1 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
4 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
5 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
6 //! be made in responding to certain messages, see ManyChannelMonitor for more.
8 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
9 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
10 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
11 //! security-domain-separated system design, you should consider having multiple paths for
12 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
14 use bitcoin::blockdata::block::BlockHeader;
15 use bitcoin::blockdata::transaction::{TxOut,Transaction};
16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
17 use bitcoin::blockdata::script::{Script, Builder};
18 use bitcoin::blockdata::opcodes;
19 use bitcoin::consensus::encode;
20 use bitcoin::util::hash::BitcoinHash;
22 use bitcoin::hashes::Hash;
23 use bitcoin::hashes::sha256::Hash as Sha256;
24 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
26 use bitcoin::secp256k1::{Secp256k1,Signature};
27 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
28 use bitcoin::secp256k1;
30 use ln::msgs::DecodeError;
32 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
33 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
34 use ln::onchaintx::OnchainTxHandler;
35 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator};
36 use chain::transaction::OutPoint;
37 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
38 use util::logger::Logger;
39 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
40 use util::{byte_utils, events};
42 use std::collections::{HashMap, hash_map};
43 use std::sync::{Mutex, MutexGuard};
44 use std::{hash,cmp, mem};
47 /// An update generated by the underlying Channel itself which contains some new information the
48 /// ChannelMonitor should be made aware of.
49 #[cfg_attr(test, derive(PartialEq))]
52 pub struct ChannelMonitorUpdate {
53 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
54 /// The sequence number of this update. Updates *must* be replayed in-order according to this
55 /// sequence number (and updates may panic if they are not). The update_id values are strictly
56 /// increasing and increase by one for each new update.
58 /// This sequence number is also used to track up to which points updates which returned
59 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
60 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
64 impl Writeable for ChannelMonitorUpdate {
65 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
66 self.update_id.write(w)?;
67 (self.updates.len() as u64).write(w)?;
68 for update_step in self.updates.iter() {
69 update_step.write(w)?;
74 impl Readable for ChannelMonitorUpdate {
75 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
76 let update_id: u64 = Readable::read(r)?;
77 let len: u64 = Readable::read(r)?;
78 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
80 updates.push(Readable::read(r)?);
82 Ok(Self { update_id, updates })
86 /// An error enum representing a failure to persist a channel monitor update.
88 pub enum ChannelMonitorUpdateErr {
89 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
90 /// our state failed, but is expected to succeed at some point in the future).
92 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
93 /// submitting new commitment transactions to the remote party. Once the update(s) which failed
94 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
95 /// restore the channel to an operational state.
97 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
98 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
99 /// writing out the latest ChannelManager state.
101 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
102 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
103 /// to claim it on this channel) and those updates must be applied wherever they can be. At
104 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
105 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
106 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
109 /// Note that even if updates made after TemporaryFailure succeed you must still call
110 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
113 /// Note that the update being processed here will not be replayed for you when you call
114 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
115 /// with the persisted ChannelMonitor on your own local disk prior to returning a
116 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
117 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
120 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
121 /// remote location (with local copies persisted immediately), it is anticipated that all
122 /// updates will return TemporaryFailure until the remote copies could be updated.
124 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
125 /// different watchtower and cannot update with all watchtowers that were previously informed
126 /// of this channel). This will force-close the channel in question (which will generate one
127 /// final ChannelMonitorUpdate which must be delivered to at least one ChannelMonitor copy).
129 /// Should also be used to indicate a failure to update the local persisted copy of the channel
134 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
135 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
136 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
138 /// Contains a human-readable error message.
140 pub struct MonitorUpdateError(pub &'static str);
142 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
143 /// forward channel and from which info are needed to update HTLC in a backward channel.
144 #[derive(Clone, PartialEq)]
145 pub struct HTLCUpdate {
146 pub(super) payment_hash: PaymentHash,
147 pub(super) payment_preimage: Option<PaymentPreimage>,
148 pub(super) source: HTLCSource
150 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
152 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
153 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
154 /// events to it, while also taking any add/update_monitor events and passing them to some remote
157 /// In general, you must always have at least one local copy in memory, which must never fail to
158 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
159 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
160 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
161 /// taking any further action such as writing the current state to disk. This should likely be
162 /// accomplished via panic!() or abort().
164 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
165 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
166 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
167 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
169 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
170 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
171 /// than calling these methods directly, the user should register implementors as listeners to the
172 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
173 /// all registered listeners in one go.
174 pub trait ManyChannelMonitor<ChanSigner: ChannelKeys>: Send + Sync {
175 /// Adds a monitor for the given `funding_txo`.
177 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
178 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
179 /// callbacks with the funding transaction, or any spends of it.
181 /// Further, the implementer must also ensure that each output returned in
182 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
183 /// any spends of any of the outputs.
185 /// Any spends of outputs which should have been registered which aren't passed to
186 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
187 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr>;
189 /// Updates a monitor for the given `funding_txo`.
191 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
192 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
193 /// callbacks with the funding transaction, or any spends of it.
195 /// Further, the implementer must also ensure that each output returned in
196 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
197 /// any spends of any of the outputs.
199 /// Any spends of outputs which should have been registered which aren't passed to
200 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
201 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
203 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
204 /// with success or failure.
206 /// You should probably just call through to
207 /// ChannelMonitor::get_and_clear_pending_htlcs_updated() for each ChannelMonitor and return
209 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate>;
212 /// A lock held on a specific ManyChannelMonitor that includes a reference to the current version
213 /// of a ChannelMonitor contained within.
214 pub struct ManyChannelMonitorLock<'a, Key, ChanSigner: ChannelKeys> {
215 lock_ptr: *mut MutexGuard<'a, HashMap<Key, ChannelMonitor<ChanSigner>>>,
216 monitor: &'a ChannelMonitor<ChanSigner>,
218 impl<'a, Key, ChanSigner: ChannelKeys> ::std::ops::Deref for ManyChannelMonitorLock<'a, Key, ChanSigner> {
219 type Target = ChannelMonitor<ChanSigner>;
220 fn deref(&self) -> &ChannelMonitor<ChanSigner> {
224 impl<'a, Key, ChanSigner: ChannelKeys> Drop for ManyChannelMonitorLock<'a, Key, ChanSigner> {
226 // Dereferencing the lock_ptr is trivially safe here - it is created when this object is
227 // created, is never null, and is not modified at any point other than creation.
228 let _ = unsafe { Box::from_raw(self.lock_ptr) };
229 // Drop the box, freeing the lock
233 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
234 /// watchtower or watch our own channels.
236 /// Note that you must provide your own key by which to refer to channels.
238 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
239 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
240 /// index by a PublicKey which is required to sign any updates.
242 /// If you're using this for local monitoring of your own channels, you probably want to use
243 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
244 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref>
245 where T::Target: BroadcasterInterface,
246 F::Target: FeeEstimator,
248 C::Target: ChainWatchInterface,
250 #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
251 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
253 monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
260 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send>
261 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
262 where T::Target: BroadcasterInterface,
263 F::Target: FeeEstimator,
265 C::Target: ChainWatchInterface,
267 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
268 let block_hash = header.bitcoin_hash();
270 let mut monitors = self.monitors.lock().unwrap();
271 for monitor in monitors.values_mut() {
272 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
274 for (ref txid, ref outputs) in txn_outputs {
275 for (idx, output) in outputs.iter().enumerate() {
276 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
283 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
284 let block_hash = header.bitcoin_hash();
285 let mut monitors = self.monitors.lock().unwrap();
286 for monitor in monitors.values_mut() {
287 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
292 impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
293 where T::Target: BroadcasterInterface,
294 F::Target: FeeEstimator,
296 C::Target: ChainWatchInterface,
298 /// Creates a new object which can be used to monitor several channels given the chain
299 /// interface with which to register to receive notifications.
300 pub fn new(chain_monitor: C, broadcaster: T, logger: L, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C> {
301 let res = SimpleManyChannelMonitor {
302 monitors: Mutex::new(HashMap::new()),
306 fee_estimator: feeest,
312 /// Adds or updates the monitor which monitors the channel referred to by the given key.
313 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
314 let mut monitors = self.monitors.lock().unwrap();
315 let entry = match monitors.entry(key) {
316 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
317 hash_map::Entry::Vacant(e) => e,
319 log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(monitor.funding_info.0.to_channel_id()[..]));
320 self.chain_monitor.install_watch_tx(&monitor.funding_info.0.txid, &monitor.funding_info.1);
321 self.chain_monitor.install_watch_outpoint((monitor.funding_info.0.txid, monitor.funding_info.0.index as u32), &monitor.funding_info.1);
322 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
323 for (idx, script) in outputs.iter().enumerate() {
324 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
327 entry.insert(monitor);
331 /// Updates the monitor which monitors the channel referred to by the given key.
332 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
333 let mut monitors = self.monitors.lock().unwrap();
334 match monitors.get_mut(&key) {
335 Some(orig_monitor) => {
336 log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
337 orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
339 None => Err(MonitorUpdateError("No such monitor registered"))
343 /// Gets a reference to the latest copy of a given ChannelMonitor given a &Key, if any has been
346 /// The returned value contains a lock on this object, and other calls into this object will
347 /// almost certainly block until the returned value is dropped!
348 pub fn get_monitor_ref_by_key<'a>(&'a self, key: &Key) -> Option<ManyChannelMonitorLock<'a, Key, ChanSigner>> {
349 // Rust doesn't natively allow self-referential structs, and the only way to return a
350 // reference to something inside our Mutex is to return a struct that contains the lock and
351 // a reference to something pulled out of said lock.
352 // To avoid this, we have to fall back to some use of unsafe, but luckily its incredibly
353 // trivial - we simply Box up the MutexGuard and Box::leak() it, ensuring that its sitting
354 // in our heap without Rust having any reference to drop it.
355 // Then, we do a map lookup against the raw pointer, either returning a
356 // ManyChannelMonitorMonRef (which will drop the lock by recreating the Box when it gets
357 // dropped), or we will recreate the Box immediately and drop the lock before returning
360 // The returned ManyChannelMonitorMonRef is templated by a lifetime for which &self is
361 // valid, ensuring this object cannot be dropped until after the returned value is.
362 let lock = Box::new(self.monitors.lock().unwrap());
363 let lock_ptr: *mut MutexGuard<HashMap<Key, ChannelMonitor<ChanSigner>>> = Box::leak(lock);
364 let mon = unsafe { (*lock_ptr).get(key) };
365 if let Some(monitor) = mon {
366 Some(ManyChannelMonitorLock { lock_ptr, monitor })
368 let _ = unsafe { Box::from_raw(lock_ptr) };
369 // Drop the lock again
375 impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, C: Deref + Sync + Send> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F, L, C>
376 where T::Target: BroadcasterInterface,
377 F::Target: FeeEstimator,
379 C::Target: ChainWatchInterface,
381 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
382 match self.add_monitor_by_key(funding_txo, monitor) {
384 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
388 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
389 match self.update_monitor_by_key(funding_txo, update) {
391 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
395 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {
396 let mut pending_htlcs_updated = Vec::new();
397 for chan in self.monitors.lock().unwrap().values_mut() {
398 pending_htlcs_updated.append(&mut chan.get_and_clear_pending_htlcs_updated());
400 pending_htlcs_updated
404 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref, C: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F, L, C>
405 where T::Target: BroadcasterInterface,
406 F::Target: FeeEstimator,
408 C::Target: ChainWatchInterface,
410 fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
411 let mut pending_events = Vec::new();
412 for chan in self.monitors.lock().unwrap().values_mut() {
413 pending_events.append(&mut chan.get_and_clear_pending_events());
419 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
420 /// instead claiming it in its own individual transaction.
421 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
422 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
423 /// HTLC-Success transaction.
424 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
425 /// transaction confirmed (and we use it in a few more, equivalent, places).
426 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
427 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
428 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
429 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
430 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
431 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
432 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
433 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
434 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
435 /// accurate block height.
436 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
437 /// with at worst this delay, so we are not only using this value as a mercy for them but also
438 /// us as a safeguard to delay with enough time.
439 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
440 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
441 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
442 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
443 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
444 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
445 /// keeping bumping another claim tx to solve the outpoint.
446 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
447 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
448 /// refuse to accept a new HTLC.
450 /// This is used for a few separate purposes:
451 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
452 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
454 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
455 /// condition with the above), we will fail this HTLC without telling the user we received it,
456 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
457 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
459 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
460 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
462 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
463 /// in a race condition between the user connecting a block (which would fail it) and the user
464 /// providing us the preimage (which would claim it).
466 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
467 /// end up force-closing the channel on us to claim it.
468 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
470 #[derive(Clone, PartialEq)]
471 struct LocalSignedTx {
472 /// txid of the transaction in tx, just used to make comparison faster
474 revocation_key: PublicKey,
475 a_htlc_key: PublicKey,
476 b_htlc_key: PublicKey,
477 delayed_payment_key: PublicKey,
478 per_commitment_point: PublicKey,
480 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
483 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
484 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
485 /// a new bumped one in case of lenghty confirmation delay
486 #[derive(Clone, PartialEq)]
487 pub(crate) enum InputMaterial {
489 witness_script: Script,
490 pubkey: Option<PublicKey>,
496 witness_script: Script,
498 preimage: Option<PaymentPreimage>,
503 preimage: Option<PaymentPreimage>,
507 funding_redeemscript: Script,
511 impl Writeable for InputMaterial {
512 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
514 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount} => {
515 writer.write_all(&[0; 1])?;
516 witness_script.write(writer)?;
517 pubkey.write(writer)?;
518 writer.write_all(&key[..])?;
519 is_htlc.write(writer)?;
520 writer.write_all(&byte_utils::be64_to_array(*amount))?;
522 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
523 writer.write_all(&[1; 1])?;
524 witness_script.write(writer)?;
526 preimage.write(writer)?;
527 writer.write_all(&byte_utils::be64_to_array(*amount))?;
528 writer.write_all(&byte_utils::be32_to_array(*locktime))?;
530 &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
531 writer.write_all(&[2; 1])?;
532 preimage.write(writer)?;
533 writer.write_all(&byte_utils::be64_to_array(*amount))?;
535 &InputMaterial::Funding { ref funding_redeemscript } => {
536 writer.write_all(&[3; 1])?;
537 funding_redeemscript.write(writer)?;
544 impl Readable for InputMaterial {
545 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
546 let input_material = match <u8 as Readable>::read(reader)? {
548 let witness_script = Readable::read(reader)?;
549 let pubkey = Readable::read(reader)?;
550 let key = Readable::read(reader)?;
551 let is_htlc = Readable::read(reader)?;
552 let amount = Readable::read(reader)?;
553 InputMaterial::Revoked {
562 let witness_script = Readable::read(reader)?;
563 let key = Readable::read(reader)?;
564 let preimage = Readable::read(reader)?;
565 let amount = Readable::read(reader)?;
566 let locktime = Readable::read(reader)?;
567 InputMaterial::RemoteHTLC {
576 let preimage = Readable::read(reader)?;
577 let amount = Readable::read(reader)?;
578 InputMaterial::LocalHTLC {
584 InputMaterial::Funding {
585 funding_redeemscript: Readable::read(reader)?,
588 _ => return Err(DecodeError::InvalidValue),
594 /// ClaimRequest is a descriptor structure to communicate between detection
595 /// and reaction module. They are generated by ChannelMonitor while parsing
596 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
597 /// is responsible for opportunistic aggregation, selecting and enforcing
598 /// bumping logic, building and signing transactions.
599 pub(crate) struct ClaimRequest {
600 // Block height before which claiming is exclusive to one party,
601 // after reaching it, claiming may be contentious.
602 pub(crate) absolute_timelock: u32,
603 // Timeout tx must have nLocktime set which means aggregating multiple
604 // ones must take the higher nLocktime among them to satisfy all of them.
605 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
606 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
607 // Do simplify we mark them as non-aggregable.
608 pub(crate) aggregable: bool,
609 // Basic bitcoin outpoint (txid, vout)
610 pub(crate) outpoint: BitcoinOutPoint,
611 // Following outpoint type, set of data needed to generate transaction digest
612 // and satisfy witness program.
613 pub(crate) witness_data: InputMaterial
616 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
617 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
618 #[derive(Clone, PartialEq)]
620 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
621 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
622 /// only win from it, so it's never an OnchainEvent
624 htlc_update: (HTLCSource, PaymentHash),
627 descriptor: SpendableOutputDescriptor,
631 const SERIALIZATION_VERSION: u8 = 1;
632 const MIN_SERIALIZATION_VERSION: u8 = 1;
634 #[cfg_attr(test, derive(PartialEq))]
636 pub(super) enum ChannelMonitorUpdateStep {
637 LatestLocalCommitmentTXInfo {
638 commitment_tx: LocalCommitmentTransaction,
639 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
641 LatestRemoteCommitmentTXInfo {
642 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
643 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
644 commitment_number: u64,
645 their_revocation_point: PublicKey,
648 payment_preimage: PaymentPreimage,
654 /// Used to indicate that the no future updates will occur, and likely that the latest local
655 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
657 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
658 /// think we've fallen behind!
659 should_broadcast: bool,
663 impl Writeable for ChannelMonitorUpdateStep {
664 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
666 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
668 commitment_tx.write(w)?;
669 (htlc_outputs.len() as u64).write(w)?;
670 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
676 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
678 unsigned_commitment_tx.write(w)?;
679 commitment_number.write(w)?;
680 their_revocation_point.write(w)?;
681 (htlc_outputs.len() as u64).write(w)?;
682 for &(ref output, ref source) in htlc_outputs.iter() {
684 source.as_ref().map(|b| b.as_ref()).write(w)?;
687 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
689 payment_preimage.write(w)?;
691 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
696 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
698 should_broadcast.write(w)?;
704 impl Readable for ChannelMonitorUpdateStep {
705 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
706 match Readable::read(r)? {
708 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
709 commitment_tx: Readable::read(r)?,
711 let len: u64 = Readable::read(r)?;
712 let mut res = Vec::new();
714 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
721 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
722 unsigned_commitment_tx: Readable::read(r)?,
723 commitment_number: Readable::read(r)?,
724 their_revocation_point: Readable::read(r)?,
726 let len: u64 = Readable::read(r)?;
727 let mut res = Vec::new();
729 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
736 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
737 payment_preimage: Readable::read(r)?,
741 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
742 idx: Readable::read(r)?,
743 secret: Readable::read(r)?,
747 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
748 should_broadcast: Readable::read(r)?
751 _ => Err(DecodeError::InvalidValue),
756 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
757 /// on-chain transactions to ensure no loss of funds occurs.
759 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
760 /// information and are actively monitoring the chain.
762 /// Pending Events or updated HTLCs which have not yet been read out by
763 /// get_and_clear_pending_htlcs_updated or get_and_clear_pending_events are serialized to disk and
764 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
765 /// gotten are fully handled before re-serializing the new state.
766 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
767 latest_update_id: u64,
768 commitment_transaction_number_obscure_factor: u64,
770 destination_script: Script,
771 broadcasted_local_revokable_script: Option<(Script, SecretKey, Script)>,
772 remote_payment_script: Script,
773 shutdown_script: Script,
776 funding_info: (OutPoint, Script),
777 current_remote_commitment_txid: Option<Txid>,
778 prev_remote_commitment_txid: Option<Txid>,
780 their_htlc_base_key: PublicKey,
781 their_delayed_payment_base_key: PublicKey,
782 funding_redeemscript: Script,
783 channel_value_satoshis: u64,
784 // first is the idx of the first of the two revocation points
785 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
787 our_to_self_delay: u16,
788 their_to_self_delay: u16,
790 commitment_secrets: CounterpartyCommitmentSecrets,
791 remote_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
792 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
793 /// Nor can we figure out their commitment numbers without the commitment transaction they are
794 /// spending. Thus, in order to claim them via revocation key, we track all the remote
795 /// commitment transactions which we find on-chain, mapping them to the commitment number which
796 /// can be used to derive the revocation key and claim the transactions.
797 remote_commitment_txn_on_chain: HashMap<Txid, (u64, Vec<Script>)>,
798 /// Cache used to make pruning of payment_preimages faster.
799 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
800 /// remote transactions (ie should remain pretty small).
801 /// Serialized to disk but should generally not be sent to Watchtowers.
802 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
804 // We store two local commitment transactions to avoid any race conditions where we may update
805 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
806 // various monitors for one channel being out of sync, and us broadcasting a local
807 // transaction for which we have deleted claim information on some watchtowers.
808 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
809 current_local_commitment_tx: LocalSignedTx,
811 // Used just for ChannelManager to make sure it has the latest channel data during
813 current_remote_commitment_number: u64,
814 // Used just for ChannelManager to make sure it has the latest channel data during
816 current_local_commitment_number: u64,
818 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
820 pending_htlcs_updated: Vec<HTLCUpdate>,
821 pending_events: Vec<events::Event>,
823 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
824 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
825 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
826 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
828 // If we get serialized out and re-read, we need to make sure that the chain monitoring
829 // interface knows about the TXOs that we want to be notified of spends of. We could probably
830 // be smart and derive them from the above storage fields, but its much simpler and more
831 // Obviously Correct (tm) if we just keep track of them explicitly.
832 outputs_to_watch: HashMap<Txid, Vec<Script>>,
835 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
837 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
839 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
840 // channel has been force-closed. After this is set, no further local commitment transaction
841 // updates may occur, and we panic!() if one is provided.
842 lockdown_from_offchain: bool,
844 // Set once we've signed a local commitment transaction and handed it over to our
845 // OnchainTxHandler. After this is set, no future updates to our local commitment transactions
846 // may occur, and we fail any such monitor updates.
847 local_tx_signed: bool,
849 // We simply modify last_block_hash in Channel's block_connected so that serialization is
850 // consistent but hopefully the users' copy handles block_connected in a consistent way.
851 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
852 // their last_block_hash from its state and not based on updated copies that didn't run through
853 // the full block_connected).
854 pub(crate) last_block_hash: BlockHash,
855 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
858 #[cfg(any(test, feature = "fuzztarget"))]
859 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
860 /// underlying object
861 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
862 fn eq(&self, other: &Self) -> bool {
863 if self.latest_update_id != other.latest_update_id ||
864 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
865 self.destination_script != other.destination_script ||
866 self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
867 self.remote_payment_script != other.remote_payment_script ||
868 self.keys.pubkeys() != other.keys.pubkeys() ||
869 self.funding_info != other.funding_info ||
870 self.current_remote_commitment_txid != other.current_remote_commitment_txid ||
871 self.prev_remote_commitment_txid != other.prev_remote_commitment_txid ||
872 self.their_htlc_base_key != other.their_htlc_base_key ||
873 self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
874 self.funding_redeemscript != other.funding_redeemscript ||
875 self.channel_value_satoshis != other.channel_value_satoshis ||
876 self.their_cur_revocation_points != other.their_cur_revocation_points ||
877 self.our_to_self_delay != other.our_to_self_delay ||
878 self.their_to_self_delay != other.their_to_self_delay ||
879 self.commitment_secrets != other.commitment_secrets ||
880 self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
881 self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
882 self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
883 self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
884 self.current_remote_commitment_number != other.current_remote_commitment_number ||
885 self.current_local_commitment_number != other.current_local_commitment_number ||
886 self.current_local_commitment_tx != other.current_local_commitment_tx ||
887 self.payment_preimages != other.payment_preimages ||
888 self.pending_htlcs_updated != other.pending_htlcs_updated ||
889 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
890 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
891 self.outputs_to_watch != other.outputs_to_watch ||
892 self.lockdown_from_offchain != other.lockdown_from_offchain ||
893 self.local_tx_signed != other.local_tx_signed
902 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
903 /// Writes this monitor into the given writer, suitable for writing to disk.
905 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
906 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
907 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
908 /// returned block hash and the the current chain and then reconnecting blocks to get to the
909 /// best chain) upon deserializing the object!
910 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
911 //TODO: We still write out all the serialization here manually instead of using the fancy
912 //serialization framework we have, we should migrate things over to it.
913 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
914 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
916 self.latest_update_id.write(writer)?;
918 // Set in initial Channel-object creation, so should always be set by now:
919 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
921 self.destination_script.write(writer)?;
922 if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
923 writer.write_all(&[0; 1])?;
924 broadcasted_local_revokable_script.0.write(writer)?;
925 broadcasted_local_revokable_script.1.write(writer)?;
926 broadcasted_local_revokable_script.2.write(writer)?;
928 writer.write_all(&[1; 1])?;
931 self.remote_payment_script.write(writer)?;
932 self.shutdown_script.write(writer)?;
934 self.keys.write(writer)?;
935 writer.write_all(&self.funding_info.0.txid[..])?;
936 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
937 self.funding_info.1.write(writer)?;
938 self.current_remote_commitment_txid.write(writer)?;
939 self.prev_remote_commitment_txid.write(writer)?;
941 writer.write_all(&self.their_htlc_base_key.serialize())?;
942 writer.write_all(&self.their_delayed_payment_base_key.serialize())?;
943 self.funding_redeemscript.write(writer)?;
944 self.channel_value_satoshis.write(writer)?;
946 match self.their_cur_revocation_points {
947 Some((idx, pubkey, second_option)) => {
948 writer.write_all(&byte_utils::be48_to_array(idx))?;
949 writer.write_all(&pubkey.serialize())?;
950 match second_option {
951 Some(second_pubkey) => {
952 writer.write_all(&second_pubkey.serialize())?;
955 writer.write_all(&[0; 33])?;
960 writer.write_all(&byte_utils::be48_to_array(0))?;
964 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
965 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay))?;
967 self.commitment_secrets.write(writer)?;
969 macro_rules! serialize_htlc_in_commitment {
970 ($htlc_output: expr) => {
971 writer.write_all(&[$htlc_output.offered as u8; 1])?;
972 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
973 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
974 writer.write_all(&$htlc_output.payment_hash.0[..])?;
975 $htlc_output.transaction_output_index.write(writer)?;
979 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
980 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
981 writer.write_all(&txid[..])?;
982 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
983 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
984 serialize_htlc_in_commitment!(htlc_output);
985 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
989 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
990 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
991 writer.write_all(&txid[..])?;
992 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
993 (txouts.len() as u64).write(writer)?;
994 for script in txouts.iter() {
995 script.write(writer)?;
999 writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
1000 for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
1001 writer.write_all(&payment_hash.0[..])?;
1002 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1005 macro_rules! serialize_local_tx {
1006 ($local_tx: expr) => {
1007 $local_tx.txid.write(writer)?;
1008 writer.write_all(&$local_tx.revocation_key.serialize())?;
1009 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
1010 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
1011 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
1012 writer.write_all(&$local_tx.per_commitment_point.serialize())?;
1014 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
1015 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
1016 for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
1017 serialize_htlc_in_commitment!(htlc_output);
1018 if let &Some(ref their_sig) = sig {
1020 writer.write_all(&their_sig.serialize_compact())?;
1024 htlc_source.write(writer)?;
1029 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
1030 writer.write_all(&[1; 1])?;
1031 serialize_local_tx!(prev_local_tx);
1033 writer.write_all(&[0; 1])?;
1036 serialize_local_tx!(self.current_local_commitment_tx);
1038 writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
1039 writer.write_all(&byte_utils::be48_to_array(self.current_local_commitment_number))?;
1041 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1042 for payment_preimage in self.payment_preimages.values() {
1043 writer.write_all(&payment_preimage.0[..])?;
1046 writer.write_all(&byte_utils::be64_to_array(self.pending_htlcs_updated.len() as u64))?;
1047 for data in self.pending_htlcs_updated.iter() {
1048 data.write(writer)?;
1051 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1052 for event in self.pending_events.iter() {
1053 event.write(writer)?;
1056 self.last_block_hash.write(writer)?;
1058 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1059 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1060 writer.write_all(&byte_utils::be32_to_array(**target))?;
1061 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1062 for ev in events.iter() {
1064 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1066 htlc_update.0.write(writer)?;
1067 htlc_update.1.write(writer)?;
1069 OnchainEvent::MaturingOutput { ref descriptor } => {
1071 descriptor.write(writer)?;
1077 (self.outputs_to_watch.len() as u64).write(writer)?;
1078 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1079 txid.write(writer)?;
1080 (output_scripts.len() as u64).write(writer)?;
1081 for script in output_scripts.iter() {
1082 script.write(writer)?;
1085 self.onchain_tx_handler.write(writer)?;
1087 self.lockdown_from_offchain.write(writer)?;
1088 self.local_tx_signed.write(writer)?;
1094 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1095 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1096 our_to_self_delay: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1097 their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey,
1098 their_to_self_delay: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1099 commitment_transaction_number_obscure_factor: u64,
1100 initial_local_commitment_tx: LocalCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
1102 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1103 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
1104 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1105 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1106 let remote_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1108 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), their_to_self_delay);
1110 let local_tx_sequence = initial_local_commitment_tx.unsigned_tx.input[0].sequence as u64;
1111 let local_tx_locktime = initial_local_commitment_tx.unsigned_tx.lock_time as u64;
1112 let local_commitment_tx = LocalSignedTx {
1113 txid: initial_local_commitment_tx.txid(),
1114 revocation_key: initial_local_commitment_tx.local_keys.revocation_key,
1115 a_htlc_key: initial_local_commitment_tx.local_keys.a_htlc_key,
1116 b_htlc_key: initial_local_commitment_tx.local_keys.b_htlc_key,
1117 delayed_payment_key: initial_local_commitment_tx.local_keys.a_delayed_payment_key,
1118 per_commitment_point: initial_local_commitment_tx.local_keys.per_commitment_point,
1119 feerate_per_kw: initial_local_commitment_tx.feerate_per_kw,
1120 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1122 // Returning a monitor error before updating tracking points means in case of using
1123 // a concurrent watchtower implementation for same channel, if this one doesn't
1124 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1125 // for which you want to spend outputs. We're NOT robust again this scenario right
1126 // now but we should consider it later.
1127 onchain_tx_handler.provide_latest_local_tx(initial_local_commitment_tx).unwrap();
1130 latest_update_id: 0,
1131 commitment_transaction_number_obscure_factor,
1133 destination_script: destination_script.clone(),
1134 broadcasted_local_revokable_script: None,
1135 remote_payment_script,
1140 current_remote_commitment_txid: None,
1141 prev_remote_commitment_txid: None,
1143 their_htlc_base_key: their_htlc_base_key.clone(),
1144 their_delayed_payment_base_key: their_delayed_payment_base_key.clone(),
1145 funding_redeemscript,
1146 channel_value_satoshis: channel_value_satoshis,
1147 their_cur_revocation_points: None,
1150 their_to_self_delay,
1152 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1153 remote_claimable_outpoints: HashMap::new(),
1154 remote_commitment_txn_on_chain: HashMap::new(),
1155 remote_hash_commitment_number: HashMap::new(),
1157 prev_local_signed_commitment_tx: None,
1158 current_local_commitment_tx: local_commitment_tx,
1159 current_remote_commitment_number: 1 << 48,
1160 current_local_commitment_number: 0xffff_ffff_ffff - ((((local_tx_sequence & 0xffffff) << 3*8) | (local_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1162 payment_preimages: HashMap::new(),
1163 pending_htlcs_updated: Vec::new(),
1164 pending_events: Vec::new(),
1166 onchain_events_waiting_threshold_conf: HashMap::new(),
1167 outputs_to_watch: HashMap::new(),
1171 lockdown_from_offchain: false,
1172 local_tx_signed: false,
1174 last_block_hash: Default::default(),
1175 secp_ctx: Secp256k1::new(),
1179 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1180 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1181 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1182 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1183 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1184 return Err(MonitorUpdateError("Previous secret did not match new one"));
1187 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1188 // events for now-revoked/fulfilled HTLCs.
1189 if let Some(txid) = self.prev_remote_commitment_txid.take() {
1190 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1195 if !self.payment_preimages.is_empty() {
1196 let cur_local_signed_commitment_tx = &self.current_local_commitment_tx;
1197 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1198 let min_idx = self.get_min_seen_secret();
1199 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1201 self.payment_preimages.retain(|&k, _| {
1202 for &(ref htlc, _, _) in cur_local_signed_commitment_tx.htlc_outputs.iter() {
1203 if k == htlc.payment_hash {
1207 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1208 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1209 if k == htlc.payment_hash {
1214 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1221 remote_hash_commitment_number.remove(&k);
1230 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1231 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1232 /// possibly future revocation/preimage information) to claim outputs where possible.
1233 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1234 pub(super) fn provide_latest_remote_commitment_tx_info<L: Deref>(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1235 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1236 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1237 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1239 for &(ref htlc, _) in &htlc_outputs {
1240 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1243 let new_txid = unsigned_commitment_tx.txid();
1244 log_trace!(logger, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1245 log_trace!(logger, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1246 self.prev_remote_commitment_txid = self.current_remote_commitment_txid.take();
1247 self.current_remote_commitment_txid = Some(new_txid);
1248 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
1249 self.current_remote_commitment_number = commitment_number;
1250 //TODO: Merge this into the other per-remote-transaction output storage stuff
1251 match self.their_cur_revocation_points {
1252 Some(old_points) => {
1253 if old_points.0 == commitment_number + 1 {
1254 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1255 } else if old_points.0 == commitment_number + 2 {
1256 if let Some(old_second_point) = old_points.2 {
1257 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1259 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1262 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1266 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1271 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1272 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1273 /// is important that any clones of this channel monitor (including remote clones) by kept
1274 /// up-to-date as our local commitment transaction is updated.
1275 /// Panics if set_their_to_self_delay has never been called.
1276 pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1277 if self.local_tx_signed {
1278 return Err(MonitorUpdateError("A local commitment tx has already been signed, no new local commitment txn can be sent to our counterparty"));
1280 let txid = commitment_tx.txid();
1281 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1282 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1283 let mut new_local_commitment_tx = LocalSignedTx {
1285 revocation_key: commitment_tx.local_keys.revocation_key,
1286 a_htlc_key: commitment_tx.local_keys.a_htlc_key,
1287 b_htlc_key: commitment_tx.local_keys.b_htlc_key,
1288 delayed_payment_key: commitment_tx.local_keys.a_delayed_payment_key,
1289 per_commitment_point: commitment_tx.local_keys.per_commitment_point,
1290 feerate_per_kw: commitment_tx.feerate_per_kw,
1291 htlc_outputs: htlc_outputs,
1293 // Returning a monitor error before updating tracking points means in case of using
1294 // a concurrent watchtower implementation for same channel, if this one doesn't
1295 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1296 // for which you want to spend outputs. We're NOT robust again this scenario right
1297 // now but we should consider it later.
1298 if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx) {
1299 return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1301 self.current_local_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1302 mem::swap(&mut new_local_commitment_tx, &mut self.current_local_commitment_tx);
1303 self.prev_local_signed_commitment_tx = Some(new_local_commitment_tx);
1307 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1308 /// commitment_tx_infos which contain the payment hash have been revoked.
1309 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1310 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1313 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1314 where B::Target: BroadcasterInterface,
1317 for tx in self.get_latest_local_commitment_txn(logger).iter() {
1318 broadcaster.broadcast_transaction(tx);
1322 /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
1323 pub(super) fn update_monitor_ooo<L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, logger: &L) -> Result<(), MonitorUpdateError> where L::Target: Logger {
1324 for update in updates.updates.drain(..) {
1326 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1327 if self.lockdown_from_offchain { panic!(); }
1328 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1330 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1331 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1332 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1333 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1334 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1335 self.provide_secret(idx, secret)?,
1336 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
1339 self.latest_update_id = updates.update_id;
1343 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1346 /// panics if the given update is not the next update by update_id.
1347 pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
1348 where B::Target: BroadcasterInterface,
1351 if self.latest_update_id + 1 != updates.update_id {
1352 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1354 for update in updates.updates.drain(..) {
1356 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1357 if self.lockdown_from_offchain { panic!(); }
1358 self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
1360 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1361 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
1362 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1363 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1364 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1365 self.provide_secret(idx, secret)?,
1366 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1367 self.lockdown_from_offchain = true;
1368 if should_broadcast {
1369 self.broadcast_latest_local_commitment_txn(broadcaster, logger);
1371 log_error!(logger, "You have a toxic local commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_local_commitment_txn to be informed of manual action to take");
1376 self.latest_update_id = updates.update_id;
1380 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1382 pub fn get_latest_update_id(&self) -> u64 {
1383 self.latest_update_id
1386 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1387 pub fn get_funding_txo(&self) -> OutPoint {
1391 /// Gets a list of txids, with their output scripts (in the order they appear in the
1392 /// transaction), which we must learn about spends of via block_connected().
1393 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<Script>> {
1394 &self.outputs_to_watch
1397 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1398 /// Generally useful when deserializing as during normal operation the return values of
1399 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1400 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1401 pub fn get_monitored_outpoints(&self) -> Vec<(Txid, u32, &Script)> {
1402 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1403 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1404 for (idx, output) in outputs.iter().enumerate() {
1405 res.push(((*txid).clone(), idx as u32, output));
1411 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1412 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_htlcs_updated().
1413 pub fn get_and_clear_pending_htlcs_updated(&mut self) -> Vec<HTLCUpdate> {
1414 let mut ret = Vec::new();
1415 mem::swap(&mut ret, &mut self.pending_htlcs_updated);
1419 /// Gets the list of pending events which were generated by previous actions, clearing the list
1422 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1423 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1424 /// no internal locking in ChannelMonitors.
1425 pub fn get_and_clear_pending_events(&mut self) -> Vec<events::Event> {
1426 let mut ret = Vec::new();
1427 mem::swap(&mut ret, &mut self.pending_events);
1431 /// Can only fail if idx is < get_min_seen_secret
1432 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1433 self.commitment_secrets.get_secret(idx)
1436 pub(super) fn get_min_seen_secret(&self) -> u64 {
1437 self.commitment_secrets.get_min_seen_secret()
1440 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1441 self.current_remote_commitment_number
1444 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1445 self.current_local_commitment_number
1448 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1449 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1450 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1451 /// HTLC-Success/HTLC-Timeout transactions.
1452 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1453 /// revoked remote commitment tx
1454 fn check_spend_remote_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1455 // Most secp and related errors trying to create keys means we have no hope of constructing
1456 // a spend transaction...so we return no transactions to broadcast
1457 let mut claimable_outpoints = Vec::new();
1458 let mut watch_outputs = Vec::new();
1460 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1461 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1463 macro_rules! ignore_error {
1464 ( $thing : expr ) => {
1467 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1472 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);
1473 if commitment_number >= self.get_min_seen_secret() {
1474 let secret = self.get_secret(commitment_number).unwrap();
1475 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1476 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1477 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1478 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
1479 let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().htlc_basepoint));
1480 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key));
1481 let a_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_htlc_base_key));
1483 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1484 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1486 // First, process non-htlc outputs (to_local & to_remote)
1487 for (idx, outp) in tx.output.iter().enumerate() {
1488 if outp.script_pubkey == revokeable_p2wsh {
1489 let witness_data = InputMaterial::Revoked { witness_script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: outp.value };
1490 claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
1494 // Then, try to find revoked htlc outputs
1495 if let Some(ref per_commitment_data) = per_commitment_option {
1496 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1497 if let Some(transaction_output_index) = htlc.transaction_output_index {
1498 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1499 if transaction_output_index as usize >= tx.output.len() ||
1500 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1501 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1502 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1504 let witness_data = InputMaterial::Revoked { witness_script: expected_script, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: true, amount: tx.output[transaction_output_index as usize].value };
1505 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1510 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1511 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1512 // We're definitely a remote commitment transaction!
1513 log_trace!(logger, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1514 watch_outputs.append(&mut tx.output.clone());
1515 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1517 macro_rules! check_htlc_fails {
1518 ($txid: expr, $commitment_tx: expr) => {
1519 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1520 for &(ref htlc, ref source_option) in outpoints.iter() {
1521 if let &Some(ref source) = source_option {
1522 log_info!(logger, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1523 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1524 hash_map::Entry::Occupied(mut entry) => {
1525 let e = entry.get_mut();
1526 e.retain(|ref event| {
1528 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1529 return htlc_update.0 != **source
1534 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1536 hash_map::Entry::Vacant(entry) => {
1537 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1545 if let Some(ref txid) = self.current_remote_commitment_txid {
1546 check_htlc_fails!(txid, "current");
1548 if let Some(ref txid) = self.prev_remote_commitment_txid {
1549 check_htlc_fails!(txid, "remote");
1551 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1553 } else if let Some(per_commitment_data) = per_commitment_option {
1554 // While this isn't useful yet, there is a potential race where if a counterparty
1555 // revokes a state at the same time as the commitment transaction for that state is
1556 // confirmed, and the watchtower receives the block before the user, the user could
1557 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1558 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1559 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1561 watch_outputs.append(&mut tx.output.clone());
1562 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1564 log_trace!(logger, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1566 macro_rules! check_htlc_fails {
1567 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1568 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1569 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1570 if let &Some(ref source) = source_option {
1571 // Check if the HTLC is present in the commitment transaction that was
1572 // broadcast, but not if it was below the dust limit, which we should
1573 // fail backwards immediately as there is no way for us to learn the
1574 // payment_preimage.
1575 // Note that if the dust limit were allowed to change between
1576 // commitment transactions we'd want to be check whether *any*
1577 // broadcastable commitment transaction has the HTLC in it, but it
1578 // cannot currently change after channel initialization, so we don't
1580 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1581 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1585 log_trace!(logger, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1586 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1587 hash_map::Entry::Occupied(mut entry) => {
1588 let e = entry.get_mut();
1589 e.retain(|ref event| {
1591 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1592 return htlc_update.0 != **source
1597 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1599 hash_map::Entry::Vacant(entry) => {
1600 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1608 if let Some(ref txid) = self.current_remote_commitment_txid {
1609 check_htlc_fails!(txid, "current", 'current_loop);
1611 if let Some(ref txid) = self.prev_remote_commitment_txid {
1612 check_htlc_fails!(txid, "previous", 'prev_loop);
1615 if let Some(revocation_points) = self.their_cur_revocation_points {
1616 let revocation_point_option =
1617 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1618 else if let Some(point) = revocation_points.2.as_ref() {
1619 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1621 if let Some(revocation_point) = revocation_point_option {
1622 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().revocation_basepoint));
1623 let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().htlc_basepoint));
1624 let htlc_privkey = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.keys.htlc_base_key()));
1625 let a_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.their_htlc_base_key));
1627 // Then, try to find htlc outputs
1628 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1629 if let Some(transaction_output_index) = htlc.transaction_output_index {
1630 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1631 if transaction_output_index as usize >= tx.output.len() ||
1632 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1633 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1634 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1636 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1637 let aggregable = if !htlc.offered { false } else { true };
1638 if preimage.is_some() || !htlc.offered {
1639 let witness_data = InputMaterial::RemoteHTLC { witness_script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry };
1640 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1647 (claimable_outpoints, (commitment_txid, watch_outputs))
1650 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1651 fn check_spend_remote_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<TxOut>)>) where L::Target: Logger {
1652 let htlc_txid = tx.txid();
1653 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1654 return (Vec::new(), None)
1657 macro_rules! ignore_error {
1658 ( $thing : expr ) => {
1661 Err(_) => return (Vec::new(), None)
1666 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1667 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1668 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1669 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1670 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
1671 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.their_delayed_payment_base_key));
1672 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1674 log_trace!(logger, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1675 let witness_data = InputMaterial::Revoked { witness_script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: tx.output[0].value };
1676 let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.our_to_self_delay as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
1677 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1680 fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<ClaimRequest>, Vec<TxOut>, Option<(Script, SecretKey, Script)>) {
1681 let mut claim_requests = Vec::with_capacity(local_tx.htlc_outputs.len());
1682 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1684 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay, &local_tx.delayed_payment_key);
1685 let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, self.keys.delayed_payment_base_key()) {
1686 Some((redeemscript.to_v0_p2wsh(), local_delayedkey, redeemscript))
1689 for &(ref htlc, _, _) in local_tx.htlc_outputs.iter() {
1690 if let Some(transaction_output_index) = htlc.transaction_output_index {
1691 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: local_tx.txid, vout: transaction_output_index as u32 },
1692 witness_data: InputMaterial::LocalHTLC {
1693 preimage: if !htlc.offered {
1694 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1695 Some(preimage.clone())
1697 // We can't build an HTLC-Success transaction without the preimage
1701 amount: htlc.amount_msat,
1703 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1707 (claim_requests, watch_outputs, broadcasted_local_revokable_script)
1710 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1711 /// revoked using data in local_claimable_outpoints.
1712 /// Should not be used if check_spend_revoked_transaction succeeds.
1713 fn check_spend_local_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<TxOut>)) where L::Target: Logger {
1714 let commitment_txid = tx.txid();
1715 let mut claim_requests = Vec::new();
1716 let mut watch_outputs = Vec::new();
1718 macro_rules! wait_threshold_conf {
1719 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1720 log_trace!(logger, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1721 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1722 hash_map::Entry::Occupied(mut entry) => {
1723 let e = entry.get_mut();
1724 e.retain(|ref event| {
1726 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1727 return htlc_update.0 != $source
1732 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1734 hash_map::Entry::Vacant(entry) => {
1735 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1741 macro_rules! append_onchain_update {
1742 ($updates: expr) => {
1743 claim_requests = $updates.0;
1744 watch_outputs.append(&mut $updates.1);
1745 self.broadcasted_local_revokable_script = $updates.2;
1749 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1750 let mut is_local_tx = false;
1752 if self.current_local_commitment_tx.txid == commitment_txid {
1754 log_trace!(logger, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1755 let mut res = self.broadcast_by_local_state(tx, &self.current_local_commitment_tx);
1756 append_onchain_update!(res);
1757 } else if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1758 if local_tx.txid == commitment_txid {
1760 log_trace!(logger, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1761 let mut res = self.broadcast_by_local_state(tx, local_tx);
1762 append_onchain_update!(res);
1766 macro_rules! fail_dust_htlcs_after_threshold_conf {
1767 ($local_tx: expr) => {
1768 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1769 if htlc.transaction_output_index.is_none() {
1770 if let &Some(ref source) = source {
1771 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1779 fail_dust_htlcs_after_threshold_conf!(self.current_local_commitment_tx);
1780 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1781 fail_dust_htlcs_after_threshold_conf!(local_tx);
1785 (claim_requests, (commitment_txid, watch_outputs))
1788 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1789 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1790 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1791 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1792 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1793 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1794 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1795 /// out-of-band the other node operator to coordinate with him if option is available to you.
1796 /// In any-case, choice is up to the user.
1797 pub fn get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1798 log_trace!(logger, "Getting signed latest local commitment transaction!");
1799 self.local_tx_signed = true;
1800 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1801 let txid = commitment_tx.txid();
1802 let mut res = vec![commitment_tx];
1803 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1804 if let Some(vout) = htlc.0.transaction_output_index {
1805 let preimage = if !htlc.0.offered {
1806 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1807 // We can't build an HTLC-Success transaction without the preimage
1811 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1812 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1817 // 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.
1818 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1824 /// Unsafe test-only version of get_latest_local_commitment_txn used by our test framework
1825 /// to bypass LocalCommitmentTransaction state update lockdown after signature and generate
1826 /// revoked commitment transaction.
1828 pub fn unsafe_get_latest_local_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1829 log_trace!(logger, "Getting signed copy of latest local commitment transaction!");
1830 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_local_tx(&self.funding_redeemscript) {
1831 let txid = commitment_tx.txid();
1832 let mut res = vec![commitment_tx];
1833 for htlc in self.current_local_commitment_tx.htlc_outputs.iter() {
1834 if let Some(vout) = htlc.0.transaction_output_index {
1835 let preimage = if !htlc.0.offered {
1836 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1837 // We can't build an HTLC-Success transaction without the preimage
1841 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1842 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1852 /// Called when a new block has been connected to the best chain by <SimpleManyChannelMonitor
1853 /// as ChainListener>::block_connected, and should thus generally not be called during normal
1854 /// operation. It is exposed both for users who wish to use ChannelMonitors directly and to
1855 /// simplify rescans that occur at load-time.
1857 /// This is very similar to ChainListener::block_connected itself, but requires an &mut self,
1858 /// and an explicit reference to a transaction broadcaster and fee estimator.
1860 /// Returns a list of new (txid, outputs) pairs which spends of must be watched for. Note that
1861 /// after this call these are also available via get_outputs_to_watch().
1862 pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<TxOut>)>
1863 where B::Target: BroadcasterInterface,
1864 F::Target: FeeEstimator,
1867 for tx in txn_matched {
1868 let mut output_val = 0;
1869 for out in tx.output.iter() {
1870 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1871 output_val += out.value;
1872 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1876 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1877 let mut watch_outputs = Vec::new();
1878 let mut claimable_outpoints = Vec::new();
1879 for tx in txn_matched {
1880 if tx.input.len() == 1 {
1881 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1882 // commitment transactions and HTLC transactions will all only ever have one input,
1883 // which is an easy way to filter out any potential non-matching txn for lazy
1885 let prevout = &tx.input[0].previous_output;
1886 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1887 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1888 let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height, &logger);
1889 if !new_outputs.1.is_empty() {
1890 watch_outputs.push(new_outputs);
1892 if new_outpoints.is_empty() {
1893 let (mut new_outpoints, new_outputs) = self.check_spend_local_transaction(&tx, height, &logger);
1894 if !new_outputs.1.is_empty() {
1895 watch_outputs.push(new_outputs);
1897 claimable_outpoints.append(&mut new_outpoints);
1899 claimable_outpoints.append(&mut new_outpoints);
1902 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1903 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height, &logger);
1904 claimable_outpoints.append(&mut new_outpoints);
1905 if let Some(new_outputs) = new_outputs_option {
1906 watch_outputs.push(new_outputs);
1911 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1912 // can also be resolved in a few other ways which can have more than one output. Thus,
1913 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1914 self.is_resolving_htlc_output(&tx, height, &logger);
1916 self.is_paying_spendable_output(&tx, height, &logger);
1918 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1919 if should_broadcast {
1920 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() }});
1922 if should_broadcast {
1923 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(&self.funding_redeemscript) {
1924 let (mut new_outpoints, new_outputs, _) = self.broadcast_by_local_state(&commitment_tx, &self.current_local_commitment_tx);
1925 if !new_outputs.is_empty() {
1926 watch_outputs.push((self.current_local_commitment_tx.txid.clone(), new_outputs));
1928 claimable_outpoints.append(&mut new_outpoints);
1931 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1934 OnchainEvent::HTLCUpdate { htlc_update } => {
1935 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1936 self.pending_htlcs_updated.push(HTLCUpdate {
1937 payment_hash: htlc_update.1,
1938 payment_preimage: None,
1939 source: htlc_update.0,
1942 OnchainEvent::MaturingOutput { descriptor } => {
1943 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1944 self.pending_events.push(events::Event::SpendableOutputs {
1945 outputs: vec![descriptor]
1951 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1953 self.last_block_hash = block_hash.clone();
1954 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1955 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1961 /// Called when a block has been disconnected from the best chain by <SimpleManyChannelMonitor
1962 /// as ChainListener>::block_disconnected, and should thus generally not be called during
1963 /// normal operation. It is exposed both for users who wish to use ChannelMonitors directly and
1964 /// to simplify rescans that occur at load-time.
1966 /// This is very similar to ChainListener::block_disconnected itself, but requires an &mut self,
1967 /// and an explicit reference to a transaction broadcaster and fee estimator.
1968 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, block_hash: &BlockHash, broadcaster: B, fee_estimator: F, logger: L)
1969 where B::Target: BroadcasterInterface,
1970 F::Target: FeeEstimator,
1973 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1974 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1976 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1977 //- maturing spendable output has transaction paying us has been disconnected
1980 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1982 self.last_block_hash = block_hash.clone();
1985 pub(super) fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
1986 // We need to consider all HTLCs which are:
1987 // * in any unrevoked remote commitment transaction, as they could broadcast said
1988 // transactions and we'd end up in a race, or
1989 // * are in our latest local commitment transaction, as this is the thing we will
1990 // broadcast if we go on-chain.
1991 // Note that we consider HTLCs which were below dust threshold here - while they don't
1992 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1993 // to the source, and if we don't fail the channel we will have to ensure that the next
1994 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1995 // easier to just fail the channel as this case should be rare enough anyway.
1996 macro_rules! scan_commitment {
1997 ($htlcs: expr, $local_tx: expr) => {
1998 for ref htlc in $htlcs {
1999 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2000 // chain with enough room to claim the HTLC without our counterparty being able to
2001 // time out the HTLC first.
2002 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2003 // concern is being able to claim the corresponding inbound HTLC (on another
2004 // channel) before it expires. In fact, we don't even really care if our
2005 // counterparty here claims such an outbound HTLC after it expired as long as we
2006 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2007 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2008 // we give ourselves a few blocks of headroom after expiration before going
2009 // on-chain for an expired HTLC.
2010 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2011 // from us until we've reached the point where we go on-chain with the
2012 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2013 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2014 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2015 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2016 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2017 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2018 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2019 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2020 // The final, above, condition is checked for statically in channelmanager
2021 // with CHECK_CLTV_EXPIRY_SANITY_2.
2022 let htlc_outbound = $local_tx == htlc.offered;
2023 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2024 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2025 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2032 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2034 if let Some(ref txid) = self.current_remote_commitment_txid {
2035 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2036 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2039 if let Some(ref txid) = self.prev_remote_commitment_txid {
2040 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2041 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2048 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2049 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2050 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2051 'outer_loop: for input in &tx.input {
2052 let mut payment_data = None;
2053 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2054 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2055 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2056 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2058 macro_rules! log_claim {
2059 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2060 // We found the output in question, but aren't failing it backwards
2061 // as we have no corresponding source and no valid remote commitment txid
2062 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2063 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2064 let outbound_htlc = $local_tx == $htlc.offered;
2065 if ($local_tx && revocation_sig_claim) ||
2066 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2067 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2068 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2069 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2070 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2072 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2073 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2074 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2075 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2080 macro_rules! check_htlc_valid_remote {
2081 ($remote_txid: expr, $htlc_output: expr) => {
2082 if let Some(txid) = $remote_txid {
2083 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2084 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2085 if let &Some(ref source) = pending_source {
2086 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2087 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2096 macro_rules! scan_commitment {
2097 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2098 for (ref htlc_output, source_option) in $htlcs {
2099 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2100 if let Some(ref source) = source_option {
2101 log_claim!($tx_info, $local_tx, htlc_output, true);
2102 // We have a resolution of an HTLC either from one of our latest
2103 // local commitment transactions or an unrevoked remote commitment
2104 // transaction. This implies we either learned a preimage, the HTLC
2105 // has timed out, or we screwed up. In any case, we should now
2106 // resolve the source HTLC with the original sender.
2107 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2108 } else if !$local_tx {
2109 check_htlc_valid_remote!(self.current_remote_commitment_txid, htlc_output);
2110 if payment_data.is_none() {
2111 check_htlc_valid_remote!(self.prev_remote_commitment_txid, htlc_output);
2114 if payment_data.is_none() {
2115 log_claim!($tx_info, $local_tx, htlc_output, false);
2116 continue 'outer_loop;
2123 if input.previous_output.txid == self.current_local_commitment_tx.txid {
2124 scan_commitment!(self.current_local_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2125 "our latest local commitment tx", true);
2127 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2128 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2129 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2130 "our previous local commitment tx", true);
2133 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2134 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2135 "remote commitment tx", false);
2138 // Check that scan_commitment, above, decided there is some source worth relaying an
2139 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2140 if let Some((source, payment_hash)) = payment_data {
2141 let mut payment_preimage = PaymentPreimage([0; 32]);
2142 if accepted_preimage_claim {
2143 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2144 payment_preimage.0.copy_from_slice(&input.witness[3]);
2145 self.pending_htlcs_updated.push(HTLCUpdate {
2147 payment_preimage: Some(payment_preimage),
2151 } else if offered_preimage_claim {
2152 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2153 payment_preimage.0.copy_from_slice(&input.witness[1]);
2154 self.pending_htlcs_updated.push(HTLCUpdate {
2156 payment_preimage: Some(payment_preimage),
2161 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);
2162 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2163 hash_map::Entry::Occupied(mut entry) => {
2164 let e = entry.get_mut();
2165 e.retain(|ref event| {
2167 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2168 return htlc_update.0 != source
2173 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2175 hash_map::Entry::Vacant(entry) => {
2176 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2184 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2185 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2186 let mut spendable_output = None;
2187 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2188 if outp.script_pubkey == self.destination_script {
2189 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2190 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2191 output: outp.clone(),
2194 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2195 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2196 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2197 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2198 key: broadcasted_local_revokable_script.1,
2199 witness_script: broadcasted_local_revokable_script.2.clone(),
2200 to_self_delay: self.their_to_self_delay,
2201 output: outp.clone(),
2205 } else if self.remote_payment_script == outp.script_pubkey {
2206 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WPKH {
2207 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2208 key: self.keys.payment_key().clone(),
2209 output: outp.clone(),
2212 } else if outp.script_pubkey == self.shutdown_script {
2213 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2214 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2215 output: outp.clone(),
2219 if let Some(spendable_output) = spendable_output {
2220 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2221 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2222 hash_map::Entry::Occupied(mut entry) => {
2223 let e = entry.get_mut();
2224 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2226 hash_map::Entry::Vacant(entry) => {
2227 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2234 const MAX_ALLOC_SIZE: usize = 64*1024;
2236 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2237 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2238 macro_rules! unwrap_obj {
2242 Err(_) => return Err(DecodeError::InvalidValue),
2247 let _ver: u8 = Readable::read(reader)?;
2248 let min_ver: u8 = Readable::read(reader)?;
2249 if min_ver > SERIALIZATION_VERSION {
2250 return Err(DecodeError::UnknownVersion);
2253 let latest_update_id: u64 = Readable::read(reader)?;
2254 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2256 let destination_script = Readable::read(reader)?;
2257 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2259 let revokable_address = Readable::read(reader)?;
2260 let local_delayedkey = Readable::read(reader)?;
2261 let revokable_script = Readable::read(reader)?;
2262 Some((revokable_address, local_delayedkey, revokable_script))
2265 _ => return Err(DecodeError::InvalidValue),
2267 let remote_payment_script = Readable::read(reader)?;
2268 let shutdown_script = Readable::read(reader)?;
2270 let keys = Readable::read(reader)?;
2271 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2272 // barely-init'd ChannelMonitors that we can't do anything with.
2273 let outpoint = OutPoint {
2274 txid: Readable::read(reader)?,
2275 index: Readable::read(reader)?,
2277 let funding_info = (outpoint, Readable::read(reader)?);
2278 let current_remote_commitment_txid = Readable::read(reader)?;
2279 let prev_remote_commitment_txid = Readable::read(reader)?;
2281 let their_htlc_base_key = Readable::read(reader)?;
2282 let their_delayed_payment_base_key = Readable::read(reader)?;
2283 let funding_redeemscript = Readable::read(reader)?;
2284 let channel_value_satoshis = Readable::read(reader)?;
2286 let their_cur_revocation_points = {
2287 let first_idx = <U48 as Readable>::read(reader)?.0;
2291 let first_point = Readable::read(reader)?;
2292 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2293 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2294 Some((first_idx, first_point, None))
2296 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2301 let our_to_self_delay: u16 = Readable::read(reader)?;
2302 let their_to_self_delay: u16 = Readable::read(reader)?;
2304 let commitment_secrets = Readable::read(reader)?;
2306 macro_rules! read_htlc_in_commitment {
2309 let offered: bool = Readable::read(reader)?;
2310 let amount_msat: u64 = Readable::read(reader)?;
2311 let cltv_expiry: u32 = Readable::read(reader)?;
2312 let payment_hash: PaymentHash = Readable::read(reader)?;
2313 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2315 HTLCOutputInCommitment {
2316 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2322 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2323 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2324 for _ in 0..remote_claimable_outpoints_len {
2325 let txid: Txid = Readable::read(reader)?;
2326 let htlcs_count: u64 = Readable::read(reader)?;
2327 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2328 for _ in 0..htlcs_count {
2329 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2331 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2332 return Err(DecodeError::InvalidValue);
2336 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2337 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2338 for _ in 0..remote_commitment_txn_on_chain_len {
2339 let txid: Txid = Readable::read(reader)?;
2340 let commitment_number = <U48 as Readable>::read(reader)?.0;
2341 let outputs_count = <u64 as Readable>::read(reader)?;
2342 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2343 for _ in 0..outputs_count {
2344 outputs.push(Readable::read(reader)?);
2346 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2347 return Err(DecodeError::InvalidValue);
2351 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2352 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2353 for _ in 0..remote_hash_commitment_number_len {
2354 let payment_hash: PaymentHash = Readable::read(reader)?;
2355 let commitment_number = <U48 as Readable>::read(reader)?.0;
2356 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2357 return Err(DecodeError::InvalidValue);
2361 macro_rules! read_local_tx {
2364 let txid = Readable::read(reader)?;
2365 let revocation_key = Readable::read(reader)?;
2366 let a_htlc_key = Readable::read(reader)?;
2367 let b_htlc_key = Readable::read(reader)?;
2368 let delayed_payment_key = Readable::read(reader)?;
2369 let per_commitment_point = Readable::read(reader)?;
2370 let feerate_per_kw: u64 = Readable::read(reader)?;
2372 let htlcs_len: u64 = Readable::read(reader)?;
2373 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2374 for _ in 0..htlcs_len {
2375 let htlc = read_htlc_in_commitment!();
2376 let sigs = match <u8 as Readable>::read(reader)? {
2378 1 => Some(Readable::read(reader)?),
2379 _ => return Err(DecodeError::InvalidValue),
2381 htlcs.push((htlc, sigs, Readable::read(reader)?));
2386 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2393 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2396 Some(read_local_tx!())
2398 _ => return Err(DecodeError::InvalidValue),
2400 let current_local_commitment_tx = read_local_tx!();
2402 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2403 let current_local_commitment_number = <U48 as Readable>::read(reader)?.0;
2405 let payment_preimages_len: u64 = Readable::read(reader)?;
2406 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2407 for _ in 0..payment_preimages_len {
2408 let preimage: PaymentPreimage = Readable::read(reader)?;
2409 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2410 if let Some(_) = payment_preimages.insert(hash, preimage) {
2411 return Err(DecodeError::InvalidValue);
2415 let pending_htlcs_updated_len: u64 = Readable::read(reader)?;
2416 let mut pending_htlcs_updated = Vec::with_capacity(cmp::min(pending_htlcs_updated_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2417 for _ in 0..pending_htlcs_updated_len {
2418 pending_htlcs_updated.push(Readable::read(reader)?);
2421 let pending_events_len: u64 = Readable::read(reader)?;
2422 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<events::Event>()));
2423 for _ in 0..pending_events_len {
2424 if let Some(event) = MaybeReadable::read(reader)? {
2425 pending_events.push(event);
2429 let last_block_hash: BlockHash = Readable::read(reader)?;
2431 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2432 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2433 for _ in 0..waiting_threshold_conf_len {
2434 let height_target = Readable::read(reader)?;
2435 let events_len: u64 = Readable::read(reader)?;
2436 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2437 for _ in 0..events_len {
2438 let ev = match <u8 as Readable>::read(reader)? {
2440 let htlc_source = Readable::read(reader)?;
2441 let hash = Readable::read(reader)?;
2442 OnchainEvent::HTLCUpdate {
2443 htlc_update: (htlc_source, hash)
2447 let descriptor = Readable::read(reader)?;
2448 OnchainEvent::MaturingOutput {
2452 _ => return Err(DecodeError::InvalidValue),
2456 onchain_events_waiting_threshold_conf.insert(height_target, events);
2459 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2460 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>>())));
2461 for _ in 0..outputs_to_watch_len {
2462 let txid = Readable::read(reader)?;
2463 let outputs_len: u64 = Readable::read(reader)?;
2464 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2465 for _ in 0..outputs_len {
2466 outputs.push(Readable::read(reader)?);
2468 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2469 return Err(DecodeError::InvalidValue);
2472 let onchain_tx_handler = Readable::read(reader)?;
2474 let lockdown_from_offchain = Readable::read(reader)?;
2475 let local_tx_signed = Readable::read(reader)?;
2477 Ok((last_block_hash.clone(), ChannelMonitor {
2479 commitment_transaction_number_obscure_factor,
2482 broadcasted_local_revokable_script,
2483 remote_payment_script,
2488 current_remote_commitment_txid,
2489 prev_remote_commitment_txid,
2491 their_htlc_base_key,
2492 their_delayed_payment_base_key,
2493 funding_redeemscript,
2494 channel_value_satoshis,
2495 their_cur_revocation_points,
2498 their_to_self_delay,
2501 remote_claimable_outpoints,
2502 remote_commitment_txn_on_chain,
2503 remote_hash_commitment_number,
2505 prev_local_signed_commitment_tx,
2506 current_local_commitment_tx,
2507 current_remote_commitment_number,
2508 current_local_commitment_number,
2511 pending_htlcs_updated,
2514 onchain_events_waiting_threshold_conf,
2519 lockdown_from_offchain,
2523 secp_ctx: Secp256k1::new(),
2530 use bitcoin::blockdata::script::{Script, Builder};
2531 use bitcoin::blockdata::opcodes;
2532 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2533 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2534 use bitcoin::util::bip143;
2535 use bitcoin::hashes::Hash;
2536 use bitcoin::hashes::sha256::Hash as Sha256;
2537 use bitcoin::hashes::hex::FromHex;
2538 use bitcoin::hash_types::Txid;
2540 use chain::transaction::OutPoint;
2541 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2542 use ln::channelmonitor::ChannelMonitor;
2543 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2545 use ln::chan_utils::{HTLCOutputInCommitment, LocalCommitmentTransaction};
2546 use util::test_utils::TestLogger;
2547 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2548 use bitcoin::secp256k1::Secp256k1;
2549 use rand::{thread_rng,Rng};
2551 use chain::keysinterface::InMemoryChannelKeys;
2554 fn test_prune_preimages() {
2555 let secp_ctx = Secp256k1::new();
2556 let logger = Arc::new(TestLogger::new());
2558 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2559 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2561 let mut preimages = Vec::new();
2563 let mut rng = thread_rng();
2565 let mut preimage = PaymentPreimage([0; 32]);
2566 rng.fill_bytes(&mut preimage.0[..]);
2567 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2568 preimages.push((preimage, hash));
2572 macro_rules! preimages_slice_to_htlc_outputs {
2573 ($preimages_slice: expr) => {
2575 let mut res = Vec::new();
2576 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2577 res.push((HTLCOutputInCommitment {
2581 payment_hash: preimage.1.clone(),
2582 transaction_output_index: Some(idx as u32),
2589 macro_rules! preimages_to_local_htlcs {
2590 ($preimages_slice: expr) => {
2592 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2593 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2599 macro_rules! test_preimages_exist {
2600 ($preimages_slice: expr, $monitor: expr) => {
2601 for preimage in $preimages_slice {
2602 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2607 let keys = InMemoryChannelKeys::new(
2609 SecretKey::from_slice(&[41; 32]).unwrap(),
2610 SecretKey::from_slice(&[41; 32]).unwrap(),
2611 SecretKey::from_slice(&[41; 32]).unwrap(),
2612 SecretKey::from_slice(&[41; 32]).unwrap(),
2613 SecretKey::from_slice(&[41; 32]).unwrap(),
2618 // Prune with one old state and a local commitment tx holding a few overlaps with the
2620 let mut monitor = ChannelMonitor::new(keys,
2621 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2622 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2623 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2624 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2625 10, Script::new(), 46, 0, LocalCommitmentTransaction::dummy());
2627 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2628 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2629 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2630 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2631 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2632 for &(ref preimage, ref hash) in preimages.iter() {
2633 monitor.provide_payment_preimage(hash, preimage);
2636 // Now provide a secret, pruning preimages 10-15
2637 let mut secret = [0; 32];
2638 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2639 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2640 assert_eq!(monitor.payment_preimages.len(), 15);
2641 test_preimages_exist!(&preimages[0..10], monitor);
2642 test_preimages_exist!(&preimages[15..20], monitor);
2644 // Now provide a further secret, pruning preimages 15-17
2645 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2646 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2647 assert_eq!(monitor.payment_preimages.len(), 13);
2648 test_preimages_exist!(&preimages[0..10], monitor);
2649 test_preimages_exist!(&preimages[17..20], monitor);
2651 // Now update local commitment tx info, pruning only element 18 as we still care about the
2652 // previous commitment tx's preimages too
2653 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2654 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2655 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2656 assert_eq!(monitor.payment_preimages.len(), 12);
2657 test_preimages_exist!(&preimages[0..10], monitor);
2658 test_preimages_exist!(&preimages[18..20], monitor);
2660 // But if we do it again, we'll prune 5-10
2661 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2662 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2663 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2664 assert_eq!(monitor.payment_preimages.len(), 5);
2665 test_preimages_exist!(&preimages[0..5], monitor);
2669 fn test_claim_txn_weight_computation() {
2670 // We test Claim txn weight, knowing that we want expected weigth and
2671 // not actual case to avoid sigs and time-lock delays hell variances.
2673 let secp_ctx = Secp256k1::new();
2674 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2675 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2676 let mut sum_actual_sigs = 0;
2678 macro_rules! sign_input {
2679 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2680 let htlc = HTLCOutputInCommitment {
2681 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2683 cltv_expiry: 2 << 16,
2684 payment_hash: PaymentHash([1; 32]),
2685 transaction_output_index: Some($idx),
2687 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2688 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2689 let sig = secp_ctx.sign(&sighash, &privkey);
2690 $input.witness.push(sig.serialize_der().to_vec());
2691 $input.witness[0].push(SigHashType::All as u8);
2692 sum_actual_sigs += $input.witness[0].len();
2693 if *$input_type == InputDescriptors::RevokedOutput {
2694 $input.witness.push(vec!(1));
2695 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2696 $input.witness.push(pubkey.clone().serialize().to_vec());
2697 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2698 $input.witness.push(vec![0]);
2700 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2702 $input.witness.push(redeem_script.into_bytes());
2703 println!("witness[0] {}", $input.witness[0].len());
2704 println!("witness[1] {}", $input.witness[1].len());
2705 println!("witness[2] {}", $input.witness[2].len());
2709 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2710 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2712 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2713 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2715 claim_tx.input.push(TxIn {
2716 previous_output: BitcoinOutPoint {
2720 script_sig: Script::new(),
2721 sequence: 0xfffffffd,
2722 witness: Vec::new(),
2725 claim_tx.output.push(TxOut {
2726 script_pubkey: script_pubkey.clone(),
2729 let base_weight = claim_tx.get_weight();
2730 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2731 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2732 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2733 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2735 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));
2737 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2738 claim_tx.input.clear();
2739 sum_actual_sigs = 0;
2741 claim_tx.input.push(TxIn {
2742 previous_output: BitcoinOutPoint {
2746 script_sig: Script::new(),
2747 sequence: 0xfffffffd,
2748 witness: Vec::new(),
2751 let base_weight = claim_tx.get_weight();
2752 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2753 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2754 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2755 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2757 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));
2759 // Justice tx with 1 revoked HTLC-Success tx output
2760 claim_tx.input.clear();
2761 sum_actual_sigs = 0;
2762 claim_tx.input.push(TxIn {
2763 previous_output: BitcoinOutPoint {
2767 script_sig: Script::new(),
2768 sequence: 0xfffffffd,
2769 witness: Vec::new(),
2771 let base_weight = claim_tx.get_weight();
2772 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2773 let inputs_des = vec![InputDescriptors::RevokedOutput];
2774 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2775 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2777 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));
2780 // Further testing is done in the ChannelManager integration tests.