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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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::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};
44 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
45 use chain::transaction::{OutPoint, TransactionData};
46 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys, KeysInterface};
47 use util::logger::Logger;
48 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
50 use util::events::Event;
52 use std::collections::{HashMap, HashSet, hash_map};
57 /// An update generated by the underlying Channel itself which contains some new information the
58 /// ChannelMonitor should be made aware of.
59 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
62 pub struct ChannelMonitorUpdate {
63 pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
64 /// The sequence number of this update. Updates *must* be replayed in-order according to this
65 /// sequence number (and updates may panic if they are not). The update_id values are strictly
66 /// increasing and increase by one for each new update, with one exception specified below.
68 /// This sequence number is also used to track up to which points updates which returned
69 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
70 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
72 /// The only instance where update_id values are not strictly increasing is the case where we
73 /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
74 /// its docs for more details.
76 /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
81 /// (1) a channel has been force closed and
82 /// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
83 /// this channel's (the backward link's) broadcasted commitment transaction
84 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
85 /// with the update providing said payment preimage. No other update types are allowed after
87 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
89 impl Writeable for ChannelMonitorUpdate {
90 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
91 self.update_id.write(w)?;
92 (self.updates.len() as u64).write(w)?;
93 for update_step in self.updates.iter() {
94 update_step.write(w)?;
99 impl Readable for ChannelMonitorUpdate {
100 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
101 let update_id: u64 = Readable::read(r)?;
102 let len: u64 = Readable::read(r)?;
103 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
105 updates.push(Readable::read(r)?);
107 Ok(Self { update_id, updates })
111 /// An error enum representing a failure to persist a channel monitor update.
112 #[derive(Clone, Debug)]
113 pub enum ChannelMonitorUpdateErr {
114 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
115 /// our state failed, but is expected to succeed at some point in the future).
117 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
118 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
119 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
120 /// restore the channel to an operational state.
122 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
123 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
124 /// writing out the latest ChannelManager state.
126 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
127 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
128 /// to claim it on this channel) and those updates must be applied wherever they can be. At
129 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
130 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
131 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
134 /// Note that even if updates made after TemporaryFailure succeed you must still call
135 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
138 /// Note that the update being processed here will not be replayed for you when you call
139 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
140 /// with the persisted ChannelMonitor on your own local disk prior to returning a
141 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
142 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
145 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
146 /// remote location (with local copies persisted immediately), it is anticipated that all
147 /// updates will return TemporaryFailure until the remote copies could be updated.
149 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
150 /// different watchtower and cannot update with all watchtowers that were previously informed
151 /// of this channel).
153 /// At reception of this error, ChannelManager will force-close the channel and return at
154 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
155 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
156 /// update must be rejected.
158 /// This failure may also signal a failure to update the local persisted copy of one of
159 /// the channel monitor instance.
161 /// Note that even when you fail a holder commitment transaction update, you must store the
162 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
163 /// broadcasts it (e.g distributed channel-monitor deployment)
165 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
166 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
167 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
168 /// lagging behind on block processing.
172 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
173 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
174 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
176 /// Contains a developer-readable error message.
178 pub struct MonitorUpdateError(pub &'static str);
180 /// An event to be processed by the ChannelManager.
181 #[derive(Clone, PartialEq)]
182 pub enum MonitorEvent {
183 /// A monitor event containing an HTLCUpdate.
184 HTLCEvent(HTLCUpdate),
186 /// A monitor event that the Channel's commitment transaction was broadcasted.
187 CommitmentTxBroadcasted(OutPoint),
190 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
191 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
192 /// preimage claim backward will lead to loss of funds.
194 /// [`chain::Watch`]: ../trait.Watch.html
195 #[derive(Clone, PartialEq)]
196 pub struct HTLCUpdate {
197 pub(crate) payment_hash: PaymentHash,
198 pub(crate) payment_preimage: Option<PaymentPreimage>,
199 pub(crate) source: HTLCSource
201 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
203 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
204 /// instead claiming it in its own individual transaction.
205 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
206 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
207 /// HTLC-Success transaction.
208 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
209 /// transaction confirmed (and we use it in a few more, equivalent, places).
210 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
211 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
212 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
213 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
214 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
215 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
216 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
217 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
218 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
219 /// accurate block height.
220 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
221 /// with at worst this delay, so we are not only using this value as a mercy for them but also
222 /// us as a safeguard to delay with enough time.
223 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
224 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
225 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
226 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
227 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
228 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
229 /// keeping bumping another claim tx to solve the outpoint.
230 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
231 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
232 /// refuse to accept a new HTLC.
234 /// This is used for a few separate purposes:
235 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
236 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
238 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
239 /// condition with the above), we will fail this HTLC without telling the user we received it,
240 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
241 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
243 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
244 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
246 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
247 /// in a race condition between the user connecting a block (which would fail it) and the user
248 /// providing us the preimage (which would claim it).
250 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
251 /// end up force-closing the channel on us to claim it.
252 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
254 // TODO(devrandom) replace this with HolderCommitmentTransaction
255 #[derive(Clone, PartialEq)]
256 struct HolderSignedTx {
257 /// txid of the transaction in tx, just used to make comparison faster
259 revocation_key: PublicKey,
260 a_htlc_key: PublicKey,
261 b_htlc_key: PublicKey,
262 delayed_payment_key: PublicKey,
263 per_commitment_point: PublicKey,
265 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
268 /// We use this to track counterparty commitment transactions and htlcs outputs and
269 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
271 struct CounterpartyCommitmentTransaction {
272 counterparty_delayed_payment_base_key: PublicKey,
273 counterparty_htlc_base_key: PublicKey,
274 on_counterparty_tx_csv: u16,
275 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
278 impl Writeable for CounterpartyCommitmentTransaction {
279 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
280 self.counterparty_delayed_payment_base_key.write(w)?;
281 self.counterparty_htlc_base_key.write(w)?;
282 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
283 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
284 for (ref txid, ref htlcs) in self.per_htlc.iter() {
285 w.write_all(&txid[..])?;
286 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
287 for &ref htlc in htlcs.iter() {
294 impl Readable for CounterpartyCommitmentTransaction {
295 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
296 let counterparty_commitment_transaction = {
297 let counterparty_delayed_payment_base_key = Readable::read(r)?;
298 let counterparty_htlc_base_key = Readable::read(r)?;
299 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
300 let per_htlc_len: u64 = Readable::read(r)?;
301 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
302 for _ in 0..per_htlc_len {
303 let txid: Txid = Readable::read(r)?;
304 let htlcs_count: u64 = Readable::read(r)?;
305 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
306 for _ in 0..htlcs_count {
307 let htlc = Readable::read(r)?;
310 if let Some(_) = per_htlc.insert(txid, htlcs) {
311 return Err(DecodeError::InvalidValue);
314 CounterpartyCommitmentTransaction {
315 counterparty_delayed_payment_base_key,
316 counterparty_htlc_base_key,
317 on_counterparty_tx_csv,
321 Ok(counterparty_commitment_transaction)
325 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
326 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
327 /// a new bumped one in case of lenghty confirmation delay
328 #[derive(Clone, PartialEq)]
329 pub(crate) enum InputMaterial {
331 per_commitment_point: PublicKey,
332 counterparty_delayed_payment_base_key: PublicKey,
333 counterparty_htlc_base_key: PublicKey,
334 per_commitment_key: SecretKey,
335 input_descriptor: InputDescriptors,
337 htlc: Option<HTLCOutputInCommitment>,
338 on_counterparty_tx_csv: u16,
341 per_commitment_point: PublicKey,
342 counterparty_delayed_payment_base_key: PublicKey,
343 counterparty_htlc_base_key: PublicKey,
344 preimage: Option<PaymentPreimage>,
345 htlc: HTLCOutputInCommitment
348 preimage: Option<PaymentPreimage>,
352 funding_redeemscript: Script,
356 impl Writeable for InputMaterial {
357 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
359 &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} => {
360 writer.write_all(&[0; 1])?;
361 per_commitment_point.write(writer)?;
362 counterparty_delayed_payment_base_key.write(writer)?;
363 counterparty_htlc_base_key.write(writer)?;
364 writer.write_all(&per_commitment_key[..])?;
365 input_descriptor.write(writer)?;
366 writer.write_all(&byte_utils::be64_to_array(*amount))?;
368 on_counterparty_tx_csv.write(writer)?;
370 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
371 writer.write_all(&[1; 1])?;
372 per_commitment_point.write(writer)?;
373 counterparty_delayed_payment_base_key.write(writer)?;
374 counterparty_htlc_base_key.write(writer)?;
375 preimage.write(writer)?;
378 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
379 writer.write_all(&[2; 1])?;
380 preimage.write(writer)?;
381 writer.write_all(&byte_utils::be64_to_array(*amount))?;
383 &InputMaterial::Funding { ref funding_redeemscript } => {
384 writer.write_all(&[3; 1])?;
385 funding_redeemscript.write(writer)?;
392 impl Readable for InputMaterial {
393 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
394 let input_material = match <u8 as Readable>::read(reader)? {
396 let per_commitment_point = Readable::read(reader)?;
397 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
398 let counterparty_htlc_base_key = Readable::read(reader)?;
399 let per_commitment_key = Readable::read(reader)?;
400 let input_descriptor = Readable::read(reader)?;
401 let amount = Readable::read(reader)?;
402 let htlc = Readable::read(reader)?;
403 let on_counterparty_tx_csv = Readable::read(reader)?;
404 InputMaterial::Revoked {
405 per_commitment_point,
406 counterparty_delayed_payment_base_key,
407 counterparty_htlc_base_key,
412 on_counterparty_tx_csv
416 let per_commitment_point = Readable::read(reader)?;
417 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
418 let counterparty_htlc_base_key = Readable::read(reader)?;
419 let preimage = Readable::read(reader)?;
420 let htlc = Readable::read(reader)?;
421 InputMaterial::CounterpartyHTLC {
422 per_commitment_point,
423 counterparty_delayed_payment_base_key,
424 counterparty_htlc_base_key,
430 let preimage = Readable::read(reader)?;
431 let amount = Readable::read(reader)?;
432 InputMaterial::HolderHTLC {
438 InputMaterial::Funding {
439 funding_redeemscript: Readable::read(reader)?,
442 _ => return Err(DecodeError::InvalidValue),
448 /// ClaimRequest is a descriptor structure to communicate between detection
449 /// and reaction module. They are generated by ChannelMonitor while parsing
450 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
451 /// is responsible for opportunistic aggregation, selecting and enforcing
452 /// bumping logic, building and signing transactions.
453 pub(crate) struct ClaimRequest {
454 // Block height before which claiming is exclusive to one party,
455 // after reaching it, claiming may be contentious.
456 pub(crate) absolute_timelock: u32,
457 // Timeout tx must have nLocktime set which means aggregating multiple
458 // ones must take the higher nLocktime among them to satisfy all of them.
459 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
460 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
461 // Do simplify we mark them as non-aggregable.
462 pub(crate) aggregable: bool,
463 // Basic bitcoin outpoint (txid, vout)
464 pub(crate) outpoint: BitcoinOutPoint,
465 // Following outpoint type, set of data needed to generate transaction digest
466 // and satisfy witness program.
467 pub(crate) witness_data: InputMaterial
470 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
471 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
472 #[derive(Clone, PartialEq)]
474 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
475 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
476 /// only win from it, so it's never an OnchainEvent
478 htlc_update: (HTLCSource, PaymentHash),
481 descriptor: SpendableOutputDescriptor,
485 const SERIALIZATION_VERSION: u8 = 1;
486 const MIN_SERIALIZATION_VERSION: u8 = 1;
488 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
490 pub(crate) enum ChannelMonitorUpdateStep {
491 LatestHolderCommitmentTXInfo {
492 commitment_tx: HolderCommitmentTransaction,
493 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
495 LatestCounterpartyCommitmentTXInfo {
496 commitment_txid: Txid,
497 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
498 commitment_number: u64,
499 their_revocation_point: PublicKey,
502 payment_preimage: PaymentPreimage,
508 /// Used to indicate that the no future updates will occur, and likely that the latest holder
509 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
511 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
512 /// think we've fallen behind!
513 should_broadcast: bool,
517 impl Writeable for ChannelMonitorUpdateStep {
518 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
520 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
522 commitment_tx.write(w)?;
523 (htlc_outputs.len() as u64).write(w)?;
524 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
530 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
532 commitment_txid.write(w)?;
533 commitment_number.write(w)?;
534 their_revocation_point.write(w)?;
535 (htlc_outputs.len() as u64).write(w)?;
536 for &(ref output, ref source) in htlc_outputs.iter() {
538 source.as_ref().map(|b| b.as_ref()).write(w)?;
541 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
543 payment_preimage.write(w)?;
545 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
550 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
552 should_broadcast.write(w)?;
558 impl Readable for ChannelMonitorUpdateStep {
559 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
560 match Readable::read(r)? {
562 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
563 commitment_tx: Readable::read(r)?,
565 let len: u64 = Readable::read(r)?;
566 let mut res = Vec::new();
568 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
575 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
576 commitment_txid: Readable::read(r)?,
577 commitment_number: Readable::read(r)?,
578 their_revocation_point: Readable::read(r)?,
580 let len: u64 = Readable::read(r)?;
581 let mut res = Vec::new();
583 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
590 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
591 payment_preimage: Readable::read(r)?,
595 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
596 idx: Readable::read(r)?,
597 secret: Readable::read(r)?,
601 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
602 should_broadcast: Readable::read(r)?
605 _ => Err(DecodeError::InvalidValue),
610 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
611 /// on-chain transactions to ensure no loss of funds occurs.
613 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
614 /// information and are actively monitoring the chain.
616 /// Pending Events or updated HTLCs which have not yet been read out by
617 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
618 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
619 /// gotten are fully handled before re-serializing the new state.
621 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
622 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
623 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
624 /// returned block hash and the the current chain and then reconnecting blocks to get to the
625 /// best chain) upon deserializing the object!
626 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
627 latest_update_id: u64,
628 commitment_transaction_number_obscure_factor: u64,
630 destination_script: Script,
631 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
632 counterparty_payment_script: Script,
633 shutdown_script: Script,
635 key_derivation_params: (u64, u64),
636 holder_revocation_basepoint: PublicKey,
637 funding_info: (OutPoint, Script),
638 current_counterparty_commitment_txid: Option<Txid>,
639 prev_counterparty_commitment_txid: Option<Txid>,
641 counterparty_tx_cache: CounterpartyCommitmentTransaction,
642 funding_redeemscript: Script,
643 channel_value_satoshis: u64,
644 // first is the idx of the first of the two revocation points
645 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
647 on_holder_tx_csv: u16,
649 commitment_secrets: CounterpartyCommitmentSecrets,
650 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
651 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
652 /// Nor can we figure out their commitment numbers without the commitment transaction they are
653 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
654 /// commitment transactions which we find on-chain, mapping them to the commitment number which
655 /// can be used to derive the revocation key and claim the transactions.
656 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
657 /// Cache used to make pruning of payment_preimages faster.
658 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
659 /// counterparty transactions (ie should remain pretty small).
660 /// Serialized to disk but should generally not be sent to Watchtowers.
661 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
663 // We store two holder commitment transactions to avoid any race conditions where we may update
664 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
665 // various monitors for one channel being out of sync, and us broadcasting a holder
666 // transaction for which we have deleted claim information on some watchtowers.
667 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
668 current_holder_commitment_tx: HolderSignedTx,
670 // Used just for ChannelManager to make sure it has the latest channel data during
672 current_counterparty_commitment_number: u64,
673 // Used just for ChannelManager to make sure it has the latest channel data during
675 current_holder_commitment_number: u64,
677 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
679 pending_monitor_events: Vec<MonitorEvent>,
680 pending_events: Vec<Event>,
682 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
683 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
684 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
685 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
687 // If we get serialized out and re-read, we need to make sure that the chain monitoring
688 // interface knows about the TXOs that we want to be notified of spends of. We could probably
689 // be smart and derive them from the above storage fields, but its much simpler and more
690 // Obviously Correct (tm) if we just keep track of them explicitly.
691 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
694 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
696 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
698 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
699 // channel has been force-closed. After this is set, no further holder commitment transaction
700 // updates may occur, and we panic!() if one is provided.
701 lockdown_from_offchain: bool,
703 // Set once we've signed a holder commitment transaction and handed it over to our
704 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
705 // may occur, and we fail any such monitor updates.
707 // In case of update rejection due to a locally already signed commitment transaction, we
708 // nevertheless store update content to track in case of concurrent broadcast by another
709 // remote monitor out-of-order with regards to the block view.
710 holder_tx_signed: bool,
712 // We simply modify last_block_hash in Channel's block_connected so that serialization is
713 // consistent but hopefully the users' copy handles block_connected in a consistent way.
714 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
715 // their last_block_hash from its state and not based on updated copies that didn't run through
716 // the full block_connected).
717 last_block_hash: BlockHash,
718 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
721 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
722 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
723 /// underlying object
724 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
725 fn eq(&self, other: &Self) -> bool {
726 if self.latest_update_id != other.latest_update_id ||
727 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
728 self.destination_script != other.destination_script ||
729 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
730 self.counterparty_payment_script != other.counterparty_payment_script ||
731 self.key_derivation_params != other.key_derivation_params ||
732 self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
733 self.funding_info != other.funding_info ||
734 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
735 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
736 self.counterparty_tx_cache != other.counterparty_tx_cache ||
737 self.funding_redeemscript != other.funding_redeemscript ||
738 self.channel_value_satoshis != other.channel_value_satoshis ||
739 self.their_cur_revocation_points != other.their_cur_revocation_points ||
740 self.on_holder_tx_csv != other.on_holder_tx_csv ||
741 self.commitment_secrets != other.commitment_secrets ||
742 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
743 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
744 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
745 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
746 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
747 self.current_holder_commitment_number != other.current_holder_commitment_number ||
748 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
749 self.payment_preimages != other.payment_preimages ||
750 self.pending_monitor_events != other.pending_monitor_events ||
751 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
752 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
753 self.outputs_to_watch != other.outputs_to_watch ||
754 self.lockdown_from_offchain != other.lockdown_from_offchain ||
755 self.holder_tx_signed != other.holder_tx_signed
764 impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
765 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
766 //TODO: We still write out all the serialization here manually instead of using the fancy
767 //serialization framework we have, we should migrate things over to it.
768 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
769 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
771 self.latest_update_id.write(writer)?;
773 // Set in initial Channel-object creation, so should always be set by now:
774 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
776 self.destination_script.write(writer)?;
777 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
778 writer.write_all(&[0; 1])?;
779 broadcasted_holder_revokable_script.0.write(writer)?;
780 broadcasted_holder_revokable_script.1.write(writer)?;
781 broadcasted_holder_revokable_script.2.write(writer)?;
783 writer.write_all(&[1; 1])?;
786 self.counterparty_payment_script.write(writer)?;
787 self.shutdown_script.write(writer)?;
789 self.key_derivation_params.write(writer)?;
790 self.holder_revocation_basepoint.write(writer)?;
791 writer.write_all(&self.funding_info.0.txid[..])?;
792 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
793 self.funding_info.1.write(writer)?;
794 self.current_counterparty_commitment_txid.write(writer)?;
795 self.prev_counterparty_commitment_txid.write(writer)?;
797 self.counterparty_tx_cache.write(writer)?;
798 self.funding_redeemscript.write(writer)?;
799 self.channel_value_satoshis.write(writer)?;
801 match self.their_cur_revocation_points {
802 Some((idx, pubkey, second_option)) => {
803 writer.write_all(&byte_utils::be48_to_array(idx))?;
804 writer.write_all(&pubkey.serialize())?;
805 match second_option {
806 Some(second_pubkey) => {
807 writer.write_all(&second_pubkey.serialize())?;
810 writer.write_all(&[0; 33])?;
815 writer.write_all(&byte_utils::be48_to_array(0))?;
819 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
821 self.commitment_secrets.write(writer)?;
823 macro_rules! serialize_htlc_in_commitment {
824 ($htlc_output: expr) => {
825 writer.write_all(&[$htlc_output.offered as u8; 1])?;
826 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
827 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
828 writer.write_all(&$htlc_output.payment_hash.0[..])?;
829 $htlc_output.transaction_output_index.write(writer)?;
833 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
834 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
835 writer.write_all(&txid[..])?;
836 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
837 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
838 serialize_htlc_in_commitment!(htlc_output);
839 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
843 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
844 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
845 writer.write_all(&txid[..])?;
846 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
849 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
850 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
851 writer.write_all(&payment_hash.0[..])?;
852 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
855 macro_rules! serialize_holder_tx {
856 ($holder_tx: expr) => {
857 $holder_tx.txid.write(writer)?;
858 writer.write_all(&$holder_tx.revocation_key.serialize())?;
859 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
860 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
861 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
862 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
864 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
865 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
866 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
867 serialize_htlc_in_commitment!(htlc_output);
868 if let &Some(ref their_sig) = sig {
870 writer.write_all(&their_sig.serialize_compact())?;
874 htlc_source.write(writer)?;
879 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
880 writer.write_all(&[1; 1])?;
881 serialize_holder_tx!(prev_holder_tx);
883 writer.write_all(&[0; 1])?;
886 serialize_holder_tx!(self.current_holder_commitment_tx);
888 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
889 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
891 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
892 for payment_preimage in self.payment_preimages.values() {
893 writer.write_all(&payment_preimage.0[..])?;
896 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
897 for event in self.pending_monitor_events.iter() {
899 MonitorEvent::HTLCEvent(upd) => {
903 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
907 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
908 for event in self.pending_events.iter() {
909 event.write(writer)?;
912 self.last_block_hash.write(writer)?;
914 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
915 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
916 writer.write_all(&byte_utils::be32_to_array(**target))?;
917 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
918 for ev in events.iter() {
920 OnchainEvent::HTLCUpdate { ref htlc_update } => {
922 htlc_update.0.write(writer)?;
923 htlc_update.1.write(writer)?;
925 OnchainEvent::MaturingOutput { ref descriptor } => {
927 descriptor.write(writer)?;
933 (self.outputs_to_watch.len() as u64).write(writer)?;
934 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
936 (idx_scripts.len() as u64).write(writer)?;
937 for (idx, script) in idx_scripts.iter() {
939 script.write(writer)?;
942 self.onchain_tx_handler.write(writer)?;
944 self.lockdown_from_offchain.write(writer)?;
945 self.holder_tx_signed.write(writer)?;
951 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
952 pub(crate) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
953 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
954 channel_parameters: &ChannelTransactionParameters,
955 funding_redeemscript: Script, channel_value_satoshis: u64,
956 commitment_transaction_number_obscure_factor: u64,
957 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
959 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
960 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
961 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
962 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
963 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
965 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
966 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
967 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
968 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
970 let key_derivation_params = keys.key_derivation_params();
971 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
972 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys, channel_parameters.clone());
974 let secp_ctx = Secp256k1::new();
976 // block for Rust 1.34 compat
977 let (holder_commitment_tx, current_holder_commitment_number) = {
978 let trusted_tx = initial_holder_commitment_tx.trust();
979 let txid = trusted_tx.txid();
981 let tx_keys = trusted_tx.keys();
982 let holder_commitment_tx = HolderSignedTx {
984 revocation_key: tx_keys.revocation_key,
985 a_htlc_key: tx_keys.broadcaster_htlc_key,
986 b_htlc_key: tx_keys.countersignatory_htlc_key,
987 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
988 per_commitment_point: tx_keys.per_commitment_point,
989 feerate_per_kw: trusted_tx.feerate_per_kw(),
990 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
992 (holder_commitment_tx, trusted_tx.commitment_number())
994 onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx);
996 let mut outputs_to_watch = HashMap::new();
997 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1000 latest_update_id: 0,
1001 commitment_transaction_number_obscure_factor,
1003 destination_script: destination_script.clone(),
1004 broadcasted_holder_revokable_script: None,
1005 counterparty_payment_script,
1008 key_derivation_params,
1009 holder_revocation_basepoint,
1011 current_counterparty_commitment_txid: None,
1012 prev_counterparty_commitment_txid: None,
1014 counterparty_tx_cache,
1015 funding_redeemscript,
1016 channel_value_satoshis,
1017 their_cur_revocation_points: None,
1019 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1021 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1022 counterparty_claimable_outpoints: HashMap::new(),
1023 counterparty_commitment_txn_on_chain: HashMap::new(),
1024 counterparty_hash_commitment_number: HashMap::new(),
1026 prev_holder_signed_commitment_tx: None,
1027 current_holder_commitment_tx: holder_commitment_tx,
1028 current_counterparty_commitment_number: 1 << 48,
1029 current_holder_commitment_number,
1031 payment_preimages: HashMap::new(),
1032 pending_monitor_events: Vec::new(),
1033 pending_events: Vec::new(),
1035 onchain_events_waiting_threshold_conf: HashMap::new(),
1040 lockdown_from_offchain: false,
1041 holder_tx_signed: false,
1043 last_block_hash: Default::default(),
1048 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1049 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1050 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1051 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1052 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1053 return Err(MonitorUpdateError("Previous secret did not match new one"));
1056 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1057 // events for now-revoked/fulfilled HTLCs.
1058 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1059 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1064 if !self.payment_preimages.is_empty() {
1065 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1066 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1067 let min_idx = self.get_min_seen_secret();
1068 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1070 self.payment_preimages.retain(|&k, _| {
1071 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1072 if k == htlc.payment_hash {
1076 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1077 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1078 if k == htlc.payment_hash {
1083 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1090 counterparty_hash_commitment_number.remove(&k);
1099 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1100 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1101 /// possibly future revocation/preimage information) to claim outputs where possible.
1102 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1103 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 {
1104 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1105 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1106 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1108 for &(ref htlc, _) in &htlc_outputs {
1109 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1112 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1113 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1114 self.current_counterparty_commitment_txid = Some(txid);
1115 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1116 self.current_counterparty_commitment_number = commitment_number;
1117 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1118 match self.their_cur_revocation_points {
1119 Some(old_points) => {
1120 if old_points.0 == commitment_number + 1 {
1121 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1122 } else if old_points.0 == commitment_number + 2 {
1123 if let Some(old_second_point) = old_points.2 {
1124 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1126 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1129 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1133 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1136 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1137 for htlc in htlc_outputs {
1138 if htlc.0.transaction_output_index.is_some() {
1142 self.counterparty_tx_cache.per_htlc.insert(txid, htlcs);
1145 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1146 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1147 /// is important that any clones of this channel monitor (including remote clones) by kept
1148 /// up-to-date as our holder commitment transaction is updated.
1149 /// Panics if set_on_holder_tx_csv has never been called.
1150 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1151 // block for Rust 1.34 compat
1152 let mut new_holder_commitment_tx = {
1153 let trusted_tx = holder_commitment_tx.trust();
1154 let txid = trusted_tx.txid();
1155 let tx_keys = trusted_tx.keys();
1156 self.current_holder_commitment_number = trusted_tx.commitment_number();
1159 revocation_key: tx_keys.revocation_key,
1160 a_htlc_key: tx_keys.broadcaster_htlc_key,
1161 b_htlc_key: tx_keys.countersignatory_htlc_key,
1162 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1163 per_commitment_point: tx_keys.per_commitment_point,
1164 feerate_per_kw: trusted_tx.feerate_per_kw(),
1168 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1169 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1170 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1171 if self.holder_tx_signed {
1172 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1177 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1178 /// commitment_tx_infos which contain the payment hash have been revoked.
1179 pub(crate) 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)
1180 where B::Target: BroadcasterInterface,
1181 F::Target: FeeEstimator,
1184 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1186 // If the channel is force closed, try to claim the output from this preimage.
1187 // First check if a counterparty commitment transaction has been broadcasted:
1188 macro_rules! claim_htlcs {
1189 ($commitment_number: expr, $txid: expr) => {
1190 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1191 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, None, broadcaster, fee_estimator, logger);
1194 if let Some(txid) = self.current_counterparty_commitment_txid {
1195 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1196 claim_htlcs!(*commitment_number, txid);
1200 if let Some(txid) = self.prev_counterparty_commitment_txid {
1201 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1202 claim_htlcs!(*commitment_number, txid);
1207 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1208 // claiming the HTLC output from each of the holder commitment transactions.
1209 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1210 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1211 // holder commitment transactions.
1212 if self.broadcasted_holder_revokable_script.is_some() {
1213 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1214 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1215 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1216 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx);
1217 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1222 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1223 where B::Target: BroadcasterInterface,
1226 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1227 broadcaster.broadcast_transaction(tx);
1229 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1232 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1235 /// panics if the given update is not the next update by update_id.
1236 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1237 where B::Target: BroadcasterInterface,
1238 F::Target: FeeEstimator,
1241 // ChannelMonitor updates may be applied after force close if we receive a
1242 // preimage for a broadcasted commitment transaction HTLC output that we'd
1243 // like to claim on-chain. If this is the case, we no longer have guaranteed
1244 // access to the monitor's update ID, so we use a sentinel value instead.
1245 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1246 match updates.updates[0] {
1247 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1248 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1250 assert_eq!(updates.updates.len(), 1);
1251 } else if self.latest_update_id + 1 != updates.update_id {
1252 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1254 for update in updates.updates.iter() {
1256 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1257 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1258 if self.lockdown_from_offchain { panic!(); }
1259 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1261 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1262 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1263 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1265 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1266 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1267 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1269 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1270 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1271 self.provide_secret(*idx, *secret)?
1273 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1274 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1275 self.lockdown_from_offchain = true;
1276 if *should_broadcast {
1277 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1279 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");
1284 self.latest_update_id = updates.update_id;
1288 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1290 pub fn get_latest_update_id(&self) -> u64 {
1291 self.latest_update_id
1294 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1295 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1299 /// Gets a list of txids, with their output scripts (in the order they appear in the
1300 /// transaction), which we must learn about spends of via block_connected().
1302 /// (C-not exported) because we have no HashMap bindings
1303 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1304 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1305 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1306 // its trivial to do, double-check that here.
1307 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1308 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1310 &self.outputs_to_watch
1313 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1314 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1316 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
1317 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1318 let mut ret = Vec::new();
1319 mem::swap(&mut ret, &mut self.pending_monitor_events);
1323 /// Gets the list of pending events which were generated by previous actions, clearing the list
1326 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1327 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1328 /// no internal locking in ChannelMonitors.
1329 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1330 let mut ret = Vec::new();
1331 mem::swap(&mut ret, &mut self.pending_events);
1335 /// Can only fail if idx is < get_min_seen_secret
1336 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1337 self.commitment_secrets.get_secret(idx)
1340 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1341 self.commitment_secrets.get_min_seen_secret()
1344 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1345 self.current_counterparty_commitment_number
1348 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1349 self.current_holder_commitment_number
1352 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1353 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1354 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1355 /// HTLC-Success/HTLC-Timeout transactions.
1356 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1357 /// revoked counterparty commitment tx
1358 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 {
1359 // Most secp and related errors trying to create keys means we have no hope of constructing
1360 // a spend transaction...so we return no transactions to broadcast
1361 let mut claimable_outpoints = Vec::new();
1362 let mut watch_outputs = Vec::new();
1364 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1365 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1367 macro_rules! ignore_error {
1368 ( $thing : expr ) => {
1371 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1376 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);
1377 if commitment_number >= self.get_min_seen_secret() {
1378 let secret = self.get_secret(commitment_number).unwrap();
1379 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1380 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1381 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
1382 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));
1384 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1385 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1387 // First, process non-htlc outputs (to_holder & to_counterparty)
1388 for (idx, outp) in tx.output.iter().enumerate() {
1389 if outp.script_pubkey == revokeable_p2wsh {
1390 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};
1391 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});
1395 // Then, try to find revoked htlc outputs
1396 if let Some(ref per_commitment_data) = per_commitment_option {
1397 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1398 if let Some(transaction_output_index) = htlc.transaction_output_index {
1399 if transaction_output_index as usize >= tx.output.len() ||
1400 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1401 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1403 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};
1404 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1409 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1410 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1411 // We're definitely a counterparty commitment transaction!
1412 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1413 for (idx, outp) in tx.output.iter().enumerate() {
1414 watch_outputs.push((idx as u32, outp.clone()));
1416 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1418 macro_rules! check_htlc_fails {
1419 ($txid: expr, $commitment_tx: expr) => {
1420 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1421 for &(ref htlc, ref source_option) in outpoints.iter() {
1422 if let &Some(ref source) = source_option {
1423 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1424 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1425 hash_map::Entry::Occupied(mut entry) => {
1426 let e = entry.get_mut();
1427 e.retain(|ref event| {
1429 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1430 return htlc_update.0 != **source
1435 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1437 hash_map::Entry::Vacant(entry) => {
1438 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1446 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1447 check_htlc_fails!(txid, "current");
1449 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1450 check_htlc_fails!(txid, "counterparty");
1452 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1454 } else if let Some(per_commitment_data) = per_commitment_option {
1455 // While this isn't useful yet, there is a potential race where if a counterparty
1456 // revokes a state at the same time as the commitment transaction for that state is
1457 // confirmed, and the watchtower receives the block before the user, the user could
1458 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1459 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1460 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1462 for (idx, outp) in tx.output.iter().enumerate() {
1463 watch_outputs.push((idx as u32, outp.clone()));
1465 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1467 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1469 macro_rules! check_htlc_fails {
1470 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1471 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1472 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1473 if let &Some(ref source) = source_option {
1474 // Check if the HTLC is present in the commitment transaction that was
1475 // broadcast, but not if it was below the dust limit, which we should
1476 // fail backwards immediately as there is no way for us to learn the
1477 // payment_preimage.
1478 // Note that if the dust limit were allowed to change between
1479 // commitment transactions we'd want to be check whether *any*
1480 // broadcastable commitment transaction has the HTLC in it, but it
1481 // cannot currently change after channel initialization, so we don't
1483 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1484 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1488 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);
1489 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1490 hash_map::Entry::Occupied(mut entry) => {
1491 let e = entry.get_mut();
1492 e.retain(|ref event| {
1494 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1495 return htlc_update.0 != **source
1500 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1502 hash_map::Entry::Vacant(entry) => {
1503 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1511 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1512 check_htlc_fails!(txid, "current", 'current_loop);
1514 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1515 check_htlc_fails!(txid, "previous", 'prev_loop);
1518 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
1519 for req in htlc_claim_reqs {
1520 claimable_outpoints.push(req);
1524 (claimable_outpoints, (commitment_txid, watch_outputs))
1527 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<ClaimRequest> {
1528 let mut claims = Vec::new();
1529 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
1530 if let Some(revocation_points) = self.their_cur_revocation_points {
1531 let revocation_point_option =
1532 // If the counterparty commitment tx is the latest valid state, use their latest
1533 // per-commitment point
1534 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1535 else if let Some(point) = revocation_points.2.as_ref() {
1536 // If counterparty commitment tx is the state previous to the latest valid state, use
1537 // their previous per-commitment point (non-atomicity of revocation means it's valid for
1538 // them to temporarily have two valid commitment txns from our viewpoint)
1539 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1541 if let Some(revocation_point) = revocation_point_option {
1542 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
1543 if let Some(transaction_output_index) = htlc.transaction_output_index {
1544 if let Some(transaction) = tx {
1545 if transaction_output_index as usize >= transaction.output.len() ||
1546 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1547 return claims; // Corrupted per_commitment_data, fuck this user
1552 if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) {
1556 let aggregable = if !htlc.offered { false } else { true };
1557 if preimage.is_some() || !htlc.offered {
1558 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() };
1559 claims.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1569 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1570 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 {
1571 let htlc_txid = tx.txid();
1572 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1573 return (Vec::new(), None)
1576 macro_rules! ignore_error {
1577 ( $thing : expr ) => {
1580 Err(_) => return (Vec::new(), None)
1585 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1586 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1587 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1589 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1590 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 };
1591 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 });
1592 let outputs = vec![(0, tx.output[0].clone())];
1593 (claimable_outpoints, Some((htlc_txid, outputs)))
1596 // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can
1597 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1598 // script so we can detect whether a holder transaction has been seen on-chain.
1599 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Option<(Script, PublicKey, PublicKey)>) {
1600 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1602 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1603 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1605 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1606 if let Some(transaction_output_index) = htlc.transaction_output_index {
1607 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1608 witness_data: InputMaterial::HolderHTLC {
1609 preimage: if !htlc.offered {
1610 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1611 Some(preimage.clone())
1613 // We can't build an HTLC-Success transaction without the preimage
1617 amount: htlc.amount_msat,
1622 (claim_requests, broadcasted_holder_revokable_script)
1625 // Returns holder HTLC outputs to watch and react to in case of spending.
1626 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1627 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1628 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1629 if let Some(transaction_output_index) = htlc.transaction_output_index {
1630 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1636 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1637 /// revoked using data in holder_claimable_outpoints.
1638 /// Should not be used if check_spend_revoked_transaction succeeds.
1639 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 {
1640 let commitment_txid = tx.txid();
1641 let mut claim_requests = Vec::new();
1642 let mut watch_outputs = Vec::new();
1644 macro_rules! wait_threshold_conf {
1645 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1646 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1647 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1648 hash_map::Entry::Occupied(mut entry) => {
1649 let e = entry.get_mut();
1650 e.retain(|ref event| {
1652 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1653 return htlc_update.0 != $source
1658 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1660 hash_map::Entry::Vacant(entry) => {
1661 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1667 macro_rules! append_onchain_update {
1668 ($updates: expr, $to_watch: expr) => {
1669 claim_requests = $updates.0;
1670 self.broadcasted_holder_revokable_script = $updates.1;
1671 watch_outputs.append(&mut $to_watch);
1675 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1676 let mut is_holder_tx = false;
1678 if self.current_holder_commitment_tx.txid == commitment_txid {
1679 is_holder_tx = true;
1680 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1681 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1682 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1683 append_onchain_update!(res, to_watch);
1684 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1685 if holder_tx.txid == commitment_txid {
1686 is_holder_tx = true;
1687 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1688 let res = self.get_broadcasted_holder_claims(holder_tx);
1689 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1690 append_onchain_update!(res, to_watch);
1694 macro_rules! fail_dust_htlcs_after_threshold_conf {
1695 ($holder_tx: expr) => {
1696 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1697 if htlc.transaction_output_index.is_none() {
1698 if let &Some(ref source) = source {
1699 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1707 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1708 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1709 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1713 (claim_requests, (commitment_txid, watch_outputs))
1716 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1717 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1718 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1719 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1720 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1721 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1722 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1723 /// out-of-band the other node operator to coordinate with him if option is available to you.
1724 /// In any-case, choice is up to the user.
1725 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1726 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1727 self.holder_tx_signed = true;
1728 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1729 let txid = commitment_tx.txid();
1730 let mut res = vec![commitment_tx];
1731 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1732 if let Some(vout) = htlc.0.transaction_output_index {
1733 let preimage = if !htlc.0.offered {
1734 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1735 // We can't build an HTLC-Success transaction without the preimage
1739 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1740 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1745 // 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.
1746 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1752 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1753 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1754 /// revoked commitment transaction.
1755 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1756 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1757 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1758 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
1759 let txid = commitment_tx.txid();
1760 let mut res = vec![commitment_tx];
1761 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1762 if let Some(vout) = htlc.0.transaction_output_index {
1763 let preimage = if !htlc.0.offered {
1764 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1765 // We can't build an HTLC-Success transaction without the preimage
1769 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1770 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1780 /// Processes transactions in a newly connected block, which may result in any of the following:
1781 /// - update the monitor's state against resolved HTLCs
1782 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1783 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1784 /// - detect settled outputs for later spending
1785 /// - schedule and bump any in-flight claims
1787 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1788 /// [`get_outputs_to_watch`].
1790 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1791 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)>)>
1792 where B::Target: BroadcasterInterface,
1793 F::Target: FeeEstimator,
1796 let txn_matched = self.filter_block(txdata);
1797 for tx in &txn_matched {
1798 let mut output_val = 0;
1799 for out in tx.output.iter() {
1800 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1801 output_val += out.value;
1802 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1806 let block_hash = header.block_hash();
1807 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1809 let mut watch_outputs = Vec::new();
1810 let mut claimable_outpoints = Vec::new();
1811 for tx in &txn_matched {
1812 if tx.input.len() == 1 {
1813 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1814 // commitment transactions and HTLC transactions will all only ever have one input,
1815 // which is an easy way to filter out any potential non-matching txn for lazy
1817 let prevout = &tx.input[0].previous_output;
1818 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1819 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1820 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1821 if !new_outputs.1.is_empty() {
1822 watch_outputs.push(new_outputs);
1824 if new_outpoints.is_empty() {
1825 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1826 if !new_outputs.1.is_empty() {
1827 watch_outputs.push(new_outputs);
1829 claimable_outpoints.append(&mut new_outpoints);
1831 claimable_outpoints.append(&mut new_outpoints);
1834 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1835 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1836 claimable_outpoints.append(&mut new_outpoints);
1837 if let Some(new_outputs) = new_outputs_option {
1838 watch_outputs.push(new_outputs);
1843 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1844 // can also be resolved in a few other ways which can have more than one output. Thus,
1845 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1846 self.is_resolving_htlc_output(&tx, height, &logger);
1848 self.is_paying_spendable_output(&tx, height, &logger);
1850 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1851 if should_broadcast {
1852 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() }});
1854 if should_broadcast {
1855 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1856 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1857 self.holder_tx_signed = true;
1858 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1859 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
1860 if !new_outputs.is_empty() {
1861 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
1863 claimable_outpoints.append(&mut new_outpoints);
1866 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1869 OnchainEvent::HTLCUpdate { htlc_update } => {
1870 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1871 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1872 payment_hash: htlc_update.1,
1873 payment_preimage: None,
1874 source: htlc_update.0,
1877 OnchainEvent::MaturingOutput { descriptor } => {
1878 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1879 self.pending_events.push(Event::SpendableOutputs {
1880 outputs: vec![descriptor]
1887 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
1888 self.last_block_hash = block_hash;
1890 // Determine new outputs to watch by comparing against previously known outputs to watch,
1891 // updating the latter in the process.
1892 watch_outputs.retain(|&(ref txid, ref txouts)| {
1893 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
1894 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
1898 // If we see a transaction for which we registered outputs previously,
1899 // make sure the registered scriptpubkey at the expected index match
1900 // the actual transaction output one. We failed this case before #653.
1901 for tx in &txn_matched {
1902 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
1903 for idx_and_script in outputs.iter() {
1904 assert!((idx_and_script.0 as usize) < tx.output.len());
1905 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
1913 /// Determines if the disconnected block contained any transactions of interest and updates
1915 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
1916 where B::Target: BroadcasterInterface,
1917 F::Target: FeeEstimator,
1920 let block_hash = header.block_hash();
1921 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1923 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1925 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1926 //- maturing spendable output has transaction paying us has been disconnected
1929 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1931 self.last_block_hash = block_hash;
1934 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
1935 /// transactions thereof.
1936 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
1937 let mut matched_txn = HashSet::new();
1938 txdata.iter().filter(|&&(_, tx)| {
1939 let mut matches = self.spends_watched_output(tx);
1940 for input in tx.input.iter() {
1941 if matches { break; }
1942 if matched_txn.contains(&input.previous_output.txid) {
1947 matched_txn.insert(tx.txid());
1950 }).map(|(_, tx)| *tx).collect()
1953 /// Checks if a given transaction spends any watched outputs.
1954 fn spends_watched_output(&self, tx: &Transaction) -> bool {
1955 for input in tx.input.iter() {
1956 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
1957 for (idx, _script_pubkey) in outputs.iter() {
1958 if *idx == input.previous_output.vout {
1961 // If the expected script is a known type, check that the witness
1962 // appears to be spending the correct type (ie that the match would
1963 // actually succeed in BIP 158/159-style filters).
1964 if _script_pubkey.is_v0_p2wsh() {
1965 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
1966 } else if _script_pubkey.is_v0_p2wpkh() {
1967 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
1968 } else { panic!(); }
1979 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
1980 // We need to consider all HTLCs which are:
1981 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
1982 // transactions and we'd end up in a race, or
1983 // * are in our latest holder commitment transaction, as this is the thing we will
1984 // broadcast if we go on-chain.
1985 // Note that we consider HTLCs which were below dust threshold here - while they don't
1986 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1987 // to the source, and if we don't fail the channel we will have to ensure that the next
1988 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1989 // easier to just fail the channel as this case should be rare enough anyway.
1990 macro_rules! scan_commitment {
1991 ($htlcs: expr, $holder_tx: expr) => {
1992 for ref htlc in $htlcs {
1993 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1994 // chain with enough room to claim the HTLC without our counterparty being able to
1995 // time out the HTLC first.
1996 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1997 // concern is being able to claim the corresponding inbound HTLC (on another
1998 // channel) before it expires. In fact, we don't even really care if our
1999 // counterparty here claims such an outbound HTLC after it expired as long as we
2000 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2001 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2002 // we give ourselves a few blocks of headroom after expiration before going
2003 // on-chain for an expired HTLC.
2004 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2005 // from us until we've reached the point where we go on-chain with the
2006 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2007 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2008 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2009 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2010 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2011 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2012 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2013 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2014 // The final, above, condition is checked for statically in channelmanager
2015 // with CHECK_CLTV_EXPIRY_SANITY_2.
2016 let htlc_outbound = $holder_tx == htlc.offered;
2017 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2018 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2019 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2026 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2028 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2029 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2030 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2033 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2034 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2035 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2042 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2043 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2044 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2045 'outer_loop: for input in &tx.input {
2046 let mut payment_data = None;
2047 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2048 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2049 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2050 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2052 macro_rules! log_claim {
2053 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2054 // We found the output in question, but aren't failing it backwards
2055 // as we have no corresponding source and no valid counterparty commitment txid
2056 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2057 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2058 let outbound_htlc = $holder_tx == $htlc.offered;
2059 if ($holder_tx && revocation_sig_claim) ||
2060 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2061 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2062 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2063 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2064 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2066 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2067 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2068 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2069 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2074 macro_rules! check_htlc_valid_counterparty {
2075 ($counterparty_txid: expr, $htlc_output: expr) => {
2076 if let Some(txid) = $counterparty_txid {
2077 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2078 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2079 if let &Some(ref source) = pending_source {
2080 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2081 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2090 macro_rules! scan_commitment {
2091 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2092 for (ref htlc_output, source_option) in $htlcs {
2093 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2094 if let Some(ref source) = source_option {
2095 log_claim!($tx_info, $holder_tx, htlc_output, true);
2096 // We have a resolution of an HTLC either from one of our latest
2097 // holder commitment transactions or an unrevoked counterparty commitment
2098 // transaction. This implies we either learned a preimage, the HTLC
2099 // has timed out, or we screwed up. In any case, we should now
2100 // resolve the source HTLC with the original sender.
2101 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2102 } else if !$holder_tx {
2103 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2104 if payment_data.is_none() {
2105 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2108 if payment_data.is_none() {
2109 log_claim!($tx_info, $holder_tx, htlc_output, false);
2110 continue 'outer_loop;
2117 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2118 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2119 "our latest holder commitment tx", true);
2121 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2122 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2123 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2124 "our previous holder commitment tx", true);
2127 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2128 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2129 "counterparty commitment tx", false);
2132 // Check that scan_commitment, above, decided there is some source worth relaying an
2133 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2134 if let Some((source, payment_hash)) = payment_data {
2135 let mut payment_preimage = PaymentPreimage([0; 32]);
2136 if accepted_preimage_claim {
2137 if !self.pending_monitor_events.iter().any(
2138 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2139 payment_preimage.0.copy_from_slice(&input.witness[3]);
2140 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2142 payment_preimage: Some(payment_preimage),
2146 } else if offered_preimage_claim {
2147 if !self.pending_monitor_events.iter().any(
2148 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2149 upd.source == source
2151 payment_preimage.0.copy_from_slice(&input.witness[1]);
2152 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2154 payment_preimage: Some(payment_preimage),
2159 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);
2160 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2161 hash_map::Entry::Occupied(mut entry) => {
2162 let e = entry.get_mut();
2163 e.retain(|ref event| {
2165 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2166 return htlc_update.0 != source
2171 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2173 hash_map::Entry::Vacant(entry) => {
2174 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2182 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2183 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2184 let mut spendable_output = None;
2185 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2186 if i > ::std::u16::MAX as usize {
2187 // While it is possible that an output exists on chain which is greater than the
2188 // 2^16th output in a given transaction, this is only possible if the output is not
2189 // in a lightning transaction and was instead placed there by some third party who
2190 // wishes to give us money for no reason.
2191 // Namely, any lightning transactions which we pre-sign will never have anywhere
2192 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2193 // scripts are not longer than one byte in length and because they are inherently
2194 // non-standard due to their size.
2195 // Thus, it is completely safe to ignore such outputs, and while it may result in
2196 // us ignoring non-lightning fund to us, that is only possible if someone fills
2197 // nearly a full block with garbage just to hit this case.
2200 if outp.script_pubkey == self.destination_script {
2201 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2202 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2203 output: outp.clone(),
2206 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2207 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2208 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2209 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2210 per_commitment_point: broadcasted_holder_revokable_script.1,
2211 to_self_delay: self.on_holder_tx_csv,
2212 output: outp.clone(),
2213 key_derivation_params: self.key_derivation_params,
2214 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2218 } else if self.counterparty_payment_script == outp.script_pubkey {
2219 spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
2220 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2221 output: outp.clone(),
2222 key_derivation_params: self.key_derivation_params,
2225 } else if outp.script_pubkey == self.shutdown_script {
2226 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2227 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2228 output: outp.clone(),
2232 if let Some(spendable_output) = spendable_output {
2233 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2234 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2235 hash_map::Entry::Occupied(mut entry) => {
2236 let e = entry.get_mut();
2237 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2239 hash_map::Entry::Vacant(entry) => {
2240 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2247 /// `Persist` defines behavior for persisting channel monitors: this could mean
2248 /// writing once to disk, and/or uploading to one or more backup services.
2250 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2251 /// to disk/backups. And, on every update, you **must** persist either the
2252 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2253 /// of situations such as revoking a transaction, then crashing before this
2254 /// revocation can be persisted, then unintentionally broadcasting a revoked
2255 /// transaction and losing money. This is a risk because previous channel states
2256 /// are toxic, so it's important that whatever channel state is persisted is
2257 /// kept up-to-date.
2258 pub trait Persist<Keys: ChannelKeys>: Send + Sync {
2259 /// Persist a new channel's data. The data can be stored any way you want, but
2260 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2261 /// it is up to you to maintain a correct mapping between the outpoint and the
2262 /// stored channel data). Note that you **must** persist every new monitor to
2263 /// disk. See the `Persist` trait documentation for more details.
2265 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2266 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2268 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2269 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2270 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
2272 /// Update one channel's data. The provided `ChannelMonitor` has already
2273 /// applied the given update.
2275 /// Note that on every update, you **must** persist either the
2276 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2277 /// the `Persist` trait documentation for more details.
2279 /// If an implementer chooses to persist the updates only, they need to make
2280 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2281 /// the set of channel monitors is given to the `ChannelManager`
2282 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2283 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2284 /// persisted, then there is no need to persist individual updates.
2286 /// Note that there could be a performance tradeoff between persisting complete
2287 /// channel monitors on every update vs. persisting only updates and applying
2288 /// them in batches. The size of each monitor grows `O(number of state updates)`
2289 /// whereas updates are small and `O(1)`.
2291 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2292 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2293 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2295 /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
2296 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2297 /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
2298 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2299 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
2302 const MAX_ALLOC_SIZE: usize = 64*1024;
2304 impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>> ReadableArgs<&'a K>
2305 for (BlockHash, ChannelMonitor<ChanSigner>) {
2306 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
2307 macro_rules! unwrap_obj {
2311 Err(_) => return Err(DecodeError::InvalidValue),
2316 let _ver: u8 = Readable::read(reader)?;
2317 let min_ver: u8 = Readable::read(reader)?;
2318 if min_ver > SERIALIZATION_VERSION {
2319 return Err(DecodeError::UnknownVersion);
2322 let latest_update_id: u64 = Readable::read(reader)?;
2323 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2325 let destination_script = Readable::read(reader)?;
2326 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2328 let revokable_address = Readable::read(reader)?;
2329 let per_commitment_point = Readable::read(reader)?;
2330 let revokable_script = Readable::read(reader)?;
2331 Some((revokable_address, per_commitment_point, revokable_script))
2334 _ => return Err(DecodeError::InvalidValue),
2336 let counterparty_payment_script = Readable::read(reader)?;
2337 let shutdown_script = Readable::read(reader)?;
2339 let key_derivation_params = Readable::read(reader)?;
2340 let holder_revocation_basepoint = Readable::read(reader)?;
2341 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2342 // barely-init'd ChannelMonitors that we can't do anything with.
2343 let outpoint = OutPoint {
2344 txid: Readable::read(reader)?,
2345 index: Readable::read(reader)?,
2347 let funding_info = (outpoint, Readable::read(reader)?);
2348 let current_counterparty_commitment_txid = Readable::read(reader)?;
2349 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2351 let counterparty_tx_cache = Readable::read(reader)?;
2352 let funding_redeemscript = Readable::read(reader)?;
2353 let channel_value_satoshis = Readable::read(reader)?;
2355 let their_cur_revocation_points = {
2356 let first_idx = <U48 as Readable>::read(reader)?.0;
2360 let first_point = Readable::read(reader)?;
2361 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2362 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2363 Some((first_idx, first_point, None))
2365 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2370 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2372 let commitment_secrets = Readable::read(reader)?;
2374 macro_rules! read_htlc_in_commitment {
2377 let offered: bool = Readable::read(reader)?;
2378 let amount_msat: u64 = Readable::read(reader)?;
2379 let cltv_expiry: u32 = Readable::read(reader)?;
2380 let payment_hash: PaymentHash = Readable::read(reader)?;
2381 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2383 HTLCOutputInCommitment {
2384 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2390 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2391 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2392 for _ in 0..counterparty_claimable_outpoints_len {
2393 let txid: Txid = Readable::read(reader)?;
2394 let htlcs_count: u64 = Readable::read(reader)?;
2395 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2396 for _ in 0..htlcs_count {
2397 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2399 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2400 return Err(DecodeError::InvalidValue);
2404 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2405 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2406 for _ in 0..counterparty_commitment_txn_on_chain_len {
2407 let txid: Txid = Readable::read(reader)?;
2408 let commitment_number = <U48 as Readable>::read(reader)?.0;
2409 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2410 return Err(DecodeError::InvalidValue);
2414 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2415 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2416 for _ in 0..counterparty_hash_commitment_number_len {
2417 let payment_hash: PaymentHash = Readable::read(reader)?;
2418 let commitment_number = <U48 as Readable>::read(reader)?.0;
2419 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2420 return Err(DecodeError::InvalidValue);
2424 macro_rules! read_holder_tx {
2427 let txid = Readable::read(reader)?;
2428 let revocation_key = Readable::read(reader)?;
2429 let a_htlc_key = Readable::read(reader)?;
2430 let b_htlc_key = Readable::read(reader)?;
2431 let delayed_payment_key = Readable::read(reader)?;
2432 let per_commitment_point = Readable::read(reader)?;
2433 let feerate_per_kw: u32 = Readable::read(reader)?;
2435 let htlcs_len: u64 = Readable::read(reader)?;
2436 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2437 for _ in 0..htlcs_len {
2438 let htlc = read_htlc_in_commitment!();
2439 let sigs = match <u8 as Readable>::read(reader)? {
2441 1 => Some(Readable::read(reader)?),
2442 _ => return Err(DecodeError::InvalidValue),
2444 htlcs.push((htlc, sigs, Readable::read(reader)?));
2449 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2456 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2459 Some(read_holder_tx!())
2461 _ => return Err(DecodeError::InvalidValue),
2463 let current_holder_commitment_tx = read_holder_tx!();
2465 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2466 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2468 let payment_preimages_len: u64 = Readable::read(reader)?;
2469 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2470 for _ in 0..payment_preimages_len {
2471 let preimage: PaymentPreimage = Readable::read(reader)?;
2472 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2473 if let Some(_) = payment_preimages.insert(hash, preimage) {
2474 return Err(DecodeError::InvalidValue);
2478 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2479 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2480 for _ in 0..pending_monitor_events_len {
2481 let ev = match <u8 as Readable>::read(reader)? {
2482 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2483 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2484 _ => return Err(DecodeError::InvalidValue)
2486 pending_monitor_events.push(ev);
2489 let pending_events_len: u64 = Readable::read(reader)?;
2490 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2491 for _ in 0..pending_events_len {
2492 if let Some(event) = MaybeReadable::read(reader)? {
2493 pending_events.push(event);
2497 let last_block_hash: BlockHash = Readable::read(reader)?;
2499 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2500 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2501 for _ in 0..waiting_threshold_conf_len {
2502 let height_target = Readable::read(reader)?;
2503 let events_len: u64 = Readable::read(reader)?;
2504 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2505 for _ in 0..events_len {
2506 let ev = match <u8 as Readable>::read(reader)? {
2508 let htlc_source = Readable::read(reader)?;
2509 let hash = Readable::read(reader)?;
2510 OnchainEvent::HTLCUpdate {
2511 htlc_update: (htlc_source, hash)
2515 let descriptor = Readable::read(reader)?;
2516 OnchainEvent::MaturingOutput {
2520 _ => return Err(DecodeError::InvalidValue),
2524 onchain_events_waiting_threshold_conf.insert(height_target, events);
2527 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2528 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>>())));
2529 for _ in 0..outputs_to_watch_len {
2530 let txid = Readable::read(reader)?;
2531 let outputs_len: u64 = Readable::read(reader)?;
2532 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2533 for _ in 0..outputs_len {
2534 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2536 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2537 return Err(DecodeError::InvalidValue);
2540 let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
2542 let lockdown_from_offchain = Readable::read(reader)?;
2543 let holder_tx_signed = Readable::read(reader)?;
2545 Ok((last_block_hash.clone(), ChannelMonitor {
2547 commitment_transaction_number_obscure_factor,
2550 broadcasted_holder_revokable_script,
2551 counterparty_payment_script,
2554 key_derivation_params,
2555 holder_revocation_basepoint,
2557 current_counterparty_commitment_txid,
2558 prev_counterparty_commitment_txid,
2560 counterparty_tx_cache,
2561 funding_redeemscript,
2562 channel_value_satoshis,
2563 their_cur_revocation_points,
2568 counterparty_claimable_outpoints,
2569 counterparty_commitment_txn_on_chain,
2570 counterparty_hash_commitment_number,
2572 prev_holder_signed_commitment_tx,
2573 current_holder_commitment_tx,
2574 current_counterparty_commitment_number,
2575 current_holder_commitment_number,
2578 pending_monitor_events,
2581 onchain_events_waiting_threshold_conf,
2586 lockdown_from_offchain,
2590 secp_ctx: Secp256k1::new(),
2597 use bitcoin::blockdata::script::{Script, Builder};
2598 use bitcoin::blockdata::opcodes;
2599 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2600 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2601 use bitcoin::util::bip143;
2602 use bitcoin::hashes::Hash;
2603 use bitcoin::hashes::sha256::Hash as Sha256;
2604 use bitcoin::hashes::hex::FromHex;
2605 use bitcoin::hash_types::Txid;
2607 use chain::channelmonitor::ChannelMonitor;
2608 use chain::transaction::OutPoint;
2609 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2610 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2612 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
2613 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2614 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2615 use bitcoin::secp256k1::Secp256k1;
2616 use std::sync::{Arc, Mutex};
2617 use chain::keysinterface::InMemoryChannelKeys;
2620 fn test_prune_preimages() {
2621 let secp_ctx = Secp256k1::new();
2622 let logger = Arc::new(TestLogger::new());
2623 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
2624 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
2626 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2627 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2629 let mut preimages = Vec::new();
2632 let preimage = PaymentPreimage([i; 32]);
2633 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2634 preimages.push((preimage, hash));
2638 macro_rules! preimages_slice_to_htlc_outputs {
2639 ($preimages_slice: expr) => {
2641 let mut res = Vec::new();
2642 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2643 res.push((HTLCOutputInCommitment {
2647 payment_hash: preimage.1.clone(),
2648 transaction_output_index: Some(idx as u32),
2655 macro_rules! preimages_to_holder_htlcs {
2656 ($preimages_slice: expr) => {
2658 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2659 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2665 macro_rules! test_preimages_exist {
2666 ($preimages_slice: expr, $monitor: expr) => {
2667 for preimage in $preimages_slice {
2668 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2673 let keys = InMemoryChannelKeys::new(
2675 SecretKey::from_slice(&[41; 32]).unwrap(),
2676 SecretKey::from_slice(&[41; 32]).unwrap(),
2677 SecretKey::from_slice(&[41; 32]).unwrap(),
2678 SecretKey::from_slice(&[41; 32]).unwrap(),
2679 SecretKey::from_slice(&[41; 32]).unwrap(),
2685 let counterparty_pubkeys = ChannelPublicKeys {
2686 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2687 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2688 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
2689 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
2690 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
2692 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
2693 let channel_parameters = ChannelTransactionParameters {
2694 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
2695 holder_selected_contest_delay: 66,
2696 is_outbound_from_holder: true,
2697 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
2698 pubkeys: counterparty_pubkeys,
2699 selected_contest_delay: 67,
2701 funding_outpoint: Some(funding_outpoint),
2703 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2705 let mut monitor = ChannelMonitor::new(keys,
2706 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2707 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2708 &channel_parameters,
2709 Script::new(), 46, 0,
2710 HolderCommitmentTransaction::dummy());
2712 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2713 let dummy_txid = dummy_tx.txid();
2714 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2715 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2716 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2717 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2718 for &(ref preimage, ref hash) in preimages.iter() {
2719 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2722 // Now provide a secret, pruning preimages 10-15
2723 let mut secret = [0; 32];
2724 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2725 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2726 assert_eq!(monitor.payment_preimages.len(), 15);
2727 test_preimages_exist!(&preimages[0..10], monitor);
2728 test_preimages_exist!(&preimages[15..20], monitor);
2730 // Now provide a further secret, pruning preimages 15-17
2731 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2732 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2733 assert_eq!(monitor.payment_preimages.len(), 13);
2734 test_preimages_exist!(&preimages[0..10], monitor);
2735 test_preimages_exist!(&preimages[17..20], monitor);
2737 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2738 // previous commitment tx's preimages too
2739 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2740 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2741 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2742 assert_eq!(monitor.payment_preimages.len(), 12);
2743 test_preimages_exist!(&preimages[0..10], monitor);
2744 test_preimages_exist!(&preimages[18..20], monitor);
2746 // But if we do it again, we'll prune 5-10
2747 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2748 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2749 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2750 assert_eq!(monitor.payment_preimages.len(), 5);
2751 test_preimages_exist!(&preimages[0..5], monitor);
2755 fn test_claim_txn_weight_computation() {
2756 // We test Claim txn weight, knowing that we want expected weigth and
2757 // not actual case to avoid sigs and time-lock delays hell variances.
2759 let secp_ctx = Secp256k1::new();
2760 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2761 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2762 let mut sum_actual_sigs = 0;
2764 macro_rules! sign_input {
2765 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2766 let htlc = HTLCOutputInCommitment {
2767 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2769 cltv_expiry: 2 << 16,
2770 payment_hash: PaymentHash([1; 32]),
2771 transaction_output_index: Some($idx as u32),
2773 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2774 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2775 let sig = secp_ctx.sign(&sighash, &privkey);
2776 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2777 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2778 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2779 if *$input_type == InputDescriptors::RevokedOutput {
2780 $sighash_parts.access_witness($idx).push(vec!(1));
2781 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2782 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2783 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2784 $sighash_parts.access_witness($idx).push(vec![0]);
2786 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2788 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2789 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2790 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2791 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2795 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2796 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2798 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2799 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2801 claim_tx.input.push(TxIn {
2802 previous_output: BitcoinOutPoint {
2806 script_sig: Script::new(),
2807 sequence: 0xfffffffd,
2808 witness: Vec::new(),
2811 claim_tx.output.push(TxOut {
2812 script_pubkey: script_pubkey.clone(),
2815 let base_weight = claim_tx.get_weight();
2816 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2818 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2819 for (idx, inp) in inputs_des.iter().enumerate() {
2820 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2823 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2825 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2826 claim_tx.input.clear();
2827 sum_actual_sigs = 0;
2829 claim_tx.input.push(TxIn {
2830 previous_output: BitcoinOutPoint {
2834 script_sig: Script::new(),
2835 sequence: 0xfffffffd,
2836 witness: Vec::new(),
2839 let base_weight = claim_tx.get_weight();
2840 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2842 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2843 for (idx, inp) in inputs_des.iter().enumerate() {
2844 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2847 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2849 // Justice tx with 1 revoked HTLC-Success tx output
2850 claim_tx.input.clear();
2851 sum_actual_sigs = 0;
2852 claim_tx.input.push(TxIn {
2853 previous_output: BitcoinOutPoint {
2857 script_sig: Script::new(),
2858 sequence: 0xfffffffd,
2859 witness: Vec::new(),
2861 let base_weight = claim_tx.get_weight();
2862 let inputs_des = vec![InputDescriptors::RevokedOutput];
2864 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2865 for (idx, inp) in inputs_des.iter().enumerate() {
2866 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2869 assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
2872 // Further testing is done in the ChannelManager integration tests.