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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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;
30 use bitcoin::consensus::encode;
32 use bitcoin::hashes::Hash;
33 use bitcoin::hashes::sha256::Hash as Sha256;
34 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
36 use bitcoin::secp256k1::{Secp256k1,Signature};
37 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
38 use bitcoin::secp256k1;
40 use ln::msgs::DecodeError;
42 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HolderCommitmentTransaction, HTLCType};
43 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
44 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
45 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
46 use chain::transaction::{OutPoint, TransactionData};
47 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
48 use util::logger::Logger;
49 use util::ser::{Readable, MaybeReadable, Writer, Writeable, U48};
51 use util::events::Event;
53 use std::collections::{HashMap, HashSet, hash_map};
58 /// An update generated by the underlying Channel itself which contains some new information the
59 /// ChannelMonitor should be made aware of.
60 #[cfg_attr(any(test, feature = "_test_utils"), derive(PartialEq))]
63 pub struct ChannelMonitorUpdate {
64 pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
65 /// The sequence number of this update. Updates *must* be replayed in-order according to this
66 /// sequence number (and updates may panic if they are not). The update_id values are strictly
67 /// increasing and increase by one for each new update, with one exception specified below.
69 /// This sequence number is also used to track up to which points updates which returned
70 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
71 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
73 /// The only instance where update_id values are not strictly increasing is the case where we
74 /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
75 /// its docs for more details.
77 /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
82 /// (1) a channel has been force closed and
83 /// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
84 /// this channel's (the backward link's) broadcasted commitment transaction
85 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
86 /// with the update providing said payment preimage. No other update types are allowed after
88 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
90 impl Writeable for ChannelMonitorUpdate {
91 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
92 self.update_id.write(w)?;
93 (self.updates.len() as u64).write(w)?;
94 for update_step in self.updates.iter() {
95 update_step.write(w)?;
100 impl Readable for ChannelMonitorUpdate {
101 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
102 let update_id: u64 = Readable::read(r)?;
103 let len: u64 = Readable::read(r)?;
104 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
106 updates.push(Readable::read(r)?);
108 Ok(Self { update_id, updates })
112 /// An error enum representing a failure to persist a channel monitor update.
113 #[derive(Clone, Debug)]
114 pub enum ChannelMonitorUpdateErr {
115 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
116 /// our state failed, but is expected to succeed at some point in the future).
118 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
119 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
120 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
121 /// restore the channel to an operational state.
123 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
124 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
125 /// writing out the latest ChannelManager state.
127 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
128 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
129 /// to claim it on this channel) and those updates must be applied wherever they can be. At
130 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
131 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
132 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
135 /// Note that even if updates made after TemporaryFailure succeed you must still call
136 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
139 /// Note that the update being processed here will not be replayed for you when you call
140 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
141 /// with the persisted ChannelMonitor on your own local disk prior to returning a
142 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
143 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
146 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
147 /// remote location (with local copies persisted immediately), it is anticipated that all
148 /// updates will return TemporaryFailure until the remote copies could be updated.
150 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
151 /// different watchtower and cannot update with all watchtowers that were previously informed
152 /// of this channel).
154 /// At reception of this error, ChannelManager will force-close the channel and return at
155 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
156 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
157 /// update must be rejected.
159 /// This failure may also signal a failure to update the local persisted copy of one of
160 /// the channel monitor instance.
162 /// Note that even when you fail a holder commitment transaction update, you must store the
163 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
164 /// broadcasts it (e.g distributed channel-monitor deployment)
166 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
167 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
168 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
169 /// lagging behind on block processing.
173 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
174 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
175 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
177 /// Contains a developer-readable error message.
179 pub struct MonitorUpdateError(pub &'static str);
181 /// An event to be processed by the ChannelManager.
183 pub enum MonitorEvent {
184 /// A monitor event containing an HTLCUpdate.
185 HTLCEvent(HTLCUpdate),
187 /// A monitor event that the Channel's commitment transaction was broadcasted.
188 CommitmentTxBroadcasted(OutPoint),
191 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
192 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
193 /// preimage claim backward will lead to loss of funds.
195 /// [`chain::Watch`]: ../trait.Watch.html
196 #[derive(Clone, PartialEq)]
197 pub struct HTLCUpdate {
198 pub(crate) payment_hash: PaymentHash,
199 pub(crate) payment_preimage: Option<PaymentPreimage>,
200 pub(crate) source: HTLCSource
202 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
204 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
205 /// instead claiming it in its own individual transaction.
206 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
207 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
208 /// HTLC-Success transaction.
209 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
210 /// transaction confirmed (and we use it in a few more, equivalent, places).
211 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
212 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
213 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
214 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
215 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
216 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
217 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
218 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
219 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
220 /// accurate block height.
221 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
222 /// with at worst this delay, so we are not only using this value as a mercy for them but also
223 /// us as a safeguard to delay with enough time.
224 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
225 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
226 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
227 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
228 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
229 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
230 /// keeping bumping another claim tx to solve the outpoint.
231 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
232 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
233 /// refuse to accept a new HTLC.
235 /// This is used for a few separate purposes:
236 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
237 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
239 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
240 /// condition with the above), we will fail this HTLC without telling the user we received it,
241 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
242 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
244 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
245 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
247 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
248 /// in a race condition between the user connecting a block (which would fail it) and the user
249 /// providing us the preimage (which would claim it).
251 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
252 /// end up force-closing the channel on us to claim it.
253 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
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 = "_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 unsigned_commitment_tx: Transaction, // TODO: We should actually only need the txid here
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 { ref unsigned_commitment_tx, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
532 unsigned_commitment_tx.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 unsigned_commitment_tx: 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.
620 pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
621 latest_update_id: u64,
622 commitment_transaction_number_obscure_factor: u64,
624 destination_script: Script,
625 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
626 counterparty_payment_script: Script,
627 shutdown_script: Script,
630 funding_info: (OutPoint, Script),
631 current_counterparty_commitment_txid: Option<Txid>,
632 prev_counterparty_commitment_txid: Option<Txid>,
634 counterparty_tx_cache: CounterpartyCommitmentTransaction,
635 funding_redeemscript: Script,
636 channel_value_satoshis: u64,
637 // first is the idx of the first of the two revocation points
638 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
640 on_holder_tx_csv: u16,
642 commitment_secrets: CounterpartyCommitmentSecrets,
643 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
644 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
645 /// Nor can we figure out their commitment numbers without the commitment transaction they are
646 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
647 /// commitment transactions which we find on-chain, mapping them to the commitment number which
648 /// can be used to derive the revocation key and claim the transactions.
649 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
650 /// Cache used to make pruning of payment_preimages faster.
651 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
652 /// counterparty transactions (ie should remain pretty small).
653 /// Serialized to disk but should generally not be sent to Watchtowers.
654 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
656 // We store two holder commitment transactions to avoid any race conditions where we may update
657 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
658 // various monitors for one channel being out of sync, and us broadcasting a holder
659 // transaction for which we have deleted claim information on some watchtowers.
660 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
661 current_holder_commitment_tx: HolderSignedTx,
663 // Used just for ChannelManager to make sure it has the latest channel data during
665 current_counterparty_commitment_number: u64,
666 // Used just for ChannelManager to make sure it has the latest channel data during
668 current_holder_commitment_number: u64,
670 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
672 pending_monitor_events: Vec<MonitorEvent>,
673 pending_events: Vec<Event>,
675 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
676 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
677 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
678 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
680 // If we get serialized out and re-read, we need to make sure that the chain monitoring
681 // interface knows about the TXOs that we want to be notified of spends of. We could probably
682 // be smart and derive them from the above storage fields, but its much simpler and more
683 // Obviously Correct (tm) if we just keep track of them explicitly.
684 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
687 pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
689 onchain_tx_handler: OnchainTxHandler<ChanSigner>,
691 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
692 // channel has been force-closed. After this is set, no further holder commitment transaction
693 // updates may occur, and we panic!() if one is provided.
694 lockdown_from_offchain: bool,
696 // Set once we've signed a holder commitment transaction and handed it over to our
697 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
698 // may occur, and we fail any such monitor updates.
700 // In case of update rejection due to a locally already signed commitment transaction, we
701 // nevertheless store update content to track in case of concurrent broadcast by another
702 // remote monitor out-of-order with regards to the block view.
703 holder_tx_signed: bool,
705 // We simply modify last_block_hash in Channel's block_connected so that serialization is
706 // consistent but hopefully the users' copy handles block_connected in a consistent way.
707 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
708 // their last_block_hash from its state and not based on updated copies that didn't run through
709 // the full block_connected).
710 last_block_hash: BlockHash,
711 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
714 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
715 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
716 /// underlying object
717 impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
718 fn eq(&self, other: &Self) -> bool {
719 if self.latest_update_id != other.latest_update_id ||
720 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
721 self.destination_script != other.destination_script ||
722 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
723 self.counterparty_payment_script != other.counterparty_payment_script ||
724 self.keys.pubkeys() != other.keys.pubkeys() ||
725 self.funding_info != other.funding_info ||
726 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
727 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
728 self.counterparty_tx_cache != other.counterparty_tx_cache ||
729 self.funding_redeemscript != other.funding_redeemscript ||
730 self.channel_value_satoshis != other.channel_value_satoshis ||
731 self.their_cur_revocation_points != other.their_cur_revocation_points ||
732 self.on_holder_tx_csv != other.on_holder_tx_csv ||
733 self.commitment_secrets != other.commitment_secrets ||
734 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
735 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
736 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
737 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
738 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
739 self.current_holder_commitment_number != other.current_holder_commitment_number ||
740 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
741 self.payment_preimages != other.payment_preimages ||
742 self.pending_monitor_events != other.pending_monitor_events ||
743 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
744 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
745 self.outputs_to_watch != other.outputs_to_watch ||
746 self.lockdown_from_offchain != other.lockdown_from_offchain ||
747 self.holder_tx_signed != other.holder_tx_signed
756 impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
757 /// Writes this monitor into the given writer, suitable for writing to disk.
759 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
760 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
761 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
762 /// returned block hash and the the current chain and then reconnecting blocks to get to the
763 /// best chain) upon deserializing the object!
764 pub fn serialize_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
765 //TODO: We still write out all the serialization here manually instead of using the fancy
766 //serialization framework we have, we should migrate things over to it.
767 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
768 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
770 self.latest_update_id.write(writer)?;
772 // Set in initial Channel-object creation, so should always be set by now:
773 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
775 self.destination_script.write(writer)?;
776 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
777 writer.write_all(&[0; 1])?;
778 broadcasted_holder_revokable_script.0.write(writer)?;
779 broadcasted_holder_revokable_script.1.write(writer)?;
780 broadcasted_holder_revokable_script.2.write(writer)?;
782 writer.write_all(&[1; 1])?;
785 self.counterparty_payment_script.write(writer)?;
786 self.shutdown_script.write(writer)?;
788 self.keys.write(writer)?;
789 writer.write_all(&self.funding_info.0.txid[..])?;
790 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
791 self.funding_info.1.write(writer)?;
792 self.current_counterparty_commitment_txid.write(writer)?;
793 self.prev_counterparty_commitment_txid.write(writer)?;
795 self.counterparty_tx_cache.write(writer)?;
796 self.funding_redeemscript.write(writer)?;
797 self.channel_value_satoshis.write(writer)?;
799 match self.their_cur_revocation_points {
800 Some((idx, pubkey, second_option)) => {
801 writer.write_all(&byte_utils::be48_to_array(idx))?;
802 writer.write_all(&pubkey.serialize())?;
803 match second_option {
804 Some(second_pubkey) => {
805 writer.write_all(&second_pubkey.serialize())?;
808 writer.write_all(&[0; 33])?;
813 writer.write_all(&byte_utils::be48_to_array(0))?;
817 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
819 self.commitment_secrets.write(writer)?;
821 macro_rules! serialize_htlc_in_commitment {
822 ($htlc_output: expr) => {
823 writer.write_all(&[$htlc_output.offered as u8; 1])?;
824 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
825 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
826 writer.write_all(&$htlc_output.payment_hash.0[..])?;
827 $htlc_output.transaction_output_index.write(writer)?;
831 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
832 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
833 writer.write_all(&txid[..])?;
834 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
835 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
836 serialize_htlc_in_commitment!(htlc_output);
837 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
841 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
842 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
843 writer.write_all(&txid[..])?;
844 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
847 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
848 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
849 writer.write_all(&payment_hash.0[..])?;
850 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
853 macro_rules! serialize_holder_tx {
854 ($holder_tx: expr) => {
855 $holder_tx.txid.write(writer)?;
856 writer.write_all(&$holder_tx.revocation_key.serialize())?;
857 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
858 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
859 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
860 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
862 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
863 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
864 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
865 serialize_htlc_in_commitment!(htlc_output);
866 if let &Some(ref their_sig) = sig {
868 writer.write_all(&their_sig.serialize_compact())?;
872 htlc_source.write(writer)?;
877 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
878 writer.write_all(&[1; 1])?;
879 serialize_holder_tx!(prev_holder_tx);
881 writer.write_all(&[0; 1])?;
884 serialize_holder_tx!(self.current_holder_commitment_tx);
886 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
887 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
889 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
890 for payment_preimage in self.payment_preimages.values() {
891 writer.write_all(&payment_preimage.0[..])?;
894 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
895 for event in self.pending_monitor_events.iter() {
897 MonitorEvent::HTLCEvent(upd) => {
901 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
905 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
906 for event in self.pending_events.iter() {
907 event.write(writer)?;
910 self.last_block_hash.write(writer)?;
912 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
913 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
914 writer.write_all(&byte_utils::be32_to_array(**target))?;
915 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
916 for ev in events.iter() {
918 OnchainEvent::HTLCUpdate { ref htlc_update } => {
920 htlc_update.0.write(writer)?;
921 htlc_update.1.write(writer)?;
923 OnchainEvent::MaturingOutput { ref descriptor } => {
925 descriptor.write(writer)?;
931 (self.outputs_to_watch.len() as u64).write(writer)?;
932 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
934 (idx_scripts.len() as u64).write(writer)?;
935 for (idx, script) in idx_scripts.iter() {
937 script.write(writer)?;
940 self.onchain_tx_handler.write(writer)?;
942 self.lockdown_from_offchain.write(writer)?;
943 self.holder_tx_signed.write(writer)?;
949 impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
950 pub(crate) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
951 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
952 counterparty_htlc_base_key: &PublicKey, counterparty_delayed_payment_base_key: &PublicKey,
953 on_holder_tx_csv: u16, funding_redeemscript: Script, channel_value_satoshis: u64,
954 commitment_transaction_number_obscure_factor: u64,
955 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
957 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
958 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
959 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
960 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
961 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
963 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key: *counterparty_delayed_payment_base_key, counterparty_htlc_base_key: *counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
965 let mut onchain_tx_handler = OnchainTxHandler::new(destination_script.clone(), keys.clone(), on_holder_tx_csv);
967 let holder_tx_sequence = initial_holder_commitment_tx.unsigned_tx.input[0].sequence as u64;
968 let holder_tx_locktime = initial_holder_commitment_tx.unsigned_tx.lock_time as u64;
969 let holder_commitment_tx = HolderSignedTx {
970 txid: initial_holder_commitment_tx.txid(),
971 revocation_key: initial_holder_commitment_tx.keys.revocation_key,
972 a_htlc_key: initial_holder_commitment_tx.keys.broadcaster_htlc_key,
973 b_htlc_key: initial_holder_commitment_tx.keys.countersignatory_htlc_key,
974 delayed_payment_key: initial_holder_commitment_tx.keys.broadcaster_delayed_payment_key,
975 per_commitment_point: initial_holder_commitment_tx.keys.per_commitment_point,
976 feerate_per_kw: initial_holder_commitment_tx.feerate_per_kw,
977 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
979 onchain_tx_handler.provide_latest_holder_tx(initial_holder_commitment_tx);
981 let mut outputs_to_watch = HashMap::new();
982 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
986 commitment_transaction_number_obscure_factor,
988 destination_script: destination_script.clone(),
989 broadcasted_holder_revokable_script: None,
990 counterparty_payment_script,
995 current_counterparty_commitment_txid: None,
996 prev_counterparty_commitment_txid: None,
998 counterparty_tx_cache,
999 funding_redeemscript,
1000 channel_value_satoshis,
1001 their_cur_revocation_points: None,
1005 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1006 counterparty_claimable_outpoints: HashMap::new(),
1007 counterparty_commitment_txn_on_chain: HashMap::new(),
1008 counterparty_hash_commitment_number: HashMap::new(),
1010 prev_holder_signed_commitment_tx: None,
1011 current_holder_commitment_tx: holder_commitment_tx,
1012 current_counterparty_commitment_number: 1 << 48,
1013 current_holder_commitment_number: 0xffff_ffff_ffff - ((((holder_tx_sequence & 0xffffff) << 3*8) | (holder_tx_locktime as u64 & 0xffffff)) ^ commitment_transaction_number_obscure_factor),
1015 payment_preimages: HashMap::new(),
1016 pending_monitor_events: Vec::new(),
1017 pending_events: Vec::new(),
1019 onchain_events_waiting_threshold_conf: HashMap::new(),
1024 lockdown_from_offchain: false,
1025 holder_tx_signed: false,
1027 last_block_hash: Default::default(),
1028 secp_ctx: Secp256k1::new(),
1032 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1033 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1034 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1035 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1036 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1037 return Err(MonitorUpdateError("Previous secret did not match new one"));
1040 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1041 // events for now-revoked/fulfilled HTLCs.
1042 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1043 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1048 if !self.payment_preimages.is_empty() {
1049 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1050 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1051 let min_idx = self.get_min_seen_secret();
1052 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1054 self.payment_preimages.retain(|&k, _| {
1055 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1056 if k == htlc.payment_hash {
1060 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1061 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1062 if k == htlc.payment_hash {
1067 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1074 counterparty_hash_commitment_number.remove(&k);
1083 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1084 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1085 /// possibly future revocation/preimage information) to claim outputs where possible.
1086 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1087 pub(crate) fn provide_latest_counterparty_commitment_tx_info<L: Deref>(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1088 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1089 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1090 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1092 for &(ref htlc, _) in &htlc_outputs {
1093 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1096 let new_txid = unsigned_commitment_tx.txid();
1097 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
1098 log_trace!(logger, "New potential counterparty commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
1099 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1100 self.current_counterparty_commitment_txid = Some(new_txid);
1101 self.counterparty_claimable_outpoints.insert(new_txid, htlc_outputs.clone());
1102 self.current_counterparty_commitment_number = commitment_number;
1103 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1104 match self.their_cur_revocation_points {
1105 Some(old_points) => {
1106 if old_points.0 == commitment_number + 1 {
1107 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1108 } else if old_points.0 == commitment_number + 2 {
1109 if let Some(old_second_point) = old_points.2 {
1110 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1112 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1115 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1119 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1122 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1123 for htlc in htlc_outputs {
1124 if htlc.0.transaction_output_index.is_some() {
1128 self.counterparty_tx_cache.per_htlc.insert(new_txid, htlcs);
1131 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1132 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1133 /// is important that any clones of this channel monitor (including remote clones) by kept
1134 /// up-to-date as our holder commitment transaction is updated.
1135 /// Panics if set_on_holder_tx_csv has never been called.
1136 fn provide_latest_holder_commitment_tx_info(&mut self, commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1137 let txid = commitment_tx.txid();
1138 let sequence = commitment_tx.unsigned_tx.input[0].sequence as u64;
1139 let locktime = commitment_tx.unsigned_tx.lock_time as u64;
1140 let mut new_holder_commitment_tx = HolderSignedTx {
1142 revocation_key: commitment_tx.keys.revocation_key,
1143 a_htlc_key: commitment_tx.keys.broadcaster_htlc_key,
1144 b_htlc_key: commitment_tx.keys.countersignatory_htlc_key,
1145 delayed_payment_key: commitment_tx.keys.broadcaster_delayed_payment_key,
1146 per_commitment_point: commitment_tx.keys.per_commitment_point,
1147 feerate_per_kw: commitment_tx.feerate_per_kw,
1150 self.onchain_tx_handler.provide_latest_holder_tx(commitment_tx);
1151 self.current_holder_commitment_number = 0xffff_ffff_ffff - ((((sequence & 0xffffff) << 3*8) | (locktime as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
1152 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1153 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1154 if self.holder_tx_signed {
1155 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1160 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1161 /// commitment_tx_infos which contain the payment hash have been revoked.
1162 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)
1163 where B::Target: BroadcasterInterface,
1164 F::Target: FeeEstimator,
1167 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1170 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1171 where B::Target: BroadcasterInterface,
1174 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1175 broadcaster.broadcast_transaction(tx);
1177 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1180 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1183 /// panics if the given update is not the next update by update_id.
1184 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1185 where B::Target: BroadcasterInterface,
1186 F::Target: FeeEstimator,
1189 // ChannelMonitor updates may be applied after force close if we receive a
1190 // preimage for a broadcasted commitment transaction HTLC output that we'd
1191 // like to claim on-chain. If this is the case, we no longer have guaranteed
1192 // access to the monitor's update ID, so we use a sentinel value instead.
1193 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1194 match updates.updates[0] {
1195 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1196 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1198 assert_eq!(updates.updates.len(), 1);
1199 } else if self.latest_update_id + 1 != updates.update_id {
1200 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1202 for update in updates.updates.iter() {
1204 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1205 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1206 if self.lockdown_from_offchain { panic!(); }
1207 self.provide_latest_holder_commitment_tx_info(commitment_tx.clone(), htlc_outputs.clone())?
1209 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } => {
1210 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1211 self.provide_latest_counterparty_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1213 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1214 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1215 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1217 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1218 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1219 self.provide_secret(*idx, *secret)?
1221 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1222 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1223 self.lockdown_from_offchain = true;
1224 if *should_broadcast {
1225 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1227 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");
1232 self.latest_update_id = updates.update_id;
1236 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1238 pub fn get_latest_update_id(&self) -> u64 {
1239 self.latest_update_id
1242 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1243 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1247 /// Gets a list of txids, with their output scripts (in the order they appear in the
1248 /// transaction), which we must learn about spends of via block_connected().
1250 /// (C-not exported) because we have no HashMap bindings
1251 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1252 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1253 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1254 // its trivial to do, double-check that here.
1255 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1256 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1258 &self.outputs_to_watch
1261 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1262 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1264 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
1265 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1266 let mut ret = Vec::new();
1267 mem::swap(&mut ret, &mut self.pending_monitor_events);
1271 /// Gets the list of pending events which were generated by previous actions, clearing the list
1274 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1275 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1276 /// no internal locking in ChannelMonitors.
1277 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1278 let mut ret = Vec::new();
1279 mem::swap(&mut ret, &mut self.pending_events);
1283 /// Can only fail if idx is < get_min_seen_secret
1284 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1285 self.commitment_secrets.get_secret(idx)
1288 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1289 self.commitment_secrets.get_min_seen_secret()
1292 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1293 self.current_counterparty_commitment_number
1296 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1297 self.current_holder_commitment_number
1300 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1301 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1302 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1303 /// HTLC-Success/HTLC-Timeout transactions.
1304 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1305 /// revoked counterparty commitment tx
1306 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 {
1307 // Most secp and related errors trying to create keys means we have no hope of constructing
1308 // a spend transaction...so we return no transactions to broadcast
1309 let mut claimable_outpoints = Vec::new();
1310 let mut watch_outputs = Vec::new();
1312 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1313 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1315 macro_rules! ignore_error {
1316 ( $thing : expr ) => {
1319 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1324 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);
1325 if commitment_number >= self.get_min_seen_secret() {
1326 let secret = self.get_secret(commitment_number).unwrap();
1327 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1328 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1329 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
1330 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));
1332 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1333 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1335 // First, process non-htlc outputs (to_holder & to_counterparty)
1336 for (idx, outp) in tx.output.iter().enumerate() {
1337 if outp.script_pubkey == revokeable_p2wsh {
1338 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};
1339 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});
1343 // Then, try to find revoked htlc outputs
1344 if let Some(ref per_commitment_data) = per_commitment_option {
1345 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1346 if let Some(transaction_output_index) = htlc.transaction_output_index {
1347 if transaction_output_index as usize >= tx.output.len() ||
1348 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1349 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1351 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};
1352 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1357 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1358 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1359 // We're definitely a counterparty commitment transaction!
1360 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1361 for (idx, outp) in tx.output.iter().enumerate() {
1362 watch_outputs.push((idx as u32, outp.clone()));
1364 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1366 macro_rules! check_htlc_fails {
1367 ($txid: expr, $commitment_tx: expr) => {
1368 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1369 for &(ref htlc, ref source_option) in outpoints.iter() {
1370 if let &Some(ref source) = source_option {
1371 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1372 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1373 hash_map::Entry::Occupied(mut entry) => {
1374 let e = entry.get_mut();
1375 e.retain(|ref event| {
1377 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1378 return htlc_update.0 != **source
1383 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1385 hash_map::Entry::Vacant(entry) => {
1386 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1394 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1395 check_htlc_fails!(txid, "current");
1397 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1398 check_htlc_fails!(txid, "counterparty");
1400 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1402 } else if let Some(per_commitment_data) = per_commitment_option {
1403 // While this isn't useful yet, there is a potential race where if a counterparty
1404 // revokes a state at the same time as the commitment transaction for that state is
1405 // confirmed, and the watchtower receives the block before the user, the user could
1406 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1407 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1408 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1410 for (idx, outp) in tx.output.iter().enumerate() {
1411 watch_outputs.push((idx as u32, outp.clone()));
1413 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1415 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1417 macro_rules! check_htlc_fails {
1418 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1419 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1420 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1421 if let &Some(ref source) = source_option {
1422 // Check if the HTLC is present in the commitment transaction that was
1423 // broadcast, but not if it was below the dust limit, which we should
1424 // fail backwards immediately as there is no way for us to learn the
1425 // payment_preimage.
1426 // Note that if the dust limit were allowed to change between
1427 // commitment transactions we'd want to be check whether *any*
1428 // broadcastable commitment transaction has the HTLC in it, but it
1429 // cannot currently change after channel initialization, so we don't
1431 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1432 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1436 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);
1437 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1438 hash_map::Entry::Occupied(mut entry) => {
1439 let e = entry.get_mut();
1440 e.retain(|ref event| {
1442 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1443 return htlc_update.0 != **source
1448 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1450 hash_map::Entry::Vacant(entry) => {
1451 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1459 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1460 check_htlc_fails!(txid, "current", 'current_loop);
1462 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1463 check_htlc_fails!(txid, "previous", 'prev_loop);
1466 if let Some(revocation_points) = self.their_cur_revocation_points {
1467 let revocation_point_option =
1468 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1469 else if let Some(point) = revocation_points.2.as_ref() {
1470 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1472 if let Some(revocation_point) = revocation_point_option {
1473 self.counterparty_payment_script = {
1474 // Note that the Network here is ignored as we immediately drop the address for the
1475 // script_pubkey version
1476 let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
1477 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
1480 // Then, try to find htlc outputs
1481 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1482 if let Some(transaction_output_index) = htlc.transaction_output_index {
1483 if transaction_output_index as usize >= tx.output.len() ||
1484 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1485 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1487 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1488 let aggregable = if !htlc.offered { false } else { true };
1489 if preimage.is_some() || !htlc.offered {
1490 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() };
1491 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1498 (claimable_outpoints, (commitment_txid, watch_outputs))
1501 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1502 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 {
1503 let htlc_txid = tx.txid();
1504 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1505 return (Vec::new(), None)
1508 macro_rules! ignore_error {
1509 ( $thing : expr ) => {
1512 Err(_) => return (Vec::new(), None)
1517 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1518 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1519 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1521 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1522 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 };
1523 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 });
1524 let outputs = vec![(0, tx.output[0].clone())];
1525 (claimable_outpoints, Some((htlc_txid, outputs)))
1528 // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can
1529 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1530 // script so we can detect whether a holder transaction has been seen on-chain.
1531 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Option<(Script, PublicKey, PublicKey)>) {
1532 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1534 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1535 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1537 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1538 if let Some(transaction_output_index) = htlc.transaction_output_index {
1539 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1540 witness_data: InputMaterial::HolderHTLC {
1541 preimage: if !htlc.offered {
1542 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1543 Some(preimage.clone())
1545 // We can't build an HTLC-Success transaction without the preimage
1549 amount: htlc.amount_msat,
1554 (claim_requests, broadcasted_holder_revokable_script)
1557 // Returns holder HTLC outputs to watch and react to in case of spending.
1558 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1559 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1560 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1561 if let Some(transaction_output_index) = htlc.transaction_output_index {
1562 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1568 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1569 /// revoked using data in holder_claimable_outpoints.
1570 /// Should not be used if check_spend_revoked_transaction succeeds.
1571 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 {
1572 let commitment_txid = tx.txid();
1573 let mut claim_requests = Vec::new();
1574 let mut watch_outputs = Vec::new();
1576 macro_rules! wait_threshold_conf {
1577 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1578 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1579 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1580 hash_map::Entry::Occupied(mut entry) => {
1581 let e = entry.get_mut();
1582 e.retain(|ref event| {
1584 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1585 return htlc_update.0 != $source
1590 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1592 hash_map::Entry::Vacant(entry) => {
1593 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1599 macro_rules! append_onchain_update {
1600 ($updates: expr, $to_watch: expr) => {
1601 claim_requests = $updates.0;
1602 self.broadcasted_holder_revokable_script = $updates.1;
1603 watch_outputs.append(&mut $to_watch);
1607 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1608 let mut is_holder_tx = false;
1610 if self.current_holder_commitment_tx.txid == commitment_txid {
1611 is_holder_tx = true;
1612 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1613 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1614 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1615 append_onchain_update!(res, to_watch);
1616 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1617 if holder_tx.txid == commitment_txid {
1618 is_holder_tx = true;
1619 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1620 let res = self.get_broadcasted_holder_claims(holder_tx);
1621 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1622 append_onchain_update!(res, to_watch);
1626 macro_rules! fail_dust_htlcs_after_threshold_conf {
1627 ($holder_tx: expr) => {
1628 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1629 if htlc.transaction_output_index.is_none() {
1630 if let &Some(ref source) = source {
1631 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1639 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1640 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1641 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1645 (claim_requests, (commitment_txid, watch_outputs))
1648 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1649 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1650 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1651 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1652 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1653 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1654 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1655 /// out-of-band the other node operator to coordinate with him if option is available to you.
1656 /// In any-case, choice is up to the user.
1657 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1658 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1659 self.holder_tx_signed = true;
1660 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1661 let txid = commitment_tx.txid();
1662 let mut res = vec![commitment_tx];
1663 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1664 if let Some(vout) = htlc.0.transaction_output_index {
1665 let preimage = if !htlc.0.offered {
1666 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1667 // We can't build an HTLC-Success transaction without the preimage
1671 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1672 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1677 // 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.
1678 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1684 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1685 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1686 /// revoked commitment transaction.
1687 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1688 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1689 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1690 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript) {
1691 let txid = commitment_tx.txid();
1692 let mut res = vec![commitment_tx];
1693 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1694 if let Some(vout) = htlc.0.transaction_output_index {
1695 let preimage = if !htlc.0.offered {
1696 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1697 // We can't build an HTLC-Success transaction without the preimage
1701 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1702 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1712 /// Processes transactions in a newly connected block, which may result in any of the following:
1713 /// - update the monitor's state against resolved HTLCs
1714 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1715 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1716 /// - detect settled outputs for later spending
1717 /// - schedule and bump any in-flight claims
1719 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1720 /// [`get_outputs_to_watch`].
1722 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1723 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)>)>
1724 where B::Target: BroadcasterInterface,
1725 F::Target: FeeEstimator,
1728 let txn_matched = self.filter_block(txdata);
1729 for tx in &txn_matched {
1730 let mut output_val = 0;
1731 for out in tx.output.iter() {
1732 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1733 output_val += out.value;
1734 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1738 let block_hash = header.block_hash();
1739 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1741 let mut watch_outputs = Vec::new();
1742 let mut claimable_outpoints = Vec::new();
1743 for tx in &txn_matched {
1744 if tx.input.len() == 1 {
1745 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1746 // commitment transactions and HTLC transactions will all only ever have one input,
1747 // which is an easy way to filter out any potential non-matching txn for lazy
1749 let prevout = &tx.input[0].previous_output;
1750 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1751 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1752 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1753 if !new_outputs.1.is_empty() {
1754 watch_outputs.push(new_outputs);
1756 if new_outpoints.is_empty() {
1757 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1758 if !new_outputs.1.is_empty() {
1759 watch_outputs.push(new_outputs);
1761 claimable_outpoints.append(&mut new_outpoints);
1763 claimable_outpoints.append(&mut new_outpoints);
1766 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1767 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1768 claimable_outpoints.append(&mut new_outpoints);
1769 if let Some(new_outputs) = new_outputs_option {
1770 watch_outputs.push(new_outputs);
1775 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1776 // can also be resolved in a few other ways which can have more than one output. Thus,
1777 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1778 self.is_resolving_htlc_output(&tx, height, &logger);
1780 self.is_paying_spendable_output(&tx, height, &logger);
1782 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1783 if should_broadcast {
1784 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() }});
1786 if should_broadcast {
1787 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1788 if let Some(commitment_tx) = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript) {
1789 self.holder_tx_signed = true;
1790 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1791 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
1792 if !new_outputs.is_empty() {
1793 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
1795 claimable_outpoints.append(&mut new_outpoints);
1798 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1801 OnchainEvent::HTLCUpdate { htlc_update } => {
1802 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1803 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1804 payment_hash: htlc_update.1,
1805 payment_preimage: None,
1806 source: htlc_update.0,
1809 OnchainEvent::MaturingOutput { descriptor } => {
1810 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1811 self.pending_events.push(Event::SpendableOutputs {
1812 outputs: vec![descriptor]
1819 self.onchain_tx_handler.block_connected(&txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
1820 self.last_block_hash = block_hash;
1822 // Determine new outputs to watch by comparing against previously known outputs to watch,
1823 // updating the latter in the process.
1824 watch_outputs.retain(|&(ref txid, ref txouts)| {
1825 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
1826 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
1830 // If we see a transaction for which we registered outputs previously,
1831 // make sure the registered scriptpubkey at the expected index match
1832 // the actual transaction output one. We failed this case before #653.
1833 for tx in &txn_matched {
1834 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
1835 for idx_and_script in outputs.iter() {
1836 assert!((idx_and_script.0 as usize) < tx.output.len());
1837 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
1845 /// Determines if the disconnected block contained any transactions of interest and updates
1847 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
1848 where B::Target: BroadcasterInterface,
1849 F::Target: FeeEstimator,
1852 let block_hash = header.block_hash();
1853 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1855 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1857 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1858 //- maturing spendable output has transaction paying us has been disconnected
1861 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1863 self.last_block_hash = block_hash;
1866 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
1867 /// transactions thereof.
1868 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
1869 let mut matched_txn = HashSet::new();
1870 txdata.iter().filter(|&&(_, tx)| {
1871 let mut matches = self.spends_watched_output(tx);
1872 for input in tx.input.iter() {
1873 if matches { break; }
1874 if matched_txn.contains(&input.previous_output.txid) {
1879 matched_txn.insert(tx.txid());
1882 }).map(|(_, tx)| *tx).collect()
1885 /// Checks if a given transaction spends any watched outputs.
1886 fn spends_watched_output(&self, tx: &Transaction) -> bool {
1887 for input in tx.input.iter() {
1888 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
1889 for (idx, _script_pubkey) in outputs.iter() {
1890 if *idx == input.previous_output.vout {
1893 // If the expected script is a known type, check that the witness
1894 // appears to be spending the correct type (ie that the match would
1895 // actually succeed in BIP 158/159-style filters).
1896 if _script_pubkey.is_v0_p2wsh() {
1897 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
1898 } else if _script_pubkey.is_v0_p2wpkh() {
1899 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
1900 } else { panic!(); }
1911 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
1912 // We need to consider all HTLCs which are:
1913 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
1914 // transactions and we'd end up in a race, or
1915 // * are in our latest holder commitment transaction, as this is the thing we will
1916 // broadcast if we go on-chain.
1917 // Note that we consider HTLCs which were below dust threshold here - while they don't
1918 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1919 // to the source, and if we don't fail the channel we will have to ensure that the next
1920 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1921 // easier to just fail the channel as this case should be rare enough anyway.
1922 macro_rules! scan_commitment {
1923 ($htlcs: expr, $holder_tx: expr) => {
1924 for ref htlc in $htlcs {
1925 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1926 // chain with enough room to claim the HTLC without our counterparty being able to
1927 // time out the HTLC first.
1928 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1929 // concern is being able to claim the corresponding inbound HTLC (on another
1930 // channel) before it expires. In fact, we don't even really care if our
1931 // counterparty here claims such an outbound HTLC after it expired as long as we
1932 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
1933 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
1934 // we give ourselves a few blocks of headroom after expiration before going
1935 // on-chain for an expired HTLC.
1936 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
1937 // from us until we've reached the point where we go on-chain with the
1938 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
1939 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
1940 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
1941 // inbound_cltv == height + CLTV_CLAIM_BUFFER
1942 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
1943 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
1944 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
1945 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
1946 // The final, above, condition is checked for statically in channelmanager
1947 // with CHECK_CLTV_EXPIRY_SANITY_2.
1948 let htlc_outbound = $holder_tx == htlc.offered;
1949 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
1950 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
1951 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
1958 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
1960 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1961 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
1962 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1965 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1966 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
1967 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1974 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
1975 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
1976 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
1977 'outer_loop: for input in &tx.input {
1978 let mut payment_data = None;
1979 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
1980 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
1981 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
1982 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
1984 macro_rules! log_claim {
1985 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
1986 // We found the output in question, but aren't failing it backwards
1987 // as we have no corresponding source and no valid counterparty commitment txid
1988 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
1989 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
1990 let outbound_htlc = $holder_tx == $htlc.offered;
1991 if ($holder_tx && revocation_sig_claim) ||
1992 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
1993 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
1994 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
1995 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
1996 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
1998 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
1999 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2000 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2001 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2006 macro_rules! check_htlc_valid_counterparty {
2007 ($counterparty_txid: expr, $htlc_output: expr) => {
2008 if let Some(txid) = $counterparty_txid {
2009 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2010 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2011 if let &Some(ref source) = pending_source {
2012 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2013 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2022 macro_rules! scan_commitment {
2023 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2024 for (ref htlc_output, source_option) in $htlcs {
2025 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2026 if let Some(ref source) = source_option {
2027 log_claim!($tx_info, $holder_tx, htlc_output, true);
2028 // We have a resolution of an HTLC either from one of our latest
2029 // holder commitment transactions or an unrevoked counterparty commitment
2030 // transaction. This implies we either learned a preimage, the HTLC
2031 // has timed out, or we screwed up. In any case, we should now
2032 // resolve the source HTLC with the original sender.
2033 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2034 } else if !$holder_tx {
2035 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2036 if payment_data.is_none() {
2037 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2040 if payment_data.is_none() {
2041 log_claim!($tx_info, $holder_tx, htlc_output, false);
2042 continue 'outer_loop;
2049 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2050 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2051 "our latest holder commitment tx", true);
2053 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2054 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2055 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2056 "our previous holder commitment tx", true);
2059 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2060 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2061 "counterparty commitment tx", false);
2064 // Check that scan_commitment, above, decided there is some source worth relaying an
2065 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2066 if let Some((source, payment_hash)) = payment_data {
2067 let mut payment_preimage = PaymentPreimage([0; 32]);
2068 if accepted_preimage_claim {
2069 if !self.pending_monitor_events.iter().any(
2070 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2071 payment_preimage.0.copy_from_slice(&input.witness[3]);
2072 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2074 payment_preimage: Some(payment_preimage),
2078 } else if offered_preimage_claim {
2079 if !self.pending_monitor_events.iter().any(
2080 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2081 upd.source == source
2083 payment_preimage.0.copy_from_slice(&input.witness[1]);
2084 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2086 payment_preimage: Some(payment_preimage),
2091 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);
2092 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2093 hash_map::Entry::Occupied(mut entry) => {
2094 let e = entry.get_mut();
2095 e.retain(|ref event| {
2097 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2098 return htlc_update.0 != source
2103 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2105 hash_map::Entry::Vacant(entry) => {
2106 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2114 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2115 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2116 let mut spendable_output = None;
2117 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2118 if i > ::std::u16::MAX as usize {
2119 // While it is possible that an output exists on chain which is greater than the
2120 // 2^16th output in a given transaction, this is only possible if the output is not
2121 // in a lightning transaction and was instead placed there by some third party who
2122 // wishes to give us money for no reason.
2123 // Namely, any lightning transactions which we pre-sign will never have anywhere
2124 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2125 // scripts are not longer than one byte in length and because they are inherently
2126 // non-standard due to their size.
2127 // Thus, it is completely safe to ignore such outputs, and while it may result in
2128 // us ignoring non-lightning fund to us, that is only possible if someone fills
2129 // nearly a full block with garbage just to hit this case.
2132 if outp.script_pubkey == self.destination_script {
2133 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2134 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2135 output: outp.clone(),
2138 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2139 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2140 spendable_output = Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
2141 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2142 per_commitment_point: broadcasted_holder_revokable_script.1,
2143 to_self_delay: self.on_holder_tx_csv,
2144 output: outp.clone(),
2145 key_derivation_params: self.keys.key_derivation_params(),
2146 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2150 } else if self.counterparty_payment_script == outp.script_pubkey {
2151 spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
2152 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2153 output: outp.clone(),
2154 key_derivation_params: self.keys.key_derivation_params(),
2157 } else if outp.script_pubkey == self.shutdown_script {
2158 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2159 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2160 output: outp.clone(),
2164 if let Some(spendable_output) = spendable_output {
2165 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2166 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2167 hash_map::Entry::Occupied(mut entry) => {
2168 let e = entry.get_mut();
2169 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2171 hash_map::Entry::Vacant(entry) => {
2172 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2179 /// `Persist` defines behavior for persisting channel monitors: this could mean
2180 /// writing once to disk, and/or uploading to one or more backup services.
2182 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2183 /// to disk/backups. And, on every update, you **must** persist either the
2184 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2185 /// of situations such as revoking a transaction, then crashing before this
2186 /// revocation can be persisted, then unintentionally broadcasting a revoked
2187 /// transaction and losing money. This is a risk because previous channel states
2188 /// are toxic, so it's important that whatever channel state is persisted is
2189 /// kept up-to-date.
2190 pub trait Persist<Keys: ChannelKeys>: Send + Sync {
2191 /// Persist a new channel's data. The data can be stored any way you want, but
2192 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2193 /// it is up to you to maintain a correct mapping between the outpoint and the
2194 /// stored channel data). Note that you **must** persist every new monitor to
2195 /// disk. See the `Persist` trait documentation for more details.
2197 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2198 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2200 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2201 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2202 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
2204 /// Update one channel's data. The provided `ChannelMonitor` has already
2205 /// applied the given update.
2207 /// Note that on every update, you **must** persist either the
2208 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2209 /// the `Persist` trait documentation for more details.
2211 /// If an implementer chooses to persist the updates only, they need to make
2212 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2213 /// the set of channel monitors is given to the `ChannelManager`
2214 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2215 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2216 /// persisted, then there is no need to persist individual updates.
2218 /// Note that there could be a performance tradeoff between persisting complete
2219 /// channel monitors on every update vs. persisting only updates and applying
2220 /// them in batches. The size of each monitor grows `O(number of state updates)`
2221 /// whereas updates are small and `O(1)`.
2223 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2224 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2225 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2227 /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
2228 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2229 /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
2230 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2231 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
2234 const MAX_ALLOC_SIZE: usize = 64*1024;
2236 impl<ChanSigner: ChannelKeys + Readable> Readable for (BlockHash, ChannelMonitor<ChanSigner>) {
2237 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
2238 macro_rules! unwrap_obj {
2242 Err(_) => return Err(DecodeError::InvalidValue),
2247 let _ver: u8 = Readable::read(reader)?;
2248 let min_ver: u8 = Readable::read(reader)?;
2249 if min_ver > SERIALIZATION_VERSION {
2250 return Err(DecodeError::UnknownVersion);
2253 let latest_update_id: u64 = Readable::read(reader)?;
2254 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2256 let destination_script = Readable::read(reader)?;
2257 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2259 let revokable_address = Readable::read(reader)?;
2260 let per_commitment_point = Readable::read(reader)?;
2261 let revokable_script = Readable::read(reader)?;
2262 Some((revokable_address, per_commitment_point, revokable_script))
2265 _ => return Err(DecodeError::InvalidValue),
2267 let counterparty_payment_script = Readable::read(reader)?;
2268 let shutdown_script = Readable::read(reader)?;
2270 let keys = Readable::read(reader)?;
2271 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2272 // barely-init'd ChannelMonitors that we can't do anything with.
2273 let outpoint = OutPoint {
2274 txid: Readable::read(reader)?,
2275 index: Readable::read(reader)?,
2277 let funding_info = (outpoint, Readable::read(reader)?);
2278 let current_counterparty_commitment_txid = Readable::read(reader)?;
2279 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2281 let counterparty_tx_cache = Readable::read(reader)?;
2282 let funding_redeemscript = Readable::read(reader)?;
2283 let channel_value_satoshis = Readable::read(reader)?;
2285 let their_cur_revocation_points = {
2286 let first_idx = <U48 as Readable>::read(reader)?.0;
2290 let first_point = Readable::read(reader)?;
2291 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2292 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2293 Some((first_idx, first_point, None))
2295 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2300 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2302 let commitment_secrets = Readable::read(reader)?;
2304 macro_rules! read_htlc_in_commitment {
2307 let offered: bool = Readable::read(reader)?;
2308 let amount_msat: u64 = Readable::read(reader)?;
2309 let cltv_expiry: u32 = Readable::read(reader)?;
2310 let payment_hash: PaymentHash = Readable::read(reader)?;
2311 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2313 HTLCOutputInCommitment {
2314 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2320 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2321 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2322 for _ in 0..counterparty_claimable_outpoints_len {
2323 let txid: Txid = Readable::read(reader)?;
2324 let htlcs_count: u64 = Readable::read(reader)?;
2325 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2326 for _ in 0..htlcs_count {
2327 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2329 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2330 return Err(DecodeError::InvalidValue);
2334 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2335 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2336 for _ in 0..counterparty_commitment_txn_on_chain_len {
2337 let txid: Txid = Readable::read(reader)?;
2338 let commitment_number = <U48 as Readable>::read(reader)?.0;
2339 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2340 return Err(DecodeError::InvalidValue);
2344 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2345 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2346 for _ in 0..counterparty_hash_commitment_number_len {
2347 let payment_hash: PaymentHash = Readable::read(reader)?;
2348 let commitment_number = <U48 as Readable>::read(reader)?.0;
2349 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2350 return Err(DecodeError::InvalidValue);
2354 macro_rules! read_holder_tx {
2357 let txid = Readable::read(reader)?;
2358 let revocation_key = Readable::read(reader)?;
2359 let a_htlc_key = Readable::read(reader)?;
2360 let b_htlc_key = Readable::read(reader)?;
2361 let delayed_payment_key = Readable::read(reader)?;
2362 let per_commitment_point = Readable::read(reader)?;
2363 let feerate_per_kw: u32 = Readable::read(reader)?;
2365 let htlcs_len: u64 = Readable::read(reader)?;
2366 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2367 for _ in 0..htlcs_len {
2368 let htlc = read_htlc_in_commitment!();
2369 let sigs = match <u8 as Readable>::read(reader)? {
2371 1 => Some(Readable::read(reader)?),
2372 _ => return Err(DecodeError::InvalidValue),
2374 htlcs.push((htlc, sigs, Readable::read(reader)?));
2379 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2386 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2389 Some(read_holder_tx!())
2391 _ => return Err(DecodeError::InvalidValue),
2393 let current_holder_commitment_tx = read_holder_tx!();
2395 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2396 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2398 let payment_preimages_len: u64 = Readable::read(reader)?;
2399 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2400 for _ in 0..payment_preimages_len {
2401 let preimage: PaymentPreimage = Readable::read(reader)?;
2402 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2403 if let Some(_) = payment_preimages.insert(hash, preimage) {
2404 return Err(DecodeError::InvalidValue);
2408 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2409 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2410 for _ in 0..pending_monitor_events_len {
2411 let ev = match <u8 as Readable>::read(reader)? {
2412 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2413 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2414 _ => return Err(DecodeError::InvalidValue)
2416 pending_monitor_events.push(ev);
2419 let pending_events_len: u64 = Readable::read(reader)?;
2420 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2421 for _ in 0..pending_events_len {
2422 if let Some(event) = MaybeReadable::read(reader)? {
2423 pending_events.push(event);
2427 let last_block_hash: BlockHash = Readable::read(reader)?;
2429 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2430 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2431 for _ in 0..waiting_threshold_conf_len {
2432 let height_target = Readable::read(reader)?;
2433 let events_len: u64 = Readable::read(reader)?;
2434 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2435 for _ in 0..events_len {
2436 let ev = match <u8 as Readable>::read(reader)? {
2438 let htlc_source = Readable::read(reader)?;
2439 let hash = Readable::read(reader)?;
2440 OnchainEvent::HTLCUpdate {
2441 htlc_update: (htlc_source, hash)
2445 let descriptor = Readable::read(reader)?;
2446 OnchainEvent::MaturingOutput {
2450 _ => return Err(DecodeError::InvalidValue),
2454 onchain_events_waiting_threshold_conf.insert(height_target, events);
2457 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2458 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>>())));
2459 for _ in 0..outputs_to_watch_len {
2460 let txid = Readable::read(reader)?;
2461 let outputs_len: u64 = Readable::read(reader)?;
2462 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2463 for _ in 0..outputs_len {
2464 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2466 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2467 return Err(DecodeError::InvalidValue);
2470 let onchain_tx_handler = Readable::read(reader)?;
2472 let lockdown_from_offchain = Readable::read(reader)?;
2473 let holder_tx_signed = Readable::read(reader)?;
2475 Ok((last_block_hash.clone(), ChannelMonitor {
2477 commitment_transaction_number_obscure_factor,
2480 broadcasted_holder_revokable_script,
2481 counterparty_payment_script,
2486 current_counterparty_commitment_txid,
2487 prev_counterparty_commitment_txid,
2489 counterparty_tx_cache,
2490 funding_redeemscript,
2491 channel_value_satoshis,
2492 their_cur_revocation_points,
2497 counterparty_claimable_outpoints,
2498 counterparty_commitment_txn_on_chain,
2499 counterparty_hash_commitment_number,
2501 prev_holder_signed_commitment_tx,
2502 current_holder_commitment_tx,
2503 current_counterparty_commitment_number,
2504 current_holder_commitment_number,
2507 pending_monitor_events,
2510 onchain_events_waiting_threshold_conf,
2515 lockdown_from_offchain,
2519 secp_ctx: Secp256k1::new(),
2526 use bitcoin::blockdata::script::{Script, Builder};
2527 use bitcoin::blockdata::opcodes;
2528 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2529 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2530 use bitcoin::util::bip143;
2531 use bitcoin::hashes::Hash;
2532 use bitcoin::hashes::sha256::Hash as Sha256;
2533 use bitcoin::hashes::hex::FromHex;
2534 use bitcoin::hash_types::Txid;
2536 use chain::channelmonitor::ChannelMonitor;
2537 use chain::transaction::OutPoint;
2538 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2539 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2541 use ln::chan_utils::{HTLCOutputInCommitment, HolderCommitmentTransaction};
2542 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2543 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2544 use bitcoin::secp256k1::Secp256k1;
2545 use std::sync::{Arc, Mutex};
2546 use chain::keysinterface::InMemoryChannelKeys;
2549 fn test_prune_preimages() {
2550 let secp_ctx = Secp256k1::new();
2551 let logger = Arc::new(TestLogger::new());
2552 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
2553 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
2555 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2556 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2558 let mut preimages = Vec::new();
2561 let preimage = PaymentPreimage([i; 32]);
2562 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2563 preimages.push((preimage, hash));
2567 macro_rules! preimages_slice_to_htlc_outputs {
2568 ($preimages_slice: expr) => {
2570 let mut res = Vec::new();
2571 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2572 res.push((HTLCOutputInCommitment {
2576 payment_hash: preimage.1.clone(),
2577 transaction_output_index: Some(idx as u32),
2584 macro_rules! preimages_to_holder_htlcs {
2585 ($preimages_slice: expr) => {
2587 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2588 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2594 macro_rules! test_preimages_exist {
2595 ($preimages_slice: expr, $monitor: expr) => {
2596 for preimage in $preimages_slice {
2597 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2602 let keys = InMemoryChannelKeys::new(
2604 SecretKey::from_slice(&[41; 32]).unwrap(),
2605 SecretKey::from_slice(&[41; 32]).unwrap(),
2606 SecretKey::from_slice(&[41; 32]).unwrap(),
2607 SecretKey::from_slice(&[41; 32]).unwrap(),
2608 SecretKey::from_slice(&[41; 32]).unwrap(),
2614 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2616 let mut monitor = ChannelMonitor::new(keys,
2617 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2618 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2619 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2620 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2621 10, Script::new(), 46, 0, HolderCommitmentTransaction::dummy());
2623 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2624 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2625 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2626 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2627 monitor.provide_latest_counterparty_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2628 for &(ref preimage, ref hash) in preimages.iter() {
2629 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2632 // Now provide a secret, pruning preimages 10-15
2633 let mut secret = [0; 32];
2634 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2635 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2636 assert_eq!(monitor.payment_preimages.len(), 15);
2637 test_preimages_exist!(&preimages[0..10], monitor);
2638 test_preimages_exist!(&preimages[15..20], monitor);
2640 // Now provide a further secret, pruning preimages 15-17
2641 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2642 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2643 assert_eq!(monitor.payment_preimages.len(), 13);
2644 test_preimages_exist!(&preimages[0..10], monitor);
2645 test_preimages_exist!(&preimages[17..20], monitor);
2647 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2648 // previous commitment tx's preimages too
2649 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2650 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2651 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2652 assert_eq!(monitor.payment_preimages.len(), 12);
2653 test_preimages_exist!(&preimages[0..10], monitor);
2654 test_preimages_exist!(&preimages[18..20], monitor);
2656 // But if we do it again, we'll prune 5-10
2657 monitor.provide_latest_holder_commitment_tx_info(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2658 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2659 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2660 assert_eq!(monitor.payment_preimages.len(), 5);
2661 test_preimages_exist!(&preimages[0..5], monitor);
2665 fn test_claim_txn_weight_computation() {
2666 // We test Claim txn weight, knowing that we want expected weigth and
2667 // not actual case to avoid sigs and time-lock delays hell variances.
2669 let secp_ctx = Secp256k1::new();
2670 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2671 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2672 let mut sum_actual_sigs = 0;
2674 macro_rules! sign_input {
2675 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2676 let htlc = HTLCOutputInCommitment {
2677 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2679 cltv_expiry: 2 << 16,
2680 payment_hash: PaymentHash([1; 32]),
2681 transaction_output_index: Some($idx as u32),
2683 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2684 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2685 let sig = secp_ctx.sign(&sighash, &privkey);
2686 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2687 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2688 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2689 if *$input_type == InputDescriptors::RevokedOutput {
2690 $sighash_parts.access_witness($idx).push(vec!(1));
2691 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2692 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2693 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2694 $sighash_parts.access_witness($idx).push(vec![0]);
2696 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2698 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2699 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2700 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2701 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2705 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2706 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2708 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2709 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2711 claim_tx.input.push(TxIn {
2712 previous_output: BitcoinOutPoint {
2716 script_sig: Script::new(),
2717 sequence: 0xfffffffd,
2718 witness: Vec::new(),
2721 claim_tx.output.push(TxOut {
2722 script_pubkey: script_pubkey.clone(),
2725 let base_weight = claim_tx.get_weight();
2726 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2728 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2729 for (idx, inp) in inputs_des.iter().enumerate() {
2730 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2733 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));
2735 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2736 claim_tx.input.clear();
2737 sum_actual_sigs = 0;
2739 claim_tx.input.push(TxIn {
2740 previous_output: BitcoinOutPoint {
2744 script_sig: Script::new(),
2745 sequence: 0xfffffffd,
2746 witness: Vec::new(),
2749 let base_weight = claim_tx.get_weight();
2750 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2752 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2753 for (idx, inp) in inputs_des.iter().enumerate() {
2754 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2757 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));
2759 // Justice tx with 1 revoked HTLC-Success tx output
2760 claim_tx.input.clear();
2761 sum_actual_sigs = 0;
2762 claim_tx.input.push(TxIn {
2763 previous_output: BitcoinOutPoint {
2767 script_sig: Script::new(),
2768 sequence: 0xfffffffd,
2769 witness: Vec::new(),
2771 let base_weight = claim_tx.get_weight();
2772 let inputs_des = vec![InputDescriptors::RevokedOutput];
2774 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2775 for (idx, inp) in inputs_des.iter().enumerate() {
2776 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2779 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));
2782 // Further testing is done in the ChannelManager integration tests.