, but its much simpler and more
808 // Obviously Correct (tm) if we just keep track of them explicitly.
809 outputs_to_watch: HashMap<Txid, Vec<Script>>,
812 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
814 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
816 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
817 // channel has been force-closed. After this is set, no further local commitment transaction
818 // updates may occur, and we panic!() if one is provided.
819 lockdown_from_offchain: bool,
821 // Set once we've signed a local commitment transaction and handed it over to our
822 // OnchainTxHandler. After this is set, no future updates to our local commitment transactions
823 // may occur, and we fail any such monitor updates.
824 local_tx_signed: bool,
826 // We simply modify last_block_hash in Channel's block_connected so that serialization is
827 // consistent but hopefully the users' copy handles block_connected in a consistent way.
828 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
829 // their last_block_hash from its state and not based on updated copies that didn't run through
830 // the full block_connected).
831 pub(crate) last_block_hash: BlockHash,
832 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
835 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
836 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
837 /// events to it, while also taking any add/update_monitor events and passing them to some remote
840 /// In general, you must always have at least one local copy in memory, which must never fail to
841 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
842 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
843 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
844 /// taking any further action such as writing the current state to disk. This should likely be
845 /// accomplished via panic!() or abort().
847 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
848 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
849 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
850 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
852 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
853 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
854 /// than calling these methods directly, the user should register implementors as listeners to the
855 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
856 /// all registered listeners in one go.
857 pub trait ManyChannelMonitor: Send + Sync {
858 /// The concrete type which signs for transactions and provides access to our channel public
860 type Keys: ChannelKeys;
862 /// Adds a monitor for the given `funding_txo`.
864 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
865 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
866 /// callbacks with the funding transaction, or any spends of it.
868 /// Further, the implementer must also ensure that each output returned in
869 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
870 /// any spends of any of the outputs.
872 /// Any spends of outputs which should have been registered which aren't passed to
873 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
874 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
876 /// Updates a monitor for the given `funding_txo`.
878 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
879 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
880 /// callbacks with the funding transaction, or any spends of it.
882 /// Further, the implementer must also ensure that each output returned in
883 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
884 /// any spends of any of the outputs.
886 /// Any spends of outputs which should have been registered which aren't passed to
887 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
888 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
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_monitor_events() for each ChannelMonitor and return
896 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent>;
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_monitor_events != other.pending_monitor_events ||
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_monitor_events.len() as u64))?;
1084 for event in self.pending_monitor_events.iter() {
1086 MonitorEvent::HTLCEvent(upd) => {
1090 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
1094 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1095 for event in self.pending_events.iter() {
1096 event.write(writer)?;
1099 self.last_block_hash.write(writer)?;
1101 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1102 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1103 writer.write_all(&byte_utils::be32_to_array(**target))?;
1104 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1105 for ev in events.iter() {
1107 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1109 htlc_update.0.write(writer)?;
1110 htlc_update.1.write(writer)?;
1112 OnchainEvent::MaturingOutput { ref descriptor } => {
1114 descriptor.write(writer)?;
1120 (self.outputs_to_watch.len() as u64).write(writer)?;
1121 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1122 txid.write(writer)?;
1123 (output_scripts.len() as u64).write(writer)?;
1124 for script in output_scripts.iter() {
1125 script.write(writer)?;
1128 self.onchain_tx_handler.write(writer)?;
1130 self.lockdown_from_offchain.write(writer)?;
1131 self.local_tx_signed.write(writer)?;
1137 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1138 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1139 on_remote_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1140 remote_htlc_base_key: &PublicKey, remote_delayed_payment_base_key: &PublicKey,
1141 on_local_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1142 commitment_transaction_number_obscure_factor: u64,
1143 initial_local_commitment_tx: LocalCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1145 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1146 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1147 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1148 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1149 let remote_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1151 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() };
1153 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_local_tx_csv);
1155 let local_tx_sequence = initial_local_commitment_tx.unsigned_tx.input[0].sequence as u64;
1156 let local_tx_locktime = initial_local_commitment_tx.unsigned_tx.lock_time as u64;
1157 let local_commitment_tx = LocalSignedTx {
1158 txid: initial_local_commitment_tx.txid(),
1159 revocation_key: initial_local_commitment_tx.local_keys.revocation_key,
1160 a_htlc_key: initial_local_commitment_tx.local_keys.a_htlc_key,
1161 b_htlc_key: initial_local_commitment_tx.local_keys.b_htlc_key,
1162 delayed_payment_key: initial_local_commitment_tx.local_keys.a_delayed_payment_key,
1163 per_commitment_point: initial_local_commitment_tx.local_keys.per_commitment_point,
1164 feerate_per_kw: initial_local_commitment_tx.feerate_per_kw,
1165 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1167 // Returning a monitor error before updating tracking points means in case of using
1168 // a concurrent watchtower implementation for same channel, if this one doesn't
1169 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1170 // for which you want to spend outputs. We're NOT robust again this scenario right
1171 // now but we should consider it later.
1172 onchain_tx_handler.provide_latest_local_tx(initial_local_commitment_tx).unwrap();
1175 latest_update_id: 0,
1176 commitment_transaction_number_obscure_factor,
1178 destination_script: destination_script.clone(),
1179 broadcasted_local_revokable_script: None,
1180 remote_payment_script,
1185 current_remote_commitment_txid: None,
1186 prev_remote_commitment_txid: None,
1189 funding_redeemscript,
1190 channel_value_satoshis: channel_value_satoshis,
1191 their_cur_revocation_points: None,
1195 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1196 remote_claimable_outpoints: HashMap::new(),
1197 remote_commitment_txn_on_chain: HashMap::new(),
1198 remote_hash_commitment_number: HashMap::new(),
1200 prev_local_signed_commitment_tx: None,
1201 current_local_commitment_tx: local_commitment_tx,
1202 current_remote_commitment_number: 1 << 48,
1203 current_local_commitment_number: 0xffff_ffff_ffff - ((((local_tx_sequence & 0xffffff) << 3*8) | (local_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1205 payment_preimages: HashMap::new(),
1206 pending_monitor_events: Vec::new(),
1207 pending_events: Vec::new(),
1209 onchain_events_waiting_threshold_conf: HashMap::new(),
1210 outputs_to_watch: HashMap::new(),
1214 lockdown_from_offchain: false,
1215 local_tx_signed: false,
1217 last_block_hash: Default::default(),
1218 secp_ctx: Secp256k1::new(),
1222 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1223 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1224 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1225 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1226 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1227 return Err(MonitorUpdateError("Previous secret did not match new one"));
1230 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1231 // events for now-revoked/fulfilled HTLCs.
1232 if let Some(txid) = self.prev_remote_commitment_txid.take() {
1233 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1238 if !self.payment_preimages.is_empty() {
1239 let cur_local_signed_commitment_tx = &self.current_local_commitment_tx;
1240 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1241 let min_idx = self.get_min_seen_secret();
1242 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1244 self.payment_preimages.retain(|&k, _| {
1245 for &(ref htlc, _, _) in cur_local_signed_commitment_tx.htlc_outputs.iter() {
1246 if k == htlc.payment_hash {
1250 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1251 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1252 if k == htlc.payment_hash {
1257 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1264 remote_hash_commitment_number.remove(&k);
1273 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1274 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1275 /// possibly future revocation/preimage information) to claim outputs where possible.
1276 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1277 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 {
1278 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1279 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1280 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1282 for &(ref htlc, _) in &htlc_outputs {
1283 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1286 let new_txid = unsigned_commitment_tx.txid();
1287 log_trace!(logger, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1288 log_trace!(logger, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1289 self.prev_remote_commitment_txid = self.current_remote_commitment_txid.take();
1290 self.current_remote_commitment_txid = Some(new_txid);
1291 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1292 self.current_remote_commitment_number = commitment_number;
1293 //TODO: Merge this into the other per-remote-transaction output storage stuff
1294 match self.their_cur_revocation_points {
1295 Some(old_points) => {
1296 if old_points.0 == commitment_number + 1 {
1297 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1298 } else if old_points.0 == commitment_number + 2 {
1299 if let Some(old_second_point) = old_points.2 {
1300 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1302 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1305 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1309 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1312 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1313 for htlc in htlc_outputs {
1314 if htlc.0.transaction_output_index.is_some() {
1318 self.remote_tx_cache.per_htlc.insert(new_txid, htlcs);
1321 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1322 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1323 /// is important that any clones of this channel monitor (including remote clones) by kept
1324 /// up-to-date as our local commitment transaction is updated.
1325 /// Panics if set_on_local_tx_csv has never been called.
1326 pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1327 if self.local_tx_signed {
1328 return Err(MonitorUpdateError("A local commitment tx has already been signed, no new local commitment txn can be sent to our counterparty"));
1330 let txid = commitment_tx.txid();
1331 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1332 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1333 let mut new_local_commitment_tx = LocalSignedTx {
1335 revocation_key: commitment_tx.local_keys.revocation_key,
1336 a_htlc_key: commitment_tx.local_keys.a_htlc_key,
1337 b_htlc_key: commitment_tx.local_keys.b_htlc_key,
1338 delayed_payment_key: commitment_tx.local_keys.a_delayed_payment_key,
1339 per_commitment_point: commitment_tx.local_keys.per_commitment_point,
1340 feerate_per_kw: commitment_tx.feerate_per_kw,
1341 htlc_outputs: htlc_outputs,
1343 // Returning a monitor error before updating tracking points means in case of using
1344 // a concurrent watchtower implementation for same channel, if this one doesn't
1345 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1346 // for which you want to spend outputs. We're NOT robust again this scenario right
1347 // now but we should consider it later.
1348 if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx) {
1349 return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1351 self.current_local_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1352 mem::swap(&mut new_local_commitment_tx, &mut self.current_local_commitment_tx);
1353 self.prev_local_signed_commitment_tx = Some(new_local_commitment_tx);
1357 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1358 /// commitment_tx_infos which contain the payment hash have been revoked.
1359 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1360 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1363 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1364 where B::Target: BroadcasterInterface,
1367 for tx in self.get_latest_local_commitment_txn(logger).iter() {
1368 broadcaster.broadcast_transaction(tx);
1370 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1373 /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
1374 pub(super) fn update_monitor_ooo<L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, logger: &L) -> Result<(), MonitorUpdateError> where L::Target: Logger {
1375 for update in updates.updates.drain(..) {
1377 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1378 if self.lockdown_from_offchain { panic!(); }
1379 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1381 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1382 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1383 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1384 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1385 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1386 self.provide_secret(idx, secret)?,
1387 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
1390 self.latest_update_id = updates.update_id;
1394 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1397 /// panics if the given update is not the next update by update_id.
1398 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1399 where B::Target: BroadcasterInterface,
1402 if self.latest_update_id + 1 != updates.update_id {
1403 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1405 for update in updates.updates.drain(..) {
1407 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1408 if self.lockdown_from_offchain { panic!(); }
1409 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1411 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1412 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1413 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1414 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1415 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1416 self.provide_secret(idx, secret)?,
1417 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1418 self.lockdown_from_offchain = true;
1419 if should_broadcast {
1420 self.broadcast_latest_local_commitment_txn(broadcaster, logger);
1422 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");
1427 self.latest_update_id = updates.update_id;
1431 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1433 pub fn get_latest_update_id(&self) -> u64 {
1434 self.latest_update_id
1437 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1438 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1442 /// Gets a list of txids, with their output scripts (in the order they appear in the
1443 /// transaction), which we must learn about spends of via block_connected().
1444 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1445 &self.outputs_to_watch
1448 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1449 /// Generally useful when deserializing as during normal operation the return values of
1450 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1451 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1452 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1453 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1454 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1455 for (idx, output) in outputs.iter().enumerate() {
1456 res.push(((*txid).clone(), idx as u32, output));
1462 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1463 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_monitor_events().
1464 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1465 let mut ret = Vec::new();
1466 mem::swap(&mut ret, &mut self.pending_monitor_events);
1470 /// Gets the list of pending events which were generated by previous actions, clearing the list
1473 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1474 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1475 /// no internal locking in ChannelMonitors.
1476 pub fn get_and_clear_pending_events(&mut self) -> Vec<events::Event> {
1477 let mut ret = Vec::new();
1478 mem::swap(&mut ret, &mut self.pending_events);
1482 /// Can only fail if idx is < get_min_seen_secret
1483 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1484 self.commitment_secrets.get_secret(idx)
1487 pub(super) fn get_min_seen_secret(&self) -> u64 {
1488 self.commitment_secrets.get_min_seen_secret()
1491 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1492 self.current_remote_commitment_number
1495 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1496 self.current_local_commitment_number
1499 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1500 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1501 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1502 /// HTLC-Success/HTLC-Timeout transactions.
1503 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1504 /// revoked remote commitment tx
1505 fn check_spend_remote_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1506 // Most secp and related errors trying to create keys means we have no hope of constructing
1507 // a spend transaction...so we return no transactions to broadcast
1508 let mut claimable_outpoints = Vec::new();
1509 let mut watch_outputs = Vec::new();
1511 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1512 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1514 macro_rules! ignore_error {
1515 ( $thing : expr ) => {
1518 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1523 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);
1524 if commitment_number >= self.get_min_seen_secret() {
1525 let secret = self.get_secret(commitment_number).unwrap();
1526 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1527 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1528 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1529 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));
1531 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.remote_tx_cache.on_remote_tx_csv, &delayed_key);
1532 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1534 // First, process non-htlc outputs (to_local & to_remote)
1535 for (idx, outp) in tx.output.iter().enumerate() {
1536 if outp.script_pubkey == revokeable_p2wsh {
1537 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};
1538 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});
1542 // Then, try to find revoked htlc outputs
1543 if let Some(ref per_commitment_data) = per_commitment_option {
1544 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1545 if let Some(transaction_output_index) = htlc.transaction_output_index {
1546 if transaction_output_index as usize >= tx.output.len() ||
1547 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1548 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1550 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};
1551 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1556 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1557 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1558 // We're definitely a remote commitment transaction!
1559 log_trace!(logger, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1560 watch_outputs.append(&mut tx.output.clone());
1561 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1563 macro_rules! check_htlc_fails {
1564 ($txid: expr, $commitment_tx: expr) => {
1565 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1566 for &(ref htlc, ref source_option) in outpoints.iter() {
1567 if let &Some(ref source) = source_option {
1568 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1569 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1570 hash_map::Entry::Occupied(mut entry) => {
1571 let e = entry.get_mut();
1572 e.retain(|ref event| {
1574 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1575 return htlc_update.0 != **source
1580 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1582 hash_map::Entry::Vacant(entry) => {
1583 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1591 if let Some(ref txid) = self.current_remote_commitment_txid {
1592 check_htlc_fails!(txid, "current");
1594 if let Some(ref txid) = self.prev_remote_commitment_txid {
1595 check_htlc_fails!(txid, "remote");
1597 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1599 } else if let Some(per_commitment_data) = per_commitment_option {
1600 // While this isn't useful yet, there is a potential race where if a counterparty
1601 // revokes a state at the same time as the commitment transaction for that state is
1602 // confirmed, and the watchtower receives the block before the user, the user could
1603 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1604 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1605 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1607 watch_outputs.append(&mut tx.output.clone());
1608 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1610 log_trace!(logger, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1612 macro_rules! check_htlc_fails {
1613 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1614 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1615 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1616 if let &Some(ref source) = source_option {
1617 // Check if the HTLC is present in the commitment transaction that was
1618 // broadcast, but not if it was below the dust limit, which we should
1619 // fail backwards immediately as there is no way for us to learn the
1620 // payment_preimage.
1621 // Note that if the dust limit were allowed to change between
1622 // commitment transactions we'd want to be check whether *any*
1623 // broadcastable commitment transaction has the HTLC in it, but it
1624 // cannot currently change after channel initialization, so we don't
1626 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1627 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1631 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);
1632 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1633 hash_map::Entry::Occupied(mut entry) => {
1634 let e = entry.get_mut();
1635 e.retain(|ref event| {
1637 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1638 return htlc_update.0 != **source
1643 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1645 hash_map::Entry::Vacant(entry) => {
1646 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1654 if let Some(ref txid) = self.current_remote_commitment_txid {
1655 check_htlc_fails!(txid, "current", 'current_loop);
1657 if let Some(ref txid) = self.prev_remote_commitment_txid {
1658 check_htlc_fails!(txid, "previous", 'prev_loop);
1661 if let Some(revocation_points) = self.their_cur_revocation_points {
1662 let revocation_point_option =
1663 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1664 else if let Some(point) = revocation_points.2.as_ref() {
1665 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1667 if let Some(revocation_point) = revocation_point_option {
1668 self.remote_payment_script = {
1669 // Note that the Network here is ignored as we immediately drop the address for the
1670 // script_pubkey version
1671 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1672 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1675 // Then, try to find htlc outputs
1676 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1677 if let Some(transaction_output_index) = htlc.transaction_output_index {
1678 if transaction_output_index as usize >= tx.output.len() ||
1679 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1680 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1682 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1683 let aggregable = if !htlc.offered { false } else { true };
1684 if preimage.is_some() || !htlc.offered {
1685 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() };
1686 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1693 (claimable_outpoints, (commitment_txid, watch_outputs))
1696 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1697 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 {
1698 let htlc_txid = tx.txid();
1699 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1700 return (Vec::new(), None)
1703 macro_rules! ignore_error {
1704 ( $thing : expr ) => {
1707 Err(_) => return (Vec::new(), None)
1712 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1713 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1714 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1716 log_trace!(logger, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1717 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 };
1718 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 });
1719 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1722 fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1723 let mut claim_requests = Vec::with_capacity(local_tx.htlc_outputs.len());
1724 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1726 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.on_local_tx_csv, &local_tx.delayed_payment_key);
1727 let broadcasted_local_revokable_script = Some((redeemscript.to_v0_p2wsh(), local_tx.per_commitment_point.clone(), local_tx.revocation_key.clone()));
1729 for &(ref htlc, _, _) in local_tx.htlc_outputs.iter() {
1730 if let Some(transaction_output_index) = htlc.transaction_output_index {
1731 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: local_tx.txid, vout: transaction_output_index as u32 },
1732 witness_data: InputMaterial::LocalHTLC {
1733 preimage: if !htlc.offered {
1734 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1735 Some(preimage.clone())
1737 // We can't build an HTLC-Success transaction without the preimage
1741 amount: htlc.amount_msat,
1743 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1747 (claim_requests, watch_outputs, broadcasted_local_revokable_script)
1750 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1751 /// revoked using data in local_claimable_outpoints.
1752 /// Should not be used if check_spend_revoked_transaction succeeds.
1753 fn check_spend_local_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1754 let commitment_txid = tx.txid();
1755 let mut claim_requests = Vec::new();
1756 let mut watch_outputs = Vec::new();
1758 macro_rules! wait_threshold_conf {
1759 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1760 log_trace!(logger, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1761 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1762 hash_map::Entry::Occupied(mut entry) => {
1763 let e = entry.get_mut();
1764 e.retain(|ref event| {
1766 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1767 return htlc_update.0 != $source
1772 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1774 hash_map::Entry::Vacant(entry) => {
1775 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1781 macro_rules! append_onchain_update {
1782 ($updates: expr) => {
1783 claim_requests = $updates.0;
1784 watch_outputs.append(&mut $updates.1);
1785 self.broadcasted_local_revokable_script = $updates.2;
1789 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1790 let mut is_local_tx = false;
1792 if self.current_local_commitment_tx.txid == commitment_txid {
1794 log_trace!(logger, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1795 let mut res = self.broadcast_by_local_state(tx, &self.current_local_commitment_tx);
1796 append_onchain_update!(res);
1797 } else if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1798 if local_tx.txid == commitment_txid {
1800 log_trace!(logger, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1801 let mut res = self.broadcast_by_local_state(tx, local_tx);
1802 append_onchain_update!(res);
1806 macro_rules! fail_dust_htlcs_after_threshold_conf {
1807 ($local_tx: expr) => {
1808 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1809 if htlc.transaction_output_index.is_none() {
1810 if let &Some(ref source) = source {
1811 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1819 fail_dust_htlcs_after_threshold_conf!(self.current_local_commitment_tx);
1820 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1821 fail_dust_htlcs_after_threshold_conf!(local_tx);
1825 (claim_requests, (commitment_txid, watch_outputs))
1828 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1829 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1830 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1831 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1832 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1833 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1834 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1835 /// out-of-band the other node operator to coordinate with him if option is available to you.
1836 /// In any-case, choice is up to the user.
1837 pub fn get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1838 log_trace!(logger, "Getting signed latest local commitment transaction!");
1839 self.local_tx_signed = true;
1840 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1841 let txid = commitment_tx.txid();
1842 let mut res = vec![commitment_tx];
1843 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1844 if let Some(vout) = htlc.0.transaction_output_index {
1845 let preimage = if !htlc.0.offered {
1846 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1847 // We can't build an HTLC-Success transaction without the preimage
1851 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1852 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1857 // 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.
1858 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1864 /// Unsafe test-only version of get_latest_local_commitment_txn used by our test framework
1865 /// to bypass LocalCommitmentTransaction state update lockdown after signature and generate
1866 /// revoked commitment transaction.
1867 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1868 pub fn unsafe_get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1869 log_trace!(logger, "Getting signed copy of latest local commitment transaction!");
1870 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_local_tx(&self.funding_redeemscript) {
1871 let txid = commitment_tx.txid();
1872 let mut res = vec![commitment_tx];
1873 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1874 if let Some(vout) = htlc.0.transaction_output_index {
1875 let preimage = if !htlc.0.offered {
1876 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1877 // We can't build an HTLC-Success transaction without the preimage
1881 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1882 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1892 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1893 /// ChainListener::block_connected.
1894 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1895 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1897 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>)>
1898 where B::Target: BroadcasterInterface,
1899 F::Target: FeeEstimator,
1902 for tx in txn_matched {
1903 let mut output_val = 0;
1904 for out in tx.output.iter() {
1905 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1906 output_val += out.value;
1907 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1911 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1912 let mut watch_outputs = Vec::new();
1913 let mut claimable_outpoints = Vec::new();
1914 for tx in txn_matched {
1915 if tx.input.len() == 1 {
1916 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1917 // commitment transactions and HTLC transactions will all only ever have one input,
1918 // which is an easy way to filter out any potential non-matching txn for lazy
1920 let prevout = &tx.input[0].previous_output;
1921 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1922 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1923 let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height, &logger);
1924 if !new_outputs.1.is_empty() {
1925 watch_outputs.push(new_outputs);
1927 if new_outpoints.is_empty() {
1928 let (mut new_outpoints, new_outputs) = self.check_spend_local_transaction(&tx, height, &logger);
1929 if !new_outputs.1.is_empty() {
1930 watch_outputs.push(new_outputs);
1932 claimable_outpoints.append(&mut new_outpoints);
1934 claimable_outpoints.append(&mut new_outpoints);
1937 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1938 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height, &logger);
1939 claimable_outpoints.append(&mut new_outpoints);
1940 if let Some(new_outputs) = new_outputs_option {
1941 watch_outputs.push(new_outputs);
1946 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1947 // can also be resolved in a few other ways which can have more than one output. Thus,
1948 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1949 self.is_resolving_htlc_output(&tx, height, &logger);
1951 self.is_paying_spendable_output(&tx, height, &logger);
1953 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1954 if should_broadcast {
1955 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() }});
1957 if should_broadcast {
1958 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1959 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1960 self.local_tx_signed = true;
1961 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_local_state(&commitment_tx, &self.current_local_commitment_tx);
1962 if !new_outputs.is_empty() {
1963 watch_outputs.push((self.current_local_commitment_tx.txid.clone(), new_outputs));
1965 claimable_outpoints.append(&mut new_outpoints);
1968 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1971 OnchainEvent::HTLCUpdate { htlc_update } => {
1972 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1973 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1974 payment_hash: htlc_update.1,
1975 payment_preimage: None,
1976 source: htlc_update.0,
1979 OnchainEvent::MaturingOutput { descriptor } => {
1980 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1981 self.pending_events.push(events::Event::SpendableOutputs {
1982 outputs: vec![descriptor]
1989 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1991 self.last_block_hash = block_hash.clone();
1992 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1993 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1999 fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)
2000 where B::Target: BroadcasterInterface,
2001 F::Target: FeeEstimator,
2004 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
2005 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
2007 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2008 //- maturing spendable output has transaction paying us has been disconnected
2011 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2013 self.last_block_hash = block_hash.clone();
2016 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2017 // We need to consider all HTLCs which are:
2018 // * in any unrevoked remote commitment transaction, as they could broadcast said
2019 // transactions and we'd end up in a race, or
2020 // * are in our latest local commitment transaction, as this is the thing we will
2021 // broadcast if we go on-chain.
2022 // Note that we consider HTLCs which were below dust threshold here - while they don't
2023 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2024 // to the source, and if we don't fail the channel we will have to ensure that the next
2025 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2026 // easier to just fail the channel as this case should be rare enough anyway.
2027 macro_rules! scan_commitment {
2028 ($htlcs: expr, $local_tx: expr) => {
2029 for ref htlc in $htlcs {
2030 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2031 // chain with enough room to claim the HTLC without our counterparty being able to
2032 // time out the HTLC first.
2033 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2034 // concern is being able to claim the corresponding inbound HTLC (on another
2035 // channel) before it expires. In fact, we don't even really care if our
2036 // counterparty here claims such an outbound HTLC after it expired as long as we
2037 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2038 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2039 // we give ourselves a few blocks of headroom after expiration before going
2040 // on-chain for an expired HTLC.
2041 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2042 // from us until we've reached the point where we go on-chain with the
2043 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2044 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2045 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2046 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2047 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2048 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2049 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2050 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2051 // The final, above, condition is checked for statically in channelmanager
2052 // with CHECK_CLTV_EXPIRY_SANITY_2.
2053 let htlc_outbound = $local_tx == htlc.offered;
2054 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2055 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2056 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2063 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2065 if let Some(ref txid) = self.current_remote_commitment_txid {
2066 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2067 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2070 if let Some(ref txid) = self.prev_remote_commitment_txid {
2071 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2072 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2079 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2080 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2081 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2082 'outer_loop: for input in &tx.input {
2083 let mut payment_data = None;
2084 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2085 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2086 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2087 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2089 macro_rules! log_claim {
2090 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2091 // We found the output in question, but aren't failing it backwards
2092 // as we have no corresponding source and no valid remote commitment txid
2093 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2094 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2095 let outbound_htlc = $local_tx == $htlc.offered;
2096 if ($local_tx && revocation_sig_claim) ||
2097 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2098 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2099 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2100 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2101 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2103 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2104 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2105 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2106 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2111 macro_rules! check_htlc_valid_remote {
2112 ($remote_txid: expr, $htlc_output: expr) => {
2113 if let Some(txid) = $remote_txid {
2114 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2115 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2116 if let &Some(ref source) = pending_source {
2117 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2118 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2127 macro_rules! scan_commitment {
2128 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2129 for (ref htlc_output, source_option) in $htlcs {
2130 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2131 if let Some(ref source) = source_option {
2132 log_claim!($tx_info, $local_tx, htlc_output, true);
2133 // We have a resolution of an HTLC either from one of our latest
2134 // local commitment transactions or an unrevoked remote commitment
2135 // transaction. This implies we either learned a preimage, the HTLC
2136 // has timed out, or we screwed up. In any case, we should now
2137 // resolve the source HTLC with the original sender.
2138 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2139 } else if !$local_tx {
2140 check_htlc_valid_remote!(self.current_remote_commitment_txid, htlc_output);
2141 if payment_data.is_none() {
2142 check_htlc_valid_remote!(self.prev_remote_commitment_txid, htlc_output);
2145 if payment_data.is_none() {
2146 log_claim!($tx_info, $local_tx, htlc_output, false);
2147 continue 'outer_loop;
2154 if input.previous_output.txid == self.current_local_commitment_tx.txid {
2155 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2156 "our latest local commitment tx", true);
2158 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2159 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2160 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2161 "our previous local commitment tx", true);
2164 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2165 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2166 "remote commitment tx", false);
2169 // Check that scan_commitment, above, decided there is some source worth relaying an
2170 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2171 if let Some((source, payment_hash)) = payment_data {
2172 let mut payment_preimage = PaymentPreimage([0; 32]);
2173 if accepted_preimage_claim {
2174 if !self.pending_monitor_events.iter().any(
2175 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2176 payment_preimage.0.copy_from_slice(&input.witness[3]);
2177 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2179 payment_preimage: Some(payment_preimage),
2183 } else if offered_preimage_claim {
2184 if !self.pending_monitor_events.iter().any(
2185 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2186 upd.source == source
2188 payment_preimage.0.copy_from_slice(&input.witness[1]);
2189 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2191 payment_preimage: Some(payment_preimage),
2196 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);
2197 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2198 hash_map::Entry::Occupied(mut entry) => {
2199 let e = entry.get_mut();
2200 e.retain(|ref event| {
2202 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2203 return htlc_update.0 != source
2208 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2210 hash_map::Entry::Vacant(entry) => {
2211 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2219 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2220 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2221 let mut spendable_output = None;
2222 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2223 if outp.script_pubkey == self.destination_script {
2224 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2225 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2226 output: outp.clone(),
2229 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2230 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2231 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2232 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2233 per_commitment_point: broadcasted_local_revokable_script.1,
2234 to_self_delay: self.on_local_tx_csv,
2235 output: outp.clone(),
2236 key_derivation_params: self.keys.key_derivation_params(),
2237 remote_revocation_pubkey: broadcasted_local_revokable_script.2.clone(),
2241 } else if self.remote_payment_script == outp.script_pubkey {
2242 spendable_output = Some(SpendableOutputDescriptor::StaticOutputRemotePayment {
2243 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2244 output: outp.clone(),
2245 key_derivation_params: self.keys.key_derivation_params(),
2248 } else if outp.script_pubkey == self.shutdown_script {
2249 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2250 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2251 output: outp.clone(),
2255 if let Some(spendable_output) = spendable_output {
2256 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2257 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2258 hash_map::Entry::Occupied(mut entry) => {
2259 let e = entry.get_mut();
2260 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2262 hash_map::Entry::Vacant(entry) => {
2263 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2270 const MAX_ALLOC_SIZE: usize = 64*1024;
2272 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2273 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2274 macro_rules! unwrap_obj {
2278 Err(_) => return Err(DecodeError::InvalidValue),
2283 let _ver: u8 = Readable::read(reader)?;
2284 let min_ver: u8 = Readable::read(reader)?;
2285 if min_ver > SERIALIZATION_VERSION {
2286 return Err(DecodeError::UnknownVersion);
2289 let latest_update_id: u64 = Readable::read(reader)?;
2290 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2292 let destination_script = Readable::read(reader)?;
2293 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2295 let revokable_address = Readable::read(reader)?;
2296 let per_commitment_point = Readable::read(reader)?;
2297 let revokable_script = Readable::read(reader)?;
2298 Some((revokable_address, per_commitment_point, revokable_script))
2301 _ => return Err(DecodeError::InvalidValue),
2303 let remote_payment_script = Readable::read(reader)?;
2304 let shutdown_script = Readable::read(reader)?;
2306 let keys = Readable::read(reader)?;
2307 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2308 // barely-init'd ChannelMonitors that we can't do anything with.
2309 let outpoint = OutPoint {
2310 txid: Readable::read(reader)?,
2311 index: Readable::read(reader)?,
2313 let funding_info = (outpoint, Readable::read(reader)?);
2314 let current_remote_commitment_txid = Readable::read(reader)?;
2315 let prev_remote_commitment_txid = Readable::read(reader)?;
2317 let remote_tx_cache = Readable::read(reader)?;
2318 let funding_redeemscript = Readable::read(reader)?;
2319 let channel_value_satoshis = Readable::read(reader)?;
2321 let their_cur_revocation_points = {
2322 let first_idx = <U48 as Readable>::read(reader)?.0;
2326 let first_point = Readable::read(reader)?;
2327 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2328 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2329 Some((first_idx, first_point, None))
2331 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2336 let on_local_tx_csv: u16 = Readable::read(reader)?;
2338 let commitment_secrets = Readable::read(reader)?;
2340 macro_rules! read_htlc_in_commitment {
2343 let offered: bool = Readable::read(reader)?;
2344 let amount_msat: u64 = Readable::read(reader)?;
2345 let cltv_expiry: u32 = Readable::read(reader)?;
2346 let payment_hash: PaymentHash = Readable::read(reader)?;
2347 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2349 HTLCOutputInCommitment {
2350 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2356 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2357 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2358 for _ in 0..remote_claimable_outpoints_len {
2359 let txid: Txid = Readable::read(reader)?;
2360 let htlcs_count: u64 = Readable::read(reader)?;
2361 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2362 for _ in 0..htlcs_count {
2363 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2365 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2366 return Err(DecodeError::InvalidValue);
2370 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2371 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2372 for _ in 0..remote_commitment_txn_on_chain_len {
2373 let txid: Txid = Readable::read(reader)?;
2374 let commitment_number = <U48 as Readable>::read(reader)?.0;
2375 let outputs_count = <u64 as Readable>::read(reader)?;
2376 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2377 for _ in 0..outputs_count {
2378 outputs.push(Readable::read(reader)?);
2380 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2381 return Err(DecodeError::InvalidValue);
2385 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2386 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2387 for _ in 0..remote_hash_commitment_number_len {
2388 let payment_hash: PaymentHash = Readable::read(reader)?;
2389 let commitment_number = <U48 as Readable>::read(reader)?.0;
2390 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2391 return Err(DecodeError::InvalidValue);
2395 macro_rules! read_local_tx {
2398 let txid = Readable::read(reader)?;
2399 let revocation_key = Readable::read(reader)?;
2400 let a_htlc_key = Readable::read(reader)?;
2401 let b_htlc_key = Readable::read(reader)?;
2402 let delayed_payment_key = Readable::read(reader)?;
2403 let per_commitment_point = Readable::read(reader)?;
2404 let feerate_per_kw: u32 = Readable::read(reader)?;
2406 let htlcs_len: u64 = Readable::read(reader)?;
2407 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2408 for _ in 0..htlcs_len {
2409 let htlc = read_htlc_in_commitment!();
2410 let sigs = match <u8 as Readable>::read(reader)? {
2412 1 => Some(Readable::read(reader)?),
2413 _ => return Err(DecodeError::InvalidValue),
2415 htlcs.push((htlc, sigs, Readable::read(reader)?));
2420 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2427 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2430 Some(read_local_tx!())
2432 _ => return Err(DecodeError::InvalidValue),
2434 let current_local_commitment_tx = read_local_tx!();
2436 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2437 let current_local_commitment_number = <U48 as Readable>::read(reader)?.0;
2439 let payment_preimages_len: u64 = Readable::read(reader)?;
2440 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2441 for _ in 0..payment_preimages_len {
2442 let preimage: PaymentPreimage = Readable::read(reader)?;
2443 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2444 if let Some(_) = payment_preimages.insert(hash, preimage) {
2445 return Err(DecodeError::InvalidValue);
2449 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2450 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2451 for _ in 0..pending_monitor_events_len {
2452 let ev = match <u8 as Readable>::read(reader)? {
2453 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2454 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2455 _ => return Err(DecodeError::InvalidValue)
2457 pending_monitor_events.push(ev);
2460 let pending_events_len: u64 = Readable::read(reader)?;
2461 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<events::Event>()));
2462 for _ in 0..pending_events_len {
2463 if let Some(event) = MaybeReadable::read(reader)? {
2464 pending_events.push(event);
2468 let last_block_hash: BlockHash = Readable::read(reader)?;
2470 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2471 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2472 for _ in 0..waiting_threshold_conf_len {
2473 let height_target = Readable::read(reader)?;
2474 let events_len: u64 = Readable::read(reader)?;
2475 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2476 for _ in 0..events_len {
2477 let ev = match <u8 as Readable>::read(reader)? {
2479 let htlc_source = Readable::read(reader)?;
2480 let hash = Readable::read(reader)?;
2481 OnchainEvent::HTLCUpdate {
2482 htlc_update: (htlc_source, hash)
2486 let descriptor = Readable::read(reader)?;
2487 OnchainEvent::MaturingOutput {
2491 _ => return Err(DecodeError::InvalidValue),
2495 onchain_events_waiting_threshold_conf.insert(height_target, events);
2498 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2499 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>>())));
2500 for _ in 0..outputs_to_watch_len {
2501 let txid = Readable::read(reader)?;
2502 let outputs_len: u64 = Readable::read(reader)?;
2503 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2504 for _ in 0..outputs_len {
2505 outputs.push(Readable::read(reader)?);
2507 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2508 return Err(DecodeError::InvalidValue);
2511 let onchain_tx_handler = Readable::read(reader)?;
2513 let lockdown_from_offchain = Readable::read(reader)?;
2514 let local_tx_signed = Readable::read(reader)?;
2516 Ok((last_block_hash.clone(), ChannelMonitor {
2518 commitment_transaction_number_obscure_factor,
2521 broadcasted_local_revokable_script,
2522 remote_payment_script,
2527 current_remote_commitment_txid,
2528 prev_remote_commitment_txid,
2531 funding_redeemscript,
2532 channel_value_satoshis,
2533 their_cur_revocation_points,
2538 remote_claimable_outpoints,
2539 remote_commitment_txn_on_chain,
2540 remote_hash_commitment_number,
2542 prev_local_signed_commitment_tx,
2543 current_local_commitment_tx,
2544 current_remote_commitment_number,
2545 current_local_commitment_number,
2548 pending_monitor_events,
2551 onchain_events_waiting_threshold_conf,
2556 lockdown_from_offchain,
2560 secp_ctx: Secp256k1::new(),
2567 use bitcoin::blockdata::script::{Script, Builder};
2568 use bitcoin::blockdata::opcodes;
2569 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2570 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2571 use bitcoin::util::bip143;
2572 use bitcoin::hashes::Hash;
2573 use bitcoin::hashes::sha256::Hash as Sha256;
2574 use bitcoin::hashes::hex::FromHex;
2575 use bitcoin::hash_types::Txid;
2577 use chain::transaction::OutPoint;
2578 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2579 use ln::channelmonitor::ChannelMonitor;
2580 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2582 use ln::chan_utils::{HTLCOutputInCommitment, LocalCommitmentTransaction};
2583 use util::test_utils::TestLogger;
2584 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2585 use bitcoin::secp256k1::Secp256k1;
2587 use chain::keysinterface::InMemoryChannelKeys;
2590 fn test_prune_preimages() {
2591 let secp_ctx = Secp256k1::new();
2592 let logger = Arc::new(TestLogger::new());
2594 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2595 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2597 let mut preimages = Vec::new();
2600 let preimage = PaymentPreimage([i; 32]);
2601 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2602 preimages.push((preimage, hash));
2606 macro_rules! preimages_slice_to_htlc_outputs {
2607 ($preimages_slice: expr) => {
2609 let mut res = Vec::new();
2610 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2611 res.push((HTLCOutputInCommitment {
2615 payment_hash: preimage.1.clone(),
2616 transaction_output_index: Some(idx as u32),
2623 macro_rules! preimages_to_local_htlcs {
2624 ($preimages_slice: expr) => {
2626 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2627 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2633 macro_rules! test_preimages_exist {
2634 ($preimages_slice: expr, $monitor: expr) => {
2635 for preimage in $preimages_slice {
2636 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2641 let keys = InMemoryChannelKeys::new(
2643 SecretKey::from_slice(&[41; 32]).unwrap(),
2644 SecretKey::from_slice(&[41; 32]).unwrap(),
2645 SecretKey::from_slice(&[41; 32]).unwrap(),
2646 SecretKey::from_slice(&[41; 32]).unwrap(),
2647 SecretKey::from_slice(&[41; 32]).unwrap(),
2653 // Prune with one old state and a local commitment tx holding a few overlaps with the
2655 let mut monitor = ChannelMonitor::new(keys,
2656 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2657 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2658 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2659 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2660 10, Script::new(), 46, 0, LocalCommitmentTransaction::dummy());
2662 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2663 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2664 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2665 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2666 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2667 for &(ref preimage, ref hash) in preimages.iter() {
2668 monitor.provide_payment_preimage(hash, preimage);
2671 // Now provide a secret, pruning preimages 10-15
2672 let mut secret = [0; 32];
2673 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2674 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2675 assert_eq!(monitor.payment_preimages.len(), 15);
2676 test_preimages_exist!(&preimages[0..10], monitor);
2677 test_preimages_exist!(&preimages[15..20], monitor);
2679 // Now provide a further secret, pruning preimages 15-17
2680 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2681 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2682 assert_eq!(monitor.payment_preimages.len(), 13);
2683 test_preimages_exist!(&preimages[0..10], monitor);
2684 test_preimages_exist!(&preimages[17..20], monitor);
2686 // Now update local commitment tx info, pruning only element 18 as we still care about the
2687 // previous commitment tx's preimages too
2688 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2689 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2690 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2691 assert_eq!(monitor.payment_preimages.len(), 12);
2692 test_preimages_exist!(&preimages[0..10], monitor);
2693 test_preimages_exist!(&preimages[18..20], monitor);
2695 // But if we do it again, we'll prune 5-10
2696 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2697 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2698 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2699 assert_eq!(monitor.payment_preimages.len(), 5);
2700 test_preimages_exist!(&preimages[0..5], monitor);
2704 fn test_claim_txn_weight_computation() {
2705 // We test Claim txn weight, knowing that we want expected weigth and
2706 // not actual case to avoid sigs and time-lock delays hell variances.
2708 let secp_ctx = Secp256k1::new();
2709 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2710 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2711 let mut sum_actual_sigs = 0;
2713 macro_rules! sign_input {
2714 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2715 let htlc = HTLCOutputInCommitment {
2716 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2718 cltv_expiry: 2 << 16,
2719 payment_hash: PaymentHash([1; 32]),
2720 transaction_output_index: Some($idx),
2722 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2723 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2724 let sig = secp_ctx.sign(&sighash, &privkey);
2725 $input.witness.push(sig.serialize_der().to_vec());
2726 $input.witness[0].push(SigHashType::All as u8);
2727 sum_actual_sigs += $input.witness[0].len();
2728 if *$input_type == InputDescriptors::RevokedOutput {
2729 $input.witness.push(vec!(1));
2730 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2731 $input.witness.push(pubkey.clone().serialize().to_vec());
2732 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2733 $input.witness.push(vec![0]);
2735 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2737 $input.witness.push(redeem_script.into_bytes());
2738 println!("witness[0] {}", $input.witness[0].len());
2739 println!("witness[1] {}", $input.witness[1].len());
2740 println!("witness[2] {}", $input.witness[2].len());
2744 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2745 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2747 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2748 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2750 claim_tx.input.push(TxIn {
2751 previous_output: BitcoinOutPoint {
2755 script_sig: Script::new(),
2756 sequence: 0xfffffffd,
2757 witness: Vec::new(),
2760 claim_tx.output.push(TxOut {
2761 script_pubkey: script_pubkey.clone(),
2764 let base_weight = claim_tx.get_weight();
2765 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2766 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2767 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2768 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2770 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));
2772 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2773 claim_tx.input.clear();
2774 sum_actual_sigs = 0;
2776 claim_tx.input.push(TxIn {
2777 previous_output: BitcoinOutPoint {
2781 script_sig: Script::new(),
2782 sequence: 0xfffffffd,
2783 witness: Vec::new(),
2786 let base_weight = claim_tx.get_weight();
2787 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2788 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2789 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2790 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2792 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));
2794 // Justice tx with 1 revoked HTLC-Success tx output
2795 claim_tx.input.clear();
2796 sum_actual_sigs = 0;
2797 claim_tx.input.push(TxIn {
2798 previous_output: BitcoinOutPoint {
2802 script_sig: Script::new(),
2803 sequence: 0xfffffffd,
2804 witness: Vec::new(),
2806 let base_weight = claim_tx.get_weight();
2807 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2808 let inputs_des = vec![InputDescriptors::RevokedOutput];
2809 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2810 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2812 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));
2815 // Further testing is done in the ChannelManager integration tests.