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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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.key_storage {
294 Storage::Local { ref funding_info, .. } => {
297 return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !"));
299 &Some((ref outpoint, ref script)) => {
300 log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..]));
301 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
302 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
306 Storage::Watchtower { .. } => {
307 self.chain_monitor.watch_all_txn();
310 for (txid, outputs) in monitor.get_outputs_to_watch().iter() {
311 for (idx, script) in outputs.iter().enumerate() {
312 self.chain_monitor.install_watch_outpoint((*txid, idx as u32), script);
315 entry.insert(monitor);
319 /// Updates the monitor which monitors the channel referred to by the given key.
320 pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
321 let mut monitors = self.monitors.lock().unwrap();
322 match monitors.get_mut(&key) {
323 Some(orig_monitor) => {
324 log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor.key_storage));
325 orig_monitor.update_monitor(update, &self.broadcaster)
327 None => Err(MonitorUpdateError("No such monitor registered"))
332 impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send> ManyChannelMonitor<ChanSigner> for SimpleManyChannelMonitor<OutPoint, ChanSigner, T, F>
333 where T::Target: BroadcasterInterface,
334 F::Target: FeeEstimator
336 fn add_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
337 match self.add_monitor_by_key(funding_txo, monitor) {
339 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
343 fn update_monitor(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
344 match self.update_monitor_by_key(funding_txo, update) {
346 Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
350 fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {
351 let mut pending_htlcs_updated = Vec::new();
352 for chan in self.monitors.lock().unwrap().values_mut() {
353 pending_htlcs_updated.append(&mut chan.get_and_clear_pending_htlcs_updated());
355 pending_htlcs_updated
359 impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref> events::EventsProvider for SimpleManyChannelMonitor<Key, ChanSigner, T, F>
360 where T::Target: BroadcasterInterface,
361 F::Target: FeeEstimator
363 fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
364 let mut pending_events = Vec::new();
365 for chan in self.monitors.lock().unwrap().values_mut() {
366 pending_events.append(&mut chan.get_and_clear_pending_events());
372 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
373 /// instead claiming it in its own individual transaction.
374 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
375 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
376 /// HTLC-Success transaction.
377 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
378 /// transaction confirmed (and we use it in a few more, equivalent, places).
379 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
380 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
381 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
382 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
383 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
384 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
385 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
386 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
387 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
388 /// accurate block height.
389 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
390 /// with at worst this delay, so we are not only using this value as a mercy for them but also
391 /// us as a safeguard to delay with enough time.
392 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
393 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
394 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
395 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
396 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
397 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
398 /// keeping bumping another claim tx to solve the outpoint.
399 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
401 enum Storage<ChanSigner: ChannelKeys> {
404 funding_key: SecretKey,
405 revocation_base_key: SecretKey,
406 htlc_base_key: SecretKey,
407 delayed_payment_base_key: SecretKey,
408 payment_base_key: SecretKey,
409 shutdown_pubkey: PublicKey,
410 funding_info: Option<(OutPoint, Script)>,
411 current_remote_commitment_txid: Option<Sha256dHash>,
412 prev_remote_commitment_txid: Option<Sha256dHash>,
415 revocation_base_key: PublicKey,
416 htlc_base_key: PublicKey,
420 #[cfg(any(test, feature = "fuzztarget"))]
421 impl<ChanSigner: ChannelKeys> PartialEq for Storage<ChanSigner> {
422 fn eq(&self, other: &Self) -> bool {
424 Storage::Local { ref keys, .. } => {
427 Storage::Local { ref keys, .. } => keys.pubkeys() == k.pubkeys(),
428 Storage::Watchtower { .. } => false,
431 Storage::Watchtower {ref revocation_base_key, ref htlc_base_key} => {
432 let (rbk, hbk) = (revocation_base_key, htlc_base_key);
434 Storage::Local { .. } => false,
435 Storage::Watchtower {ref revocation_base_key, ref htlc_base_key} =>
436 revocation_base_key == rbk && htlc_base_key == hbk,
443 #[derive(Clone, PartialEq)]
444 struct LocalSignedTx {
445 /// txid of the transaction in tx, just used to make comparison faster
447 tx: LocalCommitmentTransaction,
448 revocation_key: PublicKey,
449 a_htlc_key: PublicKey,
450 b_htlc_key: PublicKey,
451 delayed_payment_key: PublicKey,
452 per_commitment_point: PublicKey,
454 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
457 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
458 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
459 /// a new bumped one in case of lenghty confirmation delay
460 #[derive(Clone, PartialEq)]
461 pub(crate) enum InputMaterial {
463 witness_script: Script,
464 pubkey: Option<PublicKey>,
470 witness_script: Script,
472 preimage: Option<PaymentPreimage>,
477 witness_script: Script,
478 sigs: (Signature, Signature),
479 preimage: Option<PaymentPreimage>,
484 impl Writeable for InputMaterial {
485 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
487 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount} => {
488 writer.write_all(&[0; 1])?;
489 witness_script.write(writer)?;
490 pubkey.write(writer)?;
491 writer.write_all(&key[..])?;
492 is_htlc.write(writer)?;
493 writer.write_all(&byte_utils::be64_to_array(*amount))?;
495 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
496 writer.write_all(&[1; 1])?;
497 witness_script.write(writer)?;
499 preimage.write(writer)?;
500 writer.write_all(&byte_utils::be64_to_array(*amount))?;
501 writer.write_all(&byte_utils::be32_to_array(*locktime))?;
503 &InputMaterial::LocalHTLC { ref witness_script, ref sigs, ref preimage, ref amount } => {
504 writer.write_all(&[2; 1])?;
505 witness_script.write(writer)?;
506 sigs.0.write(writer)?;
507 sigs.1.write(writer)?;
508 preimage.write(writer)?;
509 writer.write_all(&byte_utils::be64_to_array(*amount))?;
516 impl Readable for InputMaterial {
517 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
518 let input_material = match <u8 as Readable>::read(reader)? {
520 let witness_script = Readable::read(reader)?;
521 let pubkey = Readable::read(reader)?;
522 let key = Readable::read(reader)?;
523 let is_htlc = Readable::read(reader)?;
524 let amount = Readable::read(reader)?;
525 InputMaterial::Revoked {
534 let witness_script = Readable::read(reader)?;
535 let key = Readable::read(reader)?;
536 let preimage = Readable::read(reader)?;
537 let amount = Readable::read(reader)?;
538 let locktime = Readable::read(reader)?;
539 InputMaterial::RemoteHTLC {
548 let witness_script = Readable::read(reader)?;
549 let their_sig = Readable::read(reader)?;
550 let our_sig = Readable::read(reader)?;
551 let preimage = Readable::read(reader)?;
552 let amount = Readable::read(reader)?;
553 InputMaterial::LocalHTLC {
555 sigs: (their_sig, our_sig),
560 _ => return Err(DecodeError::InvalidValue),
566 /// ClaimRequest is a descriptor structure to communicate between detection
567 /// and reaction module. They are generated by ChannelMonitor while parsing
568 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
569 /// is responsible for opportunistic aggregation, selecting and enforcing
570 /// bumping logic, building and signing transactions.
571 pub(crate) struct ClaimRequest {
572 // Block height before which claiming is exclusive to one party,
573 // after reaching it, claiming may be contentious.
574 pub(crate) absolute_timelock: u32,
575 // Timeout tx must have nLocktime set which means aggregating multiple
576 // ones must take the higher nLocktime among them to satisfy all of them.
577 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
578 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
579 // Do simplify we mark them as non-aggregable.
580 pub(crate) aggregable: bool,
581 // Basic bitcoin outpoint (txid, vout)
582 pub(crate) outpoint: BitcoinOutPoint,
583 // Following outpoint type, set of data needed to generate transaction digest
584 // and satisfy witness program.
585 pub(crate) witness_data: InputMaterial
588 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
589 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
590 #[derive(Clone, PartialEq)]
592 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
593 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
594 /// only win from it, so it's never an OnchainEvent
596 htlc_update: (HTLCSource, PaymentHash),
600 const SERIALIZATION_VERSION: u8 = 1;
601 const MIN_SERIALIZATION_VERSION: u8 = 1;
603 #[cfg_attr(test, derive(PartialEq))]
605 pub(super) enum ChannelMonitorUpdateStep {
606 LatestLocalCommitmentTXInfo {
607 // TODO: We really need to not be generating a fully-signed transaction in Channel and
608 // passing it here, we need to hold off so that the ChanSigner can enforce a
609 // only-sign-local-state-for-broadcast once invariant:
610 commitment_tx: LocalCommitmentTransaction,
611 local_keys: chan_utils::TxCreationKeys,
613 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
615 LatestRemoteCommitmentTXInfo {
616 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
617 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
618 commitment_number: u64,
619 their_revocation_point: PublicKey,
622 payment_preimage: PaymentPreimage,
628 /// Indicates our channel is likely a stale version, we're closing, but this update should
629 /// allow us to spend what is ours if our counterparty broadcasts their latest state.
630 RescueRemoteCommitmentTXInfo {
631 their_current_per_commitment_point: PublicKey,
633 /// Used to indicate that the no future updates will occur, and likely that the latest local
634 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
636 /// If set to false, we shouldn't broadcast the latest local commitment transaction as we
637 /// think we've fallen behind!
638 should_broadcast: bool,
642 impl Writeable for ChannelMonitorUpdateStep {
643 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
645 &ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { ref commitment_tx, ref local_keys, ref feerate_per_kw, ref htlc_outputs } => {
647 commitment_tx.write(w)?;
648 local_keys.write(w)?;
649 feerate_per_kw.write(w)?;
650 (htlc_outputs.len() as u64).write(w)?;
651 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
657 &ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
659 unsigned_commitment_tx.write(w)?;
660 commitment_number.write(w)?;
661 their_revocation_point.write(w)?;
662 (htlc_outputs.len() as u64).write(w)?;
663 for &(ref output, ref source) in htlc_outputs.iter() {
665 source.as_ref().map(|b| b.as_ref()).write(w)?;
668 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
670 payment_preimage.write(w)?;
672 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
677 &ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { ref their_current_per_commitment_point } => {
679 their_current_per_commitment_point.write(w)?;
681 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
683 should_broadcast.write(w)?;
689 impl Readable for ChannelMonitorUpdateStep {
690 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
691 match Readable::read(r)? {
693 Ok(ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
694 commitment_tx: Readable::read(r)?,
695 local_keys: Readable::read(r)?,
696 feerate_per_kw: Readable::read(r)?,
698 let len: u64 = Readable::read(r)?;
699 let mut res = Vec::new();
701 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
708 Ok(ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
709 unsigned_commitment_tx: Readable::read(r)?,
710 commitment_number: Readable::read(r)?,
711 their_revocation_point: Readable::read(r)?,
713 let len: u64 = Readable::read(r)?;
714 let mut res = Vec::new();
716 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
723 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
724 payment_preimage: Readable::read(r)?,
728 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
729 idx: Readable::read(r)?,
730 secret: Readable::read(r)?,
734 Ok(ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo {
735 their_current_per_commitment_point: Readable::read(r)?,
739 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
740 should_broadcast: Readable::read(r)?
743 _ => Err(DecodeError::InvalidValue),
748 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
749 /// on-chain transactions to ensure no loss of funds occurs.
751 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
752 /// information and are actively monitoring the chain.
754 /// Pending Events or updated HTLCs which have not yet been read out by
755 /// get_and_clear_pending_htlcs_updated or get_and_clear_pending_events are serialized to disk and
756 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
757 /// gotten are fully handled before re-serializing the new state.
758 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
759 latest_update_id: u64,
760 commitment_transaction_number_obscure_factor: u64,
762 destination_script: Script,
763 broadcasted_local_revokable_script: Option<(Script, SecretKey, Script)>,
765 key_storage: Storage<ChanSigner>,
766 their_htlc_base_key: Option<PublicKey>,
767 their_delayed_payment_base_key: Option<PublicKey>,
768 funding_redeemscript: Option<Script>,
769 channel_value_satoshis: Option<u64>,
770 // first is the idx of the first of the two revocation points
771 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
773 our_to_self_delay: u16,
774 their_to_self_delay: Option<u16>,
776 commitment_secrets: CounterpartyCommitmentSecrets,
777 remote_claimable_outpoints: HashMap<Sha256dHash, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
778 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
779 /// Nor can we figure out their commitment numbers without the commitment transaction they are
780 /// spending. Thus, in order to claim them via revocation key, we track all the remote
781 /// commitment transactions which we find on-chain, mapping them to the commitment number which
782 /// can be used to derive the revocation key and claim the transactions.
783 remote_commitment_txn_on_chain: HashMap<Sha256dHash, (u64, Vec<Script>)>,
784 /// Cache used to make pruning of payment_preimages faster.
785 /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
786 /// remote transactions (ie should remain pretty small).
787 /// Serialized to disk but should generally not be sent to Watchtowers.
788 remote_hash_commitment_number: HashMap<PaymentHash, u64>,
790 // We store two local commitment transactions to avoid any race conditions where we may update
791 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
792 // various monitors for one channel being out of sync, and us broadcasting a local
793 // transaction for which we have deleted claim information on some watchtowers.
794 prev_local_signed_commitment_tx: Option<LocalSignedTx>,
795 current_local_signed_commitment_tx: Option<LocalSignedTx>,
797 // Used just for ChannelManager to make sure it has the latest channel data during
799 current_remote_commitment_number: u64,
801 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
803 pending_htlcs_updated: Vec<HTLCUpdate>,
804 pending_events: Vec<events::Event>,
806 // Thanks to data loss protection, we may be able to claim our non-htlc funds
807 // back, this is the script we have to spend from but we need to
808 // scan every commitment transaction for that
809 to_remote_rescue: Option<(Script, SecretKey)>,
811 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
812 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
813 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
814 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
816 // If we get serialized out and re-read, we need to make sure that the chain monitoring
817 // interface knows about the TXOs that we want to be notified of spends of. We could probably
818 // be smart and derive them from the above storage fields, but its much simpler and more
819 // Obviously Correct (tm) if we just keep track of them explicitly.
820 outputs_to_watch: HashMap<Sha256dHash, Vec<Script>>,
823 pub onchain_tx_handler: OnchainTxHandler,
825 onchain_tx_handler: OnchainTxHandler,
827 // We simply modify last_block_hash in Channel's block_connected so that serialization is
828 // consistent but hopefully the users' copy handles block_connected in a consistent way.
829 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
830 // their last_block_hash from its state and not based on updated copies that didn't run through
831 // the full block_connected).
832 pub(crate) last_block_hash: Sha256dHash,
833 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
837 #[cfg(any(test, feature = "fuzztarget"))]
838 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
839 /// underlying object
840 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
841 fn eq(&self, other: &Self) -> bool {
842 if self.latest_update_id != other.latest_update_id ||
843 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
844 self.destination_script != other.destination_script ||
845 self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
846 self.key_storage != other.key_storage ||
847 self.their_htlc_base_key != other.their_htlc_base_key ||
848 self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
849 self.funding_redeemscript != other.funding_redeemscript ||
850 self.channel_value_satoshis != other.channel_value_satoshis ||
851 self.their_cur_revocation_points != other.their_cur_revocation_points ||
852 self.our_to_self_delay != other.our_to_self_delay ||
853 self.their_to_self_delay != other.their_to_self_delay ||
854 self.commitment_secrets != other.commitment_secrets ||
855 self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
856 self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
857 self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
858 self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
859 self.current_remote_commitment_number != other.current_remote_commitment_number ||
860 self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
861 self.payment_preimages != other.payment_preimages ||
862 self.pending_htlcs_updated != other.pending_htlcs_updated ||
863 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
864 self.to_remote_rescue != other.to_remote_rescue ||
865 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
866 self.outputs_to_watch != other.outputs_to_watch
875 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
876 /// Serializes into a vec, with various modes for the exposed pub fns
877 fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
878 //TODO: We still write out all the serialization here manually instead of using the fancy
879 //serialization framework we have, we should migrate things over to it.
880 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
881 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
883 self.latest_update_id.write(writer)?;
885 // Set in initial Channel-object creation, so should always be set by now:
886 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
888 self.destination_script.write(writer)?;
889 if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
890 writer.write_all(&[0; 1])?;
891 broadcasted_local_revokable_script.0.write(writer)?;
892 broadcasted_local_revokable_script.1.write(writer)?;
893 broadcasted_local_revokable_script.2.write(writer)?;
895 writer.write_all(&[1; 1])?;
898 match self.key_storage {
899 Storage::Local { ref keys, ref funding_key, ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref funding_info, ref current_remote_commitment_txid, ref prev_remote_commitment_txid } => {
900 writer.write_all(&[0; 1])?;
902 writer.write_all(&funding_key[..])?;
903 writer.write_all(&revocation_base_key[..])?;
904 writer.write_all(&htlc_base_key[..])?;
905 writer.write_all(&delayed_payment_base_key[..])?;
906 writer.write_all(&payment_base_key[..])?;
907 writer.write_all(&shutdown_pubkey.serialize())?;
909 &Some((ref outpoint, ref script)) => {
910 writer.write_all(&outpoint.txid[..])?;
911 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
912 script.write(writer)?;
915 debug_assert!(false, "Try to serialize a useless Local monitor !");
918 current_remote_commitment_txid.write(writer)?;
919 prev_remote_commitment_txid.write(writer)?;
921 Storage::Watchtower { .. } => unimplemented!(),
924 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
925 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
926 self.funding_redeemscript.as_ref().unwrap().write(writer)?;
927 self.channel_value_satoshis.unwrap().write(writer)?;
929 match self.their_cur_revocation_points {
930 Some((idx, pubkey, second_option)) => {
931 writer.write_all(&byte_utils::be48_to_array(idx))?;
932 writer.write_all(&pubkey.serialize())?;
933 match second_option {
934 Some(second_pubkey) => {
935 writer.write_all(&second_pubkey.serialize())?;
938 writer.write_all(&[0; 33])?;
943 writer.write_all(&byte_utils::be48_to_array(0))?;
947 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
948 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
950 self.commitment_secrets.write(writer)?;
952 macro_rules! serialize_htlc_in_commitment {
953 ($htlc_output: expr) => {
954 writer.write_all(&[$htlc_output.offered as u8; 1])?;
955 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
956 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
957 writer.write_all(&$htlc_output.payment_hash.0[..])?;
958 $htlc_output.transaction_output_index.write(writer)?;
962 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
963 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
964 writer.write_all(&txid[..])?;
965 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
966 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
967 serialize_htlc_in_commitment!(htlc_output);
968 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
972 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
973 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
974 writer.write_all(&txid[..])?;
975 writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
976 (txouts.len() as u64).write(writer)?;
977 for script in txouts.iter() {
978 script.write(writer)?;
982 if for_local_storage {
983 writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
984 for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
985 writer.write_all(&payment_hash.0[..])?;
986 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
989 writer.write_all(&byte_utils::be64_to_array(0))?;
992 macro_rules! serialize_local_tx {
993 ($local_tx: expr) => {
994 $local_tx.tx.write(writer)?;
995 writer.write_all(&$local_tx.revocation_key.serialize())?;
996 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
997 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
998 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
999 writer.write_all(&$local_tx.per_commitment_point.serialize())?;
1001 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
1002 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
1003 for &(ref htlc_output, ref sig, ref htlc_source) in $local_tx.htlc_outputs.iter() {
1004 serialize_htlc_in_commitment!(htlc_output);
1005 if let &Some(ref their_sig) = sig {
1007 writer.write_all(&their_sig.serialize_compact())?;
1011 htlc_source.write(writer)?;
1016 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
1017 writer.write_all(&[1; 1])?;
1018 serialize_local_tx!(prev_local_tx);
1020 writer.write_all(&[0; 1])?;
1023 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1024 writer.write_all(&[1; 1])?;
1025 serialize_local_tx!(cur_local_tx);
1027 writer.write_all(&[0; 1])?;
1030 if for_local_storage {
1031 writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
1033 writer.write_all(&byte_utils::be48_to_array(0))?;
1036 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
1037 for payment_preimage in self.payment_preimages.values() {
1038 writer.write_all(&payment_preimage.0[..])?;
1041 writer.write_all(&byte_utils::be64_to_array(self.pending_htlcs_updated.len() as u64))?;
1042 for data in self.pending_htlcs_updated.iter() {
1043 data.write(writer)?;
1046 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
1047 for event in self.pending_events.iter() {
1048 event.write(writer)?;
1051 self.last_block_hash.write(writer)?;
1052 if let Some((ref to_remote_script, ref local_key)) = self.to_remote_rescue {
1053 writer.write_all(&[1; 1])?;
1054 to_remote_script.write(writer)?;
1055 local_key.write(writer)?;
1057 writer.write_all(&[0; 1])?;
1060 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
1061 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
1062 writer.write_all(&byte_utils::be32_to_array(**target))?;
1063 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
1064 for ev in events.iter() {
1066 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1068 htlc_update.0.write(writer)?;
1069 htlc_update.1.write(writer)?;
1075 (self.outputs_to_watch.len() as u64).write(writer)?;
1076 for (txid, output_scripts) in self.outputs_to_watch.iter() {
1077 txid.write(writer)?;
1078 (output_scripts.len() as u64).write(writer)?;
1079 for script in output_scripts.iter() {
1080 script.write(writer)?;
1083 self.onchain_tx_handler.write(writer)?;
1088 /// Writes this monitor into the given writer, suitable for writing to disk.
1090 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1091 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1092 /// the "reorg path" (ie not just starting at the same height but starting at the highest
1093 /// common block that appears on your best chain as well as on the chain which contains the
1094 /// last block hash returned) upon deserializing the object!
1095 pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1096 self.write(writer, true)
1099 /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
1101 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1102 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1103 /// the "reorg path" (ie not just starting at the same height but starting at the highest
1104 /// common block that appears on your best chain as well as on the chain which contains the
1105 /// last block hash returned) upon deserializing the object!
1106 pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1107 self.write(writer, false)
1111 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
1112 pub(super) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
1113 our_to_self_delay: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1114 their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey,
1115 their_to_self_delay: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
1116 commitment_transaction_number_obscure_factor: u64,
1117 logger: Arc<Logger>) -> ChannelMonitor<ChanSigner> {
1119 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1120 let funding_key = keys.funding_key().clone();
1121 let revocation_base_key = keys.revocation_base_key().clone();
1122 let htlc_base_key = keys.htlc_base_key().clone();
1123 let delayed_payment_base_key = keys.delayed_payment_base_key().clone();
1124 let payment_base_key = keys.payment_base_key().clone();
1126 latest_update_id: 0,
1127 commitment_transaction_number_obscure_factor,
1129 destination_script: destination_script.clone(),
1130 broadcasted_local_revokable_script: None,
1132 key_storage: Storage::Local {
1135 revocation_base_key,
1137 delayed_payment_base_key,
1139 shutdown_pubkey: shutdown_pubkey.clone(),
1140 funding_info: Some(funding_info),
1141 current_remote_commitment_txid: None,
1142 prev_remote_commitment_txid: None,
1144 their_htlc_base_key: Some(their_htlc_base_key.clone()),
1145 their_delayed_payment_base_key: Some(their_delayed_payment_base_key.clone()),
1146 funding_redeemscript: Some(funding_redeemscript),
1147 channel_value_satoshis: Some(channel_value_satoshis),
1148 their_cur_revocation_points: None,
1150 our_to_self_delay: our_to_self_delay,
1151 their_to_self_delay: Some(their_to_self_delay),
1153 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1154 remote_claimable_outpoints: HashMap::new(),
1155 remote_commitment_txn_on_chain: HashMap::new(),
1156 remote_hash_commitment_number: HashMap::new(),
1158 prev_local_signed_commitment_tx: None,
1159 current_local_signed_commitment_tx: None,
1160 current_remote_commitment_number: 1 << 48,
1162 payment_preimages: HashMap::new(),
1163 pending_htlcs_updated: Vec::new(),
1164 pending_events: Vec::new(),
1166 to_remote_rescue: None,
1168 onchain_events_waiting_threshold_conf: HashMap::new(),
1169 outputs_to_watch: HashMap::new(),
1171 onchain_tx_handler: OnchainTxHandler::new(destination_script.clone(), logger.clone()),
1173 last_block_hash: Default::default(),
1174 secp_ctx: Secp256k1::new(),
1179 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1180 /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
1181 /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
1182 pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1183 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1184 return Err(MonitorUpdateError("Previous secret did not match new one"));
1187 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
1188 // events for now-revoked/fulfilled HTLCs.
1189 if let Storage::Local { ref mut prev_remote_commitment_txid, .. } = self.key_storage {
1190 if let Some(txid) = prev_remote_commitment_txid.take() {
1191 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
1197 if !self.payment_preimages.is_empty() {
1198 let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
1199 let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
1200 let min_idx = self.get_min_seen_secret();
1201 let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
1203 self.payment_preimages.retain(|&k, _| {
1204 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
1205 if k == htlc.payment_hash {
1209 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
1210 for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
1211 if k == htlc.payment_hash {
1216 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
1223 remote_hash_commitment_number.remove(&k);
1232 /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
1233 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1234 /// possibly future revocation/preimage information) to claim outputs where possible.
1235 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1236 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) {
1237 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1238 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1239 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1241 for &(ref htlc, _) in &htlc_outputs {
1242 self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1245 let new_txid = unsigned_commitment_tx.txid();
1246 log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1247 log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1248 if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage {
1249 *prev_remote_commitment_txid = current_remote_commitment_txid.take();
1250 *current_remote_commitment_txid = Some(new_txid);
1252 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
1253 self.current_remote_commitment_number = commitment_number;
1254 //TODO: Merge this into the other per-remote-transaction output storage stuff
1255 match self.their_cur_revocation_points {
1256 Some(old_points) => {
1257 if old_points.0 == commitment_number + 1 {
1258 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1259 } else if old_points.0 == commitment_number + 2 {
1260 if let Some(old_second_point) = old_points.2 {
1261 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1263 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1266 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1270 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1275 pub(super) fn provide_rescue_remote_commitment_tx_info(&mut self, their_revocation_point: PublicKey) {
1276 match self.key_storage {
1277 Storage::Local { ref payment_base_key, ref keys, .. } => {
1278 if let Ok(payment_key) = chan_utils::derive_public_key(&self.secp_ctx, &their_revocation_point, &keys.pubkeys().payment_basepoint) {
1279 let to_remote_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1280 .push_slice(&Hash160::hash(&payment_key.serialize())[..])
1282 if let Ok(to_remote_key) = chan_utils::derive_private_key(&self.secp_ctx, &their_revocation_point, &payment_base_key) {
1283 self.to_remote_rescue = Some((to_remote_script, to_remote_key));
1287 Storage::Watchtower { .. } => {}
1291 /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
1292 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1293 /// is important that any clones of this channel monitor (including remote clones) by kept
1294 /// up-to-date as our local commitment transaction is updated.
1295 /// Panics if set_their_to_self_delay has never been called.
1296 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> {
1297 if self.their_to_self_delay.is_none() {
1298 return Err(MonitorUpdateError("Got a local commitment tx info update before we'd set basic information about the channel"));
1300 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
1301 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
1302 txid: commitment_tx.txid(),
1304 revocation_key: local_keys.revocation_key,
1305 a_htlc_key: local_keys.a_htlc_key,
1306 b_htlc_key: local_keys.b_htlc_key,
1307 delayed_payment_key: local_keys.a_delayed_payment_key,
1308 per_commitment_point: local_keys.per_commitment_point,
1315 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1316 /// commitment_tx_infos which contain the payment hash have been revoked.
1317 pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
1318 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1321 pub(super) fn broadcast_latest_local_commitment_txn<B: Deref>(&mut self, broadcaster: &B)
1322 where B::Target: BroadcasterInterface,
1324 for tx in self.get_latest_local_commitment_txn().iter() {
1325 broadcaster.broadcast_transaction(tx);
1329 /// Used in Channel to cheat wrt the update_ids since it plays games, will be removed soon!
1330 pub(super) fn update_monitor_ooo(&mut self, mut updates: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
1331 for update in updates.updates.drain(..) {
1333 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
1334 self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
1335 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1336 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
1337 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1338 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1339 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1340 self.provide_secret(idx, secret)?,
1341 ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
1342 self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
1343 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
1346 self.latest_update_id = updates.update_id;
1350 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1353 /// panics if the given update is not the next update by update_id.
1354 pub fn update_monitor<B: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B) -> Result<(), MonitorUpdateError>
1355 where B::Target: BroadcasterInterface,
1357 if self.latest_update_id + 1 != updates.update_id {
1358 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1360 for update in updates.updates.drain(..) {
1362 ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, local_keys, feerate_per_kw, htlc_outputs } =>
1363 self.provide_latest_local_commitment_tx_info(commitment_tx, local_keys, feerate_per_kw, htlc_outputs)?,
1364 ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
1365 self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point),
1366 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
1367 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
1368 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
1369 self.provide_secret(idx, secret)?,
1370 ChannelMonitorUpdateStep::RescueRemoteCommitmentTXInfo { their_current_per_commitment_point } =>
1371 self.provide_rescue_remote_commitment_tx_info(their_current_per_commitment_point),
1372 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1373 if should_broadcast {
1374 self.broadcast_latest_local_commitment_txn(broadcaster);
1376 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");
1381 self.latest_update_id = updates.update_id;
1385 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1387 pub fn get_latest_update_id(&self) -> u64 {
1388 self.latest_update_id
1391 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1392 pub fn get_funding_txo(&self) -> Option<OutPoint> {
1393 match self.key_storage {
1394 Storage::Local { ref funding_info, .. } => {
1395 match funding_info {
1396 &Some((outpoint, _)) => Some(outpoint),
1400 Storage::Watchtower { .. } => {
1406 /// Gets a list of txids, with their output scripts (in the order they appear in the
1407 /// transaction), which we must learn about spends of via block_connected().
1408 pub fn get_outputs_to_watch(&self) -> &HashMap<Sha256dHash, Vec<Script>> {
1409 &self.outputs_to_watch
1412 /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
1413 /// Generally useful when deserializing as during normal operation the return values of
1414 /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
1415 /// that the get_funding_txo outpoint and transaction must also be monitored for!).
1416 pub fn get_monitored_outpoints(&self) -> Vec<(Sha256dHash, u32, &Script)> {
1417 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
1418 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
1419 for (idx, output) in outputs.iter().enumerate() {
1420 res.push(((*txid).clone(), idx as u32, output));
1426 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1427 /// ChannelManager via ManyChannelMonitor::get_and_clear_pending_htlcs_updated().
1428 pub fn get_and_clear_pending_htlcs_updated(&mut self) -> Vec<HTLCUpdate> {
1429 let mut ret = Vec::new();
1430 mem::swap(&mut ret, &mut self.pending_htlcs_updated);
1434 /// Gets the list of pending events which were generated by previous actions, clearing the list
1437 /// This is called by ManyChannelMonitor::get_and_clear_pending_events() and is equivalent to
1438 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1439 /// no internal locking in ChannelMonitors.
1440 pub fn get_and_clear_pending_events(&mut self) -> Vec<events::Event> {
1441 let mut ret = Vec::new();
1442 mem::swap(&mut ret, &mut self.pending_events);
1446 /// Can only fail if idx is < get_min_seen_secret
1447 pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1448 self.commitment_secrets.get_secret(idx)
1451 pub(super) fn get_min_seen_secret(&self) -> u64 {
1452 self.commitment_secrets.get_min_seen_secret()
1455 pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1456 self.current_remote_commitment_number
1459 pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1460 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1461 0xffff_ffff_ffff - ((((local_tx.tx.without_valid_witness().input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.without_valid_witness().lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor)
1462 } else { 0xffff_ffff_ffff }
1465 /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1466 /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1467 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1468 /// HTLC-Success/HTLC-Timeout transactions.
1469 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1470 /// revoked remote commitment tx
1471 fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<ClaimRequest>, (Sha256dHash, Vec<TxOut>), Vec<SpendableOutputDescriptor>) {
1472 // Most secp and related errors trying to create keys means we have no hope of constructing
1473 // a spend transaction...so we return no transactions to broadcast
1474 let mut claimable_outpoints = Vec::new();
1475 let mut watch_outputs = Vec::new();
1476 let mut spendable_outputs = Vec::new();
1478 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1479 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1481 macro_rules! ignore_error {
1482 ( $thing : expr ) => {
1485 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs)
1490 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);
1491 if commitment_number >= self.get_min_seen_secret() {
1492 let secret = self.get_secret(commitment_number).unwrap();
1493 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1494 let (revocation_pubkey, revocation_key, b_htlc_key, local_payment_key) = match self.key_storage {
1495 Storage::Local { ref keys, ref revocation_base_key, ref payment_base_key, .. } => {
1496 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1497 (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &keys.pubkeys().revocation_basepoint)),
1498 ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key)),
1499 ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &keys.pubkeys().htlc_basepoint)),
1500 Some(ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &payment_base_key))))
1502 Storage::Watchtower { .. } => {
1506 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()));
1507 let a_htlc_key = match self.their_htlc_base_key {
1508 None => return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs),
1509 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)),
1512 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1513 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1515 let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key {
1516 // Note that the Network here is ignored as we immediately drop the address for the
1517 // script_pubkey version.
1518 let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
1519 Some(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script())
1522 // First, process non-htlc outputs (to_local & to_remote)
1523 for (idx, outp) in tx.output.iter().enumerate() {
1524 if outp.script_pubkey == revokeable_p2wsh {
1525 let witness_data = InputMaterial::Revoked { witness_script: revokeable_redeemscript.clone(), pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: outp.value };
1526 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});
1527 } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() {
1528 spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1529 outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1530 key: local_payment_key.unwrap(),
1531 output: outp.clone(),
1536 // Then, try to find revoked htlc outputs
1537 if let Some(ref per_commitment_data) = per_commitment_option {
1538 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1539 if let Some(transaction_output_index) = htlc.transaction_output_index {
1540 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1541 if transaction_output_index as usize >= tx.output.len() ||
1542 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1543 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1544 return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user
1546 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 };
1547 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1552 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1553 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1554 // We're definitely a remote commitment transaction!
1555 log_trace!(self, "Got broadcast of revoked remote commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1556 watch_outputs.append(&mut tx.output.clone());
1557 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1559 macro_rules! check_htlc_fails {
1560 ($txid: expr, $commitment_tx: expr) => {
1561 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1562 for &(ref htlc, ref source_option) in outpoints.iter() {
1563 if let &Some(ref source) = source_option {
1564 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);
1565 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1566 hash_map::Entry::Occupied(mut entry) => {
1567 let e = entry.get_mut();
1568 e.retain(|ref event| {
1570 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1571 return htlc_update.0 != **source
1575 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1577 hash_map::Entry::Vacant(entry) => {
1578 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1586 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1587 if let &Some(ref txid) = current_remote_commitment_txid {
1588 check_htlc_fails!(txid, "current");
1590 if let &Some(ref txid) = prev_remote_commitment_txid {
1591 check_htlc_fails!(txid, "remote");
1594 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1596 } else if let Some(per_commitment_data) = per_commitment_option {
1597 // While this isn't useful yet, there is a potential race where if a counterparty
1598 // revokes a state at the same time as the commitment transaction for that state is
1599 // confirmed, and the watchtower receives the block before the user, the user could
1600 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1601 // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1602 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1604 watch_outputs.append(&mut tx.output.clone());
1605 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1607 log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1609 macro_rules! check_htlc_fails {
1610 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1611 if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1612 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1613 if let &Some(ref source) = source_option {
1614 // Check if the HTLC is present in the commitment transaction that was
1615 // broadcast, but not if it was below the dust limit, which we should
1616 // fail backwards immediately as there is no way for us to learn the
1617 // payment_preimage.
1618 // Note that if the dust limit were allowed to change between
1619 // commitment transactions we'd want to be check whether *any*
1620 // broadcastable commitment transaction has the HTLC in it, but it
1621 // cannot currently change after channel initialization, so we don't
1623 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1624 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1628 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);
1629 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1630 hash_map::Entry::Occupied(mut entry) => {
1631 let e = entry.get_mut();
1632 e.retain(|ref event| {
1634 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1635 return htlc_update.0 != **source
1639 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1641 hash_map::Entry::Vacant(entry) => {
1642 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1650 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1651 if let &Some(ref txid) = current_remote_commitment_txid {
1652 check_htlc_fails!(txid, "current", 'current_loop);
1654 if let &Some(ref txid) = prev_remote_commitment_txid {
1655 check_htlc_fails!(txid, "previous", 'prev_loop);
1659 if let Some(revocation_points) = self.their_cur_revocation_points {
1660 let revocation_point_option =
1661 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1662 else if let Some(point) = revocation_points.2.as_ref() {
1663 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1665 if let Some(revocation_point) = revocation_point_option {
1666 let (revocation_pubkey, b_htlc_key, htlc_privkey) = match self.key_storage {
1667 Storage::Local { ref keys, ref htlc_base_key, .. } => {
1668 (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &keys.pubkeys().revocation_basepoint)),
1669 ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &keys.pubkeys().htlc_basepoint)),
1670 ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1672 Storage::Watchtower { .. } => { unimplemented!() }
1674 let a_htlc_key = match self.their_htlc_base_key {
1675 None => return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs),
1676 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1679 // First, mark as spendable our to_remote output
1680 for (idx, outp) in tx.output.iter().enumerate() {
1681 if outp.script_pubkey.is_v0_p2wpkh() {
1682 match self.key_storage {
1683 Storage::Local { ref payment_base_key, .. } => {
1684 if let Ok(local_key) = chan_utils::derive_private_key(&self.secp_ctx, &revocation_point, &payment_base_key) {
1685 spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1686 outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1688 output: outp.clone(),
1692 Storage::Watchtower { .. } => {}
1694 break; // Only to_remote ouput is claimable
1698 // Then, try to find htlc outputs
1699 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1700 if let Some(transaction_output_index) = htlc.transaction_output_index {
1701 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1702 if transaction_output_index as usize >= tx.output.len() ||
1703 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1704 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1705 return (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs); // Corrupted per_commitment_data, fuck this user
1707 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1708 let aggregable = if !htlc.offered { false } else { true };
1709 if preimage.is_some() || !htlc.offered {
1710 let witness_data = InputMaterial::RemoteHTLC { witness_script: expected_script, key: htlc_privkey, preimage, amount: htlc.amount_msat / 1000, locktime: htlc.cltv_expiry };
1711 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1717 } else if let Some((ref to_remote_rescue, ref local_key)) = self.to_remote_rescue {
1718 for (idx, outp) in tx.output.iter().enumerate() {
1719 if to_remote_rescue == &outp.script_pubkey {
1720 spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1721 outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1722 key: local_key.clone(),
1723 output: outp.clone(),
1728 (claimable_outpoints, (commitment_txid, watch_outputs), spendable_outputs)
1731 /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1732 fn check_spend_remote_htlc(&mut self, tx: &Transaction, commitment_number: u64, height: u32) -> (Vec<ClaimRequest>, Option<(Sha256dHash, Vec<TxOut>)>) {
1733 let htlc_txid = tx.txid();
1734 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1735 return (Vec::new(), None)
1738 macro_rules! ignore_error {
1739 ( $thing : expr ) => {
1742 Err(_) => return (Vec::new(), None)
1747 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1748 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1749 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1750 let (revocation_pubkey, revocation_key) = match self.key_storage {
1751 Storage::Local { ref keys, ref revocation_base_key, .. } => {
1752 (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &keys.pubkeys().revocation_basepoint)),
1753 ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, revocation_base_key)))
1755 Storage::Watchtower { .. } => { unimplemented!() }
1757 let delayed_key = match self.their_delayed_payment_base_key {
1758 None => return (Vec::new(), None),
1759 Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1761 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1763 log_trace!(self, "Remote HTLC broadcast {}:{}", htlc_txid, 0);
1764 let witness_data = InputMaterial::Revoked { witness_script: redeemscript, pubkey: Some(revocation_pubkey), key: revocation_key, is_htlc: false, amount: tx.output[0].value };
1765 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 });
1766 (claimable_outpoints, Some((htlc_txid, tx.output.clone())))
1769 fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, delayed_payment_base_key: &SecretKey) -> (Vec<Transaction>, Vec<TxOut>, Option<(Script, SecretKey, Script)>) {
1770 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1771 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1773 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
1774 let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, delayed_payment_base_key) {
1775 Some((redeemscript.to_v0_p2wsh(), local_delayedkey, redeemscript))
1778 if let &Storage::Local { ref htlc_base_key, .. } = &self.key_storage {
1779 for &(ref htlc, ref sigs, _) in local_tx.htlc_outputs.iter() {
1780 if let Some(transaction_output_index) = htlc.transaction_output_index {
1781 if let &Some(ref their_sig) = sigs {
1783 log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions");
1784 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);
1785 let (our_sig, htlc_script) = match
1786 chan_utils::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, htlc_base_key, &self.secp_ctx) {
1791 let mut per_input_material = HashMap::with_capacity(1);
1792 per_input_material.insert(htlc_timeout_tx.input[0].previous_output, InputMaterial::LocalHTLC { witness_script: htlc_script, sigs: (*their_sig, our_sig), preimage: None, amount: htlc.amount_msat / 1000});
1793 //TODO: with option_simplified_commitment track outpoint too
1794 log_trace!(self, "Outpoint {}:{} is being being claimed", htlc_timeout_tx.input[0].previous_output.vout, htlc_timeout_tx.input[0].previous_output.txid);
1795 res.push(htlc_timeout_tx);
1797 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1798 log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions");
1799 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);
1800 let (our_sig, htlc_script) = match
1801 chan_utils::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, htlc_base_key, &self.secp_ctx) {
1806 let mut per_input_material = HashMap::with_capacity(1);
1807 per_input_material.insert(htlc_success_tx.input[0].previous_output, InputMaterial::LocalHTLC { witness_script: htlc_script, sigs: (*their_sig, our_sig), preimage: Some(*payment_preimage), amount: htlc.amount_msat / 1000});
1808 //TODO: with option_simplified_commitment track outpoint too
1809 log_trace!(self, "Outpoint {}:{} is being being claimed", htlc_success_tx.input[0].previous_output.vout, htlc_success_tx.input[0].previous_output.txid);
1810 res.push(htlc_success_tx);
1813 watch_outputs.push(local_tx.tx.without_valid_witness().output[transaction_output_index as usize].clone());
1814 } else { panic!("Should have sigs for non-dust local tx outputs!") }
1819 (res, watch_outputs, broadcasted_local_revokable_script)
1822 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1823 /// revoked using data in local_claimable_outpoints.
1824 /// Should not be used if check_spend_revoked_transaction succeeds.
1825 fn check_spend_local_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
1826 let commitment_txid = tx.txid();
1827 let mut local_txn = Vec::new();
1828 let mut watch_outputs = Vec::new();
1830 macro_rules! wait_threshold_conf {
1831 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1832 log_trace!(self, "Failing HTLC with payment_hash {} from {} local commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1833 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1834 hash_map::Entry::Occupied(mut entry) => {
1835 let e = entry.get_mut();
1836 e.retain(|ref event| {
1838 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1839 return htlc_update.0 != $source
1843 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1845 hash_map::Entry::Vacant(entry) => {
1846 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1852 macro_rules! append_onchain_update {
1853 ($updates: expr) => {
1854 local_txn.append(&mut $updates.0);
1855 watch_outputs.append(&mut $updates.1);
1856 self.broadcasted_local_revokable_script = $updates.2;
1860 // HTLCs set may differ between last and previous local commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1861 let mut is_local_tx = false;
1863 if let &mut Some(ref mut local_tx) = &mut self.current_local_signed_commitment_tx {
1864 if local_tx.txid == commitment_txid {
1865 match self.key_storage {
1866 Storage::Local { ref funding_key, .. } => {
1867 local_tx.tx.add_local_sig(funding_key, self.funding_redeemscript.as_ref().unwrap(), self.channel_value_satoshis.unwrap(), &self.secp_ctx);
1873 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1874 if local_tx.txid == commitment_txid {
1876 log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1877 assert!(local_tx.tx.has_local_sig());
1878 match self.key_storage {
1879 Storage::Local { ref delayed_payment_base_key, .. } => {
1880 let mut res = self.broadcast_by_local_state(local_tx, delayed_payment_base_key);
1881 append_onchain_update!(res);
1883 Storage::Watchtower { .. } => { }
1887 if let &mut Some(ref mut local_tx) = &mut self.prev_local_signed_commitment_tx {
1888 if local_tx.txid == commitment_txid {
1889 match self.key_storage {
1890 Storage::Local { ref funding_key, .. } => {
1891 local_tx.tx.add_local_sig(funding_key, self.funding_redeemscript.as_ref().unwrap(), self.channel_value_satoshis.unwrap(), &self.secp_ctx);
1897 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1898 if local_tx.txid == commitment_txid {
1900 log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1901 assert!(local_tx.tx.has_local_sig());
1902 match self.key_storage {
1903 Storage::Local { ref delayed_payment_base_key, .. } => {
1904 let mut res = self.broadcast_by_local_state(local_tx, delayed_payment_base_key);
1905 append_onchain_update!(res);
1907 Storage::Watchtower { .. } => { }
1912 macro_rules! fail_dust_htlcs_after_threshold_conf {
1913 ($local_tx: expr) => {
1914 for &(ref htlc, _, ref source) in &$local_tx.htlc_outputs {
1915 if htlc.transaction_output_index.is_none() {
1916 if let &Some(ref source) = source {
1917 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1925 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1926 fail_dust_htlcs_after_threshold_conf!(local_tx);
1928 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1929 fail_dust_htlcs_after_threshold_conf!(local_tx);
1933 (local_txn, (commitment_txid, watch_outputs))
1936 /// Generate a spendable output event when closing_transaction get registered onchain.
1937 fn check_spend_closing_transaction(&self, tx: &Transaction) -> Option<SpendableOutputDescriptor> {
1938 if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 {
1939 match self.key_storage {
1940 Storage::Local { ref shutdown_pubkey, .. } => {
1941 let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
1942 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1943 for (idx, output) in tx.output.iter().enumerate() {
1944 if shutdown_script == output.script_pubkey {
1945 return Some(SpendableOutputDescriptor::StaticOutput {
1946 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: idx as u32 },
1947 output: output.clone(),
1952 Storage::Watchtower { .. } => {
1953 //TODO: we need to ensure an offline client will generate the event when it
1954 // comes back online after only the watchtower saw the transaction
1961 /// Used by ChannelManager deserialization to broadcast the latest local state if its copy of
1962 /// the Channel was out-of-date. You may use it to get a broadcastable local toxic tx in case of
1963 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our remote side knows
1964 /// a higher revocation secret than the local commitment number we are aware of. Broadcasting these
1965 /// transactions are UNSAFE, as they allow remote side to punish you. Nevertheless you may want to
1966 /// broadcast them if remote don't close channel with his higher commitment transaction after a
1967 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1968 /// out-of-band the other node operator to coordinate with him if option is available to you.
1969 /// In any-case, choice is up to the user.
1970 pub fn get_latest_local_commitment_txn(&mut self) -> Vec<Transaction> {
1971 // TODO: We should likely move all of the logic in here into OnChainTxHandler and unify it
1972 // to ensure add_local_sig is only ever called once no matter what. This likely includes
1973 // tracking state and panic!()ing if we get an update after force-closure/local-tx signing.
1974 log_trace!(self, "Getting signed latest local commitment transaction!");
1975 if let &mut Some(ref mut local_tx) = &mut self.current_local_signed_commitment_tx {
1976 match self.key_storage {
1977 Storage::Local { ref funding_key, .. } => {
1978 local_tx.tx.add_local_sig(funding_key, self.funding_redeemscript.as_ref().unwrap(), self.channel_value_satoshis.unwrap(), &self.secp_ctx);
1983 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1984 let mut res = vec![local_tx.tx.with_valid_witness().clone()];
1985 match self.key_storage {
1986 Storage::Local { ref delayed_payment_base_key, .. } => {
1987 res.append(&mut self.broadcast_by_local_state(local_tx, delayed_payment_base_key).0);
1988 // 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.
1989 // The data will be re-generated and tracked in check_spend_local_transaction if we get a confirmation.
1991 _ => panic!("Can only broadcast by local channelmonitor"),
1999 /// Called by SimpleManyChannelMonitor::block_connected, which implements
2000 /// ChainListener::block_connected.
2001 /// Eventually this should be pub and, roughly, implement ChainListener, however this requires
2002 /// &mut self, as well as returns new spendable outputs and outpoints to watch for spending of
2004 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>)>
2005 where B::Target: BroadcasterInterface,
2006 F::Target: FeeEstimator
2008 for tx in txn_matched {
2009 let mut output_val = 0;
2010 for out in tx.output.iter() {
2011 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2012 output_val += out.value;
2013 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2017 log_trace!(self, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
2018 let mut watch_outputs = Vec::new();
2019 let mut spendable_outputs = Vec::new();
2020 let mut claimable_outpoints = Vec::new();
2021 for tx in txn_matched {
2022 if tx.input.len() == 1 {
2023 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2024 // commitment transactions and HTLC transactions will all only ever have one input,
2025 // which is an easy way to filter out any potential non-matching txn for lazy
2027 let prevout = &tx.input[0].previous_output;
2028 let funding_txo = match self.key_storage {
2029 Storage::Local { ref funding_info, .. } => {
2030 funding_info.clone()
2032 Storage::Watchtower { .. } => {
2036 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) {
2037 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
2038 let (mut new_outpoints, new_outputs, mut spendable_output) = self.check_spend_remote_transaction(&tx, height);
2039 spendable_outputs.append(&mut spendable_output);
2040 if !new_outputs.1.is_empty() {
2041 watch_outputs.push(new_outputs);
2043 if new_outpoints.is_empty() {
2044 let (local_txn, new_outputs) = self.check_spend_local_transaction(&tx, height);
2045 for tx in local_txn.iter() {
2046 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
2047 broadcaster.broadcast_transaction(tx);
2049 if !new_outputs.1.is_empty() {
2050 watch_outputs.push(new_outputs);
2053 claimable_outpoints.append(&mut new_outpoints);
2055 if !funding_txo.is_none() && claimable_outpoints.is_empty() {
2056 if let Some(spendable_output) = self.check_spend_closing_transaction(&tx) {
2057 spendable_outputs.push(spendable_output);
2061 if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
2062 let (mut new_outpoints, new_outputs_option) = self.check_spend_remote_htlc(&tx, commitment_number, height);
2063 claimable_outpoints.append(&mut new_outpoints);
2064 if let Some(new_outputs) = new_outputs_option {
2065 watch_outputs.push(new_outputs);
2070 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2071 // can also be resolved in a few other ways which can have more than one output. Thus,
2072 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2073 self.is_resolving_htlc_output(&tx, height);
2075 if let Some(spendable_output) = self.is_paying_spendable_output(&tx) {
2076 spendable_outputs.push(spendable_output);
2079 let should_broadcast = if let Some(_) = self.current_local_signed_commitment_tx {
2080 self.would_broadcast_at_height(height)
2082 if let Some(ref mut cur_local_tx) = self.current_local_signed_commitment_tx {
2083 if should_broadcast {
2084 match self.key_storage {
2085 Storage::Local { ref funding_key, .. } => {
2086 cur_local_tx.tx.add_local_sig(funding_key, self.funding_redeemscript.as_ref().unwrap(), self.channel_value_satoshis.unwrap(), &self.secp_ctx);
2092 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
2093 if should_broadcast {
2094 log_trace!(self, "Broadcast onchain {}", log_tx!(cur_local_tx.tx.with_valid_witness()));
2095 broadcaster.broadcast_transaction(&cur_local_tx.tx.with_valid_witness());
2096 match self.key_storage {
2097 Storage::Local { ref delayed_payment_base_key, .. } => {
2098 let (txs, new_outputs, _) = self.broadcast_by_local_state(&cur_local_tx, delayed_payment_base_key);
2099 if !new_outputs.is_empty() {
2100 watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
2103 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
2104 broadcaster.broadcast_transaction(&tx);
2107 Storage::Watchtower { .. } => { },
2111 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
2114 OnchainEvent::HTLCUpdate { htlc_update } => {
2115 log_trace!(self, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
2116 self.pending_htlcs_updated.push(HTLCUpdate {
2117 payment_hash: htlc_update.1,
2118 payment_preimage: None,
2119 source: htlc_update.0,
2125 self.onchain_tx_handler.block_connected(txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator);
2127 self.last_block_hash = block_hash.clone();
2128 for &(ref txid, ref output_scripts) in watch_outputs.iter() {
2129 self.outputs_to_watch.insert(txid.clone(), output_scripts.iter().map(|o| o.script_pubkey.clone()).collect());
2132 for spend in spendable_outputs.iter() {
2133 log_trace!(self, "Announcing spendable output to user: {}", log_spendable!(spend));
2136 if spendable_outputs.len() > 0 {
2137 self.pending_events.push(events::Event::SpendableOutputs {
2138 outputs: spendable_outputs,
2145 fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, block_hash: &Sha256dHash, broadcaster: B, fee_estimator: F)
2146 where B::Target: BroadcasterInterface,
2147 F::Target: FeeEstimator
2149 log_trace!(self, "Block {} at height {} disconnected", block_hash, height);
2150 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
2152 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2155 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator);
2157 self.last_block_hash = block_hash.clone();
2160 pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
2161 // We need to consider all HTLCs which are:
2162 // * in any unrevoked remote commitment transaction, as they could broadcast said
2163 // transactions and we'd end up in a race, or
2164 // * are in our latest local commitment transaction, as this is the thing we will
2165 // broadcast if we go on-chain.
2166 // Note that we consider HTLCs which were below dust threshold here - while they don't
2167 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2168 // to the source, and if we don't fail the channel we will have to ensure that the next
2169 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2170 // easier to just fail the channel as this case should be rare enough anyway.
2171 macro_rules! scan_commitment {
2172 ($htlcs: expr, $local_tx: expr) => {
2173 for ref htlc in $htlcs {
2174 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2175 // chain with enough room to claim the HTLC without our counterparty being able to
2176 // time out the HTLC first.
2177 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2178 // concern is being able to claim the corresponding inbound HTLC (on another
2179 // channel) before it expires. In fact, we don't even really care if our
2180 // counterparty here claims such an outbound HTLC after it expired as long as we
2181 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2182 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2183 // we give ourselves a few blocks of headroom after expiration before going
2184 // on-chain for an expired HTLC.
2185 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2186 // from us until we've reached the point where we go on-chain with the
2187 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2188 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2189 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2190 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2191 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2192 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2193 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2194 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2195 // The final, above, condition is checked for statically in channelmanager
2196 // with CHECK_CLTV_EXPIRY_SANITY_2.
2197 let htlc_outbound = $local_tx == htlc.offered;
2198 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2199 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2200 log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2207 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
2208 scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2211 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
2212 if let &Some(ref txid) = current_remote_commitment_txid {
2213 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2214 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2217 if let &Some(ref txid) = prev_remote_commitment_txid {
2218 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
2219 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2227 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
2228 /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2229 fn is_resolving_htlc_output(&mut self, tx: &Transaction, height: u32) {
2230 'outer_loop: for input in &tx.input {
2231 let mut payment_data = None;
2232 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2233 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2234 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2235 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2237 macro_rules! log_claim {
2238 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
2239 // We found the output in question, but aren't failing it backwards
2240 // as we have no corresponding source and no valid remote commitment txid
2241 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2242 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2243 let outbound_htlc = $local_tx == $htlc.offered;
2244 if ($local_tx && revocation_sig_claim) ||
2245 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2246 log_error!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2247 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2248 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2249 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2251 log_info!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2252 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2253 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2254 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2259 macro_rules! check_htlc_valid_remote {
2260 ($remote_txid: expr, $htlc_output: expr) => {
2261 if let &Some(txid) = $remote_txid {
2262 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
2263 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2264 if let &Some(ref source) = pending_source {
2265 log_claim!("revoked remote commitment tx", false, pending_htlc, true);
2266 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2275 macro_rules! scan_commitment {
2276 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
2277 for (ref htlc_output, source_option) in $htlcs {
2278 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2279 if let Some(ref source) = source_option {
2280 log_claim!($tx_info, $local_tx, htlc_output, true);
2281 // We have a resolution of an HTLC either from one of our latest
2282 // local commitment transactions or an unrevoked remote commitment
2283 // transaction. This implies we either learned a preimage, the HTLC
2284 // has timed out, or we screwed up. In any case, we should now
2285 // resolve the source HTLC with the original sender.
2286 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2287 } else if !$local_tx {
2288 if let Storage::Local { ref current_remote_commitment_txid, .. } = self.key_storage {
2289 check_htlc_valid_remote!(current_remote_commitment_txid, htlc_output);
2291 if payment_data.is_none() {
2292 if let Storage::Local { ref prev_remote_commitment_txid, .. } = self.key_storage {
2293 check_htlc_valid_remote!(prev_remote_commitment_txid, htlc_output);
2297 if payment_data.is_none() {
2298 log_claim!($tx_info, $local_tx, htlc_output, false);
2299 continue 'outer_loop;
2306 if let Some(ref current_local_signed_commitment_tx) = self.current_local_signed_commitment_tx {
2307 if input.previous_output.txid == current_local_signed_commitment_tx.txid {
2308 scan_commitment!(current_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2309 "our latest local commitment tx", true);
2312 if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2313 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2314 scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2315 "our previous local commitment tx", true);
2318 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2319 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2320 "remote commitment tx", false);
2323 // Check that scan_commitment, above, decided there is some source worth relaying an
2324 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2325 if let Some((source, payment_hash)) = payment_data {
2326 let mut payment_preimage = PaymentPreimage([0; 32]);
2327 if accepted_preimage_claim {
2328 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2329 payment_preimage.0.copy_from_slice(&input.witness[3]);
2330 self.pending_htlcs_updated.push(HTLCUpdate {
2332 payment_preimage: Some(payment_preimage),
2336 } else if offered_preimage_claim {
2337 if !self.pending_htlcs_updated.iter().any(|update| update.source == source) {
2338 payment_preimage.0.copy_from_slice(&input.witness[1]);
2339 self.pending_htlcs_updated.push(HTLCUpdate {
2341 payment_preimage: Some(payment_preimage),
2346 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);
2347 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2348 hash_map::Entry::Occupied(mut entry) => {
2349 let e = entry.get_mut();
2350 e.retain(|ref event| {
2352 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2353 return htlc_update.0 != source
2357 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2359 hash_map::Entry::Vacant(entry) => {
2360 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2368 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2369 fn is_paying_spendable_output(&self, tx: &Transaction) -> Option<SpendableOutputDescriptor> {
2370 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2371 if outp.script_pubkey == self.destination_script {
2372 return Some(SpendableOutputDescriptor::StaticOutput {
2373 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2374 output: outp.clone(),
2376 } else if let Some(ref broadcasted_local_revokable_script) = self.broadcasted_local_revokable_script {
2377 if broadcasted_local_revokable_script.0 == outp.script_pubkey {
2378 return Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2379 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: i as u32 },
2380 key: broadcasted_local_revokable_script.1,
2381 witness_script: broadcasted_local_revokable_script.2.clone(),
2382 to_self_delay: self.their_to_self_delay.unwrap(),
2383 output: outp.clone(),
2392 const MAX_ALLOC_SIZE: usize = 64*1024;
2394 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dHash, ChannelMonitor<ChanSigner>) {
2395 fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
2396 macro_rules! unwrap_obj {
2400 Err(_) => return Err(DecodeError::InvalidValue),
2405 let _ver: u8 = Readable::read(reader)?;
2406 let min_ver: u8 = Readable::read(reader)?;
2407 if min_ver > SERIALIZATION_VERSION {
2408 return Err(DecodeError::UnknownVersion);
2411 let latest_update_id: u64 = Readable::read(reader)?;
2412 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2414 let destination_script = Readable::read(reader)?;
2415 let broadcasted_local_revokable_script = match <u8 as Readable>::read(reader)? {
2417 let revokable_address = Readable::read(reader)?;
2418 let local_delayedkey = Readable::read(reader)?;
2419 let revokable_script = Readable::read(reader)?;
2420 Some((revokable_address, local_delayedkey, revokable_script))
2423 _ => return Err(DecodeError::InvalidValue),
2426 let key_storage = match <u8 as Readable>::read(reader)? {
2428 let keys = Readable::read(reader)?;
2429 let funding_key = Readable::read(reader)?;
2430 let revocation_base_key = Readable::read(reader)?;
2431 let htlc_base_key = Readable::read(reader)?;
2432 let delayed_payment_base_key = Readable::read(reader)?;
2433 let payment_base_key = Readable::read(reader)?;
2434 let shutdown_pubkey = Readable::read(reader)?;
2435 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2436 // barely-init'd ChannelMonitors that we can't do anything with.
2437 let outpoint = OutPoint {
2438 txid: Readable::read(reader)?,
2439 index: Readable::read(reader)?,
2441 let funding_info = Some((outpoint, Readable::read(reader)?));
2442 let current_remote_commitment_txid = Readable::read(reader)?;
2443 let prev_remote_commitment_txid = Readable::read(reader)?;
2447 revocation_base_key,
2449 delayed_payment_base_key,
2453 current_remote_commitment_txid,
2454 prev_remote_commitment_txid,
2457 _ => return Err(DecodeError::InvalidValue),
2460 let their_htlc_base_key = Some(Readable::read(reader)?);
2461 let their_delayed_payment_base_key = Some(Readable::read(reader)?);
2462 let funding_redeemscript = Some(Readable::read(reader)?);
2463 let channel_value_satoshis = Some(Readable::read(reader)?);
2465 let their_cur_revocation_points = {
2466 let first_idx = <U48 as Readable>::read(reader)?.0;
2470 let first_point = Readable::read(reader)?;
2471 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2472 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2473 Some((first_idx, first_point, None))
2475 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2480 let our_to_self_delay: u16 = Readable::read(reader)?;
2481 let their_to_self_delay: Option<u16> = Some(Readable::read(reader)?);
2483 let commitment_secrets = Readable::read(reader)?;
2485 macro_rules! read_htlc_in_commitment {
2488 let offered: bool = Readable::read(reader)?;
2489 let amount_msat: u64 = Readable::read(reader)?;
2490 let cltv_expiry: u32 = Readable::read(reader)?;
2491 let payment_hash: PaymentHash = Readable::read(reader)?;
2492 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2494 HTLCOutputInCommitment {
2495 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2501 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2502 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2503 for _ in 0..remote_claimable_outpoints_len {
2504 let txid: Sha256dHash = Readable::read(reader)?;
2505 let htlcs_count: u64 = Readable::read(reader)?;
2506 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2507 for _ in 0..htlcs_count {
2508 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2510 if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2511 return Err(DecodeError::InvalidValue);
2515 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2516 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2517 for _ in 0..remote_commitment_txn_on_chain_len {
2518 let txid: Sha256dHash = Readable::read(reader)?;
2519 let commitment_number = <U48 as Readable>::read(reader)?.0;
2520 let outputs_count = <u64 as Readable>::read(reader)?;
2521 let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2522 for _ in 0..outputs_count {
2523 outputs.push(Readable::read(reader)?);
2525 if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2526 return Err(DecodeError::InvalidValue);
2530 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2531 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2532 for _ in 0..remote_hash_commitment_number_len {
2533 let payment_hash: PaymentHash = Readable::read(reader)?;
2534 let commitment_number = <U48 as Readable>::read(reader)?.0;
2535 if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2536 return Err(DecodeError::InvalidValue);
2540 macro_rules! read_local_tx {
2543 let tx = <LocalCommitmentTransaction as Readable>::read(reader)?;
2544 let revocation_key = Readable::read(reader)?;
2545 let a_htlc_key = Readable::read(reader)?;
2546 let b_htlc_key = Readable::read(reader)?;
2547 let delayed_payment_key = Readable::read(reader)?;
2548 let per_commitment_point = Readable::read(reader)?;
2549 let feerate_per_kw: u64 = Readable::read(reader)?;
2551 let htlcs_len: u64 = Readable::read(reader)?;
2552 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2553 for _ in 0..htlcs_len {
2554 let htlc = read_htlc_in_commitment!();
2555 let sigs = match <u8 as Readable>::read(reader)? {
2557 1 => Some(Readable::read(reader)?),
2558 _ => return Err(DecodeError::InvalidValue),
2560 htlcs.push((htlc, sigs, Readable::read(reader)?));
2565 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2572 let prev_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2575 Some(read_local_tx!())
2577 _ => return Err(DecodeError::InvalidValue),
2580 let current_local_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2583 Some(read_local_tx!())
2585 _ => return Err(DecodeError::InvalidValue),
2588 let current_remote_commitment_number = <U48 as Readable>::read(reader)?.0;
2590 let payment_preimages_len: u64 = Readable::read(reader)?;
2591 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2592 for _ in 0..payment_preimages_len {
2593 let preimage: PaymentPreimage = Readable::read(reader)?;
2594 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2595 if let Some(_) = payment_preimages.insert(hash, preimage) {
2596 return Err(DecodeError::InvalidValue);
2600 let pending_htlcs_updated_len: u64 = Readable::read(reader)?;
2601 let mut pending_htlcs_updated = Vec::with_capacity(cmp::min(pending_htlcs_updated_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2602 for _ in 0..pending_htlcs_updated_len {
2603 pending_htlcs_updated.push(Readable::read(reader)?);
2606 let pending_events_len: u64 = Readable::read(reader)?;
2607 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<events::Event>()));
2608 for _ in 0..pending_events_len {
2609 if let Some(event) = MaybeReadable::read(reader)? {
2610 pending_events.push(event);
2614 let last_block_hash: Sha256dHash = Readable::read(reader)?;
2615 let to_remote_rescue = match <u8 as Readable>::read(reader)? {
2618 let to_remote_script = Readable::read(reader)?;
2619 let local_key = Readable::read(reader)?;
2620 Some((to_remote_script, local_key))
2622 _ => return Err(DecodeError::InvalidValue),
2625 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2626 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2627 for _ in 0..waiting_threshold_conf_len {
2628 let height_target = Readable::read(reader)?;
2629 let events_len: u64 = Readable::read(reader)?;
2630 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2631 for _ in 0..events_len {
2632 let ev = match <u8 as Readable>::read(reader)? {
2634 let htlc_source = Readable::read(reader)?;
2635 let hash = Readable::read(reader)?;
2636 OnchainEvent::HTLCUpdate {
2637 htlc_update: (htlc_source, hash)
2640 _ => return Err(DecodeError::InvalidValue),
2644 onchain_events_waiting_threshold_conf.insert(height_target, events);
2647 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2648 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>>())));
2649 for _ in 0..outputs_to_watch_len {
2650 let txid = Readable::read(reader)?;
2651 let outputs_len: u64 = Readable::read(reader)?;
2652 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Script>()));
2653 for _ in 0..outputs_len {
2654 outputs.push(Readable::read(reader)?);
2656 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2657 return Err(DecodeError::InvalidValue);
2660 let onchain_tx_handler = ReadableArgs::read(reader, logger.clone())?;
2662 Ok((last_block_hash.clone(), ChannelMonitor {
2664 commitment_transaction_number_obscure_factor,
2667 broadcasted_local_revokable_script,
2670 their_htlc_base_key,
2671 their_delayed_payment_base_key,
2672 funding_redeemscript,
2673 channel_value_satoshis,
2674 their_cur_revocation_points,
2677 their_to_self_delay,
2680 remote_claimable_outpoints,
2681 remote_commitment_txn_on_chain,
2682 remote_hash_commitment_number,
2684 prev_local_signed_commitment_tx,
2685 current_local_signed_commitment_tx,
2686 current_remote_commitment_number,
2689 pending_htlcs_updated,
2694 onchain_events_waiting_threshold_conf,
2700 secp_ctx: Secp256k1::new(),
2708 use bitcoin::blockdata::script::{Script, Builder};
2709 use bitcoin::blockdata::opcodes;
2710 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2711 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2712 use bitcoin::util::bip143;
2713 use bitcoin_hashes::Hash;
2714 use bitcoin_hashes::sha256::Hash as Sha256;
2715 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
2716 use bitcoin_hashes::hex::FromHex;
2718 use chain::transaction::OutPoint;
2719 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2720 use ln::channelmonitor::ChannelMonitor;
2721 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2723 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys, LocalCommitmentTransaction};
2724 use util::test_utils::TestLogger;
2725 use secp256k1::key::{SecretKey,PublicKey};
2726 use secp256k1::Secp256k1;
2727 use rand::{thread_rng,Rng};
2729 use chain::keysinterface::InMemoryChannelKeys;
2732 fn test_prune_preimages() {
2733 let secp_ctx = Secp256k1::new();
2734 let logger = Arc::new(TestLogger::new());
2736 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2737 macro_rules! dummy_keys {
2741 per_commitment_point: dummy_key.clone(),
2742 revocation_key: dummy_key.clone(),
2743 a_htlc_key: dummy_key.clone(),
2744 b_htlc_key: dummy_key.clone(),
2745 a_delayed_payment_key: dummy_key.clone(),
2746 b_payment_key: dummy_key.clone(),
2751 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2753 let mut preimages = Vec::new();
2755 let mut rng = thread_rng();
2757 let mut preimage = PaymentPreimage([0; 32]);
2758 rng.fill_bytes(&mut preimage.0[..]);
2759 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2760 preimages.push((preimage, hash));
2764 macro_rules! preimages_slice_to_htlc_outputs {
2765 ($preimages_slice: expr) => {
2767 let mut res = Vec::new();
2768 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2769 res.push((HTLCOutputInCommitment {
2773 payment_hash: preimage.1.clone(),
2774 transaction_output_index: Some(idx as u32),
2781 macro_rules! preimages_to_local_htlcs {
2782 ($preimages_slice: expr) => {
2784 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2785 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2791 macro_rules! test_preimages_exist {
2792 ($preimages_slice: expr, $monitor: expr) => {
2793 for preimage in $preimages_slice {
2794 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2799 let keys = InMemoryChannelKeys::new(
2801 SecretKey::from_slice(&[41; 32]).unwrap(),
2802 SecretKey::from_slice(&[41; 32]).unwrap(),
2803 SecretKey::from_slice(&[41; 32]).unwrap(),
2804 SecretKey::from_slice(&[41; 32]).unwrap(),
2805 SecretKey::from_slice(&[41; 32]).unwrap(),
2810 // Prune with one old state and a local commitment tx holding a few overlaps with the
2812 let mut monitor = ChannelMonitor::new(keys,
2813 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2814 (OutPoint { txid: Sha256dHash::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2815 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2816 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2817 0, Script::new(), 46, 0, logger.clone());
2819 monitor.their_to_self_delay = Some(10);
2821 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10])).unwrap();
2822 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
2823 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
2824 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
2825 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key);
2826 for &(ref preimage, ref hash) in preimages.iter() {
2827 monitor.provide_payment_preimage(hash, preimage);
2830 // Now provide a secret, pruning preimages 10-15
2831 let mut secret = [0; 32];
2832 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2833 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2834 assert_eq!(monitor.payment_preimages.len(), 15);
2835 test_preimages_exist!(&preimages[0..10], monitor);
2836 test_preimages_exist!(&preimages[15..20], monitor);
2838 // Now provide a further secret, pruning preimages 15-17
2839 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2840 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2841 assert_eq!(monitor.payment_preimages.len(), 13);
2842 test_preimages_exist!(&preimages[0..10], monitor);
2843 test_preimages_exist!(&preimages[17..20], monitor);
2845 // Now update local commitment tx info, pruning only element 18 as we still care about the
2846 // previous commitment tx's preimages too
2847 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5])).unwrap();
2848 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2849 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2850 assert_eq!(monitor.payment_preimages.len(), 12);
2851 test_preimages_exist!(&preimages[0..10], monitor);
2852 test_preimages_exist!(&preimages[18..20], monitor);
2854 // But if we do it again, we'll prune 5-10
2855 monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::dummy(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3])).unwrap();
2856 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2857 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2858 assert_eq!(monitor.payment_preimages.len(), 5);
2859 test_preimages_exist!(&preimages[0..5], monitor);
2863 fn test_claim_txn_weight_computation() {
2864 // We test Claim txn weight, knowing that we want expected weigth and
2865 // not actual case to avoid sigs and time-lock delays hell variances.
2867 let secp_ctx = Secp256k1::new();
2868 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2869 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2870 let mut sum_actual_sigs = 0;
2872 macro_rules! sign_input {
2873 ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2874 let htlc = HTLCOutputInCommitment {
2875 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2877 cltv_expiry: 2 << 16,
2878 payment_hash: PaymentHash([1; 32]),
2879 transaction_output_index: Some($idx),
2881 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2882 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2883 let sig = secp_ctx.sign(&sighash, &privkey);
2884 $input.witness.push(sig.serialize_der().to_vec());
2885 $input.witness[0].push(SigHashType::All as u8);
2886 sum_actual_sigs += $input.witness[0].len();
2887 if *$input_type == InputDescriptors::RevokedOutput {
2888 $input.witness.push(vec!(1));
2889 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2890 $input.witness.push(pubkey.clone().serialize().to_vec());
2891 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2892 $input.witness.push(vec![0]);
2894 $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2896 $input.witness.push(redeem_script.into_bytes());
2897 println!("witness[0] {}", $input.witness[0].len());
2898 println!("witness[1] {}", $input.witness[1].len());
2899 println!("witness[2] {}", $input.witness[2].len());
2903 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2904 let txid = Sha256dHash::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2906 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2907 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2909 claim_tx.input.push(TxIn {
2910 previous_output: BitcoinOutPoint {
2914 script_sig: Script::new(),
2915 sequence: 0xfffffffd,
2916 witness: Vec::new(),
2919 claim_tx.output.push(TxOut {
2920 script_pubkey: script_pubkey.clone(),
2923 let base_weight = claim_tx.get_weight();
2924 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2925 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2926 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2927 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2929 assert_eq!(base_weight + OnchainTxHandler::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2931 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2932 claim_tx.input.clear();
2933 sum_actual_sigs = 0;
2935 claim_tx.input.push(TxIn {
2936 previous_output: BitcoinOutPoint {
2940 script_sig: Script::new(),
2941 sequence: 0xfffffffd,
2942 witness: Vec::new(),
2945 let base_weight = claim_tx.get_weight();
2946 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2947 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2948 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2949 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2951 assert_eq!(base_weight + OnchainTxHandler::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2953 // Justice tx with 1 revoked HTLC-Success tx output
2954 claim_tx.input.clear();
2955 sum_actual_sigs = 0;
2956 claim_tx.input.push(TxIn {
2957 previous_output: BitcoinOutPoint {
2961 script_sig: Script::new(),
2962 sequence: 0xfffffffd,
2963 witness: Vec::new(),
2965 let base_weight = claim_tx.get_weight();
2966 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2967 let inputs_des = vec![InputDescriptors::RevokedOutput];
2968 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2969 sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2971 assert_eq!(base_weight + OnchainTxHandler::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
2974 // Further testing is done in the ChannelManager integration tests.