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 [`chain::Watch`] 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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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 //! [`chain::Watch`]: ../../chain/trait.Watch.html
25 use bitcoin::blockdata::block::BlockHeader;
26 use bitcoin::blockdata::transaction::{TxOut,Transaction};
27 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
28 use bitcoin::blockdata::script::{Script, Builder};
29 use bitcoin::blockdata::opcodes;
30 use bitcoin::consensus::encode;
32 use bitcoin::hashes::Hash;
33 use bitcoin::hashes::sha256::Hash as Sha256;
34 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
36 use bitcoin::secp256k1::{Secp256k1,Signature};
37 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
38 use bitcoin::secp256k1;
40 use ln::msgs::DecodeError;
42 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HolderCommitmentTransaction, HTLCType};
43 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
44 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
47 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
48 use chain::transaction::OutPoint;
49 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
50 use util::logger::Logger;
51 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
52 use util::{byte_utils, events};
53 use util::events::Event;
55 use std::collections::{HashMap, HashSet, hash_map};
61 /// An update generated by the underlying Channel itself which contains some new information the
62 /// ChannelMonitor should be made aware of.
63 #[cfg_attr(test, derive(PartialEq))]
66 pub struct ChannelMonitorUpdate {
67 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
68 /// The sequence number of this update. Updates *must* be replayed in-order according to this
69 /// sequence number (and updates may panic if they are not). The update_id values are strictly
70 /// increasing and increase by one for each new update.
72 /// This sequence number is also used to track up to which points updates which returned
73 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
74 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
78 impl Writeable for ChannelMonitorUpdate {
79 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
80 self.update_id.write(w)?;
81 (self.updates.len() as u64).write(w)?;
82 for update_step in self.updates.iter() {
83 update_step.write(w)?;
88 impl Readable for ChannelMonitorUpdate {
89 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
90 let update_id: u64 = Readable::read(r)?;
91 let len: u64 = Readable::read(r)?;
92 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
94 updates.push(Readable::read(r)?);
96 Ok(Self { update_id, updates })
100 /// An error enum representing a failure to persist a channel monitor update.
102 pub enum ChannelMonitorUpdateErr {
103 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
104 /// our state failed, but is expected to succeed at some point in the future).
106 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
107 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
108 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
109 /// restore the channel to an operational state.
111 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
112 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
113 /// writing out the latest ChannelManager state.
115 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
116 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
117 /// to claim it on this channel) and those updates must be applied wherever they can be. At
118 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
119 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
120 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
123 /// Note that even if updates made after TemporaryFailure succeed you must still call
124 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
127 /// Note that the update being processed here will not be replayed for you when you call
128 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
129 /// with the persisted ChannelMonitor on your own local disk prior to returning a
130 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
131 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
134 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
135 /// remote location (with local copies persisted immediately), it is anticipated that all
136 /// updates will return TemporaryFailure until the remote copies could be updated.
138 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
139 /// different watchtower and cannot update with all watchtowers that were previously informed
140 /// of this channel).
142 /// At reception of this error, ChannelManager will force-close the channel and return at
143 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
144 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
145 /// update must be rejected.
147 /// This failure may also signal a failure to update the local persisted copy of one of
148 /// the channel monitor instance.
150 /// Note that even when you fail a holder commitment transaction update, you must store the
151 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
152 /// broadcasts it (e.g distributed channel-monitor deployment)
154 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
155 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
156 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
157 /// lagging behind on block processing.
161 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
162 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
163 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
165 /// Contains a human-readable error message.
167 pub struct MonitorUpdateError(pub &'static str);
169 /// An event to be processed by the ChannelManager.
171 pub enum MonitorEvent {
172 /// A monitor event containing an HTLCUpdate.
173 HTLCEvent(HTLCUpdate),
175 /// A monitor event that the Channel's commitment transaction was broadcasted.
176 CommitmentTxBroadcasted(OutPoint),
179 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
180 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
181 /// preimage claim backward will lead to loss of funds.
183 /// [`chain::Watch`]: ../../chain/trait.Watch.html
184 #[derive(Clone, PartialEq)]
185 pub struct HTLCUpdate {
186 pub(super) payment_hash: PaymentHash,
187 pub(super) payment_preimage: Option<PaymentPreimage>,
188 pub(super) source: HTLCSource
190 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
192 /// An implementation of [`chain::Watch`] for monitoring channels.
194 /// Connected and disconnected blocks must be provided to `ChainMonitor` as documented by
195 /// [`chain::Watch`]. May be used in conjunction with [`ChannelManager`] to monitor channels locally
196 /// or used independently to monitor channels remotely.
198 /// [`chain::Watch`]: ../../chain/trait.Watch.html
199 /// [`ChannelManager`]: ../channelmanager/struct.ChannelManager.html
200 pub struct ChainMonitor<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref>
201 where C::Target: chain::Filter,
202 T::Target: BroadcasterInterface,
203 F::Target: FeeEstimator,
207 pub monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
208 chain_source: Option<C>,
214 impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, C, T, F, L>
215 where C::Target: chain::Filter,
216 T::Target: BroadcasterInterface,
217 F::Target: FeeEstimator,
220 /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
221 /// of a channel and reacting accordingly based on transactions in the connected block. See
222 /// [`ChannelMonitor::block_connected`] for details. Any HTLCs that were resolved on chain will
223 /// be returned by [`chain::Watch::release_pending_monitor_events`].
225 /// Calls back to [`chain::Filter`] if any monitor indicated new outputs to watch, returning
226 /// `true` if so. Subsequent calls must not exclude any transactions matching the new outputs
227 /// nor any in-block descendants of such transactions. It is not necessary to re-fetch the block
228 /// to obtain updated `txdata`.
230 /// [`ChannelMonitor::block_connected`]: struct.ChannelMonitor.html#method.block_connected
231 /// [`chain::Watch::release_pending_monitor_events`]: ../../chain/trait.Watch.html#tymethod.release_pending_monitor_events
232 /// [`chain::Filter`]: ../../chain/trait.Filter.html
233 pub fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) -> bool {
234 let mut has_new_outputs_to_watch = false;
236 let mut monitors = self.monitors.lock().unwrap();
237 for monitor in monitors.values_mut() {
238 let mut txn_outputs = monitor.block_connected(header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
239 has_new_outputs_to_watch |= !txn_outputs.is_empty();
241 if let Some(ref chain_source) = self.chain_source {
242 for (txid, outputs) in txn_outputs.drain(..) {
243 for (idx, output) in outputs.iter().enumerate() {
244 chain_source.register_output(&OutPoint { txid, index: idx as u16 }, &output.script_pubkey);
250 has_new_outputs_to_watch
253 /// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
254 /// of a channel based on the disconnected block. See [`ChannelMonitor::block_disconnected`] for
257 /// [`ChannelMonitor::block_disconnected`]: struct.ChannelMonitor.html#method.block_disconnected
258 pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
259 let mut monitors = self.monitors.lock().unwrap();
260 for monitor in monitors.values_mut() {
261 monitor.block_disconnected(header, disconnected_height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
266 impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, C, T, F, L>
267 where C::Target: chain::Filter,
268 T::Target: BroadcasterInterface,
269 F::Target: FeeEstimator,
272 /// Creates a new `ChainMonitor` used to watch on-chain activity pertaining to channels.
274 /// When an optional chain source implementing [`chain::Filter`] is provided, the chain monitor
275 /// will call back to it indicating transactions and outputs of interest. This allows clients to
276 /// pre-filter blocks or only fetch blocks matching a compact filter. Otherwise, clients may
277 /// always need to fetch full blocks absent another means for determining which blocks contain
278 /// transactions relevant to the watched channels.
280 /// [`chain::Filter`]: ../../chain/trait.Filter.html
281 pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F) -> Self {
283 monitors: Mutex::new(HashMap::new()),
287 fee_estimator: feeest,
291 /// Adds the monitor that watches the channel referred to by the given outpoint.
293 /// Calls back to [`chain::Filter`] with the funding transaction and outputs to watch.
295 /// [`chain::Filter`]: ../../chain/trait.Filter.html
296 fn add_monitor(&self, outpoint: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
297 let mut monitors = self.monitors.lock().unwrap();
298 let entry = match monitors.entry(outpoint) {
299 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given outpoint is already present")),
300 hash_map::Entry::Vacant(e) => e,
303 let funding_txo = monitor.get_funding_txo();
304 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
306 if let Some(ref chain_source) = self.chain_source {
307 chain_source.register_tx(&funding_txo.0.txid, &funding_txo.1);
308 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
309 for (idx, script_pubkey) in outputs.iter().enumerate() {
310 chain_source.register_output(&OutPoint { txid: *txid, index: idx as u16 }, &script_pubkey);
315 entry.insert(monitor);
319 /// Updates the monitor that watches the channel referred to by the given outpoint.
320 fn update_monitor(&self, outpoint: OutPoint, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
321 let mut monitors = self.monitors.lock().unwrap();
322 match monitors.get_mut(&outpoint) {
323 Some(orig_monitor) => {
324 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
325 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
327 None => Err(MonitorUpdateError("No such monitor registered"))
332 impl<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, C, T, F, L>
333 where C::Target: chain::Filter,
334 T::Target: BroadcasterInterface,
335 F::Target: FeeEstimator,
338 type Keys = ChanSigner;
340 fn watch_channel(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
341 match self.add_monitor(funding_txo, monitor) {
343 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
347 fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
348 match self.update_monitor(funding_txo, update) {
350 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
354 fn release_pending_monitor_events(&self) -> Vec<MonitorEvent> {
355 let mut pending_monitor_events = Vec::new();
356 for chan in self.monitors.lock().unwrap().values_mut() {
357 pending_monitor_events.append(&mut chan.get_and_clear_pending_monitor_events());
359 pending_monitor_events
363 impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> events::EventsProvider for ChainMonitor<ChanSigner, C, T, F, L>
364 where C::Target: chain::Filter,
365 T::Target: BroadcasterInterface,
366 F::Target: FeeEstimator,
369 fn get_and_clear_pending_events(&self) -> Vec<Event> {
370 let mut pending_events = Vec::new();
371 for chan in self.monitors.lock().unwrap().values_mut() {
372 pending_events.append(&mut chan.get_and_clear_pending_events());
378 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
379 /// instead claiming it in its own individual transaction.
380 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
381 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
382 /// HTLC-Success transaction.
383 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
384 /// transaction confirmed (and we use it in a few more, equivalent, places).
385 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
386 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
387 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
388 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
389 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
390 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
391 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
392 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
393 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
394 /// accurate block height.
395 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
396 /// with at worst this delay, so we are not only using this value as a mercy for them but also
397 /// us as a safeguard to delay with enough time.
398 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
399 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
400 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
401 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
402 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
403 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
404 /// keeping bumping another claim tx to solve the outpoint.
405 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
406 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
407 /// refuse to accept a new HTLC.
409 /// This is used for a few separate purposes:
410 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
411 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
413 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
414 /// condition with the above), we will fail this HTLC without telling the user we received it,
415 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
416 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
418 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
419 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
421 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
422 /// in a race condition between the user connecting a block (which would fail it) and the user
423 /// providing us the preimage (which would claim it).
425 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
426 /// end up force-closing the channel on us to claim it.
427 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
429 #[derive(Clone, PartialEq)]
430 struct HolderSignedTx {
431 /// txid of the transaction in tx, just used to make comparison faster
433 revocation_key: PublicKey,
434 a_htlc_key: PublicKey,
435 b_htlc_key: PublicKey,
436 delayed_payment_key: PublicKey,
437 per_commitment_point: PublicKey,
439 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
442 /// We use this to track counterparty commitment transactions and htlcs outputs and
443 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
445 struct CounterpartyCommitmentTransaction {
446 counterparty_delayed_payment_base_key: PublicKey,
447 counterparty_htlc_base_key: PublicKey,
448 on_counterparty_tx_csv: u16,
449 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
452 impl Writeable for CounterpartyCommitmentTransaction {
453 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
454 self.counterparty_delayed_payment_base_key.write(w)?;
455 self.counterparty_htlc_base_key.write(w)?;
456 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
457 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
458 for (ref txid, ref htlcs) in self.per_htlc.iter() {
459 w.write_all(&txid[..])?;
460 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
461 for &ref htlc in htlcs.iter() {
468 impl Readable for CounterpartyCommitmentTransaction {
469 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
470 let counterparty_commitment_transaction = {
471 let counterparty_delayed_payment_base_key = Readable::read(r)?;
472 let counterparty_htlc_base_key = Readable::read(r)?;
473 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
474 let per_htlc_len: u64 = Readable::read(r)?;
475 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
476 for _ in 0..per_htlc_len {
477 let txid: Txid = Readable::read(r)?;
478 let htlcs_count: u64 = Readable::read(r)?;
479 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
480 for _ in 0..htlcs_count {
481 let htlc = Readable::read(r)?;
484 if let Some(_) = per_htlc.insert(txid, htlcs) {
485 return Err(DecodeError::InvalidValue);
488 CounterpartyCommitmentTransaction {
489 counterparty_delayed_payment_base_key,
490 counterparty_htlc_base_key,
491 on_counterparty_tx_csv,
495 Ok(counterparty_commitment_transaction)
499 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
500 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
501 /// a new bumped one in case of lenghty confirmation delay
502 #[derive(Clone, PartialEq)]
503 pub(crate) enum InputMaterial {
505 per_commitment_point: PublicKey,
506 counterparty_delayed_payment_base_key: PublicKey,
507 counterparty_htlc_base_key: PublicKey,
508 per_commitment_key: SecretKey,
509 input_descriptor: InputDescriptors,
511 htlc: Option<HTLCOutputInCommitment>,
512 on_counterparty_tx_csv: u16,
515 per_commitment_point: PublicKey,
516 counterparty_delayed_payment_base_key: PublicKey,
517 counterparty_htlc_base_key: PublicKey,
518 preimage: Option<PaymentPreimage>,
519 htlc: HTLCOutputInCommitment
522 preimage: Option<PaymentPreimage>,
526 funding_redeemscript: Script,
530 impl Writeable for InputMaterial {
531 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
533 &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} => {
534 writer.write_all(&[0; 1])?;
535 per_commitment_point.write(writer)?;
536 counterparty_delayed_payment_base_key.write(writer)?;
537 counterparty_htlc_base_key.write(writer)?;
538 writer.write_all(&per_commitment_key[..])?;
539 input_descriptor.write(writer)?;
540 writer.write_all(&byte_utils::be64_to_array(*amount))?;
542 on_counterparty_tx_csv.write(writer)?;
544 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
545 writer.write_all(&[1; 1])?;
546 per_commitment_point.write(writer)?;
547 counterparty_delayed_payment_base_key.write(writer)?;
548 counterparty_htlc_base_key.write(writer)?;
549 preimage.write(writer)?;
552 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
553 writer.write_all(&[2; 1])?;
554 preimage.write(writer)?;
555 writer.write_all(&byte_utils::be64_to_array(*amount))?;
557 &InputMaterial::Funding { ref funding_redeemscript } => {
558 writer.write_all(&[3; 1])?;
559 funding_redeemscript.write(writer)?;
566 impl Readable for InputMaterial {
567 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
568 let input_material = match <u8 as Readable>::read(reader)? {
570 let per_commitment_point = Readable::read(reader)?;
571 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
572 let counterparty_htlc_base_key = Readable::read(reader)?;
573 let per_commitment_key = Readable::read(reader)?;
574 let input_descriptor = Readable::read(reader)?;
575 let amount = Readable::read(reader)?;
576 let htlc = Readable::read(reader)?;
577 let on_counterparty_tx_csv = Readable::read(reader)?;
578 InputMaterial::Revoked {
579 per_commitment_point,
580 counterparty_delayed_payment_base_key,
581 counterparty_htlc_base_key,
586 on_counterparty_tx_csv
590 let per_commitment_point = Readable::read(reader)?;
591 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
592 let counterparty_htlc_base_key = Readable::read(reader)?;
593 let preimage = Readable::read(reader)?;
594 let htlc = Readable::read(reader)?;
595 InputMaterial::CounterpartyHTLC {
596 per_commitment_point,
597 counterparty_delayed_payment_base_key,
598 counterparty_htlc_base_key,
604 let preimage = Readable::read(reader)?;
605 let amount = Readable::read(reader)?;
606 InputMaterial::HolderHTLC {
612 InputMaterial::Funding {
613 funding_redeemscript: Readable::read(reader)?,
616 _ => return Err(DecodeError::InvalidValue),
622 /// ClaimRequest is a descriptor structure to communicate between detection
623 /// and reaction module. They are generated by ChannelMonitor while parsing
624 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
625 /// is responsible for opportunistic aggregation, selecting and enforcing
626 /// bumping logic, building and signing transactions.
627 pub(crate) struct ClaimRequest {
628 // Block height before which claiming is exclusive to one party,
629 // after reaching it, claiming may be contentious.
630 pub(crate) absolute_timelock: u32,
631 // Timeout tx must have nLocktime set which means aggregating multiple
632 // ones must take the higher nLocktime among them to satisfy all of them.
633 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
634 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
635 // Do simplify we mark them as non-aggregable.
636 pub(crate) aggregable: bool,
637 // Basic bitcoin outpoint (txid, vout)
638 pub(crate) outpoint: BitcoinOutPoint,
639 // Following outpoint type, set of data needed to generate transaction digest
640 // and satisfy witness program.
641 pub(crate) witness_data: InputMaterial
644 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
645 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
646 #[derive(Clone, PartialEq)]
648 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
649 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
650 /// only win from it, so it's never an OnchainEvent
652 htlc_update: (HTLCSource, PaymentHash),
655 descriptor: SpendableOutputDescriptor,
659 const SERIALIZATION_VERSION: u8 = 1;
660 const MIN_SERIALIZATION_VERSION: u8 = 1;
662 #[cfg_attr(test, derive(PartialEq))]
664 pub(super) enum ChannelMonitorUpdateStep {
665 LatestHolderCommitmentTXInfo {
666 commitment_tx: HolderCommitmentTransaction,
667 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
669 LatestCounterpartyCommitmentTXInfo {
670 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
671 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
672 commitment_number: u64,
673 their_revocation_point: PublicKey,
676 payment_preimage: PaymentPreimage,
682 /// Used to indicate that the no future updates will occur, and likely that the latest holder
683 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
685 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
686 /// think we've fallen behind!
687 should_broadcast: bool,
691 impl Writeable for ChannelMonitorUpdateStep {
692 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
694 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
696 commitment_tx.write(w)?;
697 (htlc_outputs.len() as u64).write(w)?;
698 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
704 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
706 unsigned_commitment_tx.write(w)?;
707 commitment_number.write(w)?;
708 their_revocation_point.write(w)?;
709 (htlc_outputs.len() as u64).write(w)?;
710 for &(ref output, ref source) in htlc_outputs.iter() {
712 source.as_ref().map(|b| b.as_ref()).write(w)?;
715 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
717 payment_preimage.write(w)?;
719 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
724 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
726 should_broadcast.write(w)?;
732 impl Readable for ChannelMonitorUpdateStep {
733 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
734 match Readable::read(r)? {
736 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
737 commitment_tx: Readable::read(r)?,
739 let len: u64 = Readable::read(r)?;
740 let mut res = Vec::new();
742 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
749 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
750 unsigned_commitment_tx: Readable::read(r)?,
751 commitment_number: Readable::read(r)?,
752 their_revocation_point: Readable::read(r)?,
754 let len: u64 = Readable::read(r)?;
755 let mut res = Vec::new();
757 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
764 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
765 payment_preimage: Readable::read(r)?,
769 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
770 idx: Readable::read(r)?,
771 secret: Readable::read(r)?,
775 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
776 should_broadcast: Readable::read(r)?
779 _ => Err(DecodeError::InvalidValue),
784 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
785 /// on-chain transactions to ensure no loss of funds occurs.
787 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
788 /// information and are actively monitoring the chain.
790 /// Pending Events or updated HTLCs which have not yet been read out by
791 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
792 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
793 /// gotten are fully handled before re-serializing the new state.
794 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
795 latest_update_id: u64,
796 commitment_transaction_number_obscure_factor: u64,
798 destination_script: Script,
799 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
800 counterparty_payment_script: Script,
801 shutdown_script: Script,
804 funding_info: (OutPoint, Script),
805 current_counterparty_commitment_txid: Option<Txid>,
806 prev_counterparty_commitment_txid: Option<Txid>,
808 counterparty_tx_cache: CounterpartyCommitmentTransaction,
809 funding_redeemscript: Script,
810 channel_value_satoshis: u64,
811 // first is the idx of the first of the two revocation points
812 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
814 on_holder_tx_csv: u16,
816 commitment_secrets: CounterpartyCommitmentSecrets,
817 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
818 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
819 /// Nor can we figure out their commitment numbers without the commitment transaction they are
820 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
821 /// commitment transactions which we find on-chain, mapping them to the commitment number which
822 /// can be used to derive the revocation key and claim the transactions.
823 counterparty_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
824 /// Cache used to make pruning of payment_preimages faster.
825 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
826 /// counterparty transactions (ie should remain pretty small).
827 /// Serialized to disk but should generally not be sent to Watchtowers.
828 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
830 // We store two holder commitment transactions to avoid any race conditions where we may update
831 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
832 // various monitors for one channel being out of sync, and us broadcasting a holder
833 // transaction for which we have deleted claim information on some watchtowers.
834 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
835 current_holder_commitment_tx: HolderSignedTx,
837 // Used just for ChannelManager to make sure it has the latest channel data during
839 current_counterparty_commitment_number: u64,
840 // Used just for ChannelManager to make sure it has the latest channel data during
842 current_holder_commitment_number: u64,
844 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
846 pending_monitor_events: Vec<MonitorEvent>,
847 pending_events: Vec<Event>,
849 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
850 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
851 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
852 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
854 // If we get serialized out and re-read, we need to make sure that the chain monitoring
855 // interface knows about the TXOs that we want to be notified of spends of. We could probably
856 // be smart and derive them from the above storage fields, but its much simpler and more
857 // Obviously Correct (tm) if we just keep track of them explicitly.
858 outputs_to_watch: HashMap<Txid, Vec<Script>>,
861 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
863 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
865 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
866 // channel has been force-closed. After this is set, no further holder commitment transaction
867 // updates may occur, and we panic!() if one is provided.
868 lockdown_from_offchain: bool,
870 // Set once we've signed a holder commitment transaction and handed it over to our
871 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
872 // may occur, and we fail any such monitor updates.
874 // In case of update rejection due to a locally already signed commitment transaction, we
875 // nevertheless store update content to track in case of concurrent broadcast by another
876 // remote monitor out-of-order with regards to the block view.
877 holder_tx_signed: bool,
879 // We simply modify last_block_hash in Channel's block_connected so that serialization is
880 // consistent but hopefully the users' copy handles block_connected in a consistent way.
881 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
882 // their last_block_hash from its state and not based on updated copies that didn't run through
883 // the full block_connected).
884 last_block_hash: BlockHash,
885 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
888 #[cfg(any(test, feature = "fuzztarget"))]
889 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
890 /// underlying object
891 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
892 fn eq(&self, other: &Self) -> bool {
893 if self.latest_update_id != other.latest_update_id ||
894 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
895 self.destination_script != other.destination_script ||
896 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
897 self.counterparty_payment_script != other.counterparty_payment_script ||
898 self.keys.pubkeys() != other.keys.pubkeys() ||
899 self.funding_info != other.funding_info ||
900 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
901 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
902 self.counterparty_tx_cache != other.counterparty_tx_cache ||
903 self.funding_redeemscript != other.funding_redeemscript ||
904 self.channel_value_satoshis != other.channel_value_satoshis ||
905 self.their_cur_revocation_points != other.their_cur_revocation_points ||
906 self.on_holder_tx_csv != other.on_holder_tx_csv ||
907 self.commitment_secrets != other.commitment_secrets ||
908 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
909 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
910 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
911 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
912 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
913 self.current_holder_commitment_number != other.current_holder_commitment_number ||
914 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
915 self.payment_preimages != other.payment_preimages ||
916 self.pending_monitor_events != other.pending_monitor_events ||
917 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
918 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
919 self.outputs_to_watch != other.outputs_to_watch ||
920 self.lockdown_from_offchain != other.lockdown_from_offchain ||
921 self.holder_tx_signed != other.holder_tx_signed
930 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
931 /// Writes this monitor into the given writer, suitable for writing to disk.
933 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
934 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
935 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
936 /// returned block hash and the the current chain and then reconnecting blocks to get to the
937 /// best chain) upon deserializing the object!
938 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
939 //TODO: We still write out all the serialization here manually instead of using the fancy
940 //serialization framework we have, we should migrate things over to it.
941 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
942 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
944 self.latest_update_id.write(writer)?;
946 // Set in initial Channel-object creation, so should always be set by now:
947 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
949 self.destination_script.write(writer)?;
950 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
951 writer.write_all(&[0; 1])?;
952 broadcasted_holder_revokable_script.0.write(writer)?;
953 broadcasted_holder_revokable_script.1.write(writer)?;
954 broadcasted_holder_revokable_script.2.write(writer)?;
956 writer.write_all(&[1; 1])?;
959 self.counterparty_payment_script.write(writer)?;
960 self.shutdown_script.write(writer)?;
962 self.keys.write(writer)?;
963 writer.write_all(&self.funding_info.0.txid[..])?;
964 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
965 self.funding_info.1.write(writer)?;
966 self.current_counterparty_commitment_txid.write(writer)?;
967 self.prev_counterparty_commitment_txid.write(writer)?;
969 self.counterparty_tx_cache.write(writer)?;
970 self.funding_redeemscript.write(writer)?;
971 self.channel_value_satoshis.write(writer)?;
973 match self.their_cur_revocation_points {
974 Some((idx, pubkey, second_option)) => {
975 writer.write_all(&byte_utils::be48_to_array(idx))?;
976 writer.write_all(&pubkey.serialize())?;
977 match second_option {
978 Some(second_pubkey) => {
979 writer.write_all(&second_pubkey.serialize())?;
982 writer.write_all(&[0; 33])?;
987 writer.write_all(&byte_utils::be48_to_array(0))?;
991 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
993 self.commitment_secrets.write(writer)?;
995 macro_rules! serialize_htlc_in_commitment {
996 ($htlc_output: expr) => {
997 writer.write_all(&[$htlc_output.offered as u8; 1])?;
998 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
999 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
1000 writer.write_all(&$htlc_output.payment_hash.0[..])?;
1001 $htlc_output.transaction_output_index.write(writer)?;
1005 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
1006 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
1007 writer.write_all(&txid[..])?;
1008 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
1009 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
1010 serialize_htlc_in_commitment!(htlc_output);
1011 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1015 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
1016 for (ref txid, &(commitment_number, ref txouts)) in self.counterparty_commitment_txn_on_chain.iter() {
1017 writer.write_all(&txid[..])?;
1018 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
1019 (txouts.len() as u64).write(writer)?;
1020 for script in txouts.iter() {
1021 script.write(writer)?;
1025 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
1026 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
1027 writer.write_all(&payment_hash.0[..])?;
1028 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1031 macro_rules! serialize_holder_tx {
1032 ($holder_tx: expr) => {
1033 $holder_tx.txid.write(writer)?;
1034 writer.write_all(&$holder_tx.revocation_key.serialize())?;
1035 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
1036 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
1037 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
1038 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
1040 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
1041 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
1042 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
1043 serialize_htlc_in_commitment!(htlc_output);
1044 if let &Some(ref their_sig) = sig {
1046 writer.write_all(&their_sig.serialize_compact())?;
1050 htlc_source.write(writer)?;
1055 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
1056 writer.write_all(&[1; 1])?;
1057 serialize_holder_tx!(prev_holder_tx);
1059 writer.write_all(&[0; 1])?;
1062 serialize_holder_tx!(self.current_holder_commitment_tx);
1064 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
1065 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
1067 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1068 for payment_preimage in self.payment_preimages.values() {
1069 writer.write_all(&payment_preimage.0[..])?;
1072 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
1073 for event in self.pending_monitor_events.iter() {
1075 MonitorEvent::HTLCEvent(upd) => {
1079 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
1083 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1084 for event in self.pending_events.iter() {
1085 event.write(writer)?;
1088 self.last_block_hash.write(writer)?;
1090 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1091 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1092 writer.write_all(&byte_utils::be32_to_array(**target))?;
1093 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1094 for ev in events.iter() {
1096 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1098 htlc_update.0.write(writer)?;
1099 htlc_update.1.write(writer)?;
1101 OnchainEvent::MaturingOutput { ref descriptor } => {
1103 descriptor.write(writer)?;
1109 (self.outputs_to_watch.len() as u64).write(writer)?;
1110 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1111 txid.write(writer)?;
1112 (output_scripts.len() as u64).write(writer)?;
1113 for script in output_scripts.iter() {
1114 script.write(writer)?;
1117 self.onchain_tx_handler.write(writer)?;
1119 self.lockdown_from_offchain.write(writer)?;
1120 self.holder_tx_signed.write(writer)?;
1126 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1127 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1128 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1129 counterparty_htlc_base_key: &PublicKey, counterparty_delayed_payment_base_key: &PublicKey,
1130 on_holder_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1131 commitment_transaction_number_obscure_factor: u64,
1132 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1134 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1135 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1136 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1137 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1138 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1140 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() };
1142 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_holder_tx_csv);
1144 let holder_tx_sequence = initial_holder_commitment_tx.unsigned_tx.input[0].sequence as u64;
1145 let holder_tx_locktime = initial_holder_commitment_tx.unsigned_tx.lock_time as u64;
1146 let holder_commitment_tx = HolderSignedTx {
1147 txid: initial_holder_commitment_tx.txid(),
1148 revocation_key: initial_holder_commitment_tx.keys.revocation_key,
1149 a_htlc_key: initial_holder_commitment_tx.keys.broadcaster_htlc_key,
1150 b_htlc_key: initial_holder_commitment_tx.keys.countersignatory_htlc_key,
1151 delayed_payment_key: initial_holder_commitment_tx.keys.broadcaster_delayed_payment_key,
1152 per_commitment_point: initial_holder_commitment_tx.keys.per_commitment_point,
1153 feerate_per_kw: initial_holder_commitment_tx.feerate_per_kw,
1154 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1156 onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx);
1158 let mut outputs_to_watch = HashMap::new();
1159 outputs_to_watch.insert(funding_info.0.txid, vec![funding_info.1.clone()]);
1162 latest_update_id: 0,
1163 commitment_transaction_number_obscure_factor,
1165 destination_script: destination_script.clone(),
1166 broadcasted_holder_revokable_script: None,
1167 counterparty_payment_script,
1172 current_counterparty_commitment_txid: None,
1173 prev_counterparty_commitment_txid: None,
1175 counterparty_tx_cache,
1176 funding_redeemscript,
1177 channel_value_satoshis: channel_value_satoshis,
1178 their_cur_revocation_points: None,
1182 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1183 counterparty_claimable_outpoints: HashMap::new(),
1184 counterparty_commitment_txn_on_chain: HashMap::new(),
1185 counterparty_hash_commitment_number: HashMap::new(),
1187 prev_holder_signed_commitment_tx: None,
1188 current_holder_commitment_tx: holder_commitment_tx,
1189 current_counterparty_commitment_number: 1 << 48,
1190 current_holder_commitment_number: 0xffff_ffff_ffff - ((((holder_tx_sequence & 0xffffff) << 3*8) | (holder_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1192 payment_preimages: HashMap::new(),
1193 pending_monitor_events: Vec::new(),
1194 pending_events: Vec::new(),
1196 onchain_events_waiting_threshold_conf: HashMap::new(),
1201 lockdown_from_offchain: false,
1202 holder_tx_signed: false,
1204 last_block_hash: Default::default(),
1205 secp_ctx: Secp256k1::new(),
1209 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1210 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1211 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1212 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1213 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1214 return Err(MonitorUpdateError("Previous secret did not match new one"));
1217 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1218 // events for now-revoked/fulfilled HTLCs.
1219 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1220 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1225 if !self.payment_preimages.is_empty() {
1226 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1227 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1228 let min_idx = self.get_min_seen_secret();
1229 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1231 self.payment_preimages.retain(|&k, _| {
1232 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1233 if k == htlc.payment_hash {
1237 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1238 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1239 if k == htlc.payment_hash {
1244 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1251 counterparty_hash_commitment_number.remove(&k);
1260 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1261 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1262 /// possibly future revocation/preimage information) to claim outputs where possible.
1263 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1264 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 {
1265 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1266 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1267 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1269 for &(ref htlc, _) in &htlc_outputs {
1270 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1273 let new_txid = unsigned_commitment_tx.txid();
1274 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1275 log_trace!(logger, "New potential counterparty commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1276 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1277 self.current_counterparty_commitment_txid = Some(new_txid);
1278 self.counterparty_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1279 self.current_counterparty_commitment_number = commitment_number;
1280 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1281 match self.their_cur_revocation_points {
1282 Some(old_points) => {
1283 if old_points.0 == commitment_number + 1 {
1284 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1285 } else if old_points.0 == commitment_number + 2 {
1286 if let Some(old_second_point) = old_points.2 {
1287 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1289 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1292 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1296 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1299 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1300 for htlc in htlc_outputs {
1301 if htlc.0.transaction_output_index.is_some() {
1305 self.counterparty_tx_cache.per_htlc.insert(new_txid, htlcs);
1308 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1309 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1310 /// is important that any clones of this channel monitor (including remote clones) by kept
1311 /// up-to-date as our holder commitment transaction is updated.
1312 /// Panics if set_on_holder_tx_csv has never been called.
1313 pub(super) fn provide_latest_holder_commitment_tx_info(&mut self, commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1314 let txid = commitment_tx.txid();
1315 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1316 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1317 let mut new_holder_commitment_tx = HolderSignedTx {
1319 revocation_key: commitment_tx.keys.revocation_key,
1320 a_htlc_key: commitment_tx.keys.broadcaster_htlc_key,
1321 b_htlc_key: commitment_tx.keys.countersignatory_htlc_key,
1322 delayed_payment_key: commitment_tx.keys.broadcaster_delayed_payment_key,
1323 per_commitment_point: commitment_tx.keys.per_commitment_point,
1324 feerate_per_kw: commitment_tx.feerate_per_kw,
1325 htlc_outputs: htlc_outputs,
1327 self.onchain_tx_handler.provide_latest_holder_tx(commitment_tx);
1328 self.current_holder_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1329 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1330 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1331 if self.holder_tx_signed {
1332 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1337 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1338 /// commitment_tx_infos which contain the payment hash have been revoked.
1339 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1340 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1343 pub(super) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1344 where B::Target: BroadcasterInterface,
1347 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1348 broadcaster.broadcast_transaction(tx);
1350 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1353 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1356 /// panics if the given update is not the next update by update_id.
1357 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1358 where B::Target: BroadcasterInterface,
1361 if self.latest_update_id + 1 != updates.update_id {
1362 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1364 for update in updates.updates.drain(..) {
1366 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1367 if self.lockdown_from_offchain { panic!(); }
1368 self.provide_latest_holder_commitment_tx_info(commitment_tx, htlc_outputs)?
1370 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1371 self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1372 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1373 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1374 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1375 self.provide_secret(idx, secret)?,
1376 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1377 self.lockdown_from_offchain = true;
1378 if should_broadcast {
1379 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1381 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");
1386 self.latest_update_id = updates.update_id;
1390 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1392 pub fn get_latest_update_id(&self) -> u64 {
1393 self.latest_update_id
1396 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1397 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1401 /// Gets a list of txids, with their output scripts (in the order they appear in the
1402 /// transaction), which we must learn about spends of via block_connected().
1404 /// (C-not exported) because we have no HashMap bindings
1405 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1406 &self.outputs_to_watch
1409 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1410 /// Generally useful when deserializing as during normal operation the return values of
1411 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1412 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1414 /// (C-not exported) as there is no practical way to track lifetimes of returned values.
1415 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1416 let mut res = Vec::with_capacity(self.counterparty_commitment_txn_on_chain.len() * 2);
1417 for (ref txid, &(_, ref outputs)) in self.counterparty_commitment_txn_on_chain.iter() {
1418 for (idx, output) in outputs.iter().enumerate() {
1419 res.push(((*txid).clone(), idx as u32, output));
1425 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1426 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1428 /// [`chain::Watch::release_pending_monitor_events`]: ../../chain/trait.Watch.html#tymethod.release_pending_monitor_events
1429 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1430 let mut ret = Vec::new();
1431 mem::swap(&mut ret, &mut self.pending_monitor_events);
1435 /// Gets the list of pending events which were generated by previous actions, clearing the list
1438 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1439 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1440 /// no internal locking in ChannelMonitors.
1441 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1442 let mut ret = Vec::new();
1443 mem::swap(&mut ret, &mut self.pending_events);
1447 /// Can only fail if idx is < get_min_seen_secret
1448 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1449 self.commitment_secrets.get_secret(idx)
1452 pub(super) fn get_min_seen_secret(&self) -> u64 {
1453 self.commitment_secrets.get_min_seen_secret()
1456 pub(super) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1457 self.current_counterparty_commitment_number
1460 pub(super) fn get_cur_holder_commitment_number(&self) -> u64 {
1461 self.current_holder_commitment_number
1464 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1465 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1466 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1467 /// HTLC-Success/HTLC-Timeout transactions.
1468 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1469 /// revoked counterparty commitment tx
1470 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1471 // Most secp and related errors trying to create keys means we have no hope of constructing
1472 // a spend transaction...so we return no transactions to broadcast
1473 let mut claimable_outpoints = Vec::new();
1474 let mut watch_outputs = Vec::new();
1476 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1477 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1479 macro_rules! ignore_error {
1480 ( $thing : expr ) => {
1483 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1488 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);
1489 if commitment_number >= self.get_min_seen_secret() {
1490 let secret = self.get_secret(commitment_number).unwrap();
1491 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1492 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1493 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1494 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));
1496 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1497 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1499 // First, process non-htlc outputs (to_holder & to_counterparty)
1500 for (idx, outp) in tx.output.iter().enumerate() {
1501 if outp.script_pubkey == revokeable_p2wsh {
1502 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};
1503 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});
1507 // Then, try to find revoked htlc outputs
1508 if let Some(ref per_commitment_data) = per_commitment_option {
1509 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1510 if let Some(transaction_output_index) = htlc.transaction_output_index {
1511 if transaction_output_index as usize >= tx.output.len() ||
1512 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1513 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1515 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};
1516 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1521 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1522 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1523 // We're definitely a counterparty commitment transaction!
1524 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1525 watch_outputs.append(&mut tx.output.clone());
1526 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1528 macro_rules! check_htlc_fails {
1529 ($txid: expr, $commitment_tx: expr) => {
1530 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1531 for &(ref htlc, ref source_option) in outpoints.iter() {
1532 if let &Some(ref source) = source_option {
1533 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1534 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1535 hash_map::Entry::Occupied(mut entry) => {
1536 let e = entry.get_mut();
1537 e.retain(|ref event| {
1539 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1540 return htlc_update.0 != **source
1545 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1547 hash_map::Entry::Vacant(entry) => {
1548 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1556 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1557 check_htlc_fails!(txid, "current");
1559 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1560 check_htlc_fails!(txid, "counterparty");
1562 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1564 } else if let Some(per_commitment_data) = per_commitment_option {
1565 // While this isn't useful yet, there is a potential race where if a counterparty
1566 // revokes a state at the same time as the commitment transaction for that state is
1567 // confirmed, and the watchtower receives the block before the user, the user could
1568 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1569 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1570 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1572 watch_outputs.append(&mut tx.output.clone());
1573 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1575 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1577 macro_rules! check_htlc_fails {
1578 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1579 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1580 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1581 if let &Some(ref source) = source_option {
1582 // Check if the HTLC is present in the commitment transaction that was
1583 // broadcast, but not if it was below the dust limit, which we should
1584 // fail backwards immediately as there is no way for us to learn the
1585 // payment_preimage.
1586 // Note that if the dust limit were allowed to change between
1587 // commitment transactions we'd want to be check whether *any*
1588 // broadcastable commitment transaction has the HTLC in it, but it
1589 // cannot currently change after channel initialization, so we don't
1591 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1592 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1596 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);
1597 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1598 hash_map::Entry::Occupied(mut entry) => {
1599 let e = entry.get_mut();
1600 e.retain(|ref event| {
1602 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1603 return htlc_update.0 != **source
1608 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1610 hash_map::Entry::Vacant(entry) => {
1611 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1619 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1620 check_htlc_fails!(txid, "current", 'current_loop);
1622 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1623 check_htlc_fails!(txid, "previous", 'prev_loop);
1626 if let Some(revocation_points) = self.their_cur_revocation_points {
1627 let revocation_point_option =
1628 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1629 else if let Some(point) = revocation_points.2.as_ref() {
1630 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1632 if let Some(revocation_point) = revocation_point_option {
1633 self.counterparty_payment_script = {
1634 // Note that the Network here is ignored as we immediately drop the address for the
1635 // script_pubkey version
1636 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1637 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1640 // Then, try to find htlc outputs
1641 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1642 if let Some(transaction_output_index) = htlc.transaction_output_index {
1643 if transaction_output_index as usize >= tx.output.len() ||
1644 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1645 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1647 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1648 let aggregable = if !htlc.offered { false } else { true };
1649 if preimage.is_some() || !htlc.offered {
1650 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() };
1651 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1658 (claimable_outpoints, (commitment_txid, watch_outputs))
1661 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1662 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 {
1663 let htlc_txid = tx.txid();
1664 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1665 return (Vec::new(), None)
1668 macro_rules! ignore_error {
1669 ( $thing : expr ) => {
1672 Err(_) => return (Vec::new(), None)
1677 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1678 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1679 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1681 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1682 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 };
1683 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 });
1684 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1687 fn broadcast_by_holder_state(&self, commitment_tx: &Transaction, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, PublicKey, PublicKey)>) {
1688 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1689 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1691 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1692 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1694 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1695 if let Some(transaction_output_index) = htlc.transaction_output_index {
1696 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1697 witness_data: InputMaterial::HolderHTLC {
1698 preimage: if !htlc.offered {
1699 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1700 Some(preimage.clone())
1702 // We can't build an HTLC-Success transaction without the preimage
1706 amount: htlc.amount_msat,
1708 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1712 (claim_requests, watch_outputs, broadcasted_holder_revokable_script)
1715 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1716 /// revoked using data in holder_claimable_outpoints.
1717 /// Should not be used if check_spend_revoked_transaction succeeds.
1718 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1719 let commitment_txid = tx.txid();
1720 let mut claim_requests = Vec::new();
1721 let mut watch_outputs = Vec::new();
1723 macro_rules! wait_threshold_conf {
1724 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1725 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1726 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1727 hash_map::Entry::Occupied(mut entry) => {
1728 let e = entry.get_mut();
1729 e.retain(|ref event| {
1731 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1732 return htlc_update.0 != $source
1737 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1739 hash_map::Entry::Vacant(entry) => {
1740 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1746 macro_rules! append_onchain_update {
1747 ($updates: expr) => {
1748 claim_requests = $updates.0;
1749 watch_outputs.append(&mut $updates.1);
1750 self.broadcasted_holder_revokable_script = $updates.2;
1754 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1755 let mut is_holder_tx = false;
1757 if self.current_holder_commitment_tx.txid == commitment_txid {
1758 is_holder_tx = true;
1759 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1760 let mut res = self.broadcast_by_holder_state(tx, &self.current_holder_commitment_tx);
1761 append_onchain_update!(res);
1762 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1763 if holder_tx.txid == commitment_txid {
1764 is_holder_tx = true;
1765 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1766 let mut res = self.broadcast_by_holder_state(tx, holder_tx);
1767 append_onchain_update!(res);
1771 macro_rules! fail_dust_htlcs_after_threshold_conf {
1772 ($holder_tx: expr) => {
1773 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1774 if htlc.transaction_output_index.is_none() {
1775 if let &Some(ref source) = source {
1776 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1784 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1785 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1786 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1790 (claim_requests, (commitment_txid, watch_outputs))
1793 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1794 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1795 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1796 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1797 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1798 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1799 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1800 /// out-of-band the other node operator to coordinate with him if option is available to you.
1801 /// In any-case, choice is up to the user.
1802 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1803 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1804 self.holder_tx_signed = true;
1805 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1806 let txid = commitment_tx.txid();
1807 let mut res = vec![commitment_tx];
1808 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1809 if let Some(vout) = htlc.0.transaction_output_index {
1810 let preimage = if !htlc.0.offered {
1811 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1812 // We can't build an HTLC-Success transaction without the preimage
1816 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1817 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1822 // 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.
1823 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1829 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1830 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1831 /// revoked commitment transaction.
1832 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1833 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1834 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1835 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
1836 let txid = commitment_tx.txid();
1837 let mut res = vec![commitment_tx];
1838 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1839 if let Some(vout) = htlc.0.transaction_output_index {
1840 let preimage = if !htlc.0.offered {
1841 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1842 // We can't build an HTLC-Success transaction without the preimage
1846 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1847 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1857 /// Processes transactions in a newly connected block, which may result in any of the following:
1858 /// - update the monitor's state against resolved HTLCs
1859 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1860 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1861 /// - detect settled outputs for later spending
1862 /// - schedule and bump any in-flight claims
1864 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1865 /// [`get_outputs_to_watch`].
1867 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1868 pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<TxOut>)>
1869 where B::Target: BroadcasterInterface,
1870 F::Target: FeeEstimator,
1873 let txn_matched = self.filter_block(txdata);
1874 for tx in &txn_matched {
1875 let mut output_val = 0;
1876 for out in tx.output.iter() {
1877 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1878 output_val += out.value;
1879 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1883 let block_hash = header.block_hash();
1884 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1886 let mut watch_outputs = Vec::new();
1887 let mut claimable_outpoints = Vec::new();
1888 for tx in &txn_matched {
1889 if tx.input.len() == 1 {
1890 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1891 // commitment transactions and HTLC transactions will all only ever have one input,
1892 // which is an easy way to filter out any potential non-matching txn for lazy
1894 let prevout = &tx.input[0].previous_output;
1895 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1896 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1897 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1898 if !new_outputs.1.is_empty() {
1899 watch_outputs.push(new_outputs);
1901 if new_outpoints.is_empty() {
1902 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1903 if !new_outputs.1.is_empty() {
1904 watch_outputs.push(new_outputs);
1906 claimable_outpoints.append(&mut new_outpoints);
1908 claimable_outpoints.append(&mut new_outpoints);
1911 if let Some(&(commitment_number, _)) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1912 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1913 claimable_outpoints.append(&mut new_outpoints);
1914 if let Some(new_outputs) = new_outputs_option {
1915 watch_outputs.push(new_outputs);
1920 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1921 // can also be resolved in a few other ways which can have more than one output. Thus,
1922 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1923 self.is_resolving_htlc_output(&tx, height, &logger);
1925 self.is_paying_spendable_output(&tx, height, &logger);
1927 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1928 if should_broadcast {
1929 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() }});
1931 if should_broadcast {
1932 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1933 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1934 self.holder_tx_signed = true;
1935 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_holder_state(&commitment_tx, &self.current_holder_commitment_tx);
1936 if !new_outputs.is_empty() {
1937 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
1939 claimable_outpoints.append(&mut new_outpoints);
1942 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1945 OnchainEvent::HTLCUpdate { htlc_update } => {
1946 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1947 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1948 payment_hash: htlc_update.1,
1949 payment_preimage: None,
1950 source: htlc_update.0,
1953 OnchainEvent::MaturingOutput { descriptor } => {
1954 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1955 self.pending_events.push(Event::SpendableOutputs {
1956 outputs: vec![descriptor]
1963 self.onchain_tx_handler.block_connected(&txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1964 self.last_block_hash = block_hash;
1966 // Determine new outputs to watch by comparing against previously known outputs to watch,
1967 // updating the latter in the process.
1968 watch_outputs.retain(|&(ref txid, ref txouts)| {
1969 let output_scripts = txouts.iter().map(|o| o.script_pubkey.clone()).collect();
1970 self.outputs_to_watch.insert(txid.clone(), output_scripts).is_none()
1975 /// Determines if the disconnected block contained any transactions of interest and updates
1977 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
1978 where B::Target: BroadcasterInterface,
1979 F::Target: FeeEstimator,
1982 let block_hash = header.block_hash();
1983 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1985 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1987 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1988 //- maturing spendable output has transaction paying us has been disconnected
1991 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1993 self.last_block_hash = block_hash;
1996 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
1997 /// transactions thereof.
1998 fn filter_block<'a>(&self, txdata: &[(usize, &'a Transaction)]) -> Vec<&'a Transaction> {
1999 let mut matched_txn = HashSet::new();
2000 txdata.iter().filter(|&&(_, tx)| {
2001 let mut matches = self.spends_watched_output(tx);
2002 for input in tx.input.iter() {
2003 if matches { break; }
2004 if matched_txn.contains(&input.previous_output.txid) {
2009 matched_txn.insert(tx.txid());
2012 }).map(|(_, tx)| *tx).collect()
2015 /// Checks if a given transaction spends any watched outputs.
2016 fn spends_watched_output(&self, tx: &Transaction) -> bool {
2017 for input in tx.input.iter() {
2018 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2019 for (idx, _script_pubkey) in outputs.iter().enumerate() {
2020 if idx == input.previous_output.vout as usize {
2030 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2031 // We need to consider all HTLCs which are:
2032 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2033 // transactions and we'd end up in a race, or
2034 // * are in our latest holder commitment transaction, as this is the thing we will
2035 // broadcast if we go on-chain.
2036 // Note that we consider HTLCs which were below dust threshold here - while they don't
2037 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2038 // to the source, and if we don't fail the channel we will have to ensure that the next
2039 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2040 // easier to just fail the channel as this case should be rare enough anyway.
2041 macro_rules! scan_commitment {
2042 ($htlcs: expr, $holder_tx: expr) => {
2043 for ref htlc in $htlcs {
2044 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2045 // chain with enough room to claim the HTLC without our counterparty being able to
2046 // time out the HTLC first.
2047 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2048 // concern is being able to claim the corresponding inbound HTLC (on another
2049 // channel) before it expires. In fact, we don't even really care if our
2050 // counterparty here claims such an outbound HTLC after it expired as long as we
2051 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2052 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2053 // we give ourselves a few blocks of headroom after expiration before going
2054 // on-chain for an expired HTLC.
2055 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2056 // from us until we've reached the point where we go on-chain with the
2057 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2058 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2059 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2060 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2061 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2062 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2063 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2064 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2065 // The final, above, condition is checked for statically in channelmanager
2066 // with CHECK_CLTV_EXPIRY_SANITY_2.
2067 let htlc_outbound = $holder_tx == htlc.offered;
2068 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2069 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2070 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2077 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2079 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2080 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2081 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2084 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2085 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2086 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2093 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2094 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2095 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2096 'outer_loop: for input in &tx.input {
2097 let mut payment_data = None;
2098 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2099 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2100 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2101 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2103 macro_rules! log_claim {
2104 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2105 // We found the output in question, but aren't failing it backwards
2106 // as we have no corresponding source and no valid counterparty commitment txid
2107 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2108 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2109 let outbound_htlc = $holder_tx == $htlc.offered;
2110 if ($holder_tx && revocation_sig_claim) ||
2111 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2112 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2113 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2114 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2115 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2117 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2118 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2119 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2120 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2125 macro_rules! check_htlc_valid_counterparty {
2126 ($counterparty_txid: expr, $htlc_output: expr) => {
2127 if let Some(txid) = $counterparty_txid {
2128 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2129 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2130 if let &Some(ref source) = pending_source {
2131 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2132 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2141 macro_rules! scan_commitment {
2142 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2143 for (ref htlc_output, source_option) in $htlcs {
2144 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2145 if let Some(ref source) = source_option {
2146 log_claim!($tx_info, $holder_tx, htlc_output, true);
2147 // We have a resolution of an HTLC either from one of our latest
2148 // holder commitment transactions or an unrevoked counterparty commitment
2149 // transaction. This implies we either learned a preimage, the HTLC
2150 // has timed out, or we screwed up. In any case, we should now
2151 // resolve the source HTLC with the original sender.
2152 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2153 } else if !$holder_tx {
2154 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2155 if payment_data.is_none() {
2156 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2159 if payment_data.is_none() {
2160 log_claim!($tx_info, $holder_tx, htlc_output, false);
2161 continue 'outer_loop;
2168 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2169 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2170 "our latest holder commitment tx", true);
2172 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2173 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2174 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2175 "our previous holder commitment tx", true);
2178 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2179 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2180 "counterparty commitment tx", false);
2183 // Check that scan_commitment, above, decided there is some source worth relaying an
2184 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2185 if let Some((source, payment_hash)) = payment_data {
2186 let mut payment_preimage = PaymentPreimage([0; 32]);
2187 if accepted_preimage_claim {
2188 if !self.pending_monitor_events.iter().any(
2189 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2190 payment_preimage.0.copy_from_slice(&input.witness[3]);
2191 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2193 payment_preimage: Some(payment_preimage),
2197 } else if offered_preimage_claim {
2198 if !self.pending_monitor_events.iter().any(
2199 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2200 upd.source == source
2202 payment_preimage.0.copy_from_slice(&input.witness[1]);
2203 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2205 payment_preimage: Some(payment_preimage),
2210 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);
2211 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2212 hash_map::Entry::Occupied(mut entry) => {
2213 let e = entry.get_mut();
2214 e.retain(|ref event| {
2216 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2217 return htlc_update.0 != source
2222 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2224 hash_map::Entry::Vacant(entry) => {
2225 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2233 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2234 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2235 let mut spendable_output = None;
2236 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2237 if i > ::std::u16::MAX as usize {
2238 // While it is possible that an output exists on chain which is greater than the
2239 // 2^16th output in a given transaction, this is only possible if the output is not
2240 // in a lightning transaction and was instead placed there by some third party who
2241 // wishes to give us money for no reason.
2242 // Namely, any lightning transactions which we pre-sign will never have anywhere
2243 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2244 // scripts are not longer than one byte in length and because they are inherently
2245 // non-standard due to their size.
2246 // Thus, it is completely safe to ignore such outputs, and while it may result in
2247 // us ignoring non-lightning fund to us, that is only possible if someone fills
2248 // nearly a full block with garbage just to hit this case.
2251 if outp.script_pubkey == self.destination_script {
2252 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2253 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2254 output: outp.clone(),
2257 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2258 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2259 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2260 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2261 per_commitment_point: broadcasted_holder_revokable_script.1,
2262 to_self_delay: self.on_holder_tx_csv,
2263 output: outp.clone(),
2264 key_derivation_params: self.keys.key_derivation_params(),
2265 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2269 } else if self.counterparty_payment_script == outp.script_pubkey {
2270 spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
2271 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2272 output: outp.clone(),
2273 key_derivation_params: self.keys.key_derivation_params(),
2276 } else if outp.script_pubkey == self.shutdown_script {
2277 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2278 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2279 output: outp.clone(),
2283 if let Some(spendable_output) = spendable_output {
2284 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2285 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2286 hash_map::Entry::Occupied(mut entry) => {
2287 let e = entry.get_mut();
2288 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2290 hash_map::Entry::Vacant(entry) => {
2291 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2298 const MAX_ALLOC_SIZE: usize = 64*1024;
2300 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2301 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2302 macro_rules! unwrap_obj {
2306 Err(_) => return Err(DecodeError::InvalidValue),
2311 let _ver: u8 = Readable::read(reader)?;
2312 let min_ver: u8 = Readable::read(reader)?;
2313 if min_ver > SERIALIZATION_VERSION {
2314 return Err(DecodeError::UnknownVersion);
2317 let latest_update_id: u64 = Readable::read(reader)?;
2318 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2320 let destination_script = Readable::read(reader)?;
2321 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2323 let revokable_address = Readable::read(reader)?;
2324 let per_commitment_point = Readable::read(reader)?;
2325 let revokable_script = Readable::read(reader)?;
2326 Some((revokable_address, per_commitment_point, revokable_script))
2329 _ => return Err(DecodeError::InvalidValue),
2331 let counterparty_payment_script = Readable::read(reader)?;
2332 let shutdown_script = Readable::read(reader)?;
2334 let keys = Readable::read(reader)?;
2335 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2336 // barely-init'd ChannelMonitors that we can't do anything with.
2337 let outpoint = OutPoint {
2338 txid: Readable::read(reader)?,
2339 index: Readable::read(reader)?,
2341 let funding_info = (outpoint, Readable::read(reader)?);
2342 let current_counterparty_commitment_txid = Readable::read(reader)?;
2343 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2345 let counterparty_tx_cache = Readable::read(reader)?;
2346 let funding_redeemscript = Readable::read(reader)?;
2347 let channel_value_satoshis = Readable::read(reader)?;
2349 let their_cur_revocation_points = {
2350 let first_idx = <U48 as Readable>::read(reader)?.0;
2354 let first_point = Readable::read(reader)?;
2355 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2356 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2357 Some((first_idx, first_point, None))
2359 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2364 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2366 let commitment_secrets = Readable::read(reader)?;
2368 macro_rules! read_htlc_in_commitment {
2371 let offered: bool = Readable::read(reader)?;
2372 let amount_msat: u64 = Readable::read(reader)?;
2373 let cltv_expiry: u32 = Readable::read(reader)?;
2374 let payment_hash: PaymentHash = Readable::read(reader)?;
2375 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2377 HTLCOutputInCommitment {
2378 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2384 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2385 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2386 for _ in 0..counterparty_claimable_outpoints_len {
2387 let txid: Txid = Readable::read(reader)?;
2388 let htlcs_count: u64 = Readable::read(reader)?;
2389 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2390 for _ in 0..htlcs_count {
2391 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2393 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2394 return Err(DecodeError::InvalidValue);
2398 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2399 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2400 for _ in 0..counterparty_commitment_txn_on_chain_len {
2401 let txid: Txid = Readable::read(reader)?;
2402 let commitment_number = <U48 as Readable>::read(reader)?.0;
2403 let outputs_count = <u64 as Readable>::read(reader)?;
2404 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2405 for _ in 0..outputs_count {
2406 outputs.push(Readable::read(reader)?);
2408 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2409 return Err(DecodeError::InvalidValue);
2413 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2414 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2415 for _ in 0..counterparty_hash_commitment_number_len {
2416 let payment_hash: PaymentHash = Readable::read(reader)?;
2417 let commitment_number = <U48 as Readable>::read(reader)?.0;
2418 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2419 return Err(DecodeError::InvalidValue);
2423 macro_rules! read_holder_tx {
2426 let txid = Readable::read(reader)?;
2427 let revocation_key = Readable::read(reader)?;
2428 let a_htlc_key = Readable::read(reader)?;
2429 let b_htlc_key = Readable::read(reader)?;
2430 let delayed_payment_key = Readable::read(reader)?;
2431 let per_commitment_point = Readable::read(reader)?;
2432 let feerate_per_kw: u32 = Readable::read(reader)?;
2434 let htlcs_len: u64 = Readable::read(reader)?;
2435 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2436 for _ in 0..htlcs_len {
2437 let htlc = read_htlc_in_commitment!();
2438 let sigs = match <u8 as Readable>::read(reader)? {
2440 1 => Some(Readable::read(reader)?),
2441 _ => return Err(DecodeError::InvalidValue),
2443 htlcs.push((htlc, sigs, Readable::read(reader)?));
2448 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2455 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2458 Some(read_holder_tx!())
2460 _ => return Err(DecodeError::InvalidValue),
2462 let current_holder_commitment_tx = read_holder_tx!();
2464 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2465 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2467 let payment_preimages_len: u64 = Readable::read(reader)?;
2468 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2469 for _ in 0..payment_preimages_len {
2470 let preimage: PaymentPreimage = Readable::read(reader)?;
2471 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2472 if let Some(_) = payment_preimages.insert(hash, preimage) {
2473 return Err(DecodeError::InvalidValue);
2477 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2478 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2479 for _ in 0..pending_monitor_events_len {
2480 let ev = match <u8 as Readable>::read(reader)? {
2481 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2482 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2483 _ => return Err(DecodeError::InvalidValue)
2485 pending_monitor_events.push(ev);
2488 let pending_events_len: u64 = Readable::read(reader)?;
2489 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2490 for _ in 0..pending_events_len {
2491 if let Some(event) = MaybeReadable::read(reader)? {
2492 pending_events.push(event);
2496 let last_block_hash: BlockHash = Readable::read(reader)?;
2498 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2499 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2500 for _ in 0..waiting_threshold_conf_len {
2501 let height_target = Readable::read(reader)?;
2502 let events_len: u64 = Readable::read(reader)?;
2503 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2504 for _ in 0..events_len {
2505 let ev = match <u8 as Readable>::read(reader)? {
2507 let htlc_source = Readable::read(reader)?;
2508 let hash = Readable::read(reader)?;
2509 OnchainEvent::HTLCUpdate {
2510 htlc_update: (htlc_source, hash)
2514 let descriptor = Readable::read(reader)?;
2515 OnchainEvent::MaturingOutput {
2519 _ => return Err(DecodeError::InvalidValue),
2523 onchain_events_waiting_threshold_conf.insert(height_target, events);
2526 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2527 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>>())));
2528 for _ in 0..outputs_to_watch_len {
2529 let txid = Readable::read(reader)?;
2530 let outputs_len: u64 = Readable::read(reader)?;
2531 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2532 for _ in 0..outputs_len {
2533 outputs.push(Readable::read(reader)?);
2535 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2536 return Err(DecodeError::InvalidValue);
2539 let onchain_tx_handler = Readable::read(reader)?;
2541 let lockdown_from_offchain = Readable::read(reader)?;
2542 let holder_tx_signed = Readable::read(reader)?;
2544 Ok((last_block_hash.clone(), ChannelMonitor {
2546 commitment_transaction_number_obscure_factor,
2549 broadcasted_holder_revokable_script,
2550 counterparty_payment_script,
2555 current_counterparty_commitment_txid,
2556 prev_counterparty_commitment_txid,
2558 counterparty_tx_cache,
2559 funding_redeemscript,
2560 channel_value_satoshis,
2561 their_cur_revocation_points,
2566 counterparty_claimable_outpoints,
2567 counterparty_commitment_txn_on_chain,
2568 counterparty_hash_commitment_number,
2570 prev_holder_signed_commitment_tx,
2571 current_holder_commitment_tx,
2572 current_counterparty_commitment_number,
2573 current_holder_commitment_number,
2576 pending_monitor_events,
2579 onchain_events_waiting_threshold_conf,
2584 lockdown_from_offchain,
2588 secp_ctx: Secp256k1::new(),
2595 use bitcoin::blockdata::script::{Script, Builder};
2596 use bitcoin::blockdata::opcodes;
2597 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2598 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2599 use bitcoin::util::bip143;
2600 use bitcoin::hashes::Hash;
2601 use bitcoin::hashes::sha256::Hash as Sha256;
2602 use bitcoin::hashes::hex::FromHex;
2603 use bitcoin::hash_types::Txid;
2605 use chain::transaction::OutPoint;
2606 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2607 use ln::channelmonitor::ChannelMonitor;
2608 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2610 use ln::chan_utils::{HTLCOutputInCommitment, HolderCommitmentTransaction};
2611 use util::test_utils::TestLogger;
2612 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2613 use bitcoin::secp256k1::Secp256k1;
2615 use chain::keysinterface::InMemoryChannelKeys;
2618 fn test_prune_preimages() {
2619 let secp_ctx = Secp256k1::new();
2620 let logger = Arc::new(TestLogger::new());
2622 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2623 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2625 let mut preimages = Vec::new();
2628 let preimage = PaymentPreimage([i; 32]);
2629 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2630 preimages.push((preimage, hash));
2634 macro_rules! preimages_slice_to_htlc_outputs {
2635 ($preimages_slice: expr) => {
2637 let mut res = Vec::new();
2638 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2639 res.push((HTLCOutputInCommitment {
2643 payment_hash: preimage.1.clone(),
2644 transaction_output_index: Some(idx as u32),
2651 macro_rules! preimages_to_holder_htlcs {
2652 ($preimages_slice: expr) => {
2654 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2655 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2661 macro_rules! test_preimages_exist {
2662 ($preimages_slice: expr, $monitor: expr) => {
2663 for preimage in $preimages_slice {
2664 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2669 let keys = InMemoryChannelKeys::new(
2671 SecretKey::from_slice(&[41; 32]).unwrap(),
2672 SecretKey::from_slice(&[41; 32]).unwrap(),
2673 SecretKey::from_slice(&[41; 32]).unwrap(),
2674 SecretKey::from_slice(&[41; 32]).unwrap(),
2675 SecretKey::from_slice(&[41; 32]).unwrap(),
2681 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2683 let mut monitor = ChannelMonitor::new(keys,
2684 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2685 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2686 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2687 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2688 10, Script::new(), 46, 0, HolderCommitmentTransaction::dummy());
2690 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2691 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2692 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2693 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2694 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2695 for &(ref preimage, ref hash) in preimages.iter() {
2696 monitor.provide_payment_preimage(hash, preimage);
2699 // Now provide a secret, pruning preimages 10-15
2700 let mut secret = [0; 32];
2701 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2702 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2703 assert_eq!(monitor.payment_preimages.len(), 15);
2704 test_preimages_exist!(&preimages[0..10], monitor);
2705 test_preimages_exist!(&preimages[15..20], monitor);
2707 // Now provide a further secret, pruning preimages 15-17
2708 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2709 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2710 assert_eq!(monitor.payment_preimages.len(), 13);
2711 test_preimages_exist!(&preimages[0..10], monitor);
2712 test_preimages_exist!(&preimages[17..20], monitor);
2714 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2715 // previous commitment tx's preimages too
2716 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2717 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2718 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2719 assert_eq!(monitor.payment_preimages.len(), 12);
2720 test_preimages_exist!(&preimages[0..10], monitor);
2721 test_preimages_exist!(&preimages[18..20], monitor);
2723 // But if we do it again, we'll prune 5-10
2724 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2725 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2726 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2727 assert_eq!(monitor.payment_preimages.len(), 5);
2728 test_preimages_exist!(&preimages[0..5], monitor);
2732 fn test_claim_txn_weight_computation() {
2733 // We test Claim txn weight, knowing that we want expected weigth and
2734 // not actual case to avoid sigs and time-lock delays hell variances.
2736 let secp_ctx = Secp256k1::new();
2737 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2738 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2739 let mut sum_actual_sigs = 0;
2741 macro_rules! sign_input {
2742 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2743 let htlc = HTLCOutputInCommitment {
2744 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2746 cltv_expiry: 2 << 16,
2747 payment_hash: PaymentHash([1; 32]),
2748 transaction_output_index: Some($idx as u32),
2750 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2751 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2752 let sig = secp_ctx.sign(&sighash, &privkey);
2753 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2754 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2755 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2756 if *$input_type == InputDescriptors::RevokedOutput {
2757 $sighash_parts.access_witness($idx).push(vec!(1));
2758 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2759 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2760 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2761 $sighash_parts.access_witness($idx).push(vec![0]);
2763 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2765 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2766 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2767 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2768 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2772 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2773 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2775 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2776 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2778 claim_tx.input.push(TxIn {
2779 previous_output: BitcoinOutPoint {
2783 script_sig: Script::new(),
2784 sequence: 0xfffffffd,
2785 witness: Vec::new(),
2788 claim_tx.output.push(TxOut {
2789 script_pubkey: script_pubkey.clone(),
2792 let base_weight = claim_tx.get_weight();
2793 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2795 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2796 for (idx, inp) in inputs_des.iter().enumerate() {
2797 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2800 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));
2802 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2803 claim_tx.input.clear();
2804 sum_actual_sigs = 0;
2806 claim_tx.input.push(TxIn {
2807 previous_output: BitcoinOutPoint {
2811 script_sig: Script::new(),
2812 sequence: 0xfffffffd,
2813 witness: Vec::new(),
2816 let base_weight = claim_tx.get_weight();
2817 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2819 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2820 for (idx, inp) in inputs_des.iter().enumerate() {
2821 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2824 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));
2826 // Justice tx with 1 revoked HTLC-Success tx output
2827 claim_tx.input.clear();
2828 sum_actual_sigs = 0;
2829 claim_tx.input.push(TxIn {
2830 previous_output: BitcoinOutPoint {
2834 script_sig: Script::new(),
2835 sequence: 0xfffffffd,
2836 witness: Vec::new(),
2838 let base_weight = claim_tx.get_weight();
2839 let inputs_des = vec![InputDescriptors::RevokedOutput];
2841 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2842 for (idx, inp) in inputs_des.iter().enumerate() {
2843 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2846 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));
2849 // Further testing is done in the ChannelManager integration tests.