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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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,
984 last_block_hash: BlockHash) -> ChannelMonitor<Signer> {
986 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
987 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
988 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
989 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
990 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
992 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
993 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
994 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
995 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
997 let channel_keys_id = keys.channel_keys_id();
998 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1000 // block for Rust 1.34 compat
1001 let (holder_commitment_tx, current_holder_commitment_number) = {
1002 let trusted_tx = initial_holder_commitment_tx.trust();
1003 let txid = trusted_tx.txid();
1005 let tx_keys = trusted_tx.keys();
1006 let holder_commitment_tx = HolderSignedTx {
1008 revocation_key: tx_keys.revocation_key,
1009 a_htlc_key: tx_keys.broadcaster_htlc_key,
1010 b_htlc_key: tx_keys.countersignatory_htlc_key,
1011 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1012 per_commitment_point: tx_keys.per_commitment_point,
1013 feerate_per_kw: trusted_tx.feerate_per_kw(),
1014 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1016 (holder_commitment_tx, trusted_tx.commitment_number())
1019 let onchain_tx_handler =
1020 OnchainTxHandler::new(destination_script.clone(), keys,
1021 channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
1023 let mut outputs_to_watch = HashMap::new();
1024 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1027 inner: Mutex::new(ChannelMonitorImpl {
1028 latest_update_id: 0,
1029 commitment_transaction_number_obscure_factor,
1031 destination_script: destination_script.clone(),
1032 broadcasted_holder_revokable_script: None,
1033 counterparty_payment_script,
1037 holder_revocation_basepoint,
1039 current_counterparty_commitment_txid: None,
1040 prev_counterparty_commitment_txid: None,
1042 counterparty_tx_cache,
1043 funding_redeemscript,
1044 channel_value_satoshis,
1045 their_cur_revocation_points: None,
1047 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1049 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1050 counterparty_claimable_outpoints: HashMap::new(),
1051 counterparty_commitment_txn_on_chain: HashMap::new(),
1052 counterparty_hash_commitment_number: HashMap::new(),
1054 prev_holder_signed_commitment_tx: None,
1055 current_holder_commitment_tx: holder_commitment_tx,
1056 current_counterparty_commitment_number: 1 << 48,
1057 current_holder_commitment_number,
1059 payment_preimages: HashMap::new(),
1060 pending_monitor_events: Vec::new(),
1061 pending_events: Vec::new(),
1063 onchain_events_waiting_threshold_conf: HashMap::new(),
1068 lockdown_from_offchain: false,
1069 holder_tx_signed: false,
1078 fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1079 self.inner.lock().unwrap().provide_secret(idx, secret)
1082 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1083 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1084 /// possibly future revocation/preimage information) to claim outputs where possible.
1085 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1086 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1089 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1090 commitment_number: u64,
1091 their_revocation_point: PublicKey,
1093 ) where L::Target: Logger {
1094 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1095 txid, htlc_outputs, commitment_number, their_revocation_point, logger)
1099 fn provide_latest_holder_commitment_tx(
1101 holder_commitment_tx: HolderCommitmentTransaction,
1102 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1103 ) -> Result<(), MonitorUpdateError> {
1104 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
1105 holder_commitment_tx, htlc_outputs)
1109 pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1111 payment_hash: &PaymentHash,
1112 payment_preimage: &PaymentPreimage,
1117 B::Target: BroadcasterInterface,
1118 F::Target: FeeEstimator,
1121 self.inner.lock().unwrap().provide_payment_preimage(
1122 payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1125 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1130 B::Target: BroadcasterInterface,
1133 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
1136 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1139 /// panics if the given update is not the next update by update_id.
1140 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1142 updates: &ChannelMonitorUpdate,
1146 ) -> Result<(), MonitorUpdateError>
1148 B::Target: BroadcasterInterface,
1149 F::Target: FeeEstimator,
1152 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1155 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1157 pub fn get_latest_update_id(&self) -> u64 {
1158 self.inner.lock().unwrap().get_latest_update_id()
1161 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1162 pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1163 self.inner.lock().unwrap().get_funding_txo().clone()
1166 /// Gets a list of txids, with their output scripts (in the order they appear in the
1167 /// transaction), which we must learn about spends of via block_connected().
1169 /// (C-not exported) because we have no HashMap bindings
1170 pub fn get_outputs_to_watch(&self) -> HashMap<Txid, Vec<(u32, Script)>> {
1171 self.inner.lock().unwrap().get_outputs_to_watch().clone()
1174 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1175 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1177 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
1178 pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1179 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1182 /// Gets the list of pending events which were generated by previous actions, clearing the list
1185 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1186 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1187 /// no internal locking in ChannelMonitors.
1188 pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1189 self.inner.lock().unwrap().get_and_clear_pending_events()
1192 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1193 self.inner.lock().unwrap().get_min_seen_secret()
1196 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1197 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1200 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1201 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1204 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1205 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1206 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1207 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1208 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1209 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1210 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1211 /// out-of-band the other node operator to coordinate with him if option is available to you.
1212 /// In any-case, choice is up to the user.
1213 pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1214 where L::Target: Logger {
1215 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1218 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1219 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1220 /// revoked commitment transaction.
1221 #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1222 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1223 where L::Target: Logger {
1224 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1227 /// Processes transactions in a newly connected block, which may result in any of the following:
1228 /// - update the monitor's state against resolved HTLCs
1229 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1230 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1231 /// - detect settled outputs for later spending
1232 /// - schedule and bump any in-flight claims
1234 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1235 /// [`get_outputs_to_watch`].
1237 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1238 pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1240 header: &BlockHeader,
1241 txdata: &TransactionData,
1246 ) -> Vec<(Txid, Vec<(u32, TxOut)>)>
1248 B::Target: BroadcasterInterface,
1249 F::Target: FeeEstimator,
1252 self.inner.lock().unwrap().block_connected(
1253 header, txdata, height, broadcaster, fee_estimator, logger)
1256 /// Determines if the disconnected block contained any transactions of interest and updates
1258 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1260 header: &BlockHeader,
1266 B::Target: BroadcasterInterface,
1267 F::Target: FeeEstimator,
1270 self.inner.lock().unwrap().block_disconnected(
1271 header, height, broadcaster, fee_estimator, logger)
1275 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1276 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1277 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1278 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1279 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1280 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1281 return Err(MonitorUpdateError("Previous secret did not match new one"));
1284 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1285 // events for now-revoked/fulfilled HTLCs.
1286 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1287 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1292 if !self.payment_preimages.is_empty() {
1293 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1294 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1295 let min_idx = self.get_min_seen_secret();
1296 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1298 self.payment_preimages.retain(|&k, _| {
1299 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1300 if k == htlc.payment_hash {
1304 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1305 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1306 if k == htlc.payment_hash {
1311 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1318 counterparty_hash_commitment_number.remove(&k);
1327 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 {
1328 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1329 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1330 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1332 for &(ref htlc, _) in &htlc_outputs {
1333 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1336 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1337 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1338 self.current_counterparty_commitment_txid = Some(txid);
1339 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1340 self.current_counterparty_commitment_number = commitment_number;
1341 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1342 match self.their_cur_revocation_points {
1343 Some(old_points) => {
1344 if old_points.0 == commitment_number + 1 {
1345 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1346 } else if old_points.0 == commitment_number + 2 {
1347 if let Some(old_second_point) = old_points.2 {
1348 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1350 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1353 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1357 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1360 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1361 for htlc in htlc_outputs {
1362 if htlc.0.transaction_output_index.is_some() {
1366 self.counterparty_tx_cache.per_htlc.insert(txid, htlcs);
1369 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1370 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1371 /// is important that any clones of this channel monitor (including remote clones) by kept
1372 /// up-to-date as our holder commitment transaction is updated.
1373 /// Panics if set_on_holder_tx_csv has never been called.
1374 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1375 // block for Rust 1.34 compat
1376 let mut new_holder_commitment_tx = {
1377 let trusted_tx = holder_commitment_tx.trust();
1378 let txid = trusted_tx.txid();
1379 let tx_keys = trusted_tx.keys();
1380 self.current_holder_commitment_number = trusted_tx.commitment_number();
1383 revocation_key: tx_keys.revocation_key,
1384 a_htlc_key: tx_keys.broadcaster_htlc_key,
1385 b_htlc_key: tx_keys.countersignatory_htlc_key,
1386 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1387 per_commitment_point: tx_keys.per_commitment_point,
1388 feerate_per_kw: trusted_tx.feerate_per_kw(),
1392 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1393 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1394 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1395 if self.holder_tx_signed {
1396 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1401 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1402 /// commitment_tx_infos which contain the payment hash have been revoked.
1403 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)
1404 where B::Target: BroadcasterInterface,
1405 F::Target: FeeEstimator,
1408 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1410 // If the channel is force closed, try to claim the output from this preimage.
1411 // First check if a counterparty commitment transaction has been broadcasted:
1412 macro_rules! claim_htlcs {
1413 ($commitment_number: expr, $txid: expr) => {
1414 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1415 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, None, broadcaster, fee_estimator, logger);
1418 if let Some(txid) = self.current_counterparty_commitment_txid {
1419 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1420 claim_htlcs!(*commitment_number, txid);
1424 if let Some(txid) = self.prev_counterparty_commitment_txid {
1425 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1426 claim_htlcs!(*commitment_number, txid);
1431 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1432 // claiming the HTLC output from each of the holder commitment transactions.
1433 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1434 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1435 // holder commitment transactions.
1436 if self.broadcasted_holder_revokable_script.is_some() {
1437 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1438 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1439 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1440 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx);
1441 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1446 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1447 where B::Target: BroadcasterInterface,
1450 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1451 broadcaster.broadcast_transaction(tx);
1453 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1456 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1457 where B::Target: BroadcasterInterface,
1458 F::Target: FeeEstimator,
1461 // ChannelMonitor updates may be applied after force close if we receive a
1462 // preimage for a broadcasted commitment transaction HTLC output that we'd
1463 // like to claim on-chain. If this is the case, we no longer have guaranteed
1464 // access to the monitor's update ID, so we use a sentinel value instead.
1465 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1466 match updates.updates[0] {
1467 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1468 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1470 assert_eq!(updates.updates.len(), 1);
1471 } else if self.latest_update_id + 1 != updates.update_id {
1472 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1474 for update in updates.updates.iter() {
1476 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1477 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1478 if self.lockdown_from_offchain { panic!(); }
1479 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1481 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1482 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1483 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1485 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1486 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1487 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1489 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1490 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1491 self.provide_secret(*idx, *secret)?
1493 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1494 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1495 self.lockdown_from_offchain = true;
1496 if *should_broadcast {
1497 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1499 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");
1504 self.latest_update_id = updates.update_id;
1508 pub fn get_latest_update_id(&self) -> u64 {
1509 self.latest_update_id
1512 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1516 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1517 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1518 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1519 // its trivial to do, double-check that here.
1520 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1521 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1523 &self.outputs_to_watch
1526 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1527 let mut ret = Vec::new();
1528 mem::swap(&mut ret, &mut self.pending_monitor_events);
1532 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1533 let mut ret = Vec::new();
1534 mem::swap(&mut ret, &mut self.pending_events);
1538 /// Can only fail if idx is < get_min_seen_secret
1539 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1540 self.commitment_secrets.get_secret(idx)
1543 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1544 self.commitment_secrets.get_min_seen_secret()
1547 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1548 self.current_counterparty_commitment_number
1551 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1552 self.current_holder_commitment_number
1555 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1556 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1557 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1558 /// HTLC-Success/HTLC-Timeout transactions.
1559 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1560 /// revoked counterparty commitment tx
1561 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 {
1562 // Most secp and related errors trying to create keys means we have no hope of constructing
1563 // a spend transaction...so we return no transactions to broadcast
1564 let mut claimable_outpoints = Vec::new();
1565 let mut watch_outputs = Vec::new();
1567 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1568 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1570 macro_rules! ignore_error {
1571 ( $thing : expr ) => {
1574 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1579 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);
1580 if commitment_number >= self.get_min_seen_secret() {
1581 let secret = self.get_secret(commitment_number).unwrap();
1582 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1583 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1584 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
1585 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));
1587 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1588 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1590 // First, process non-htlc outputs (to_holder & to_counterparty)
1591 for (idx, outp) in tx.output.iter().enumerate() {
1592 if outp.script_pubkey == revokeable_p2wsh {
1593 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};
1594 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});
1598 // Then, try to find revoked htlc outputs
1599 if let Some(ref per_commitment_data) = per_commitment_option {
1600 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1601 if let Some(transaction_output_index) = htlc.transaction_output_index {
1602 if transaction_output_index as usize >= tx.output.len() ||
1603 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1604 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1606 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};
1607 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1612 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1613 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1614 // We're definitely a counterparty commitment transaction!
1615 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1616 for (idx, outp) in tx.output.iter().enumerate() {
1617 watch_outputs.push((idx as u32, outp.clone()));
1619 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1621 macro_rules! check_htlc_fails {
1622 ($txid: expr, $commitment_tx: expr) => {
1623 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1624 for &(ref htlc, ref source_option) in outpoints.iter() {
1625 if let &Some(ref source) = source_option {
1626 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1627 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1628 hash_map::Entry::Occupied(mut entry) => {
1629 let e = entry.get_mut();
1630 e.retain(|ref event| {
1632 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1633 return htlc_update.0 != **source
1638 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1640 hash_map::Entry::Vacant(entry) => {
1641 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1649 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1650 check_htlc_fails!(txid, "current");
1652 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1653 check_htlc_fails!(txid, "counterparty");
1655 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1657 } else if let Some(per_commitment_data) = per_commitment_option {
1658 // While this isn't useful yet, there is a potential race where if a counterparty
1659 // revokes a state at the same time as the commitment transaction for that state is
1660 // confirmed, and the watchtower receives the block before the user, the user could
1661 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1662 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1663 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1665 for (idx, outp) in tx.output.iter().enumerate() {
1666 watch_outputs.push((idx as u32, outp.clone()));
1668 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1670 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1672 macro_rules! check_htlc_fails {
1673 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1674 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1675 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1676 if let &Some(ref source) = source_option {
1677 // Check if the HTLC is present in the commitment transaction that was
1678 // broadcast, but not if it was below the dust limit, which we should
1679 // fail backwards immediately as there is no way for us to learn the
1680 // payment_preimage.
1681 // Note that if the dust limit were allowed to change between
1682 // commitment transactions we'd want to be check whether *any*
1683 // broadcastable commitment transaction has the HTLC in it, but it
1684 // cannot currently change after channel initialization, so we don't
1686 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1687 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1691 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);
1692 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1693 hash_map::Entry::Occupied(mut entry) => {
1694 let e = entry.get_mut();
1695 e.retain(|ref event| {
1697 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1698 return htlc_update.0 != **source
1703 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1705 hash_map::Entry::Vacant(entry) => {
1706 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1714 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1715 check_htlc_fails!(txid, "current", 'current_loop);
1717 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1718 check_htlc_fails!(txid, "previous", 'prev_loop);
1721 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
1722 for req in htlc_claim_reqs {
1723 claimable_outpoints.push(req);
1727 (claimable_outpoints, (commitment_txid, watch_outputs))
1730 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<ClaimRequest> {
1731 let mut claims = Vec::new();
1732 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
1733 if let Some(revocation_points) = self.their_cur_revocation_points {
1734 let revocation_point_option =
1735 // If the counterparty commitment tx is the latest valid state, use their latest
1736 // per-commitment point
1737 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1738 else if let Some(point) = revocation_points.2.as_ref() {
1739 // If counterparty commitment tx is the state previous to the latest valid state, use
1740 // their previous per-commitment point (non-atomicity of revocation means it's valid for
1741 // them to temporarily have two valid commitment txns from our viewpoint)
1742 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1744 if let Some(revocation_point) = revocation_point_option {
1745 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
1746 if let Some(transaction_output_index) = htlc.transaction_output_index {
1747 if let Some(transaction) = tx {
1748 if transaction_output_index as usize >= transaction.output.len() ||
1749 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1750 return claims; // Corrupted per_commitment_data, fuck this user
1755 if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) {
1759 let aggregable = if !htlc.offered { false } else { true };
1760 if preimage.is_some() || !htlc.offered {
1761 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() };
1762 claims.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1772 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1773 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 {
1774 let htlc_txid = tx.txid();
1775 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1776 return (Vec::new(), None)
1779 macro_rules! ignore_error {
1780 ( $thing : expr ) => {
1783 Err(_) => return (Vec::new(), None)
1788 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1789 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1790 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1792 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1793 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 };
1794 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 });
1795 let outputs = vec![(0, tx.output[0].clone())];
1796 (claimable_outpoints, Some((htlc_txid, outputs)))
1799 // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can
1800 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1801 // script so we can detect whether a holder transaction has been seen on-chain.
1802 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Option<(Script, PublicKey, PublicKey)>) {
1803 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1805 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1806 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1808 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1809 if let Some(transaction_output_index) = htlc.transaction_output_index {
1810 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1811 witness_data: InputMaterial::HolderHTLC {
1812 preimage: if !htlc.offered {
1813 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1814 Some(preimage.clone())
1816 // We can't build an HTLC-Success transaction without the preimage
1820 amount: htlc.amount_msat,
1825 (claim_requests, broadcasted_holder_revokable_script)
1828 // Returns holder HTLC outputs to watch and react to in case of spending.
1829 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1830 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1831 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1832 if let Some(transaction_output_index) = htlc.transaction_output_index {
1833 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1839 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1840 /// revoked using data in holder_claimable_outpoints.
1841 /// Should not be used if check_spend_revoked_transaction succeeds.
1842 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 {
1843 let commitment_txid = tx.txid();
1844 let mut claim_requests = Vec::new();
1845 let mut watch_outputs = Vec::new();
1847 macro_rules! wait_threshold_conf {
1848 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1849 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1850 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1851 hash_map::Entry::Occupied(mut entry) => {
1852 let e = entry.get_mut();
1853 e.retain(|ref event| {
1855 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1856 return htlc_update.0 != $source
1861 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1863 hash_map::Entry::Vacant(entry) => {
1864 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1870 macro_rules! append_onchain_update {
1871 ($updates: expr, $to_watch: expr) => {
1872 claim_requests = $updates.0;
1873 self.broadcasted_holder_revokable_script = $updates.1;
1874 watch_outputs.append(&mut $to_watch);
1878 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1879 let mut is_holder_tx = false;
1881 if self.current_holder_commitment_tx.txid == commitment_txid {
1882 is_holder_tx = true;
1883 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1884 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1885 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1886 append_onchain_update!(res, to_watch);
1887 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1888 if holder_tx.txid == commitment_txid {
1889 is_holder_tx = true;
1890 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1891 let res = self.get_broadcasted_holder_claims(holder_tx);
1892 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1893 append_onchain_update!(res, to_watch);
1897 macro_rules! fail_dust_htlcs_after_threshold_conf {
1898 ($holder_tx: expr) => {
1899 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1900 if htlc.transaction_output_index.is_none() {
1901 if let &Some(ref source) = source {
1902 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1910 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1911 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1912 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1916 (claim_requests, (commitment_txid, watch_outputs))
1919 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1920 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1921 self.holder_tx_signed = true;
1922 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
1923 let txid = commitment_tx.txid();
1924 let mut res = vec![commitment_tx];
1925 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1926 if let Some(vout) = htlc.0.transaction_output_index {
1927 let preimage = if !htlc.0.offered {
1928 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1929 // We can't build an HTLC-Success transaction without the preimage
1933 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1934 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1939 // 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.
1940 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1944 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1945 fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1946 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1947 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
1948 let txid = commitment_tx.txid();
1949 let mut res = vec![commitment_tx];
1950 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1951 if let Some(vout) = htlc.0.transaction_output_index {
1952 let preimage = if !htlc.0.offered {
1953 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1954 // We can't build an HTLC-Success transaction without the preimage
1958 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1959 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1967 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)>)>
1968 where B::Target: BroadcasterInterface,
1969 F::Target: FeeEstimator,
1972 let txn_matched = self.filter_block(txdata);
1973 for tx in &txn_matched {
1974 let mut output_val = 0;
1975 for out in tx.output.iter() {
1976 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1977 output_val += out.value;
1978 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1982 let block_hash = header.block_hash();
1983 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1985 let mut watch_outputs = Vec::new();
1986 let mut claimable_outpoints = Vec::new();
1987 for tx in &txn_matched {
1988 if tx.input.len() == 1 {
1989 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1990 // commitment transactions and HTLC transactions will all only ever have one input,
1991 // which is an easy way to filter out any potential non-matching txn for lazy
1993 let prevout = &tx.input[0].previous_output;
1994 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1995 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1996 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1997 if !new_outputs.1.is_empty() {
1998 watch_outputs.push(new_outputs);
2000 if new_outpoints.is_empty() {
2001 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
2002 if !new_outputs.1.is_empty() {
2003 watch_outputs.push(new_outputs);
2005 claimable_outpoints.append(&mut new_outpoints);
2007 claimable_outpoints.append(&mut new_outpoints);
2010 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2011 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2012 claimable_outpoints.append(&mut new_outpoints);
2013 if let Some(new_outputs) = new_outputs_option {
2014 watch_outputs.push(new_outputs);
2019 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2020 // can also be resolved in a few other ways which can have more than one output. Thus,
2021 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2022 self.is_resolving_htlc_output(&tx, height, &logger);
2024 self.is_paying_spendable_output(&tx, height, &logger);
2026 let should_broadcast = self.would_broadcast_at_height(height, &logger);
2027 if should_broadcast {
2028 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() }});
2030 if should_broadcast {
2031 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
2032 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2033 self.holder_tx_signed = true;
2034 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
2035 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2036 if !new_outputs.is_empty() {
2037 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2039 claimable_outpoints.append(&mut new_outpoints);
2041 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
2044 OnchainEvent::HTLCUpdate { htlc_update } => {
2045 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
2046 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2047 payment_hash: htlc_update.1,
2048 payment_preimage: None,
2049 source: htlc_update.0,
2052 OnchainEvent::MaturingOutput { descriptor } => {
2053 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2054 self.pending_events.push(Event::SpendableOutputs {
2055 outputs: vec![descriptor]
2062 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
2063 self.last_block_hash = block_hash;
2065 // Determine new outputs to watch by comparing against previously known outputs to watch,
2066 // updating the latter in the process.
2067 watch_outputs.retain(|&(ref txid, ref txouts)| {
2068 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2069 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2073 // If we see a transaction for which we registered outputs previously,
2074 // make sure the registered scriptpubkey at the expected index match
2075 // the actual transaction output one. We failed this case before #653.
2076 for tx in &txn_matched {
2077 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2078 for idx_and_script in outputs.iter() {
2079 assert!((idx_and_script.0 as usize) < tx.output.len());
2080 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2088 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2089 where B::Target: BroadcasterInterface,
2090 F::Target: FeeEstimator,
2093 let block_hash = header.block_hash();
2094 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
2096 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
2098 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2099 //- maturing spendable output has transaction paying us has been disconnected
2102 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2104 self.last_block_hash = block_hash;
2107 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2108 /// transactions thereof.
2109 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2110 let mut matched_txn = HashSet::new();
2111 txdata.iter().filter(|&&(_, tx)| {
2112 let mut matches = self.spends_watched_output(tx);
2113 for input in tx.input.iter() {
2114 if matches { break; }
2115 if matched_txn.contains(&input.previous_output.txid) {
2120 matched_txn.insert(tx.txid());
2123 }).map(|(_, tx)| *tx).collect()
2126 /// Checks if a given transaction spends any watched outputs.
2127 fn spends_watched_output(&self, tx: &Transaction) -> bool {
2128 for input in tx.input.iter() {
2129 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2130 for (idx, _script_pubkey) in outputs.iter() {
2131 if *idx == input.previous_output.vout {
2134 // If the expected script is a known type, check that the witness
2135 // appears to be spending the correct type (ie that the match would
2136 // actually succeed in BIP 158/159-style filters).
2137 if _script_pubkey.is_v0_p2wsh() {
2138 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2139 } else if _script_pubkey.is_v0_p2wpkh() {
2140 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2141 } else { panic!(); }
2152 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
2153 // We need to consider all HTLCs which are:
2154 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2155 // transactions and we'd end up in a race, or
2156 // * are in our latest holder commitment transaction, as this is the thing we will
2157 // broadcast if we go on-chain.
2158 // Note that we consider HTLCs which were below dust threshold here - while they don't
2159 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2160 // to the source, and if we don't fail the channel we will have to ensure that the next
2161 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2162 // easier to just fail the channel as this case should be rare enough anyway.
2163 macro_rules! scan_commitment {
2164 ($htlcs: expr, $holder_tx: expr) => {
2165 for ref htlc in $htlcs {
2166 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2167 // chain with enough room to claim the HTLC without our counterparty being able to
2168 // time out the HTLC first.
2169 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2170 // concern is being able to claim the corresponding inbound HTLC (on another
2171 // channel) before it expires. In fact, we don't even really care if our
2172 // counterparty here claims such an outbound HTLC after it expired as long as we
2173 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2174 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2175 // we give ourselves a few blocks of headroom after expiration before going
2176 // on-chain for an expired HTLC.
2177 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2178 // from us until we've reached the point where we go on-chain with the
2179 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2180 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2181 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2182 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2183 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2184 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2185 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2186 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2187 // The final, above, condition is checked for statically in channelmanager
2188 // with CHECK_CLTV_EXPIRY_SANITY_2.
2189 let htlc_outbound = $holder_tx == htlc.offered;
2190 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2191 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2192 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2199 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2201 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2202 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2203 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2206 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2207 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2208 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2215 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2216 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2217 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2218 'outer_loop: for input in &tx.input {
2219 let mut payment_data = None;
2220 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2221 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2222 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2223 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2225 macro_rules! log_claim {
2226 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2227 // We found the output in question, but aren't failing it backwards
2228 // as we have no corresponding source and no valid counterparty commitment txid
2229 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2230 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2231 let outbound_htlc = $holder_tx == $htlc.offered;
2232 if ($holder_tx && revocation_sig_claim) ||
2233 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2234 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2235 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2236 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2237 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2239 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2240 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2241 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2242 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2247 macro_rules! check_htlc_valid_counterparty {
2248 ($counterparty_txid: expr, $htlc_output: expr) => {
2249 if let Some(txid) = $counterparty_txid {
2250 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2251 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2252 if let &Some(ref source) = pending_source {
2253 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2254 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2263 macro_rules! scan_commitment {
2264 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2265 for (ref htlc_output, source_option) in $htlcs {
2266 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2267 if let Some(ref source) = source_option {
2268 log_claim!($tx_info, $holder_tx, htlc_output, true);
2269 // We have a resolution of an HTLC either from one of our latest
2270 // holder commitment transactions or an unrevoked counterparty commitment
2271 // transaction. This implies we either learned a preimage, the HTLC
2272 // has timed out, or we screwed up. In any case, we should now
2273 // resolve the source HTLC with the original sender.
2274 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2275 } else if !$holder_tx {
2276 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2277 if payment_data.is_none() {
2278 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2281 if payment_data.is_none() {
2282 log_claim!($tx_info, $holder_tx, htlc_output, false);
2283 continue 'outer_loop;
2290 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2291 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2292 "our latest holder commitment tx", true);
2294 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2295 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2296 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2297 "our previous holder commitment tx", true);
2300 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2301 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2302 "counterparty commitment tx", false);
2305 // Check that scan_commitment, above, decided there is some source worth relaying an
2306 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2307 if let Some((source, payment_hash)) = payment_data {
2308 let mut payment_preimage = PaymentPreimage([0; 32]);
2309 if accepted_preimage_claim {
2310 if !self.pending_monitor_events.iter().any(
2311 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2312 payment_preimage.0.copy_from_slice(&input.witness[3]);
2313 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2315 payment_preimage: Some(payment_preimage),
2319 } else if offered_preimage_claim {
2320 if !self.pending_monitor_events.iter().any(
2321 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2322 upd.source == source
2324 payment_preimage.0.copy_from_slice(&input.witness[1]);
2325 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2327 payment_preimage: Some(payment_preimage),
2332 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);
2333 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2334 hash_map::Entry::Occupied(mut entry) => {
2335 let e = entry.get_mut();
2336 e.retain(|ref event| {
2338 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2339 return htlc_update.0 != source
2344 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2346 hash_map::Entry::Vacant(entry) => {
2347 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2355 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2356 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2357 let mut spendable_output = None;
2358 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2359 if i > ::std::u16::MAX as usize {
2360 // While it is possible that an output exists on chain which is greater than the
2361 // 2^16th output in a given transaction, this is only possible if the output is not
2362 // in a lightning transaction and was instead placed there by some third party who
2363 // wishes to give us money for no reason.
2364 // Namely, any lightning transactions which we pre-sign will never have anywhere
2365 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2366 // scripts are not longer than one byte in length and because they are inherently
2367 // non-standard due to their size.
2368 // Thus, it is completely safe to ignore such outputs, and while it may result in
2369 // us ignoring non-lightning fund to us, that is only possible if someone fills
2370 // nearly a full block with garbage just to hit this case.
2373 if outp.script_pubkey == self.destination_script {
2374 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2375 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2376 output: outp.clone(),
2379 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2380 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2381 spendable_output = Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2382 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2383 per_commitment_point: broadcasted_holder_revokable_script.1,
2384 to_self_delay: self.on_holder_tx_csv,
2385 output: outp.clone(),
2386 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2387 channel_keys_id: self.channel_keys_id,
2388 channel_value_satoshis: self.channel_value_satoshis,
2392 } else if self.counterparty_payment_script == outp.script_pubkey {
2393 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2394 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2395 output: outp.clone(),
2396 channel_keys_id: self.channel_keys_id,
2397 channel_value_satoshis: self.channel_value_satoshis,
2400 } else if outp.script_pubkey == self.shutdown_script {
2401 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2402 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2403 output: outp.clone(),
2407 if let Some(spendable_output) = spendable_output {
2408 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2409 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2410 hash_map::Entry::Occupied(mut entry) => {
2411 let e = entry.get_mut();
2412 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2414 hash_map::Entry::Vacant(entry) => {
2415 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2422 /// `Persist` defines behavior for persisting channel monitors: this could mean
2423 /// writing once to disk, and/or uploading to one or more backup services.
2425 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2426 /// to disk/backups. And, on every update, you **must** persist either the
2427 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2428 /// of situations such as revoking a transaction, then crashing before this
2429 /// revocation can be persisted, then unintentionally broadcasting a revoked
2430 /// transaction and losing money. This is a risk because previous channel states
2431 /// are toxic, so it's important that whatever channel state is persisted is
2432 /// kept up-to-date.
2433 pub trait Persist<ChannelSigner: Sign>: Send + Sync {
2434 /// Persist a new channel's data. The data can be stored any way you want, but
2435 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2436 /// it is up to you to maintain a correct mapping between the outpoint and the
2437 /// stored channel data). Note that you **must** persist every new monitor to
2438 /// disk. See the `Persist` trait documentation for more details.
2440 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2441 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2443 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2444 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2445 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2447 /// Update one channel's data. The provided `ChannelMonitor` has already
2448 /// applied the given update.
2450 /// Note that on every update, you **must** persist either the
2451 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2452 /// the `Persist` trait documentation for more details.
2454 /// If an implementer chooses to persist the updates only, they need to make
2455 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2456 /// the set of channel monitors is given to the `ChannelManager`
2457 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2458 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2459 /// persisted, then there is no need to persist individual updates.
2461 /// Note that there could be a performance tradeoff between persisting complete
2462 /// channel monitors on every update vs. persisting only updates and applying
2463 /// them in batches. The size of each monitor grows `O(number of state updates)`
2464 /// whereas updates are small and `O(1)`.
2466 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2467 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2468 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2470 /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
2471 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2472 /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
2473 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2474 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2477 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
2479 T::Target: BroadcasterInterface,
2480 F::Target: FeeEstimator,
2483 fn block_connected(&self, block: &Block, height: u32) {
2484 let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
2485 self.0.block_connected(&block.header, &txdata, height, &*self.1, &*self.2, &*self.3);
2488 fn block_disconnected(&self, header: &BlockHeader, height: u32) {
2489 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
2493 const MAX_ALLOC_SIZE: usize = 64*1024;
2495 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
2496 for (BlockHash, ChannelMonitor<Signer>) {
2497 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
2498 macro_rules! unwrap_obj {
2502 Err(_) => return Err(DecodeError::InvalidValue),
2507 let _ver: u8 = Readable::read(reader)?;
2508 let min_ver: u8 = Readable::read(reader)?;
2509 if min_ver > SERIALIZATION_VERSION {
2510 return Err(DecodeError::UnknownVersion);
2513 let latest_update_id: u64 = Readable::read(reader)?;
2514 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2516 let destination_script = Readable::read(reader)?;
2517 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2519 let revokable_address = Readable::read(reader)?;
2520 let per_commitment_point = Readable::read(reader)?;
2521 let revokable_script = Readable::read(reader)?;
2522 Some((revokable_address, per_commitment_point, revokable_script))
2525 _ => return Err(DecodeError::InvalidValue),
2527 let counterparty_payment_script = Readable::read(reader)?;
2528 let shutdown_script = Readable::read(reader)?;
2530 let channel_keys_id = Readable::read(reader)?;
2531 let holder_revocation_basepoint = Readable::read(reader)?;
2532 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2533 // barely-init'd ChannelMonitors that we can't do anything with.
2534 let outpoint = OutPoint {
2535 txid: Readable::read(reader)?,
2536 index: Readable::read(reader)?,
2538 let funding_info = (outpoint, Readable::read(reader)?);
2539 let current_counterparty_commitment_txid = Readable::read(reader)?;
2540 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2542 let counterparty_tx_cache = Readable::read(reader)?;
2543 let funding_redeemscript = Readable::read(reader)?;
2544 let channel_value_satoshis = Readable::read(reader)?;
2546 let their_cur_revocation_points = {
2547 let first_idx = <U48 as Readable>::read(reader)?.0;
2551 let first_point = Readable::read(reader)?;
2552 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2553 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2554 Some((first_idx, first_point, None))
2556 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2561 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2563 let commitment_secrets = Readable::read(reader)?;
2565 macro_rules! read_htlc_in_commitment {
2568 let offered: bool = Readable::read(reader)?;
2569 let amount_msat: u64 = Readable::read(reader)?;
2570 let cltv_expiry: u32 = Readable::read(reader)?;
2571 let payment_hash: PaymentHash = Readable::read(reader)?;
2572 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2574 HTLCOutputInCommitment {
2575 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2581 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2582 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2583 for _ in 0..counterparty_claimable_outpoints_len {
2584 let txid: Txid = Readable::read(reader)?;
2585 let htlcs_count: u64 = Readable::read(reader)?;
2586 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2587 for _ in 0..htlcs_count {
2588 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2590 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2591 return Err(DecodeError::InvalidValue);
2595 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2596 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2597 for _ in 0..counterparty_commitment_txn_on_chain_len {
2598 let txid: Txid = Readable::read(reader)?;
2599 let commitment_number = <U48 as Readable>::read(reader)?.0;
2600 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2601 return Err(DecodeError::InvalidValue);
2605 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2606 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2607 for _ in 0..counterparty_hash_commitment_number_len {
2608 let payment_hash: PaymentHash = Readable::read(reader)?;
2609 let commitment_number = <U48 as Readable>::read(reader)?.0;
2610 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2611 return Err(DecodeError::InvalidValue);
2615 macro_rules! read_holder_tx {
2618 let txid = Readable::read(reader)?;
2619 let revocation_key = Readable::read(reader)?;
2620 let a_htlc_key = Readable::read(reader)?;
2621 let b_htlc_key = Readable::read(reader)?;
2622 let delayed_payment_key = Readable::read(reader)?;
2623 let per_commitment_point = Readable::read(reader)?;
2624 let feerate_per_kw: u32 = Readable::read(reader)?;
2626 let htlcs_len: u64 = Readable::read(reader)?;
2627 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2628 for _ in 0..htlcs_len {
2629 let htlc = read_htlc_in_commitment!();
2630 let sigs = match <u8 as Readable>::read(reader)? {
2632 1 => Some(Readable::read(reader)?),
2633 _ => return Err(DecodeError::InvalidValue),
2635 htlcs.push((htlc, sigs, Readable::read(reader)?));
2640 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2647 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2650 Some(read_holder_tx!())
2652 _ => return Err(DecodeError::InvalidValue),
2654 let current_holder_commitment_tx = read_holder_tx!();
2656 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2657 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2659 let payment_preimages_len: u64 = Readable::read(reader)?;
2660 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2661 for _ in 0..payment_preimages_len {
2662 let preimage: PaymentPreimage = Readable::read(reader)?;
2663 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2664 if let Some(_) = payment_preimages.insert(hash, preimage) {
2665 return Err(DecodeError::InvalidValue);
2669 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2670 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2671 for _ in 0..pending_monitor_events_len {
2672 let ev = match <u8 as Readable>::read(reader)? {
2673 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2674 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2675 _ => return Err(DecodeError::InvalidValue)
2677 pending_monitor_events.push(ev);
2680 let pending_events_len: u64 = Readable::read(reader)?;
2681 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2682 for _ in 0..pending_events_len {
2683 if let Some(event) = MaybeReadable::read(reader)? {
2684 pending_events.push(event);
2688 let last_block_hash: BlockHash = Readable::read(reader)?;
2690 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2691 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2692 for _ in 0..waiting_threshold_conf_len {
2693 let height_target = Readable::read(reader)?;
2694 let events_len: u64 = Readable::read(reader)?;
2695 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2696 for _ in 0..events_len {
2697 let ev = match <u8 as Readable>::read(reader)? {
2699 let htlc_source = Readable::read(reader)?;
2700 let hash = Readable::read(reader)?;
2701 OnchainEvent::HTLCUpdate {
2702 htlc_update: (htlc_source, hash)
2706 let descriptor = Readable::read(reader)?;
2707 OnchainEvent::MaturingOutput {
2711 _ => return Err(DecodeError::InvalidValue),
2715 onchain_events_waiting_threshold_conf.insert(height_target, events);
2718 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2719 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>>())));
2720 for _ in 0..outputs_to_watch_len {
2721 let txid = Readable::read(reader)?;
2722 let outputs_len: u64 = Readable::read(reader)?;
2723 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2724 for _ in 0..outputs_len {
2725 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2727 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2728 return Err(DecodeError::InvalidValue);
2731 let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
2733 let lockdown_from_offchain = Readable::read(reader)?;
2734 let holder_tx_signed = Readable::read(reader)?;
2736 let mut secp_ctx = Secp256k1::new();
2737 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
2739 Ok((last_block_hash.clone(), ChannelMonitor {
2740 inner: Mutex::new(ChannelMonitorImpl {
2742 commitment_transaction_number_obscure_factor,
2745 broadcasted_holder_revokable_script,
2746 counterparty_payment_script,
2750 holder_revocation_basepoint,
2752 current_counterparty_commitment_txid,
2753 prev_counterparty_commitment_txid,
2755 counterparty_tx_cache,
2756 funding_redeemscript,
2757 channel_value_satoshis,
2758 their_cur_revocation_points,
2763 counterparty_claimable_outpoints,
2764 counterparty_commitment_txn_on_chain,
2765 counterparty_hash_commitment_number,
2767 prev_holder_signed_commitment_tx,
2768 current_holder_commitment_tx,
2769 current_counterparty_commitment_number,
2770 current_holder_commitment_number,
2773 pending_monitor_events,
2776 onchain_events_waiting_threshold_conf,
2781 lockdown_from_offchain,
2793 use bitcoin::blockdata::constants::genesis_block;
2794 use bitcoin::blockdata::script::{Script, Builder};
2795 use bitcoin::blockdata::opcodes;
2796 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2797 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2798 use bitcoin::util::bip143;
2799 use bitcoin::hashes::Hash;
2800 use bitcoin::hashes::sha256::Hash as Sha256;
2801 use bitcoin::hashes::hex::FromHex;
2802 use bitcoin::hash_types::Txid;
2803 use bitcoin::network::constants::Network;
2805 use chain::channelmonitor::ChannelMonitor;
2806 use chain::transaction::OutPoint;
2807 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2808 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2810 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
2811 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2812 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2813 use bitcoin::secp256k1::Secp256k1;
2814 use std::sync::{Arc, Mutex};
2815 use chain::keysinterface::InMemorySigner;
2818 fn test_prune_preimages() {
2819 let secp_ctx = Secp256k1::new();
2820 let logger = Arc::new(TestLogger::new());
2821 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
2822 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
2824 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2825 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2827 let mut preimages = Vec::new();
2830 let preimage = PaymentPreimage([i; 32]);
2831 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2832 preimages.push((preimage, hash));
2836 macro_rules! preimages_slice_to_htlc_outputs {
2837 ($preimages_slice: expr) => {
2839 let mut res = Vec::new();
2840 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2841 res.push((HTLCOutputInCommitment {
2845 payment_hash: preimage.1.clone(),
2846 transaction_output_index: Some(idx as u32),
2853 macro_rules! preimages_to_holder_htlcs {
2854 ($preimages_slice: expr) => {
2856 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2857 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2863 macro_rules! test_preimages_exist {
2864 ($preimages_slice: expr, $monitor: expr) => {
2865 for preimage in $preimages_slice {
2866 assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
2871 let keys = InMemorySigner::new(
2873 SecretKey::from_slice(&[41; 32]).unwrap(),
2874 SecretKey::from_slice(&[41; 32]).unwrap(),
2875 SecretKey::from_slice(&[41; 32]).unwrap(),
2876 SecretKey::from_slice(&[41; 32]).unwrap(),
2877 SecretKey::from_slice(&[41; 32]).unwrap(),
2883 let counterparty_pubkeys = ChannelPublicKeys {
2884 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2885 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2886 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
2887 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
2888 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
2890 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
2891 let channel_parameters = ChannelTransactionParameters {
2892 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
2893 holder_selected_contest_delay: 66,
2894 is_outbound_from_holder: true,
2895 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
2896 pubkeys: counterparty_pubkeys,
2897 selected_contest_delay: 67,
2899 funding_outpoint: Some(funding_outpoint),
2901 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2903 let last_block_hash = genesis_block(Network::Testnet).block_hash();
2904 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
2905 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2906 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2907 &channel_parameters,
2908 Script::new(), 46, 0,
2909 HolderCommitmentTransaction::dummy(), last_block_hash);
2911 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2912 let dummy_txid = dummy_tx.txid();
2913 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2914 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2915 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2916 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2917 for &(ref preimage, ref hash) in preimages.iter() {
2918 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2921 // Now provide a secret, pruning preimages 10-15
2922 let mut secret = [0; 32];
2923 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2924 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2925 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
2926 test_preimages_exist!(&preimages[0..10], monitor);
2927 test_preimages_exist!(&preimages[15..20], monitor);
2929 // Now provide a further secret, pruning preimages 15-17
2930 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2931 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2932 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
2933 test_preimages_exist!(&preimages[0..10], monitor);
2934 test_preimages_exist!(&preimages[17..20], monitor);
2936 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2937 // previous commitment tx's preimages too
2938 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2939 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2940 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2941 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
2942 test_preimages_exist!(&preimages[0..10], monitor);
2943 test_preimages_exist!(&preimages[18..20], monitor);
2945 // But if we do it again, we'll prune 5-10
2946 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2947 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2948 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2949 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
2950 test_preimages_exist!(&preimages[0..5], monitor);
2954 fn test_claim_txn_weight_computation() {
2955 // We test Claim txn weight, knowing that we want expected weigth and
2956 // not actual case to avoid sigs and time-lock delays hell variances.
2958 let secp_ctx = Secp256k1::new();
2959 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2960 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2961 let mut sum_actual_sigs = 0;
2963 macro_rules! sign_input {
2964 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2965 let htlc = HTLCOutputInCommitment {
2966 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2968 cltv_expiry: 2 << 16,
2969 payment_hash: PaymentHash([1; 32]),
2970 transaction_output_index: Some($idx as u32),
2972 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2973 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2974 let sig = secp_ctx.sign(&sighash, &privkey);
2975 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2976 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2977 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2978 if *$input_type == InputDescriptors::RevokedOutput {
2979 $sighash_parts.access_witness($idx).push(vec!(1));
2980 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2981 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2982 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2983 $sighash_parts.access_witness($idx).push(vec![0]);
2985 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2987 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2988 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2989 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2990 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2994 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2995 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2997 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2998 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3000 claim_tx.input.push(TxIn {
3001 previous_output: BitcoinOutPoint {
3005 script_sig: Script::new(),
3006 sequence: 0xfffffffd,
3007 witness: Vec::new(),
3010 claim_tx.output.push(TxOut {
3011 script_pubkey: script_pubkey.clone(),
3014 let base_weight = claim_tx.get_weight();
3015 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
3017 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3018 for (idx, inp) in inputs_des.iter().enumerate() {
3019 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3022 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));
3024 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3025 claim_tx.input.clear();
3026 sum_actual_sigs = 0;
3028 claim_tx.input.push(TxIn {
3029 previous_output: BitcoinOutPoint {
3033 script_sig: Script::new(),
3034 sequence: 0xfffffffd,
3035 witness: Vec::new(),
3038 let base_weight = claim_tx.get_weight();
3039 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
3041 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3042 for (idx, inp) in inputs_des.iter().enumerate() {
3043 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3046 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));
3048 // Justice tx with 1 revoked HTLC-Success tx output
3049 claim_tx.input.clear();
3050 sum_actual_sigs = 0;
3051 claim_tx.input.push(TxIn {
3052 previous_output: BitcoinOutPoint {
3056 script_sig: Script::new(),
3057 sequence: 0xfffffffd,
3058 witness: Vec::new(),
3060 let base_weight = claim_tx.get_weight();
3061 let inputs_des = vec![InputDescriptors::RevokedOutput];
3063 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3064 for (idx, inp) in inputs_des.iter().enumerate() {
3065 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3068 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));
3071 // Further testing is done in the ChannelManager integration tests.