1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
23 //! [`chain::Watch`]: ../trait.Watch.html
25 use bitcoin::blockdata::block::{Block, BlockHeader};
26 use bitcoin::blockdata::transaction::{TxOut,Transaction};
27 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
28 use bitcoin::blockdata::script::{Script, Builder};
29 use bitcoin::blockdata::opcodes;
31 use bitcoin::hashes::Hash;
32 use bitcoin::hashes::sha256::Hash as Sha256;
33 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
35 use bitcoin::secp256k1::{Secp256k1,Signature};
36 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
37 use bitcoin::secp256k1;
39 use ln::msgs::DecodeError;
41 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
42 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
43 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
45 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
46 use chain::transaction::{OutPoint, TransactionData};
47 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
48 use util::logger::Logger;
49 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
51 use util::events::Event;
53 use std::cell::RefCell;
54 use std::collections::{HashMap, HashSet, hash_map};
56 use std::ops::{Deref, DerefMut};
59 /// An update generated by the underlying Channel itself which contains some new information the
60 /// ChannelMonitor should be made aware of.
61 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
64 pub struct ChannelMonitorUpdate {
65 pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
66 /// The sequence number of this update. Updates *must* be replayed in-order according to this
67 /// sequence number (and updates may panic if they are not). The update_id values are strictly
68 /// increasing and increase by one for each new update, with one exception specified below.
70 /// This sequence number is also used to track up to which points updates which returned
71 /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
72 /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
74 /// The only instance where update_id values are not strictly increasing is the case where we
75 /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
76 /// its docs for more details.
78 /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
83 /// (1) a channel has been force closed and
84 /// (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
85 /// this channel's (the backward link's) broadcasted commitment transaction
86 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
87 /// with the update providing said payment preimage. No other update types are allowed after
89 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
91 impl Writeable for ChannelMonitorUpdate {
92 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
93 self.update_id.write(w)?;
94 (self.updates.len() as u64).write(w)?;
95 for update_step in self.updates.iter() {
96 update_step.write(w)?;
101 impl Readable for ChannelMonitorUpdate {
102 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
103 let update_id: u64 = Readable::read(r)?;
104 let len: u64 = Readable::read(r)?;
105 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
107 updates.push(Readable::read(r)?);
109 Ok(Self { update_id, updates })
113 /// An error enum representing a failure to persist a channel monitor update.
114 #[derive(Clone, Debug)]
115 pub enum ChannelMonitorUpdateErr {
116 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
117 /// our state failed, but is expected to succeed at some point in the future).
119 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
120 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
121 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
122 /// restore the channel to an operational state.
124 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
125 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
126 /// writing out the latest ChannelManager state.
128 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
129 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
130 /// to claim it on this channel) and those updates must be applied wherever they can be. At
131 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
132 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
133 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
136 /// Note that even if updates made after TemporaryFailure succeed you must still call
137 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
140 /// Note that the update being processed here will not be replayed for you when you call
141 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
142 /// with the persisted ChannelMonitor on your own local disk prior to returning a
143 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
144 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
147 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
148 /// remote location (with local copies persisted immediately), it is anticipated that all
149 /// updates will return TemporaryFailure until the remote copies could be updated.
151 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
152 /// different watchtower and cannot update with all watchtowers that were previously informed
153 /// of this channel).
155 /// At reception of this error, ChannelManager will force-close the channel and return at
156 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
157 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
158 /// update must be rejected.
160 /// This failure may also signal a failure to update the local persisted copy of one of
161 /// the channel monitor instance.
163 /// Note that even when you fail a holder commitment transaction update, you must store the
164 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
165 /// broadcasts it (e.g distributed channel-monitor deployment)
167 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
168 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
169 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
170 /// lagging behind on block processing.
174 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
175 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
176 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
178 /// Contains a developer-readable error message.
179 #[derive(Clone, Debug)]
180 pub struct MonitorUpdateError(pub &'static str);
182 /// An event to be processed by the ChannelManager.
183 #[derive(Clone, PartialEq)]
184 pub enum MonitorEvent {
185 /// A monitor event containing an HTLCUpdate.
186 HTLCEvent(HTLCUpdate),
188 /// A monitor event that the Channel's commitment transaction was broadcasted.
189 CommitmentTxBroadcasted(OutPoint),
192 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
193 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
194 /// preimage claim backward will lead to loss of funds.
196 /// [`chain::Watch`]: ../trait.Watch.html
197 #[derive(Clone, PartialEq)]
198 pub struct HTLCUpdate {
199 pub(crate) payment_hash: PaymentHash,
200 pub(crate) payment_preimage: Option<PaymentPreimage>,
201 pub(crate) source: HTLCSource
203 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
205 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
206 /// instead claiming it in its own individual transaction.
207 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
208 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
209 /// HTLC-Success transaction.
210 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
211 /// transaction confirmed (and we use it in a few more, equivalent, places).
212 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
213 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
214 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
215 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
216 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
217 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
218 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
219 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
220 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
221 /// accurate block height.
222 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
223 /// with at worst this delay, so we are not only using this value as a mercy for them but also
224 /// us as a safeguard to delay with enough time.
225 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
226 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
227 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
228 /// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
229 /// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
230 /// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
231 /// keeping bumping another claim tx to solve the outpoint.
232 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
233 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
234 /// refuse to accept a new HTLC.
236 /// This is used for a few separate purposes:
237 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
238 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
240 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
241 /// condition with the above), we will fail this HTLC without telling the user we received it,
242 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
243 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
245 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
246 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
248 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
249 /// in a race condition between the user connecting a block (which would fail it) and the user
250 /// providing us the preimage (which would claim it).
252 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
253 /// end up force-closing the channel on us to claim it.
254 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
256 // TODO(devrandom) replace this with HolderCommitmentTransaction
257 #[derive(Clone, PartialEq)]
258 struct HolderSignedTx {
259 /// txid of the transaction in tx, just used to make comparison faster
261 revocation_key: PublicKey,
262 a_htlc_key: PublicKey,
263 b_htlc_key: PublicKey,
264 delayed_payment_key: PublicKey,
265 per_commitment_point: PublicKey,
267 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
270 /// We use this to track counterparty commitment transactions and htlcs outputs and
271 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
273 struct CounterpartyCommitmentTransaction {
274 counterparty_delayed_payment_base_key: PublicKey,
275 counterparty_htlc_base_key: PublicKey,
276 on_counterparty_tx_csv: u16,
277 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
280 impl Writeable for CounterpartyCommitmentTransaction {
281 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
282 self.counterparty_delayed_payment_base_key.write(w)?;
283 self.counterparty_htlc_base_key.write(w)?;
284 w.write_all(&byte_utils::be16_to_array(self.on_counterparty_tx_csv))?;
285 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
286 for (ref txid, ref htlcs) in self.per_htlc.iter() {
287 w.write_all(&txid[..])?;
288 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
289 for &ref htlc in htlcs.iter() {
296 impl Readable for CounterpartyCommitmentTransaction {
297 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
298 let counterparty_commitment_transaction = {
299 let counterparty_delayed_payment_base_key = Readable::read(r)?;
300 let counterparty_htlc_base_key = Readable::read(r)?;
301 let on_counterparty_tx_csv: u16 = Readable::read(r)?;
302 let per_htlc_len: u64 = Readable::read(r)?;
303 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
304 for _ in 0..per_htlc_len {
305 let txid: Txid = Readable::read(r)?;
306 let htlcs_count: u64 = Readable::read(r)?;
307 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
308 for _ in 0..htlcs_count {
309 let htlc = Readable::read(r)?;
312 if let Some(_) = per_htlc.insert(txid, htlcs) {
313 return Err(DecodeError::InvalidValue);
316 CounterpartyCommitmentTransaction {
317 counterparty_delayed_payment_base_key,
318 counterparty_htlc_base_key,
319 on_counterparty_tx_csv,
323 Ok(counterparty_commitment_transaction)
327 /// When ChannelMonitor discovers an onchain outpoint being a step of a channel and that it needs
328 /// to generate a tx to push channel state forward, we cache outpoint-solving tx material to build
329 /// a new bumped one in case of lenghty confirmation delay
330 #[derive(Clone, PartialEq)]
331 pub(crate) enum InputMaterial {
333 per_commitment_point: PublicKey,
334 counterparty_delayed_payment_base_key: PublicKey,
335 counterparty_htlc_base_key: PublicKey,
336 per_commitment_key: SecretKey,
337 input_descriptor: InputDescriptors,
339 htlc: Option<HTLCOutputInCommitment>,
340 on_counterparty_tx_csv: u16,
343 per_commitment_point: PublicKey,
344 counterparty_delayed_payment_base_key: PublicKey,
345 counterparty_htlc_base_key: PublicKey,
346 preimage: Option<PaymentPreimage>,
347 htlc: HTLCOutputInCommitment
350 preimage: Option<PaymentPreimage>,
354 funding_redeemscript: Script,
358 impl Writeable for InputMaterial {
359 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
361 &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv} => {
362 writer.write_all(&[0; 1])?;
363 per_commitment_point.write(writer)?;
364 counterparty_delayed_payment_base_key.write(writer)?;
365 counterparty_htlc_base_key.write(writer)?;
366 writer.write_all(&per_commitment_key[..])?;
367 input_descriptor.write(writer)?;
368 writer.write_all(&byte_utils::be64_to_array(*amount))?;
370 on_counterparty_tx_csv.write(writer)?;
372 &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc} => {
373 writer.write_all(&[1; 1])?;
374 per_commitment_point.write(writer)?;
375 counterparty_delayed_payment_base_key.write(writer)?;
376 counterparty_htlc_base_key.write(writer)?;
377 preimage.write(writer)?;
380 &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
381 writer.write_all(&[2; 1])?;
382 preimage.write(writer)?;
383 writer.write_all(&byte_utils::be64_to_array(*amount))?;
385 &InputMaterial::Funding { ref funding_redeemscript } => {
386 writer.write_all(&[3; 1])?;
387 funding_redeemscript.write(writer)?;
394 impl Readable for InputMaterial {
395 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
396 let input_material = match <u8 as Readable>::read(reader)? {
398 let per_commitment_point = Readable::read(reader)?;
399 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
400 let counterparty_htlc_base_key = Readable::read(reader)?;
401 let per_commitment_key = Readable::read(reader)?;
402 let input_descriptor = Readable::read(reader)?;
403 let amount = Readable::read(reader)?;
404 let htlc = Readable::read(reader)?;
405 let on_counterparty_tx_csv = Readable::read(reader)?;
406 InputMaterial::Revoked {
407 per_commitment_point,
408 counterparty_delayed_payment_base_key,
409 counterparty_htlc_base_key,
414 on_counterparty_tx_csv
418 let per_commitment_point = Readable::read(reader)?;
419 let counterparty_delayed_payment_base_key = Readable::read(reader)?;
420 let counterparty_htlc_base_key = Readable::read(reader)?;
421 let preimage = Readable::read(reader)?;
422 let htlc = Readable::read(reader)?;
423 InputMaterial::CounterpartyHTLC {
424 per_commitment_point,
425 counterparty_delayed_payment_base_key,
426 counterparty_htlc_base_key,
432 let preimage = Readable::read(reader)?;
433 let amount = Readable::read(reader)?;
434 InputMaterial::HolderHTLC {
440 InputMaterial::Funding {
441 funding_redeemscript: Readable::read(reader)?,
444 _ => return Err(DecodeError::InvalidValue),
450 /// ClaimRequest is a descriptor structure to communicate between detection
451 /// and reaction module. They are generated by ChannelMonitor while parsing
452 /// onchain txn leaked from a channel and handed over to OnchainTxHandler which
453 /// is responsible for opportunistic aggregation, selecting and enforcing
454 /// bumping logic, building and signing transactions.
455 pub(crate) struct ClaimRequest {
456 // Block height before which claiming is exclusive to one party,
457 // after reaching it, claiming may be contentious.
458 pub(crate) absolute_timelock: u32,
459 // Timeout tx must have nLocktime set which means aggregating multiple
460 // ones must take the higher nLocktime among them to satisfy all of them.
461 // Sadly it has few pitfalls, a) it takes longuer to get fund back b) CLTV_DELTA
462 // of a sooner-HTLC could be swallowed by the highest nLocktime of the HTLC set.
463 // Do simplify we mark them as non-aggregable.
464 pub(crate) aggregable: bool,
465 // Basic bitcoin outpoint (txid, vout)
466 pub(crate) outpoint: BitcoinOutPoint,
467 // Following outpoint type, set of data needed to generate transaction digest
468 // and satisfy witness program.
469 pub(crate) witness_data: InputMaterial
472 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
473 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
474 #[derive(Clone, PartialEq)]
476 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
477 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
478 /// only win from it, so it's never an OnchainEvent
480 htlc_update: (HTLCSource, PaymentHash),
483 descriptor: SpendableOutputDescriptor,
487 const SERIALIZATION_VERSION: u8 = 1;
488 const MIN_SERIALIZATION_VERSION: u8 = 1;
490 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
492 pub(crate) enum ChannelMonitorUpdateStep {
493 LatestHolderCommitmentTXInfo {
494 commitment_tx: HolderCommitmentTransaction,
495 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
497 LatestCounterpartyCommitmentTXInfo {
498 commitment_txid: Txid,
499 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
500 commitment_number: u64,
501 their_revocation_point: PublicKey,
504 payment_preimage: PaymentPreimage,
510 /// Used to indicate that the no future updates will occur, and likely that the latest holder
511 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
513 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
514 /// think we've fallen behind!
515 should_broadcast: bool,
519 impl Writeable for ChannelMonitorUpdateStep {
520 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
522 &ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { ref commitment_tx, ref htlc_outputs } => {
524 commitment_tx.write(w)?;
525 (htlc_outputs.len() as u64).write(w)?;
526 for &(ref output, ref signature, ref source) in htlc_outputs.iter() {
532 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, ref htlc_outputs, ref commitment_number, ref their_revocation_point } => {
534 commitment_txid.write(w)?;
535 commitment_number.write(w)?;
536 their_revocation_point.write(w)?;
537 (htlc_outputs.len() as u64).write(w)?;
538 for &(ref output, ref source) in htlc_outputs.iter() {
540 source.as_ref().map(|b| b.as_ref()).write(w)?;
543 &ChannelMonitorUpdateStep::PaymentPreimage { ref payment_preimage } => {
545 payment_preimage.write(w)?;
547 &ChannelMonitorUpdateStep::CommitmentSecret { ref idx, ref secret } => {
552 &ChannelMonitorUpdateStep::ChannelForceClosed { ref should_broadcast } => {
554 should_broadcast.write(w)?;
560 impl Readable for ChannelMonitorUpdateStep {
561 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
562 match Readable::read(r)? {
564 Ok(ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
565 commitment_tx: Readable::read(r)?,
567 let len: u64 = Readable::read(r)?;
568 let mut res = Vec::new();
570 res.push((Readable::read(r)?, Readable::read(r)?, Readable::read(r)?));
577 Ok(ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
578 commitment_txid: Readable::read(r)?,
579 commitment_number: Readable::read(r)?,
580 their_revocation_point: Readable::read(r)?,
582 let len: u64 = Readable::read(r)?;
583 let mut res = Vec::new();
585 res.push((Readable::read(r)?, <Option<HTLCSource> as Readable>::read(r)?.map(|o| Box::new(o))));
592 Ok(ChannelMonitorUpdateStep::PaymentPreimage {
593 payment_preimage: Readable::read(r)?,
597 Ok(ChannelMonitorUpdateStep::CommitmentSecret {
598 idx: Readable::read(r)?,
599 secret: Readable::read(r)?,
603 Ok(ChannelMonitorUpdateStep::ChannelForceClosed {
604 should_broadcast: Readable::read(r)?
607 _ => Err(DecodeError::InvalidValue),
612 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
613 /// on-chain transactions to ensure no loss of funds occurs.
615 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
616 /// information and are actively monitoring the chain.
618 /// Pending Events or updated HTLCs which have not yet been read out by
619 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
620 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
621 /// gotten are fully handled before re-serializing the new state.
623 /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
624 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
625 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
626 /// returned block hash and the the current chain and then reconnecting blocks to get to the
627 /// best chain) upon deserializing the object!
628 pub struct ChannelMonitor<Signer: Sign> {
629 latest_update_id: u64,
630 commitment_transaction_number_obscure_factor: u64,
632 destination_script: Script,
633 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
634 counterparty_payment_script: Script,
635 shutdown_script: Script,
637 channel_keys_id: [u8; 32],
638 holder_revocation_basepoint: PublicKey,
639 funding_info: (OutPoint, Script),
640 current_counterparty_commitment_txid: Option<Txid>,
641 prev_counterparty_commitment_txid: Option<Txid>,
643 counterparty_tx_cache: CounterpartyCommitmentTransaction,
644 funding_redeemscript: Script,
645 channel_value_satoshis: u64,
646 // first is the idx of the first of the two revocation points
647 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
649 on_holder_tx_csv: u16,
651 commitment_secrets: CounterpartyCommitmentSecrets,
652 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
653 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
654 /// Nor can we figure out their commitment numbers without the commitment transaction they are
655 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
656 /// commitment transactions which we find on-chain, mapping them to the commitment number which
657 /// can be used to derive the revocation key and claim the transactions.
658 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
659 /// Cache used to make pruning of payment_preimages faster.
660 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
661 /// counterparty transactions (ie should remain pretty small).
662 /// Serialized to disk but should generally not be sent to Watchtowers.
663 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
665 // We store two holder commitment transactions to avoid any race conditions where we may update
666 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
667 // various monitors for one channel being out of sync, and us broadcasting a holder
668 // transaction for which we have deleted claim information on some watchtowers.
669 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
670 current_holder_commitment_tx: HolderSignedTx,
672 // Used just for ChannelManager to make sure it has the latest channel data during
674 current_counterparty_commitment_number: u64,
675 // Used just for ChannelManager to make sure it has the latest channel data during
677 current_holder_commitment_number: u64,
679 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
681 pending_monitor_events: Vec<MonitorEvent>,
682 pending_events: Vec<Event>,
684 // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
685 // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
686 // actions when we receive a block with given height. Actions depend on OnchainEvent type.
687 onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
689 // If we get serialized out and re-read, we need to make sure that the chain monitoring
690 // interface knows about the TXOs that we want to be notified of spends of. We could probably
691 // be smart and derive them from the above storage fields, but its much simpler and more
692 // Obviously Correct (tm) if we just keep track of them explicitly.
693 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
696 pub onchain_tx_handler: OnchainTxHandler<Signer>,
698 onchain_tx_handler: OnchainTxHandler<Signer>,
700 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
701 // channel has been force-closed. After this is set, no further holder commitment transaction
702 // updates may occur, and we panic!() if one is provided.
703 lockdown_from_offchain: bool,
705 // Set once we've signed a holder commitment transaction and handed it over to our
706 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
707 // may occur, and we fail any such monitor updates.
709 // In case of update rejection due to a locally already signed commitment transaction, we
710 // nevertheless store update content to track in case of concurrent broadcast by another
711 // remote monitor out-of-order with regards to the block view.
712 holder_tx_signed: bool,
714 // We simply modify last_block_hash in Channel's block_connected so that serialization is
715 // consistent but hopefully the users' copy handles block_connected in a consistent way.
716 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
717 // their last_block_hash from its state and not based on updated copies that didn't run through
718 // the full block_connected).
719 last_block_hash: BlockHash,
720 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
723 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
724 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
725 /// underlying object
726 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
727 fn eq(&self, other: &Self) -> bool {
728 if self.latest_update_id != other.latest_update_id ||
729 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
730 self.destination_script != other.destination_script ||
731 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
732 self.counterparty_payment_script != other.counterparty_payment_script ||
733 self.channel_keys_id != other.channel_keys_id ||
734 self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
735 self.funding_info != other.funding_info ||
736 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
737 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
738 self.counterparty_tx_cache != other.counterparty_tx_cache ||
739 self.funding_redeemscript != other.funding_redeemscript ||
740 self.channel_value_satoshis != other.channel_value_satoshis ||
741 self.their_cur_revocation_points != other.their_cur_revocation_points ||
742 self.on_holder_tx_csv != other.on_holder_tx_csv ||
743 self.commitment_secrets != other.commitment_secrets ||
744 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
745 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
746 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
747 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
748 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
749 self.current_holder_commitment_number != other.current_holder_commitment_number ||
750 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
751 self.payment_preimages != other.payment_preimages ||
752 self.pending_monitor_events != other.pending_monitor_events ||
753 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
754 self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
755 self.outputs_to_watch != other.outputs_to_watch ||
756 self.lockdown_from_offchain != other.lockdown_from_offchain ||
757 self.holder_tx_signed != other.holder_tx_signed
766 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
767 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
768 //TODO: We still write out all the serialization here manually instead of using the fancy
769 //serialization framework we have, we should migrate things over to it.
770 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
771 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
773 self.latest_update_id.write(writer)?;
775 // Set in initial Channel-object creation, so should always be set by now:
776 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
778 self.destination_script.write(writer)?;
779 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
780 writer.write_all(&[0; 1])?;
781 broadcasted_holder_revokable_script.0.write(writer)?;
782 broadcasted_holder_revokable_script.1.write(writer)?;
783 broadcasted_holder_revokable_script.2.write(writer)?;
785 writer.write_all(&[1; 1])?;
788 self.counterparty_payment_script.write(writer)?;
789 self.shutdown_script.write(writer)?;
791 self.channel_keys_id.write(writer)?;
792 self.holder_revocation_basepoint.write(writer)?;
793 writer.write_all(&self.funding_info.0.txid[..])?;
794 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
795 self.funding_info.1.write(writer)?;
796 self.current_counterparty_commitment_txid.write(writer)?;
797 self.prev_counterparty_commitment_txid.write(writer)?;
799 self.counterparty_tx_cache.write(writer)?;
800 self.funding_redeemscript.write(writer)?;
801 self.channel_value_satoshis.write(writer)?;
803 match self.their_cur_revocation_points {
804 Some((idx, pubkey, second_option)) => {
805 writer.write_all(&byte_utils::be48_to_array(idx))?;
806 writer.write_all(&pubkey.serialize())?;
807 match second_option {
808 Some(second_pubkey) => {
809 writer.write_all(&second_pubkey.serialize())?;
812 writer.write_all(&[0; 33])?;
817 writer.write_all(&byte_utils::be48_to_array(0))?;
821 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
823 self.commitment_secrets.write(writer)?;
825 macro_rules! serialize_htlc_in_commitment {
826 ($htlc_output: expr) => {
827 writer.write_all(&[$htlc_output.offered as u8; 1])?;
828 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
829 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
830 writer.write_all(&$htlc_output.payment_hash.0[..])?;
831 $htlc_output.transaction_output_index.write(writer)?;
835 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
836 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
837 writer.write_all(&txid[..])?;
838 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
839 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
840 serialize_htlc_in_commitment!(htlc_output);
841 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
845 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
846 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
847 writer.write_all(&txid[..])?;
848 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
851 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
852 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
853 writer.write_all(&payment_hash.0[..])?;
854 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
857 macro_rules! serialize_holder_tx {
858 ($holder_tx: expr) => {
859 $holder_tx.txid.write(writer)?;
860 writer.write_all(&$holder_tx.revocation_key.serialize())?;
861 writer.write_all(&$holder_tx.a_htlc_key.serialize())?;
862 writer.write_all(&$holder_tx.b_htlc_key.serialize())?;
863 writer.write_all(&$holder_tx.delayed_payment_key.serialize())?;
864 writer.write_all(&$holder_tx.per_commitment_point.serialize())?;
866 writer.write_all(&byte_utils::be32_to_array($holder_tx.feerate_per_kw))?;
867 writer.write_all(&byte_utils::be64_to_array($holder_tx.htlc_outputs.len() as u64))?;
868 for &(ref htlc_output, ref sig, ref htlc_source) in $holder_tx.htlc_outputs.iter() {
869 serialize_htlc_in_commitment!(htlc_output);
870 if let &Some(ref their_sig) = sig {
872 writer.write_all(&their_sig.serialize_compact())?;
876 htlc_source.write(writer)?;
881 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
882 writer.write_all(&[1; 1])?;
883 serialize_holder_tx!(prev_holder_tx);
885 writer.write_all(&[0; 1])?;
888 serialize_holder_tx!(self.current_holder_commitment_tx);
890 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
891 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
893 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
894 for payment_preimage in self.payment_preimages.values() {
895 writer.write_all(&payment_preimage.0[..])?;
898 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
899 for event in self.pending_monitor_events.iter() {
901 MonitorEvent::HTLCEvent(upd) => {
905 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
909 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
910 for event in self.pending_events.iter() {
911 event.write(writer)?;
914 self.last_block_hash.write(writer)?;
916 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
917 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
918 writer.write_all(&byte_utils::be32_to_array(**target))?;
919 writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
920 for ev in events.iter() {
922 OnchainEvent::HTLCUpdate { ref htlc_update } => {
924 htlc_update.0.write(writer)?;
925 htlc_update.1.write(writer)?;
927 OnchainEvent::MaturingOutput { ref descriptor } => {
929 descriptor.write(writer)?;
935 (self.outputs_to_watch.len() as u64).write(writer)?;
936 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
938 (idx_scripts.len() as u64).write(writer)?;
939 for (idx, script) in idx_scripts.iter() {
941 script.write(writer)?;
944 self.onchain_tx_handler.write(writer)?;
946 self.lockdown_from_offchain.write(writer)?;
947 self.holder_tx_signed.write(writer)?;
953 impl<Signer: Sign> ChannelMonitor<Signer> {
954 pub(crate) fn new(keys: Signer, shutdown_pubkey: &PublicKey,
955 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
956 channel_parameters: &ChannelTransactionParameters,
957 funding_redeemscript: Script, channel_value_satoshis: u64,
958 commitment_transaction_number_obscure_factor: u64,
959 initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<Signer> {
961 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
962 let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
963 let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
964 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
965 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
967 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
968 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
969 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
970 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
972 let channel_keys_id = keys.channel_keys_id();
973 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
975 let secp_ctx = Secp256k1::new();
977 // block for Rust 1.34 compat
978 let (holder_commitment_tx, current_holder_commitment_number) = {
979 let trusted_tx = initial_holder_commitment_tx.trust();
980 let txid = trusted_tx.txid();
982 let tx_keys = trusted_tx.keys();
983 let holder_commitment_tx = HolderSignedTx {
985 revocation_key: tx_keys.revocation_key,
986 a_htlc_key: tx_keys.broadcaster_htlc_key,
987 b_htlc_key: tx_keys.countersignatory_htlc_key,
988 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
989 per_commitment_point: tx_keys.per_commitment_point,
990 feerate_per_kw: trusted_tx.feerate_per_kw(),
991 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
993 (holder_commitment_tx, trusted_tx.commitment_number())
996 let onchain_tx_handler =
997 OnchainTxHandler::new(destination_script.clone(), keys, channel_parameters.clone(), initial_holder_commitment_tx);
999 let mut outputs_to_watch = HashMap::new();
1000 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1003 latest_update_id: 0,
1004 commitment_transaction_number_obscure_factor,
1006 destination_script: destination_script.clone(),
1007 broadcasted_holder_revokable_script: None,
1008 counterparty_payment_script,
1012 holder_revocation_basepoint,
1014 current_counterparty_commitment_txid: None,
1015 prev_counterparty_commitment_txid: None,
1017 counterparty_tx_cache,
1018 funding_redeemscript,
1019 channel_value_satoshis,
1020 their_cur_revocation_points: None,
1022 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1024 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1025 counterparty_claimable_outpoints: HashMap::new(),
1026 counterparty_commitment_txn_on_chain: HashMap::new(),
1027 counterparty_hash_commitment_number: HashMap::new(),
1029 prev_holder_signed_commitment_tx: None,
1030 current_holder_commitment_tx: holder_commitment_tx,
1031 current_counterparty_commitment_number: 1 << 48,
1032 current_holder_commitment_number,
1034 payment_preimages: HashMap::new(),
1035 pending_monitor_events: Vec::new(),
1036 pending_events: Vec::new(),
1038 onchain_events_waiting_threshold_conf: HashMap::new(),
1043 lockdown_from_offchain: false,
1044 holder_tx_signed: false,
1046 last_block_hash: Default::default(),
1051 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1052 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1053 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1054 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1055 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1056 return Err(MonitorUpdateError("Previous secret did not match new one"));
1059 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1060 // events for now-revoked/fulfilled HTLCs.
1061 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1062 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1067 if !self.payment_preimages.is_empty() {
1068 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1069 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1070 let min_idx = self.get_min_seen_secret();
1071 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1073 self.payment_preimages.retain(|&k, _| {
1074 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1075 if k == htlc.payment_hash {
1079 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1080 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1081 if k == htlc.payment_hash {
1086 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1093 counterparty_hash_commitment_number.remove(&k);
1102 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1103 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1104 /// possibly future revocation/preimage information) to claim outputs where possible.
1105 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1106 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1107 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1108 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1109 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1111 for &(ref htlc, _) in &htlc_outputs {
1112 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1115 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1116 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1117 self.current_counterparty_commitment_txid = Some(txid);
1118 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1119 self.current_counterparty_commitment_number = commitment_number;
1120 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1121 match self.their_cur_revocation_points {
1122 Some(old_points) => {
1123 if old_points.0 == commitment_number + 1 {
1124 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1125 } else if old_points.0 == commitment_number + 2 {
1126 if let Some(old_second_point) = old_points.2 {
1127 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1129 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1132 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1136 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1139 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1140 for htlc in htlc_outputs {
1141 if htlc.0.transaction_output_index.is_some() {
1145 self.counterparty_tx_cache.per_htlc.insert(txid, htlcs);
1148 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1149 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1150 /// is important that any clones of this channel monitor (including remote clones) by kept
1151 /// up-to-date as our holder commitment transaction is updated.
1152 /// Panics if set_on_holder_tx_csv has never been called.
1153 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1154 // block for Rust 1.34 compat
1155 let mut new_holder_commitment_tx = {
1156 let trusted_tx = holder_commitment_tx.trust();
1157 let txid = trusted_tx.txid();
1158 let tx_keys = trusted_tx.keys();
1159 self.current_holder_commitment_number = trusted_tx.commitment_number();
1162 revocation_key: tx_keys.revocation_key,
1163 a_htlc_key: tx_keys.broadcaster_htlc_key,
1164 b_htlc_key: tx_keys.countersignatory_htlc_key,
1165 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1166 per_commitment_point: tx_keys.per_commitment_point,
1167 feerate_per_kw: trusted_tx.feerate_per_kw(),
1171 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1172 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1173 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1174 if self.holder_tx_signed {
1175 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1180 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1181 /// commitment_tx_infos which contain the payment hash have been revoked.
1182 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)
1183 where B::Target: BroadcasterInterface,
1184 F::Target: FeeEstimator,
1187 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1189 // If the channel is force closed, try to claim the output from this preimage.
1190 // First check if a counterparty commitment transaction has been broadcasted:
1191 macro_rules! claim_htlcs {
1192 ($commitment_number: expr, $txid: expr) => {
1193 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1194 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, None, broadcaster, fee_estimator, logger);
1197 if let Some(txid) = self.current_counterparty_commitment_txid {
1198 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1199 claim_htlcs!(*commitment_number, txid);
1203 if let Some(txid) = self.prev_counterparty_commitment_txid {
1204 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1205 claim_htlcs!(*commitment_number, txid);
1210 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1211 // claiming the HTLC output from each of the holder commitment transactions.
1212 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1213 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1214 // holder commitment transactions.
1215 if self.broadcasted_holder_revokable_script.is_some() {
1216 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1217 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1218 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1219 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx);
1220 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
1225 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1226 where B::Target: BroadcasterInterface,
1229 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1230 broadcaster.broadcast_transaction(tx);
1232 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1235 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1238 /// panics if the given update is not the next update by update_id.
1239 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1240 where B::Target: BroadcasterInterface,
1241 F::Target: FeeEstimator,
1244 // ChannelMonitor updates may be applied after force close if we receive a
1245 // preimage for a broadcasted commitment transaction HTLC output that we'd
1246 // like to claim on-chain. If this is the case, we no longer have guaranteed
1247 // access to the monitor's update ID, so we use a sentinel value instead.
1248 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1249 match updates.updates[0] {
1250 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1251 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1253 assert_eq!(updates.updates.len(), 1);
1254 } else if self.latest_update_id + 1 != updates.update_id {
1255 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1257 for update in updates.updates.iter() {
1259 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1260 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1261 if self.lockdown_from_offchain { panic!(); }
1262 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1264 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1265 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1266 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1268 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1269 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1270 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1272 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1273 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1274 self.provide_secret(*idx, *secret)?
1276 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1277 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1278 self.lockdown_from_offchain = true;
1279 if *should_broadcast {
1280 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1282 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");
1287 self.latest_update_id = updates.update_id;
1291 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1293 pub fn get_latest_update_id(&self) -> u64 {
1294 self.latest_update_id
1297 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1298 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1302 /// Gets a list of txids, with their output scripts (in the order they appear in the
1303 /// transaction), which we must learn about spends of via block_connected().
1305 /// (C-not exported) because we have no HashMap bindings
1306 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1307 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1308 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1309 // its trivial to do, double-check that here.
1310 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1311 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1313 &self.outputs_to_watch
1316 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1317 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1319 /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
1320 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1321 let mut ret = Vec::new();
1322 mem::swap(&mut ret, &mut self.pending_monitor_events);
1326 /// Gets the list of pending events which were generated by previous actions, clearing the list
1329 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1330 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1331 /// no internal locking in ChannelMonitors.
1332 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1333 let mut ret = Vec::new();
1334 mem::swap(&mut ret, &mut self.pending_events);
1338 /// Can only fail if idx is < get_min_seen_secret
1339 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1340 self.commitment_secrets.get_secret(idx)
1343 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1344 self.commitment_secrets.get_min_seen_secret()
1347 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1348 self.current_counterparty_commitment_number
1351 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1352 self.current_holder_commitment_number
1355 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1356 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1357 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1358 /// HTLC-Success/HTLC-Timeout transactions.
1359 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1360 /// revoked counterparty commitment tx
1361 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 {
1362 // Most secp and related errors trying to create keys means we have no hope of constructing
1363 // a spend transaction...so we return no transactions to broadcast
1364 let mut claimable_outpoints = Vec::new();
1365 let mut watch_outputs = Vec::new();
1367 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1368 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1370 macro_rules! ignore_error {
1371 ( $thing : expr ) => {
1374 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1379 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);
1380 if commitment_number >= self.get_min_seen_secret() {
1381 let secret = self.get_secret(commitment_number).unwrap();
1382 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1383 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1384 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
1385 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));
1387 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1388 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1390 // First, process non-htlc outputs (to_holder & to_counterparty)
1391 for (idx, outp) in tx.output.iter().enumerate() {
1392 if outp.script_pubkey == revokeable_p2wsh {
1393 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};
1394 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});
1398 // Then, try to find revoked htlc outputs
1399 if let Some(ref per_commitment_data) = per_commitment_option {
1400 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1401 if let Some(transaction_output_index) = htlc.transaction_output_index {
1402 if transaction_output_index as usize >= tx.output.len() ||
1403 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1404 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1406 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};
1407 claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable: true, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1412 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1413 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1414 // We're definitely a counterparty commitment transaction!
1415 log_trace!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1416 for (idx, outp) in tx.output.iter().enumerate() {
1417 watch_outputs.push((idx as u32, outp.clone()));
1419 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1421 macro_rules! check_htlc_fails {
1422 ($txid: expr, $commitment_tx: expr) => {
1423 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1424 for &(ref htlc, ref source_option) in outpoints.iter() {
1425 if let &Some(ref source) = source_option {
1426 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), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1427 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1428 hash_map::Entry::Occupied(mut entry) => {
1429 let e = entry.get_mut();
1430 e.retain(|ref event| {
1432 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1433 return htlc_update.0 != **source
1438 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1440 hash_map::Entry::Vacant(entry) => {
1441 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1449 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1450 check_htlc_fails!(txid, "current");
1452 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1453 check_htlc_fails!(txid, "counterparty");
1455 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1457 } else if let Some(per_commitment_data) = per_commitment_option {
1458 // While this isn't useful yet, there is a potential race where if a counterparty
1459 // revokes a state at the same time as the commitment transaction for that state is
1460 // confirmed, and the watchtower receives the block before the user, the user could
1461 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1462 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1463 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1465 for (idx, outp) in tx.output.iter().enumerate() {
1466 watch_outputs.push((idx as u32, outp.clone()));
1468 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1470 log_trace!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1472 macro_rules! check_htlc_fails {
1473 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1474 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1475 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1476 if let &Some(ref source) = source_option {
1477 // Check if the HTLC is present in the commitment transaction that was
1478 // broadcast, but not if it was below the dust limit, which we should
1479 // fail backwards immediately as there is no way for us to learn the
1480 // payment_preimage.
1481 // Note that if the dust limit were allowed to change between
1482 // commitment transactions we'd want to be check whether *any*
1483 // broadcastable commitment transaction has the HTLC in it, but it
1484 // cannot currently change after channel initialization, so we don't
1486 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1487 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1491 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);
1492 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
1493 hash_map::Entry::Occupied(mut entry) => {
1494 let e = entry.get_mut();
1495 e.retain(|ref event| {
1497 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1498 return htlc_update.0 != **source
1503 e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
1505 hash_map::Entry::Vacant(entry) => {
1506 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
1514 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1515 check_htlc_fails!(txid, "current", 'current_loop);
1517 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1518 check_htlc_fails!(txid, "previous", 'prev_loop);
1521 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
1522 for req in htlc_claim_reqs {
1523 claimable_outpoints.push(req);
1527 (claimable_outpoints, (commitment_txid, watch_outputs))
1530 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<ClaimRequest> {
1531 let mut claims = Vec::new();
1532 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
1533 if let Some(revocation_points) = self.their_cur_revocation_points {
1534 let revocation_point_option =
1535 // If the counterparty commitment tx is the latest valid state, use their latest
1536 // per-commitment point
1537 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1538 else if let Some(point) = revocation_points.2.as_ref() {
1539 // If counterparty commitment tx is the state previous to the latest valid state, use
1540 // their previous per-commitment point (non-atomicity of revocation means it's valid for
1541 // them to temporarily have two valid commitment txns from our viewpoint)
1542 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1544 if let Some(revocation_point) = revocation_point_option {
1545 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
1546 if let Some(transaction_output_index) = htlc.transaction_output_index {
1547 if let Some(transaction) = tx {
1548 if transaction_output_index as usize >= transaction.output.len() ||
1549 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1550 return claims; // Corrupted per_commitment_data, fuck this user
1555 if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) {
1559 let aggregable = if !htlc.offered { false } else { true };
1560 if preimage.is_some() || !htlc.offered {
1561 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() };
1562 claims.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
1572 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1573 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 {
1574 let htlc_txid = tx.txid();
1575 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1576 return (Vec::new(), None)
1579 macro_rules! ignore_error {
1580 ( $thing : expr ) => {
1583 Err(_) => return (Vec::new(), None)
1588 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1589 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1590 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1592 log_trace!(logger, "Counterparty HTLC broadcast {}:{}", htlc_txid, 0);
1593 let witness_data = InputMaterial::Revoked { per_commitment_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, input_descriptor: InputDescriptors::RevokedOutput, amount: tx.output[0].value, htlc: None, on_counterparty_tx_csv: self.counterparty_tx_cache.on_counterparty_tx_csv };
1594 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 });
1595 let outputs = vec![(0, tx.output[0].clone())];
1596 (claimable_outpoints, Some((htlc_txid, outputs)))
1599 // Returns (1) `ClaimRequest`s that can be given to the OnChainTxHandler, so that the handler can
1600 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1601 // script so we can detect whether a holder transaction has been seen on-chain.
1602 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx) -> (Vec<ClaimRequest>, Option<(Script, PublicKey, PublicKey)>) {
1603 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1605 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1606 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1608 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1609 if let Some(transaction_output_index) = htlc.transaction_output_index {
1610 claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
1611 witness_data: InputMaterial::HolderHTLC {
1612 preimage: if !htlc.offered {
1613 if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1614 Some(preimage.clone())
1616 // We can't build an HTLC-Success transaction without the preimage
1620 amount: htlc.amount_msat,
1625 (claim_requests, broadcasted_holder_revokable_script)
1628 // Returns holder HTLC outputs to watch and react to in case of spending.
1629 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1630 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1631 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1632 if let Some(transaction_output_index) = htlc.transaction_output_index {
1633 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1639 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1640 /// revoked using data in holder_claimable_outpoints.
1641 /// Should not be used if check_spend_revoked_transaction succeeds.
1642 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 {
1643 let commitment_txid = tx.txid();
1644 let mut claim_requests = Vec::new();
1645 let mut watch_outputs = Vec::new();
1647 macro_rules! wait_threshold_conf {
1648 ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1649 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
1650 match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
1651 hash_map::Entry::Occupied(mut entry) => {
1652 let e = entry.get_mut();
1653 e.retain(|ref event| {
1655 OnchainEvent::HTLCUpdate { ref htlc_update } => {
1656 return htlc_update.0 != $source
1661 e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
1663 hash_map::Entry::Vacant(entry) => {
1664 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
1670 macro_rules! append_onchain_update {
1671 ($updates: expr, $to_watch: expr) => {
1672 claim_requests = $updates.0;
1673 self.broadcasted_holder_revokable_script = $updates.1;
1674 watch_outputs.append(&mut $to_watch);
1678 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1679 let mut is_holder_tx = false;
1681 if self.current_holder_commitment_tx.txid == commitment_txid {
1682 is_holder_tx = true;
1683 log_trace!(logger, "Got latest holder commitment tx broadcast, searching for available HTLCs to claim");
1684 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1685 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1686 append_onchain_update!(res, to_watch);
1687 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1688 if holder_tx.txid == commitment_txid {
1689 is_holder_tx = true;
1690 log_trace!(logger, "Got previous holder commitment tx broadcast, searching for available HTLCs to claim");
1691 let res = self.get_broadcasted_holder_claims(holder_tx);
1692 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1693 append_onchain_update!(res, to_watch);
1697 macro_rules! fail_dust_htlcs_after_threshold_conf {
1698 ($holder_tx: expr) => {
1699 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1700 if htlc.transaction_output_index.is_none() {
1701 if let &Some(ref source) = source {
1702 wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
1710 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1711 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1712 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1716 (claim_requests, (commitment_txid, watch_outputs))
1719 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1720 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1721 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1722 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1723 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1724 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1725 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1726 /// out-of-band the other node operator to coordinate with him if option is available to you.
1727 /// In any-case, choice is up to the user.
1728 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1729 log_trace!(logger, "Getting signed latest holder commitment transaction!");
1730 self.holder_tx_signed = true;
1731 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
1732 let txid = commitment_tx.txid();
1733 let mut res = vec![commitment_tx];
1734 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1735 if let Some(vout) = htlc.0.transaction_output_index {
1736 let preimage = if !htlc.0.offered {
1737 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1738 // We can't build an HTLC-Success transaction without the preimage
1742 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1743 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1748 // 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.
1749 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1753 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1754 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1755 /// revoked commitment transaction.
1756 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1757 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1758 log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
1759 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
1760 let txid = commitment_tx.txid();
1761 let mut res = vec![commitment_tx];
1762 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1763 if let Some(vout) = htlc.0.transaction_output_index {
1764 let preimage = if !htlc.0.offered {
1765 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1766 // We can't build an HTLC-Success transaction without the preimage
1770 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1771 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1779 /// Processes transactions in a newly connected block, which may result in any of the following:
1780 /// - update the monitor's state against resolved HTLCs
1781 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1782 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1783 /// - detect settled outputs for later spending
1784 /// - schedule and bump any in-flight claims
1786 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1787 /// [`get_outputs_to_watch`].
1789 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1790 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)>)>
1791 where B::Target: BroadcasterInterface,
1792 F::Target: FeeEstimator,
1795 let txn_matched = self.filter_block(txdata);
1796 for tx in &txn_matched {
1797 let mut output_val = 0;
1798 for out in tx.output.iter() {
1799 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1800 output_val += out.value;
1801 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1805 let block_hash = header.block_hash();
1806 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1808 let mut watch_outputs = Vec::new();
1809 let mut claimable_outpoints = Vec::new();
1810 for tx in &txn_matched {
1811 if tx.input.len() == 1 {
1812 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1813 // commitment transactions and HTLC transactions will all only ever have one input,
1814 // which is an easy way to filter out any potential non-matching txn for lazy
1816 let prevout = &tx.input[0].previous_output;
1817 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1818 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1819 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1820 if !new_outputs.1.is_empty() {
1821 watch_outputs.push(new_outputs);
1823 if new_outpoints.is_empty() {
1824 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1825 if !new_outputs.1.is_empty() {
1826 watch_outputs.push(new_outputs);
1828 claimable_outpoints.append(&mut new_outpoints);
1830 claimable_outpoints.append(&mut new_outpoints);
1833 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
1834 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
1835 claimable_outpoints.append(&mut new_outpoints);
1836 if let Some(new_outputs) = new_outputs_option {
1837 watch_outputs.push(new_outputs);
1842 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1843 // can also be resolved in a few other ways which can have more than one output. Thus,
1844 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1845 self.is_resolving_htlc_output(&tx, height, &logger);
1847 self.is_paying_spendable_output(&tx, height, &logger);
1849 let should_broadcast = self.would_broadcast_at_height(height, &logger);
1850 if should_broadcast {
1851 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() }});
1853 if should_broadcast {
1854 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1855 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
1856 self.holder_tx_signed = true;
1857 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
1858 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
1859 if !new_outputs.is_empty() {
1860 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
1862 claimable_outpoints.append(&mut new_outpoints);
1864 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
1867 OnchainEvent::HTLCUpdate { htlc_update } => {
1868 log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
1869 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
1870 payment_hash: htlc_update.1,
1871 payment_preimage: None,
1872 source: htlc_update.0,
1875 OnchainEvent::MaturingOutput { descriptor } => {
1876 log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
1877 self.pending_events.push(Event::SpendableOutputs {
1878 outputs: vec![descriptor]
1885 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
1886 self.last_block_hash = block_hash;
1888 // Determine new outputs to watch by comparing against previously known outputs to watch,
1889 // updating the latter in the process.
1890 watch_outputs.retain(|&(ref txid, ref txouts)| {
1891 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
1892 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
1896 // If we see a transaction for which we registered outputs previously,
1897 // make sure the registered scriptpubkey at the expected index match
1898 // the actual transaction output one. We failed this case before #653.
1899 for tx in &txn_matched {
1900 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
1901 for idx_and_script in outputs.iter() {
1902 assert!((idx_and_script.0 as usize) < tx.output.len());
1903 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
1911 /// Determines if the disconnected block contained any transactions of interest and updates
1913 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
1914 where B::Target: BroadcasterInterface,
1915 F::Target: FeeEstimator,
1918 let block_hash = header.block_hash();
1919 log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
1921 if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
1923 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
1924 //- maturing spendable output has transaction paying us has been disconnected
1927 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
1929 self.last_block_hash = block_hash;
1932 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
1933 /// transactions thereof.
1934 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
1935 let mut matched_txn = HashSet::new();
1936 txdata.iter().filter(|&&(_, tx)| {
1937 let mut matches = self.spends_watched_output(tx);
1938 for input in tx.input.iter() {
1939 if matches { break; }
1940 if matched_txn.contains(&input.previous_output.txid) {
1945 matched_txn.insert(tx.txid());
1948 }).map(|(_, tx)| *tx).collect()
1951 /// Checks if a given transaction spends any watched outputs.
1952 fn spends_watched_output(&self, tx: &Transaction) -> bool {
1953 for input in tx.input.iter() {
1954 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
1955 for (idx, _script_pubkey) in outputs.iter() {
1956 if *idx == input.previous_output.vout {
1959 // If the expected script is a known type, check that the witness
1960 // appears to be spending the correct type (ie that the match would
1961 // actually succeed in BIP 158/159-style filters).
1962 if _script_pubkey.is_v0_p2wsh() {
1963 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
1964 } else if _script_pubkey.is_v0_p2wpkh() {
1965 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
1966 } else { panic!(); }
1977 fn would_broadcast_at_height<L: Deref>(&self, height: u32, logger: &L) -> bool where L::Target: Logger {
1978 // We need to consider all HTLCs which are:
1979 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
1980 // transactions and we'd end up in a race, or
1981 // * are in our latest holder commitment transaction, as this is the thing we will
1982 // broadcast if we go on-chain.
1983 // Note that we consider HTLCs which were below dust threshold here - while they don't
1984 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1985 // to the source, and if we don't fail the channel we will have to ensure that the next
1986 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1987 // easier to just fail the channel as this case should be rare enough anyway.
1988 macro_rules! scan_commitment {
1989 ($htlcs: expr, $holder_tx: expr) => {
1990 for ref htlc in $htlcs {
1991 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1992 // chain with enough room to claim the HTLC without our counterparty being able to
1993 // time out the HTLC first.
1994 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1995 // concern is being able to claim the corresponding inbound HTLC (on another
1996 // channel) before it expires. In fact, we don't even really care if our
1997 // counterparty here claims such an outbound HTLC after it expired as long as we
1998 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
1999 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2000 // we give ourselves a few blocks of headroom after expiration before going
2001 // on-chain for an expired HTLC.
2002 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2003 // from us until we've reached the point where we go on-chain with the
2004 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2005 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2006 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2007 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2008 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2009 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2010 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2011 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2012 // The final, above, condition is checked for statically in channelmanager
2013 // with CHECK_CLTV_EXPIRY_SANITY_2.
2014 let htlc_outbound = $holder_tx == htlc.offered;
2015 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2016 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2017 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2024 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2026 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2027 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2028 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2031 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2032 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2033 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2040 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2041 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2042 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2043 'outer_loop: for input in &tx.input {
2044 let mut payment_data = None;
2045 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2046 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2047 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2048 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2050 macro_rules! log_claim {
2051 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2052 // We found the output in question, but aren't failing it backwards
2053 // as we have no corresponding source and no valid counterparty commitment txid
2054 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2055 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2056 let outbound_htlc = $holder_tx == $htlc.offered;
2057 if ($holder_tx && revocation_sig_claim) ||
2058 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2059 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2060 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2061 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2062 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2064 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2065 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2066 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2067 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2072 macro_rules! check_htlc_valid_counterparty {
2073 ($counterparty_txid: expr, $htlc_output: expr) => {
2074 if let Some(txid) = $counterparty_txid {
2075 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2076 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2077 if let &Some(ref source) = pending_source {
2078 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2079 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2088 macro_rules! scan_commitment {
2089 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2090 for (ref htlc_output, source_option) in $htlcs {
2091 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2092 if let Some(ref source) = source_option {
2093 log_claim!($tx_info, $holder_tx, htlc_output, true);
2094 // We have a resolution of an HTLC either from one of our latest
2095 // holder commitment transactions or an unrevoked counterparty commitment
2096 // transaction. This implies we either learned a preimage, the HTLC
2097 // has timed out, or we screwed up. In any case, we should now
2098 // resolve the source HTLC with the original sender.
2099 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2100 } else if !$holder_tx {
2101 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2102 if payment_data.is_none() {
2103 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2106 if payment_data.is_none() {
2107 log_claim!($tx_info, $holder_tx, htlc_output, false);
2108 continue 'outer_loop;
2115 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2116 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2117 "our latest holder commitment tx", true);
2119 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2120 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2121 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2122 "our previous holder commitment tx", true);
2125 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2126 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2127 "counterparty commitment tx", false);
2130 // Check that scan_commitment, above, decided there is some source worth relaying an
2131 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2132 if let Some((source, payment_hash)) = payment_data {
2133 let mut payment_preimage = PaymentPreimage([0; 32]);
2134 if accepted_preimage_claim {
2135 if !self.pending_monitor_events.iter().any(
2136 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2137 payment_preimage.0.copy_from_slice(&input.witness[3]);
2138 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2140 payment_preimage: Some(payment_preimage),
2144 } else if offered_preimage_claim {
2145 if !self.pending_monitor_events.iter().any(
2146 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2147 upd.source == source
2149 payment_preimage.0.copy_from_slice(&input.witness[1]);
2150 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2152 payment_preimage: Some(payment_preimage),
2157 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);
2158 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2159 hash_map::Entry::Occupied(mut entry) => {
2160 let e = entry.get_mut();
2161 e.retain(|ref event| {
2163 OnchainEvent::HTLCUpdate { ref htlc_update } => {
2164 return htlc_update.0 != source
2169 e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
2171 hash_map::Entry::Vacant(entry) => {
2172 entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
2180 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2181 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2182 let mut spendable_output = None;
2183 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2184 if i > ::std::u16::MAX as usize {
2185 // While it is possible that an output exists on chain which is greater than the
2186 // 2^16th output in a given transaction, this is only possible if the output is not
2187 // in a lightning transaction and was instead placed there by some third party who
2188 // wishes to give us money for no reason.
2189 // Namely, any lightning transactions which we pre-sign will never have anywhere
2190 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2191 // scripts are not longer than one byte in length and because they are inherently
2192 // non-standard due to their size.
2193 // Thus, it is completely safe to ignore such outputs, and while it may result in
2194 // us ignoring non-lightning fund to us, that is only possible if someone fills
2195 // nearly a full block with garbage just to hit this case.
2198 if outp.script_pubkey == self.destination_script {
2199 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2200 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2201 output: outp.clone(),
2204 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2205 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2206 spendable_output = Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2207 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2208 per_commitment_point: broadcasted_holder_revokable_script.1,
2209 to_self_delay: self.on_holder_tx_csv,
2210 output: outp.clone(),
2211 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2212 channel_keys_id: self.channel_keys_id,
2213 channel_value_satoshis: self.channel_value_satoshis,
2217 } else if self.counterparty_payment_script == outp.script_pubkey {
2218 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2219 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2220 output: outp.clone(),
2221 channel_keys_id: self.channel_keys_id,
2222 channel_value_satoshis: self.channel_value_satoshis,
2225 } else if outp.script_pubkey == self.shutdown_script {
2226 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2227 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2228 output: outp.clone(),
2232 if let Some(spendable_output) = spendable_output {
2233 log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
2234 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
2235 hash_map::Entry::Occupied(mut entry) => {
2236 let e = entry.get_mut();
2237 e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
2239 hash_map::Entry::Vacant(entry) => {
2240 entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
2247 /// `Persist` defines behavior for persisting channel monitors: this could mean
2248 /// writing once to disk, and/or uploading to one or more backup services.
2250 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2251 /// to disk/backups. And, on every update, you **must** persist either the
2252 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2253 /// of situations such as revoking a transaction, then crashing before this
2254 /// revocation can be persisted, then unintentionally broadcasting a revoked
2255 /// transaction and losing money. This is a risk because previous channel states
2256 /// are toxic, so it's important that whatever channel state is persisted is
2257 /// kept up-to-date.
2258 pub trait Persist<ChannelSigner: Sign>: Send + Sync {
2259 /// Persist a new channel's data. The data can be stored any way you want, but
2260 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2261 /// it is up to you to maintain a correct mapping between the outpoint and the
2262 /// stored channel data). Note that you **must** persist every new monitor to
2263 /// disk. See the `Persist` trait documentation for more details.
2265 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2266 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2268 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2269 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2270 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2272 /// Update one channel's data. The provided `ChannelMonitor` has already
2273 /// applied the given update.
2275 /// Note that on every update, you **must** persist either the
2276 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2277 /// the `Persist` trait documentation for more details.
2279 /// If an implementer chooses to persist the updates only, they need to make
2280 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2281 /// the set of channel monitors is given to the `ChannelManager`
2282 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2283 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2284 /// persisted, then there is no need to persist individual updates.
2286 /// Note that there could be a performance tradeoff between persisting complete
2287 /// channel monitors on every update vs. persisting only updates and applying
2288 /// them in batches. The size of each monitor grows `O(number of state updates)`
2289 /// whereas updates are small and `O(1)`.
2291 /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
2292 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2293 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2295 /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
2296 /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
2297 /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
2298 /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
2299 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2304 pub struct MonitorTraits<CM: DerefMut<Target=ChannelMonitor<Signer>>, Signer: Sign, T: Deref, F: Deref, L: Deref> {
2310 pub fee_estimator: F,
2315 impl<CM: DerefMut<Target=ChannelMonitor<Signer>>, Signer: Sign, T: Deref, F: Deref, L: Deref>
2316 chain::Listen for MonitorTraits<CM, Signer, T, F, L>
2318 T::Target: BroadcasterInterface,
2319 F::Target: FeeEstimator,
2322 fn block_connected(&mut self, block: &Block, height: u32) {
2323 let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
2324 self.monitor.block_connected(&block.header, &txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
2327 fn block_disconnected(&mut self, header: &BlockHeader, height: u32) {
2328 self.monitor.block_disconnected(header, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
2332 const MAX_ALLOC_SIZE: usize = 64*1024;
2334 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
2335 for (BlockHash, ChannelMonitor<Signer>) {
2336 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
2337 macro_rules! unwrap_obj {
2341 Err(_) => return Err(DecodeError::InvalidValue),
2346 let _ver: u8 = Readable::read(reader)?;
2347 let min_ver: u8 = Readable::read(reader)?;
2348 if min_ver > SERIALIZATION_VERSION {
2349 return Err(DecodeError::UnknownVersion);
2352 let latest_update_id: u64 = Readable::read(reader)?;
2353 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2355 let destination_script = Readable::read(reader)?;
2356 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2358 let revokable_address = Readable::read(reader)?;
2359 let per_commitment_point = Readable::read(reader)?;
2360 let revokable_script = Readable::read(reader)?;
2361 Some((revokable_address, per_commitment_point, revokable_script))
2364 _ => return Err(DecodeError::InvalidValue),
2366 let counterparty_payment_script = Readable::read(reader)?;
2367 let shutdown_script = Readable::read(reader)?;
2369 let channel_keys_id = Readable::read(reader)?;
2370 let holder_revocation_basepoint = Readable::read(reader)?;
2371 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2372 // barely-init'd ChannelMonitors that we can't do anything with.
2373 let outpoint = OutPoint {
2374 txid: Readable::read(reader)?,
2375 index: Readable::read(reader)?,
2377 let funding_info = (outpoint, Readable::read(reader)?);
2378 let current_counterparty_commitment_txid = Readable::read(reader)?;
2379 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2381 let counterparty_tx_cache = Readable::read(reader)?;
2382 let funding_redeemscript = Readable::read(reader)?;
2383 let channel_value_satoshis = Readable::read(reader)?;
2385 let their_cur_revocation_points = {
2386 let first_idx = <U48 as Readable>::read(reader)?.0;
2390 let first_point = Readable::read(reader)?;
2391 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2392 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2393 Some((first_idx, first_point, None))
2395 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2400 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2402 let commitment_secrets = Readable::read(reader)?;
2404 macro_rules! read_htlc_in_commitment {
2407 let offered: bool = Readable::read(reader)?;
2408 let amount_msat: u64 = Readable::read(reader)?;
2409 let cltv_expiry: u32 = Readable::read(reader)?;
2410 let payment_hash: PaymentHash = Readable::read(reader)?;
2411 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2413 HTLCOutputInCommitment {
2414 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2420 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2421 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2422 for _ in 0..counterparty_claimable_outpoints_len {
2423 let txid: Txid = Readable::read(reader)?;
2424 let htlcs_count: u64 = Readable::read(reader)?;
2425 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2426 for _ in 0..htlcs_count {
2427 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2429 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2430 return Err(DecodeError::InvalidValue);
2434 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2435 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2436 for _ in 0..counterparty_commitment_txn_on_chain_len {
2437 let txid: Txid = Readable::read(reader)?;
2438 let commitment_number = <U48 as Readable>::read(reader)?.0;
2439 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2440 return Err(DecodeError::InvalidValue);
2444 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2445 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2446 for _ in 0..counterparty_hash_commitment_number_len {
2447 let payment_hash: PaymentHash = Readable::read(reader)?;
2448 let commitment_number = <U48 as Readable>::read(reader)?.0;
2449 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2450 return Err(DecodeError::InvalidValue);
2454 macro_rules! read_holder_tx {
2457 let txid = Readable::read(reader)?;
2458 let revocation_key = Readable::read(reader)?;
2459 let a_htlc_key = Readable::read(reader)?;
2460 let b_htlc_key = Readable::read(reader)?;
2461 let delayed_payment_key = Readable::read(reader)?;
2462 let per_commitment_point = Readable::read(reader)?;
2463 let feerate_per_kw: u32 = Readable::read(reader)?;
2465 let htlcs_len: u64 = Readable::read(reader)?;
2466 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2467 for _ in 0..htlcs_len {
2468 let htlc = read_htlc_in_commitment!();
2469 let sigs = match <u8 as Readable>::read(reader)? {
2471 1 => Some(Readable::read(reader)?),
2472 _ => return Err(DecodeError::InvalidValue),
2474 htlcs.push((htlc, sigs, Readable::read(reader)?));
2479 revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, per_commitment_point, feerate_per_kw,
2486 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2489 Some(read_holder_tx!())
2491 _ => return Err(DecodeError::InvalidValue),
2493 let current_holder_commitment_tx = read_holder_tx!();
2495 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2496 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2498 let payment_preimages_len: u64 = Readable::read(reader)?;
2499 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2500 for _ in 0..payment_preimages_len {
2501 let preimage: PaymentPreimage = Readable::read(reader)?;
2502 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2503 if let Some(_) = payment_preimages.insert(hash, preimage) {
2504 return Err(DecodeError::InvalidValue);
2508 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2509 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2510 for _ in 0..pending_monitor_events_len {
2511 let ev = match <u8 as Readable>::read(reader)? {
2512 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2513 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2514 _ => return Err(DecodeError::InvalidValue)
2516 pending_monitor_events.push(ev);
2519 let pending_events_len: u64 = Readable::read(reader)?;
2520 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2521 for _ in 0..pending_events_len {
2522 if let Some(event) = MaybeReadable::read(reader)? {
2523 pending_events.push(event);
2527 let last_block_hash: BlockHash = Readable::read(reader)?;
2529 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2530 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2531 for _ in 0..waiting_threshold_conf_len {
2532 let height_target = Readable::read(reader)?;
2533 let events_len: u64 = Readable::read(reader)?;
2534 let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
2535 for _ in 0..events_len {
2536 let ev = match <u8 as Readable>::read(reader)? {
2538 let htlc_source = Readable::read(reader)?;
2539 let hash = Readable::read(reader)?;
2540 OnchainEvent::HTLCUpdate {
2541 htlc_update: (htlc_source, hash)
2545 let descriptor = Readable::read(reader)?;
2546 OnchainEvent::MaturingOutput {
2550 _ => return Err(DecodeError::InvalidValue),
2554 onchain_events_waiting_threshold_conf.insert(height_target, events);
2557 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2558 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>>())));
2559 for _ in 0..outputs_to_watch_len {
2560 let txid = Readable::read(reader)?;
2561 let outputs_len: u64 = Readable::read(reader)?;
2562 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2563 for _ in 0..outputs_len {
2564 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2566 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2567 return Err(DecodeError::InvalidValue);
2570 let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
2572 let lockdown_from_offchain = Readable::read(reader)?;
2573 let holder_tx_signed = Readable::read(reader)?;
2575 Ok((last_block_hash.clone(), ChannelMonitor {
2577 commitment_transaction_number_obscure_factor,
2580 broadcasted_holder_revokable_script,
2581 counterparty_payment_script,
2585 holder_revocation_basepoint,
2587 current_counterparty_commitment_txid,
2588 prev_counterparty_commitment_txid,
2590 counterparty_tx_cache,
2591 funding_redeemscript,
2592 channel_value_satoshis,
2593 their_cur_revocation_points,
2598 counterparty_claimable_outpoints,
2599 counterparty_commitment_txn_on_chain,
2600 counterparty_hash_commitment_number,
2602 prev_holder_signed_commitment_tx,
2603 current_holder_commitment_tx,
2604 current_counterparty_commitment_number,
2605 current_holder_commitment_number,
2608 pending_monitor_events,
2611 onchain_events_waiting_threshold_conf,
2616 lockdown_from_offchain,
2620 secp_ctx: Secp256k1::new(),
2627 use bitcoin::blockdata::script::{Script, Builder};
2628 use bitcoin::blockdata::opcodes;
2629 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2630 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2631 use bitcoin::util::bip143;
2632 use bitcoin::hashes::Hash;
2633 use bitcoin::hashes::sha256::Hash as Sha256;
2634 use bitcoin::hashes::hex::FromHex;
2635 use bitcoin::hash_types::Txid;
2637 use chain::channelmonitor::ChannelMonitor;
2638 use chain::transaction::OutPoint;
2639 use ln::channelmanager::{PaymentPreimage, PaymentHash};
2640 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
2642 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
2643 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2644 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2645 use bitcoin::secp256k1::Secp256k1;
2646 use std::sync::{Arc, Mutex};
2647 use chain::keysinterface::InMemorySigner;
2650 fn test_prune_preimages() {
2651 let secp_ctx = Secp256k1::new();
2652 let logger = Arc::new(TestLogger::new());
2653 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
2654 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
2656 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2657 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2659 let mut preimages = Vec::new();
2662 let preimage = PaymentPreimage([i; 32]);
2663 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2664 preimages.push((preimage, hash));
2668 macro_rules! preimages_slice_to_htlc_outputs {
2669 ($preimages_slice: expr) => {
2671 let mut res = Vec::new();
2672 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2673 res.push((HTLCOutputInCommitment {
2677 payment_hash: preimage.1.clone(),
2678 transaction_output_index: Some(idx as u32),
2685 macro_rules! preimages_to_holder_htlcs {
2686 ($preimages_slice: expr) => {
2688 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2689 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2695 macro_rules! test_preimages_exist {
2696 ($preimages_slice: expr, $monitor: expr) => {
2697 for preimage in $preimages_slice {
2698 assert!($monitor.payment_preimages.contains_key(&preimage.1));
2703 let keys = InMemorySigner::new(
2705 SecretKey::from_slice(&[41; 32]).unwrap(),
2706 SecretKey::from_slice(&[41; 32]).unwrap(),
2707 SecretKey::from_slice(&[41; 32]).unwrap(),
2708 SecretKey::from_slice(&[41; 32]).unwrap(),
2709 SecretKey::from_slice(&[41; 32]).unwrap(),
2715 let counterparty_pubkeys = ChannelPublicKeys {
2716 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2717 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2718 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
2719 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
2720 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
2722 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
2723 let channel_parameters = ChannelTransactionParameters {
2724 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
2725 holder_selected_contest_delay: 66,
2726 is_outbound_from_holder: true,
2727 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
2728 pubkeys: counterparty_pubkeys,
2729 selected_contest_delay: 67,
2731 funding_outpoint: Some(funding_outpoint),
2733 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2735 let mut monitor = ChannelMonitor::new(keys,
2736 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
2737 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2738 &channel_parameters,
2739 Script::new(), 46, 0,
2740 HolderCommitmentTransaction::dummy());
2742 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2743 let dummy_txid = dummy_tx.txid();
2744 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2745 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2746 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2747 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2748 for &(ref preimage, ref hash) in preimages.iter() {
2749 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2752 // Now provide a secret, pruning preimages 10-15
2753 let mut secret = [0; 32];
2754 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2755 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2756 assert_eq!(monitor.payment_preimages.len(), 15);
2757 test_preimages_exist!(&preimages[0..10], monitor);
2758 test_preimages_exist!(&preimages[15..20], monitor);
2760 // Now provide a further secret, pruning preimages 15-17
2761 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2762 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2763 assert_eq!(monitor.payment_preimages.len(), 13);
2764 test_preimages_exist!(&preimages[0..10], monitor);
2765 test_preimages_exist!(&preimages[17..20], monitor);
2767 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2768 // previous commitment tx's preimages too
2769 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2770 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2771 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2772 assert_eq!(monitor.payment_preimages.len(), 12);
2773 test_preimages_exist!(&preimages[0..10], monitor);
2774 test_preimages_exist!(&preimages[18..20], monitor);
2776 // But if we do it again, we'll prune 5-10
2777 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2778 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2779 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2780 assert_eq!(monitor.payment_preimages.len(), 5);
2781 test_preimages_exist!(&preimages[0..5], monitor);
2785 fn test_claim_txn_weight_computation() {
2786 // We test Claim txn weight, knowing that we want expected weigth and
2787 // not actual case to avoid sigs and time-lock delays hell variances.
2789 let secp_ctx = Secp256k1::new();
2790 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2791 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2792 let mut sum_actual_sigs = 0;
2794 macro_rules! sign_input {
2795 ($sighash_parts: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2796 let htlc = HTLCOutputInCommitment {
2797 offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2799 cltv_expiry: 2 << 16,
2800 payment_hash: PaymentHash([1; 32]),
2801 transaction_output_index: Some($idx as u32),
2803 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2804 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
2805 let sig = secp_ctx.sign(&sighash, &privkey);
2806 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
2807 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
2808 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
2809 if *$input_type == InputDescriptors::RevokedOutput {
2810 $sighash_parts.access_witness($idx).push(vec!(1));
2811 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2812 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
2813 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2814 $sighash_parts.access_witness($idx).push(vec![0]);
2816 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
2818 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
2819 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
2820 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
2821 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
2825 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2826 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2828 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
2829 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2831 claim_tx.input.push(TxIn {
2832 previous_output: BitcoinOutPoint {
2836 script_sig: Script::new(),
2837 sequence: 0xfffffffd,
2838 witness: Vec::new(),
2841 claim_tx.output.push(TxOut {
2842 script_pubkey: script_pubkey.clone(),
2845 let base_weight = claim_tx.get_weight();
2846 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2848 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2849 for (idx, inp) in inputs_des.iter().enumerate() {
2850 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2853 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2855 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2856 claim_tx.input.clear();
2857 sum_actual_sigs = 0;
2859 claim_tx.input.push(TxIn {
2860 previous_output: BitcoinOutPoint {
2864 script_sig: Script::new(),
2865 sequence: 0xfffffffd,
2866 witness: Vec::new(),
2869 let base_weight = claim_tx.get_weight();
2870 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2872 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2873 for (idx, inp) in inputs_des.iter().enumerate() {
2874 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2877 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
2879 // Justice tx with 1 revoked HTLC-Success tx output
2880 claim_tx.input.clear();
2881 sum_actual_sigs = 0;
2882 claim_tx.input.push(TxIn {
2883 previous_output: BitcoinOutPoint {
2887 script_sig: Script::new(),
2888 sequence: 0xfffffffd,
2889 witness: Vec::new(),
2891 let base_weight = claim_tx.get_weight();
2892 let inputs_des = vec![InputDescriptors::RevokedOutput];
2894 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
2895 for (idx, inp) in inputs_des.iter().enumerate() {
2896 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
2899 assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
2902 // Further testing is done in the ChannelManager integration tests.