1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see ManyChannelMonitor for more.
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{TxOut,Transaction};
25 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
26 use bitcoin::blockdata::script::{Script, Builder};
27 use bitcoin::blockdata::opcodes;
28 use bitcoin::consensus::encode;
30 use bitcoin::hashes::Hash;
31 use bitcoin::hashes::sha256::Hash as Sha256;
32 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
34 use bitcoin::secp256k1::{Secp256k1,Signature};
35 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
36 use bitcoin::secp256k1;
38 use ln::msgs::DecodeError;
40 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HolderCommitmentTransaction, HTLCType};
41 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
42 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
43 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator};
44 use chain::transaction::OutPoint;
45 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
46 use util::logger::Logger;
47 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
48 use util::{byte_utils, events};
49 use util::events::Event;
51 use std::collections::{HashMap, hash_map};
53 use std::{hash,cmp, mem};
57 /// An update generated by the underlying Channel itself which contains some new information the
58 /// ChannelMonitor should be made aware of.
59 #[cfg_attr(test, derive(PartialEq))]
62 pub struct ChannelMonitorUpdate {
63 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
64 /// The sequence number of this update. Updates *must* be replayed in-order according to this
65 /// sequence number (and updates may panic if they are not). The update_id values are strictly
66 /// increasing and increase by one for each new update.
68 /// This sequence number is also used to track up to which points updates which returned
69 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
70 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
74 impl Writeable for ChannelMonitorUpdate {
75 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
76 self.update_id.write(w)?;
77 (self.updates.len() as u64).write(w)?;
78 for update_step in self.updates.iter() {
79 update_step.write(w)?;
84 impl Readable for ChannelMonitorUpdate {
85 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
86 let update_id: u64 = Readable::read(r)?;
87 let len: u64 = Readable::read(r)?;
88 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
90 updates.push(Readable::read(r)?);
92 Ok(Self { update_id, updates })
96 /// An error enum representing a failure to persist a channel monitor update.
98 pub enum ChannelMonitorUpdateErr {
99 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
100 /// our state failed, but is expected to succeed at some point in the future).
102 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
103 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
104 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
105 /// restore the channel to an operational state.
107 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
108 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
109 /// writing out the latest ChannelManager state.
111 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
112 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
113 /// to claim it on this channel) and those updates must be applied wherever they can be. At
114 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
115 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
116 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
119 /// Note that even if updates made after TemporaryFailure succeed you must still call
120 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
123 /// Note that the update being processed here will not be replayed for you when you call
124 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
125 /// with the persisted ChannelMonitor on your own local disk prior to returning a
126 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
127 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
130 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
131 /// remote location (with local copies persisted immediately), it is anticipated that all
132 /// updates will return TemporaryFailure until the remote copies could be updated.
134 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
135 /// different watchtower and cannot update with all watchtowers that were previously informed
136 /// of this channel). This will force-close the channel in question (which will generate one
137 /// final ChannelMonitorUpdate which must be delivered to at least one ChannelMonitor copy).
139 /// Should also be used to indicate a failure to update the local persisted copy of the channel
144 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
145 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
146 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
148 /// Contains a human-readable error message.
150 pub struct MonitorUpdateError(pub &'static str);
152 /// An event to be processed by the ChannelManager.
154 pub enum MonitorEvent {
155 /// A monitor event containing an HTLCUpdate.
156 HTLCEvent(HTLCUpdate),
158 /// A monitor event that the Channel's commitment transaction was broadcasted.
159 CommitmentTxBroadcasted(OutPoint),
162 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
163 /// forward channel and from which info are needed to update HTLC in a backward channel.
164 #[derive(Clone, PartialEq)]
165 pub struct HTLCUpdate {
166 pub(super) payment_hash: PaymentHash,
167 pub(super) payment_preimage: Option<PaymentPreimage>,
168 pub(super) source: HTLCSource
170 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
172 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
173 /// watchtower or watch our own channels.
175 /// Note that you must provide your own key by which to refer to channels.
177 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
178 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
179 /// index by a PublicKey which is required to sign any updates.
181 /// If you're using this for local monitoring of your own channels, you probably want to use
182 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
184 /// (C-not exported) due to an unconstrained generic in `Key`
185 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref>
186 where T::Target: BroadcasterInterface,
187 F::Target: FeeEstimator,
189 C::Target: ChainWatchInterface,
192 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
199 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>
200 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
201 where T::Target: BroadcasterInterface,
202 F::Target: FeeEstimator,
204 C::Target: ChainWatchInterface,
206 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[usize]) {
207 let block_hash = header.block_hash();
209 let mut monitors = self.monitors.lock().unwrap();
210 for monitor in monitors.values_mut() {
211 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
213 for (ref txid, ref outputs) in txn_outputs {
214 for (idx, output) in outputs.iter().enumerate() {
215 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
222 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
223 let block_hash = header.block_hash();
224 let mut monitors = self.monitors.lock().unwrap();
225 for monitor in monitors.values_mut() {
226 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
231 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>
232 where T::Target: BroadcasterInterface,
233 F::Target: FeeEstimator,
235 C::Target: ChainWatchInterface,
237 /// Creates a new object which can be used to monitor several channels given the chain
238 /// interface with which to register to receive notifications.
239 pub fn new(chain_monitor: C, broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C> {
240 let res = SimpleManyChannelMonitor {
241 monitors: Mutex::new(HashMap::new()),
245 fee_estimator: feeest,
251 /// Adds or updates the monitor which monitors the channel referred to by the given key.
252 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
253 let mut monitors = self.monitors.lock().unwrap();
254 let entry = match monitors.entry(key) {
255 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
256 hash_map::Entry::Vacant(e) => e,
259 let funding_txo = monitor.get_funding_txo();
260 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
261 self.chain_monitor.install_watch_tx(&funding_txo.0.txid, &funding_txo.1);
262 self.chain_monitor.install_watch_outpoint((funding_txo.0.txid, funding_txo.0.index as u32), &funding_txo.1);
263 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
264 for (idx, script) in outputs.iter().enumerate() {
265 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
269 entry.insert(monitor);
273 /// Updates the monitor which monitors the channel referred to by the given key.
274 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
275 let mut monitors = self.monitors.lock().unwrap();
276 match monitors.get_mut(&key) {
277 Some(orig_monitor) => {
278 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
279 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
281 None => Err(MonitorUpdateError("No such monitor registered"))
286 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>
287 where T::Target: BroadcasterInterface,
288 F::Target: FeeEstimator,
290 C::Target: ChainWatchInterface,
292 type Keys = ChanSigner;
294 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
295 match self.add_monitor_by_key(funding_txo, monitor) {
297 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
301 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
302 match self.update_monitor_by_key(funding_txo, update) {
304 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
308 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
309 let mut pending_monitor_events = Vec::new();
310 for chan in self.monitors.lock().unwrap().values_mut() {
311 pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events());
313 pending_monitor_events
317 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>
318 where T::Target: BroadcasterInterface,
319 F::Target: FeeEstimator,
321 C::Target: ChainWatchInterface,
323 fn get_and_clear_pending_events(&self) -> Vec<Event> {
324 let mut pending_events = Vec::new();
325 for chan in self.monitors.lock().unwrap().values_mut() {
326 pending_events.append(&mut chan.get_and_clear_pending_events());
332 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
333 /// instead claiming it in its own individual transaction.
334 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
335 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
336 /// HTLC-Success transaction.
337 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
338 /// transaction confirmed (and we use it in a few more, equivalent, places).
339 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
340 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
341 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
342 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
343 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
344 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
345 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
346 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
347 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
348 /// accurate block height.
349 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
350 /// with at worst this delay, so we are not only using this value as a mercy for them but also
351 /// us as a safeguard to delay with enough time.
352 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
353 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
354 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
355 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
356 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
357 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
358 /// keeping bumping another claim tx to solve the outpoint.
359 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
360 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
361 /// refuse to accept a new HTLC.
363 /// This is used for a few separate purposes:
364 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
365 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
367 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
368 /// condition with the above), we will fail this HTLC without telling the user we received it,
369 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
370 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
372 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
373 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
375 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
376 /// in a race condition between the user connecting a block (which would fail it) and the user
377 /// providing us the preimage (which would claim it).
379 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
380 /// end up force-closing the channel on us to claim it.
381 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
383 #[derive(Clone, PartialEq)]
384 struct HolderSignedTx {
385 /// txid of the transaction in tx, just used to make comparison faster
387 revocation_key: PublicKey,
388 a_htlc_key: PublicKey,
389 b_htlc_key: PublicKey,
390 delayed_payment_key: PublicKey,
391 per_commitment_point: PublicKey,
393 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
396 /// We use this to track counterparty commitment transactions and htlcs outputs and
397 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
399 struct CounterpartyCommitmentTransaction {
400 counterparty_delayed_payment_base_key: PublicKey,
401 counterparty_htlc_base_key: PublicKey,
402 on_counterparty_tx_csv: u16,
403 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
406 impl Writeable for CounterpartyCommitmentTransaction {
407 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
408 self.counterparty_delayed_payment_base_key.write(w)?;
409 self.counterparty_htlc_base_key.write(w)?;
410 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
411 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
412 for (ref txid, ref htlcs) in self.per_htlc.iter() {
413 w.write_all(&txid[..])?;
414 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
415 for &ref htlc in htlcs.iter() {
422 impl Readable for CounterpartyCommitmentTransaction {
423 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
424 let counterparty_commitment_transaction = {
425 let counterparty_delayed_payment_base_key = Readable::read(r)?;
426 let counterparty_htlc_base_key = Readable::read(r)?;
427 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
428 let per_htlc_len: u64 = Readable::read(r)?;
429 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
430 for _ in 0..per_htlc_len {
431 let txid: Txid = Readable::read(r)?;
432 let htlcs_count: u64 = Readable::read(r)?;
433 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
434 for _ in 0..htlcs_count {
435 let htlc = Readable::read(r)?;
438 if let Some(_) = per_htlc.insert(txid, htlcs) {
439 return Err(DecodeError::InvalidValue);
442 CounterpartyCommitmentTransaction {
443 counterparty_delayed_payment_base_key,
444 counterparty_htlc_base_key,
445 on_counterparty_tx_csv,
449 Ok(counterparty_commitment_transaction)
453 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
454 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
455 /// a new bumped one in case of lenghty confirmation delay
456 #[derive(Clone, PartialEq)]
457 pub(crate) enum InputMaterial {
459 per_commitment_point: PublicKey,
460 counterparty_delayed_payment_base_key: PublicKey,
461 counterparty_htlc_base_key: PublicKey,
462 per_commitment_key: SecretKey,
463 input_descriptor: InputDescriptors,
465 htlc: Option<HTLCOutputInCommitment>,
466 on_counterparty_tx_csv: u16,
469 per_commitment_point: PublicKey,
470 counterparty_delayed_payment_base_key: PublicKey,
471 counterparty_htlc_base_key: PublicKey,
472 preimage: Option<PaymentPreimage>,
473 htlc: HTLCOutputInCommitment
476 preimage: Option<PaymentPreimage>,
480 funding_redeemscript: Script,
484 impl Writeable for InputMaterial {
485 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
487 &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv} => {
488 writer.write_all(&[0; 1])?;
489 per_commitment_point.write(writer)?;
490 counterparty_delayed_payment_base_key.write(writer)?;
491 counterparty_htlc_base_key.write(writer)?;
492 writer.write_all(&per_commitment_key[..])?;
493 input_descriptor.write(writer)?;
494 writer.write_all(&byte_utils::be64_to_array(*amount))?;
496 on_counterparty_tx_csv.write(writer)?;
498 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
499 writer.write_all(&[1; 1])?;
500 per_commitment_point.write(writer)?;
501 counterparty_delayed_payment_base_key.write(writer)?;
502 counterparty_htlc_base_key.write(writer)?;
503 preimage.write(writer)?;
506 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
507 writer.write_all(&[2; 1])?;
508 preimage.write(writer)?;
509 writer.write_all(&byte_utils::be64_to_array(*amount))?;
511 &InputMaterial::Funding { ref funding_redeemscript } => {
512 writer.write_all(&[3; 1])?;
513 funding_redeemscript.write(writer)?;
520 impl Readable for InputMaterial {
521 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
522 let input_material = match <u8 as Readable>::read(reader)? {
524 let per_commitment_point = Readable::read(reader)?;
525 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
526 let counterparty_htlc_base_key = Readable::read(reader)?;
527 let per_commitment_key = Readable::read(reader)?;
528 let input_descriptor = Readable::read(reader)?;
529 let amount = Readable::read(reader)?;
530 let htlc = Readable::read(reader)?;
531 let on_counterparty_tx_csv = Readable::read(reader)?;
532 InputMaterial::Revoked {
533 per_commitment_point,
534 counterparty_delayed_payment_base_key,
535 counterparty_htlc_base_key,
540 on_counterparty_tx_csv
544 let per_commitment_point = Readable::read(reader)?;
545 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
546 let counterparty_htlc_base_key = Readable::read(reader)?;
547 let preimage = Readable::read(reader)?;
548 let htlc = Readable::read(reader)?;
549 InputMaterial::CounterpartyHTLC {
550 per_commitment_point,
551 counterparty_delayed_payment_base_key,
552 counterparty_htlc_base_key,
558 let preimage = Readable::read(reader)?;
559 let amount = Readable::read(reader)?;
560 InputMaterial::HolderHTLC {
566 InputMaterial::Funding {
567 funding_redeemscript: Readable::read(reader)?,
570 _ => return Err(DecodeError::InvalidValue),
576 /// ClaimRequest is a descriptor structure to communicate between detection
577 /// and reaction module. They are generated by ChannelMonitor while parsing
578 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
579 /// is responsible for opportunistic aggregation, selecting and enforcing
580 /// bumping logic, building and signing transactions.
581 pub(crate) struct ClaimRequest {
582 // Block height before which claiming is exclusive to one party,
583 // after reaching it, claiming may be contentious.
584 pub(crate) absolute_timelock: u32,
585 // Timeout tx must have nLocktime set which means aggregating multiple
586 // ones must take the higher nLocktime among them to satisfy all of them.
587 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
588 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
589 // Do simplify we mark them as non-aggregable.
590 pub(crate) aggregable: bool,
591 // Basic bitcoin outpoint (txid, vout)
592 pub(crate) outpoint: BitcoinOutPoint,
593 // Following outpoint type, set of data needed to generate transaction digest
594 // and satisfy witness program.
595 pub(crate) witness_data: InputMaterial
598 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
599 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
600 #[derive(Clone, PartialEq)]
602 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
603 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
604 /// only win from it, so it's never an OnchainEvent
606 htlc_update: (HTLCSource, PaymentHash),
609 descriptor: SpendableOutputDescriptor,
613 const SERIALIZATION_VERSION: u8 = 1;
614 const MIN_SERIALIZATION_VERSION: u8 = 1;
616 #[cfg_attr(test, derive(PartialEq))]
618 pub(super) enum ChannelMonitorUpdateStep {
619 LatestHolderCommitmentTXInfo {
620 commitment_tx: HolderCommitmentTransaction,
621 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
623 LatestCounterpartyCommitmentTXInfo {
624 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
625 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
626 commitment_number: u64,
627 their_revocation_point: PublicKey,
630 payment_preimage: PaymentPreimage,
636 /// Used to indicate that the no future updates will occur, and likely that the latest holder
637 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
639 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
640 /// think we've fallen behind!
641 should_broadcast: bool,
645 impl Writeable for ChannelMonitorUpdateStep {
646 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
648 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
650 commitment_tx.write(w)?;
651 (htlc_outputs.len() as u64).write(w)?;
652 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
658 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
660 unsigned_commitment_tx.write(w)?;
661 commitment_number.write(w)?;
662 their_revocation_point.write(w)?;
663 (htlc_outputs.len() as u64).write(w)?;
664 for &(ref output, ref source) in htlc_outputs.iter() {
666 source.as_ref().map(|b| b.as_ref()).write(w)?;
669 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
671 payment_preimage.write(w)?;
673 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
678 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
680 should_broadcast.write(w)?;
686 impl Readable for ChannelMonitorUpdateStep {
687 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
688 match Readable::read(r)? {
690 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
691 commitment_tx: Readable::read(r)?,
693 let len: u64 = Readable::read(r)?;
694 let mut res = Vec::new();
696 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
703 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
704 unsigned_commitment_tx: Readable::read(r)?,
705 commitment_number: Readable::read(r)?,
706 their_revocation_point: Readable::read(r)?,
708 let len: u64 = Readable::read(r)?;
709 let mut res = Vec::new();
711 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
718 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
719 payment_preimage: Readable::read(r)?,
723 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
724 idx: Readable::read(r)?,
725 secret: Readable::read(r)?,
729 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
730 should_broadcast: Readable::read(r)?
733 _ => Err(DecodeError::InvalidValue),
738 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
739 /// on-chain transactions to ensure no loss of funds occurs.
741 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
742 /// information and are actively monitoring the chain.
744 /// Pending Events or updated HTLCs which have not yet been read out by
745 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
746 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
747 /// gotten are fully handled before re-serializing the new state.
748 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
749 latest_update_id: u64,
750 commitment_transaction_number_obscure_factor: u64,
752 destination_script: Script,
753 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
754 counterparty_payment_script: Script,
755 shutdown_script: Script,
758 funding_info: (OutPoint, Script),
759 current_counterparty_commitment_txid: Option<Txid>,
760 prev_counterparty_commitment_txid: Option<Txid>,
762 counterparty_tx_cache: CounterpartyCommitmentTransaction,
763 funding_redeemscript: Script,
764 channel_value_satoshis: u64,
765 // first is the idx of the first of the two revocation points
766 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
768 on_holder_tx_csv: u16,
770 commitment_secrets: CounterpartyCommitmentSecrets,
771 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
772 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
773 /// Nor can we figure out their commitment numbers without the commitment transaction they are
774 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
775 /// commitment transactions which we find on-chain, mapping them to the commitment number which
776 /// can be used to derive the revocation key and claim the transactions.
777 counterparty_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
778 /// Cache used to make pruning of payment_preimages faster.
779 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
780 /// counterparty transactions (ie should remain pretty small).
781 /// Serialized to disk but should generally not be sent to Watchtowers.
782 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
784 // We store two holder commitment transactions to avoid any race conditions where we may update
785 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
786 // various monitors for one channel being out of sync, and us broadcasting a holder
787 // transaction for which we have deleted claim information on some watchtowers.
788 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
789 current_holder_commitment_tx: HolderSignedTx,
791 // Used just for ChannelManager to make sure it has the latest channel data during
793 current_counterparty_commitment_number: u64,
794 // Used just for ChannelManager to make sure it has the latest channel data during
796 current_holder_commitment_number: u64,
798 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
800 pending_monitor_events: Vec<MonitorEvent>,
801 pending_events: Vec<Event>,
803 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
804 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
805 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
806 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
808 // If we get serialized out and re-read, we need to make sure that the chain monitoring
809 // interface knows about the TXOs that we want to be notified of spends of. We could probably
810 // be smart and derive them from the above storage fields, but its much simpler and more
811 // Obviously Correct (tm) if we just keep track of them explicitly.
812 outputs_to_watch: HashMap<Txid, Vec<Script>>,
815 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
817 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
819 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
820 // channel has been force-closed. After this is set, no further holder commitment transaction
821 // updates may occur, and we panic!() if one is provided.
822 lockdown_from_offchain: bool,
824 // Set once we've signed a holder commitment transaction and handed it over to our
825 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
826 // may occur, and we fail any such monitor updates.
827 holder_tx_signed: bool,
829 // We simply modify last_block_hash in Channel's block_connected so that serialization is
830 // consistent but hopefully the users' copy handles block_connected in a consistent way.
831 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
832 // their last_block_hash from its state and not based on updated copies that didn't run through
833 // the full block_connected).
834 last_block_hash: BlockHash,
835 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
838 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
839 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
840 /// events to it, while also taking any add/update_monitor events and passing them to some remote
843 /// In general, you must always have at least one local copy in memory, which must never fail to
844 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
845 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
846 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
847 /// taking any further action such as writing the current state to disk. This should likely be
848 /// accomplished via panic!() or abort().
850 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
851 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
852 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
853 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
855 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
856 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
857 /// than calling these methods directly, the user should register implementors as listeners to the
858 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
859 /// all registered listeners in one go.
860 pub trait ManyChannelMonitor: Send + Sync {
861 /// The concrete type which signs for transactions and provides access to our channel public
863 type Keys: ChannelKeys;
865 /// Adds a monitor for the given `funding_txo`.
867 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
868 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
869 /// callbacks with the funding transaction, or any spends of it.
871 /// Further, the implementer must also ensure that each output returned in
872 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
873 /// any spends of any of the outputs.
875 /// Any spends of outputs which should have been registered which aren't passed to
876 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
877 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<Self::Keys>) -> Result<(), ChannelMonitorUpdateErr>;
879 /// Updates a monitor for the given `funding_txo`.
881 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
882 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
883 /// callbacks with the funding transaction, or any spends of it.
885 /// Further, the implementer must also ensure that each output returned in
886 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
887 /// any spends of any of the outputs.
889 /// Any spends of outputs which should have been registered which aren't passed to
890 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
891 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
893 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
894 /// with success or failure.
896 /// You should probably just call through to
897 /// ChannelMonitor::get_and_clear_pending_monitor_events() for each ChannelMonitor and return
899 fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent>;
902 #[cfg(any(test, feature = "fuzztarget"))]
903 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
904 /// underlying object
905 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
906 fn eq(&self, other: &Self) -> bool {
907 if self.latest_update_id != other.latest_update_id ||
908 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
909 self.destination_script != other.destination_script ||
910 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
911 self.counterparty_payment_script != other.counterparty_payment_script ||
912 self.keys.pubkeys() != other.keys.pubkeys() ||
913 self.funding_info != other.funding_info ||
914 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
915 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
916 self.counterparty_tx_cache != other.counterparty_tx_cache ||
917 self.funding_redeemscript != other.funding_redeemscript ||
918 self.channel_value_satoshis != other.channel_value_satoshis ||
919 self.their_cur_revocation_points != other.their_cur_revocation_points ||
920 self.on_holder_tx_csv != other.on_holder_tx_csv ||
921 self.commitment_secrets != other.commitment_secrets ||
922 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
923 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
924 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
925 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
926 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
927 self.current_holder_commitment_number != other.current_holder_commitment_number ||
928 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
929 self.payment_preimages != other.payment_preimages ||
930 self.pending_monitor_events != other.pending_monitor_events ||
931 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
932 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
933 self.outputs_to_watch != other.outputs_to_watch ||
934 self.lockdown_from_offchain != other.lockdown_from_offchain ||
935 self.holder_tx_signed != other.holder_tx_signed
944 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
945 /// Writes this monitor into the given writer, suitable for writing to disk.
947 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
948 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
949 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
950 /// returned block hash and the the current chain and then reconnecting blocks to get to the
951 /// best chain) upon deserializing the object!
952 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
953 //TODO: We still write out all the serialization here manually instead of using the fancy
954 //serialization framework we have, we should migrate things over to it.
955 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
956 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
958 self.latest_update_id.write(writer)?;
960 // Set in initial Channel-object creation, so should always be set by now:
961 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
963 self.destination_script.write(writer)?;
964 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
965 writer.write_all(&[0; 1])?;
966 broadcasted_holder_revokable_script.0.write(writer)?;
967 broadcasted_holder_revokable_script.1.write(writer)?;
968 broadcasted_holder_revokable_script.2.write(writer)?;
970 writer.write_all(&[1; 1])?;
973 self.counterparty_payment_script.write(writer)?;
974 self.shutdown_script.write(writer)?;
976 self.keys.write(writer)?;
977 writer.write_all(&self.funding_info.0.txid[..])?;
978 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
979 self.funding_info.1.write(writer)?;
980 self.current_counterparty_commitment_txid.write(writer)?;
981 self.prev_counterparty_commitment_txid.write(writer)?;
983 self.counterparty_tx_cache.write(writer)?;
984 self.funding_redeemscript.write(writer)?;
985 self.channel_value_satoshis.write(writer)?;
987 match self.their_cur_revocation_points {
988 Some((idx, pubkey, second_option)) => {
989 writer.write_all(&byte_utils::be48_to_array(idx))?;
990 writer.write_all(&pubkey.serialize())?;
991 match second_option {
992 Some(second_pubkey) => {
993 writer.write_all(&second_pubkey.serialize())?;
996 writer.write_all(&[0; 33])?;
1001 writer.write_all(&byte_utils::be48_to_array(0))?;
1005 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
1007 self.commitment_secrets.write(writer)?;
1009 macro_rules! serialize_htlc_in_commitment {
1010 ($htlc_output: expr) => {
1011 writer.write_all(&[$htlc_output.offered as u8; 1])?;
1012 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
1013 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
1014 writer.write_all(&$htlc_output.payment_hash.0[..])?;
1015 $htlc_output.transaction_output_index.write(writer)?;
1019 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
1020 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
1021 writer.write_all(&txid[..])?;
1022 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
1023 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
1024 serialize_htlc_in_commitment!(htlc_output);
1025 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1029 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
1030 for (ref txid, &(commitment_number, ref txouts)) in self.counterparty_commitment_txn_on_chain.iter() {
1031 writer.write_all(&txid[..])?;
1032 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
1033 (txouts.len() as u64).write(writer)?;
1034 for script in txouts.iter() {
1035 script.write(writer)?;
1039 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
1040 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
1041 writer.write_all(&payment_hash.0[..])?;
1042 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1045 macro_rules! serialize_holder_tx {
1046 ($holder_tx: expr) => {
1047 $holder_tx.txid.write(writer)?;
1048 writer.write_all(&$holder_tx.revocation_key.serialize())?;
1049 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
1050 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
1051 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
1052 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
1054 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
1055 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
1056 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
1057 serialize_htlc_in_commitment!(htlc_output);
1058 if let &Some(ref their_sig) = sig {
1060 writer.write_all(&their_sig.serialize_compact())?;
1064 htlc_source.write(writer)?;
1069 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
1070 writer.write_all(&[1; 1])?;
1071 serialize_holder_tx!(prev_holder_tx);
1073 writer.write_all(&[0; 1])?;
1076 serialize_holder_tx!(self.current_holder_commitment_tx);
1078 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
1079 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
1081 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1082 for payment_preimage in self.payment_preimages.values() {
1083 writer.write_all(&payment_preimage.0[..])?;
1086 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
1087 for event in self.pending_monitor_events.iter() {
1089 MonitorEvent::HTLCEvent(upd) => {
1093 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
1097 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1098 for event in self.pending_events.iter() {
1099 event.write(writer)?;
1102 self.last_block_hash.write(writer)?;
1104 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1105 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1106 writer.write_all(&byte_utils::be32_to_array(**target))?;
1107 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1108 for ev in events.iter() {
1110 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1112 htlc_update.0.write(writer)?;
1113 htlc_update.1.write(writer)?;
1115 OnchainEvent::MaturingOutput { ref descriptor } => {
1117 descriptor.write(writer)?;
1123 (self.outputs_to_watch.len() as u64).write(writer)?;
1124 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1125 txid.write(writer)?;
1126 (output_scripts.len() as u64).write(writer)?;
1127 for script in output_scripts.iter() {
1128 script.write(writer)?;
1131 self.onchain_tx_handler.write(writer)?;
1133 self.lockdown_from_offchain.write(writer)?;
1134 self.holder_tx_signed.write(writer)?;
1140 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1141 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1142 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1143 counterparty_htlc_base_key: &PublicKey, counterparty_delayed_payment_base_key: &PublicKey,
1144 on_holder_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1145 commitment_transaction_number_obscure_factor: u64,
1146 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1148 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1149 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1150 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1151 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1152 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1154 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key: *counterparty_delayed_payment_base_key, counterparty_htlc_base_key: *counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
1156 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_holder_tx_csv);
1158 let holder_tx_sequence = initial_holder_commitment_tx.unsigned_tx.input[0].sequence as u64;
1159 let holder_tx_locktime = initial_holder_commitment_tx.unsigned_tx.lock_time as u64;
1160 let holder_commitment_tx = HolderSignedTx {
1161 txid: initial_holder_commitment_tx.txid(),
1162 revocation_key: initial_holder_commitment_tx.keys.revocation_key,
1163 a_htlc_key: initial_holder_commitment_tx.keys.broadcaster_htlc_key,
1164 b_htlc_key: initial_holder_commitment_tx.keys.countersignatory_htlc_key,
1165 delayed_payment_key: initial_holder_commitment_tx.keys.broadcaster_delayed_payment_key,
1166 per_commitment_point: initial_holder_commitment_tx.keys.per_commitment_point,
1167 feerate_per_kw: initial_holder_commitment_tx.feerate_per_kw,
1168 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1170 // Returning a monitor error before updating tracking points means in case of using
1171 // a concurrent watchtower implementation for same channel, if this one doesn't
1172 // reject update as we do, you MAY have the latest holder valid commitment tx onchain
1173 // for which you want to spend outputs. We're NOT robust again this scenario right
1174 // now but we should consider it later.
1175 onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx).unwrap();
1178 latest_update_id: 0,
1179 commitment_transaction_number_obscure_factor,
1181 destination_script: destination_script.clone(),
1182 broadcasted_holder_revokable_script: None,
1183 counterparty_payment_script,
1188 current_counterparty_commitment_txid: None,
1189 prev_counterparty_commitment_txid: None,
1191 counterparty_tx_cache,
1192 funding_redeemscript,
1193 channel_value_satoshis: channel_value_satoshis,
1194 their_cur_revocation_points: None,
1198 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1199 counterparty_claimable_outpoints: HashMap::new(),
1200 counterparty_commitment_txn_on_chain: HashMap::new(),
1201 counterparty_hash_commitment_number: HashMap::new(),
1203 prev_holder_signed_commitment_tx: None,
1204 current_holder_commitment_tx: holder_commitment_tx,
1205 current_counterparty_commitment_number: 1 << 48,
1206 current_holder_commitment_number: 0xffff_ffff_ffff - ((((holder_tx_sequence & 0xffffff) << 3*8) | (holder_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1208 payment_preimages: HashMap::new(),
1209 pending_monitor_events: Vec::new(),
1210 pending_events: Vec::new(),
1212 onchain_events_waiting_threshold_conf: HashMap::new(),
1213 outputs_to_watch: HashMap::new(),
1217 lockdown_from_offchain: false,
1218 holder_tx_signed: false,
1220 last_block_hash: Default::default(),
1221 secp_ctx: Secp256k1::new(),
1225 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1226 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1227 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1228 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1229 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1230 return Err(MonitorUpdateError("Previous secret did not match new one"));
1233 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1234 // events for now-revoked/fulfilled HTLCs.
1235 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1236 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1241 if !self.payment_preimages.is_empty() {
1242 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1243 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1244 let min_idx = self.get_min_seen_secret();
1245 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1247 self.payment_preimages.retain(|&k, _| {
1248 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1249 if k == htlc.payment_hash {
1253 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1254 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1255 if k == htlc.payment_hash {
1260 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1267 counterparty_hash_commitment_number.remove(&k);
1276 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1277 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1278 /// possibly future revocation/preimage information) to claim outputs where possible.
1279 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1280 pub(super) fn provide_latest_counterparty_commitment_tx_info<L: Deref>(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1281 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1282 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1283 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1285 for &(ref htlc, _) in &htlc_outputs {
1286 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1289 let new_txid = unsigned_commitment_tx.txid();
1290 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1291 log_trace!(logger, "New potential counterparty commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1292 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1293 self.current_counterparty_commitment_txid = Some(new_txid);
1294 self.counterparty_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1295 self.current_counterparty_commitment_number = commitment_number;
1296 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1297 match self.their_cur_revocation_points {
1298 Some(old_points) => {
1299 if old_points.0 == commitment_number + 1 {
1300 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1301 } else if old_points.0 == commitment_number + 2 {
1302 if let Some(old_second_point) = old_points.2 {
1303 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1305 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1308 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1312 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1315 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1316 for htlc in htlc_outputs {
1317 if htlc.0.transaction_output_index.is_some() {
1321 self.counterparty_tx_cache.per_htlc.insert(new_txid, htlcs);
1324 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1325 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1326 /// is important that any clones of this channel monitor (including remote clones) by kept
1327 /// up-to-date as our holder commitment transaction is updated.
1328 /// Panics if set_on_holder_tx_csv has never been called.
1329 pub(super) fn provide_latest_holder_commitment_tx_info(&mut self, commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1330 if self.holder_tx_signed {
1331 return Err(MonitorUpdateError("A holder commitment tx has already been signed, no new holder commitment txn can be sent to our counterparty"));
1333 let txid = commitment_tx.txid();
1334 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1335 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1336 let mut new_holder_commitment_tx = HolderSignedTx {
1338 revocation_key: commitment_tx.keys.revocation_key,
1339 a_htlc_key: commitment_tx.keys.broadcaster_htlc_key,
1340 b_htlc_key: commitment_tx.keys.countersignatory_htlc_key,
1341 delayed_payment_key: commitment_tx.keys.broadcaster_delayed_payment_key,
1342 per_commitment_point: commitment_tx.keys.per_commitment_point,
1343 feerate_per_kw: commitment_tx.feerate_per_kw,
1344 htlc_outputs: htlc_outputs,
1346 // Returning a monitor error before updating tracking points means in case of using
1347 // a concurrent watchtower implementation for same channel, if this one doesn't
1348 // reject update as we do, you MAY have the latest holder valid commitment tx onchain
1349 // for which you want to spend outputs. We're NOT robust again this scenario right
1350 // now but we should consider it later.
1351 if let Err(_) = self.onchain_tx_handler.provide_latest_holder_tx(commitment_tx) {
1352 return Err(MonitorUpdateError("Holder commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1354 self.current_holder_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1355 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1356 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1360 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1361 /// commitment_tx_infos which contain the payment hash have been revoked.
1362 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1363 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1366 pub(super) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1367 where B::Target: BroadcasterInterface,
1370 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1371 broadcaster.broadcast_transaction(tx);
1373 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1376 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1379 /// panics if the given update is not the next update by update_id.
1380 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1381 where B::Target: BroadcasterInterface,
1384 if self.latest_update_id + 1 != updates.update_id {
1385 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1387 for update in updates.updates.drain(..) {
1389 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1390 if self.lockdown_from_offchain { panic!(); }
1391 self.provide_latest_holder_commitment_tx_info(commitment_tx, htlc_outputs)?
1393 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1394 self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1395 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1396 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1397 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1398 self.provide_secret(idx, secret)?,
1399 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1400 self.lockdown_from_offchain = true;
1401 if should_broadcast {
1402 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1404 log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
1409 self.latest_update_id = updates.update_id;
1413 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1415 pub fn get_latest_update_id(&self) -> u64 {
1416 self.latest_update_id
1419 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1420 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1424 /// Gets a list of txids, with their output scripts (in the order they appear in the
1425 /// transaction), which we must learn about spends of via block_connected().
1427 /// (C-not exported) because we have no HashMap bindings
1428 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1429 &self.outputs_to_watch
1432 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1433 /// Generally useful when deserializing as during normal operation the return values of
1434 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1435 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1437 /// (C-not exported) as there is no practical way to track lifetimes of returned values.
1438 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1439 let mut res = Vec::with_capacity(self.counterparty_commitment_txn_on_chain.len() * 2);
1440 for (ref txid, &(_, ref outputs)) in self.counterparty_commitment_txn_on_chain.iter() {
1441 for (idx, output) in outputs.iter().enumerate() {
1442 res.push(((*txid).clone(), idx as u32, output));
1448 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1449 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_monitor_events().
1450 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1451 let mut ret = Vec::new();
1452 mem::swap(&mut ret, &mut self.pending_monitor_events);
1456 /// Gets the list of pending events which were generated by previous actions, clearing the list
1459 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1460 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1461 /// no internal locking in ChannelMonitors.
1462 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1463 let mut ret = Vec::new();
1464 mem::swap(&mut ret, &mut self.pending_events);
1468 /// Can only fail if idx is < get_min_seen_secret
1469 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1470 self.commitment_secrets.get_secret(idx)
1473 pub(super) fn get_min_seen_secret(&self) -> u64 {
1474 self.commitment_secrets.get_min_seen_secret()
1477 pub(super) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1478 self.current_counterparty_commitment_number
1481 pub(super) fn get_cur_holder_commitment_number(&self) -> u64 {
1482 self.current_holder_commitment_number
1485 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1486 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1487 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1488 /// HTLC-Success/HTLC-Timeout transactions.
1489 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1490 /// revoked counterparty commitment tx
1491 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1492 // Most secp and related errors trying to create keys means we have no hope of constructing
1493 // a spend transaction...so we return no transactions to broadcast
1494 let mut claimable_outpoints = Vec::new();
1495 let mut watch_outputs = Vec::new();
1497 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1498 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1500 macro_rules! ignore_error {
1501 ( $thing : expr ) => {
1504 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1509 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);
1510 if commitment_number >= self.get_min_seen_secret() {
1511 let secret = self.get_secret(commitment_number).unwrap();
1512 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1513 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1514 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1515 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_tx_cache.counterparty_delayed_payment_base_key));
1517 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1518 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1520 // First, process non-htlc outputs (to_holder & to_counterparty)
1521 for (idx, outp) in tx.output.iter().enumerate() {
1522 if outp.script_pubkey == revokeable_p2wsh {
1523 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1524 claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
1528 // Then, try to find revoked htlc outputs
1529 if let Some(ref per_commitment_data) = per_commitment_option {
1530 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1531 if let Some(transaction_output_index) = htlc.transaction_output_index {
1532 if transaction_output_index as usize >= tx.output.len() ||
1533 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1534 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1536 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value, htlc: Some(htlc.clone()), on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1537 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1542 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1543 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1544 // We're definitely a counterparty commitment transaction!
1545 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1546 watch_outputs.append(&mut tx.output.clone());
1547 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1549 macro_rules! check_htlc_fails {
1550 ($txid: expr, $commitment_tx: expr) => {
1551 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1552 for &(ref htlc, ref source_option) in outpoints.iter() {
1553 if let &Some(ref source) = source_option {
1554 log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1555 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1556 hash_map::Entry::Occupied(mut entry) => {
1557 let e = entry.get_mut();
1558 e.retain(|ref event| {
1560 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1561 return htlc_update.0 != **source
1566 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1568 hash_map::Entry::Vacant(entry) => {
1569 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1577 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1578 check_htlc_fails!(txid, "current");
1580 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1581 check_htlc_fails!(txid, "counterparty");
1583 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1585 } else if let Some(per_commitment_data) = per_commitment_option {
1586 // While this isn't useful yet, there is a potential race where if a counterparty
1587 // revokes a state at the same time as the commitment transaction for that state is
1588 // confirmed, and the watchtower receives the block before the user, the user could
1589 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1590 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1591 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1593 watch_outputs.append(&mut tx.output.clone());
1594 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1596 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1598 macro_rules! check_htlc_fails {
1599 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1600 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1601 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1602 if let &Some(ref source) = source_option {
1603 // Check if the HTLC is present in the commitment transaction that was
1604 // broadcast, but not if it was below the dust limit, which we should
1605 // fail backwards immediately as there is no way for us to learn the
1606 // payment_preimage.
1607 // Note that if the dust limit were allowed to change between
1608 // commitment transactions we'd want to be check whether *any*
1609 // broadcastable commitment transaction has the HTLC in it, but it
1610 // cannot currently change after channel initialization, so we don't
1612 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1613 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1617 log_trace!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of counterparty commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1618 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1619 hash_map::Entry::Occupied(mut entry) => {
1620 let e = entry.get_mut();
1621 e.retain(|ref event| {
1623 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1624 return htlc_update.0 != **source
1629 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1631 hash_map::Entry::Vacant(entry) => {
1632 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1640 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1641 check_htlc_fails!(txid, "current", 'current_loop);
1643 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1644 check_htlc_fails!(txid, "previous", 'prev_loop);
1647 if let Some(revocation_points) = self.their_cur_revocation_points {
1648 let revocation_point_option =
1649 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1650 else if let Some(point) = revocation_points.2.as_ref() {
1651 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1653 if let Some(revocation_point) = revocation_point_option {
1654 self.counterparty_payment_script = {
1655 // Note that the Network here is ignored as we immediately drop the address for the
1656 // script_pubkey version
1657 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1658 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1661 // Then, try to find htlc outputs
1662 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1663 if let Some(transaction_output_index) = htlc.transaction_output_index {
1664 if transaction_output_index as usize >= tx.output.len() ||
1665 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1666 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1668 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1669 let aggregable = if !htlc.offered { false } else { true };
1670 if preimage.is_some() || !htlc.offered {
1671 let witness_data = InputMaterial::CounterpartyHTLC { per_commitment_point: *revocation_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, preimage, htlc: htlc.clone() };
1672 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1679 (claimable_outpoints, (commitment_txid, watch_outputs))
1682 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1683 fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<TxOut>)>) where L::Target: Logger {
1684 let htlc_txid = tx.txid();
1685 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1686 return (Vec::new(), None)
1689 macro_rules! ignore_error {
1690 ( $thing : expr ) => {
1693 Err(_) => return (Vec::new(), None)
1698 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1699 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1700 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1702 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1703 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv };
1704 let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
1705 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1708 fn broadcast_by_holder_state(&self, commitment_tx: &Transaction, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1709 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1710 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1712 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1713 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1715 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1716 if let Some(transaction_output_index) = htlc.transaction_output_index {
1717 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1718 witness_data: InputMaterial::HolderHTLC {
1719 preimage: if !htlc.offered {
1720 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1721 Some(preimage.clone())
1723 // We can't build an HTLC-Success transaction without the preimage
1727 amount: htlc.amount_msat,
1729 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1733 (claim_requests, watch_outputs, broadcasted_holder_revokable_script)
1736 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1737 /// revoked using data in holder_claimable_outpoints.
1738 /// Should not be used if check_spend_revoked_transaction succeeds.
1739 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1740 let commitment_txid = tx.txid();
1741 let mut claim_requests = Vec::new();
1742 let mut watch_outputs = Vec::new();
1744 macro_rules! wait_threshold_conf {
1745 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1746 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1747 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1748 hash_map::Entry::Occupied(mut entry) => {
1749 let e = entry.get_mut();
1750 e.retain(|ref event| {
1752 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1753 return htlc_update.0 != $source
1758 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1760 hash_map::Entry::Vacant(entry) => {
1761 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1767 macro_rules! append_onchain_update {
1768 ($updates: expr) => {
1769 claim_requests = $updates.0;
1770 watch_outputs.append(&mut $updates.1);
1771 self.broadcasted_holder_revokable_script = $updates.2;
1775 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1776 let mut is_holder_tx = false;
1778 if self.current_holder_commitment_tx.txid == commitment_txid {
1779 is_holder_tx = true;
1780 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1781 let mut res = self.broadcast_by_holder_state(tx, &self.current_holder_commitment_tx);
1782 append_onchain_update!(res);
1783 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1784 if holder_tx.txid == commitment_txid {
1785 is_holder_tx = true;
1786 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1787 let mut res = self.broadcast_by_holder_state(tx, holder_tx);
1788 append_onchain_update!(res);
1792 macro_rules! fail_dust_htlcs_after_threshold_conf {
1793 ($holder_tx: expr) => {
1794 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1795 if htlc.transaction_output_index.is_none() {
1796 if let &Some(ref source) = source {
1797 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1805 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1806 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1807 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1811 (claim_requests, (commitment_txid, watch_outputs))
1814 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1815 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1816 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1817 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1818 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1819 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1820 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1821 /// out-of-band the other node operator to coordinate with him if option is available to you.
1822 /// In any-case, choice is up to the user.
1823 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1824 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1825 self.holder_tx_signed = true;
1826 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1827 let txid = commitment_tx.txid();
1828 let mut res = vec![commitment_tx];
1829 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1830 if let Some(vout) = htlc.0.transaction_output_index {
1831 let preimage = if !htlc.0.offered {
1832 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1833 // We can't build an HTLC-Success transaction without the preimage
1837 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1838 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1843 // 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.
1844 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1850 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1851 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1852 /// revoked commitment transaction.
1853 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1854 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1855 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1856 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
1857 let txid = commitment_tx.txid();
1858 let mut res = vec![commitment_tx];
1859 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1860 if let Some(vout) = htlc.0.transaction_output_index {
1861 let preimage = if !htlc.0.offered {
1862 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1863 // We can't build an HTLC-Success transaction without the preimage
1867 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1868 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1878 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1879 /// ChainListener::block_connected.
1880 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1881 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1883 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>)>
1884 where B::Target: BroadcasterInterface,
1885 F::Target: FeeEstimator,
1888 for tx in txn_matched {
1889 let mut output_val = 0;
1890 for out in tx.output.iter() {
1891 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1892 output_val += out.value;
1893 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1897 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1898 let mut watch_outputs = Vec::new();
1899 let mut claimable_outpoints = Vec::new();
1900 for tx in txn_matched {
1901 if tx.input.len() == 1 {
1902 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1903 // commitment transactions and HTLC transactions will all only ever have one input,
1904 // which is an easy way to filter out any potential non-matching txn for lazy
1906 let prevout = &tx.input[0].previous_output;
1907 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1908 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1909 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1910 if !new_outputs.1.is_empty() {
1911 watch_outputs.push(new_outputs);
1913 if new_outpoints.is_empty() {
1914 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1915 if !new_outputs.1.is_empty() {
1916 watch_outputs.push(new_outputs);
1918 claimable_outpoints.append(&mut new_outpoints);
1920 claimable_outpoints.append(&mut new_outpoints);
1923 if let Some(&(commitment_number, _)) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1924 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1925 claimable_outpoints.append(&mut new_outpoints);
1926 if let Some(new_outputs) = new_outputs_option {
1927 watch_outputs.push(new_outputs);
1932 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1933 // can also be resolved in a few other ways which can have more than one output. Thus,
1934 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1935 self.is_resolving_htlc_output(&tx, height, &logger);
1937 self.is_paying_spendable_output(&tx, height, &logger);
1939 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1940 if should_broadcast {
1941 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() }});
1943 if should_broadcast {
1944 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1945 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1946 self.holder_tx_signed = true;
1947 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_holder_state(&commitment_tx, &self.current_holder_commitment_tx);
1948 if !new_outputs.is_empty() {
1949 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
1951 claimable_outpoints.append(&mut new_outpoints);
1954 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1957 OnchainEvent::HTLCUpdate { htlc_update } => {
1958 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1959 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1960 payment_hash: htlc_update.1,
1961 payment_preimage: None,
1962 source: htlc_update.0,
1965 OnchainEvent::MaturingOutput { descriptor } => {
1966 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1967 self.pending_events.push(Event::SpendableOutputs {
1968 outputs: vec![descriptor]
1975 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1977 self.last_block_hash = block_hash.clone();
1978 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1979 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1985 fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)
1986 where B::Target: BroadcasterInterface,
1987 F::Target: FeeEstimator,
1990 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1991 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1993 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1994 //- maturing spendable output has transaction paying us has been disconnected
1997 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1999 self.last_block_hash = block_hash.clone();
2002 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2003 // We need to consider all HTLCs which are:
2004 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2005 // transactions and we'd end up in a race, or
2006 // * are in our latest holder commitment transaction, as this is the thing we will
2007 // broadcast if we go on-chain.
2008 // Note that we consider HTLCs which were below dust threshold here - while they don't
2009 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2010 // to the source, and if we don't fail the channel we will have to ensure that the next
2011 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2012 // easier to just fail the channel as this case should be rare enough anyway.
2013 macro_rules! scan_commitment {
2014 ($htlcs: expr, $holder_tx: expr) => {
2015 for ref htlc in $htlcs {
2016 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2017 // chain with enough room to claim the HTLC without our counterparty being able to
2018 // time out the HTLC first.
2019 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2020 // concern is being able to claim the corresponding inbound HTLC (on another
2021 // channel) before it expires. In fact, we don't even really care if our
2022 // counterparty here claims such an outbound HTLC after it expired as long as we
2023 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2024 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2025 // we give ourselves a few blocks of headroom after expiration before going
2026 // on-chain for an expired HTLC.
2027 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2028 // from us until we've reached the point where we go on-chain with the
2029 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2030 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2031 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2032 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2033 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2034 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2035 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2036 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2037 // The final, above, condition is checked for statically in channelmanager
2038 // with CHECK_CLTV_EXPIRY_SANITY_2.
2039 let htlc_outbound = $holder_tx == htlc.offered;
2040 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2041 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2042 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2049 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2051 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2052 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2053 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2056 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2057 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2058 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2065 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2066 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2067 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2068 'outer_loop: for input in &tx.input {
2069 let mut payment_data = None;
2070 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2071 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2072 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2073 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2075 macro_rules! log_claim {
2076 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2077 // We found the output in question, but aren't failing it backwards
2078 // as we have no corresponding source and no valid counterparty commitment txid
2079 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2080 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2081 let outbound_htlc = $holder_tx == $htlc.offered;
2082 if ($holder_tx && revocation_sig_claim) ||
2083 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2084 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2085 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2086 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2087 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2089 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2090 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2091 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2092 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2097 macro_rules! check_htlc_valid_counterparty {
2098 ($counterparty_txid: expr, $htlc_output: expr) => {
2099 if let Some(txid) = $counterparty_txid {
2100 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2101 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2102 if let &Some(ref source) = pending_source {
2103 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2104 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2113 macro_rules! scan_commitment {
2114 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2115 for (ref htlc_output, source_option) in $htlcs {
2116 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2117 if let Some(ref source) = source_option {
2118 log_claim!($tx_info, $holder_tx, htlc_output, true);
2119 // We have a resolution of an HTLC either from one of our latest
2120 // holder commitment transactions or an unrevoked counterparty commitment
2121 // transaction. This implies we either learned a preimage, the HTLC
2122 // has timed out, or we screwed up. In any case, we should now
2123 // resolve the source HTLC with the original sender.
2124 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2125 } else if !$holder_tx {
2126 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2127 if payment_data.is_none() {
2128 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2131 if payment_data.is_none() {
2132 log_claim!($tx_info, $holder_tx, htlc_output, false);
2133 continue 'outer_loop;
2140 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2141 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2142 "our latest holder commitment tx", true);
2144 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2145 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2146 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2147 "our previous holder commitment tx", true);
2150 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2151 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2152 "counterparty commitment tx", false);
2155 // Check that scan_commitment, above, decided there is some source worth relaying an
2156 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2157 if let Some((source, payment_hash)) = payment_data {
2158 let mut payment_preimage = PaymentPreimage([0; 32]);
2159 if accepted_preimage_claim {
2160 if !self.pending_monitor_events.iter().any(
2161 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2162 payment_preimage.0.copy_from_slice(&input.witness[3]);
2163 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2165 payment_preimage: Some(payment_preimage),
2169 } else if offered_preimage_claim {
2170 if !self.pending_monitor_events.iter().any(
2171 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2172 upd.source == source
2174 payment_preimage.0.copy_from_slice(&input.witness[1]);
2175 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2177 payment_preimage: Some(payment_preimage),
2182 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);
2183 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2184 hash_map::Entry::Occupied(mut entry) => {
2185 let e = entry.get_mut();
2186 e.retain(|ref event| {
2188 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2189 return htlc_update.0 != source
2194 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2196 hash_map::Entry::Vacant(entry) => {
2197 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2205 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2206 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2207 let mut spendable_output = None;
2208 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2209 if i > ::std::u16::MAX as usize {
2210 // While it is possible that an output exists on chain which is greater than the
2211 // 2^16th output in a given transaction, this is only possible if the output is not
2212 // in a lightning transaction and was instead placed there by some third party who
2213 // wishes to give us money for no reason.
2214 // Namely, any lightning transactions which we pre-sign will never have anywhere
2215 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2216 // scripts are not longer than one byte in length and because they are inherently
2217 // non-standard due to their size.
2218 // Thus, it is completely safe to ignore such outputs, and while it may result in
2219 // us ignoring non-lightning fund to us, that is only possible if someone fills
2220 // nearly a full block with garbage just to hit this case.
2223 if outp.script_pubkey == self.destination_script {
2224 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2225 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2226 output: outp.clone(),
2229 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2230 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2231 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2232 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2233 per_commitment_point: broadcasted_holder_revokable_script.1,
2234 to_self_delay: self.on_holder_tx_csv,
2235 output: outp.clone(),
2236 key_derivation_params: self.keys.key_derivation_params(),
2237 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2241 } else if self.counterparty_payment_script == outp.script_pubkey {
2242 spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
2243 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
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: OutPoint { txid: tx.txid(), index: i as u16 },
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_holder_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 counterparty_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_counterparty_commitment_txid = Readable::read(reader)?;
2315 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2317 let counterparty_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_holder_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 counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2357 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2358 for _ in 0..counterparty_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(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2366 return Err(DecodeError::InvalidValue);
2370 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2371 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2372 for _ in 0..counterparty_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(_) = counterparty_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2381 return Err(DecodeError::InvalidValue);
2385 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2386 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2387 for _ in 0..counterparty_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(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2391 return Err(DecodeError::InvalidValue);
2395 macro_rules! read_holder_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_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2430 Some(read_holder_tx!())
2432 _ => return Err(DecodeError::InvalidValue),
2434 let current_holder_commitment_tx = read_holder_tx!();
2436 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2437 let current_holder_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::<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 holder_tx_signed = Readable::read(reader)?;
2516 Ok((last_block_hash.clone(), ChannelMonitor {
2518 commitment_transaction_number_obscure_factor,
2521 broadcasted_holder_revokable_script,
2522 counterparty_payment_script,
2527 current_counterparty_commitment_txid,
2528 prev_counterparty_commitment_txid,
2530 counterparty_tx_cache,
2531 funding_redeemscript,
2532 channel_value_satoshis,
2533 their_cur_revocation_points,
2538 counterparty_claimable_outpoints,
2539 counterparty_commitment_txn_on_chain,
2540 counterparty_hash_commitment_number,
2542 prev_holder_signed_commitment_tx,
2543 current_holder_commitment_tx,
2544 current_counterparty_commitment_number,
2545 current_holder_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, HolderCommitmentTransaction};
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 $preimages_slice.iter().enumerate() {
2611 res.push((HTLCOutputInCommitment {
2615 payment_hash: preimage.1.clone(),
2616 transaction_output_index: Some(idx as u32),
2623 macro_rules! preimages_to_holder_htlcs {
2624 ($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 holder 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, HolderCommitmentTransaction::dummy());
2662 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2663 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2664 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2665 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2666 monitor.provide_latest_counterparty_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 holder commitment tx info, pruning only element 18 as we still care about the
2687 // previous commitment tx's preimages too
2688 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_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_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_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, $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 as u32),
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.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2724 let sig = secp_ctx.sign(&sighash, &privkey);
2725 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2726 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2727 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2728 if *$input_type == InputDescriptors::RevokedOutput {
2729 $sighash_parts.access_witness($idx).push(vec!(1));
2730 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2731 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2732 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2733 $sighash_parts.access_witness($idx).push(vec![0]);
2735 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2737 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2738 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2739 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2740 println!("witness[2] {}", $sighash_parts.access_witness($idx)[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_holder, 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 inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2767 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2768 for (idx, inp) in inputs_des.iter().enumerate() {
2769 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2772 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));
2774 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2775 claim_tx.input.clear();
2776 sum_actual_sigs = 0;
2778 claim_tx.input.push(TxIn {
2779 previous_output: BitcoinOutPoint {
2783 script_sig: Script::new(),
2784 sequence: 0xfffffffd,
2785 witness: Vec::new(),
2788 let base_weight = claim_tx.get_weight();
2789 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2791 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2792 for (idx, inp) in inputs_des.iter().enumerate() {
2793 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2796 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));
2798 // Justice tx with 1 revoked HTLC-Success tx output
2799 claim_tx.input.clear();
2800 sum_actual_sigs = 0;
2801 claim_tx.input.push(TxIn {
2802 previous_output: BitcoinOutPoint {
2806 script_sig: Script::new(),
2807 sequence: 0xfffffffd,
2808 witness: Vec::new(),
2810 let base_weight = claim_tx.get_weight();
2811 let inputs_des = vec![InputDescriptors::RevokedOutput];
2813 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2814 for (idx, inp) in inputs_des.iter().enumerate() {
2815 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2818 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));
2821 // Further testing is done in the ChannelManager integration tests.