1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
23 //! [`chain::Watch`]: ../trait.Watch.html
25 use bitcoin::blockdata::block::{Block, BlockHeader};
26 use bitcoin::blockdata::transaction::{TxOut,Transaction};
27 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
28 use bitcoin::blockdata::script::{Script, Builder};
29 use bitcoin::blockdata::opcodes;
31 use bitcoin::hashes::Hash;
32 use bitcoin::hashes::sha256::Hash as Sha256;
33 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
35 use bitcoin::secp256k1::{Secp256k1,Signature};
36 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
37 use bitcoin::secp256k1;
39 use ln::msgs::DecodeError;
41 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
42 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
43 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
45 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
46 use chain::transaction::{OutPoint, TransactionData};
47 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
48 use util::logger::Logger;
49 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
51 use util::events::Event;
53 use std::collections::{HashMap, HashSet, hash_map};
59 /// An update generated by the underlying Channel itself which contains some new information the
60 /// ChannelMonitor should be made aware of.
61 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
64 pub struct ChannelMonitorUpdate {
65 pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
66 /// The sequence number of this update. Updates *must* be replayed in-order according to this
67 /// sequence number (and updates may panic if they are not). The update_id values are strictly
68 /// increasing and increase by one for each new update, with one exception specified below.
70 /// This sequence number is also used to track up to which points updates which returned
71 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
72 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
74 /// The only instance where update_id values are not strictly increasing is the case where we
75 /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
76 /// its docs for more details.
78 /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
83 /// (1) a channel has been force closed and
84 /// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
85 /// this channel's (the backward link's) broadcasted commitment transaction
86 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
87 /// with the update providing said payment preimage. No other update types are allowed after
89 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
91 impl Writeable for ChannelMonitorUpdate {
92 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
93 self.update_id.write(w)?;
94 (self.updates.len() as u64).write(w)?;
95 for update_step in self.updates.iter() {
96 update_step.write(w)?;
101 impl Readable for ChannelMonitorUpdate {
102 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
103 let update_id: u64 = Readable::read(r)?;
104 let len: u64 = Readable::read(r)?;
105 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
107 updates.push(Readable::read(r)?);
109 Ok(Self { update_id, updates })
113 /// An error enum representing a failure to persist a channel monitor update.
114 #[derive(Clone, Debug)]
115 pub enum ChannelMonitorUpdateErr {
116 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
117 /// our state failed, but is expected to succeed at some point in the future).
119 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
120 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
121 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
122 /// restore the channel to an operational state.
124 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
125 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
126 /// writing out the latest ChannelManager state.
128 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
129 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
130 /// to claim it on this channel) and those updates must be applied wherever they can be. At
131 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
132 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
133 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
136 /// Note that even if updates made after TemporaryFailure succeed you must still call
137 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
140 /// Note that the update being processed here will not be replayed for you when you call
141 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
142 /// with the persisted ChannelMonitor on your own local disk prior to returning a
143 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
144 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
147 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
148 /// remote location (with local copies persisted immediately), it is anticipated that all
149 /// updates will return TemporaryFailure until the remote copies could be updated.
151 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
152 /// different watchtower and cannot update with all watchtowers that were previously informed
153 /// of this channel).
155 /// At reception of this error, ChannelManager will force-close the channel and return at
156 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
157 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
158 /// update must be rejected.
160 /// This failure may also signal a failure to update the local persisted copy of one of
161 /// the channel monitor instance.
163 /// Note that even when you fail a holder commitment transaction update, you must store the
164 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
165 /// broadcasts it (e.g distributed channel-monitor deployment)
167 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
168 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
169 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
170 /// lagging behind on block processing.
174 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
175 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
176 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
178 /// Contains a developer-readable error message.
179 #[derive(Clone, Debug)]
180 pub struct MonitorUpdateError(pub &'static str);
182 /// An event to be processed by the ChannelManager.
183 #[derive(Clone, PartialEq)]
184 pub enum MonitorEvent {
185 /// A monitor event containing an HTLCUpdate.
186 HTLCEvent(HTLCUpdate),
188 /// A monitor event that the Channel's commitment transaction was broadcasted.
189 CommitmentTxBroadcasted(OutPoint),
192 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
193 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
194 /// preimage claim backward will lead to loss of funds.
196 /// [`chain::Watch`]: ../trait.Watch.html
197 #[derive(Clone, PartialEq)]
198 pub struct HTLCUpdate {
199 pub(crate) payment_hash: PaymentHash,
200 pub(crate) payment_preimage: Option<PaymentPreimage>,
201 pub(crate) source: HTLCSource
203 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
205 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
206 /// instead claiming it in its own individual transaction.
207 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
208 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
209 /// HTLC-Success transaction.
210 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
211 /// transaction confirmed (and we use it in a few more, equivalent, places).
212 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
213 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
214 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
215 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
216 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
217 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
218 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
219 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
220 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
221 /// accurate block height.
222 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
223 /// with at worst this delay, so we are not only using this value as a mercy for them but also
224 /// us as a safeguard to delay with enough time.
225 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
226 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
227 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
228 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
229 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
230 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
231 /// keeping bumping another claim tx to solve the outpoint.
232 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
233 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
234 /// refuse to accept a new HTLC.
236 /// This is used for a few separate purposes:
237 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
238 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
240 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
241 /// condition with the above), we will fail this HTLC without telling the user we received it,
242 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
243 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
245 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
246 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
248 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
249 /// in a race condition between the user connecting a block (which would fail it) and the user
250 /// providing us the preimage (which would claim it).
252 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
253 /// end up force-closing the channel on us to claim it.
254 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
256 // TODO(devrandom) replace this with HolderCommitmentTransaction
257 #[derive(Clone, PartialEq)]
258 struct HolderSignedTx {
259 /// txid of the transaction in tx, just used to make comparison faster
261 revocation_key: PublicKey,
262 a_htlc_key: PublicKey,
263 b_htlc_key: PublicKey,
264 delayed_payment_key: PublicKey,
265 per_commitment_point: PublicKey,
267 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
270 /// We use this to track counterparty commitment transactions and htlcs outputs and
271 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
273 struct CounterpartyCommitmentTransaction {
274 counterparty_delayed_payment_base_key: PublicKey,
275 counterparty_htlc_base_key: PublicKey,
276 on_counterparty_tx_csv: u16,
277 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
280 impl Writeable for CounterpartyCommitmentTransaction {
281 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
282 self.counterparty_delayed_payment_base_key.write(w)?;
283 self.counterparty_htlc_base_key.write(w)?;
284 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
285 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
286 for (ref txid, ref htlcs) in self.per_htlc.iter() {
287 w.write_all(&txid[..])?;
288 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
289 for &ref htlc in htlcs.iter() {
296 impl Readable for CounterpartyCommitmentTransaction {
297 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
298 let counterparty_commitment_transaction = {
299 let counterparty_delayed_payment_base_key = Readable::read(r)?;
300 let counterparty_htlc_base_key = Readable::read(r)?;
301 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
302 let per_htlc_len: u64 = Readable::read(r)?;
303 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
304 for _ in 0..per_htlc_len {
305 let txid: Txid = Readable::read(r)?;
306 let htlcs_count: u64 = Readable::read(r)?;
307 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
308 for _ in 0..htlcs_count {
309 let htlc = Readable::read(r)?;
312 if let Some(_) = per_htlc.insert(txid, htlcs) {
313 return Err(DecodeError::InvalidValue);
316 CounterpartyCommitmentTransaction {
317 counterparty_delayed_payment_base_key,
318 counterparty_htlc_base_key,
319 on_counterparty_tx_csv,
323 Ok(counterparty_commitment_transaction)
327 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
328 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
329 /// a new bumped one in case of lenghty confirmation delay
330 #[derive(Clone, PartialEq)]
331 pub(crate) enum InputMaterial {
333 per_commitment_point: PublicKey,
334 counterparty_delayed_payment_base_key: PublicKey,
335 counterparty_htlc_base_key: PublicKey,
336 per_commitment_key: SecretKey,
337 input_descriptor: InputDescriptors,
339 htlc: Option<HTLCOutputInCommitment>,
340 on_counterparty_tx_csv: u16,
343 per_commitment_point: PublicKey,
344 counterparty_delayed_payment_base_key: PublicKey,
345 counterparty_htlc_base_key: PublicKey,
346 preimage: Option<PaymentPreimage>,
347 htlc: HTLCOutputInCommitment
350 preimage: Option<PaymentPreimage>,
354 funding_redeemscript: Script,
358 impl Writeable for InputMaterial {
359 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
361 &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv} => {
362 writer.write_all(&[0; 1])?;
363 per_commitment_point.write(writer)?;
364 counterparty_delayed_payment_base_key.write(writer)?;
365 counterparty_htlc_base_key.write(writer)?;
366 writer.write_all(&per_commitment_key[..])?;
367 input_descriptor.write(writer)?;
368 writer.write_all(&byte_utils::be64_to_array(*amount))?;
370 on_counterparty_tx_csv.write(writer)?;
372 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
373 writer.write_all(&[1; 1])?;
374 per_commitment_point.write(writer)?;
375 counterparty_delayed_payment_base_key.write(writer)?;
376 counterparty_htlc_base_key.write(writer)?;
377 preimage.write(writer)?;
380 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
381 writer.write_all(&[2; 1])?;
382 preimage.write(writer)?;
383 writer.write_all(&byte_utils::be64_to_array(*amount))?;
385 &InputMaterial::Funding { ref funding_redeemscript } => {
386 writer.write_all(&[3; 1])?;
387 funding_redeemscript.write(writer)?;
394 impl Readable for InputMaterial {
395 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
396 let input_material = match <u8 as Readable>::read(reader)? {
398 let per_commitment_point = Readable::read(reader)?;
399 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
400 let counterparty_htlc_base_key = Readable::read(reader)?;
401 let per_commitment_key = Readable::read(reader)?;
402 let input_descriptor = Readable::read(reader)?;
403 let amount = Readable::read(reader)?;
404 let htlc = Readable::read(reader)?;
405 let on_counterparty_tx_csv = Readable::read(reader)?;
406 InputMaterial::Revoked {
407 per_commitment_point,
408 counterparty_delayed_payment_base_key,
409 counterparty_htlc_base_key,
414 on_counterparty_tx_csv
418 let per_commitment_point = Readable::read(reader)?;
419 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
420 let counterparty_htlc_base_key = Readable::read(reader)?;
421 let preimage = Readable::read(reader)?;
422 let htlc = Readable::read(reader)?;
423 InputMaterial::CounterpartyHTLC {
424 per_commitment_point,
425 counterparty_delayed_payment_base_key,
426 counterparty_htlc_base_key,
432 let preimage = Readable::read(reader)?;
433 let amount = Readable::read(reader)?;
434 InputMaterial::HolderHTLC {
440 InputMaterial::Funding {
441 funding_redeemscript: Readable::read(reader)?,
444 _ => return Err(DecodeError::InvalidValue),
450 /// ClaimRequest is a descriptor structure to communicate between detection
451 /// and reaction module. They are generated by ChannelMonitor while parsing
452 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
453 /// is responsible for opportunistic aggregation, selecting and enforcing
454 /// bumping logic, building and signing transactions.
455 pub(crate) struct ClaimRequest {
456 // Block height before which claiming is exclusive to one party,
457 // after reaching it, claiming may be contentious.
458 pub(crate) absolute_timelock: u32,
459 // Timeout tx must have nLocktime set which means aggregating multiple
460 // ones must take the higher nLocktime among them to satisfy all of them.
461 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
462 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
463 // Do simplify we mark them as non-aggregable.
464 pub(crate) aggregable: bool,
465 // Basic bitcoin outpoint (txid, vout)
466 pub(crate) outpoint: BitcoinOutPoint,
467 // Following outpoint type, set of data needed to generate transaction digest
468 // and satisfy witness program.
469 pub(crate) witness_data: InputMaterial
472 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
473 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
474 #[derive(Clone, PartialEq)]
476 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
477 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
478 /// only win from it, so it's never an OnchainEvent
480 htlc_update: (HTLCSource, PaymentHash),
483 descriptor: SpendableOutputDescriptor,
487 const SERIALIZATION_VERSION: u8 = 1;
488 const MIN_SERIALIZATION_VERSION: u8 = 1;
490 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
492 pub(crate) enum ChannelMonitorUpdateStep {
493 LatestHolderCommitmentTXInfo {
494 commitment_tx: HolderCommitmentTransaction,
495 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
497 LatestCounterpartyCommitmentTXInfo {
498 commitment_txid: Txid,
499 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
500 commitment_number: u64,
501 their_revocation_point: PublicKey,
504 payment_preimage: PaymentPreimage,
510 /// Used to indicate that the no future updates will occur, and likely that the latest holder
511 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
513 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
514 /// think we've fallen behind!
515 should_broadcast: bool,
519 impl Writeable for ChannelMonitorUpdateStep {
520 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
522 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
524 commitment_tx.write(w)?;
525 (htlc_outputs.len() as u64).write(w)?;
526 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
532 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
534 commitment_txid.write(w)?;
535 commitment_number.write(w)?;
536 their_revocation_point.write(w)?;
537 (htlc_outputs.len() as u64).write(w)?;
538 for &(ref output, ref source) in htlc_outputs.iter() {
540 source.as_ref().map(|b| b.as_ref()).write(w)?;
543 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
545 payment_preimage.write(w)?;
547 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
552 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
554 should_broadcast.write(w)?;
560 impl Readable for ChannelMonitorUpdateStep {
561 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
562 match Readable::read(r)? {
564 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
565 commitment_tx: Readable::read(r)?,
567 let len: u64 = Readable::read(r)?;
568 let mut res = Vec::new();
570 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
577 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
578 commitment_txid: Readable::read(r)?,
579 commitment_number: Readable::read(r)?,
580 their_revocation_point: Readable::read(r)?,
582 let len: u64 = Readable::read(r)?;
583 let mut res = Vec::new();
585 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
592 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
593 payment_preimage: Readable::read(r)?,
597 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
598 idx: Readable::read(r)?,
599 secret: Readable::read(r)?,
603 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
604 should_broadcast: Readable::read(r)?
607 _ => Err(DecodeError::InvalidValue),
612 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
613 /// on-chain transactions to ensure no loss of funds occurs.
615 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
616 /// information and are actively monitoring the chain.
618 /// Pending Events or updated HTLCs which have not yet been read out by
619 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
620 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
621 /// gotten are fully handled before re-serializing the new state.
623 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
624 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
625 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
626 /// returned block hash and the the current chain and then reconnecting blocks to get to the
627 /// best chain) upon deserializing the object!
628 pub struct ChannelMonitor<Signer: Sign> {
630 pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
632 inner: Mutex<ChannelMonitorImpl<Signer>>,
635 pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
636 latest_update_id: u64,
637 commitment_transaction_number_obscure_factor: u64,
639 destination_script: Script,
640 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
641 counterparty_payment_script: Script,
642 shutdown_script: Script,
644 channel_keys_id: [u8; 32],
645 holder_revocation_basepoint: PublicKey,
646 funding_info: (OutPoint, Script),
647 current_counterparty_commitment_txid: Option<Txid>,
648 prev_counterparty_commitment_txid: Option<Txid>,
650 counterparty_tx_cache: CounterpartyCommitmentTransaction,
651 funding_redeemscript: Script,
652 channel_value_satoshis: u64,
653 // first is the idx of the first of the two revocation points
654 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
656 on_holder_tx_csv: u16,
658 commitment_secrets: CounterpartyCommitmentSecrets,
659 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
660 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
661 /// Nor can we figure out their commitment numbers without the commitment transaction they are
662 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
663 /// commitment transactions which we find on-chain, mapping them to the commitment number which
664 /// can be used to derive the revocation key and claim the transactions.
665 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
666 /// Cache used to make pruning of payment_preimages faster.
667 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
668 /// counterparty transactions (ie should remain pretty small).
669 /// Serialized to disk but should generally not be sent to Watchtowers.
670 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
672 // We store two holder commitment transactions to avoid any race conditions where we may update
673 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
674 // various monitors for one channel being out of sync, and us broadcasting a holder
675 // transaction for which we have deleted claim information on some watchtowers.
676 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
677 current_holder_commitment_tx: HolderSignedTx,
679 // Used just for ChannelManager to make sure it has the latest channel data during
681 current_counterparty_commitment_number: u64,
682 // Used just for ChannelManager to make sure it has the latest channel data during
684 current_holder_commitment_number: u64,
686 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
688 pending_monitor_events: Vec<MonitorEvent>,
689 pending_events: Vec<Event>,
691 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
692 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
693 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
694 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
696 // If we get serialized out and re-read, we need to make sure that the chain monitoring
697 // interface knows about the TXOs that we want to be notified of spends of. We could probably
698 // be smart and derive them from the above storage fields, but its much simpler and more
699 // Obviously Correct (tm) if we just keep track of them explicitly.
700 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
703 pub onchain_tx_handler: OnchainTxHandler<Signer>,
705 onchain_tx_handler: OnchainTxHandler<Signer>,
707 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
708 // channel has been force-closed. After this is set, no further holder commitment transaction
709 // updates may occur, and we panic!() if one is provided.
710 lockdown_from_offchain: bool,
712 // Set once we've signed a holder commitment transaction and handed it over to our
713 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
714 // may occur, and we fail any such monitor updates.
716 // In case of update rejection due to a locally already signed commitment transaction, we
717 // nevertheless store update content to track in case of concurrent broadcast by another
718 // remote monitor out-of-order with regards to the block view.
719 holder_tx_signed: bool,
721 // We simply modify last_block_hash in Channel's block_connected so that serialization is
722 // consistent but hopefully the users' copy handles block_connected in a consistent way.
723 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
724 // their last_block_hash from its state and not based on updated copies that didn't run through
725 // the full block_connected).
726 last_block_hash: BlockHash,
727 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
730 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
731 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
732 /// underlying object
733 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
734 fn eq(&self, other: &Self) -> bool {
735 let inner = self.inner.lock().unwrap();
736 let other = other.inner.lock().unwrap();
741 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
742 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
743 /// underlying object
744 impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
745 fn eq(&self, other: &Self) -> bool {
746 if self.latest_update_id != other.latest_update_id ||
747 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
748 self.destination_script != other.destination_script ||
749 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
750 self.counterparty_payment_script != other.counterparty_payment_script ||
751 self.channel_keys_id != other.channel_keys_id ||
752 self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
753 self.funding_info != other.funding_info ||
754 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
755 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
756 self.counterparty_tx_cache != other.counterparty_tx_cache ||
757 self.funding_redeemscript != other.funding_redeemscript ||
758 self.channel_value_satoshis != other.channel_value_satoshis ||
759 self.their_cur_revocation_points != other.their_cur_revocation_points ||
760 self.on_holder_tx_csv != other.on_holder_tx_csv ||
761 self.commitment_secrets != other.commitment_secrets ||
762 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
763 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
764 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
765 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
766 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
767 self.current_holder_commitment_number != other.current_holder_commitment_number ||
768 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
769 self.payment_preimages != other.payment_preimages ||
770 self.pending_monitor_events != other.pending_monitor_events ||
771 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
772 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
773 self.outputs_to_watch != other.outputs_to_watch ||
774 self.lockdown_from_offchain != other.lockdown_from_offchain ||
775 self.holder_tx_signed != other.holder_tx_signed
784 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
785 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
786 //TODO: We still write out all the serialization here manually instead of using the fancy
787 //serialization framework we have, we should migrate things over to it.
788 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
789 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
791 self.inner.lock().unwrap().write(writer)
795 impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
796 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
797 self.latest_update_id.write(writer)?;
799 // Set in initial Channel-object creation, so should always be set by now:
800 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
802 self.destination_script.write(writer)?;
803 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
804 writer.write_all(&[0; 1])?;
805 broadcasted_holder_revokable_script.0.write(writer)?;
806 broadcasted_holder_revokable_script.1.write(writer)?;
807 broadcasted_holder_revokable_script.2.write(writer)?;
809 writer.write_all(&[1; 1])?;
812 self.counterparty_payment_script.write(writer)?;
813 self.shutdown_script.write(writer)?;
815 self.channel_keys_id.write(writer)?;
816 self.holder_revocation_basepoint.write(writer)?;
817 writer.write_all(&self.funding_info.0.txid[..])?;
818 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
819 self.funding_info.1.write(writer)?;
820 self.current_counterparty_commitment_txid.write(writer)?;
821 self.prev_counterparty_commitment_txid.write(writer)?;
823 self.counterparty_tx_cache.write(writer)?;
824 self.funding_redeemscript.write(writer)?;
825 self.channel_value_satoshis.write(writer)?;
827 match self.their_cur_revocation_points {
828 Some((idx, pubkey, second_option)) => {
829 writer.write_all(&byte_utils::be48_to_array(idx))?;
830 writer.write_all(&pubkey.serialize())?;
831 match second_option {
832 Some(second_pubkey) => {
833 writer.write_all(&second_pubkey.serialize())?;
836 writer.write_all(&[0; 33])?;
841 writer.write_all(&byte_utils::be48_to_array(0))?;
845 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
847 self.commitment_secrets.write(writer)?;
849 macro_rules! serialize_htlc_in_commitment {
850 ($htlc_output: expr) => {
851 writer.write_all(&[$htlc_output.offered as u8; 1])?;
852 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
853 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
854 writer.write_all(&$htlc_output.payment_hash.0[..])?;
855 $htlc_output.transaction_output_index.write(writer)?;
859 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
860 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
861 writer.write_all(&txid[..])?;
862 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
863 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
864 serialize_htlc_in_commitment!(htlc_output);
865 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
869 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
870 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
871 writer.write_all(&txid[..])?;
872 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
875 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
876 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
877 writer.write_all(&payment_hash.0[..])?;
878 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
881 macro_rules! serialize_holder_tx {
882 ($holder_tx: expr) => {
883 $holder_tx.txid.write(writer)?;
884 writer.write_all(&$holder_tx.revocation_key.serialize())?;
885 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
886 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
887 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
888 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
890 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
891 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
892 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
893 serialize_htlc_in_commitment!(htlc_output);
894 if let &Some(ref their_sig) = sig {
896 writer.write_all(&their_sig.serialize_compact())?;
900 htlc_source.write(writer)?;
905 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
906 writer.write_all(&[1; 1])?;
907 serialize_holder_tx!(prev_holder_tx);
909 writer.write_all(&[0; 1])?;
912 serialize_holder_tx!(self.current_holder_commitment_tx);
914 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
915 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
917 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
918 for payment_preimage in self.payment_preimages.values() {
919 writer.write_all(&payment_preimage.0[..])?;
922 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
923 for event in self.pending_monitor_events.iter() {
925 MonitorEvent::HTLCEvent(upd) => {
929 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
933 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
934 for event in self.pending_events.iter() {
935 event.write(writer)?;
938 self.last_block_hash.write(writer)?;
940 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
941 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
942 writer.write_all(&byte_utils::be32_to_array(**target))?;
943 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
944 for ev in events.iter() {
946 OnchainEvent::HTLCUpdate { ref htlc_update } => {
948 htlc_update.0.write(writer)?;
949 htlc_update.1.write(writer)?;
951 OnchainEvent::MaturingOutput { ref descriptor } => {
953 descriptor.write(writer)?;
959 (self.outputs_to_watch.len() as u64).write(writer)?;
960 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
962 (idx_scripts.len() as u64).write(writer)?;
963 for (idx, script) in idx_scripts.iter() {
965 script.write(writer)?;
968 self.onchain_tx_handler.write(writer)?;
970 self.lockdown_from_offchain.write(writer)?;
971 self.holder_tx_signed.write(writer)?;
977 impl<Signer: Sign> ChannelMonitor<Signer> {
978 pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_pubkey: &PublicKey,
979 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
980 channel_parameters: &ChannelTransactionParameters,
981 funding_redeemscript: Script, channel_value_satoshis: u64,
982 commitment_transaction_number_obscure_factor: u64,
983 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<Signer> {
985 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
986 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
987 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
988 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
989 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
991 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
992 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
993 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
994 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
996 let channel_keys_id = keys.channel_keys_id();
997 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
999 // block for Rust 1.34 compat
1000 let (holder_commitment_tx, current_holder_commitment_number) = {
1001 let trusted_tx = initial_holder_commitment_tx.trust();
1002 let txid = trusted_tx.txid();
1004 let tx_keys = trusted_tx.keys();
1005 let holder_commitment_tx = HolderSignedTx {
1007 revocation_key: tx_keys.revocation_key,
1008 a_htlc_key: tx_keys.broadcaster_htlc_key,
1009 b_htlc_key: tx_keys.countersignatory_htlc_key,
1010 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1011 per_commitment_point: tx_keys.per_commitment_point,
1012 feerate_per_kw: trusted_tx.feerate_per_kw(),
1013 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1015 (holder_commitment_tx, trusted_tx.commitment_number())
1018 let onchain_tx_handler =
1019 OnchainTxHandler::new(destination_script.clone(), keys,
1020 channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
1022 let mut outputs_to_watch = HashMap::new();
1023 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1026 inner: Mutex::new(ChannelMonitorImpl {
1027 latest_update_id: 0,
1028 commitment_transaction_number_obscure_factor,
1030 destination_script: destination_script.clone(),
1031 broadcasted_holder_revokable_script: None,
1032 counterparty_payment_script,
1036 holder_revocation_basepoint,
1038 current_counterparty_commitment_txid: None,
1039 prev_counterparty_commitment_txid: None,
1041 counterparty_tx_cache,
1042 funding_redeemscript,
1043 channel_value_satoshis,
1044 their_cur_revocation_points: None,
1046 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1048 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1049 counterparty_claimable_outpoints: HashMap::new(),
1050 counterparty_commitment_txn_on_chain: HashMap::new(),
1051 counterparty_hash_commitment_number: HashMap::new(),
1053 prev_holder_signed_commitment_tx: None,
1054 current_holder_commitment_tx: holder_commitment_tx,
1055 current_counterparty_commitment_number: 1 << 48,
1056 current_holder_commitment_number,
1058 payment_preimages: HashMap::new(),
1059 pending_monitor_events: Vec::new(),
1060 pending_events: Vec::new(),
1062 onchain_events_waiting_threshold_conf: HashMap::new(),
1067 lockdown_from_offchain: false,
1068 holder_tx_signed: false,
1070 last_block_hash: Default::default(),
1077 fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1078 self.inner.lock().unwrap().provide_secret(idx, secret)
1081 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1082 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1083 /// possibly future revocation/preimage information) to claim outputs where possible.
1084 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1085 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1088 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1089 commitment_number: u64,
1090 their_revocation_point: PublicKey,
1092 ) where L::Target: Logger {
1093 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1094 txid, htlc_outputs, commitment_number, their_revocation_point, logger)
1098 fn provide_latest_holder_commitment_tx(
1100 holder_commitment_tx: HolderCommitmentTransaction,
1101 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1102 ) -> Result<(), MonitorUpdateError> {
1103 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
1104 holder_commitment_tx, htlc_outputs)
1108 pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1110 payment_hash: &PaymentHash,
1111 payment_preimage: &PaymentPreimage,
1116 B::Target: BroadcasterInterface,
1117 F::Target: FeeEstimator,
1120 self.inner.lock().unwrap().provide_payment_preimage(
1121 payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1124 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1129 B::Target: BroadcasterInterface,
1132 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
1135 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1138 /// panics if the given update is not the next update by update_id.
1139 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1141 updates: &ChannelMonitorUpdate,
1145 ) -> Result<(), MonitorUpdateError>
1147 B::Target: BroadcasterInterface,
1148 F::Target: FeeEstimator,
1151 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1154 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1156 pub fn get_latest_update_id(&self) -> u64 {
1157 self.inner.lock().unwrap().get_latest_update_id()
1160 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1161 pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1162 self.inner.lock().unwrap().get_funding_txo().clone()
1165 /// Gets a list of txids, with their output scripts (in the order they appear in the
1166 /// transaction), which we must learn about spends of via block_connected().
1168 /// (C-not exported) because we have no HashMap bindings
1169 pub fn get_outputs_to_watch(&self) -> HashMap<Txid, Vec<(u32, Script)>> {
1170 self.inner.lock().unwrap().get_outputs_to_watch().clone()
1173 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1174 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1176 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
1177 pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1178 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1181 /// Gets the list of pending events which were generated by previous actions, clearing the list
1184 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1185 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1186 /// no internal locking in ChannelMonitors.
1187 pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1188 self.inner.lock().unwrap().get_and_clear_pending_events()
1191 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1192 self.inner.lock().unwrap().get_min_seen_secret()
1195 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1196 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1199 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1200 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1203 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1204 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1205 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1206 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1207 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1208 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1209 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1210 /// out-of-band the other node operator to coordinate with him if option is available to you.
1211 /// In any-case, choice is up to the user.
1212 pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1213 where L::Target: Logger {
1214 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1217 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1218 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1219 /// revoked commitment transaction.
1220 #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1221 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1222 where L::Target: Logger {
1223 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1226 /// Processes transactions in a newly connected block, which may result in any of the following:
1227 /// - update the monitor's state against resolved HTLCs
1228 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1229 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1230 /// - detect settled outputs for later spending
1231 /// - schedule and bump any in-flight claims
1233 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1234 /// [`get_outputs_to_watch`].
1236 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1237 pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1239 header: &BlockHeader,
1240 txdata: &TransactionData,
1245 ) -> Vec<(Txid, Vec<(u32, TxOut)>)>
1247 B::Target: BroadcasterInterface,
1248 F::Target: FeeEstimator,
1251 self.inner.lock().unwrap().block_connected(
1252 header, txdata, height, broadcaster, fee_estimator, logger)
1255 /// Determines if the disconnected block contained any transactions of interest and updates
1257 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1259 header: &BlockHeader,
1265 B::Target: BroadcasterInterface,
1266 F::Target: FeeEstimator,
1269 self.inner.lock().unwrap().block_disconnected(
1270 header, height, broadcaster, fee_estimator, logger)
1274 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1275 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1276 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1277 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1278 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1279 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1280 return Err(MonitorUpdateError("Previous secret did not match new one"));
1283 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1284 // events for now-revoked/fulfilled HTLCs.
1285 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1286 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1291 if !self.payment_preimages.is_empty() {
1292 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1293 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1294 let min_idx = self.get_min_seen_secret();
1295 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1297 self.payment_preimages.retain(|&k, _| {
1298 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1299 if k == htlc.payment_hash {
1303 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1304 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1305 if k == htlc.payment_hash {
1310 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1317 counterparty_hash_commitment_number.remove(&k);
1326 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1327 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1328 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1329 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1331 for &(ref htlc, _) in &htlc_outputs {
1332 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1335 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1336 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1337 self.current_counterparty_commitment_txid = Some(txid);
1338 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1339 self.current_counterparty_commitment_number = commitment_number;
1340 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1341 match self.their_cur_revocation_points {
1342 Some(old_points) => {
1343 if old_points.0 == commitment_number + 1 {
1344 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1345 } else if old_points.0 == commitment_number + 2 {
1346 if let Some(old_second_point) = old_points.2 {
1347 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1349 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1352 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1356 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1359 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1360 for htlc in htlc_outputs {
1361 if htlc.0.transaction_output_index.is_some() {
1365 self.counterparty_tx_cache.per_htlc.insert(txid, htlcs);
1368 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1369 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1370 /// is important that any clones of this channel monitor (including remote clones) by kept
1371 /// up-to-date as our holder commitment transaction is updated.
1372 /// Panics if set_on_holder_tx_csv has never been called.
1373 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1374 // block for Rust 1.34 compat
1375 let mut new_holder_commitment_tx = {
1376 let trusted_tx = holder_commitment_tx.trust();
1377 let txid = trusted_tx.txid();
1378 let tx_keys = trusted_tx.keys();
1379 self.current_holder_commitment_number = trusted_tx.commitment_number();
1382 revocation_key: tx_keys.revocation_key,
1383 a_htlc_key: tx_keys.broadcaster_htlc_key,
1384 b_htlc_key: tx_keys.countersignatory_htlc_key,
1385 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1386 per_commitment_point: tx_keys.per_commitment_point,
1387 feerate_per_kw: trusted_tx.feerate_per_kw(),
1391 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1392 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1393 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1394 if self.holder_tx_signed {
1395 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1400 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1401 /// commitment_tx_infos which contain the payment hash have been revoked.
1402 fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
1403 where B::Target: BroadcasterInterface,
1404 F::Target: FeeEstimator,
1407 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1409 // If the channel is force closed, try to claim the output from this preimage.
1410 // First check if a counterparty commitment transaction has been broadcasted:
1411 macro_rules! claim_htlcs {
1412 ($commitment_number: expr, $txid: expr) => {
1413 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1414 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, None, broadcaster, fee_estimator, logger);
1417 if let Some(txid) = self.current_counterparty_commitment_txid {
1418 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1419 claim_htlcs!(*commitment_number, txid);
1423 if let Some(txid) = self.prev_counterparty_commitment_txid {
1424 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1425 claim_htlcs!(*commitment_number, txid);
1430 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1431 // claiming the HTLC output from each of the holder commitment transactions.
1432 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1433 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1434 // holder commitment transactions.
1435 if self.broadcasted_holder_revokable_script.is_some() {
1436 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1437 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1438 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1439 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx);
1440 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1445 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1446 where B::Target: BroadcasterInterface,
1449 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1450 broadcaster.broadcast_transaction(tx);
1452 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1455 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1456 where B::Target: BroadcasterInterface,
1457 F::Target: FeeEstimator,
1460 // ChannelMonitor updates may be applied after force close if we receive a
1461 // preimage for a broadcasted commitment transaction HTLC output that we'd
1462 // like to claim on-chain. If this is the case, we no longer have guaranteed
1463 // access to the monitor's update ID, so we use a sentinel value instead.
1464 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1465 match updates.updates[0] {
1466 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1467 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1469 assert_eq!(updates.updates.len(), 1);
1470 } else if self.latest_update_id + 1 != updates.update_id {
1471 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1473 for update in updates.updates.iter() {
1475 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1476 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1477 if self.lockdown_from_offchain { panic!(); }
1478 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1480 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1481 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1482 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1484 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1485 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1486 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1488 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1489 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1490 self.provide_secret(*idx, *secret)?
1492 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1493 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1494 self.lockdown_from_offchain = true;
1495 if *should_broadcast {
1496 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1498 log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
1503 self.latest_update_id = updates.update_id;
1507 pub fn get_latest_update_id(&self) -> u64 {
1508 self.latest_update_id
1511 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1515 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1516 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1517 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1518 // its trivial to do, double-check that here.
1519 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1520 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1522 &self.outputs_to_watch
1525 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1526 let mut ret = Vec::new();
1527 mem::swap(&mut ret, &mut self.pending_monitor_events);
1531 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1532 let mut ret = Vec::new();
1533 mem::swap(&mut ret, &mut self.pending_events);
1537 /// Can only fail if idx is < get_min_seen_secret
1538 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1539 self.commitment_secrets.get_secret(idx)
1542 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1543 self.commitment_secrets.get_min_seen_secret()
1546 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1547 self.current_counterparty_commitment_number
1550 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1551 self.current_holder_commitment_number
1554 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1555 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1556 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1557 /// HTLC-Success/HTLC-Timeout transactions.
1558 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1559 /// revoked counterparty commitment tx
1560 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<(u32, TxOut)>)) where L::Target: Logger {
1561 // Most secp and related errors trying to create keys means we have no hope of constructing
1562 // a spend transaction...so we return no transactions to broadcast
1563 let mut claimable_outpoints = Vec::new();
1564 let mut watch_outputs = Vec::new();
1566 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1567 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1569 macro_rules! ignore_error {
1570 ( $thing : expr ) => {
1573 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1578 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);
1579 if commitment_number >= self.get_min_seen_secret() {
1580 let secret = self.get_secret(commitment_number).unwrap();
1581 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1582 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1583 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
1584 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_tx_cache.counterparty_delayed_payment_base_key));
1586 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1587 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1589 // First, process non-htlc outputs (to_holder & to_counterparty)
1590 for (idx, outp) in tx.output.iter().enumerate() {
1591 if outp.script_pubkey == revokeable_p2wsh {
1592 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: outp.value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1593 claimable_outpoints.push(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 }, witness_data});
1597 // Then, try to find revoked htlc outputs
1598 if let Some(ref per_commitment_data) = per_commitment_option {
1599 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1600 if let Some(transaction_output_index) = htlc.transaction_output_index {
1601 if transaction_output_index as usize >= tx.output.len() ||
1602 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1603 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1605 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }, amount: tx.output[transaction_output_index as usize].value, htlc: Some(htlc.clone()), on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv};
1606 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1611 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1612 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1613 // We're definitely a counterparty commitment transaction!
1614 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1615 for (idx, outp) in tx.output.iter().enumerate() {
1616 watch_outputs.push((idx as u32, outp.clone()));
1618 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1620 macro_rules! check_htlc_fails {
1621 ($txid: expr, $commitment_tx: expr) => {
1622 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1623 for &(ref htlc, ref source_option) in outpoints.iter() {
1624 if let &Some(ref source) = source_option {
1625 log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1626 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1627 hash_map::Entry::Occupied(mut entry) => {
1628 let e = entry.get_mut();
1629 e.retain(|ref event| {
1631 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1632 return htlc_update.0 != **source
1637 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1639 hash_map::Entry::Vacant(entry) => {
1640 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1648 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1649 check_htlc_fails!(txid, "current");
1651 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1652 check_htlc_fails!(txid, "counterparty");
1654 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1656 } else if let Some(per_commitment_data) = per_commitment_option {
1657 // While this isn't useful yet, there is a potential race where if a counterparty
1658 // revokes a state at the same time as the commitment transaction for that state is
1659 // confirmed, and the watchtower receives the block before the user, the user could
1660 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1661 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1662 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1664 for (idx, outp) in tx.output.iter().enumerate() {
1665 watch_outputs.push((idx as u32, outp.clone()));
1667 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1669 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1671 macro_rules! check_htlc_fails {
1672 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1673 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1674 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1675 if let &Some(ref source) = source_option {
1676 // Check if the HTLC is present in the commitment transaction that was
1677 // broadcast, but not if it was below the dust limit, which we should
1678 // fail backwards immediately as there is no way for us to learn the
1679 // payment_preimage.
1680 // Note that if the dust limit were allowed to change between
1681 // commitment transactions we'd want to be check whether *any*
1682 // broadcastable commitment transaction has the HTLC in it, but it
1683 // cannot currently change after channel initialization, so we don't
1685 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1686 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1690 log_trace!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of counterparty commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1691 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1692 hash_map::Entry::Occupied(mut entry) => {
1693 let e = entry.get_mut();
1694 e.retain(|ref event| {
1696 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1697 return htlc_update.0 != **source
1702 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1704 hash_map::Entry::Vacant(entry) => {
1705 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1713 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1714 check_htlc_fails!(txid, "current", 'current_loop);
1716 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1717 check_htlc_fails!(txid, "previous", 'prev_loop);
1720 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
1721 for req in htlc_claim_reqs {
1722 claimable_outpoints.push(req);
1726 (claimable_outpoints, (commitment_txid, watch_outputs))
1729 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<ClaimRequest> {
1730 let mut claims = Vec::new();
1731 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
1732 if let Some(revocation_points) = self.their_cur_revocation_points {
1733 let revocation_point_option =
1734 // If the counterparty commitment tx is the latest valid state, use their latest
1735 // per-commitment point
1736 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1737 else if let Some(point) = revocation_points.2.as_ref() {
1738 // If counterparty commitment tx is the state previous to the latest valid state, use
1739 // their previous per-commitment point (non-atomicity of revocation means it's valid for
1740 // them to temporarily have two valid commitment txns from our viewpoint)
1741 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1743 if let Some(revocation_point) = revocation_point_option {
1744 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
1745 if let Some(transaction_output_index) = htlc.transaction_output_index {
1746 if let Some(transaction) = tx {
1747 if transaction_output_index as usize >= transaction.output.len() ||
1748 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1749 return claims; // Corrupted per_commitment_data, fuck this user
1754 if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) {
1758 let aggregable = if !htlc.offered { false } else { true };
1759 if preimage.is_some() || !htlc.offered {
1760 let witness_data = InputMaterial::CounterpartyHTLC { per_commitment_point: *revocation_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, preimage, htlc: htlc.clone() };
1761 claims.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1771 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1772 fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<(u32, TxOut)>)>) where L::Target: Logger {
1773 let htlc_txid = tx.txid();
1774 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1775 return (Vec::new(), None)
1778 macro_rules! ignore_error {
1779 ( $thing : expr ) => {
1782 Err(_) => return (Vec::new(), None)
1787 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1788 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1789 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1791 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1792 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv };
1793 let claimable_outpoints = vec!(ClaimRequest { absolute_timelock: height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, aggregable: true, outpoint: BitcoinOutPoint { txid: htlc_txid, vout: 0}, witness_data });
1794 let outputs = vec![(0, tx.output[0].clone())];
1795 (claimable_outpoints, Some((htlc_txid, outputs)))
1798 // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can
1799 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1800 // script so we can detect whether a holder transaction has been seen on-chain.
1801 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Option<(Script, PublicKey, PublicKey)>) {
1802 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1804 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1805 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1807 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1808 if let Some(transaction_output_index) = htlc.transaction_output_index {
1809 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1810 witness_data: InputMaterial::HolderHTLC {
1811 preimage: if !htlc.offered {
1812 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1813 Some(preimage.clone())
1815 // We can't build an HTLC-Success transaction without the preimage
1819 amount: htlc.amount_msat,
1824 (claim_requests, broadcasted_holder_revokable_script)
1827 // Returns holder HTLC outputs to watch and react to in case of spending.
1828 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1829 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1830 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1831 if let Some(transaction_output_index) = htlc.transaction_output_index {
1832 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1838 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1839 /// revoked using data in holder_claimable_outpoints.
1840 /// Should not be used if check_spend_revoked_transaction succeeds.
1841 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<(u32, TxOut)>)) where L::Target: Logger {
1842 let commitment_txid = tx.txid();
1843 let mut claim_requests = Vec::new();
1844 let mut watch_outputs = Vec::new();
1846 macro_rules! wait_threshold_conf {
1847 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1848 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1849 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1850 hash_map::Entry::Occupied(mut entry) => {
1851 let e = entry.get_mut();
1852 e.retain(|ref event| {
1854 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1855 return htlc_update.0 != $source
1860 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1862 hash_map::Entry::Vacant(entry) => {
1863 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1869 macro_rules! append_onchain_update {
1870 ($updates: expr, $to_watch: expr) => {
1871 claim_requests = $updates.0;
1872 self.broadcasted_holder_revokable_script = $updates.1;
1873 watch_outputs.append(&mut $to_watch);
1877 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1878 let mut is_holder_tx = false;
1880 if self.current_holder_commitment_tx.txid == commitment_txid {
1881 is_holder_tx = true;
1882 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1883 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1884 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1885 append_onchain_update!(res, to_watch);
1886 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1887 if holder_tx.txid == commitment_txid {
1888 is_holder_tx = true;
1889 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1890 let res = self.get_broadcasted_holder_claims(holder_tx);
1891 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1892 append_onchain_update!(res, to_watch);
1896 macro_rules! fail_dust_htlcs_after_threshold_conf {
1897 ($holder_tx: expr) => {
1898 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1899 if htlc.transaction_output_index.is_none() {
1900 if let &Some(ref source) = source {
1901 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1909 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1910 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1911 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1915 (claim_requests, (commitment_txid, watch_outputs))
1918 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1919 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1920 self.holder_tx_signed = true;
1921 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
1922 let txid = commitment_tx.txid();
1923 let mut res = vec![commitment_tx];
1924 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1925 if let Some(vout) = htlc.0.transaction_output_index {
1926 let preimage = if !htlc.0.offered {
1927 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1928 // We can't build an HTLC-Success transaction without the preimage
1932 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1933 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1938 // 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.
1939 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1943 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1944 fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1945 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1946 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
1947 let txid = commitment_tx.txid();
1948 let mut res = vec![commitment_tx];
1949 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1950 if let Some(vout) = htlc.0.transaction_output_index {
1951 let preimage = if !htlc.0.offered {
1952 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1953 // We can't build an HTLC-Success transaction without the preimage
1957 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1958 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1966 pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<(u32, TxOut)>)>
1967 where B::Target: BroadcasterInterface,
1968 F::Target: FeeEstimator,
1971 let txn_matched = self.filter_block(txdata);
1972 for tx in &txn_matched {
1973 let mut output_val = 0;
1974 for out in tx.output.iter() {
1975 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1976 output_val += out.value;
1977 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1981 let block_hash = header.block_hash();
1982 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1984 let mut watch_outputs = Vec::new();
1985 let mut claimable_outpoints = Vec::new();
1986 for tx in &txn_matched {
1987 if tx.input.len() == 1 {
1988 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1989 // commitment transactions and HTLC transactions will all only ever have one input,
1990 // which is an easy way to filter out any potential non-matching txn for lazy
1992 let prevout = &tx.input[0].previous_output;
1993 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1994 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1995 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1996 if !new_outputs.1.is_empty() {
1997 watch_outputs.push(new_outputs);
1999 if new_outpoints.is_empty() {
2000 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
2001 if !new_outputs.1.is_empty() {
2002 watch_outputs.push(new_outputs);
2004 claimable_outpoints.append(&mut new_outpoints);
2006 claimable_outpoints.append(&mut new_outpoints);
2009 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2010 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2011 claimable_outpoints.append(&mut new_outpoints);
2012 if let Some(new_outputs) = new_outputs_option {
2013 watch_outputs.push(new_outputs);
2018 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2019 // can also be resolved in a few other ways which can have more than one output. Thus,
2020 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2021 self.is_resolving_htlc_output(&tx, height, &logger);
2023 self.is_paying_spendable_output(&tx, height, &logger);
2025 let should_broadcast = self.would_broadcast_at_height(height, &logger);
2026 if should_broadcast {
2027 claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.funding_info.0.txid.clone(), vout: self.funding_info.0.index as u32 }, witness_data: InputMaterial::Funding { funding_redeemscript: self.funding_redeemscript.clone() }});
2029 if should_broadcast {
2030 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
2031 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2032 self.holder_tx_signed = true;
2033 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
2034 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2035 if !new_outputs.is_empty() {
2036 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2038 claimable_outpoints.append(&mut new_outpoints);
2040 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
2043 OnchainEvent::HTLCUpdate { htlc_update } => {
2044 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
2045 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2046 payment_hash: htlc_update.1,
2047 payment_preimage: None,
2048 source: htlc_update.0,
2051 OnchainEvent::MaturingOutput { descriptor } => {
2052 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2053 self.pending_events.push(Event::SpendableOutputs {
2054 outputs: vec![descriptor]
2061 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
2062 self.last_block_hash = block_hash;
2064 // Determine new outputs to watch by comparing against previously known outputs to watch,
2065 // updating the latter in the process.
2066 watch_outputs.retain(|&(ref txid, ref txouts)| {
2067 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2068 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2072 // If we see a transaction for which we registered outputs previously,
2073 // make sure the registered scriptpubkey at the expected index match
2074 // the actual transaction output one. We failed this case before #653.
2075 for tx in &txn_matched {
2076 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2077 for idx_and_script in outputs.iter() {
2078 assert!((idx_and_script.0 as usize) < tx.output.len());
2079 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2087 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2088 where B::Target: BroadcasterInterface,
2089 F::Target: FeeEstimator,
2092 let block_hash = header.block_hash();
2093 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
2095 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
2097 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2098 //- maturing spendable output has transaction paying us has been disconnected
2101 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2103 self.last_block_hash = block_hash;
2106 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2107 /// transactions thereof.
2108 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2109 let mut matched_txn = HashSet::new();
2110 txdata.iter().filter(|&&(_, tx)| {
2111 let mut matches = self.spends_watched_output(tx);
2112 for input in tx.input.iter() {
2113 if matches { break; }
2114 if matched_txn.contains(&input.previous_output.txid) {
2119 matched_txn.insert(tx.txid());
2122 }).map(|(_, tx)| *tx).collect()
2125 /// Checks if a given transaction spends any watched outputs.
2126 fn spends_watched_output(&self, tx: &Transaction) -> bool {
2127 for input in tx.input.iter() {
2128 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2129 for (idx, _script_pubkey) in outputs.iter() {
2130 if *idx == input.previous_output.vout {
2133 // If the expected script is a known type, check that the witness
2134 // appears to be spending the correct type (ie that the match would
2135 // actually succeed in BIP 158/159-style filters).
2136 if _script_pubkey.is_v0_p2wsh() {
2137 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2138 } else if _script_pubkey.is_v0_p2wpkh() {
2139 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2140 } else { panic!(); }
2151 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2152 // We need to consider all HTLCs which are:
2153 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2154 // transactions and we'd end up in a race, or
2155 // * are in our latest holder commitment transaction, as this is the thing we will
2156 // broadcast if we go on-chain.
2157 // Note that we consider HTLCs which were below dust threshold here - while they don't
2158 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2159 // to the source, and if we don't fail the channel we will have to ensure that the next
2160 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2161 // easier to just fail the channel as this case should be rare enough anyway.
2162 macro_rules! scan_commitment {
2163 ($htlcs: expr, $holder_tx: expr) => {
2164 for ref htlc in $htlcs {
2165 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2166 // chain with enough room to claim the HTLC without our counterparty being able to
2167 // time out the HTLC first.
2168 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2169 // concern is being able to claim the corresponding inbound HTLC (on another
2170 // channel) before it expires. In fact, we don't even really care if our
2171 // counterparty here claims such an outbound HTLC after it expired as long as we
2172 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2173 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2174 // we give ourselves a few blocks of headroom after expiration before going
2175 // on-chain for an expired HTLC.
2176 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2177 // from us until we've reached the point where we go on-chain with the
2178 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2179 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2180 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2181 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2182 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2183 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2184 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2185 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2186 // The final, above, condition is checked for statically in channelmanager
2187 // with CHECK_CLTV_EXPIRY_SANITY_2.
2188 let htlc_outbound = $holder_tx == htlc.offered;
2189 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2190 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2191 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2198 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2200 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2201 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2202 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2205 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2206 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2207 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2214 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2215 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2216 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2217 'outer_loop: for input in &tx.input {
2218 let mut payment_data = None;
2219 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2220 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2221 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2222 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2224 macro_rules! log_claim {
2225 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2226 // We found the output in question, but aren't failing it backwards
2227 // as we have no corresponding source and no valid counterparty commitment txid
2228 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2229 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2230 let outbound_htlc = $holder_tx == $htlc.offered;
2231 if ($holder_tx && revocation_sig_claim) ||
2232 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2233 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2234 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2235 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2236 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2238 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2239 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2240 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2241 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2246 macro_rules! check_htlc_valid_counterparty {
2247 ($counterparty_txid: expr, $htlc_output: expr) => {
2248 if let Some(txid) = $counterparty_txid {
2249 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2250 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2251 if let &Some(ref source) = pending_source {
2252 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2253 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2262 macro_rules! scan_commitment {
2263 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2264 for (ref htlc_output, source_option) in $htlcs {
2265 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2266 if let Some(ref source) = source_option {
2267 log_claim!($tx_info, $holder_tx, htlc_output, true);
2268 // We have a resolution of an HTLC either from one of our latest
2269 // holder commitment transactions or an unrevoked counterparty commitment
2270 // transaction. This implies we either learned a preimage, the HTLC
2271 // has timed out, or we screwed up. In any case, we should now
2272 // resolve the source HTLC with the original sender.
2273 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2274 } else if !$holder_tx {
2275 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2276 if payment_data.is_none() {
2277 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2280 if payment_data.is_none() {
2281 log_claim!($tx_info, $holder_tx, htlc_output, false);
2282 continue 'outer_loop;
2289 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2290 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2291 "our latest holder commitment tx", true);
2293 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2294 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2295 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2296 "our previous holder commitment tx", true);
2299 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2300 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2301 "counterparty commitment tx", false);
2304 // Check that scan_commitment, above, decided there is some source worth relaying an
2305 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2306 if let Some((source, payment_hash)) = payment_data {
2307 let mut payment_preimage = PaymentPreimage([0; 32]);
2308 if accepted_preimage_claim {
2309 if !self.pending_monitor_events.iter().any(
2310 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2311 payment_preimage.0.copy_from_slice(&input.witness[3]);
2312 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2314 payment_preimage: Some(payment_preimage),
2318 } else if offered_preimage_claim {
2319 if !self.pending_monitor_events.iter().any(
2320 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2321 upd.source == source
2323 payment_preimage.0.copy_from_slice(&input.witness[1]);
2324 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2326 payment_preimage: Some(payment_preimage),
2331 log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), height + ANTI_REORG_DELAY - 1);
2332 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2333 hash_map::Entry::Occupied(mut entry) => {
2334 let e = entry.get_mut();
2335 e.retain(|ref event| {
2337 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2338 return htlc_update.0 != source
2343 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2345 hash_map::Entry::Vacant(entry) => {
2346 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2354 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2355 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2356 let mut spendable_output = None;
2357 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2358 if i > ::std::u16::MAX as usize {
2359 // While it is possible that an output exists on chain which is greater than the
2360 // 2^16th output in a given transaction, this is only possible if the output is not
2361 // in a lightning transaction and was instead placed there by some third party who
2362 // wishes to give us money for no reason.
2363 // Namely, any lightning transactions which we pre-sign will never have anywhere
2364 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2365 // scripts are not longer than one byte in length and because they are inherently
2366 // non-standard due to their size.
2367 // Thus, it is completely safe to ignore such outputs, and while it may result in
2368 // us ignoring non-lightning fund to us, that is only possible if someone fills
2369 // nearly a full block with garbage just to hit this case.
2372 if outp.script_pubkey == self.destination_script {
2373 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2374 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2375 output: outp.clone(),
2378 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2379 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2380 spendable_output = Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2381 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2382 per_commitment_point: broadcasted_holder_revokable_script.1,
2383 to_self_delay: self.on_holder_tx_csv,
2384 output: outp.clone(),
2385 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2386 channel_keys_id: self.channel_keys_id,
2387 channel_value_satoshis: self.channel_value_satoshis,
2391 } else if self.counterparty_payment_script == outp.script_pubkey {
2392 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2393 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2394 output: outp.clone(),
2395 channel_keys_id: self.channel_keys_id,
2396 channel_value_satoshis: self.channel_value_satoshis,
2399 } else if outp.script_pubkey == self.shutdown_script {
2400 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2401 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2402 output: outp.clone(),
2406 if let Some(spendable_output) = spendable_output {
2407 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2408 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2409 hash_map::Entry::Occupied(mut entry) => {
2410 let e = entry.get_mut();
2411 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2413 hash_map::Entry::Vacant(entry) => {
2414 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2421 /// `Persist` defines behavior for persisting channel monitors: this could mean
2422 /// writing once to disk, and/or uploading to one or more backup services.
2424 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2425 /// to disk/backups. And, on every update, you **must** persist either the
2426 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2427 /// of situations such as revoking a transaction, then crashing before this
2428 /// revocation can be persisted, then unintentionally broadcasting a revoked
2429 /// transaction and losing money. This is a risk because previous channel states
2430 /// are toxic, so it's important that whatever channel state is persisted is
2431 /// kept up-to-date.
2432 pub trait Persist<ChannelSigner: Sign>: Send + Sync {
2433 /// Persist a new channel's data. The data can be stored any way you want, but
2434 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2435 /// it is up to you to maintain a correct mapping between the outpoint and the
2436 /// stored channel data). Note that you **must** persist every new monitor to
2437 /// disk. See the `Persist` trait documentation for more details.
2439 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2440 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2442 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2443 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2444 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2446 /// Update one channel's data. The provided `ChannelMonitor` has already
2447 /// applied the given update.
2449 /// Note that on every update, you **must** persist either the
2450 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2451 /// the `Persist` trait documentation for more details.
2453 /// If an implementer chooses to persist the updates only, they need to make
2454 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2455 /// the set of channel monitors is given to the `ChannelManager`
2456 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2457 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2458 /// persisted, then there is no need to persist individual updates.
2460 /// Note that there could be a performance tradeoff between persisting complete
2461 /// channel monitors on every update vs. persisting only updates and applying
2462 /// them in batches. The size of each monitor grows `O(number of state updates)`
2463 /// whereas updates are small and `O(1)`.
2465 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2466 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2467 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2469 /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
2470 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2471 /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
2472 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2473 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2476 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
2478 T::Target: BroadcasterInterface,
2479 F::Target: FeeEstimator,
2482 fn block_connected(&self, block: &Block, height: u32) {
2483 let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
2484 self.0.block_connected(&block.header, &txdata, height, &*self.1, &*self.2, &*self.3);
2487 fn block_disconnected(&self, header: &BlockHeader, height: u32) {
2488 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
2492 const MAX_ALLOC_SIZE: usize = 64*1024;
2494 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
2495 for (BlockHash, ChannelMonitor<Signer>) {
2496 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
2497 macro_rules! unwrap_obj {
2501 Err(_) => return Err(DecodeError::InvalidValue),
2506 let _ver: u8 = Readable::read(reader)?;
2507 let min_ver: u8 = Readable::read(reader)?;
2508 if min_ver > SERIALIZATION_VERSION {
2509 return Err(DecodeError::UnknownVersion);
2512 let latest_update_id: u64 = Readable::read(reader)?;
2513 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2515 let destination_script = Readable::read(reader)?;
2516 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2518 let revokable_address = Readable::read(reader)?;
2519 let per_commitment_point = Readable::read(reader)?;
2520 let revokable_script = Readable::read(reader)?;
2521 Some((revokable_address, per_commitment_point, revokable_script))
2524 _ => return Err(DecodeError::InvalidValue),
2526 let counterparty_payment_script = Readable::read(reader)?;
2527 let shutdown_script = Readable::read(reader)?;
2529 let channel_keys_id = Readable::read(reader)?;
2530 let holder_revocation_basepoint = Readable::read(reader)?;
2531 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2532 // barely-init'd ChannelMonitors that we can't do anything with.
2533 let outpoint = OutPoint {
2534 txid: Readable::read(reader)?,
2535 index: Readable::read(reader)?,
2537 let funding_info = (outpoint, Readable::read(reader)?);
2538 let current_counterparty_commitment_txid = Readable::read(reader)?;
2539 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2541 let counterparty_tx_cache = Readable::read(reader)?;
2542 let funding_redeemscript = Readable::read(reader)?;
2543 let channel_value_satoshis = Readable::read(reader)?;
2545 let their_cur_revocation_points = {
2546 let first_idx = <U48 as Readable>::read(reader)?.0;
2550 let first_point = Readable::read(reader)?;
2551 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2552 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2553 Some((first_idx, first_point, None))
2555 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2560 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2562 let commitment_secrets = Readable::read(reader)?;
2564 macro_rules! read_htlc_in_commitment {
2567 let offered: bool = Readable::read(reader)?;
2568 let amount_msat: u64 = Readable::read(reader)?;
2569 let cltv_expiry: u32 = Readable::read(reader)?;
2570 let payment_hash: PaymentHash = Readable::read(reader)?;
2571 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2573 HTLCOutputInCommitment {
2574 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2580 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2581 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2582 for _ in 0..counterparty_claimable_outpoints_len {
2583 let txid: Txid = Readable::read(reader)?;
2584 let htlcs_count: u64 = Readable::read(reader)?;
2585 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2586 for _ in 0..htlcs_count {
2587 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2589 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2590 return Err(DecodeError::InvalidValue);
2594 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2595 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2596 for _ in 0..counterparty_commitment_txn_on_chain_len {
2597 let txid: Txid = Readable::read(reader)?;
2598 let commitment_number = <U48 as Readable>::read(reader)?.0;
2599 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2600 return Err(DecodeError::InvalidValue);
2604 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2605 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2606 for _ in 0..counterparty_hash_commitment_number_len {
2607 let payment_hash: PaymentHash = Readable::read(reader)?;
2608 let commitment_number = <U48 as Readable>::read(reader)?.0;
2609 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2610 return Err(DecodeError::InvalidValue);
2614 macro_rules! read_holder_tx {
2617 let txid = Readable::read(reader)?;
2618 let revocation_key = Readable::read(reader)?;
2619 let a_htlc_key = Readable::read(reader)?;
2620 let b_htlc_key = Readable::read(reader)?;
2621 let delayed_payment_key = Readable::read(reader)?;
2622 let per_commitment_point = Readable::read(reader)?;
2623 let feerate_per_kw: u32 = Readable::read(reader)?;
2625 let htlcs_len: u64 = Readable::read(reader)?;
2626 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2627 for _ in 0..htlcs_len {
2628 let htlc = read_htlc_in_commitment!();
2629 let sigs = match <u8 as Readable>::read(reader)? {
2631 1 => Some(Readable::read(reader)?),
2632 _ => return Err(DecodeError::InvalidValue),
2634 htlcs.push((htlc, sigs, Readable::read(reader)?));
2639 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2646 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2649 Some(read_holder_tx!())
2651 _ => return Err(DecodeError::InvalidValue),
2653 let current_holder_commitment_tx = read_holder_tx!();
2655 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2656 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2658 let payment_preimages_len: u64 = Readable::read(reader)?;
2659 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2660 for _ in 0..payment_preimages_len {
2661 let preimage: PaymentPreimage = Readable::read(reader)?;
2662 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2663 if let Some(_) = payment_preimages.insert(hash, preimage) {
2664 return Err(DecodeError::InvalidValue);
2668 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2669 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2670 for _ in 0..pending_monitor_events_len {
2671 let ev = match <u8 as Readable>::read(reader)? {
2672 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2673 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2674 _ => return Err(DecodeError::InvalidValue)
2676 pending_monitor_events.push(ev);
2679 let pending_events_len: u64 = Readable::read(reader)?;
2680 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2681 for _ in 0..pending_events_len {
2682 if let Some(event) = MaybeReadable::read(reader)? {
2683 pending_events.push(event);
2687 let last_block_hash: BlockHash = Readable::read(reader)?;
2689 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2690 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2691 for _ in 0..waiting_threshold_conf_len {
2692 let height_target = Readable::read(reader)?;
2693 let events_len: u64 = Readable::read(reader)?;
2694 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2695 for _ in 0..events_len {
2696 let ev = match <u8 as Readable>::read(reader)? {
2698 let htlc_source = Readable::read(reader)?;
2699 let hash = Readable::read(reader)?;
2700 OnchainEvent::HTLCUpdate {
2701 htlc_update: (htlc_source, hash)
2705 let descriptor = Readable::read(reader)?;
2706 OnchainEvent::MaturingOutput {
2710 _ => return Err(DecodeError::InvalidValue),
2714 onchain_events_waiting_threshold_conf.insert(height_target, events);
2717 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2718 let mut outputs_to_watch = HashMap::with_capacity(cmp::min(outputs_to_watch_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<Txid>() + mem::size_of::<u32>() + mem::size_of::<Vec<Script>>())));
2719 for _ in 0..outputs_to_watch_len {
2720 let txid = Readable::read(reader)?;
2721 let outputs_len: u64 = Readable::read(reader)?;
2722 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2723 for _ in 0..outputs_len {
2724 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2726 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2727 return Err(DecodeError::InvalidValue);
2730 let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
2732 let lockdown_from_offchain = Readable::read(reader)?;
2733 let holder_tx_signed = Readable::read(reader)?;
2735 let mut secp_ctx = Secp256k1::new();
2736 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
2738 Ok((last_block_hash.clone(), ChannelMonitor {
2739 inner: Mutex::new(ChannelMonitorImpl {
2741 commitment_transaction_number_obscure_factor,
2744 broadcasted_holder_revokable_script,
2745 counterparty_payment_script,
2749 holder_revocation_basepoint,
2751 current_counterparty_commitment_txid,
2752 prev_counterparty_commitment_txid,
2754 counterparty_tx_cache,
2755 funding_redeemscript,
2756 channel_value_satoshis,
2757 their_cur_revocation_points,
2762 counterparty_claimable_outpoints,
2763 counterparty_commitment_txn_on_chain,
2764 counterparty_hash_commitment_number,
2766 prev_holder_signed_commitment_tx,
2767 current_holder_commitment_tx,
2768 current_counterparty_commitment_number,
2769 current_holder_commitment_number,
2772 pending_monitor_events,
2775 onchain_events_waiting_threshold_conf,
2780 lockdown_from_offchain,
2792 use bitcoin::blockdata::script::{Script, Builder};
2793 use bitcoin::blockdata::opcodes;
2794 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2795 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2796 use bitcoin::util::bip143;
2797 use bitcoin::hashes::Hash;
2798 use bitcoin::hashes::sha256::Hash as Sha256;
2799 use bitcoin::hashes::hex::FromHex;
2800 use bitcoin::hash_types::Txid;
2802 use chain::channelmonitor::ChannelMonitor;
2803 use chain::transaction::OutPoint;
2804 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2805 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2807 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
2808 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2809 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2810 use bitcoin::secp256k1::Secp256k1;
2811 use std::sync::{Arc, Mutex};
2812 use chain::keysinterface::InMemorySigner;
2815 fn test_prune_preimages() {
2816 let secp_ctx = Secp256k1::new();
2817 let logger = Arc::new(TestLogger::new());
2818 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
2819 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
2821 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2822 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2824 let mut preimages = Vec::new();
2827 let preimage = PaymentPreimage([i; 32]);
2828 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2829 preimages.push((preimage, hash));
2833 macro_rules! preimages_slice_to_htlc_outputs {
2834 ($preimages_slice: expr) => {
2836 let mut res = Vec::new();
2837 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2838 res.push((HTLCOutputInCommitment {
2842 payment_hash: preimage.1.clone(),
2843 transaction_output_index: Some(idx as u32),
2850 macro_rules! preimages_to_holder_htlcs {
2851 ($preimages_slice: expr) => {
2853 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2854 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2860 macro_rules! test_preimages_exist {
2861 ($preimages_slice: expr, $monitor: expr) => {
2862 for preimage in $preimages_slice {
2863 assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
2868 let keys = InMemorySigner::new(
2870 SecretKey::from_slice(&[41; 32]).unwrap(),
2871 SecretKey::from_slice(&[41; 32]).unwrap(),
2872 SecretKey::from_slice(&[41; 32]).unwrap(),
2873 SecretKey::from_slice(&[41; 32]).unwrap(),
2874 SecretKey::from_slice(&[41; 32]).unwrap(),
2880 let counterparty_pubkeys = ChannelPublicKeys {
2881 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2882 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2883 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
2884 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
2885 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
2887 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
2888 let channel_parameters = ChannelTransactionParameters {
2889 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
2890 holder_selected_contest_delay: 66,
2891 is_outbound_from_holder: true,
2892 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
2893 pubkeys: counterparty_pubkeys,
2894 selected_contest_delay: 67,
2896 funding_outpoint: Some(funding_outpoint),
2898 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2900 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
2901 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2902 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2903 &channel_parameters,
2904 Script::new(), 46, 0,
2905 HolderCommitmentTransaction::dummy());
2907 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2908 let dummy_txid = dummy_tx.txid();
2909 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2910 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2911 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2912 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2913 for &(ref preimage, ref hash) in preimages.iter() {
2914 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2917 // Now provide a secret, pruning preimages 10-15
2918 let mut secret = [0; 32];
2919 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2920 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2921 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
2922 test_preimages_exist!(&preimages[0..10], monitor);
2923 test_preimages_exist!(&preimages[15..20], monitor);
2925 // Now provide a further secret, pruning preimages 15-17
2926 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2927 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2928 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
2929 test_preimages_exist!(&preimages[0..10], monitor);
2930 test_preimages_exist!(&preimages[17..20], monitor);
2932 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2933 // previous commitment tx's preimages too
2934 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2935 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2936 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2937 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
2938 test_preimages_exist!(&preimages[0..10], monitor);
2939 test_preimages_exist!(&preimages[18..20], monitor);
2941 // But if we do it again, we'll prune 5-10
2942 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2943 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2944 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2945 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
2946 test_preimages_exist!(&preimages[0..5], monitor);
2950 fn test_claim_txn_weight_computation() {
2951 // We test Claim txn weight, knowing that we want expected weigth and
2952 // not actual case to avoid sigs and time-lock delays hell variances.
2954 let secp_ctx = Secp256k1::new();
2955 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2956 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2957 let mut sum_actual_sigs = 0;
2959 macro_rules! sign_input {
2960 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2961 let htlc = HTLCOutputInCommitment {
2962 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2964 cltv_expiry: 2 << 16,
2965 payment_hash: PaymentHash([1; 32]),
2966 transaction_output_index: Some($idx as u32),
2968 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2969 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2970 let sig = secp_ctx.sign(&sighash, &privkey);
2971 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2972 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2973 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2974 if *$input_type == InputDescriptors::RevokedOutput {
2975 $sighash_parts.access_witness($idx).push(vec!(1));
2976 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2977 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2978 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2979 $sighash_parts.access_witness($idx).push(vec![0]);
2981 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2983 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2984 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2985 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2986 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2990 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2991 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2993 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2994 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2996 claim_tx.input.push(TxIn {
2997 previous_output: BitcoinOutPoint {
3001 script_sig: Script::new(),
3002 sequence: 0xfffffffd,
3003 witness: Vec::new(),
3006 claim_tx.output.push(TxOut {
3007 script_pubkey: script_pubkey.clone(),
3010 let base_weight = claim_tx.get_weight();
3011 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
3013 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3014 for (idx, inp) in inputs_des.iter().enumerate() {
3015 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3018 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
3020 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3021 claim_tx.input.clear();
3022 sum_actual_sigs = 0;
3024 claim_tx.input.push(TxIn {
3025 previous_output: BitcoinOutPoint {
3029 script_sig: Script::new(),
3030 sequence: 0xfffffffd,
3031 witness: Vec::new(),
3034 let base_weight = claim_tx.get_weight();
3035 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
3037 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3038 for (idx, inp) in inputs_des.iter().enumerate() {
3039 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3042 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
3044 // Justice tx with 1 revoked HTLC-Success tx output
3045 claim_tx.input.clear();
3046 sum_actual_sigs = 0;
3047 claim_tx.input.push(TxIn {
3048 previous_output: BitcoinOutPoint {
3052 script_sig: Script::new(),
3053 sequence: 0xfffffffd,
3054 witness: Vec::new(),
3056 let base_weight = claim_tx.get_weight();
3057 let inputs_des = vec![InputDescriptors::RevokedOutput];
3059 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3060 for (idx, inp) in inputs_des.iter().enumerate() {
3061 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3064 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
3067 // Further testing is done in the ChannelManager integration tests.