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Merge pull request #2323 from ariard/2023-05-remove-ariard-pgp-key
[rust-lightning] / lightning / src / chain / channelmonitor.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
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
8 // licenses.
9
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
11 //! here.
12 //!
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.
16 //!
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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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.
22
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{OutPoint as BitcoinOutPoint, TxOut, Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
27
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
31
32 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
33 use bitcoin::secp256k1::{SecretKey, PublicKey};
34 use bitcoin::secp256k1;
35
36 use crate::ln::{PaymentHash, PaymentPreimage};
37 use crate::ln::msgs::DecodeError;
38 use crate::ln::chan_utils;
39 use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use crate::ln::channelmanager::{HTLCSource, SentHTLCId};
41 use crate::chain;
42 use crate::chain::{BestBlock, WatchedOutput};
43 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
44 use crate::chain::transaction::{OutPoint, TransactionData};
45 use crate::sign::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
46 #[cfg(anchors)]
47 use crate::chain::onchaintx::ClaimEvent;
48 use crate::chain::onchaintx::OnchainTxHandler;
49 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
50 use crate::chain::Filter;
51 use crate::util::logger::Logger;
52 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
53 use crate::util::byte_utils;
54 use crate::events::Event;
55 #[cfg(anchors)]
56 use crate::events::bump_transaction::{AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
57
58 use crate::prelude::*;
59 use core::{cmp, mem};
60 use crate::io::{self, Error};
61 use core::convert::TryInto;
62 use core::ops::Deref;
63 use crate::sync::{Mutex, LockTestExt};
64
65 /// An update generated by the underlying channel itself which contains some new information the
66 /// [`ChannelMonitor`] should be made aware of.
67 ///
68 /// Because this represents only a small number of updates to the underlying state, it is generally
69 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
70 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
71 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
72 #[derive(Clone, PartialEq, Eq)]
73 #[must_use]
74 pub struct ChannelMonitorUpdate {
75         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
76         /// The sequence number of this update. Updates *must* be replayed in-order according to this
77         /// sequence number (and updates may panic if they are not). The update_id values are strictly
78         /// increasing and increase by one for each new update, with two exceptions specified below.
79         ///
80         /// This sequence number is also used to track up to which points updates which returned
81         /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
82         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
83         ///
84         /// The only instances we allow where update_id values are not strictly increasing have a
85         /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
86         /// will force close the channel by broadcasting the latest commitment transaction or
87         /// special post-force-close updates, like providing preimages necessary to claim outputs on the
88         /// broadcast commitment transaction. See its docs for more details.
89         ///
90         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
91         pub update_id: u64,
92 }
93
94 /// The update ID used for a [`ChannelMonitorUpdate`] that is either:
95 ///
96 ///     (1) attempting to force close the channel by broadcasting our latest commitment transaction or
97 ///     (2) providing a preimage (after the channel has been force closed) from a forward link that
98 ///             allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
99 ///             commitment transaction.
100 ///
101 /// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
102 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
103
104 impl Writeable for ChannelMonitorUpdate {
105         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
106                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
107                 self.update_id.write(w)?;
108                 (self.updates.len() as u64).write(w)?;
109                 for update_step in self.updates.iter() {
110                         update_step.write(w)?;
111                 }
112                 write_tlv_fields!(w, {});
113                 Ok(())
114         }
115 }
116 impl Readable for ChannelMonitorUpdate {
117         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
118                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
119                 let update_id: u64 = Readable::read(r)?;
120                 let len: u64 = Readable::read(r)?;
121                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
122                 for _ in 0..len {
123                         if let Some(upd) = MaybeReadable::read(r)? {
124                                 updates.push(upd);
125                         }
126                 }
127                 read_tlv_fields!(r, {});
128                 Ok(Self { update_id, updates })
129         }
130 }
131
132 /// An event to be processed by the ChannelManager.
133 #[derive(Clone, PartialEq, Eq)]
134 pub enum MonitorEvent {
135         /// A monitor event containing an HTLCUpdate.
136         HTLCEvent(HTLCUpdate),
137
138         /// A monitor event that the Channel's commitment transaction was confirmed.
139         CommitmentTxConfirmed(OutPoint),
140
141         /// Indicates a [`ChannelMonitor`] update has completed. See
142         /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
143         ///
144         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
145         Completed {
146                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
147                 funding_txo: OutPoint,
148                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
149                 /// [`ChannelMonitor::get_latest_update_id`].
150                 ///
151                 /// Note that this should only be set to a given update's ID if all previous updates for the
152                 /// same [`ChannelMonitor`] have been applied and persisted.
153                 monitor_update_id: u64,
154         },
155
156         /// Indicates a [`ChannelMonitor`] update has failed. See
157         /// [`ChannelMonitorUpdateStatus::PermanentFailure`] for more information on how this is used.
158         ///
159         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
160         UpdateFailed(OutPoint),
161 }
162 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
163         // Note that Completed and UpdateFailed are currently never serialized to disk as they are
164         // generated only in ChainMonitor
165         (0, Completed) => {
166                 (0, funding_txo, required),
167                 (2, monitor_update_id, required),
168         },
169 ;
170         (2, HTLCEvent),
171         (4, CommitmentTxConfirmed),
172         (6, UpdateFailed),
173 );
174
175 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
176 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
177 /// preimage claim backward will lead to loss of funds.
178 #[derive(Clone, PartialEq, Eq)]
179 pub struct HTLCUpdate {
180         pub(crate) payment_hash: PaymentHash,
181         pub(crate) payment_preimage: Option<PaymentPreimage>,
182         pub(crate) source: HTLCSource,
183         pub(crate) htlc_value_satoshis: Option<u64>,
184 }
185 impl_writeable_tlv_based!(HTLCUpdate, {
186         (0, payment_hash, required),
187         (1, htlc_value_satoshis, option),
188         (2, source, required),
189         (4, payment_preimage, option),
190 });
191
192 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
193 /// instead claiming it in its own individual transaction.
194 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
195 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
196 /// HTLC-Success transaction.
197 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
198 /// transaction confirmed (and we use it in a few more, equivalent, places).
199 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
200 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
201 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
202 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
203 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
204 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
205 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
206 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
207 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
208 /// accurate block height.
209 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
210 /// with at worst this delay, so we are not only using this value as a mercy for them but also
211 /// us as a safeguard to delay with enough time.
212 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
213 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
214 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
215 /// losing money.
216 ///
217 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
218 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
219 /// by a  [`ChannelMonitor`] may be incorrect.
220 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
221 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
222 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
223 // keep bumping another claim tx to solve the outpoint.
224 pub const ANTI_REORG_DELAY: u32 = 6;
225 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
226 /// refuse to accept a new HTLC.
227 ///
228 /// This is used for a few separate purposes:
229 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
230 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
231 ///    fail this HTLC,
232 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
233 ///    condition with the above), we will fail this HTLC without telling the user we received it,
234 ///
235 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
236 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
237 ///
238 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
239 /// in a race condition between the user connecting a block (which would fail it) and the user
240 /// providing us the preimage (which would claim it).
241 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
242
243 // TODO(devrandom) replace this with HolderCommitmentTransaction
244 #[derive(Clone, PartialEq, Eq)]
245 struct HolderSignedTx {
246         /// txid of the transaction in tx, just used to make comparison faster
247         txid: Txid,
248         revocation_key: PublicKey,
249         a_htlc_key: PublicKey,
250         b_htlc_key: PublicKey,
251         delayed_payment_key: PublicKey,
252         per_commitment_point: PublicKey,
253         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
254         to_self_value_sat: u64,
255         feerate_per_kw: u32,
256 }
257 impl_writeable_tlv_based!(HolderSignedTx, {
258         (0, txid, required),
259         // Note that this is filled in with data from OnchainTxHandler if it's missing.
260         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
261         (1, to_self_value_sat, (default_value, u64::max_value())),
262         (2, revocation_key, required),
263         (4, a_htlc_key, required),
264         (6, b_htlc_key, required),
265         (8, delayed_payment_key, required),
266         (10, per_commitment_point, required),
267         (12, feerate_per_kw, required),
268         (14, htlc_outputs, vec_type)
269 });
270
271 #[cfg(anchors)]
272 impl HolderSignedTx {
273         fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
274                 self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
275                         if let Some(_) = htlc.transaction_output_index {
276                                 Some(htlc.clone())
277                         } else {
278                                 None
279                         }
280                 })
281                 .collect()
282         }
283 }
284
285 /// We use this to track static counterparty commitment transaction data and to generate any
286 /// justice or 2nd-stage preimage/timeout transactions.
287 #[derive(PartialEq, Eq)]
288 struct CounterpartyCommitmentParameters {
289         counterparty_delayed_payment_base_key: PublicKey,
290         counterparty_htlc_base_key: PublicKey,
291         on_counterparty_tx_csv: u16,
292 }
293
294 impl Writeable for CounterpartyCommitmentParameters {
295         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
296                 w.write_all(&(0 as u64).to_be_bytes())?;
297                 write_tlv_fields!(w, {
298                         (0, self.counterparty_delayed_payment_base_key, required),
299                         (2, self.counterparty_htlc_base_key, required),
300                         (4, self.on_counterparty_tx_csv, required),
301                 });
302                 Ok(())
303         }
304 }
305 impl Readable for CounterpartyCommitmentParameters {
306         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
307                 let counterparty_commitment_transaction = {
308                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
309                         // used. Read it for compatibility.
310                         let per_htlc_len: u64 = Readable::read(r)?;
311                         for _  in 0..per_htlc_len {
312                                 let _txid: Txid = Readable::read(r)?;
313                                 let htlcs_count: u64 = Readable::read(r)?;
314                                 for _ in 0..htlcs_count {
315                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
316                                 }
317                         }
318
319                         let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
320                         let mut counterparty_htlc_base_key = RequiredWrapper(None);
321                         let mut on_counterparty_tx_csv: u16 = 0;
322                         read_tlv_fields!(r, {
323                                 (0, counterparty_delayed_payment_base_key, required),
324                                 (2, counterparty_htlc_base_key, required),
325                                 (4, on_counterparty_tx_csv, required),
326                         });
327                         CounterpartyCommitmentParameters {
328                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
329                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
330                                 on_counterparty_tx_csv,
331                         }
332                 };
333                 Ok(counterparty_commitment_transaction)
334         }
335 }
336
337 /// An entry for an [`OnchainEvent`], stating the block height and hash when the event was
338 /// observed, as well as the transaction causing it.
339 ///
340 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
341 #[derive(PartialEq, Eq)]
342 struct OnchainEventEntry {
343         txid: Txid,
344         height: u32,
345         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
346         event: OnchainEvent,
347         transaction: Option<Transaction>, // Added as optional, but always filled in, in LDK 0.0.110
348 }
349
350 impl OnchainEventEntry {
351         fn confirmation_threshold(&self) -> u32 {
352                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
353                 match self.event {
354                         OnchainEvent::MaturingOutput {
355                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
356                         } => {
357                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
358                                 // it's broadcastable when we see the previous block.
359                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
360                         },
361                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
362                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
363                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
364                                 // it's broadcastable when we see the previous block.
365                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
366                         },
367                         _ => {},
368                 }
369                 conf_threshold
370         }
371
372         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
373                 best_block.height() >= self.confirmation_threshold()
374         }
375 }
376
377 /// The (output index, sats value) for the counterparty's output in a commitment transaction.
378 ///
379 /// This was added as an `Option` in 0.0.110.
380 type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
381
382 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
383 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
384 #[derive(PartialEq, Eq)]
385 enum OnchainEvent {
386         /// An outbound HTLC failing after a transaction is confirmed. Used
387         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
388         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
389         ///    on-chain (either because it was not fully committed to or it was dust).
390         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
391         /// appearing only as an `HTLCSpendConfirmation`, below.
392         HTLCUpdate {
393                 source: HTLCSource,
394                 payment_hash: PaymentHash,
395                 htlc_value_satoshis: Option<u64>,
396                 /// None in the second case, above, ie when there is no relevant output in the commitment
397                 /// transaction which appeared on chain.
398                 commitment_tx_output_idx: Option<u32>,
399         },
400         /// An output waiting on [`ANTI_REORG_DELAY`] confirmations before we hand the user the
401         /// [`SpendableOutputDescriptor`].
402         MaturingOutput {
403                 descriptor: SpendableOutputDescriptor,
404         },
405         /// A spend of the funding output, either a commitment transaction or a cooperative closing
406         /// transaction.
407         FundingSpendConfirmation {
408                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
409                 /// commitment transaction, and this is the delay on the to_self output).
410                 on_local_output_csv: Option<u16>,
411                 /// If the funding spend transaction was a known remote commitment transaction, we track
412                 /// the output index and amount of the counterparty's `to_self` output here.
413                 ///
414                 /// This allows us to generate a [`Balance::CounterpartyRevokedOutputClaimable`] for the
415                 /// counterparty output.
416                 commitment_tx_to_counterparty_output: CommitmentTxCounterpartyOutputInfo,
417         },
418         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
419         /// is constructed. This is used when
420         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
421         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
422         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
423         ///  * an inbound HTLC is claimed by us (with a preimage).
424         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
425         ///    signature.
426         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by an
427         ///    HTLC-Success/HTLC-Failure transaction (and is still claimable with a revocation
428         ///    signature).
429         HTLCSpendConfirmation {
430                 commitment_tx_output_idx: u32,
431                 /// If the claim was made by either party with a preimage, this is filled in
432                 preimage: Option<PaymentPreimage>,
433                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
434                 /// we set this to the output CSV value which we will have to wait until to spend the
435                 /// output (and generate a SpendableOutput event).
436                 on_to_local_output_csv: Option<u16>,
437         },
438 }
439
440 impl Writeable for OnchainEventEntry {
441         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
442                 write_tlv_fields!(writer, {
443                         (0, self.txid, required),
444                         (1, self.transaction, option),
445                         (2, self.height, required),
446                         (3, self.block_hash, option),
447                         (4, self.event, required),
448                 });
449                 Ok(())
450         }
451 }
452
453 impl MaybeReadable for OnchainEventEntry {
454         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
455                 let mut txid = Txid::all_zeros();
456                 let mut transaction = None;
457                 let mut block_hash = None;
458                 let mut height = 0;
459                 let mut event = UpgradableRequired(None);
460                 read_tlv_fields!(reader, {
461                         (0, txid, required),
462                         (1, transaction, option),
463                         (2, height, required),
464                         (3, block_hash, option),
465                         (4, event, upgradable_required),
466                 });
467                 Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
468         }
469 }
470
471 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
472         (0, HTLCUpdate) => {
473                 (0, source, required),
474                 (1, htlc_value_satoshis, option),
475                 (2, payment_hash, required),
476                 (3, commitment_tx_output_idx, option),
477         },
478         (1, MaturingOutput) => {
479                 (0, descriptor, required),
480         },
481         (3, FundingSpendConfirmation) => {
482                 (0, on_local_output_csv, option),
483                 (1, commitment_tx_to_counterparty_output, option),
484         },
485         (5, HTLCSpendConfirmation) => {
486                 (0, commitment_tx_output_idx, required),
487                 (2, preimage, option),
488                 (4, on_to_local_output_csv, option),
489         },
490
491 );
492
493 #[derive(Clone, PartialEq, Eq)]
494 pub(crate) enum ChannelMonitorUpdateStep {
495         LatestHolderCommitmentTXInfo {
496                 commitment_tx: HolderCommitmentTransaction,
497                 /// Note that LDK after 0.0.115 supports this only containing dust HTLCs (implying the
498                 /// `Signature` field is never filled in). At that point, non-dust HTLCs are implied by the
499                 /// HTLC fields in `commitment_tx` and the sources passed via `nondust_htlc_sources`.
500                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
501                 claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
502                 nondust_htlc_sources: Vec<HTLCSource>,
503         },
504         LatestCounterpartyCommitmentTXInfo {
505                 commitment_txid: Txid,
506                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
507                 commitment_number: u64,
508                 their_per_commitment_point: PublicKey,
509         },
510         PaymentPreimage {
511                 payment_preimage: PaymentPreimage,
512         },
513         CommitmentSecret {
514                 idx: u64,
515                 secret: [u8; 32],
516         },
517         /// Used to indicate that the no future updates will occur, and likely that the latest holder
518         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
519         ChannelForceClosed {
520                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
521                 /// think we've fallen behind!
522                 should_broadcast: bool,
523         },
524         ShutdownScript {
525                 scriptpubkey: Script,
526         },
527 }
528
529 impl ChannelMonitorUpdateStep {
530         fn variant_name(&self) -> &'static str {
531                 match self {
532                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
533                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
534                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
535                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
536                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
537                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
538                 }
539         }
540 }
541
542 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
543         (0, LatestHolderCommitmentTXInfo) => {
544                 (0, commitment_tx, required),
545                 (1, claimed_htlcs, vec_type),
546                 (2, htlc_outputs, vec_type),
547                 (4, nondust_htlc_sources, optional_vec),
548         },
549         (1, LatestCounterpartyCommitmentTXInfo) => {
550                 (0, commitment_txid, required),
551                 (2, commitment_number, required),
552                 (4, their_per_commitment_point, required),
553                 (6, htlc_outputs, vec_type),
554         },
555         (2, PaymentPreimage) => {
556                 (0, payment_preimage, required),
557         },
558         (3, CommitmentSecret) => {
559                 (0, idx, required),
560                 (2, secret, required),
561         },
562         (4, ChannelForceClosed) => {
563                 (0, should_broadcast, required),
564         },
565         (5, ShutdownScript) => {
566                 (0, scriptpubkey, required),
567         },
568 );
569
570 /// Details about the balance(s) available for spending once the channel appears on chain.
571 ///
572 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
573 /// be provided.
574 #[derive(Clone, Debug, PartialEq, Eq)]
575 #[cfg_attr(test, derive(PartialOrd, Ord))]
576 pub enum Balance {
577         /// The channel is not yet closed (or the commitment or closing transaction has not yet
578         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
579         /// force-closed now.
580         ClaimableOnChannelClose {
581                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
582                 /// required to do so.
583                 claimable_amount_satoshis: u64,
584         },
585         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
586         /// we consider it spendable.
587         ClaimableAwaitingConfirmations {
588                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
589                 /// were spent in broadcasting the transaction.
590                 claimable_amount_satoshis: u64,
591                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
592                 /// amount.
593                 confirmation_height: u32,
594         },
595         /// The channel has been closed, and the given balance should be ours but awaiting spending
596         /// transaction confirmation. If the spending transaction does not confirm in time, it is
597         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
598         ///
599         /// Once the spending transaction confirms, before it has reached enough confirmations to be
600         /// considered safe from chain reorganizations, the balance will instead be provided via
601         /// [`Balance::ClaimableAwaitingConfirmations`].
602         ContentiousClaimable {
603                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
604                 /// required to do so.
605                 claimable_amount_satoshis: u64,
606                 /// The height at which the counterparty may be able to claim the balance if we have not
607                 /// done so.
608                 timeout_height: u32,
609                 /// The payment hash that locks this HTLC.
610                 payment_hash: PaymentHash,
611                 /// The preimage that can be used to claim this HTLC.
612                 payment_preimage: PaymentPreimage,
613         },
614         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
615         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
616         /// likely to be claimed by our counterparty before we do.
617         MaybeTimeoutClaimableHTLC {
618                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
619                 /// which will be required to do so.
620                 claimable_amount_satoshis: u64,
621                 /// The height at which we will be able to claim the balance if our counterparty has not
622                 /// done so.
623                 claimable_height: u32,
624                 /// The payment hash whose preimage our counterparty needs to claim this HTLC.
625                 payment_hash: PaymentHash,
626         },
627         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
628         /// do not currently have. This will only be claimable if we receive the preimage from the node
629         /// to which we forwarded this HTLC before the timeout.
630         MaybePreimageClaimableHTLC {
631                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
632                 /// which will be required to do so.
633                 claimable_amount_satoshis: u64,
634                 /// The height at which our counterparty will be able to claim the balance if we have not
635                 /// yet received the preimage and claimed it ourselves.
636                 expiry_height: u32,
637                 /// The payment hash whose preimage we need to claim this HTLC.
638                 payment_hash: PaymentHash,
639         },
640         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
641         /// transaction.
642         ///
643         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
644         /// following amount.
645         CounterpartyRevokedOutputClaimable {
646                 /// The amount, in satoshis, of the output which we can claim.
647                 ///
648                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
649                 /// were already spent.
650                 claimable_amount_satoshis: u64,
651         },
652 }
653
654 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
655 #[derive(PartialEq, Eq)]
656 struct IrrevocablyResolvedHTLC {
657         commitment_tx_output_idx: Option<u32>,
658         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
659         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
660         /// transaction.
661         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
662         resolving_tx: Option<Transaction>,
663         /// Only set if the HTLC claim was ours using a payment preimage
664         payment_preimage: Option<PaymentPreimage>,
665 }
666
667 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
668 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
669 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
670 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
671 impl Writeable for IrrevocablyResolvedHTLC {
672         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
673                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
674                 write_tlv_fields!(writer, {
675                         (0, mapped_commitment_tx_output_idx, required),
676                         (1, self.resolving_txid, option),
677                         (2, self.payment_preimage, option),
678                         (3, self.resolving_tx, option),
679                 });
680                 Ok(())
681         }
682 }
683
684 impl Readable for IrrevocablyResolvedHTLC {
685         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
686                 let mut mapped_commitment_tx_output_idx = 0;
687                 let mut resolving_txid = None;
688                 let mut payment_preimage = None;
689                 let mut resolving_tx = None;
690                 read_tlv_fields!(reader, {
691                         (0, mapped_commitment_tx_output_idx, required),
692                         (1, resolving_txid, option),
693                         (2, payment_preimage, option),
694                         (3, resolving_tx, option),
695                 });
696                 Ok(Self {
697                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
698                         resolving_txid,
699                         payment_preimage,
700                         resolving_tx,
701                 })
702         }
703 }
704
705 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
706 /// on-chain transactions to ensure no loss of funds occurs.
707 ///
708 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
709 /// information and are actively monitoring the chain.
710 ///
711 /// Pending Events or updated HTLCs which have not yet been read out by
712 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
713 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
714 /// gotten are fully handled before re-serializing the new state.
715 ///
716 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
717 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
718 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
719 /// returned block hash and the the current chain and then reconnecting blocks to get to the
720 /// best chain) upon deserializing the object!
721 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
722         #[cfg(test)]
723         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
724         #[cfg(not(test))]
725         inner: Mutex<ChannelMonitorImpl<Signer>>,
726 }
727
728 #[derive(PartialEq)]
729 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
730         latest_update_id: u64,
731         commitment_transaction_number_obscure_factor: u64,
732
733         destination_script: Script,
734         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
735         counterparty_payment_script: Script,
736         shutdown_script: Option<Script>,
737
738         channel_keys_id: [u8; 32],
739         holder_revocation_basepoint: PublicKey,
740         funding_info: (OutPoint, Script),
741         current_counterparty_commitment_txid: Option<Txid>,
742         prev_counterparty_commitment_txid: Option<Txid>,
743
744         counterparty_commitment_params: CounterpartyCommitmentParameters,
745         funding_redeemscript: Script,
746         channel_value_satoshis: u64,
747         // first is the idx of the first of the two per-commitment points
748         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
749
750         on_holder_tx_csv: u16,
751
752         commitment_secrets: CounterpartyCommitmentSecrets,
753         /// The set of outpoints in each counterparty commitment transaction. We always need at least
754         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
755         /// transaction broadcast as we need to be able to construct the witness script in all cases.
756         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
757         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
758         /// Nor can we figure out their commitment numbers without the commitment transaction they are
759         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
760         /// commitment transactions which we find on-chain, mapping them to the commitment number which
761         /// can be used to derive the revocation key and claim the transactions.
762         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
763         /// Cache used to make pruning of payment_preimages faster.
764         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
765         /// counterparty transactions (ie should remain pretty small).
766         /// Serialized to disk but should generally not be sent to Watchtowers.
767         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
768
769         counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
770
771         // We store two holder commitment transactions to avoid any race conditions where we may update
772         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
773         // various monitors for one channel being out of sync, and us broadcasting a holder
774         // transaction for which we have deleted claim information on some watchtowers.
775         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
776         current_holder_commitment_tx: HolderSignedTx,
777
778         // Used just for ChannelManager to make sure it has the latest channel data during
779         // deserialization
780         current_counterparty_commitment_number: u64,
781         // Used just for ChannelManager to make sure it has the latest channel data during
782         // deserialization
783         current_holder_commitment_number: u64,
784
785         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
786         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
787         /// remote commitment transactions are automatically removed when commitment transactions are
788         /// revoked.
789         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
790
791         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
792         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
793         // presumably user implementations thereof as well) where we update the in-memory channel
794         // object, then before the persistence finishes (as it's all under a read-lock), we return
795         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
796         // the pre-event state here, but have processed the event in the `ChannelManager`.
797         // Note that because the `event_lock` in `ChainMonitor` is only taken in
798         // block/transaction-connected events and *not* during block/transaction-disconnected events,
799         // we further MUST NOT generate events during block/transaction-disconnection.
800         pending_monitor_events: Vec<MonitorEvent>,
801
802         pending_events: Vec<Event>,
803
804         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
805         // which to take actions once they reach enough confirmations. Each entry includes the
806         // transaction's id and the height when the transaction was confirmed on chain.
807         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
808
809         // If we get serialized out and re-read, we need to make sure that the chain monitoring
810         // interface knows about the TXOs that we want to be notified of spends of. We could probably
811         // be smart and derive them from the above storage fields, but its much simpler and more
812         // Obviously Correct (tm) if we just keep track of them explicitly.
813         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
814
815         #[cfg(test)]
816         pub onchain_tx_handler: OnchainTxHandler<Signer>,
817         #[cfg(not(test))]
818         onchain_tx_handler: OnchainTxHandler<Signer>,
819
820         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
821         // channel has been force-closed. After this is set, no further holder commitment transaction
822         // updates may occur, and we panic!() if one is provided.
823         lockdown_from_offchain: bool,
824
825         // Set once we've signed a holder commitment transaction and handed it over to our
826         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
827         // may occur, and we fail any such monitor updates.
828         //
829         // In case of update rejection due to a locally already signed commitment transaction, we
830         // nevertheless store update content to track in case of concurrent broadcast by another
831         // remote monitor out-of-order with regards to the block view.
832         holder_tx_signed: bool,
833
834         // If a spend of the funding output is seen, we set this to true and reject any further
835         // updates. This prevents any further changes in the offchain state no matter the order
836         // of block connection between ChannelMonitors and the ChannelManager.
837         funding_spend_seen: bool,
838
839         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
840         /// reaching `ANTI_REORG_DELAY` confirmations.
841         funding_spend_confirmed: Option<Txid>,
842
843         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
844         /// The set of HTLCs which have been either claimed or failed on chain and have reached
845         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
846         /// spending CSV for revocable outputs).
847         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
848
849         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
850         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
851         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
852         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
853         /// [`ANTI_REORG_DELAY`], so we have to track them here.
854         spendable_txids_confirmed: Vec<Txid>,
855
856         // We simply modify best_block in Channel's block_connected so that serialization is
857         // consistent but hopefully the users' copy handles block_connected in a consistent way.
858         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
859         // their best_block from its state and not based on updated copies that didn't run through
860         // the full block_connected).
861         best_block: BestBlock,
862
863         /// The node_id of our counterparty
864         counterparty_node_id: Option<PublicKey>,
865 }
866
867 /// Transaction outputs to watch for on-chain spends.
868 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
869
870 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
871         fn eq(&self, other: &Self) -> bool {
872                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
873                 // memory and take locks in that order (assuming that we can't move within memory while a
874                 // lock is held).
875                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
876                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
877                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
878                 a.eq(&b)
879         }
880 }
881
882 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
883         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
884                 self.inner.lock().unwrap().write(writer)
885         }
886 }
887
888 // These are also used for ChannelMonitorUpdate, above.
889 const SERIALIZATION_VERSION: u8 = 1;
890 const MIN_SERIALIZATION_VERSION: u8 = 1;
891
892 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
893         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
894                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
895
896                 self.latest_update_id.write(writer)?;
897
898                 // Set in initial Channel-object creation, so should always be set by now:
899                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
900
901                 self.destination_script.write(writer)?;
902                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
903                         writer.write_all(&[0; 1])?;
904                         broadcasted_holder_revokable_script.0.write(writer)?;
905                         broadcasted_holder_revokable_script.1.write(writer)?;
906                         broadcasted_holder_revokable_script.2.write(writer)?;
907                 } else {
908                         writer.write_all(&[1; 1])?;
909                 }
910
911                 self.counterparty_payment_script.write(writer)?;
912                 match &self.shutdown_script {
913                         Some(script) => script.write(writer)?,
914                         None => Script::new().write(writer)?,
915                 }
916
917                 self.channel_keys_id.write(writer)?;
918                 self.holder_revocation_basepoint.write(writer)?;
919                 writer.write_all(&self.funding_info.0.txid[..])?;
920                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
921                 self.funding_info.1.write(writer)?;
922                 self.current_counterparty_commitment_txid.write(writer)?;
923                 self.prev_counterparty_commitment_txid.write(writer)?;
924
925                 self.counterparty_commitment_params.write(writer)?;
926                 self.funding_redeemscript.write(writer)?;
927                 self.channel_value_satoshis.write(writer)?;
928
929                 match self.their_cur_per_commitment_points {
930                         Some((idx, pubkey, second_option)) => {
931                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
932                                 writer.write_all(&pubkey.serialize())?;
933                                 match second_option {
934                                         Some(second_pubkey) => {
935                                                 writer.write_all(&second_pubkey.serialize())?;
936                                         },
937                                         None => {
938                                                 writer.write_all(&[0; 33])?;
939                                         },
940                                 }
941                         },
942                         None => {
943                                 writer.write_all(&byte_utils::be48_to_array(0))?;
944                         },
945                 }
946
947                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
948
949                 self.commitment_secrets.write(writer)?;
950
951                 macro_rules! serialize_htlc_in_commitment {
952                         ($htlc_output: expr) => {
953                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
954                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
955                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
956                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
957                                 $htlc_output.transaction_output_index.write(writer)?;
958                         }
959                 }
960
961                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
962                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
963                         writer.write_all(&txid[..])?;
964                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
965                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
966                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
967                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
968                                         "HTLC Sources for all revoked commitment transactions should be none!");
969                                 serialize_htlc_in_commitment!(htlc_output);
970                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
971                         }
972                 }
973
974                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
975                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
976                         writer.write_all(&txid[..])?;
977                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
978                 }
979
980                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
981                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
982                         writer.write_all(&payment_hash.0[..])?;
983                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
984                 }
985
986                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
987                         writer.write_all(&[1; 1])?;
988                         prev_holder_tx.write(writer)?;
989                 } else {
990                         writer.write_all(&[0; 1])?;
991                 }
992
993                 self.current_holder_commitment_tx.write(writer)?;
994
995                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
996                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
997
998                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
999                 for payment_preimage in self.payment_preimages.values() {
1000                         writer.write_all(&payment_preimage.0[..])?;
1001                 }
1002
1003                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
1004                         MonitorEvent::HTLCEvent(_) => true,
1005                         MonitorEvent::CommitmentTxConfirmed(_) => true,
1006                         _ => false,
1007                 }).count() as u64).to_be_bytes())?;
1008                 for event in self.pending_monitor_events.iter() {
1009                         match event {
1010                                 MonitorEvent::HTLCEvent(upd) => {
1011                                         0u8.write(writer)?;
1012                                         upd.write(writer)?;
1013                                 },
1014                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
1015                                 _ => {}, // Covered in the TLV writes below
1016                         }
1017                 }
1018
1019                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1020                 for event in self.pending_events.iter() {
1021                         event.write(writer)?;
1022                 }
1023
1024                 self.best_block.block_hash().write(writer)?;
1025                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1026
1027                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1028                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1029                         entry.write(writer)?;
1030                 }
1031
1032                 (self.outputs_to_watch.len() as u64).write(writer)?;
1033                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1034                         txid.write(writer)?;
1035                         (idx_scripts.len() as u64).write(writer)?;
1036                         for (idx, script) in idx_scripts.iter() {
1037                                 idx.write(writer)?;
1038                                 script.write(writer)?;
1039                         }
1040                 }
1041                 self.onchain_tx_handler.write(writer)?;
1042
1043                 self.lockdown_from_offchain.write(writer)?;
1044                 self.holder_tx_signed.write(writer)?;
1045
1046                 write_tlv_fields!(writer, {
1047                         (1, self.funding_spend_confirmed, option),
1048                         (3, self.htlcs_resolved_on_chain, vec_type),
1049                         (5, self.pending_monitor_events, vec_type),
1050                         (7, self.funding_spend_seen, required),
1051                         (9, self.counterparty_node_id, option),
1052                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1053                         (13, self.spendable_txids_confirmed, vec_type),
1054                         (15, self.counterparty_fulfilled_htlcs, required),
1055                 });
1056
1057                 Ok(())
1058         }
1059 }
1060
1061 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1062         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1063         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1064         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1065         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1066                 ChannelMonitor { inner: Mutex::new(imp) }
1067         }
1068
1069         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1070                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1071                           channel_parameters: &ChannelTransactionParameters,
1072                           funding_redeemscript: Script, channel_value_satoshis: u64,
1073                           commitment_transaction_number_obscure_factor: u64,
1074                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1075                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1076
1077                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1078                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1079                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1080
1081                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1082                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1083                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1084                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1085
1086                 let channel_keys_id = keys.channel_keys_id();
1087                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1088
1089                 // block for Rust 1.34 compat
1090                 let (holder_commitment_tx, current_holder_commitment_number) = {
1091                         let trusted_tx = initial_holder_commitment_tx.trust();
1092                         let txid = trusted_tx.txid();
1093
1094                         let tx_keys = trusted_tx.keys();
1095                         let holder_commitment_tx = HolderSignedTx {
1096                                 txid,
1097                                 revocation_key: tx_keys.revocation_key,
1098                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1099                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1100                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1101                                 per_commitment_point: tx_keys.per_commitment_point,
1102                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1103                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1104                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1105                         };
1106                         (holder_commitment_tx, trusted_tx.commitment_number())
1107                 };
1108
1109                 let onchain_tx_handler =
1110                         OnchainTxHandler::new(destination_script.clone(), keys,
1111                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1112
1113                 let mut outputs_to_watch = HashMap::new();
1114                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1115
1116                 Self::from_impl(ChannelMonitorImpl {
1117                         latest_update_id: 0,
1118                         commitment_transaction_number_obscure_factor,
1119
1120                         destination_script: destination_script.clone(),
1121                         broadcasted_holder_revokable_script: None,
1122                         counterparty_payment_script,
1123                         shutdown_script,
1124
1125                         channel_keys_id,
1126                         holder_revocation_basepoint,
1127                         funding_info,
1128                         current_counterparty_commitment_txid: None,
1129                         prev_counterparty_commitment_txid: None,
1130
1131                         counterparty_commitment_params,
1132                         funding_redeemscript,
1133                         channel_value_satoshis,
1134                         their_cur_per_commitment_points: None,
1135
1136                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1137
1138                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1139                         counterparty_claimable_outpoints: HashMap::new(),
1140                         counterparty_commitment_txn_on_chain: HashMap::new(),
1141                         counterparty_hash_commitment_number: HashMap::new(),
1142                         counterparty_fulfilled_htlcs: HashMap::new(),
1143
1144                         prev_holder_signed_commitment_tx: None,
1145                         current_holder_commitment_tx: holder_commitment_tx,
1146                         current_counterparty_commitment_number: 1 << 48,
1147                         current_holder_commitment_number,
1148
1149                         payment_preimages: HashMap::new(),
1150                         pending_monitor_events: Vec::new(),
1151                         pending_events: Vec::new(),
1152
1153                         onchain_events_awaiting_threshold_conf: Vec::new(),
1154                         outputs_to_watch,
1155
1156                         onchain_tx_handler,
1157
1158                         lockdown_from_offchain: false,
1159                         holder_tx_signed: false,
1160                         funding_spend_seen: false,
1161                         funding_spend_confirmed: None,
1162                         confirmed_commitment_tx_counterparty_output: None,
1163                         htlcs_resolved_on_chain: Vec::new(),
1164                         spendable_txids_confirmed: Vec::new(),
1165
1166                         best_block,
1167                         counterparty_node_id: Some(counterparty_node_id),
1168                 })
1169         }
1170
1171         #[cfg(test)]
1172         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1173                 self.inner.lock().unwrap().provide_secret(idx, secret)
1174         }
1175
1176         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1177         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1178         /// possibly future revocation/preimage information) to claim outputs where possible.
1179         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1180         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1181                 &self,
1182                 txid: Txid,
1183                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1184                 commitment_number: u64,
1185                 their_per_commitment_point: PublicKey,
1186                 logger: &L,
1187         ) where L::Target: Logger {
1188                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1189                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1190         }
1191
1192         #[cfg(test)]
1193         fn provide_latest_holder_commitment_tx(
1194                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1195                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1196         ) -> Result<(), ()> {
1197                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new(), Vec::new()).map_err(|_| ())
1198         }
1199
1200         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1201         /// off-chain state with a new commitment transaction.
1202         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1203                 &self,
1204                 payment_hash: &PaymentHash,
1205                 payment_preimage: &PaymentPreimage,
1206                 broadcaster: &B,
1207                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1208                 logger: &L,
1209         ) where
1210                 B::Target: BroadcasterInterface,
1211                 F::Target: FeeEstimator,
1212                 L::Target: Logger,
1213         {
1214                 self.inner.lock().unwrap().provide_payment_preimage(
1215                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1216         }
1217
1218         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1219         /// itself.
1220         ///
1221         /// panics if the given update is not the next update by update_id.
1222         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1223                 &self,
1224                 updates: &ChannelMonitorUpdate,
1225                 broadcaster: &B,
1226                 fee_estimator: F,
1227                 logger: &L,
1228         ) -> Result<(), ()>
1229         where
1230                 B::Target: BroadcasterInterface,
1231                 F::Target: FeeEstimator,
1232                 L::Target: Logger,
1233         {
1234                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1235         }
1236
1237         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1238         /// ChannelMonitor.
1239         pub fn get_latest_update_id(&self) -> u64 {
1240                 self.inner.lock().unwrap().get_latest_update_id()
1241         }
1242
1243         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1244         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1245                 self.inner.lock().unwrap().get_funding_txo().clone()
1246         }
1247
1248         /// Gets a list of txids, with their output scripts (in the order they appear in the
1249         /// transaction), which we must learn about spends of via block_connected().
1250         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1251                 self.inner.lock().unwrap().get_outputs_to_watch()
1252                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1253         }
1254
1255         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1256         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1257         /// have been registered.
1258         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1259                 let lock = self.inner.lock().unwrap();
1260                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1261                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1262                         for (index, script_pubkey) in outputs.iter() {
1263                                 assert!(*index <= u16::max_value() as u32);
1264                                 filter.register_output(WatchedOutput {
1265                                         block_hash: None,
1266                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1267                                         script_pubkey: script_pubkey.clone(),
1268                                 });
1269                         }
1270                 }
1271         }
1272
1273         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1274         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1275         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1276                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1277         }
1278
1279         /// Gets the list of pending events which were generated by previous actions, clearing the list
1280         /// in the process.
1281         ///
1282         /// This is called by the [`EventsProvider::process_pending_events`] implementation for
1283         /// [`ChainMonitor`].
1284         ///
1285         /// [`EventsProvider::process_pending_events`]: crate::events::EventsProvider::process_pending_events
1286         /// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor
1287         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1288                 self.inner.lock().unwrap().get_and_clear_pending_events()
1289         }
1290
1291         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1292                 self.inner.lock().unwrap().get_min_seen_secret()
1293         }
1294
1295         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1296                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1297         }
1298
1299         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1300                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1301         }
1302
1303         /// Gets the `node_id` of the counterparty for this channel.
1304         ///
1305         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1306         /// otherwise.
1307         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1308                 self.inner.lock().unwrap().counterparty_node_id
1309         }
1310
1311         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1312         /// the Channel was out-of-date.
1313         ///
1314         /// You may also use this to broadcast the latest local commitment transaction, either because
1315         /// a monitor update failed with [`ChannelMonitorUpdateStatus::PermanentFailure`] or because we've
1316         /// fallen behind (i.e. we've received proof that our counterparty side knows a revocation
1317         /// secret we gave them that they shouldn't know).
1318         ///
1319         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1320         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1321         /// close channel with their commitment transaction after a substantial amount of time. Best
1322         /// may be to contact the other node operator out-of-band to coordinate other options available
1323         /// to you. In any-case, the choice is up to you.
1324         ///
1325         /// [`ChannelMonitorUpdateStatus::PermanentFailure`]: super::ChannelMonitorUpdateStatus::PermanentFailure
1326         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1327         where L::Target: Logger {
1328                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1329         }
1330
1331         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1332         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1333         /// revoked commitment transaction.
1334         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1335         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1336         where L::Target: Logger {
1337                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1338         }
1339
1340         /// Processes transactions in a newly connected block, which may result in any of the following:
1341         /// - update the monitor's state against resolved HTLCs
1342         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1343         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1344         /// - detect settled outputs for later spending
1345         /// - schedule and bump any in-flight claims
1346         ///
1347         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1348         /// [`get_outputs_to_watch`].
1349         ///
1350         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1351         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1352                 &self,
1353                 header: &BlockHeader,
1354                 txdata: &TransactionData,
1355                 height: u32,
1356                 broadcaster: B,
1357                 fee_estimator: F,
1358                 logger: L,
1359         ) -> Vec<TransactionOutputs>
1360         where
1361                 B::Target: BroadcasterInterface,
1362                 F::Target: FeeEstimator,
1363                 L::Target: Logger,
1364         {
1365                 self.inner.lock().unwrap().block_connected(
1366                         header, txdata, height, broadcaster, fee_estimator, logger)
1367         }
1368
1369         /// Determines if the disconnected block contained any transactions of interest and updates
1370         /// appropriately.
1371         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1372                 &self,
1373                 header: &BlockHeader,
1374                 height: u32,
1375                 broadcaster: B,
1376                 fee_estimator: F,
1377                 logger: L,
1378         ) where
1379                 B::Target: BroadcasterInterface,
1380                 F::Target: FeeEstimator,
1381                 L::Target: Logger,
1382         {
1383                 self.inner.lock().unwrap().block_disconnected(
1384                         header, height, broadcaster, fee_estimator, logger)
1385         }
1386
1387         /// Processes transactions confirmed in a block with the given header and height, returning new
1388         /// outputs to watch. See [`block_connected`] for details.
1389         ///
1390         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1391         /// blocks. See [`chain::Confirm`] for calling expectations.
1392         ///
1393         /// [`block_connected`]: Self::block_connected
1394         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1395                 &self,
1396                 header: &BlockHeader,
1397                 txdata: &TransactionData,
1398                 height: u32,
1399                 broadcaster: B,
1400                 fee_estimator: F,
1401                 logger: L,
1402         ) -> Vec<TransactionOutputs>
1403         where
1404                 B::Target: BroadcasterInterface,
1405                 F::Target: FeeEstimator,
1406                 L::Target: Logger,
1407         {
1408                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1409                 self.inner.lock().unwrap().transactions_confirmed(
1410                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1411         }
1412
1413         /// Processes a transaction that was reorganized out of the chain.
1414         ///
1415         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1416         /// than blocks. See [`chain::Confirm`] for calling expectations.
1417         ///
1418         /// [`block_disconnected`]: Self::block_disconnected
1419         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1420                 &self,
1421                 txid: &Txid,
1422                 broadcaster: B,
1423                 fee_estimator: F,
1424                 logger: L,
1425         ) where
1426                 B::Target: BroadcasterInterface,
1427                 F::Target: FeeEstimator,
1428                 L::Target: Logger,
1429         {
1430                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1431                 self.inner.lock().unwrap().transaction_unconfirmed(
1432                         txid, broadcaster, &bounded_fee_estimator, logger);
1433         }
1434
1435         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1436         /// [`block_connected`] for details.
1437         ///
1438         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1439         /// blocks. See [`chain::Confirm`] for calling expectations.
1440         ///
1441         /// [`block_connected`]: Self::block_connected
1442         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1443                 &self,
1444                 header: &BlockHeader,
1445                 height: u32,
1446                 broadcaster: B,
1447                 fee_estimator: F,
1448                 logger: L,
1449         ) -> Vec<TransactionOutputs>
1450         where
1451                 B::Target: BroadcasterInterface,
1452                 F::Target: FeeEstimator,
1453                 L::Target: Logger,
1454         {
1455                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1456                 self.inner.lock().unwrap().best_block_updated(
1457                         header, height, broadcaster, &bounded_fee_estimator, logger)
1458         }
1459
1460         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1461         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1462                 let inner = self.inner.lock().unwrap();
1463                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1464                         .iter()
1465                         .map(|entry| (entry.txid, entry.block_hash))
1466                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1467                         .collect();
1468                 txids.sort_unstable();
1469                 txids.dedup();
1470                 txids
1471         }
1472
1473         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1474         /// [`chain::Confirm`] interfaces.
1475         pub fn current_best_block(&self) -> BestBlock {
1476                 self.inner.lock().unwrap().best_block.clone()
1477         }
1478
1479         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
1480         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
1481         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
1482         /// invoking this every 30 seconds, or lower if running in an environment with spotty
1483         /// connections, like on mobile.
1484         pub fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
1485                 &self, broadcaster: B, fee_estimator: F, logger: L,
1486         )
1487         where
1488                 B::Target: BroadcasterInterface,
1489                 F::Target: FeeEstimator,
1490                 L::Target: Logger,
1491         {
1492                 let fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1493                 let mut inner = self.inner.lock().unwrap();
1494                 let current_height = inner.best_block.height;
1495                 inner.onchain_tx_handler.rebroadcast_pending_claims(
1496                         current_height, &broadcaster, &fee_estimator, &logger,
1497                 );
1498         }
1499 }
1500
1501 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1502         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1503         /// to one `Balance` for the HTLC.
1504         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1505                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1506         -> Option<Balance> {
1507                 let htlc_commitment_tx_output_idx =
1508                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1509
1510                 let mut htlc_spend_txid_opt = None;
1511                 let mut htlc_spend_tx_opt = None;
1512                 let mut holder_timeout_spend_pending = None;
1513                 let mut htlc_spend_pending = None;
1514                 let mut holder_delayed_output_pending = None;
1515                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1516                         match event.event {
1517                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1518                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1519                                         debug_assert!(htlc_spend_txid_opt.is_none());
1520                                         htlc_spend_txid_opt = Some(&event.txid);
1521                                         debug_assert!(htlc_spend_tx_opt.is_none());
1522                                         htlc_spend_tx_opt = event.transaction.as_ref();
1523                                         debug_assert!(holder_timeout_spend_pending.is_none());
1524                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1525                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1526                                 },
1527                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1528                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1529                                         debug_assert!(htlc_spend_txid_opt.is_none());
1530                                         htlc_spend_txid_opt = Some(&event.txid);
1531                                         debug_assert!(htlc_spend_tx_opt.is_none());
1532                                         htlc_spend_tx_opt = event.transaction.as_ref();
1533                                         debug_assert!(htlc_spend_pending.is_none());
1534                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1535                                 },
1536                                 OnchainEvent::MaturingOutput {
1537                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1538                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1539                                         debug_assert!(holder_delayed_output_pending.is_none());
1540                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1541                                 },
1542                                 _ => {},
1543                         }
1544                 }
1545                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1546                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1547                                 debug_assert!(htlc_spend_txid_opt.is_none());
1548                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1549                                 debug_assert!(htlc_spend_tx_opt.is_none());
1550                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1551                                 true
1552                         } else { false });
1553                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1554
1555                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1556                 let htlc_output_to_spend =
1557                         if let Some(txid) = htlc_spend_txid_opt {
1558                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1559                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1560                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1561                                 // in the commitment.
1562                                 if let Some(ref tx) = htlc_spend_tx_opt {
1563                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1564                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1565                                                 .map(|(idx, _)| idx as u32);
1566                                         debug_assert!(htlc_input_idx_opt.is_some());
1567                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1568                                 } else {
1569                                         debug_assert!(!self.onchain_tx_handler.opt_anchors());
1570                                         BitcoinOutPoint::new(*txid, 0)
1571                                 }
1572                         } else {
1573                                 htlc_commitment_outpoint
1574                         };
1575                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1576
1577                 if let Some(conf_thresh) = holder_delayed_output_pending {
1578                         debug_assert!(holder_commitment);
1579                         return Some(Balance::ClaimableAwaitingConfirmations {
1580                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1581                                 confirmation_height: conf_thresh,
1582                         });
1583                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1584                         // Funding transaction spends should be fully confirmed by the time any
1585                         // HTLC transactions are resolved, unless we're talking about a holder
1586                         // commitment tx, whose resolution is delayed until the CSV timeout is
1587                         // reached, even though HTLCs may be resolved after only
1588                         // ANTI_REORG_DELAY confirmations.
1589                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1590                 } else if counterparty_revoked_commitment {
1591                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1592                                 if let OnchainEvent::MaturingOutput {
1593                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1594                                 } = &event.event {
1595                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1596                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1597                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1598                                                 } else {
1599                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1600                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1601                                                 }
1602                                         })).unwrap_or(false) {
1603                                                 Some(())
1604                                         } else { None }
1605                                 } else { None }
1606                         });
1607                         if htlc_output_claim_pending.is_some() {
1608                                 // We already push `Balance`s onto the `res` list for every
1609                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1610                                 // counterparty commitment transaction case generally, so don't
1611                                 // need to do so again here.
1612                         } else {
1613                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1614                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1615                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1616                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1617                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1618                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1619                                 });
1620                         }
1621                 } else if htlc.offered == holder_commitment {
1622                         // If the payment was outbound, check if there's an HTLCUpdate
1623                         // indicating we have spent this HTLC with a timeout, claiming it back
1624                         // and awaiting confirmations on it.
1625                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1626                                 return Some(Balance::ClaimableAwaitingConfirmations {
1627                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1628                                         confirmation_height: conf_thresh,
1629                                 });
1630                         } else {
1631                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1632                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1633                                         claimable_height: htlc.cltv_expiry,
1634                                         payment_hash: htlc.payment_hash,
1635                                 });
1636                         }
1637                 } else if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1638                         // Otherwise (the payment was inbound), only expose it as claimable if
1639                         // we know the preimage.
1640                         // Note that if there is a pending claim, but it did not use the
1641                         // preimage, we lost funds to our counterparty! We will then continue
1642                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1643                         debug_assert!(holder_timeout_spend_pending.is_none());
1644                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1645                                 return Some(Balance::ClaimableAwaitingConfirmations {
1646                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1647                                         confirmation_height: conf_thresh,
1648                                 });
1649                         } else {
1650                                 return Some(Balance::ContentiousClaimable {
1651                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1652                                         timeout_height: htlc.cltv_expiry,
1653                                         payment_hash: htlc.payment_hash,
1654                                         payment_preimage: *payment_preimage,
1655                                 });
1656                         }
1657                 } else if htlc_resolved.is_none() {
1658                         return Some(Balance::MaybePreimageClaimableHTLC {
1659                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1660                                 expiry_height: htlc.cltv_expiry,
1661                                 payment_hash: htlc.payment_hash,
1662                         });
1663                 }
1664                 None
1665         }
1666 }
1667
1668 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1669         /// Gets the balances in this channel which are either claimable by us if we were to
1670         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1671         /// confirmation).
1672         ///
1673         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1674         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1675         /// balance, or until our counterparty has claimed the balance and accrued several
1676         /// confirmations on the claim transaction.
1677         ///
1678         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1679         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1680         /// a revoked state.
1681         ///
1682         /// See [`Balance`] for additional details on the types of claimable balances which
1683         /// may be returned here and their meanings.
1684         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1685                 let mut res = Vec::new();
1686                 let us = self.inner.lock().unwrap();
1687
1688                 let mut confirmed_txid = us.funding_spend_confirmed;
1689                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1690                 let mut pending_commitment_tx_conf_thresh = None;
1691                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1692                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1693                                 event.event
1694                         {
1695                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1696                                 Some((event.txid, event.confirmation_threshold()))
1697                         } else { None }
1698                 });
1699                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1700                         debug_assert!(us.funding_spend_confirmed.is_none(),
1701                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1702                         confirmed_txid = Some(txid);
1703                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1704                 }
1705
1706                 macro_rules! walk_htlcs {
1707                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1708                                 for htlc in $htlc_iter {
1709                                         if htlc.transaction_output_index.is_some() {
1710
1711                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1712                                                         res.push(bal);
1713                                                 }
1714                                         }
1715                                 }
1716                         }
1717                 }
1718
1719                 if let Some(txid) = confirmed_txid {
1720                         let mut found_commitment_tx = false;
1721                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1722                                 // First look for the to_remote output back to us.
1723                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1724                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1725                                                 if let OnchainEvent::MaturingOutput {
1726                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1727                                                 } = &event.event {
1728                                                         Some(descriptor.output.value)
1729                                                 } else { None }
1730                                         }) {
1731                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1732                                                         claimable_amount_satoshis: value,
1733                                                         confirmation_height: conf_thresh,
1734                                                 });
1735                                         } else {
1736                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1737                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1738                                                 // confirmation with the same height or have never met our dust amount.
1739                                         }
1740                                 }
1741                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1742                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1743                                 } else {
1744                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1745                                         // The counterparty broadcasted a revoked state!
1746                                         // Look for any StaticOutputs first, generating claimable balances for those.
1747                                         // If any match the confirmed counterparty revoked to_self output, skip
1748                                         // generating a CounterpartyRevokedOutputClaimable.
1749                                         let mut spent_counterparty_output = false;
1750                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1751                                                 if let OnchainEvent::MaturingOutput {
1752                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1753                                                 } = &event.event {
1754                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1755                                                                 claimable_amount_satoshis: output.value,
1756                                                                 confirmation_height: event.confirmation_threshold(),
1757                                                         });
1758                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1759                                                                 if event.transaction.as_ref().map(|tx|
1760                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1761                                                                 ).unwrap_or(false) {
1762                                                                         spent_counterparty_output = true;
1763                                                                 }
1764                                                         }
1765                                                 }
1766                                         }
1767
1768                                         if spent_counterparty_output {
1769                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1770                                                 let output_spendable = us.onchain_tx_handler
1771                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1772                                                 if output_spendable {
1773                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1774                                                                 claimable_amount_satoshis: amt,
1775                                                         });
1776                                                 }
1777                                         } else {
1778                                                 // Counterparty output is missing, either it was broadcasted on a
1779                                                 // previous version of LDK or the counterparty hadn't met dust.
1780                                         }
1781                                 }
1782                                 found_commitment_tx = true;
1783                         } else if txid == us.current_holder_commitment_tx.txid {
1784                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1785                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1786                                         res.push(Balance::ClaimableAwaitingConfirmations {
1787                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1788                                                 confirmation_height: conf_thresh,
1789                                         });
1790                                 }
1791                                 found_commitment_tx = true;
1792                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1793                                 if txid == prev_commitment.txid {
1794                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1795                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1796                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1797                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1798                                                         confirmation_height: conf_thresh,
1799                                                 });
1800                                         }
1801                                         found_commitment_tx = true;
1802                                 }
1803                         }
1804                         if !found_commitment_tx {
1805                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1806                                         // We blindly assume this is a cooperative close transaction here, and that
1807                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1808                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1809                                         res.push(Balance::ClaimableAwaitingConfirmations {
1810                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1811                                                 confirmation_height: conf_thresh,
1812                                         });
1813                                 }
1814                         }
1815                 } else {
1816                         let mut claimable_inbound_htlc_value_sat = 0;
1817                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1818                                 if htlc.transaction_output_index.is_none() { continue; }
1819                                 if htlc.offered {
1820                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
1821                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1822                                                 claimable_height: htlc.cltv_expiry,
1823                                                 payment_hash: htlc.payment_hash,
1824                                         });
1825                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1826                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1827                                 } else {
1828                                         // As long as the HTLC is still in our latest commitment state, treat
1829                                         // it as potentially claimable, even if it has long-since expired.
1830                                         res.push(Balance::MaybePreimageClaimableHTLC {
1831                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1832                                                 expiry_height: htlc.cltv_expiry,
1833                                                 payment_hash: htlc.payment_hash,
1834                                         });
1835                                 }
1836                         }
1837                         res.push(Balance::ClaimableOnChannelClose {
1838                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1839                         });
1840                 }
1841
1842                 res
1843         }
1844
1845         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
1846         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
1847         /// to the `ChannelManager` having been persisted.
1848         ///
1849         /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
1850         /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
1851         /// event from this `ChannelMonitor`).
1852         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1853                 let mut res = HashMap::new();
1854                 // Just examine the available counterparty commitment transactions. See docs on
1855                 // `fail_unbroadcast_htlcs`, below, for justification.
1856                 let us = self.inner.lock().unwrap();
1857                 macro_rules! walk_counterparty_commitment {
1858                         ($txid: expr) => {
1859                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1860                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1861                                                 if let &Some(ref source) = source_option {
1862                                                         res.insert((**source).clone(), (htlc.clone(),
1863                                                                 us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
1864                                                 }
1865                                         }
1866                                 }
1867                         }
1868                 }
1869                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
1870                         walk_counterparty_commitment!(txid);
1871                 }
1872                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1873                         walk_counterparty_commitment!(txid);
1874                 }
1875                 res
1876         }
1877
1878         /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
1879         /// resolved with a preimage from our counterparty.
1880         ///
1881         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1882         ///
1883         /// Currently, the preimage is unused, however if it is present in the relevant internal state
1884         /// an HTLC is always included even if it has been resolved.
1885         pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
1886                 let us = self.inner.lock().unwrap();
1887                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1888                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1889                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1890                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1891                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1892                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1893                                         Some(event.txid)
1894                                 } else { None }
1895                         })
1896                 });
1897
1898                 if confirmed_txid.is_none() {
1899                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1900                         // closed), just get the full set.
1901                         mem::drop(us);
1902                         return self.get_all_current_outbound_htlcs();
1903                 }
1904
1905                 let mut res = HashMap::new();
1906                 macro_rules! walk_htlcs {
1907                         ($holder_commitment: expr, $htlc_iter: expr) => {
1908                                 for (htlc, source) in $htlc_iter {
1909                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
1910                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1911                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1912                                                 // would fail.
1913                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1914                                                 // should assert here like we do in `get_claimable_balances`.
1915                                         } else if htlc.offered == $holder_commitment {
1916                                                 // If the payment was outbound, check if there's an HTLCUpdate
1917                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1918                                                 // and awaiting confirmations on it.
1919                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1920                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1921                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1922                                                                 // before considering it "no longer pending" - this matches when we
1923                                                                 // provide the ChannelManager an HTLC failure event.
1924                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1925                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1926                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1927                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1928                                                                 // immediately non-pending, matching when we provide ChannelManager
1929                                                                 // the preimage.
1930                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1931                                                         } else { false }
1932                                                 });
1933                                                 let counterparty_resolved_preimage_opt =
1934                                                         us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
1935                                                 if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
1936                                                         res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
1937                                                 }
1938                                         }
1939                                 }
1940                         }
1941                 }
1942
1943                 let txid = confirmed_txid.unwrap();
1944                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1945                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1946                                 if let &Some(ref source) = b {
1947                                         Some((a, &**source))
1948                                 } else { None }
1949                         }));
1950                 } else if txid == us.current_holder_commitment_tx.txid {
1951                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1952                                 if let Some(source) = c { Some((a, source)) } else { None }
1953                         }));
1954                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1955                         if txid == prev_commitment.txid {
1956                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1957                                         if let Some(source) = c { Some((a, source)) } else { None }
1958                                 }));
1959                         }
1960                 }
1961
1962                 res
1963         }
1964
1965         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1966                 self.inner.lock().unwrap().payment_preimages.clone()
1967         }
1968 }
1969
1970 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1971 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1972 /// after ANTI_REORG_DELAY blocks.
1973 ///
1974 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1975 /// are the commitment transactions which are generated by us. The off-chain state machine in
1976 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1977 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1978 /// included in a remote commitment transaction are failed back if they are not present in the
1979 /// broadcasted commitment transaction.
1980 ///
1981 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1982 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1983 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1984 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1985 macro_rules! fail_unbroadcast_htlcs {
1986         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
1987          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1988                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
1989
1990                 macro_rules! check_htlc_fails {
1991                         ($txid: expr, $commitment_tx: expr) => {
1992                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1993                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1994                                                 if let &Some(ref source) = source_option {
1995                                                         // Check if the HTLC is present in the commitment transaction that was
1996                                                         // broadcast, but not if it was below the dust limit, which we should
1997                                                         // fail backwards immediately as there is no way for us to learn the
1998                                                         // payment_preimage.
1999                                                         // Note that if the dust limit were allowed to change between
2000                                                         // commitment transactions we'd want to be check whether *any*
2001                                                         // broadcastable commitment transaction has the HTLC in it, but it
2002                                                         // cannot currently change after channel initialization, so we don't
2003                                                         // need to here.
2004                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
2005
2006                                                         let mut matched_htlc = false;
2007                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
2008                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
2009                                                                         (Some(&**source) == *broadcast_source ||
2010                                                                          (broadcast_source.is_none() &&
2011                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
2012                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
2013                                                                         matched_htlc = true;
2014                                                                         break;
2015                                                                 }
2016                                                         }
2017                                                         if matched_htlc { continue; }
2018                                                         if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
2019                                                                 continue;
2020                                                         }
2021                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
2022                                                                 if entry.height != $commitment_tx_conf_height { return true; }
2023                                                                 match entry.event {
2024                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
2025                                                                                 *update_source != **source
2026                                                                         },
2027                                                                         _ => true,
2028                                                                 }
2029                                                         });
2030                                                         let entry = OnchainEventEntry {
2031                                                                 txid: $commitment_txid_confirmed,
2032                                                                 transaction: Some($commitment_tx_confirmed.clone()),
2033                                                                 height: $commitment_tx_conf_height,
2034                                                                 block_hash: Some(*$commitment_tx_conf_hash),
2035                                                                 event: OnchainEvent::HTLCUpdate {
2036                                                                         source: (**source).clone(),
2037                                                                         payment_hash: htlc.payment_hash.clone(),
2038                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
2039                                                                         commitment_tx_output_idx: None,
2040                                                                 },
2041                                                         };
2042                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
2043                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
2044                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
2045                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
2046                                                 }
2047                                         }
2048                                 }
2049                         }
2050                 }
2051                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2052                         check_htlc_fails!(txid, "current");
2053                 }
2054                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2055                         check_htlc_fails!(txid, "previous");
2056                 }
2057         } }
2058 }
2059
2060 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2061 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2062 // in-line tests later.
2063
2064 #[cfg(test)]
2065 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2066         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2067         ret[131] = opcodes::all::OP_DROP.to_u8();
2068         ret[132] = opcodes::all::OP_DROP.to_u8();
2069         ret[133] = opcodes::all::OP_DROP.to_u8();
2070         ret[134] = opcodes::all::OP_DROP.to_u8();
2071         ret[135] = opcodes::OP_TRUE.to_u8();
2072         Vec::from(&ret[..])
2073 }
2074
2075 #[cfg(test)]
2076 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2077         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2078 }
2079
2080 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2081         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2082         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2083         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2084         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2085                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2086                         return Err("Previous secret did not match new one");
2087                 }
2088
2089                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2090                 // events for now-revoked/fulfilled HTLCs.
2091                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2092                         if self.current_counterparty_commitment_txid.unwrap() != txid {
2093                                 let cur_claimables = self.counterparty_claimable_outpoints.get(
2094                                         &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2095                                 for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2096                                         if let Some(source) = source_opt {
2097                                                 if !cur_claimables.iter()
2098                                                         .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
2099                                                 {
2100                                                         self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
2101                                                 }
2102                                         }
2103                                 }
2104                                 for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2105                                         *source_opt = None;
2106                                 }
2107                         } else {
2108                                 assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
2109                         }
2110                 }
2111
2112                 if !self.payment_preimages.is_empty() {
2113                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2114                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2115                         let min_idx = self.get_min_seen_secret();
2116                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2117
2118                         self.payment_preimages.retain(|&k, _| {
2119                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2120                                         if k == htlc.payment_hash {
2121                                                 return true
2122                                         }
2123                                 }
2124                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2125                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2126                                                 if k == htlc.payment_hash {
2127                                                         return true
2128                                                 }
2129                                         }
2130                                 }
2131                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2132                                         if *cn < min_idx {
2133                                                 return true
2134                                         }
2135                                         true
2136                                 } else { false };
2137                                 if contains {
2138                                         counterparty_hash_commitment_number.remove(&k);
2139                                 }
2140                                 false
2141                         });
2142                 }
2143
2144                 Ok(())
2145         }
2146
2147         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_per_commitment_point: PublicKey, logger: &L) where L::Target: Logger {
2148                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2149                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2150                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2151                 // timeouts)
2152                 for &(ref htlc, _) in &htlc_outputs {
2153                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2154                 }
2155
2156                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2157                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2158                 self.current_counterparty_commitment_txid = Some(txid);
2159                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2160                 self.current_counterparty_commitment_number = commitment_number;
2161                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2162                 match self.their_cur_per_commitment_points {
2163                         Some(old_points) => {
2164                                 if old_points.0 == commitment_number + 1 {
2165                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2166                                 } else if old_points.0 == commitment_number + 2 {
2167                                         if let Some(old_second_point) = old_points.2 {
2168                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2169                                         } else {
2170                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2171                                         }
2172                                 } else {
2173                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2174                                 }
2175                         },
2176                         None => {
2177                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2178                         }
2179                 }
2180                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2181                 for htlc in htlc_outputs {
2182                         if htlc.0.transaction_output_index.is_some() {
2183                                 htlcs.push(htlc.0);
2184                         }
2185                 }
2186         }
2187
2188         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2189         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2190         /// is important that any clones of this channel monitor (including remote clones) by kept
2191         /// up-to-date as our holder commitment transaction is updated.
2192         /// Panics if set_on_holder_tx_csv has never been called.
2193         fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, mut htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>, claimed_htlcs: &[(SentHTLCId, PaymentPreimage)], nondust_htlc_sources: Vec<HTLCSource>) -> Result<(), &'static str> {
2194                 if htlc_outputs.iter().any(|(_, s, _)| s.is_some()) {
2195                         // If we have non-dust HTLCs in htlc_outputs, ensure they match the HTLCs in the
2196                         // `holder_commitment_tx`. In the future, we'll no longer provide the redundant data
2197                         // and just pass in source data via `nondust_htlc_sources`.
2198                         debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.trust().htlcs().len());
2199                         for (a, b) in htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).map(|(h, _, _)| h).zip(holder_commitment_tx.trust().htlcs().iter()) {
2200                                 debug_assert_eq!(a, b);
2201                         }
2202                         debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.counterparty_htlc_sigs.len());
2203                         for (a, b) in htlc_outputs.iter().filter_map(|(_, s, _)| s.as_ref()).zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) {
2204                                 debug_assert_eq!(a, b);
2205                         }
2206                         debug_assert!(nondust_htlc_sources.is_empty());
2207                 } else {
2208                         // If we don't have any non-dust HTLCs in htlc_outputs, assume they were all passed via
2209                         // `nondust_htlc_sources`, building up the final htlc_outputs by combining
2210                         // `nondust_htlc_sources` and the `holder_commitment_tx`
2211                         #[cfg(debug_assertions)] {
2212                                 let mut prev = -1;
2213                                 for htlc in holder_commitment_tx.trust().htlcs().iter() {
2214                                         assert!(htlc.transaction_output_index.unwrap() as i32 > prev);
2215                                         prev = htlc.transaction_output_index.unwrap() as i32;
2216                                 }
2217                         }
2218                         debug_assert!(htlc_outputs.iter().all(|(htlc, _, _)| htlc.transaction_output_index.is_none()));
2219                         debug_assert!(htlc_outputs.iter().all(|(_, sig_opt, _)| sig_opt.is_none()));
2220                         debug_assert_eq!(holder_commitment_tx.trust().htlcs().len(), holder_commitment_tx.counterparty_htlc_sigs.len());
2221
2222                         let mut sources_iter = nondust_htlc_sources.into_iter();
2223
2224                         for (htlc, counterparty_sig) in holder_commitment_tx.trust().htlcs().iter()
2225                                 .zip(holder_commitment_tx.counterparty_htlc_sigs.iter())
2226                         {
2227                                 if htlc.offered {
2228                                         let source = sources_iter.next().expect("Non-dust HTLC sources didn't match commitment tx");
2229                                         #[cfg(debug_assertions)] {
2230                                                 assert!(source.possibly_matches_output(htlc));
2231                                         }
2232                                         htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), Some(source)));
2233                                 } else {
2234                                         htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), None));
2235                                 }
2236                         }
2237                         debug_assert!(sources_iter.next().is_none());
2238                 }
2239
2240                 let trusted_tx = holder_commitment_tx.trust();
2241                 let txid = trusted_tx.txid();
2242                 let tx_keys = trusted_tx.keys();
2243                 self.current_holder_commitment_number = trusted_tx.commitment_number();
2244                 let mut new_holder_commitment_tx = HolderSignedTx {
2245                         txid,
2246                         revocation_key: tx_keys.revocation_key,
2247                         a_htlc_key: tx_keys.broadcaster_htlc_key,
2248                         b_htlc_key: tx_keys.countersignatory_htlc_key,
2249                         delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2250                         per_commitment_point: tx_keys.per_commitment_point,
2251                         htlc_outputs,
2252                         to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2253                         feerate_per_kw: trusted_tx.feerate_per_kw(),
2254                 };
2255                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2256                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2257                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2258                 for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
2259                         #[cfg(debug_assertions)] {
2260                                 let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
2261                                                 &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2262                                 assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
2263                                         if let Some(source) = source_opt {
2264                                                 SentHTLCId::from_source(source) == *claimed_htlc_id
2265                                         } else { false }
2266                                 }));
2267                         }
2268                         self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
2269                 }
2270                 if self.holder_tx_signed {
2271                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2272                 }
2273                 Ok(())
2274         }
2275
2276         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2277         /// commitment_tx_infos which contain the payment hash have been revoked.
2278         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2279                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2280                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2281         where B::Target: BroadcasterInterface,
2282                     F::Target: FeeEstimator,
2283                     L::Target: Logger,
2284         {
2285                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2286
2287                 // If the channel is force closed, try to claim the output from this preimage.
2288                 // First check if a counterparty commitment transaction has been broadcasted:
2289                 macro_rules! claim_htlcs {
2290                         ($commitment_number: expr, $txid: expr) => {
2291                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2292                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2293                         }
2294                 }
2295                 if let Some(txid) = self.current_counterparty_commitment_txid {
2296                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2297                                 claim_htlcs!(*commitment_number, txid);
2298                                 return;
2299                         }
2300                 }
2301                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2302                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2303                                 claim_htlcs!(*commitment_number, txid);
2304                                 return;
2305                         }
2306                 }
2307
2308                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2309                 // claiming the HTLC output from each of the holder commitment transactions.
2310                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2311                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2312                 // holder commitment transactions.
2313                 if self.broadcasted_holder_revokable_script.is_some() {
2314                         // Assume that the broadcasted commitment transaction confirmed in the current best
2315                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2316                         // transactions.
2317                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2318                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2319                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2320                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2321                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2322                         }
2323                 }
2324         }
2325
2326         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2327                 where B::Target: BroadcasterInterface,
2328                                         L::Target: Logger,
2329         {
2330                 let commit_txs = self.get_latest_holder_commitment_txn(logger);
2331                 let mut txs = vec![];
2332                 for tx in commit_txs.iter() {
2333                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2334                         txs.push(tx);
2335                 }
2336                 broadcaster.broadcast_transactions(&txs);
2337                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2338         }
2339
2340         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2341         where B::Target: BroadcasterInterface,
2342                 F::Target: FeeEstimator,
2343                 L::Target: Logger,
2344         {
2345                 if self.latest_update_id == CLOSED_CHANNEL_UPDATE_ID && updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2346                         log_info!(logger, "Applying post-force-closed update to monitor {} with {} change(s).",
2347                                 log_funding_info!(self), updates.updates.len());
2348                 } else if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2349                         log_info!(logger, "Applying force close update to monitor {} with {} change(s).",
2350                                 log_funding_info!(self), updates.updates.len());
2351                 } else {
2352                         log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} change(s).",
2353                                 log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2354                 }
2355                 // ChannelMonitor updates may be applied after force close if we receive a preimage for a
2356                 // broadcasted commitment transaction HTLC output that we'd like to claim on-chain. If this
2357                 // is the case, we no longer have guaranteed access to the monitor's update ID, so we use a
2358                 // sentinel value instead.
2359                 //
2360                 // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still
2361                 // thinks the channel needs to have its commitment transaction broadcast, so we'll allow
2362                 // them as well.
2363                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2364                         assert_eq!(updates.updates.len(), 1);
2365                         match updates.updates[0] {
2366                                 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
2367                                 // We should have already seen a `ChannelForceClosed` update if we're trying to
2368                                 // provide a preimage at this point.
2369                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
2370                                         debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
2371                                 _ => {
2372                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2373                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2374                                 },
2375                         }
2376                 } else if self.latest_update_id + 1 != updates.update_id {
2377                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2378                 }
2379                 let mut ret = Ok(());
2380                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2381                 for update in updates.updates.iter() {
2382                         match update {
2383                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs, nondust_htlc_sources } => {
2384                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2385                                         if self.lockdown_from_offchain { panic!(); }
2386                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs, nondust_htlc_sources.clone()) {
2387                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2388                                                 log_error!(logger, "    {}", e);
2389                                                 ret = Err(());
2390                                         }
2391                                 }
2392                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
2393                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2394                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2395                                 },
2396                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2397                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2398                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2399                                 },
2400                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2401                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2402                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2403                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2404                                                 log_error!(logger, "    {}", e);
2405                                                 ret = Err(());
2406                                         }
2407                                 },
2408                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2409                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2410                                         self.lockdown_from_offchain = true;
2411                                         if *should_broadcast {
2412                                                 // There's no need to broadcast our commitment transaction if we've seen one
2413                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2414                                                 // duplicate/conflicting.
2415                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2416                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2417                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2418                                                                 _ => false,
2419                                                         }).is_some();
2420                                                 if detected_funding_spend {
2421                                                         log_trace!(logger, "Avoiding commitment broadcast, already detected confirmed spend onchain");
2422                                                         continue;
2423                                                 }
2424                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2425                                                 // If the channel supports anchor outputs, we'll need to emit an external
2426                                                 // event to be consumed such that a child transaction is broadcast with a
2427                                                 // high enough feerate for the parent commitment transaction to confirm.
2428                                                 if self.onchain_tx_handler.opt_anchors() {
2429                                                         let funding_output = HolderFundingOutput::build(
2430                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2431                                                                 self.onchain_tx_handler.opt_anchors(),
2432                                                         );
2433                                                         let best_block_height = self.best_block.height();
2434                                                         let commitment_package = PackageTemplate::build_package(
2435                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2436                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2437                                                                 best_block_height, best_block_height
2438                                                         );
2439                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2440                                                                 vec![commitment_package], best_block_height, best_block_height,
2441                                                                 broadcaster, &bounded_fee_estimator, logger,
2442                                                         );
2443                                                 }
2444                                         } else if !self.holder_tx_signed {
2445                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2446                                                 log_error!(logger, "    in channel monitor for channel {}!", log_bytes!(self.funding_info.0.to_channel_id()));
2447                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2448                                         } else {
2449                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2450                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2451                                                 // shouldn't print the scary warning above.
2452                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2453                                         }
2454                                 },
2455                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2456                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2457                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2458                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2459                                         }
2460                                 },
2461                         }
2462                 }
2463
2464                 // If the updates succeeded and we were in an already closed channel state, then there's no
2465                 // need to refuse any updates we expect to receive afer seeing a confirmed commitment.
2466                 if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id {
2467                         return Ok(());
2468                 }
2469
2470                 self.latest_update_id = updates.update_id;
2471
2472                 // Refuse updates after we've detected a spend onchain, but only if we haven't processed a
2473                 // force closed monitor update yet.
2474                 if ret.is_ok() && self.funding_spend_seen && self.latest_update_id != CLOSED_CHANNEL_UPDATE_ID {
2475                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2476                         Err(())
2477                 } else { ret }
2478         }
2479
2480         pub fn get_latest_update_id(&self) -> u64 {
2481                 self.latest_update_id
2482         }
2483
2484         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2485                 &self.funding_info
2486         }
2487
2488         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2489                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2490                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2491                 // its trivial to do, double-check that here.
2492                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2493                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2494                 }
2495                 &self.outputs_to_watch
2496         }
2497
2498         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2499                 let mut ret = Vec::new();
2500                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2501                 ret
2502         }
2503
2504         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2505                 let mut ret = Vec::new();
2506                 mem::swap(&mut ret, &mut self.pending_events);
2507                 #[cfg(anchors)]
2508                 for claim_event in self.onchain_tx_handler.get_and_clear_pending_claim_events().drain(..) {
2509                         match claim_event {
2510                                 ClaimEvent::BumpCommitment {
2511                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2512                                 } => {
2513                                         let commitment_txid = commitment_tx.txid();
2514                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2515                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2516                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2517                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2518                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2519                                                 package_target_feerate_sat_per_1000_weight,
2520                                                 commitment_tx,
2521                                                 commitment_tx_fee_satoshis,
2522                                                 anchor_descriptor: AnchorDescriptor {
2523                                                         channel_keys_id: self.channel_keys_id,
2524                                                         channel_value_satoshis: self.channel_value_satoshis,
2525                                                         outpoint: BitcoinOutPoint {
2526                                                                 txid: commitment_txid,
2527                                                                 vout: anchor_output_idx,
2528                                                         },
2529                                                 },
2530                                                 pending_htlcs,
2531                                         }));
2532                                 },
2533                                 ClaimEvent::BumpHTLC {
2534                                         target_feerate_sat_per_1000_weight, htlcs, tx_lock_time,
2535                                 } => {
2536                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2537                                         for htlc in htlcs {
2538                                                 htlc_descriptors.push(HTLCDescriptor {
2539                                                         channel_keys_id: self.channel_keys_id,
2540                                                         channel_value_satoshis: self.channel_value_satoshis,
2541                                                         channel_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2542                                                         commitment_txid: htlc.commitment_txid,
2543                                                         per_commitment_number: htlc.per_commitment_number,
2544                                                         htlc: htlc.htlc,
2545                                                         preimage: htlc.preimage,
2546                                                         counterparty_sig: htlc.counterparty_sig,
2547                                                 });
2548                                         }
2549                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2550                                                 target_feerate_sat_per_1000_weight,
2551                                                 htlc_descriptors,
2552                                                 tx_lock_time,
2553                                         }));
2554                                 }
2555                         }
2556                 }
2557                 ret
2558         }
2559
2560         /// Can only fail if idx is < get_min_seen_secret
2561         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2562                 self.commitment_secrets.get_secret(idx)
2563         }
2564
2565         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2566                 self.commitment_secrets.get_min_seen_secret()
2567         }
2568
2569         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2570                 self.current_counterparty_commitment_number
2571         }
2572
2573         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2574                 self.current_holder_commitment_number
2575         }
2576
2577         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2578         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2579         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2580         /// HTLC-Success/HTLC-Timeout transactions.
2581         ///
2582         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2583         /// general information about the output that is to the counterparty in the commitment
2584         /// transaction.
2585         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2586                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2587         where L::Target: Logger {
2588                 // Most secp and related errors trying to create keys means we have no hope of constructing
2589                 // a spend transaction...so we return no transactions to broadcast
2590                 let mut claimable_outpoints = Vec::new();
2591                 let mut watch_outputs = Vec::new();
2592                 let mut to_counterparty_output_info = None;
2593
2594                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2595                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2596
2597                 macro_rules! ignore_error {
2598                         ( $thing : expr ) => {
2599                                 match $thing {
2600                                         Ok(a) => a,
2601                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2602                                 }
2603                         };
2604                 }
2605
2606                 let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence.0 as u64 & 0xffffff) << 3*8) | (tx.lock_time.0 as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
2607                 if commitment_number >= self.get_min_seen_secret() {
2608                         let secret = self.get_secret(commitment_number).unwrap();
2609                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2610                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2611                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2612                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx, &PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2613
2614                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2615                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2616
2617                         // First, process non-htlc outputs (to_holder & to_counterparty)
2618                         for (idx, outp) in tx.output.iter().enumerate() {
2619                                 if outp.script_pubkey == revokeable_p2wsh {
2620                                         let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_commitment_params.on_counterparty_tx_csv, self.onchain_tx_handler.opt_anchors());
2621                                         let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height);
2622                                         claimable_outpoints.push(justice_package);
2623                                         to_counterparty_output_info =
2624                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2625                                 }
2626                         }
2627
2628                         // Then, try to find revoked htlc outputs
2629                         if let Some(ref per_commitment_data) = per_commitment_option {
2630                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2631                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2632                                                 if transaction_output_index as usize >= tx.output.len() ||
2633                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2634                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2635                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2636                                                                 to_counterparty_output_info);
2637                                                 }
2638                                                 let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_some());
2639                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, height);
2640                                                 claimable_outpoints.push(justice_package);
2641                                         }
2642                                 }
2643                         }
2644
2645                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2646                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2647                                 // We're definitely a counterparty commitment transaction!
2648                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2649                                 for (idx, outp) in tx.output.iter().enumerate() {
2650                                         watch_outputs.push((idx as u32, outp.clone()));
2651                                 }
2652                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2653
2654                                 if let Some(per_commitment_data) = per_commitment_option {
2655                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2656                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2657                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2658                                                 ), logger);
2659                                 } else {
2660                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2661                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2662                                                 block_hash, [].iter().map(|reference| *reference), logger);
2663                                 }
2664                         }
2665                 } else if let Some(per_commitment_data) = per_commitment_option {
2666                         // While this isn't useful yet, there is a potential race where if a counterparty
2667                         // revokes a state at the same time as the commitment transaction for that state is
2668                         // confirmed, and the watchtower receives the block before the user, the user could
2669                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2670                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2671                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2672                         // insert it here.
2673                         for (idx, outp) in tx.output.iter().enumerate() {
2674                                 watch_outputs.push((idx as u32, outp.clone()));
2675                         }
2676                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2677
2678                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2679                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
2680                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2681                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2682                                 ), logger);
2683
2684                         let (htlc_claim_reqs, counterparty_output_info) =
2685                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
2686                         to_counterparty_output_info = counterparty_output_info;
2687                         for req in htlc_claim_reqs {
2688                                 claimable_outpoints.push(req);
2689                         }
2690
2691                 }
2692                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2693         }
2694
2695         /// Returns the HTLC claim package templates and the counterparty output info
2696         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
2697         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
2698                 let mut claimable_outpoints = Vec::new();
2699                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
2700
2701                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
2702                         Some(outputs) => outputs,
2703                         None => return (claimable_outpoints, to_counterparty_output_info),
2704                 };
2705                 let per_commitment_points = match self.their_cur_per_commitment_points {
2706                         Some(points) => points,
2707                         None => return (claimable_outpoints, to_counterparty_output_info),
2708                 };
2709
2710                 let per_commitment_point =
2711                         // If the counterparty commitment tx is the latest valid state, use their latest
2712                         // per-commitment point
2713                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
2714                         else if let Some(point) = per_commitment_points.2.as_ref() {
2715                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2716                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2717                                 // them to temporarily have two valid commitment txns from our viewpoint)
2718                                 if per_commitment_points.0 == commitment_number + 1 {
2719                                         point
2720                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
2721                         } else { return (claimable_outpoints, to_counterparty_output_info); };
2722
2723                 if let Some(transaction) = tx {
2724                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
2725                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2726                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2727                                 &per_commitment_point,
2728                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2729                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2730                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
2731                                 &delayed_key).to_v0_p2wsh();
2732                         for (idx, outp) in transaction.output.iter().enumerate() {
2733                                 if outp.script_pubkey == revokeable_p2wsh {
2734                                         to_counterparty_output_info =
2735                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
2736                                 }
2737                         }
2738                 }
2739
2740                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2741                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2742                                 if let Some(transaction) = tx {
2743                                         if transaction_output_index as usize >= transaction.output.len() ||
2744                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2745                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2746                                                         return (claimable_outpoints, to_counterparty_output_info);
2747                                                 }
2748                                 }
2749                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2750                                 if preimage.is_some() || !htlc.offered {
2751                                         let counterparty_htlc_outp = if htlc.offered {
2752                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
2753                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2754                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2755                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2756                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2757                                         } else {
2758                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
2759                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2760                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2761                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
2762                                                                 htlc.clone(), self.onchain_tx_handler.opt_anchors()))
2763                                         };
2764                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry, 0);
2765                                         claimable_outpoints.push(counterparty_package);
2766                                 }
2767                         }
2768                 }
2769
2770                 (claimable_outpoints, to_counterparty_output_info)
2771         }
2772
2773         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2774         fn check_spend_counterparty_htlc<L: Deref>(
2775                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
2776         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2777                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2778                 let per_commitment_key = match SecretKey::from_slice(&secret) {
2779                         Ok(key) => key,
2780                         Err(_) => return (Vec::new(), None)
2781                 };
2782                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2783
2784                 let htlc_txid = tx.txid();
2785                 let mut claimable_outpoints = vec![];
2786                 let mut outputs_to_watch = None;
2787                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
2788                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
2789                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
2790                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
2791                 // confirmed revoked HTLC transaction (for more details, see
2792                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
2793                 //
2794                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
2795                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
2796                 // have a corresponding output at the same index within the transaction.
2797                 for (idx, input) in tx.input.iter().enumerate() {
2798                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
2799                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
2800                                 let revk_outp = RevokedOutput::build(
2801                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2802                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
2803                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv,
2804                                         false
2805                                 );
2806                                 let justice_package = PackageTemplate::build_package(
2807                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
2808                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height
2809                                 );
2810                                 claimable_outpoints.push(justice_package);
2811                                 if outputs_to_watch.is_none() {
2812                                         outputs_to_watch = Some((htlc_txid, vec![]));
2813                                 }
2814                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
2815                         }
2816                 }
2817                 (claimable_outpoints, outputs_to_watch)
2818         }
2819
2820         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
2821         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2822         // script so we can detect whether a holder transaction has been seen on-chain.
2823         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2824                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2825
2826                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2827                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2828
2829                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2830                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2831                                 let htlc_output = if htlc.offered {
2832                                         let htlc_output = HolderHTLCOutput::build_offered(
2833                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.opt_anchors()
2834                                         );
2835                                         htlc_output
2836                                 } else {
2837                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2838                                                 preimage.clone()
2839                                         } else {
2840                                                 // We can't build an HTLC-Success transaction without the preimage
2841                                                 continue;
2842                                         };
2843                                         let htlc_output = HolderHTLCOutput::build_accepted(
2844                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.opt_anchors()
2845                                         );
2846                                         htlc_output
2847                                 };
2848                                 let htlc_package = PackageTemplate::build_package(
2849                                         holder_tx.txid, transaction_output_index,
2850                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
2851                                         htlc.cltv_expiry, conf_height
2852                                 );
2853                                 claim_requests.push(htlc_package);
2854                         }
2855                 }
2856
2857                 (claim_requests, broadcasted_holder_revokable_script)
2858         }
2859
2860         // Returns holder HTLC outputs to watch and react to in case of spending.
2861         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2862                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2863                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2864                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2865                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2866                         }
2867                 }
2868                 watch_outputs
2869         }
2870
2871         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2872         /// revoked using data in holder_claimable_outpoints.
2873         /// Should not be used if check_spend_revoked_transaction succeeds.
2874         /// Returns None unless the transaction is definitely one of our commitment transactions.
2875         fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) -> Option<(Vec<PackageTemplate>, TransactionOutputs)> where L::Target: Logger {
2876                 let commitment_txid = tx.txid();
2877                 let mut claim_requests = Vec::new();
2878                 let mut watch_outputs = Vec::new();
2879
2880                 macro_rules! append_onchain_update {
2881                         ($updates: expr, $to_watch: expr) => {
2882                                 claim_requests = $updates.0;
2883                                 self.broadcasted_holder_revokable_script = $updates.1;
2884                                 watch_outputs.append(&mut $to_watch);
2885                         }
2886                 }
2887
2888                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2889                 let mut is_holder_tx = false;
2890
2891                 if self.current_holder_commitment_tx.txid == commitment_txid {
2892                         is_holder_tx = true;
2893                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2894                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2895                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2896                         append_onchain_update!(res, to_watch);
2897                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
2898                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
2899                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2900                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2901                         if holder_tx.txid == commitment_txid {
2902                                 is_holder_tx = true;
2903                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2904                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2905                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2906                                 append_onchain_update!(res, to_watch);
2907                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
2908                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2909                                         logger);
2910                         }
2911                 }
2912
2913                 if is_holder_tx {
2914                         Some((claim_requests, (commitment_txid, watch_outputs)))
2915                 } else {
2916                         None
2917                 }
2918         }
2919
2920         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2921                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2922                 self.holder_tx_signed = true;
2923                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2924                 let txid = commitment_tx.txid();
2925                 let mut holder_transactions = vec![commitment_tx];
2926                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
2927                 // transaction confirms.
2928                 if self.onchain_tx_handler.opt_anchors() {
2929                         return holder_transactions;
2930                 }
2931                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2932                         if let Some(vout) = htlc.0.transaction_output_index {
2933                                 let preimage = if !htlc.0.offered {
2934                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2935                                                 // We can't build an HTLC-Success transaction without the preimage
2936                                                 continue;
2937                                         }
2938                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2939                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2940                                         // current locktime requirements on-chain. We will broadcast them in
2941                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2942                                         // Note that we add + 1 as transactions are broadcastable when they can be
2943                                         // confirmed in the next block.
2944                                         continue;
2945                                 } else { None };
2946                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2947                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2948                                         holder_transactions.push(htlc_tx);
2949                                 }
2950                         }
2951                 }
2952                 // 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.
2953                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2954                 holder_transactions
2955         }
2956
2957         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2958         /// Note that this includes possibly-locktimed-in-the-future transactions!
2959         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2960                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2961                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2962                 let txid = commitment_tx.txid();
2963                 let mut holder_transactions = vec![commitment_tx];
2964                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
2965                 // transaction confirms due to the CSV 1 encumberance.
2966                 if self.onchain_tx_handler.opt_anchors() {
2967                         return holder_transactions;
2968                 }
2969                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2970                         if let Some(vout) = htlc.0.transaction_output_index {
2971                                 let preimage = if !htlc.0.offered {
2972                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2973                                                 // We can't build an HTLC-Success transaction without the preimage
2974                                                 continue;
2975                                         }
2976                                 } else { None };
2977                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2978                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2979                                         holder_transactions.push(htlc_tx);
2980                                 }
2981                         }
2982                 }
2983                 holder_transactions
2984         }
2985
2986         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<TransactionOutputs>
2987                 where B::Target: BroadcasterInterface,
2988                       F::Target: FeeEstimator,
2989                                         L::Target: Logger,
2990         {
2991                 let block_hash = header.block_hash();
2992                 self.best_block = BestBlock::new(block_hash, height);
2993
2994                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2995                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2996         }
2997
2998         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2999                 &mut self,
3000                 header: &BlockHeader,
3001                 height: u32,
3002                 broadcaster: B,
3003                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3004                 logger: L,
3005         ) -> Vec<TransactionOutputs>
3006         where
3007                 B::Target: BroadcasterInterface,
3008                 F::Target: FeeEstimator,
3009                 L::Target: Logger,
3010         {
3011                 let block_hash = header.block_hash();
3012
3013                 if height > self.best_block.height() {
3014                         self.best_block = BestBlock::new(block_hash, height);
3015                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
3016                 } else if block_hash != self.best_block.block_hash() {
3017                         self.best_block = BestBlock::new(block_hash, height);
3018                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
3019                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
3020                         Vec::new()
3021                 } else { Vec::new() }
3022         }
3023
3024         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
3025                 &mut self,
3026                 header: &BlockHeader,
3027                 txdata: &TransactionData,
3028                 height: u32,
3029                 broadcaster: B,
3030                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3031                 logger: L,
3032         ) -> Vec<TransactionOutputs>
3033         where
3034                 B::Target: BroadcasterInterface,
3035                 F::Target: FeeEstimator,
3036                 L::Target: Logger,
3037         {
3038                 let txn_matched = self.filter_block(txdata);
3039                 for tx in &txn_matched {
3040                         let mut output_val = 0;
3041                         for out in tx.output.iter() {
3042                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
3043                                 output_val += out.value;
3044                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
3045                         }
3046                 }
3047
3048                 let block_hash = header.block_hash();
3049
3050                 let mut watch_outputs = Vec::new();
3051                 let mut claimable_outpoints = Vec::new();
3052                 'tx_iter: for tx in &txn_matched {
3053                         let txid = tx.txid();
3054                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
3055                         if Some(txid) == self.funding_spend_confirmed {
3056                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
3057                                 continue 'tx_iter;
3058                         }
3059                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
3060                                 if ev.txid == txid {
3061                                         if let Some(conf_hash) = ev.block_hash {
3062                                                 assert_eq!(header.block_hash(), conf_hash,
3063                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
3064                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
3065                                         }
3066                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
3067                                         continue 'tx_iter;
3068                                 }
3069                         }
3070                         for htlc in self.htlcs_resolved_on_chain.iter() {
3071                                 if Some(txid) == htlc.resolving_txid {
3072                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
3073                                         continue 'tx_iter;
3074                                 }
3075                         }
3076                         for spendable_txid in self.spendable_txids_confirmed.iter() {
3077                                 if txid == *spendable_txid {
3078                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
3079                                         continue 'tx_iter;
3080                                 }
3081                         }
3082
3083                         if tx.input.len() == 1 {
3084                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
3085                                 // commitment transactions and HTLC transactions will all only ever have one input
3086                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
3087                                 // way to filter out any potential non-matching txn for lazy filters.
3088                                 let prevout = &tx.input[0].previous_output;
3089                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
3090                                         let mut balance_spendable_csv = None;
3091                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
3092                                                 log_bytes!(self.funding_info.0.to_channel_id()), txid);
3093                                         self.funding_spend_seen = true;
3094                                         let mut commitment_tx_to_counterparty_output = None;
3095                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
3096                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
3097                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
3098                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
3099                                                 if !new_outputs.1.is_empty() {
3100                                                         watch_outputs.push(new_outputs);
3101                                                 }
3102                                                 claimable_outpoints.append(&mut new_outpoints);
3103                                                 if new_outpoints.is_empty() {
3104                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
3105                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
3106                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
3107                                                                 if !new_outputs.1.is_empty() {
3108                                                                         watch_outputs.push(new_outputs);
3109                                                                 }
3110                                                                 claimable_outpoints.append(&mut new_outpoints);
3111                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
3112                                                         }
3113                                                 }
3114                                         }
3115                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3116                                                 txid,
3117                                                 transaction: Some((*tx).clone()),
3118                                                 height,
3119                                                 block_hash: Some(block_hash),
3120                                                 event: OnchainEvent::FundingSpendConfirmation {
3121                                                         on_local_output_csv: balance_spendable_csv,
3122                                                         commitment_tx_to_counterparty_output,
3123                                                 },
3124                                         });
3125                                 }
3126                         }
3127                         if tx.input.len() >= 1 {
3128                                 // While all commitment transactions have one input, HTLC transactions may have more
3129                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
3130                                 // other ways which can have more than one output.
3131                                 for tx_input in &tx.input {
3132                                         let commitment_txid = tx_input.previous_output.txid;
3133                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
3134                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
3135                                                         &tx, commitment_number, &commitment_txid, height, &logger
3136                                                 );
3137                                                 claimable_outpoints.append(&mut new_outpoints);
3138                                                 if let Some(new_outputs) = new_outputs_option {
3139                                                         watch_outputs.push(new_outputs);
3140                                                 }
3141                                                 // Since there may be multiple HTLCs for this channel (all spending the
3142                                                 // same commitment tx) being claimed by the counterparty within the same
3143                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
3144                                                 // ones relevant to this channel, we can safely break from our loop.
3145                                                 break;
3146                                         }
3147                                 }
3148                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3149
3150                                 self.is_paying_spendable_output(&tx, height, &block_hash, &logger);
3151                         }
3152                 }
3153
3154                 if height > self.best_block.height() {
3155                         self.best_block = BestBlock::new(block_hash, height);
3156                 }
3157
3158                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3159         }
3160
3161         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3162         /// `self.best_block` before calling if a new best blockchain tip is available. More
3163         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3164         /// complexity especially in
3165         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3166         ///
3167         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3168         /// confirmed at, even if it is not the current best height.
3169         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3170                 &mut self,
3171                 conf_height: u32,
3172                 conf_hash: BlockHash,
3173                 txn_matched: Vec<&Transaction>,
3174                 mut watch_outputs: Vec<TransactionOutputs>,
3175                 mut claimable_outpoints: Vec<PackageTemplate>,
3176                 broadcaster: &B,
3177                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3178                 logger: &L,
3179         ) -> Vec<TransactionOutputs>
3180         where
3181                 B::Target: BroadcasterInterface,
3182                 F::Target: FeeEstimator,
3183                 L::Target: Logger,
3184         {
3185                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3186                 debug_assert!(self.best_block.height() >= conf_height);
3187
3188                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3189                 if should_broadcast {
3190                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.opt_anchors());
3191                         let commitment_package = PackageTemplate::build_package(self.funding_info.0.txid.clone(), self.funding_info.0.index as u32, PackageSolvingData::HolderFundingOutput(funding_outp), self.best_block.height(), self.best_block.height());
3192                         claimable_outpoints.push(commitment_package);
3193                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
3194                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3195                         self.holder_tx_signed = true;
3196                         // We can't broadcast our HTLC transactions while the commitment transaction is
3197                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3198                         // `transactions_confirmed`.
3199                         if !self.onchain_tx_handler.opt_anchors() {
3200                                 // Because we're broadcasting a commitment transaction, we should construct the package
3201                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3202                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3203                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3204                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
3205                                 if !new_outputs.is_empty() {
3206                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3207                                 }
3208                                 claimable_outpoints.append(&mut new_outpoints);
3209                         }
3210                 }
3211
3212                 // Find which on-chain events have reached their confirmation threshold.
3213                 let onchain_events_awaiting_threshold_conf =
3214                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3215                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3216                 for entry in onchain_events_awaiting_threshold_conf {
3217                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3218                                 onchain_events_reaching_threshold_conf.push(entry);
3219                         } else {
3220                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3221                         }
3222                 }
3223
3224                 // Used to check for duplicate HTLC resolutions.
3225                 #[cfg(debug_assertions)]
3226                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3227                         .iter()
3228                         .filter_map(|entry| match &entry.event {
3229                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3230                                 _ => None,
3231                         })
3232                         .collect();
3233                 #[cfg(debug_assertions)]
3234                 let mut matured_htlcs = Vec::new();
3235
3236                 // Produce actionable events from on-chain events having reached their threshold.
3237                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3238                         match entry.event {
3239                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3240                                         // Check for duplicate HTLC resolutions.
3241                                         #[cfg(debug_assertions)]
3242                                         {
3243                                                 debug_assert!(
3244                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3245                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3246                                                          call either transaction_unconfirmed for the conflicting transaction \
3247                                                          or block_disconnected for a block containing it.");
3248                                                 debug_assert!(
3249                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3250                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3251                                                          call either transaction_unconfirmed for the conflicting transaction \
3252                                                          or block_disconnected for a block containing it.");
3253                                                 matured_htlcs.push(source.clone());
3254                                         }
3255
3256                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3257                                                 log_bytes!(payment_hash.0), entry.txid);
3258                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3259                                                 payment_hash,
3260                                                 payment_preimage: None,
3261                                                 source: source.clone(),
3262                                                 htlc_value_satoshis,
3263                                         }));
3264                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3265                                                 commitment_tx_output_idx,
3266                                                 resolving_txid: Some(entry.txid),
3267                                                 resolving_tx: entry.transaction,
3268                                                 payment_preimage: None,
3269                                         });
3270                                 },
3271                                 OnchainEvent::MaturingOutput { descriptor } => {
3272                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3273                                         self.pending_events.push(Event::SpendableOutputs {
3274                                                 outputs: vec![descriptor]
3275                                         });
3276                                         self.spendable_txids_confirmed.push(entry.txid);
3277                                 },
3278                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3279                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3280                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3281                                                 resolving_txid: Some(entry.txid),
3282                                                 resolving_tx: entry.transaction,
3283                                                 payment_preimage: preimage,
3284                                         });
3285                                 },
3286                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3287                                         self.funding_spend_confirmed = Some(entry.txid);
3288                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3289                                 },
3290                         }
3291                 }
3292
3293                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3294                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3295
3296                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3297                 // updating the latter in the process.
3298                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3299                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3300                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3301                 });
3302                 #[cfg(test)]
3303                 {
3304                         // If we see a transaction for which we registered outputs previously,
3305                         // make sure the registered scriptpubkey at the expected index match
3306                         // the actual transaction output one. We failed this case before #653.
3307                         for tx in &txn_matched {
3308                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3309                                         for idx_and_script in outputs.iter() {
3310                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3311                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3312                                         }
3313                                 }
3314                         }
3315                 }
3316                 watch_outputs
3317         }
3318
3319         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3320                 where B::Target: BroadcasterInterface,
3321                       F::Target: FeeEstimator,
3322                       L::Target: Logger,
3323         {
3324                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3325
3326                 //We may discard:
3327                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3328                 //- maturing spendable output has transaction paying us has been disconnected
3329                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3330
3331                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3332                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3333
3334                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3335         }
3336
3337         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3338                 &mut self,
3339                 txid: &Txid,
3340                 broadcaster: B,
3341                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3342                 logger: L,
3343         ) where
3344                 B::Target: BroadcasterInterface,
3345                 F::Target: FeeEstimator,
3346                 L::Target: Logger,
3347         {
3348                 let mut removed_height = None;
3349                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3350                         if entry.txid == *txid {
3351                                 removed_height = Some(entry.height);
3352                                 break;
3353                         }
3354                 }
3355
3356                 if let Some(removed_height) = removed_height {
3357                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3358                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3359                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3360                                 false
3361                         } else { true });
3362                 }
3363
3364                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3365
3366                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3367         }
3368
3369         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3370         /// transactions thereof.
3371         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3372                 let mut matched_txn = HashSet::new();
3373                 txdata.iter().filter(|&&(_, tx)| {
3374                         let mut matches = self.spends_watched_output(tx);
3375                         for input in tx.input.iter() {
3376                                 if matches { break; }
3377                                 if matched_txn.contains(&input.previous_output.txid) {
3378                                         matches = true;
3379                                 }
3380                         }
3381                         if matches {
3382                                 matched_txn.insert(tx.txid());
3383                         }
3384                         matches
3385                 }).map(|(_, tx)| *tx).collect()
3386         }
3387
3388         /// Checks if a given transaction spends any watched outputs.
3389         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3390                 for input in tx.input.iter() {
3391                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3392                                 for (idx, _script_pubkey) in outputs.iter() {
3393                                         if *idx == input.previous_output.vout {
3394                                                 #[cfg(test)]
3395                                                 {
3396                                                         // If the expected script is a known type, check that the witness
3397                                                         // appears to be spending the correct type (ie that the match would
3398                                                         // actually succeed in BIP 158/159-style filters).
3399                                                         if _script_pubkey.is_v0_p2wsh() {
3400                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3401                                                                         // In at least one test we use a deliberately bogus witness
3402                                                                         // script which hit an old panic. Thus, we check for that here
3403                                                                         // and avoid the assert if its the expected bogus script.
3404                                                                         return true;
3405                                                                 }
3406
3407                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3408                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3409                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3410                                                         } else { panic!(); }
3411                                                 }
3412                                                 return true;
3413                                         }
3414                                 }
3415                         }
3416                 }
3417
3418                 false
3419         }
3420
3421         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3422                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3423                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3424                 if self.funding_spend_confirmed.is_some() ||
3425                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3426                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3427                                 _ => false,
3428                         }).is_some()
3429                 {
3430                         return false;
3431                 }
3432                 // We need to consider all HTLCs which are:
3433                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3434                 //    transactions and we'd end up in a race, or
3435                 //  * are in our latest holder commitment transaction, as this is the thing we will
3436                 //    broadcast if we go on-chain.
3437                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3438                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3439                 // to the source, and if we don't fail the channel we will have to ensure that the next
3440                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3441                 // easier to just fail the channel as this case should be rare enough anyway.
3442                 let height = self.best_block.height();
3443                 macro_rules! scan_commitment {
3444                         ($htlcs: expr, $holder_tx: expr) => {
3445                                 for ref htlc in $htlcs {
3446                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3447                                         // chain with enough room to claim the HTLC without our counterparty being able to
3448                                         // time out the HTLC first.
3449                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3450                                         // concern is being able to claim the corresponding inbound HTLC (on another
3451                                         // channel) before it expires. In fact, we don't even really care if our
3452                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3453                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3454                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3455                                         // we give ourselves a few blocks of headroom after expiration before going
3456                                         // on-chain for an expired HTLC.
3457                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3458                                         // from us until we've reached the point where we go on-chain with the
3459                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3460                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3461                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3462                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3463                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3464                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3465                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3466                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3467                                         //  The final, above, condition is checked for statically in channelmanager
3468                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3469                                         let htlc_outbound = $holder_tx == htlc.offered;
3470                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3471                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3472                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3473                                                 return true;
3474                                         }
3475                                 }
3476                         }
3477                 }
3478
3479                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3480
3481                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3482                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3483                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3484                         }
3485                 }
3486                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3487                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3488                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3489                         }
3490                 }
3491
3492                 false
3493         }
3494
3495         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3496         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3497         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3498                 'outer_loop: for input in &tx.input {
3499                         let mut payment_data = None;
3500                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3501                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3502                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3503                         #[cfg(not(fuzzing))]
3504                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3505                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3506                         #[cfg(not(fuzzing))]
3507                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3508
3509                         let mut payment_preimage = PaymentPreimage([0; 32]);
3510                         if offered_preimage_claim || accepted_preimage_claim {
3511                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3512                         }
3513
3514                         macro_rules! log_claim {
3515                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3516                                         let outbound_htlc = $holder_tx == $htlc.offered;
3517                                         // HTLCs must either be claimed by a matching script type or through the
3518                                         // revocation path:
3519                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3520                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3521                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3522                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3523                                         // Further, only exactly one of the possible spend paths should have been
3524                                         // matched by any HTLC spend:
3525                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3526                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3527                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3528                                                          revocation_sig_claim as u8, 1);
3529                                         if ($holder_tx && revocation_sig_claim) ||
3530                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3531                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3532                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3533                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3534                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back. We can likely claim the HTLC output with a revocation claim" });
3535                                         } else {
3536                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3537                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3538                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
3539                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3540                                         }
3541                                 }
3542                         }
3543
3544                         macro_rules! check_htlc_valid_counterparty {
3545                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3546                                         if let Some(txid) = $counterparty_txid {
3547                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3548                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3549                                                                 if let &Some(ref source) = pending_source {
3550                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3551                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3552                                                                         break;
3553                                                                 }
3554                                                         }
3555                                                 }
3556                                         }
3557                                 }
3558                         }
3559
3560                         macro_rules! scan_commitment {
3561                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3562                                         for (ref htlc_output, source_option) in $htlcs {
3563                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3564                                                         if let Some(ref source) = source_option {
3565                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3566                                                                 // We have a resolution of an HTLC either from one of our latest
3567                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3568                                                                 // transaction. This implies we either learned a preimage, the HTLC
3569                                                                 // has timed out, or we screwed up. In any case, we should now
3570                                                                 // resolve the source HTLC with the original sender.
3571                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3572                                                         } else if !$holder_tx {
3573                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3574                                                                 if payment_data.is_none() {
3575                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3576                                                                 }
3577                                                         }
3578                                                         if payment_data.is_none() {
3579                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3580                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3581                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3582                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3583                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3584                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3585                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3586                                                                                         Some(payment_preimage) } else { None },
3587                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3588                                                                                 // the CSV delay before dropping the HTLC from claimable
3589                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3590                                                                                 // accepted_preimage_claim).
3591                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3592                                                                                         Some(self.on_holder_tx_csv) } else { None },
3593                                                                         },
3594                                                                 });
3595                                                                 continue 'outer_loop;
3596                                                         }
3597                                                 }
3598                                         }
3599                                 }
3600                         }
3601
3602                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3603                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3604                                         "our latest holder commitment tx", true);
3605                         }
3606                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3607                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3608                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3609                                                 "our previous holder commitment tx", true);
3610                                 }
3611                         }
3612                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3613                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3614                                         "counterparty commitment tx", false);
3615                         }
3616
3617                         // Check that scan_commitment, above, decided there is some source worth relaying an
3618                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3619                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3620                                 if accepted_preimage_claim {
3621                                         if !self.pending_monitor_events.iter().any(
3622                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3623                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3624                                                         txid: tx.txid(),
3625                                                         height,
3626                                                         block_hash: Some(*block_hash),
3627                                                         transaction: Some(tx.clone()),
3628                                                         event: OnchainEvent::HTLCSpendConfirmation {
3629                                                                 commitment_tx_output_idx: input.previous_output.vout,
3630                                                                 preimage: Some(payment_preimage),
3631                                                                 on_to_local_output_csv: None,
3632                                                         },
3633                                                 });
3634                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3635                                                         source,
3636                                                         payment_preimage: Some(payment_preimage),
3637                                                         payment_hash,
3638                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3639                                                 }));
3640                                         }
3641                                 } else if offered_preimage_claim {
3642                                         if !self.pending_monitor_events.iter().any(
3643                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3644                                                         upd.source == source
3645                                                 } else { false }) {
3646                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3647                                                         txid: tx.txid(),
3648                                                         transaction: Some(tx.clone()),
3649                                                         height,
3650                                                         block_hash: Some(*block_hash),
3651                                                         event: OnchainEvent::HTLCSpendConfirmation {
3652                                                                 commitment_tx_output_idx: input.previous_output.vout,
3653                                                                 preimage: Some(payment_preimage),
3654                                                                 on_to_local_output_csv: None,
3655                                                         },
3656                                                 });
3657                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3658                                                         source,
3659                                                         payment_preimage: Some(payment_preimage),
3660                                                         payment_hash,
3661                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3662                                                 }));
3663                                         }
3664                                 } else {
3665                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3666                                                 if entry.height != height { return true; }
3667                                                 match entry.event {
3668                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3669                                                                 *htlc_source != source
3670                                                         },
3671                                                         _ => true,
3672                                                 }
3673                                         });
3674                                         let entry = OnchainEventEntry {
3675                                                 txid: tx.txid(),
3676                                                 transaction: Some(tx.clone()),
3677                                                 height,
3678                                                 block_hash: Some(*block_hash),
3679                                                 event: OnchainEvent::HTLCUpdate {
3680                                                         source, payment_hash,
3681                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3682                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3683                                                 },
3684                                         };
3685                                         log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
3686                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3687                                 }
3688                         }
3689                 }
3690         }
3691
3692         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3693         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3694                 let mut spendable_output = None;
3695                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3696                         if i > ::core::u16::MAX as usize {
3697                                 // While it is possible that an output exists on chain which is greater than the
3698                                 // 2^16th output in a given transaction, this is only possible if the output is not
3699                                 // in a lightning transaction and was instead placed there by some third party who
3700                                 // wishes to give us money for no reason.
3701                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3702                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3703                                 // scripts are not longer than one byte in length and because they are inherently
3704                                 // non-standard due to their size.
3705                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3706                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3707                                 // nearly a full block with garbage just to hit this case.
3708                                 continue;
3709                         }
3710                         if outp.script_pubkey == self.destination_script {
3711                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3712                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3713                                         output: outp.clone(),
3714                                 });
3715                                 break;
3716                         }
3717                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3718                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3719                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3720                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3721                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3722                                                 to_self_delay: self.on_holder_tx_csv,
3723                                                 output: outp.clone(),
3724                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3725                                                 channel_keys_id: self.channel_keys_id,
3726                                                 channel_value_satoshis: self.channel_value_satoshis,
3727                                         }));
3728                                         break;
3729                                 }
3730                         }
3731                         if self.counterparty_payment_script == outp.script_pubkey {
3732                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3733                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3734                                         output: outp.clone(),
3735                                         channel_keys_id: self.channel_keys_id,
3736                                         channel_value_satoshis: self.channel_value_satoshis,
3737                                 }));
3738                                 break;
3739                         }
3740                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3741                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3742                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3743                                         output: outp.clone(),
3744                                 });
3745                                 break;
3746                         }
3747                 }
3748                 if let Some(spendable_output) = spendable_output {
3749                         let entry = OnchainEventEntry {
3750                                 txid: tx.txid(),
3751                                 transaction: Some(tx.clone()),
3752                                 height,
3753                                 block_hash: Some(*block_hash),
3754                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3755                         };
3756                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3757                         self.onchain_events_awaiting_threshold_conf.push(entry);
3758                 }
3759         }
3760 }
3761
3762 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3763 where
3764         T::Target: BroadcasterInterface,
3765         F::Target: FeeEstimator,
3766         L::Target: Logger,
3767 {
3768         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3769                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3770         }
3771
3772         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3773                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3774         }
3775 }
3776
3777 impl<Signer: WriteableEcdsaChannelSigner, M, T: Deref, F: Deref, L: Deref> chain::Confirm for (M, T, F, L)
3778 where
3779         M: Deref<Target = ChannelMonitor<Signer>>,
3780         T::Target: BroadcasterInterface,
3781         F::Target: FeeEstimator,
3782         L::Target: Logger,
3783 {
3784         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3785                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3786         }
3787
3788         fn transaction_unconfirmed(&self, txid: &Txid) {
3789                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3790         }
3791
3792         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3793                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3794         }
3795
3796         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
3797                 self.0.get_relevant_txids()
3798         }
3799 }
3800
3801 const MAX_ALLOC_SIZE: usize = 64*1024;
3802
3803 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
3804                 for (BlockHash, ChannelMonitor<SP::Signer>) {
3805         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
3806                 macro_rules! unwrap_obj {
3807                         ($key: expr) => {
3808                                 match $key {
3809                                         Ok(res) => res,
3810                                         Err(_) => return Err(DecodeError::InvalidValue),
3811                                 }
3812                         }
3813                 }
3814
3815                 let (entropy_source, signer_provider) = args;
3816
3817                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3818
3819                 let latest_update_id: u64 = Readable::read(reader)?;
3820                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3821
3822                 let destination_script = Readable::read(reader)?;
3823                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3824                         0 => {
3825                                 let revokable_address = Readable::read(reader)?;
3826                                 let per_commitment_point = Readable::read(reader)?;
3827                                 let revokable_script = Readable::read(reader)?;
3828                                 Some((revokable_address, per_commitment_point, revokable_script))
3829                         },
3830                         1 => { None },
3831                         _ => return Err(DecodeError::InvalidValue),
3832                 };
3833                 let counterparty_payment_script = Readable::read(reader)?;
3834                 let shutdown_script = {
3835                         let script = <Script as Readable>::read(reader)?;
3836                         if script.is_empty() { None } else { Some(script) }
3837                 };
3838
3839                 let channel_keys_id = Readable::read(reader)?;
3840                 let holder_revocation_basepoint = Readable::read(reader)?;
3841                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3842                 // barely-init'd ChannelMonitors that we can't do anything with.
3843                 let outpoint = OutPoint {
3844                         txid: Readable::read(reader)?,
3845                         index: Readable::read(reader)?,
3846                 };
3847                 let funding_info = (outpoint, Readable::read(reader)?);
3848                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3849                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3850
3851                 let counterparty_commitment_params = Readable::read(reader)?;
3852                 let funding_redeemscript = Readable::read(reader)?;
3853                 let channel_value_satoshis = Readable::read(reader)?;
3854
3855                 let their_cur_per_commitment_points = {
3856                         let first_idx = <U48 as Readable>::read(reader)?.0;
3857                         if first_idx == 0 {
3858                                 None
3859                         } else {
3860                                 let first_point = Readable::read(reader)?;
3861                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3862                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3863                                         Some((first_idx, first_point, None))
3864                                 } else {
3865                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3866                                 }
3867                         }
3868                 };
3869
3870                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3871
3872                 let commitment_secrets = Readable::read(reader)?;
3873
3874                 macro_rules! read_htlc_in_commitment {
3875                         () => {
3876                                 {
3877                                         let offered: bool = Readable::read(reader)?;
3878                                         let amount_msat: u64 = Readable::read(reader)?;
3879                                         let cltv_expiry: u32 = Readable::read(reader)?;
3880                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3881                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3882
3883                                         HTLCOutputInCommitment {
3884                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3885                                         }
3886                                 }
3887                         }
3888                 }
3889
3890                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3891                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3892                 for _ in 0..counterparty_claimable_outpoints_len {
3893                         let txid: Txid = Readable::read(reader)?;
3894                         let htlcs_count: u64 = Readable::read(reader)?;
3895                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3896                         for _ in 0..htlcs_count {
3897                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3898                         }
3899                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3900                                 return Err(DecodeError::InvalidValue);
3901                         }
3902                 }
3903
3904                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3905                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3906                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3907                         let txid: Txid = Readable::read(reader)?;
3908                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3909                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3910                                 return Err(DecodeError::InvalidValue);
3911                         }
3912                 }
3913
3914                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3915                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3916                 for _ in 0..counterparty_hash_commitment_number_len {
3917                         let payment_hash: PaymentHash = Readable::read(reader)?;
3918                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3919                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3920                                 return Err(DecodeError::InvalidValue);
3921                         }
3922                 }
3923
3924                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3925                         match <u8 as Readable>::read(reader)? {
3926                                 0 => None,
3927                                 1 => {
3928                                         Some(Readable::read(reader)?)
3929                                 },
3930                                 _ => return Err(DecodeError::InvalidValue),
3931                         };
3932                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3933
3934                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3935                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3936
3937                 let payment_preimages_len: u64 = Readable::read(reader)?;
3938                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3939                 for _ in 0..payment_preimages_len {
3940                         let preimage: PaymentPreimage = Readable::read(reader)?;
3941                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3942                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3943                                 return Err(DecodeError::InvalidValue);
3944                         }
3945                 }
3946
3947                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3948                 let mut pending_monitor_events = Some(
3949                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3950                 for _ in 0..pending_monitor_events_len {
3951                         let ev = match <u8 as Readable>::read(reader)? {
3952                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3953                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3954                                 _ => return Err(DecodeError::InvalidValue)
3955                         };
3956                         pending_monitor_events.as_mut().unwrap().push(ev);
3957                 }
3958
3959                 let pending_events_len: u64 = Readable::read(reader)?;
3960                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3961                 for _ in 0..pending_events_len {
3962                         if let Some(event) = MaybeReadable::read(reader)? {
3963                                 pending_events.push(event);
3964                         }
3965                 }
3966
3967                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3968
3969                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3970                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3971                 for _ in 0..waiting_threshold_conf_len {
3972                         if let Some(val) = MaybeReadable::read(reader)? {
3973                                 onchain_events_awaiting_threshold_conf.push(val);
3974                         }
3975                 }
3976
3977                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3978                 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>>())));
3979                 for _ in 0..outputs_to_watch_len {
3980                         let txid = Readable::read(reader)?;
3981                         let outputs_len: u64 = Readable::read(reader)?;
3982                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3983                         for _ in 0..outputs_len {
3984                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3985                         }
3986                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3987                                 return Err(DecodeError::InvalidValue);
3988                         }
3989                 }
3990                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
3991                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
3992                 )?;
3993
3994                 let lockdown_from_offchain = Readable::read(reader)?;
3995                 let holder_tx_signed = Readable::read(reader)?;
3996
3997                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3998                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3999                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
4000                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
4001                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
4002                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
4003                                 return Err(DecodeError::InvalidValue);
4004                         }
4005                 }
4006
4007                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
4008                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
4009                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
4010                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
4011                         return Err(DecodeError::InvalidValue);
4012                 }
4013
4014                 let mut funding_spend_confirmed = None;
4015                 let mut htlcs_resolved_on_chain = Some(Vec::new());
4016                 let mut funding_spend_seen = Some(false);
4017                 let mut counterparty_node_id = None;
4018                 let mut confirmed_commitment_tx_counterparty_output = None;
4019                 let mut spendable_txids_confirmed = Some(Vec::new());
4020                 let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
4021                 read_tlv_fields!(reader, {
4022                         (1, funding_spend_confirmed, option),
4023                         (3, htlcs_resolved_on_chain, vec_type),
4024                         (5, pending_monitor_events, vec_type),
4025                         (7, funding_spend_seen, option),
4026                         (9, counterparty_node_id, option),
4027                         (11, confirmed_commitment_tx_counterparty_output, option),
4028                         (13, spendable_txids_confirmed, vec_type),
4029                         (15, counterparty_fulfilled_htlcs, option),
4030                 });
4031
4032                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
4033                         latest_update_id,
4034                         commitment_transaction_number_obscure_factor,
4035
4036                         destination_script,
4037                         broadcasted_holder_revokable_script,
4038                         counterparty_payment_script,
4039                         shutdown_script,
4040
4041                         channel_keys_id,
4042                         holder_revocation_basepoint,
4043                         funding_info,
4044                         current_counterparty_commitment_txid,
4045                         prev_counterparty_commitment_txid,
4046
4047                         counterparty_commitment_params,
4048                         funding_redeemscript,
4049                         channel_value_satoshis,
4050                         their_cur_per_commitment_points,
4051
4052                         on_holder_tx_csv,
4053
4054                         commitment_secrets,
4055                         counterparty_claimable_outpoints,
4056                         counterparty_commitment_txn_on_chain,
4057                         counterparty_hash_commitment_number,
4058                         counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
4059
4060                         prev_holder_signed_commitment_tx,
4061                         current_holder_commitment_tx,
4062                         current_counterparty_commitment_number,
4063                         current_holder_commitment_number,
4064
4065                         payment_preimages,
4066                         pending_monitor_events: pending_monitor_events.unwrap(),
4067                         pending_events,
4068
4069                         onchain_events_awaiting_threshold_conf,
4070                         outputs_to_watch,
4071
4072                         onchain_tx_handler,
4073
4074                         lockdown_from_offchain,
4075                         holder_tx_signed,
4076                         funding_spend_seen: funding_spend_seen.unwrap(),
4077                         funding_spend_confirmed,
4078                         confirmed_commitment_tx_counterparty_output,
4079                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
4080                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
4081
4082                         best_block,
4083                         counterparty_node_id,
4084                 })))
4085         }
4086 }
4087
4088 #[cfg(test)]
4089 mod tests {
4090         use bitcoin::blockdata::script::{Script, Builder};
4091         use bitcoin::blockdata::opcodes;
4092         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
4093         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
4094         use bitcoin::util::sighash;
4095         use bitcoin::hashes::Hash;
4096         use bitcoin::hashes::sha256::Hash as Sha256;
4097         use bitcoin::hashes::hex::FromHex;
4098         use bitcoin::hash_types::{BlockHash, Txid};
4099         use bitcoin::network::constants::Network;
4100         use bitcoin::secp256k1::{SecretKey,PublicKey};
4101         use bitcoin::secp256k1::Secp256k1;
4102
4103         use hex;
4104
4105         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
4106
4107         use super::ChannelMonitorUpdateStep;
4108         use crate::{check_added_monitors, check_closed_broadcast, check_closed_event, check_spends, get_local_commitment_txn, get_monitor, get_route_and_payment_hash, unwrap_send_err};
4109         use crate::chain::{BestBlock, Confirm};
4110         use crate::chain::channelmonitor::ChannelMonitor;
4111         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
4112         use crate::chain::transaction::OutPoint;
4113         use crate::sign::InMemorySigner;
4114         use crate::events::ClosureReason;
4115         use crate::ln::{PaymentPreimage, PaymentHash};
4116         use crate::ln::chan_utils;
4117         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
4118         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId, RecipientOnionFields};
4119         use crate::ln::functional_test_utils::*;
4120         use crate::ln::script::ShutdownScript;
4121         use crate::util::errors::APIError;
4122         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
4123         use crate::util::ser::{ReadableArgs, Writeable};
4124         use crate::sync::{Arc, Mutex};
4125         use crate::io;
4126         use bitcoin::{PackedLockTime, Sequence, Witness};
4127         use crate::prelude::*;
4128
4129         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
4130                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
4131                 // confirmed. This would allow a race condition where we could receive a payment (including
4132                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
4133                 // long as the ChannelMonitor receives the block first, the full commitment update dance
4134                 // occurs after the block is connected, and before the ChannelManager receives the block.
4135                 // Obviously this is an incredibly contrived race given the counterparty would be risking
4136                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
4137                 // potential ChannelMonitor states simpler to reason about.
4138                 //
4139                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
4140                 // updates is handled correctly in such conditions.
4141                 let chanmon_cfgs = create_chanmon_cfgs(3);
4142                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
4143                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
4144                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
4145                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
4146                 create_announced_chan_between_nodes(&nodes, 1, 2);
4147
4148                 // Rebalance somewhat
4149                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
4150
4151                 // First route two payments for testing at the end
4152                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4153                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4154
4155                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4156                 assert_eq!(local_txn.len(), 1);
4157                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4158                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4159                 check_spends!(remote_txn[1], remote_txn[0]);
4160                 check_spends!(remote_txn[2], remote_txn[0]);
4161                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4162
4163                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4164                 // channel is now closed, but the ChannelManager doesn't know that yet.
4165                 let new_header = create_dummy_header(nodes[0].best_block_info().0, 0);
4166                 let conf_height = nodes[0].best_block_info().1 + 1;
4167                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4168                         &[(0, broadcast_tx)], conf_height);
4169
4170                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4171                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4172                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4173
4174                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4175                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4176                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4177                 unwrap_send_err!(nodes[1].node.send_payment_with_route(&route, payment_hash,
4178                                 RecipientOnionFields::secret_only(payment_secret), PaymentId(payment_hash.0)
4179                         ), true, APIError::ChannelUnavailable { ref err },
4180                         assert!(err.contains("ChannelMonitor storage failure")));
4181                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
4182                 check_closed_broadcast!(nodes[1], true);
4183                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
4184
4185                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4186                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4187                 // an error, but the point of this test is to ensure the later updates are still applied.
4188                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4189                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
4190                 assert_eq!(replay_update.updates.len(), 1);
4191                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4192                 } else { panic!(); }
4193                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4194                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4195
4196                 let broadcaster = TestBroadcaster::with_blocks(Arc::clone(&nodes[1].blocks));
4197                 assert!(
4198                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4199                         .is_err());
4200                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4201                 // transaction
4202                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4203                 assert!(txn_broadcasted.len() >= 2);
4204                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4205                         assert_eq!(tx.input.len(), 1);
4206                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4207                 }).collect::<Vec<_>>();
4208                 assert_eq!(htlc_txn.len(), 2);
4209                 check_spends!(htlc_txn[0], broadcast_tx);
4210                 check_spends!(htlc_txn[1], broadcast_tx);
4211         }
4212         #[test]
4213         fn test_funding_spend_refuses_updates() {
4214                 do_test_funding_spend_refuses_updates(true);
4215                 do_test_funding_spend_refuses_updates(false);
4216         }
4217
4218         #[test]
4219         fn test_prune_preimages() {
4220                 let secp_ctx = Secp256k1::new();
4221                 let logger = Arc::new(TestLogger::new());
4222                 let broadcaster = Arc::new(TestBroadcaster::new(Network::Testnet));
4223                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4224
4225                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4226
4227                 let mut preimages = Vec::new();
4228                 {
4229                         for i in 0..20 {
4230                                 let preimage = PaymentPreimage([i; 32]);
4231                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4232                                 preimages.push((preimage, hash));
4233                         }
4234                 }
4235
4236                 macro_rules! preimages_slice_to_htlcs {
4237                         ($preimages_slice: expr) => {
4238                                 {
4239                                         let mut res = Vec::new();
4240                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4241                                                 res.push((HTLCOutputInCommitment {
4242                                                         offered: true,
4243                                                         amount_msat: 0,
4244                                                         cltv_expiry: 0,
4245                                                         payment_hash: preimage.1.clone(),
4246                                                         transaction_output_index: Some(idx as u32),
4247                                                 }, ()));
4248                                         }
4249                                         res
4250                                 }
4251                         }
4252                 }
4253                 macro_rules! preimages_slice_to_htlc_outputs {
4254                         ($preimages_slice: expr) => {
4255                                 preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect()
4256                         }
4257                 }
4258                 let dummy_sig = crate::util::crypto::sign(&secp_ctx,
4259                         &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(),
4260                         &SecretKey::from_slice(&[42; 32]).unwrap());
4261
4262                 macro_rules! test_preimages_exist {
4263                         ($preimages_slice: expr, $monitor: expr) => {
4264                                 for preimage in $preimages_slice {
4265                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4266                                 }
4267                         }
4268                 }
4269
4270                 let keys = InMemorySigner::new(
4271                         &secp_ctx,
4272                         SecretKey::from_slice(&[41; 32]).unwrap(),
4273                         SecretKey::from_slice(&[41; 32]).unwrap(),
4274                         SecretKey::from_slice(&[41; 32]).unwrap(),
4275                         SecretKey::from_slice(&[41; 32]).unwrap(),
4276                         SecretKey::from_slice(&[41; 32]).unwrap(),
4277                         [41; 32],
4278                         0,
4279                         [0; 32],
4280                         [0; 32],
4281                 );
4282
4283                 let counterparty_pubkeys = ChannelPublicKeys {
4284                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4285                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4286                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4287                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4288                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4289                 };
4290                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4291                 let channel_parameters = ChannelTransactionParameters {
4292                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4293                         holder_selected_contest_delay: 66,
4294                         is_outbound_from_holder: true,
4295                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4296                                 pubkeys: counterparty_pubkeys,
4297                                 selected_contest_delay: 67,
4298                         }),
4299                         funding_outpoint: Some(funding_outpoint),
4300                         opt_anchors: None,
4301                         opt_non_zero_fee_anchors: None,
4302                 };
4303                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4304                 // old state.
4305                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4306                 let best_block = BestBlock::from_network(Network::Testnet);
4307                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4308                         Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4309                         (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4310                         &channel_parameters, Script::new(), 46, 0, HolderCommitmentTransaction::dummy(&mut Vec::new()),
4311                         best_block, dummy_key);
4312
4313                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..10]);
4314                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4315                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
4316                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4317                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
4318                         preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4319                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
4320                         preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4321                 for &(ref preimage, ref hash) in preimages.iter() {
4322                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4323                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4324                 }
4325
4326                 // Now provide a secret, pruning preimages 10-15
4327                 let mut secret = [0; 32];
4328                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4329                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4330                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4331                 test_preimages_exist!(&preimages[0..10], monitor);
4332                 test_preimages_exist!(&preimages[15..20], monitor);
4333
4334                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
4335                         preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4336
4337                 // Now provide a further secret, pruning preimages 15-17
4338                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4339                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4340                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4341                 test_preimages_exist!(&preimages[0..10], monitor);
4342                 test_preimages_exist!(&preimages[17..20], monitor);
4343
4344                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
4345                         preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4346
4347                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4348                 // previous commitment tx's preimages too
4349                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..5]);
4350                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4351                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
4352                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4353                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4354                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4355                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4356                 test_preimages_exist!(&preimages[0..10], monitor);
4357                 test_preimages_exist!(&preimages[18..20], monitor);
4358
4359                 // But if we do it again, we'll prune 5-10
4360                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..3]);
4361                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4362                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx,
4363                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4364                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4365                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4366                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4367                 test_preimages_exist!(&preimages[0..5], monitor);
4368         }
4369
4370         #[test]
4371         fn test_claim_txn_weight_computation() {
4372                 // We test Claim txn weight, knowing that we want expected weigth and
4373                 // not actual case to avoid sigs and time-lock delays hell variances.
4374
4375                 let secp_ctx = Secp256k1::new();
4376                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4377                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4378
4379                 macro_rules! sign_input {
4380                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4381                                 let htlc = HTLCOutputInCommitment {
4382                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4383                                         amount_msat: 0,
4384                                         cltv_expiry: 2 << 16,
4385                                         payment_hash: PaymentHash([1; 32]),
4386                                         transaction_output_index: Some($idx as u32),
4387                                 };
4388                                 let redeem_script = if *$weight == WEIGHT_REVOKED_OUTPUT { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4389                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4390                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4391                                 let mut ser_sig = sig.serialize_der().to_vec();
4392                                 ser_sig.push(EcdsaSighashType::All as u8);
4393                                 $sum_actual_sigs += ser_sig.len();
4394                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4395                                 witness.push(ser_sig);
4396                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4397                                         witness.push(vec!(1));
4398                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4399                                         witness.push(pubkey.clone().serialize().to_vec());
4400                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4401                                         witness.push(vec![0]);
4402                                 } else {
4403                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4404                                 }
4405                                 witness.push(redeem_script.into_bytes());
4406                                 let witness = witness.to_vec();
4407                                 println!("witness[0] {}", witness[0].len());
4408                                 println!("witness[1] {}", witness[1].len());
4409                                 println!("witness[2] {}", witness[2].len());
4410                         }
4411                 }
4412
4413                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4414                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4415
4416                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4417                 for &opt_anchors in [false, true].iter() {
4418                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4419                         let mut sum_actual_sigs = 0;
4420                         for i in 0..4 {
4421                                 claim_tx.input.push(TxIn {
4422                                         previous_output: BitcoinOutPoint {
4423                                                 txid,
4424                                                 vout: i,
4425                                         },
4426                                         script_sig: Script::new(),
4427                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4428                                         witness: Witness::new(),
4429                                 });
4430                         }
4431                         claim_tx.output.push(TxOut {
4432                                 script_pubkey: script_pubkey.clone(),
4433                                 value: 0,
4434                         });
4435                         let base_weight = claim_tx.weight();
4436                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(opt_anchors), weight_revoked_offered_htlc(opt_anchors), weight_revoked_received_htlc(opt_anchors)];
4437                         let mut inputs_total_weight = 2; // count segwit flags
4438                         {
4439                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4440                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4441                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4442                                         inputs_total_weight += inp;
4443                                 }
4444                         }
4445                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4446                 }
4447
4448                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4449                 for &opt_anchors in [false, true].iter() {
4450                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4451                         let mut sum_actual_sigs = 0;
4452                         for i in 0..4 {
4453                                 claim_tx.input.push(TxIn {
4454                                         previous_output: BitcoinOutPoint {
4455                                                 txid,
4456                                                 vout: i,
4457                                         },
4458                                         script_sig: Script::new(),
4459                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4460                                         witness: Witness::new(),
4461                                 });
4462                         }
4463                         claim_tx.output.push(TxOut {
4464                                 script_pubkey: script_pubkey.clone(),
4465                                 value: 0,
4466                         });
4467                         let base_weight = claim_tx.weight();
4468                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
4469                         let mut inputs_total_weight = 2; // count segwit flags
4470                         {
4471                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4472                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4473                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4474                                         inputs_total_weight += inp;
4475                                 }
4476                         }
4477                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4478                 }
4479
4480                 // Justice tx with 1 revoked HTLC-Success tx output
4481                 for &opt_anchors in [false, true].iter() {
4482                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4483                         let mut sum_actual_sigs = 0;
4484                         claim_tx.input.push(TxIn {
4485                                 previous_output: BitcoinOutPoint {
4486                                         txid,
4487                                         vout: 0,
4488                                 },
4489                                 script_sig: Script::new(),
4490                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4491                                 witness: Witness::new(),
4492                         });
4493                         claim_tx.output.push(TxOut {
4494                                 script_pubkey: script_pubkey.clone(),
4495                                 value: 0,
4496                         });
4497                         let base_weight = claim_tx.weight();
4498                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4499                         let mut inputs_total_weight = 2; // count segwit flags
4500                         {
4501                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4502                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4503                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
4504                                         inputs_total_weight += inp;
4505                                 }
4506                         }
4507                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4508                 }
4509         }
4510
4511         // Further testing is done in the ChannelManager integration tests.
4512 }