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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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_hashes::hash160::Hash as Hash160;
25 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
27 use secp256k1::{Secp256k1,Signature};
28 use secp256k1::key::{SecretKey,PublicKey};
31 use ln::msgs::DecodeError;
33 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
34 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
35 use ln::onchaintx::OnchainTxHandler;
36 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator};
37 use chain::transaction::OutPoint;
38 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
39 use util::logger::Logger;
40 use util::ser::{ReadableArgs, Readable, MaybeReadable, Writer, Writeable, U48};
41 use util::{byte_utils, events};
43 use std::collections::{HashMap, hash_map};
44 use std::sync::{Arc,Mutex};
45 use std::{hash,cmp, mem};
48 /// An update generated by the underlying Channel itself which contains some new information the
49 /// ChannelMonitor should be made aware of.
50 #[cfg_attr(test, derive(PartialEq))]
53 pub struct ChannelMonitorUpdate {
54 pub(super) updates: Vec<ChannelMonitorUpdateStep>,
55 /// The sequence number of this update. Updates *must* be replayed in-order according to this
56 /// sequence number (and updates may panic if they are not). The update_id values are strictly
57 /// increasing and increase by one for each new update.
59 /// This sequence number is also used to track up to which points updates which returned
60 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
61 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
65 impl Writeable for ChannelMonitorUpdate {
66 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
67 self.update_id.write(w)?;
68 (self.updates.len() as u64).write(w)?;
69 for update_step in self.updates.iter() {
70 update_step.write(w)?;
75 impl Readable for ChannelMonitorUpdate {
76 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
77 let update_id: u64 = Readable::read(r)?;
78 let len: u64 = Readable::read(r)?;
79 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
81 updates.push(Readable::read(r)?);
83 Ok(Self { update_id, updates })
87 /// An error enum representing a failure to persist a channel monitor update.
89 pub enum ChannelMonitorUpdateErr {
90 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
91 /// our state failed, but is expected to succeed at some point in the future).
93 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
94 /// submitting new commitment transactions to the remote party. Once the update(s) which failed
95 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
96 /// restore the channel to an operational state.
98 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
99 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
100 /// writing out the latest ChannelManager state.
102 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
103 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
104 /// to claim it on this channel) and those updates must be applied wherever they can be. At
105 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
106 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
107 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
110 /// Note that even if updates made after TemporaryFailure succeed you must still call
111 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
114 /// Note that the update being processed here will not be replayed for you when you call
115 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
116 /// with the persisted ChannelMonitor on your own local disk prior to returning a
117 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
118 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
121 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
122 /// remote location (with local copies persisted immediately), it is anticipated that all
123 /// updates will return TemporaryFailure until the remote copies could be updated.
125 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
126 /// different watchtower and cannot update with all watchtowers that were previously informed
127 /// of this channel). This will force-close the channel in question (which will generate one
128 /// final ChannelMonitorUpdate which must be delivered to at least one ChannelMonitor copy).
130 /// Should also be used to indicate a failure to update the local persisted copy of the channel
135 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
136 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
137 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
139 /// Contains a human-readable error message.
141 pub struct MonitorUpdateError(pub &'static str);
143 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
144 /// forward channel and from which info are needed to update HTLC in a backward channel.
145 #[derive(Clone, PartialEq)]
146 pub struct HTLCUpdate {
147 pub(super) payment_hash: PaymentHash,
148 pub(super) payment_preimage: Option<PaymentPreimage>,
149 pub(super) source: HTLCSource
151 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
153 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
154 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
155 /// events to it, while also taking any add/update_monitor events and passing them to some remote
158 /// In general, you must always have at least one local copy in memory, which must never fail to
159 /// update (as it is responsible for broadcasting the latest state in case the channel is closed),
160 /// and then persist it to various on-disk locations. If, for some reason, the in-memory copy fails
161 /// to update (eg out-of-memory or some other condition), you must immediately shut down without
162 /// taking any further action such as writing the current state to disk. This should likely be
163 /// accomplished via panic!() or abort().
165 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
166 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
167 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
168 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
170 /// User needs to notify implementors of ManyChannelMonitor when a new block is connected or
171 /// disconnected using their `block_connected` and `block_disconnected` methods. However, rather
172 /// than calling these methods directly, the user should register implementors as listeners to the
173 /// BlockNotifier and call the BlockNotifier's `block_(dis)connected` methods, which will notify
174 /// all registered listeners in one go.
175 pub trait ManyChannelMonitor<ChanSigner: ChannelKeys>: Send + Sync {
176 /// Adds a monitor for the given `funding_txo`.
178 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
179 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
180 /// callbacks with the funding transaction, or any spends of it.
182 /// Further, the implementer must also ensure that each output returned in
183 /// monitor.get_outputs_to_watch() is registered to ensure that the provided monitor learns about
184 /// any spends of any of the outputs.
186 /// Any spends of outputs which should have been registered which aren't passed to
187 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
188 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr>;
190 /// Updates a monitor for the given `funding_txo`.
192 /// Implementer must also ensure that the funding_txo txid *and* outpoint are registered with
193 /// any relevant ChainWatchInterfaces such that the provided monitor receives block_connected
194 /// callbacks with the funding transaction, or any spends of it.
196 /// Further, the implementer must also ensure that each output returned in
197 /// monitor.get_watch_outputs() is registered to ensure that the provided monitor learns about
198 /// any spends of any of the outputs.
200 /// Any spends of outputs which should have been registered which aren't passed to
201 /// ChannelMonitors via block_connected may result in FUNDS LOSS.
202 fn update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr>;
204 /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
205 /// with success or failure.
207 /// You should probably just call through to
208 /// ChannelMonitor::get_and_clear_pending_htlcs_updated() for each ChannelMonitor and return
210 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate>;
213 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
214 /// watchtower or watch our own channels.
216 /// Note that you must provide your own key by which to refer to channels.
218 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
219 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
220 /// index by a PublicKey which is required to sign any updates.
222 /// If you're using this for local monitoring of your own channels, you probably want to use
223 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
224 pub struct SimpleManyChannelMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref>
225 where T::Target: BroadcasterInterface,
226 F::Target: FeeEstimator
228 #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
229 pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
231 monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
232 chain_monitor: Arc<ChainWatchInterface>,
238 impl<'a, Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send>
239 ChainListener for SimpleManyChannelMonitor<Key, ChanSigner, T, F>
240 where T::Target: BroadcasterInterface,
241 F::Target: FeeEstimator
243 fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
244 let block_hash = header.bitcoin_hash();
246 let mut monitors = self.monitors.lock().unwrap();
247 for monitor in monitors.values_mut() {
248 let txn_outputs = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator);
250 for (ref txid, ref outputs) in txn_outputs {
251 for (idx, output) in outputs.iter().enumerate() {
252 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
259 fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
260 let block_hash = header.bitcoin_hash();
261 let mut monitors = self.monitors.lock().unwrap();
262 for monitor in monitors.values_mut() {
263 monitor.block_disconnected(disconnected_height, &block_hash, &*self.broadcaster, &*self.fee_estimator);
268 impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref, F: Deref> SimpleManyChannelMonitor<Key, ChanSigner, T, F>
269 where T::Target: BroadcasterInterface,
270 F::Target: FeeEstimator
272 /// Creates a new object which can be used to monitor several channels given the chain
273 /// interface with which to register to receive notifications.
274 pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: T, logger: Arc<Logger>, feeest: F) -> SimpleManyChannelMonitor<Key, ChanSigner, T, F> {
275 let res = SimpleManyChannelMonitor {
276 monitors: Mutex::new(HashMap::new()),
280 fee_estimator: feeest,
286 /// Adds or updates the monitor which monitors the channel referred to by the given key.
287 pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
288 let mut monitors = self.monitors.lock().unwrap();
289 let entry = match monitors.entry(key) {
290 hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
291 hash_map::Entry::Vacant(e) => e,
293 match monitor.onchain_detection.funding_info {
295 return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !"));
297 Some((ref outpoint, ref script)) => {
298 log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..]));
299 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
300 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
303 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
304 for (idx, script) in outputs.iter().enumerate() {
305 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
308 entry.insert(monitor);
312 /// Updates the monitor which monitors the channel referred to by the given key.
313 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
314 let mut monitors = self.monitors.lock().unwrap();
315 match monitors.get_mut(&key) {
316 Some(orig_monitor) => {
317 log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor.onchain_detection));
318 orig_monitor.update_monitor(update, &self.broadcaster)
320 None => Err(MonitorUpdateError("No such monitor registered"))
325 impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F>
326 where T::Target: BroadcasterInterface,
327 F::Target: FeeEstimator
329 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
330 match self.add_monitor_by_key(funding_txo, monitor) {
332 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
336 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
337 match self.update_monitor_by_key(funding_txo, update) {
339 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
343 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {
344 let mut pending_htlcs_updated = Vec::new();
345 for chan in self.monitors.lock().unwrap().values_mut() {
346 pending_htlcs_updated.append(&mut chan.get_and_clear_pending_htlcs_updated());
348 pending_htlcs_updated
352 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F>
353 where T::Target: BroadcasterInterface,
354 F::Target: FeeEstimator
356 fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
357 let mut pending_events = Vec::new();
358 for chan in self.monitors.lock().unwrap().values_mut() {
359 pending_events.append(&mut chan.get_and_clear_pending_events());
365 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
366 /// instead claiming it in its own individual transaction.
367 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
368 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
369 /// HTLC-Success transaction.
370 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
371 /// transaction confirmed (and we use it in a few more, equivalent, places).
372 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
373 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
374 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
375 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
376 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
377 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
378 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
379 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
380 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
381 /// accurate block height.
382 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
383 /// with at worst this delay, so we are not only using this value as a mercy for them but also
384 /// us as a safeguard to delay with enough time.
385 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
386 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
387 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
388 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
389 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
390 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
391 /// keeping bumping another claim tx to solve the outpoint.
392 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
394 struct OnchainDetection<ChanSigner: ChannelKeys> {
396 funding_info: Option<(OutPoint, Script)>,
397 current_remote_commitment_txid: Option<Sha256dHash>,
398 prev_remote_commitment_txid: Option<Sha256dHash>,
401 #[cfg(any(test, feature = "fuzztarget"))]
402 impl<ChanSigner: ChannelKeys> PartialEq for OnchainDetection<ChanSigner> {
403 fn eq(&self, other: &Self) -> bool {
404 self.keys.pubkeys() == other.keys.pubkeys()
408 #[derive(Clone, PartialEq)]
409 struct LocalSignedTx {
410 /// txid of the transaction in tx, just used to make comparison faster
412 tx: LocalCommitmentTransaction,
413 revocation_key: PublicKey,
414 a_htlc_key: PublicKey,
415 b_htlc_key: PublicKey,
416 delayed_payment_key: PublicKey,
417 per_commitment_point: PublicKey,
419 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
422 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
423 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
424 /// a new bumped one in case of lenghty confirmation delay
425 #[derive(Clone, PartialEq)]
426 pub(crate) enum InputMaterial {
428 witness_script: Script,
429 pubkey: Option<PublicKey>,
435 witness_script: Script,
437 preimage: Option<PaymentPreimage>,
442 witness_script: Script,
443 sigs: (Signature, Signature),
444 preimage: Option<PaymentPreimage>,
452 impl Writeable for InputMaterial {
453 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
455 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount} => {
456 writer.write_all(&[0; 1])?;
457 witness_script.write(writer)?;
458 pubkey.write(writer)?;
459 writer.write_all(&key[..])?;
460 is_htlc.write(writer)?;
461 writer.write_all(&byte_utils::be64_to_array(*amount))?;
463 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
464 writer.write_all(&[1; 1])?;
465 witness_script.write(writer)?;
467 preimage.write(writer)?;
468 writer.write_all(&byte_utils::be64_to_array(*amount))?;
469 writer.write_all(&byte_utils::be32_to_array(*locktime))?;
471 &InputMaterial::LocalHTLC { ref witness_script, ref sigs, ref preimage, ref amount } => {
472 writer.write_all(&[2; 1])?;
473 witness_script.write(writer)?;
474 sigs.0.write(writer)?;
475 sigs.1.write(writer)?;
476 preimage.write(writer)?;
477 writer.write_all(&byte_utils::be64_to_array(*amount))?;
479 &InputMaterial::Funding { ref channel_value } => {
480 writer.write_all(&[3; 1])?;
481 channel_value.write(writer)?;
488 impl Readable for InputMaterial {
489 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
490 let input_material = match <u8 as Readable>::read(reader)? {
492 let witness_script = Readable::read(reader)?;
493 let pubkey = Readable::read(reader)?;
494 let key = Readable::read(reader)?;
495 let is_htlc = Readable::read(reader)?;
496 let amount = Readable::read(reader)?;
497 InputMaterial::Revoked {
506 let witness_script = Readable::read(reader)?;
507 let key = Readable::read(reader)?;
508 let preimage = Readable::read(reader)?;
509 let amount = Readable::read(reader)?;
510 let locktime = Readable::read(reader)?;
511 InputMaterial::RemoteHTLC {
520 let witness_script = Readable::read(reader)?;
521 let their_sig = Readable::read(reader)?;
522 let our_sig = Readable::read(reader)?;
523 let preimage = Readable::read(reader)?;
524 let amount = Readable::read(reader)?;
525 InputMaterial::LocalHTLC {
527 sigs: (their_sig, our_sig),
533 let channel_value = Readable::read(reader)?;
534 InputMaterial::Funding {
538 _ => return Err(DecodeError::InvalidValue),
544 /// ClaimRequest is a descriptor structure to communicate between detection
545 /// and reaction module. They are generated by ChannelMonitor while parsing
546 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
547 /// is responsible for opportunistic aggregation, selecting and enforcing
548 /// bumping logic, building and signing transactions.
549 pub(crate) struct ClaimRequest {
550 // Block height before which claiming is exclusive to one party,
551 // after reaching it, claiming may be contentious.
552 pub(crate) absolute_timelock: u32,
553 // Timeout tx must have nLocktime set which means aggregating multiple
554 // ones must take the higher nLocktime among them to satisfy all of them.
555 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
556 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
557 // Do simplify we mark them as non-aggregable.
558 pub(crate) aggregable: bool,
559 // Basic bitcoin outpoint (txid, vout)
560 pub(crate) outpoint: BitcoinOutPoint,
561 // Following outpoint type, set of data needed to generate transaction digest
562 // and satisfy witness program.
563 pub(crate) witness_data: InputMaterial
566 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
567 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
568 #[derive(Clone, PartialEq)]
570 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
571 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
572 /// only win from it, so it's never an OnchainEvent
574 htlc_update: (HTLCSource, PaymentHash),
577 descriptor: SpendableOutputDescriptor,
581 const SERIALIZATION_VERSION: u8 = 1;
582 const MIN_SERIALIZATION_VERSION: u8 = 1;
584 #[cfg_attr(test, derive(PartialEq))]
586 pub(super) enum ChannelMonitorUpdateStep {
587 LatestLocalCommitmentTXInfo {
588 // TODO: We really need to not be generating a fully-signed transaction in Channel and
589 // passing it here, we need to hold off so that the ChanSigner can enforce a
590 // only-sign-local-state-for-broadcast once invariant:
591 commitment_tx: LocalCommitmentTransaction,
592 local_keys: chan_utils::TxCreationKeys,
594 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
596 LatestRemoteCommitmentTXInfo {
597 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
598 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
599 commitment_number: u64,
600 their_revocation_point: PublicKey,
603 payment_preimage: PaymentPreimage,
609 /// Indicates our channel is likely a stale version, we're closing, but this update should
610 /// allow us to spend what is ours if our counterparty broadcasts their latest state.
611 RescueRemoteCommitmentTXInfo {
612 their_current_per_commitment_point: PublicKey,
614 /// Used to indicate that the no future updates will occur, and likely that the latest local
615 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
617 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
618 /// think we've fallen behind!
619 should_broadcast: bool,
623 impl Writeable for ChannelMonitorUpdateStep {
624 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
626 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref local_keys, ref feerate_per_kw, ref htlc_outputs } => {
628 commitment_tx.write(w)?;
629 local_keys.write(w)?;
630 feerate_per_kw.write(w)?;
631 (htlc_outputs.len() as u64).write(w)?;
632 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
638 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
640 unsigned_commitment_tx.write(w)?;
641 commitment_number.write(w)?;
642 their_revocation_point.write(w)?;
643 (htlc_outputs.len() as u64).write(w)?;
644 for &(ref output, ref source) in htlc_outputs.iter() {
646 source.as_ref().map(|b| b.as_ref()).write(w)?;
649 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
651 payment_preimage.write(w)?;
653 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
658 &ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { ref their_current_per_commitment_point } => {
660 their_current_per_commitment_point.write(w)?;
662 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
664 should_broadcast.write(w)?;
670 impl Readable for ChannelMonitorUpdateStep {
671 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
672 match Readable::read(r)? {
674 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
675 commitment_tx: Readable::read(r)?,
676 local_keys: Readable::read(r)?,
677 feerate_per_kw: Readable::read(r)?,
679 let len: u64 = Readable::read(r)?;
680 let mut res = Vec::new();
682 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
689 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
690 unsigned_commitment_tx: Readable::read(r)?,
691 commitment_number: Readable::read(r)?,
692 their_revocation_point: Readable::read(r)?,
694 let len: u64 = Readable::read(r)?;
695 let mut res = Vec::new();
697 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
704 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
705 payment_preimage: Readable::read(r)?,
709 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
710 idx: Readable::read(r)?,
711 secret: Readable::read(r)?,
715 Ok(ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo {
716 their_current_per_commitment_point: Readable::read(r)?,
720 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
721 should_broadcast: Readable::read(r)?
724 _ => Err(DecodeError::InvalidValue),
729 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
730 /// on-chain transactions to ensure no loss of funds occurs.
732 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
733 /// information and are actively monitoring the chain.
735 /// Pending Events or updated HTLCs which have not yet been read out by
736 /// get_and_clear_pending_htlcs_updated or get_and_clear_pending_events are serialized to disk and
737 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
738 /// gotten are fully handled before re-serializing the new state.
739 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
740 latest_update_id: u64,
741 commitment_transaction_number_obscure_factor: u64,
743 destination_script: Script,
744 broadcasted_local_revokable_script: Option<(Script, SecretKey, Script)>,
745 broadcasted_remote_payment_script: Option<(Script, SecretKey)>,
746 shutdown_script: Script,
748 onchain_detection: OnchainDetection<ChanSigner>,
749 their_htlc_base_key: Option<PublicKey>,
750 their_delayed_payment_base_key: Option<PublicKey>,
751 funding_redeemscript: Option<Script>,
752 channel_value_satoshis: Option<u64>,
753 // first is the idx of the first of the two revocation points
754 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
756 our_to_self_delay: u16,
757 their_to_self_delay: Option<u16>,
759 commitment_secrets: CounterpartyCommitmentSecrets,
760 remote_claimable_outpoints: HashMap<Sha256dHash, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
761 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
762 /// Nor can we figure out their commitment numbers without the commitment transaction they are
763 /// spending. Thus, in order to claim them via revocation key, we track all the remote
764 /// commitment transactions which we find on-chain, mapping them to the commitment number which
765 /// can be used to derive the revocation key and claim the transactions.
766 remote_commitment_txn_on_chain: HashMap<Sha256dHash, (u64, Vec<Script>)>,
767 /// Cache used to make pruning of payment_preimages faster.
768 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
769 /// remote transactions (ie should remain pretty small).
770 /// Serialized to disk but should generally not be sent to Watchtowers.
771 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
773 // We store two local commitment transactions to avoid any race conditions where we may update
774 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
775 // various monitors for one channel being out of sync, and us broadcasting a local
776 // transaction for which we have deleted claim information on some watchtowers.
777 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
778 current_local_signed_commitment_tx: Option<LocalSignedTx>,
780 // Used just for ChannelManager to make sure it has the latest channel data during
782 current_remote_commitment_number: u64,
783 // Used just for ChannelManager to make sure it has the latest channel data during
785 current_local_commitment_number: u64,
787 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
789 pending_htlcs_updated: Vec<HTLCUpdate>,
790 pending_events: Vec<events::Event>,
792 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
793 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
794 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
795 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
797 // If we get serialized out and re-read, we need to make sure that the chain monitoring
798 // interface knows about the TXOs that we want to be notified of spends of. We could probably
799 // be smart and derive them from the above storage fields, but its much simpler and more
800 // Obviously Correct (tm) if we just keep track of them explicitly.
801 outputs_to_watch: HashMap<Sha256dHash, Vec<Script>>,
804 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
806 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
808 // We simply modify last_block_hash in Channel's block_connected so that serialization is
809 // consistent but hopefully the users' copy handles block_connected in a consistent way.
810 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
811 // their last_block_hash from its state and not based on updated copies that didn't run through
812 // the full block_connected).
813 pub(crate) last_block_hash: Sha256dHash,
814 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
818 #[cfg(any(test, feature = "fuzztarget"))]
819 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
820 /// underlying object
821 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
822 fn eq(&self, other: &Self) -> bool {
823 if self.latest_update_id != other.latest_update_id ||
824 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
825 self.destination_script != other.destination_script ||
826 self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
827 self.broadcasted_remote_payment_script != other.broadcasted_remote_payment_script ||
828 self.onchain_detection != other.onchain_detection ||
829 self.their_htlc_base_key != other.their_htlc_base_key ||
830 self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
831 self.funding_redeemscript != other.funding_redeemscript ||
832 self.channel_value_satoshis != other.channel_value_satoshis ||
833 self.their_cur_revocation_points != other.their_cur_revocation_points ||
834 self.our_to_self_delay != other.our_to_self_delay ||
835 self.their_to_self_delay != other.their_to_self_delay ||
836 self.commitment_secrets != other.commitment_secrets ||
837 self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
838 self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
839 self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
840 self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
841 self.current_remote_commitment_number != other.current_remote_commitment_number ||
842 self.current_local_commitment_number != other.current_local_commitment_number ||
843 self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
844 self.payment_preimages != other.payment_preimages ||
845 self.pending_htlcs_updated != other.pending_htlcs_updated ||
846 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
847 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
848 self.outputs_to_watch != other.outputs_to_watch
857 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
858 /// Serializes into a vec, with various modes for the exposed pub fns
859 fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
860 //TODO: We still write out all the serialization here manually instead of using the fancy
861 //serialization framework we have, we should migrate things over to it.
862 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
863 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
865 self.latest_update_id.write(writer)?;
867 // Set in initial Channel-object creation, so should always be set by now:
868 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
870 self.destination_script.write(writer)?;
871 if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
872 writer.write_all(&[0; 1])?;
873 broadcasted_local_revokable_script.0.write(writer)?;
874 broadcasted_local_revokable_script.1.write(writer)?;
875 broadcasted_local_revokable_script.2.write(writer)?;
877 writer.write_all(&[1; 1])?;
880 if let Some(ref broadcasted_remote_payment_script) = self.broadcasted_remote_payment_script {
881 writer.write_all(&[0; 1])?;
882 broadcasted_remote_payment_script.0.write(writer)?;
883 broadcasted_remote_payment_script.1.write(writer)?;
885 writer.write_all(&[1; 1])?;
887 self.shutdown_script.write(writer)?;
889 self.onchain_detection.keys.write(writer)?;
890 match self.onchain_detection.funding_info {
891 Some((ref outpoint, ref script)) => {
892 writer.write_all(&outpoint.txid[..])?;
893 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
894 script.write(writer)?;
897 debug_assert!(false, "Try to serialize a useless Local monitor !");
900 self.onchain_detection.current_remote_commitment_txid.write(writer)?;
901 self.onchain_detection.prev_remote_commitment_txid.write(writer)?;
903 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
904 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
905 self.funding_redeemscript.as_ref().unwrap().write(writer)?;
906 self.channel_value_satoshis.unwrap().write(writer)?;
908 match self.their_cur_revocation_points {
909 Some((idx, pubkey, second_option)) => {
910 writer.write_all(&byte_utils::be48_to_array(idx))?;
911 writer.write_all(&pubkey.serialize())?;
912 match second_option {
913 Some(second_pubkey) => {
914 writer.write_all(&second_pubkey.serialize())?;
917 writer.write_all(&[0; 33])?;
922 writer.write_all(&byte_utils::be48_to_array(0))?;
926 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
927 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
929 self.commitment_secrets.write(writer)?;
931 macro_rules! serialize_htlc_in_commitment {
932 ($htlc_output: expr) => {
933 writer.write_all(&[$htlc_output.offered as u8; 1])?;
934 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
935 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
936 writer.write_all(&$htlc_output.payment_hash.0[..])?;
937 $htlc_output.transaction_output_index.write(writer)?;
941 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
942 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
943 writer.write_all(&txid[..])?;
944 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
945 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
946 serialize_htlc_in_commitment!(htlc_output);
947 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
951 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
952 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
953 writer.write_all(&txid[..])?;
954 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
955 (txouts.len() as u64).write(writer)?;
956 for script in txouts.iter() {
957 script.write(writer)?;
961 if for_local_storage {
962 writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
963 for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
964 writer.write_all(&payment_hash.0[..])?;
965 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
968 writer.write_all(&byte_utils::be64_to_array(0))?;
971 macro_rules! serialize_local_tx {
972 ($local_tx: expr) => {
973 $local_tx.tx.write(writer)?;
974 writer.write_all(&$local_tx.revocation_key.serialize())?;
975 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
976 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
977 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
978 writer.write_all(&$local_tx.per_commitment_point.serialize())?;
980 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
981 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
982 for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
983 serialize_htlc_in_commitment!(htlc_output);
984 if let &Some(ref their_sig) = sig {
986 writer.write_all(&their_sig.serialize_compact())?;
990 htlc_source.write(writer)?;
995 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
996 writer.write_all(&[1; 1])?;
997 serialize_local_tx!(prev_local_tx);
999 writer.write_all(&[0; 1])?;
1002 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1003 writer.write_all(&[1; 1])?;
1004 serialize_local_tx!(cur_local_tx);
1006 writer.write_all(&[0; 1])?;
1009 if for_local_storage {
1010 writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
1012 writer.write_all(&byte_utils::be48_to_array(0))?;
1015 if for_local_storage {
1016 writer.write_all(&byte_utils::be48_to_array(self.current_local_commitment_number))?;
1018 writer.write_all(&byte_utils::be48_to_array(0))?;
1021 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1022 for payment_preimage in self.payment_preimages.values() {
1023 writer.write_all(&payment_preimage.0[..])?;
1026 writer.write_all(&byte_utils::be64_to_array(self.pending_htlcs_updated.len() as u64))?;
1027 for data in self.pending_htlcs_updated.iter() {
1028 data.write(writer)?;
1031 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1032 for event in self.pending_events.iter() {
1033 event.write(writer)?;
1036 self.last_block_hash.write(writer)?;
1038 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1039 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1040 writer.write_all(&byte_utils::be32_to_array(**target))?;
1041 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1042 for ev in events.iter() {
1044 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1046 htlc_update.0.write(writer)?;
1047 htlc_update.1.write(writer)?;
1049 OnchainEvent::MaturingOutput { ref descriptor } => {
1051 descriptor.write(writer)?;
1057 (self.outputs_to_watch.len() as u64).write(writer)?;
1058 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1059 txid.write(writer)?;
1060 (output_scripts.len() as u64).write(writer)?;
1061 for script in output_scripts.iter() {
1062 script.write(writer)?;
1065 self.onchain_tx_handler.write(writer)?;
1070 /// Writes this monitor into the given writer, suitable for writing to disk.
1072 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1073 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1074 /// the "reorg path" (ie not just starting at the same height but starting at the highest
1075 /// common block that appears on your best chain as well as on the chain which contains the
1076 /// last block hash returned) upon deserializing the object!
1077 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1078 self.write(writer, true)
1081 /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
1083 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1084 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1085 /// the "reorg path" (ie not just starting at the same height but starting at the highest
1086 /// common block that appears on your best chain as well as on the chain which contains the
1087 /// last block hash returned) upon deserializing the object!
1088 pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1089 self.write(writer, false)
1093 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1094 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1095 our_to_self_delay: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1096 their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey,
1097 their_to_self_delay: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1098 commitment_transaction_number_obscure_factor: u64,
1099 logger: Arc<Logger>) -> ChannelMonitor<ChanSigner> {
1101 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1102 let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
1103 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1105 let onchain_detection = OnchainDetection {
1107 funding_info: Some(funding_info.clone()),
1108 current_remote_commitment_txid: None,
1109 prev_remote_commitment_txid: None,
1113 latest_update_id: 0,
1114 commitment_transaction_number_obscure_factor,
1116 destination_script: destination_script.clone(),
1117 broadcasted_local_revokable_script: None,
1118 broadcasted_remote_payment_script: None,
1121 onchain_detection: onchain_detection,
1122 their_htlc_base_key: Some(their_htlc_base_key.clone()),
1123 their_delayed_payment_base_key: Some(their_delayed_payment_base_key.clone()),
1124 funding_redeemscript: Some(funding_redeemscript.clone()),
1125 channel_value_satoshis: Some(channel_value_satoshis),
1126 their_cur_revocation_points: None,
1128 our_to_self_delay: our_to_self_delay,
1129 their_to_self_delay: Some(their_to_self_delay),
1131 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1132 remote_claimable_outpoints: HashMap::new(),
1133 remote_commitment_txn_on_chain: HashMap::new(),
1134 remote_hash_commitment_number: HashMap::new(),
1136 prev_local_signed_commitment_tx: None,
1137 current_local_signed_commitment_tx: None,
1138 current_remote_commitment_number: 1 << 48,
1139 current_local_commitment_number: 0xffff_ffff_ffff,
1141 payment_preimages: HashMap::new(),
1142 pending_htlcs_updated: Vec::new(),
1143 pending_events: Vec::new(),
1145 onchain_events_waiting_threshold_conf: HashMap::new(),
1146 outputs_to_watch: HashMap::new(),
1148 onchain_tx_handler: OnchainTxHandler::new(destination_script.clone(), keys, funding_redeemscript, their_to_self_delay, logger.clone()),
1150 last_block_hash: Default::default(),
1151 secp_ctx: Secp256k1::new(),
1156 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1157 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1158 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1159 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1160 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1161 return Err(MonitorUpdateError("Previous secret did not match new one"));
1164 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1165 // events for now-revoked/fulfilled HTLCs.
1166 if let Some(txid) = self.onchain_detection.prev_remote_commitment_txid.take() {
1167 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1172 if !self.payment_preimages.is_empty() {
1173 let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
1174 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1175 let min_idx = self.get_min_seen_secret();
1176 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1178 self.payment_preimages.retain(|&k, _| {
1179 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
1180 if k == htlc.payment_hash {
1184 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1185 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1186 if k == htlc.payment_hash {
1191 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1198 remote_hash_commitment_number.remove(&k);
1207 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1208 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1209 /// possibly future revocation/preimage information) to claim outputs where possible.
1210 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1211 pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey) {
1212 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1213 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1214 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1216 for &(ref htlc, _) in &htlc_outputs {
1217 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1220 let new_txid = unsigned_commitment_tx.txid();
1221 log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1222 log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1223 self.onchain_detection.prev_remote_commitment_txid = self.onchain_detection.current_remote_commitment_txid.take();
1224 self.onchain_detection.current_remote_commitment_txid = Some(new_txid);
1225 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
1226 self.current_remote_commitment_number = commitment_number;
1227 //TODO: Merge this into the other per-remote-transaction output storage stuff
1228 match self.their_cur_revocation_points {
1229 Some(old_points) => {
1230 if old_points.0 == commitment_number + 1 {
1231 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1232 } else if old_points.0 == commitment_number + 2 {
1233 if let Some(old_second_point) = old_points.2 {
1234 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1236 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1239 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1243 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1248 pub(super) fn provide_rescue_remote_commitment_tx_info(&mut self, their_revocation_point: PublicKey) {
1249 if let Ok(payment_key) = chan_utils::derive_public_key(&self.secp_ctx, &their_revocation_point, &self.onchain_detection.keys.pubkeys().payment_basepoint) {
1250 let to_remote_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1251 .push_slice(&Hash160::hash(&payment_key.serialize())[..])
1253 if let Ok(to_remote_key) = chan_utils::derive_private_key(&self.secp_ctx, &their_revocation_point, &self.onchain_detection.keys.payment_base_key()) {
1254 self.broadcasted_remote_payment_script = Some((to_remote_script, to_remote_key));
1259 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1260 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1261 /// is important that any clones of this channel monitor (including remote clones) by kept
1262 /// up-to-date as our local commitment transaction is updated.
1263 /// Panics if set_their_to_self_delay has never been called.
1264 pub(super) fn provide_latest_local_commitment_tx_info(&mut self, commitment_tx: LocalCommitmentTransaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1265 if self.their_to_self_delay.is_none() {
1266 return Err(MonitorUpdateError("Got a local commitment tx info update before we'd set basic information about the channel"));
1268 // Returning a monitor error before updating tracking points means in case of using
1269 // a concurrent watchtower implementation for same channel, if this one doesn't
1270 // reject update as we do, you MAY have the latest local valid commitment tx onchain
1271 // for which you want to spend outputs. We're NOT robust again this scenario right
1272 // now but we should consider it later.
1273 if let Err(_) = self.onchain_tx_handler.provide_latest_local_tx(commitment_tx.clone(), local_keys.clone(), feerate_per_kw, htlc_outputs.clone()) {
1274 return Err(MonitorUpdateError("Local commitment signed has already been signed, no further update of LOCAL commitment transaction is allowed"));
1276 self.current_local_commitment_number = 0xffff_ffff_ffff - ((((commitment_tx.without_valid_witness().input[0].sequence as u64 & 0xffffff) << 3*8) | (commitment_tx.without_valid_witness().lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1277 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
1278 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
1279 txid: commitment_tx.txid(),
1281 revocation_key: local_keys.revocation_key,
1282 a_htlc_key: local_keys.a_htlc_key,
1283 b_htlc_key: local_keys.b_htlc_key,
1284 delayed_payment_key: local_keys.a_delayed_payment_key,
1285 per_commitment_point: local_keys.per_commitment_point,
1287 htlc_outputs: htlc_outputs,
1292 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1293 /// commitment_tx_infos which contain the payment hash have been revoked.
1294 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1295 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1298 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref>(&mut self, broadcaster: &B)
1299 where B::Target: BroadcasterInterface,
1301 for tx in self.get_latest_local_commitment_txn().iter() {
1302 broadcaster.broadcast_transaction(tx);
1306 /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
1307 pub(super) fn update_monitor_ooo(&mut self, mut updates: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
1308 for update in updates.updates.drain(..) {
1310 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
1311 self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
1312 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1313 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
1314 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1315 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1316 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1317 self.provide_secret(idx, secret)?,
1318 ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
1319 self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
1320 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
1323 self.latest_update_id = updates.update_id;
1327 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1330 /// panics if the given update is not the next update by update_id.
1331 pub fn update_monitor<B: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B) -> Result<(), MonitorUpdateError>
1332 where B::Target: BroadcasterInterface,
1334 if self.latest_update_id + 1 != updates.update_id {
1335 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1337 for update in updates.updates.drain(..) {
1339 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
1340 self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
1341 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1342 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
1343 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1344 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1345 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1346 self.provide_secret(idx, secret)?,
1347 ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
1348 self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
1349 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1350 if should_broadcast {
1351 self.broadcast_latest_local_commitment_txn(broadcaster);
1353 log_error!(self, "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");
1358 self.latest_update_id = updates.update_id;
1362 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1364 pub fn get_latest_update_id(&self) -> u64 {
1365 self.latest_update_id
1368 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1369 pub fn get_funding_txo(&self) -> Option<OutPoint> {
1370 if let Some((outp, _)) = self.onchain_detection.funding_info {
1376 /// Gets a list of txids, with their output scripts (in the order they appear in the
1377 /// transaction), which we must learn about spends of via block_connected().
1378 pub fn get_outputs_to_watch(&self) -> &HashMap<Sha256dHash, Vec<Script>> {
1379 &self.outputs_to_watch
1382 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1383 /// Generally useful when deserializing as during normal operation the return values of
1384 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1385 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1386 pub fn get_monitored_outpoints(&self) -> Vec<(Sha256dHash, u32, &Script)> {
1387 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1388 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1389 for (idx, output) in outputs.iter().enumerate() {
1390 res.push(((*txid).clone(), idx as u32, output));
1396 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1397 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_htlcs_updated().
1398 pub fn get_and_clear_pending_htlcs_updated(&mut self) -> Vec<HTLCUpdate> {
1399 let mut ret = Vec::new();
1400 mem::swap(&mut ret, &mut self.pending_htlcs_updated);
1404 /// Gets the list of pending events which were generated by previous actions, clearing the list
1407 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1408 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1409 /// no internal locking in ChannelMonitors.
1410 pub fn get_and_clear_pending_events(&mut self) -> Vec<events::Event> {
1411 let mut ret = Vec::new();
1412 mem::swap(&mut ret, &mut self.pending_events);
1416 /// Can only fail if idx is < get_min_seen_secret
1417 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1418 self.commitment_secrets.get_secret(idx)
1421 pub(super) fn get_min_seen_secret(&self) -> u64 {
1422 self.commitment_secrets.get_min_seen_secret()
1425 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1426 self.current_remote_commitment_number
1429 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1430 self.current_local_commitment_number
1433 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1434 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1435 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1436 /// HTLC-Success/HTLC-Timeout transactions.
1437 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1438 /// revoked remote commitment tx
1439 fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<ClaimRequest>, (Sha256dHash, Vec<TxOut>)) {
1440 // Most secp and related errors trying to create keys means we have no hope of constructing
1441 // a spend transaction...so we return no transactions to broadcast
1442 let mut claimable_outpoints = Vec::new();
1443 let mut watch_outputs = Vec::new();
1445 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1446 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1448 macro_rules! ignore_error {
1449 ( $thing : expr ) => {
1452 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1457 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);
1458 if commitment_number >= self.get_min_seen_secret() {
1459 let secret = self.get_secret(commitment_number).unwrap();
1460 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1461 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1462 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
1463 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
1464 let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().htlc_basepoint));
1465 let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.payment_base_key()));
1466 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.unwrap()));
1467 let a_htlc_key = match self.their_htlc_base_key {
1468 None => return (claimable_outpoints, (commitment_txid, watch_outputs)),
1469 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
1472 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1473 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1475 self.broadcasted_remote_payment_script = {
1476 // Note that the Network here is ignored as we immediately drop the address for the
1477 // script_pubkey version
1478 let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &local_payment_key).serialize());
1479 Some((Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script(), local_payment_key))
1482 // First, process non-htlc outputs (to_local & to_remote)
1483 for (idx, outp) in tx.output.iter().enumerate() {
1484 if outp.script_pubkey == revokeable_p2wsh {
1485 let witness_data = InputMaterial::Revoked { witness_script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: outp.value };
1486 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});
1490 // Then, try to find revoked htlc outputs
1491 if let Some(ref per_commitment_data) = per_commitment_option {
1492 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1493 if let Some(transaction_output_index) = htlc.transaction_output_index {
1494 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1495 if transaction_output_index as usize >= tx.output.len() ||
1496 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1497 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1498 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1500 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 };
1501 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1506 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1507 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1508 // We're definitely a remote commitment transaction!
1509 log_trace!(self, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1510 watch_outputs.append(&mut tx.output.clone());
1511 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1513 macro_rules! check_htlc_fails {
1514 ($txid: expr, $commitment_tx: expr) => {
1515 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1516 for &(ref htlc, ref source_option) in outpoints.iter() {
1517 if let &Some(ref source) = source_option {
1518 log_info!(self, "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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1519 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1520 hash_map::Entry::Occupied(mut entry) => {
1521 let e = entry.get_mut();
1522 e.retain(|ref event| {
1524 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1525 return htlc_update.0 != **source
1530 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1532 hash_map::Entry::Vacant(entry) => {
1533 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1541 if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
1542 check_htlc_fails!(txid, "current");
1544 if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
1545 check_htlc_fails!(txid, "remote");
1547 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1549 } else if let Some(per_commitment_data) = per_commitment_option {
1550 // While this isn't useful yet, there is a potential race where if a counterparty
1551 // revokes a state at the same time as the commitment transaction for that state is
1552 // confirmed, and the watchtower receives the block before the user, the user could
1553 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1554 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1555 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1557 watch_outputs.append(&mut tx.output.clone());
1558 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1560 log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1562 macro_rules! check_htlc_fails {
1563 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1564 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1565 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1566 if let &Some(ref source) = source_option {
1567 // Check if the HTLC is present in the commitment transaction that was
1568 // broadcast, but not if it was below the dust limit, which we should
1569 // fail backwards immediately as there is no way for us to learn the
1570 // payment_preimage.
1571 // Note that if the dust limit were allowed to change between
1572 // commitment transactions we'd want to be check whether *any*
1573 // broadcastable commitment transaction has the HTLC in it, but it
1574 // cannot currently change after channel initialization, so we don't
1576 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1577 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1581 log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1582 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1583 hash_map::Entry::Occupied(mut entry) => {
1584 let e = entry.get_mut();
1585 e.retain(|ref event| {
1587 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1588 return htlc_update.0 != **source
1593 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1595 hash_map::Entry::Vacant(entry) => {
1596 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1604 if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
1605 check_htlc_fails!(txid, "current", 'current_loop);
1607 if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
1608 check_htlc_fails!(txid, "previous", 'prev_loop);
1611 if let Some(revocation_points) = self.their_cur_revocation_points {
1612 let revocation_point_option =
1613 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1614 else if let Some(point) = revocation_points.2.as_ref() {
1615 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1617 if let Some(revocation_point) = revocation_point_option {
1618 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
1619 let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.pubkeys().htlc_basepoint));
1620 let htlc_privkey = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.htlc_base_key()));
1621 let a_htlc_key = match self.their_htlc_base_key {
1622 None => return (claimable_outpoints, (commitment_txid, watch_outputs)),
1623 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1625 let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.payment_base_key()));
1627 self.broadcasted_remote_payment_script = {
1628 // Note that the Network here is ignored as we immediately drop the address for the
1629 // script_pubkey version
1630 let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &local_payment_key).serialize());
1631 Some((Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script(), local_payment_key))
1634 // Then, try to find htlc outputs
1635 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1636 if let Some(transaction_output_index) = htlc.transaction_output_index {
1637 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1638 if transaction_output_index as usize >= tx.output.len() ||
1639 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1640 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1641 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1643 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1644 let aggregable = if !htlc.offered { false } else { true };
1645 if preimage.is_some() || !htlc.offered {
1646 let witness_data = InputMaterial::RemoteHTLC { witness_script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry };
1647 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1654 (claimable_outpoints, (commitment_txid, watch_outputs))
1657 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1658 fn check_spend_remote_htlc(&mut self, tx: &Transaction, commitment_number: u64, height: u32) -> (Vec<ClaimRequest>, Option<(Sha256dHash, Vec<TxOut>)>) {
1659 let htlc_txid = tx.txid();
1660 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1661 return (Vec::new(), None)
1664 macro_rules! ignore_error {
1665 ( $thing : expr ) => {
1668 Err(_) => return (Vec::new(), None)
1673 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1674 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1675 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1676 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
1677 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
1678 let delayed_key = match self.their_delayed_payment_base_key {
1679 None => return (Vec::new(), None),
1680 Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1682 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1684 log_trace!(self, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1685 let witness_data = InputMaterial::Revoked { witness_script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: tx.output[0].value };
1686 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 });
1687 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1690 fn broadcast_by_local_state(&self, commitment_tx: &Transaction, local_tx: &LocalSignedTx) -> (Vec<Transaction>, Vec<TxOut>, Option<(Script, SecretKey, Script)>) {
1691 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1692 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1694 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
1695 let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, self.onchain_detection.keys.delayed_payment_base_key()) {
1696 Some((redeemscript.to_v0_p2wsh(), local_delayedkey, redeemscript))
1699 for &(ref htlc, ref sigs, _) in local_tx.htlc_outputs.iter() {
1700 if let Some(transaction_output_index) = htlc.transaction_output_index {
1701 if let &Some(ref their_sig) = sigs {
1703 log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions");
1704 let mut htlc_timeout_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
1705 self.onchain_detection.keys.sign_htlc_transaction(&mut htlc_timeout_tx, their_sig, &None, htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key, &local_tx.per_commitment_point, &self.secp_ctx);
1707 log_trace!(self, "Outpoint {}:{} is being being claimed", htlc_timeout_tx.input[0].previous_output.vout, htlc_timeout_tx.input[0].previous_output.txid);
1708 res.push(htlc_timeout_tx);
1710 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1711 log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions");
1712 let mut htlc_success_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
1713 self.onchain_detection.keys.sign_htlc_transaction(&mut htlc_success_tx, their_sig, &Some(*payment_preimage), htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key, &local_tx.per_commitment_point, &self.secp_ctx);
1715 log_trace!(self, "Outpoint {}:{} is being being claimed", htlc_success_tx.input[0].previous_output.vout, htlc_success_tx.input[0].previous_output.txid);
1716 res.push(htlc_success_tx);
1719 watch_outputs.push(commitment_tx.output[transaction_output_index as usize].clone());
1720 } else { panic!("Should have sigs for non-dust local tx outputs!") }
1724 (res, watch_outputs, broadcasted_local_revokable_script)
1727 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1728 /// revoked using data in local_claimable_outpoints.
1729 /// Should not be used if check_spend_revoked_transaction succeeds.
1730 fn check_spend_local_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
1731 let commitment_txid = tx.txid();
1732 let mut local_txn = Vec::new();
1733 let mut watch_outputs = Vec::new();
1735 macro_rules! wait_threshold_conf {
1736 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1737 log_trace!(self, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1738 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1739 hash_map::Entry::Occupied(mut entry) => {
1740 let e = entry.get_mut();
1741 e.retain(|ref event| {
1743 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1744 return htlc_update.0 != $source
1749 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1751 hash_map::Entry::Vacant(entry) => {
1752 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1758 macro_rules! append_onchain_update {
1759 ($updates: expr) => {
1760 local_txn.append(&mut $updates.0);
1761 watch_outputs.append(&mut $updates.1);
1762 self.broadcasted_local_revokable_script = $updates.2;
1766 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1767 let mut is_local_tx = false;
1769 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1770 if local_tx.txid == commitment_txid {
1772 log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1773 let mut res = self.broadcast_by_local_state(tx, local_tx);
1774 append_onchain_update!(res);
1777 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1778 if local_tx.txid == commitment_txid {
1780 log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1781 let mut res = self.broadcast_by_local_state(tx, local_tx);
1782 append_onchain_update!(res);
1786 macro_rules! fail_dust_htlcs_after_threshold_conf {
1787 ($local_tx: expr) => {
1788 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1789 if htlc.transaction_output_index.is_none() {
1790 if let &Some(ref source) = source {
1791 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1799 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1800 fail_dust_htlcs_after_threshold_conf!(local_tx);
1802 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1803 fail_dust_htlcs_after_threshold_conf!(local_tx);
1807 (local_txn, (commitment_txid, watch_outputs))
1810 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1811 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1812 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1813 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1814 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1815 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1816 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1817 /// out-of-band the other node operator to coordinate with him if option is available to you.
1818 /// In any-case, choice is up to the user.
1819 pub fn get_latest_local_commitment_txn(&mut self) -> Vec<Transaction> {
1820 log_trace!(self, "Getting signed latest local commitment transaction!");
1821 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(self.channel_value_satoshis.unwrap()) {
1822 let txid = commitment_tx.txid();
1823 let mut res = vec![commitment_tx];
1824 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1825 for htlc in local_tx.htlc_outputs.iter() {
1826 if let Some(htlc_index) = htlc.0.transaction_output_index {
1827 let preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(*preimage) } else { None };
1828 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(txid, htlc_index, preimage) {
1833 // 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.
1834 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1841 /// Unsafe test-only version of get_latest_local_commitment_txn used by our test framework
1842 /// to bypass LocalCommitmentTransaction state update lockdown after signature and generate
1843 /// revoked commitment transaction.
1845 pub fn unsafe_get_latest_local_commitment_txn(&mut self) -> Vec<Transaction> {
1846 log_trace!(self, "Getting signed copy of latest local commitment transaction!");
1847 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_local_tx(self.channel_value_satoshis.unwrap()) {
1848 let txid = commitment_tx.txid();
1849 let mut res = vec![commitment_tx];
1850 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1851 for htlc in local_tx.htlc_outputs.iter() {
1852 if let Some(htlc_index) = htlc.0.transaction_output_index {
1853 let preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(*preimage) } else { None };
1854 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(txid, htlc_index, preimage) {
1865 /// Called by SimpleManyChannelMonitor::block_connected, which implements
1866 /// ChainListener::block_connected.
1867 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
1868 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
1870 fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: B, fee_estimator: F)-> Vec<(Sha256dHash, Vec<TxOut>)>
1871 where B::Target: BroadcasterInterface,
1872 F::Target: FeeEstimator
1874 for tx in txn_matched {
1875 let mut output_val = 0;
1876 for out in tx.output.iter() {
1877 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1878 output_val += out.value;
1879 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1883 log_trace!(self, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1884 let mut watch_outputs = Vec::new();
1885 let mut claimable_outpoints = Vec::new();
1886 for tx in txn_matched {
1887 if tx.input.len() == 1 {
1888 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1889 // commitment transactions and HTLC transactions will all only ever have one input,
1890 // which is an easy way to filter out any potential non-matching txn for lazy
1892 let prevout = &tx.input[0].previous_output;
1893 let funding_txo = self.onchain_detection.funding_info.clone();
1894 if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) {
1895 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1896 let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height);
1897 if !new_outputs.1.is_empty() {
1898 watch_outputs.push(new_outputs);
1900 if new_outpoints.is_empty() {
1901 let (local_txn, new_outputs) = self.check_spend_local_transaction(&tx, height);
1902 for tx in local_txn.iter() {
1903 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
1904 broadcaster.broadcast_transaction(tx);
1906 if !new_outputs.1.is_empty() {
1907 watch_outputs.push(new_outputs);
1910 claimable_outpoints.append(&mut new_outpoints);
1913 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1914 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height);
1915 claimable_outpoints.append(&mut new_outpoints);
1916 if let Some(new_outputs) = new_outputs_option {
1917 watch_outputs.push(new_outputs);
1922 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1923 // can also be resolved in a few other ways which can have more than one output. Thus,
1924 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1925 self.is_resolving_htlc_output(&tx, height);
1927 self.is_paying_spendable_output(&tx, height);
1929 let should_broadcast = if let Some(_) = self.current_local_signed_commitment_tx {
1930 self.would_broadcast_at_height(height)
1932 if should_broadcast {
1933 claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.onchain_detection.funding_info.as_ref().unwrap().0.txid.clone(), vout: self.onchain_detection.funding_info.as_ref().unwrap().0.index as u32 }, witness_data: InputMaterial::Funding { channel_value: self.channel_value_satoshis.unwrap() }});
1935 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1936 if should_broadcast {
1937 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_local_tx(self.channel_value_satoshis.unwrap()) {
1938 let (txs, new_outputs, _) = self.broadcast_by_local_state(&commitment_tx, cur_local_tx);
1939 if !new_outputs.is_empty() {
1940 watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
1943 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
1944 broadcaster.broadcast_transaction(&tx);
1949 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1952 OnchainEvent::HTLCUpdate { htlc_update } => {
1953 log_trace!(self, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1954 self.pending_htlcs_updated.push(HTLCUpdate {
1955 payment_hash: htlc_update.1,
1956 payment_preimage: None,
1957 source: htlc_update.0,
1960 OnchainEvent::MaturingOutput { descriptor } => {
1961 log_trace!(self, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1962 self.pending_events.push(events::Event::SpendableOutputs {
1963 outputs: vec![descriptor]
1969 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator);
1971 self.last_block_hash = block_hash.clone();
1972 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
1973 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
1979 fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, block_hash: &Sha256dHash, broadcaster: B, fee_estimator: F)
1980 where B::Target: BroadcasterInterface,
1981 F::Target: FeeEstimator
1983 log_trace!(self, "Block {} at height {} disconnected", block_hash, height);
1984 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1986 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1987 //- maturing spendable output has transaction paying us has been disconnected
1990 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator);
1992 self.last_block_hash = block_hash.clone();
1995 pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
1996 // We need to consider all HTLCs which are:
1997 // * in any unrevoked remote commitment transaction, as they could broadcast said
1998 // transactions and we'd end up in a race, or
1999 // * are in our latest local commitment transaction, as this is the thing we will
2000 // broadcast if we go on-chain.
2001 // Note that we consider HTLCs which were below dust threshold here - while they don't
2002 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2003 // to the source, and if we don't fail the channel we will have to ensure that the next
2004 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2005 // easier to just fail the channel as this case should be rare enough anyway.
2006 macro_rules! scan_commitment {
2007 ($htlcs: expr, $local_tx: expr) => {
2008 for ref htlc in $htlcs {
2009 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2010 // chain with enough room to claim the HTLC without our counterparty being able to
2011 // time out the HTLC first.
2012 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2013 // concern is being able to claim the corresponding inbound HTLC (on another
2014 // channel) before it expires. In fact, we don't even really care if our
2015 // counterparty here claims such an outbound HTLC after it expired as long as we
2016 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2017 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2018 // we give ourselves a few blocks of headroom after expiration before going
2019 // on-chain for an expired HTLC.
2020 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2021 // from us until we've reached the point where we go on-chain with the
2022 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2023 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2024 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2025 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2026 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2027 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2028 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2029 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2030 // The final, above, condition is checked for statically in channelmanager
2031 // with CHECK_CLTV_EXPIRY_SANITY_2.
2032 let htlc_outbound = $local_tx == htlc.offered;
2033 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2034 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2035 log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2042 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
2043 scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2046 if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
2047 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2048 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2051 if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
2052 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2053 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2060 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2061 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2062 fn is_resolving_htlc_output(&mut self, tx: &Transaction, height: u32) {
2063 'outer_loop: for input in &tx.input {
2064 let mut payment_data = None;
2065 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2066 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2067 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2068 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2070 macro_rules! log_claim {
2071 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2072 // We found the output in question, but aren't failing it backwards
2073 // as we have no corresponding source and no valid remote commitment txid
2074 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2075 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2076 let outbound_htlc = $local_tx == $htlc.offered;
2077 if ($local_tx && revocation_sig_claim) ||
2078 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2079 log_error!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2080 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2081 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2082 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2084 log_info!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2085 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2086 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2087 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2092 macro_rules! check_htlc_valid_remote {
2093 ($remote_txid: expr, $htlc_output: expr) => {
2094 if let Some(txid) = $remote_txid {
2095 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2096 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2097 if let &Some(ref source) = pending_source {
2098 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2099 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2108 macro_rules! scan_commitment {
2109 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2110 for (ref htlc_output, source_option) in $htlcs {
2111 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2112 if let Some(ref source) = source_option {
2113 log_claim!($tx_info, $local_tx, htlc_output, true);
2114 // We have a resolution of an HTLC either from one of our latest
2115 // local commitment transactions or an unrevoked remote commitment
2116 // transaction. This implies we either learned a preimage, the HTLC
2117 // has timed out, or we screwed up. In any case, we should now
2118 // resolve the source HTLC with the original sender.
2119 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2120 } else if !$local_tx {
2121 check_htlc_valid_remote!(self.onchain_detection.current_remote_commitment_txid, htlc_output);
2122 if payment_data.is_none() {
2123 check_htlc_valid_remote!(self.onchain_detection.prev_remote_commitment_txid, htlc_output);
2126 if payment_data.is_none() {
2127 log_claim!($tx_info, $local_tx, htlc_output, false);
2128 continue 'outer_loop;
2135 if let Some(ref current_local_signed_commitment_tx) = self.current_local_signed_commitment_tx {
2136 if input.previous_output.txid == current_local_signed_commitment_tx.txid {
2137 scan_commitment!(current_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2138 "our latest local commitment tx", true);
2141 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2142 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2143 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2144 "our previous local commitment tx", true);
2147 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2148 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2149 "remote commitment tx", false);
2152 // Check that scan_commitment, above, decided there is some source worth relaying an
2153 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2154 if let Some((source, payment_hash)) = payment_data {
2155 let mut payment_preimage = PaymentPreimage([0; 32]);
2156 if accepted_preimage_claim {
2157 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2158 payment_preimage.0.copy_from_slice(&input.witness[3]);
2159 self.pending_htlcs_updated.push(HTLCUpdate {
2161 payment_preimage: Some(payment_preimage),
2165 } else if offered_preimage_claim {
2166 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2167 payment_preimage.0.copy_from_slice(&input.witness[1]);
2168 self.pending_htlcs_updated.push(HTLCUpdate {
2170 payment_preimage: Some(payment_preimage),
2175 log_info!(self, "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);
2176 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2177 hash_map::Entry::Occupied(mut entry) => {
2178 let e = entry.get_mut();
2179 e.retain(|ref event| {
2181 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2182 return htlc_update.0 != source
2187 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2189 hash_map::Entry::Vacant(entry) => {
2190 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2198 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2199 fn is_paying_spendable_output(&mut self, tx: &Transaction, height: u32) {
2200 let mut spendable_output = None;
2201 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2202 if outp.script_pubkey == self.destination_script {
2203 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2204 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2205 output: outp.clone(),
2208 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2209 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2210 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2211 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2212 key: broadcasted_local_revokable_script.1,
2213 witness_script: broadcasted_local_revokable_script.2.clone(),
2214 to_self_delay: self.their_to_self_delay.unwrap(),
2215 output: outp.clone(),
2219 } else if let Some(ref broadcasted_remote_payment_script) = self.broadcasted_remote_payment_script {
2220 if broadcasted_remote_payment_script.0 == outp.script_pubkey {
2221 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WPKH {
2222 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2223 key: broadcasted_remote_payment_script.1,
2224 output: outp.clone(),
2228 } else if outp.script_pubkey == self.shutdown_script {
2229 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2230 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2231 output: outp.clone(),
2235 if let Some(spendable_output) = spendable_output {
2236 log_trace!(self, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2237 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2238 hash_map::Entry::Occupied(mut entry) => {
2239 let e = entry.get_mut();
2240 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2242 hash_map::Entry::Vacant(entry) => {
2243 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2250 const MAX_ALLOC_SIZE: usize = 64*1024;
2252 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dHash, ChannelMonitor<ChanSigner>) {
2253 fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
2254 macro_rules! unwrap_obj {
2258 Err(_) => return Err(DecodeError::InvalidValue),
2263 let _ver: u8 = Readable::read(reader)?;
2264 let min_ver: u8 = Readable::read(reader)?;
2265 if min_ver > SERIALIZATION_VERSION {
2266 return Err(DecodeError::UnknownVersion);
2269 let latest_update_id: u64 = Readable::read(reader)?;
2270 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2272 let destination_script = Readable::read(reader)?;
2273 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2275 let revokable_address = Readable::read(reader)?;
2276 let local_delayedkey = Readable::read(reader)?;
2277 let revokable_script = Readable::read(reader)?;
2278 Some((revokable_address, local_delayedkey, revokable_script))
2281 _ => return Err(DecodeError::InvalidValue),
2283 let broadcasted_remote_payment_script = match <u8 as Readable>::read(reader)? {
2285 let payment_address = Readable::read(reader)?;
2286 let payment_key = Readable::read(reader)?;
2287 Some((payment_address, payment_key))
2290 _ => return Err(DecodeError::InvalidValue),
2292 let shutdown_script = Readable::read(reader)?;
2294 let onchain_detection = {
2295 let keys = Readable::read(reader)?;
2296 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2297 // barely-init'd ChannelMonitors that we can't do anything with.
2298 let outpoint = OutPoint {
2299 txid: Readable::read(reader)?,
2300 index: Readable::read(reader)?,
2302 let funding_info = Some((outpoint, Readable::read(reader)?));
2303 let current_remote_commitment_txid = Readable::read(reader)?;
2304 let prev_remote_commitment_txid = Readable::read(reader)?;
2308 current_remote_commitment_txid,
2309 prev_remote_commitment_txid,
2313 let their_htlc_base_key = Some(Readable::read(reader)?);
2314 let their_delayed_payment_base_key = Some(Readable::read(reader)?);
2315 let funding_redeemscript = Some(Readable::read(reader)?);
2316 let channel_value_satoshis = Some(Readable::read(reader)?);
2318 let their_cur_revocation_points = {
2319 let first_idx = <U48 as Readable>::read(reader)?.0;
2323 let first_point = Readable::read(reader)?;
2324 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2325 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2326 Some((first_idx, first_point, None))
2328 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2333 let our_to_self_delay: u16 = Readable::read(reader)?;
2334 let their_to_self_delay: Option<u16> = Some(Readable::read(reader)?);
2336 let commitment_secrets = Readable::read(reader)?;
2338 macro_rules! read_htlc_in_commitment {
2341 let offered: bool = Readable::read(reader)?;
2342 let amount_msat: u64 = Readable::read(reader)?;
2343 let cltv_expiry: u32 = Readable::read(reader)?;
2344 let payment_hash: PaymentHash = Readable::read(reader)?;
2345 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2347 HTLCOutputInCommitment {
2348 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2354 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2355 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2356 for _ in 0..remote_claimable_outpoints_len {
2357 let txid: Sha256dHash = Readable::read(reader)?;
2358 let htlcs_count: u64 = Readable::read(reader)?;
2359 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2360 for _ in 0..htlcs_count {
2361 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2363 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2364 return Err(DecodeError::InvalidValue);
2368 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2369 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2370 for _ in 0..remote_commitment_txn_on_chain_len {
2371 let txid: Sha256dHash = Readable::read(reader)?;
2372 let commitment_number = <U48 as Readable>::read(reader)?.0;
2373 let outputs_count = <u64 as Readable>::read(reader)?;
2374 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2375 for _ in 0..outputs_count {
2376 outputs.push(Readable::read(reader)?);
2378 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2379 return Err(DecodeError::InvalidValue);
2383 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2384 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2385 for _ in 0..remote_hash_commitment_number_len {
2386 let payment_hash: PaymentHash = Readable::read(reader)?;
2387 let commitment_number = <U48 as Readable>::read(reader)?.0;
2388 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2389 return Err(DecodeError::InvalidValue);
2393 macro_rules! read_local_tx {
2396 let tx = <LocalCommitmentTransaction as Readable>::read(reader)?;
2397 let revocation_key = Readable::read(reader)?;
2398 let a_htlc_key = Readable::read(reader)?;
2399 let b_htlc_key = Readable::read(reader)?;
2400 let delayed_payment_key = Readable::read(reader)?;
2401 let per_commitment_point = Readable::read(reader)?;
2402 let feerate_per_kw: u64 = Readable::read(reader)?;
2404 let htlcs_len: u64 = Readable::read(reader)?;
2405 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2406 for _ in 0..htlcs_len {
2407 let htlc = read_htlc_in_commitment!();
2408 let sigs = match <u8 as Readable>::read(reader)? {
2410 1 => Some(Readable::read(reader)?),
2411 _ => return Err(DecodeError::InvalidValue),
2413 htlcs.push((htlc, sigs, Readable::read(reader)?));
2419 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2426 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2429 Some(read_local_tx!())
2431 _ => return Err(DecodeError::InvalidValue),
2434 let current_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2437 Some(read_local_tx!())
2439 _ => return Err(DecodeError::InvalidValue),
2442 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2443 let current_local_commitment_number = <U48 as Readable>::read(reader)?.0;
2445 let payment_preimages_len: u64 = Readable::read(reader)?;
2446 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2447 for _ in 0..payment_preimages_len {
2448 let preimage: PaymentPreimage = Readable::read(reader)?;
2449 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2450 if let Some(_) = payment_preimages.insert(hash, preimage) {
2451 return Err(DecodeError::InvalidValue);
2455 let pending_htlcs_updated_len: u64 = Readable::read(reader)?;
2456 let mut pending_htlcs_updated = Vec::with_capacity(cmp::min(pending_htlcs_updated_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2457 for _ in 0..pending_htlcs_updated_len {
2458 pending_htlcs_updated.push(Readable::read(reader)?);
2461 let pending_events_len: u64 = Readable::read(reader)?;
2462 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<events::Event>()));
2463 for _ in 0..pending_events_len {
2464 if let Some(event) = MaybeReadable::read(reader)? {
2465 pending_events.push(event);
2469 let last_block_hash: Sha256dHash = Readable::read(reader)?;
2471 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2472 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2473 for _ in 0..waiting_threshold_conf_len {
2474 let height_target = Readable::read(reader)?;
2475 let events_len: u64 = Readable::read(reader)?;
2476 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2477 for _ in 0..events_len {
2478 let ev = match <u8 as Readable>::read(reader)? {
2480 let htlc_source = Readable::read(reader)?;
2481 let hash = Readable::read(reader)?;
2482 OnchainEvent::HTLCUpdate {
2483 htlc_update: (htlc_source, hash)
2487 let descriptor = Readable::read(reader)?;
2488 OnchainEvent::MaturingOutput {
2492 _ => return Err(DecodeError::InvalidValue),
2496 onchain_events_waiting_threshold_conf.insert(height_target, events);
2499 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2500 let mut outputs_to_watch = HashMap::with_capacity(cmp::min(outputs_to_watch_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<Sha256dHash>() + mem::size_of::<Vec<Script>>())));
2501 for _ in 0..outputs_to_watch_len {
2502 let txid = Readable::read(reader)?;
2503 let outputs_len: u64 = Readable::read(reader)?;
2504 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2505 for _ in 0..outputs_len {
2506 outputs.push(Readable::read(reader)?);
2508 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2509 return Err(DecodeError::InvalidValue);
2512 let onchain_tx_handler = ReadableArgs::read(reader, logger.clone())?;
2514 Ok((last_block_hash.clone(), ChannelMonitor {
2516 commitment_transaction_number_obscure_factor,
2519 broadcasted_local_revokable_script,
2520 broadcasted_remote_payment_script,
2524 their_htlc_base_key,
2525 their_delayed_payment_base_key,
2526 funding_redeemscript,
2527 channel_value_satoshis,
2528 their_cur_revocation_points,
2531 their_to_self_delay,
2534 remote_claimable_outpoints,
2535 remote_commitment_txn_on_chain,
2536 remote_hash_commitment_number,
2538 prev_local_signed_commitment_tx,
2539 current_local_signed_commitment_tx,
2540 current_remote_commitment_number,
2541 current_local_commitment_number,
2544 pending_htlcs_updated,
2547 onchain_events_waiting_threshold_conf,
2553 secp_ctx: Secp256k1::new(),
2561 use bitcoin::blockdata::script::{Script, Builder};
2562 use bitcoin::blockdata::opcodes;
2563 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2564 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2565 use bitcoin::util::bip143;
2566 use bitcoin_hashes::Hash;
2567 use bitcoin_hashes::sha256::Hash as Sha256;
2568 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
2569 use bitcoin_hashes::hex::FromHex;
2571 use chain::transaction::OutPoint;
2572 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2573 use ln::channelmonitor::ChannelMonitor;
2574 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2576 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys, LocalCommitmentTransaction};
2577 use util::test_utils::TestLogger;
2578 use secp256k1::key::{SecretKey,PublicKey};
2579 use secp256k1::Secp256k1;
2580 use rand::{thread_rng,Rng};
2582 use chain::keysinterface::InMemoryChannelKeys;
2585 fn test_prune_preimages() {
2586 let secp_ctx = Secp256k1::new();
2587 let logger = Arc::new(TestLogger::new());
2589 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2590 macro_rules! dummy_keys {
2594 per_commitment_point: dummy_key.clone(),
2595 revocation_key: dummy_key.clone(),
2596 a_htlc_key: dummy_key.clone(),
2597 b_htlc_key: dummy_key.clone(),
2598 a_delayed_payment_key: dummy_key.clone(),
2599 b_payment_key: dummy_key.clone(),
2604 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2606 let mut preimages = Vec::new();
2608 let mut rng = thread_rng();
2610 let mut preimage = PaymentPreimage([0; 32]);
2611 rng.fill_bytes(&mut preimage.0[..]);
2612 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2613 preimages.push((preimage, hash));
2617 macro_rules! preimages_slice_to_htlc_outputs {
2618 ($preimages_slice: expr) => {
2620 let mut res = Vec::new();
2621 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2622 res.push((HTLCOutputInCommitment {
2626 payment_hash: preimage.1.clone(),
2627 transaction_output_index: Some(idx as u32),
2634 macro_rules! preimages_to_local_htlcs {
2635 ($preimages_slice: expr) => {
2637 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2638 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2644 macro_rules! test_preimages_exist {
2645 ($preimages_slice: expr, $monitor: expr) => {
2646 for preimage in $preimages_slice {
2647 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2652 let keys = InMemoryChannelKeys::new(
2654 SecretKey::from_slice(&[41; 32]).unwrap(),
2655 SecretKey::from_slice(&[41; 32]).unwrap(),
2656 SecretKey::from_slice(&[41; 32]).unwrap(),
2657 SecretKey::from_slice(&[41; 32]).unwrap(),
2658 SecretKey::from_slice(&[41; 32]).unwrap(),
2663 // Prune with one old state and a local commitment tx holding a few overlaps with the
2665 let mut monitor = ChannelMonitor::new(keys,
2666 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2667 (OutPoint { txid: Sha256dHash::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2668 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2669 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2670 0, Script::new(), 46, 0, logger.clone());
2672 monitor.their_to_self_delay = Some(10);
2674 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2675 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
2676 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
2677 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
2678 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key);
2679 for &(ref preimage, ref hash) in preimages.iter() {
2680 monitor.provide_payment_preimage(hash, preimage);
2683 // Now provide a secret, pruning preimages 10-15
2684 let mut secret = [0; 32];
2685 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2686 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2687 assert_eq!(monitor.payment_preimages.len(), 15);
2688 test_preimages_exist!(&preimages[0..10], monitor);
2689 test_preimages_exist!(&preimages[15..20], monitor);
2691 // Now provide a further secret, pruning preimages 15-17
2692 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2693 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2694 assert_eq!(monitor.payment_preimages.len(), 13);
2695 test_preimages_exist!(&preimages[0..10], monitor);
2696 test_preimages_exist!(&preimages[17..20], monitor);
2698 // Now update local commitment tx info, pruning only element 18 as we still care about the
2699 // previous commitment tx's preimages too
2700 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2701 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2702 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2703 assert_eq!(monitor.payment_preimages.len(), 12);
2704 test_preimages_exist!(&preimages[0..10], monitor);
2705 test_preimages_exist!(&preimages[18..20], monitor);
2707 // But if we do it again, we'll prune 5-10
2708 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2709 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2710 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2711 assert_eq!(monitor.payment_preimages.len(), 5);
2712 test_preimages_exist!(&preimages[0..5], monitor);
2716 fn test_claim_txn_weight_computation() {
2717 // We test Claim txn weight, knowing that we want expected weigth and
2718 // not actual case to avoid sigs and time-lock delays hell variances.
2720 let secp_ctx = Secp256k1::new();
2721 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2722 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2723 let mut sum_actual_sigs = 0;
2725 macro_rules! sign_input {
2726 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2727 let htlc = HTLCOutputInCommitment {
2728 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2730 cltv_expiry: 2 << 16,
2731 payment_hash: PaymentHash([1; 32]),
2732 transaction_output_index: Some($idx),
2734 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2735 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2736 let sig = secp_ctx.sign(&sighash, &privkey);
2737 $input.witness.push(sig.serialize_der().to_vec());
2738 $input.witness[0].push(SigHashType::All as u8);
2739 sum_actual_sigs += $input.witness[0].len();
2740 if *$input_type == InputDescriptors::RevokedOutput {
2741 $input.witness.push(vec!(1));
2742 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2743 $input.witness.push(pubkey.clone().serialize().to_vec());
2744 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2745 $input.witness.push(vec![0]);
2747 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2749 $input.witness.push(redeem_script.into_bytes());
2750 println!("witness[0] {}", $input.witness[0].len());
2751 println!("witness[1] {}", $input.witness[1].len());
2752 println!("witness[2] {}", $input.witness[2].len());
2756 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2757 let txid = Sha256dHash::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2759 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2760 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2762 claim_tx.input.push(TxIn {
2763 previous_output: BitcoinOutPoint {
2767 script_sig: Script::new(),
2768 sequence: 0xfffffffd,
2769 witness: Vec::new(),
2772 claim_tx.output.push(TxOut {
2773 script_pubkey: script_pubkey.clone(),
2776 let base_weight = claim_tx.get_weight();
2777 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2778 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2779 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2780 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2782 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2784 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2785 claim_tx.input.clear();
2786 sum_actual_sigs = 0;
2788 claim_tx.input.push(TxIn {
2789 previous_output: BitcoinOutPoint {
2793 script_sig: Script::new(),
2794 sequence: 0xfffffffd,
2795 witness: Vec::new(),
2798 let base_weight = claim_tx.get_weight();
2799 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2800 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2801 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2802 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2804 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));
2806 // Justice tx with 1 revoked HTLC-Success tx output
2807 claim_tx.input.clear();
2808 sum_actual_sigs = 0;
2809 claim_tx.input.push(TxIn {
2810 previous_output: BitcoinOutPoint {
2814 script_sig: Script::new(),
2815 sequence: 0xfffffffd,
2816 witness: Vec::new(),
2818 let base_weight = claim_tx.get_weight();
2819 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2820 let inputs_des = vec![InputDescriptors::RevokedOutput];
2821 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2822 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2824 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));
2827 // Further testing is done in the ChannelManager integration tests.