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[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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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, EcdsaSighashType};
35
36 use crate::ln::channel::INITIAL_COMMITMENT_NUMBER;
37 use crate::ln::{PaymentHash, PaymentPreimage};
38 use crate::ln::msgs::DecodeError;
39 use crate::ln::chan_utils;
40 use crate::ln::chan_utils::{CommitmentTransaction, CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCClaim, ChannelTransactionParameters, HolderCommitmentTransaction, TxCreationKeys};
41 use crate::ln::channelmanager::{HTLCSource, SentHTLCId};
42 use crate::chain;
43 use crate::chain::{BestBlock, WatchedOutput};
44 use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator};
45 use crate::chain::transaction::{OutPoint, TransactionData};
46 use crate::sign::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource};
47 use crate::chain::onchaintx::{ClaimEvent, OnchainTxHandler};
48 use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
49 use crate::chain::Filter;
50 use crate::util::logger::Logger;
51 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48};
52 use crate::util::byte_utils;
53 use crate::events::{Event, EventHandler};
54 use crate::events::bump_transaction::{ChannelDerivationParameters, AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent};
55
56 use crate::prelude::*;
57 use core::{cmp, mem};
58 use crate::io::{self, Error};
59 use core::convert::TryInto;
60 use core::ops::Deref;
61 use crate::sync::{Mutex, LockTestExt};
62
63 /// An update generated by the underlying channel itself which contains some new information the
64 /// [`ChannelMonitor`] should be made aware of.
65 ///
66 /// Because this represents only a small number of updates to the underlying state, it is generally
67 /// much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
68 /// updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
69 /// transaction), a single update may reach upwards of 1 MiB in serialized size.
70 #[derive(Clone, Debug, PartialEq, Eq)]
71 #[must_use]
72 pub struct ChannelMonitorUpdate {
73         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
74         /// The sequence number of this update. Updates *must* be replayed in-order according to this
75         /// sequence number (and updates may panic if they are not). The update_id values are strictly
76         /// increasing and increase by one for each new update, with two exceptions specified below.
77         ///
78         /// This sequence number is also used to track up to which points updates which returned
79         /// [`ChannelMonitorUpdateStatus::InProgress`] have been applied to all copies of a given
80         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
81         ///
82         /// The only instances we allow where update_id values are not strictly increasing have a
83         /// special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. This update ID is used for updates that
84         /// will force close the channel by broadcasting the latest commitment transaction or
85         /// special post-force-close updates, like providing preimages necessary to claim outputs on the
86         /// broadcast commitment transaction. See its docs for more details.
87         ///
88         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
89         pub update_id: u64,
90 }
91
92 /// The update ID used for a [`ChannelMonitorUpdate`] that is either:
93 ///
94 ///     (1) attempting to force close the channel by broadcasting our latest commitment transaction or
95 ///     (2) providing a preimage (after the channel has been force closed) from a forward link that
96 ///             allows us to spend an HTLC output on this channel's (the backward link's) broadcasted
97 ///             commitment transaction.
98 ///
99 /// No other [`ChannelMonitorUpdate`]s are allowed after force-close.
100 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
101
102 impl Writeable for ChannelMonitorUpdate {
103         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
104                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
105                 self.update_id.write(w)?;
106                 (self.updates.len() as u64).write(w)?;
107                 for update_step in self.updates.iter() {
108                         update_step.write(w)?;
109                 }
110                 write_tlv_fields!(w, {});
111                 Ok(())
112         }
113 }
114 impl Readable for ChannelMonitorUpdate {
115         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
116                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
117                 let update_id: u64 = Readable::read(r)?;
118                 let len: u64 = Readable::read(r)?;
119                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
120                 for _ in 0..len {
121                         if let Some(upd) = MaybeReadable::read(r)? {
122                                 updates.push(upd);
123                         }
124                 }
125                 read_tlv_fields!(r, {});
126                 Ok(Self { update_id, updates })
127         }
128 }
129
130 /// An event to be processed by the ChannelManager.
131 #[derive(Clone, PartialEq, Eq)]
132 pub enum MonitorEvent {
133         /// A monitor event containing an HTLCUpdate.
134         HTLCEvent(HTLCUpdate),
135
136         /// A monitor event that the Channel's commitment transaction was confirmed.
137         HolderForceClosed(OutPoint),
138
139         /// Indicates a [`ChannelMonitor`] update has completed. See
140         /// [`ChannelMonitorUpdateStatus::InProgress`] for more information on how this is used.
141         ///
142         /// [`ChannelMonitorUpdateStatus::InProgress`]: super::ChannelMonitorUpdateStatus::InProgress
143         Completed {
144                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
145                 funding_txo: OutPoint,
146                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
147                 /// [`ChannelMonitor::get_latest_update_id`].
148                 ///
149                 /// Note that this should only be set to a given update's ID if all previous updates for the
150                 /// same [`ChannelMonitor`] have been applied and persisted.
151                 monitor_update_id: u64,
152         },
153 }
154 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
155         // Note that Completed is currently never serialized to disk as it is generated only in
156         // ChainMonitor.
157         (0, Completed) => {
158                 (0, funding_txo, required),
159                 (2, monitor_update_id, required),
160         },
161 ;
162         (2, HTLCEvent),
163         (4, HolderForceClosed),
164         // 6 was `UpdateFailed` until LDK 0.0.117
165 );
166
167 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
168 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
169 /// preimage claim backward will lead to loss of funds.
170 #[derive(Clone, PartialEq, Eq)]
171 pub struct HTLCUpdate {
172         pub(crate) payment_hash: PaymentHash,
173         pub(crate) payment_preimage: Option<PaymentPreimage>,
174         pub(crate) source: HTLCSource,
175         pub(crate) htlc_value_satoshis: Option<u64>,
176 }
177 impl_writeable_tlv_based!(HTLCUpdate, {
178         (0, payment_hash, required),
179         (1, htlc_value_satoshis, option),
180         (2, source, required),
181         (4, payment_preimage, option),
182 });
183
184 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
185 /// instead claiming it in its own individual transaction.
186 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
187 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
188 /// HTLC-Success transaction.
189 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
190 /// transaction confirmed (and we use it in a few more, equivalent, places).
191 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
192 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
193 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
194 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
195 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
196 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
197 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
198 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
199 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
200 /// accurate block height.
201 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
202 /// with at worst this delay, so we are not only using this value as a mercy for them but also
203 /// us as a safeguard to delay with enough time.
204 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
205 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
206 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
207 /// losing money.
208 ///
209 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
210 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
211 /// by a  [`ChannelMonitor`] may be incorrect.
212 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
213 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
214 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
215 // keep bumping another claim tx to solve the outpoint.
216 pub const ANTI_REORG_DELAY: u32 = 6;
217 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
218 /// refuse to accept a new HTLC.
219 ///
220 /// This is used for a few separate purposes:
221 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
222 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
223 ///    fail this HTLC,
224 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
225 ///    condition with the above), we will fail this HTLC without telling the user we received it,
226 ///
227 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
228 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
229 ///
230 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
231 /// in a race condition between the user connecting a block (which would fail it) and the user
232 /// providing us the preimage (which would claim it).
233 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
234
235 // TODO(devrandom) replace this with HolderCommitmentTransaction
236 #[derive(Clone, PartialEq, Eq)]
237 struct HolderSignedTx {
238         /// txid of the transaction in tx, just used to make comparison faster
239         txid: Txid,
240         revocation_key: PublicKey,
241         a_htlc_key: PublicKey,
242         b_htlc_key: PublicKey,
243         delayed_payment_key: PublicKey,
244         per_commitment_point: PublicKey,
245         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
246         to_self_value_sat: u64,
247         feerate_per_kw: u32,
248 }
249 impl_writeable_tlv_based!(HolderSignedTx, {
250         (0, txid, required),
251         // Note that this is filled in with data from OnchainTxHandler if it's missing.
252         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
253         (1, to_self_value_sat, (default_value, u64::max_value())),
254         (2, revocation_key, required),
255         (4, a_htlc_key, required),
256         (6, b_htlc_key, required),
257         (8, delayed_payment_key, required),
258         (10, per_commitment_point, required),
259         (12, feerate_per_kw, required),
260         (14, htlc_outputs, required_vec)
261 });
262
263 impl HolderSignedTx {
264         fn non_dust_htlcs(&self) -> Vec<HTLCOutputInCommitment> {
265                 self.htlc_outputs.iter().filter_map(|(htlc, _, _)| {
266                         if let Some(_) = htlc.transaction_output_index {
267                                 Some(htlc.clone())
268                         } else {
269                                 None
270                         }
271                 })
272                 .collect()
273         }
274 }
275
276 /// We use this to track static counterparty commitment transaction data and to generate any
277 /// justice or 2nd-stage preimage/timeout transactions.
278 #[derive(Clone, PartialEq, Eq)]
279 struct CounterpartyCommitmentParameters {
280         counterparty_delayed_payment_base_key: PublicKey,
281         counterparty_htlc_base_key: PublicKey,
282         on_counterparty_tx_csv: u16,
283 }
284
285 impl Writeable for CounterpartyCommitmentParameters {
286         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
287                 w.write_all(&(0 as u64).to_be_bytes())?;
288                 write_tlv_fields!(w, {
289                         (0, self.counterparty_delayed_payment_base_key, required),
290                         (2, self.counterparty_htlc_base_key, required),
291                         (4, self.on_counterparty_tx_csv, required),
292                 });
293                 Ok(())
294         }
295 }
296 impl Readable for CounterpartyCommitmentParameters {
297         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
298                 let counterparty_commitment_transaction = {
299                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
300                         // used. Read it for compatibility.
301                         let per_htlc_len: u64 = Readable::read(r)?;
302                         for _  in 0..per_htlc_len {
303                                 let _txid: Txid = Readable::read(r)?;
304                                 let htlcs_count: u64 = Readable::read(r)?;
305                                 for _ in 0..htlcs_count {
306                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
307                                 }
308                         }
309
310                         let mut counterparty_delayed_payment_base_key = RequiredWrapper(None);
311                         let mut counterparty_htlc_base_key = RequiredWrapper(None);
312                         let mut on_counterparty_tx_csv: u16 = 0;
313                         read_tlv_fields!(r, {
314                                 (0, counterparty_delayed_payment_base_key, required),
315                                 (2, counterparty_htlc_base_key, required),
316                                 (4, on_counterparty_tx_csv, required),
317                         });
318                         CounterpartyCommitmentParameters {
319                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
320                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
321                                 on_counterparty_tx_csv,
322                         }
323                 };
324                 Ok(counterparty_commitment_transaction)
325         }
326 }
327
328 /// An entry for an [`OnchainEvent`], stating the block height and hash when the event was
329 /// observed, as well as the transaction causing it.
330 ///
331 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
332 #[derive(Clone, PartialEq, Eq)]
333 struct OnchainEventEntry {
334         txid: Txid,
335         height: u32,
336         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
337         event: OnchainEvent,
338         transaction: Option<Transaction>, // Added as optional, but always filled in, in LDK 0.0.110
339 }
340
341 impl OnchainEventEntry {
342         fn confirmation_threshold(&self) -> u32 {
343                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
344                 match self.event {
345                         OnchainEvent::MaturingOutput {
346                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
347                         } => {
348                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
349                                 // it's broadcastable when we see the previous block.
350                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
351                         },
352                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
353                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
354                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
355                                 // it's broadcastable when we see the previous block.
356                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
357                         },
358                         _ => {},
359                 }
360                 conf_threshold
361         }
362
363         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
364                 best_block.height() >= self.confirmation_threshold()
365         }
366 }
367
368 /// The (output index, sats value) for the counterparty's output in a commitment transaction.
369 ///
370 /// This was added as an `Option` in 0.0.110.
371 type CommitmentTxCounterpartyOutputInfo = Option<(u32, u64)>;
372
373 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
374 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
375 #[derive(Clone, PartialEq, Eq)]
376 enum OnchainEvent {
377         /// An outbound HTLC failing after a transaction is confirmed. Used
378         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
379         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
380         ///    on-chain (either because it was not fully committed to or it was dust).
381         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
382         /// appearing only as an `HTLCSpendConfirmation`, below.
383         HTLCUpdate {
384                 source: HTLCSource,
385                 payment_hash: PaymentHash,
386                 htlc_value_satoshis: Option<u64>,
387                 /// None in the second case, above, ie when there is no relevant output in the commitment
388                 /// transaction which appeared on chain.
389                 commitment_tx_output_idx: Option<u32>,
390         },
391         /// An output waiting on [`ANTI_REORG_DELAY`] confirmations before we hand the user the
392         /// [`SpendableOutputDescriptor`].
393         MaturingOutput {
394                 descriptor: SpendableOutputDescriptor,
395         },
396         /// A spend of the funding output, either a commitment transaction or a cooperative closing
397         /// transaction.
398         FundingSpendConfirmation {
399                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
400                 /// commitment transaction, and this is the delay on the to_self output).
401                 on_local_output_csv: Option<u16>,
402                 /// If the funding spend transaction was a known remote commitment transaction, we track
403                 /// the output index and amount of the counterparty's `to_self` output here.
404                 ///
405                 /// This allows us to generate a [`Balance::CounterpartyRevokedOutputClaimable`] for the
406                 /// counterparty output.
407                 commitment_tx_to_counterparty_output: CommitmentTxCounterpartyOutputInfo,
408         },
409         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
410         /// is constructed. This is used when
411         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
412         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
413         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
414         ///  * an inbound HTLC is claimed by us (with a preimage).
415         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
416         ///    signature.
417         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by an
418         ///    HTLC-Success/HTLC-Failure transaction (and is still claimable with a revocation
419         ///    signature).
420         HTLCSpendConfirmation {
421                 commitment_tx_output_idx: u32,
422                 /// If the claim was made by either party with a preimage, this is filled in
423                 preimage: Option<PaymentPreimage>,
424                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
425                 /// we set this to the output CSV value which we will have to wait until to spend the
426                 /// output (and generate a SpendableOutput event).
427                 on_to_local_output_csv: Option<u16>,
428         },
429 }
430
431 impl Writeable for OnchainEventEntry {
432         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
433                 write_tlv_fields!(writer, {
434                         (0, self.txid, required),
435                         (1, self.transaction, option),
436                         (2, self.height, required),
437                         (3, self.block_hash, option),
438                         (4, self.event, required),
439                 });
440                 Ok(())
441         }
442 }
443
444 impl MaybeReadable for OnchainEventEntry {
445         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
446                 let mut txid = Txid::all_zeros();
447                 let mut transaction = None;
448                 let mut block_hash = None;
449                 let mut height = 0;
450                 let mut event = UpgradableRequired(None);
451                 read_tlv_fields!(reader, {
452                         (0, txid, required),
453                         (1, transaction, option),
454                         (2, height, required),
455                         (3, block_hash, option),
456                         (4, event, upgradable_required),
457                 });
458                 Ok(Some(Self { txid, transaction, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
459         }
460 }
461
462 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
463         (0, HTLCUpdate) => {
464                 (0, source, required),
465                 (1, htlc_value_satoshis, option),
466                 (2, payment_hash, required),
467                 (3, commitment_tx_output_idx, option),
468         },
469         (1, MaturingOutput) => {
470                 (0, descriptor, required),
471         },
472         (3, FundingSpendConfirmation) => {
473                 (0, on_local_output_csv, option),
474                 (1, commitment_tx_to_counterparty_output, option),
475         },
476         (5, HTLCSpendConfirmation) => {
477                 (0, commitment_tx_output_idx, required),
478                 (2, preimage, option),
479                 (4, on_to_local_output_csv, option),
480         },
481
482 );
483
484 #[derive(Clone, Debug, PartialEq, Eq)]
485 pub(crate) enum ChannelMonitorUpdateStep {
486         LatestHolderCommitmentTXInfo {
487                 commitment_tx: HolderCommitmentTransaction,
488                 /// Note that LDK after 0.0.115 supports this only containing dust HTLCs (implying the
489                 /// `Signature` field is never filled in). At that point, non-dust HTLCs are implied by the
490                 /// HTLC fields in `commitment_tx` and the sources passed via `nondust_htlc_sources`.
491                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
492                 claimed_htlcs: Vec<(SentHTLCId, PaymentPreimage)>,
493                 nondust_htlc_sources: Vec<HTLCSource>,
494         },
495         LatestCounterpartyCommitmentTXInfo {
496                 commitment_txid: Txid,
497                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
498                 commitment_number: u64,
499                 their_per_commitment_point: PublicKey,
500                 feerate_per_kw: Option<u32>,
501                 to_broadcaster_value_sat: Option<u64>,
502                 to_countersignatory_value_sat: Option<u64>,
503         },
504         PaymentPreimage {
505                 payment_preimage: PaymentPreimage,
506         },
507         CommitmentSecret {
508                 idx: u64,
509                 secret: [u8; 32],
510         },
511         /// Used to indicate that the no future updates will occur, and likely that the latest holder
512         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
513         ChannelForceClosed {
514                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
515                 /// think we've fallen behind!
516                 should_broadcast: bool,
517         },
518         ShutdownScript {
519                 scriptpubkey: Script,
520         },
521 }
522
523 impl ChannelMonitorUpdateStep {
524         fn variant_name(&self) -> &'static str {
525                 match self {
526                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
527                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
528                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
529                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
530                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
531                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
532                 }
533         }
534 }
535
536 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
537         (0, LatestHolderCommitmentTXInfo) => {
538                 (0, commitment_tx, required),
539                 (1, claimed_htlcs, optional_vec),
540                 (2, htlc_outputs, required_vec),
541                 (4, nondust_htlc_sources, optional_vec),
542         },
543         (1, LatestCounterpartyCommitmentTXInfo) => {
544                 (0, commitment_txid, required),
545                 (1, feerate_per_kw, option),
546                 (2, commitment_number, required),
547                 (3, to_broadcaster_value_sat, option),
548                 (4, their_per_commitment_point, required),
549                 (5, to_countersignatory_value_sat, option),
550                 (6, htlc_outputs, required_vec),
551         },
552         (2, PaymentPreimage) => {
553                 (0, payment_preimage, required),
554         },
555         (3, CommitmentSecret) => {
556                 (0, idx, required),
557                 (2, secret, required),
558         },
559         (4, ChannelForceClosed) => {
560                 (0, should_broadcast, required),
561         },
562         (5, ShutdownScript) => {
563                 (0, scriptpubkey, required),
564         },
565 );
566
567 /// Details about the balance(s) available for spending once the channel appears on chain.
568 ///
569 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
570 /// be provided.
571 #[derive(Clone, Debug, PartialEq, Eq)]
572 #[cfg_attr(test, derive(PartialOrd, Ord))]
573 pub enum Balance {
574         /// The channel is not yet closed (or the commitment or closing transaction has not yet
575         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
576         /// force-closed now.
577         ClaimableOnChannelClose {
578                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
579                 /// required to do so.
580                 amount_satoshis: u64,
581         },
582         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
583         /// we consider it spendable.
584         ClaimableAwaitingConfirmations {
585                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
586                 /// were spent in broadcasting the transaction.
587                 amount_satoshis: u64,
588                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
589                 /// amount.
590                 confirmation_height: u32,
591         },
592         /// The channel has been closed, and the given balance should be ours but awaiting spending
593         /// transaction confirmation. If the spending transaction does not confirm in time, it is
594         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
595         ///
596         /// Once the spending transaction confirms, before it has reached enough confirmations to be
597         /// considered safe from chain reorganizations, the balance will instead be provided via
598         /// [`Balance::ClaimableAwaitingConfirmations`].
599         ContentiousClaimable {
600                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
601                 /// required to do so.
602                 amount_satoshis: u64,
603                 /// The height at which the counterparty may be able to claim the balance if we have not
604                 /// done so.
605                 timeout_height: u32,
606                 /// The payment hash that locks this HTLC.
607                 payment_hash: PaymentHash,
608                 /// The preimage that can be used to claim this HTLC.
609                 payment_preimage: PaymentPreimage,
610         },
611         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
612         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
613         /// likely to be claimed by our counterparty before we do.
614         MaybeTimeoutClaimableHTLC {
615                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
616                 /// which will be required to do so.
617                 amount_satoshis: u64,
618                 /// The height at which we will be able to claim the balance if our counterparty has not
619                 /// done so.
620                 claimable_height: u32,
621                 /// The payment hash whose preimage our counterparty needs to claim this HTLC.
622                 payment_hash: PaymentHash,
623         },
624         /// HTLCs which we received from our counterparty which are claimable with a preimage which we
625         /// do not currently have. This will only be claimable if we receive the preimage from the node
626         /// to which we forwarded this HTLC before the timeout.
627         MaybePreimageClaimableHTLC {
628                 /// The amount potentially available to claim, in satoshis, excluding the on-chain fees
629                 /// which will be required to do so.
630                 amount_satoshis: u64,
631                 /// The height at which our counterparty will be able to claim the balance if we have not
632                 /// yet received the preimage and claimed it ourselves.
633                 expiry_height: u32,
634                 /// The payment hash whose preimage we need to claim this HTLC.
635                 payment_hash: PaymentHash,
636         },
637         /// The channel has been closed, and our counterparty broadcasted a revoked commitment
638         /// transaction.
639         ///
640         /// Thus, we're able to claim all outputs in the commitment transaction, one of which has the
641         /// following amount.
642         CounterpartyRevokedOutputClaimable {
643                 /// The amount, in satoshis, of the output which we can claim.
644                 ///
645                 /// Note that for outputs from HTLC balances this may be excluding some on-chain fees that
646                 /// were already spent.
647                 amount_satoshis: u64,
648         },
649 }
650
651 impl Balance {
652         /// The amount claimable, in satoshis. This excludes balances that we are unsure if we are able
653         /// to claim, this is because we are waiting for a preimage or for a timeout to expire. For more
654         /// information on these balances see [`Balance::MaybeTimeoutClaimableHTLC`] and
655         /// [`Balance::MaybePreimageClaimableHTLC`].
656         ///
657         /// On-chain fees required to claim the balance are not included in this amount.
658         pub fn claimable_amount_satoshis(&self) -> u64 {
659                 match self {
660                         Balance::ClaimableOnChannelClose { amount_satoshis, .. }|
661                         Balance::ClaimableAwaitingConfirmations { amount_satoshis, .. }|
662                         Balance::ContentiousClaimable { amount_satoshis, .. }|
663                         Balance::CounterpartyRevokedOutputClaimable { amount_satoshis, .. }
664                                 => *amount_satoshis,
665                         Balance::MaybeTimeoutClaimableHTLC { .. }|
666                         Balance::MaybePreimageClaimableHTLC { .. }
667                                 => 0,
668                 }
669         }
670 }
671
672 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
673 #[derive(Clone, PartialEq, Eq)]
674 struct IrrevocablyResolvedHTLC {
675         commitment_tx_output_idx: Option<u32>,
676         /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
677         /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
678         /// transaction.
679         resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
680         resolving_tx: Option<Transaction>,
681         /// Only set if the HTLC claim was ours using a payment preimage
682         payment_preimage: Option<PaymentPreimage>,
683 }
684
685 // In LDK versions prior to 0.0.111 commitment_tx_output_idx was not Option-al and
686 // IrrevocablyResolvedHTLC objects only existed for non-dust HTLCs. This was a bug, but to maintain
687 // backwards compatibility we must ensure we always write out a commitment_tx_output_idx field,
688 // using `u32::max_value()` as a sentinal to indicate the HTLC was dust.
689 impl Writeable for IrrevocablyResolvedHTLC {
690         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
691                 let mapped_commitment_tx_output_idx = self.commitment_tx_output_idx.unwrap_or(u32::max_value());
692                 write_tlv_fields!(writer, {
693                         (0, mapped_commitment_tx_output_idx, required),
694                         (1, self.resolving_txid, option),
695                         (2, self.payment_preimage, option),
696                         (3, self.resolving_tx, option),
697                 });
698                 Ok(())
699         }
700 }
701
702 impl Readable for IrrevocablyResolvedHTLC {
703         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
704                 let mut mapped_commitment_tx_output_idx = 0;
705                 let mut resolving_txid = None;
706                 let mut payment_preimage = None;
707                 let mut resolving_tx = None;
708                 read_tlv_fields!(reader, {
709                         (0, mapped_commitment_tx_output_idx, required),
710                         (1, resolving_txid, option),
711                         (2, payment_preimage, option),
712                         (3, resolving_tx, option),
713                 });
714                 Ok(Self {
715                         commitment_tx_output_idx: if mapped_commitment_tx_output_idx == u32::max_value() { None } else { Some(mapped_commitment_tx_output_idx) },
716                         resolving_txid,
717                         payment_preimage,
718                         resolving_tx,
719                 })
720         }
721 }
722
723 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
724 /// on-chain transactions to ensure no loss of funds occurs.
725 ///
726 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
727 /// information and are actively monitoring the chain.
728 ///
729 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
730 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
731 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
732 /// returned block hash and the the current chain and then reconnecting blocks to get to the
733 /// best chain) upon deserializing the object!
734 pub struct ChannelMonitor<Signer: WriteableEcdsaChannelSigner> {
735         #[cfg(test)]
736         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
737         #[cfg(not(test))]
738         pub(super) inner: Mutex<ChannelMonitorImpl<Signer>>,
739 }
740
741 impl<Signer: WriteableEcdsaChannelSigner> Clone for ChannelMonitor<Signer> where Signer: Clone {
742         fn clone(&self) -> Self {
743                 let inner = self.inner.lock().unwrap().clone();
744                 ChannelMonitor::from_impl(inner)
745         }
746 }
747
748 #[derive(Clone, PartialEq)]
749 pub(crate) struct ChannelMonitorImpl<Signer: WriteableEcdsaChannelSigner> {
750         latest_update_id: u64,
751         commitment_transaction_number_obscure_factor: u64,
752
753         destination_script: Script,
754         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
755         counterparty_payment_script: Script,
756         shutdown_script: Option<Script>,
757
758         channel_keys_id: [u8; 32],
759         holder_revocation_basepoint: PublicKey,
760         funding_info: (OutPoint, Script),
761         current_counterparty_commitment_txid: Option<Txid>,
762         prev_counterparty_commitment_txid: Option<Txid>,
763
764         counterparty_commitment_params: CounterpartyCommitmentParameters,
765         funding_redeemscript: Script,
766         channel_value_satoshis: u64,
767         // first is the idx of the first of the two per-commitment points
768         their_cur_per_commitment_points: Option<(u64, PublicKey, Option<PublicKey>)>,
769
770         on_holder_tx_csv: u16,
771
772         commitment_secrets: CounterpartyCommitmentSecrets,
773         /// The set of outpoints in each counterparty commitment transaction. We always need at least
774         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
775         /// transaction broadcast as we need to be able to construct the witness script in all cases.
776         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
777         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
778         /// Nor can we figure out their commitment numbers without the commitment transaction they are
779         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
780         /// commitment transactions which we find on-chain, mapping them to the commitment number which
781         /// can be used to derive the revocation key and claim the transactions.
782         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
783         /// Cache used to make pruning of payment_preimages faster.
784         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
785         /// counterparty transactions (ie should remain pretty small).
786         /// Serialized to disk but should generally not be sent to Watchtowers.
787         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
788
789         counterparty_fulfilled_htlcs: HashMap<SentHTLCId, PaymentPreimage>,
790
791         // We store two holder commitment transactions to avoid any race conditions where we may update
792         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
793         // various monitors for one channel being out of sync, and us broadcasting a holder
794         // transaction for which we have deleted claim information on some watchtowers.
795         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
796         current_holder_commitment_tx: HolderSignedTx,
797
798         // Used just for ChannelManager to make sure it has the latest channel data during
799         // deserialization
800         current_counterparty_commitment_number: u64,
801         // Used just for ChannelManager to make sure it has the latest channel data during
802         // deserialization
803         current_holder_commitment_number: u64,
804
805         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
806         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
807         /// remote commitment transactions are automatically removed when commitment transactions are
808         /// revoked.
809         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
810
811         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
812         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
813         // presumably user implementations thereof as well) where we update the in-memory channel
814         // object, then before the persistence finishes (as it's all under a read-lock), we return
815         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
816         // the pre-event state here, but have processed the event in the `ChannelManager`.
817         // Note that because the `event_lock` in `ChainMonitor` is only taken in
818         // block/transaction-connected events and *not* during block/transaction-disconnected events,
819         // we further MUST NOT generate events during block/transaction-disconnection.
820         pending_monitor_events: Vec<MonitorEvent>,
821
822         pub(super) pending_events: Vec<Event>,
823         pub(super) is_processing_pending_events: bool,
824
825         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
826         // which to take actions once they reach enough confirmations. Each entry includes the
827         // transaction's id and the height when the transaction was confirmed on chain.
828         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
829
830         // If we get serialized out and re-read, we need to make sure that the chain monitoring
831         // interface knows about the TXOs that we want to be notified of spends of. We could probably
832         // be smart and derive them from the above storage fields, but its much simpler and more
833         // Obviously Correct (tm) if we just keep track of them explicitly.
834         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
835
836         #[cfg(test)]
837         pub onchain_tx_handler: OnchainTxHandler<Signer>,
838         #[cfg(not(test))]
839         onchain_tx_handler: OnchainTxHandler<Signer>,
840
841         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
842         // channel has been force-closed. After this is set, no further holder commitment transaction
843         // updates may occur, and we panic!() if one is provided.
844         lockdown_from_offchain: bool,
845
846         // Set once we've signed a holder commitment transaction and handed it over to our
847         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
848         // may occur, and we fail any such monitor updates.
849         //
850         // In case of update rejection due to a locally already signed commitment transaction, we
851         // nevertheless store update content to track in case of concurrent broadcast by another
852         // remote monitor out-of-order with regards to the block view.
853         holder_tx_signed: bool,
854
855         // If a spend of the funding output is seen, we set this to true and reject any further
856         // updates. This prevents any further changes in the offchain state no matter the order
857         // of block connection between ChannelMonitors and the ChannelManager.
858         funding_spend_seen: bool,
859
860         /// Set to `Some` of the confirmed transaction spending the funding input of the channel after
861         /// reaching `ANTI_REORG_DELAY` confirmations.
862         funding_spend_confirmed: Option<Txid>,
863
864         confirmed_commitment_tx_counterparty_output: CommitmentTxCounterpartyOutputInfo,
865         /// The set of HTLCs which have been either claimed or failed on chain and have reached
866         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
867         /// spending CSV for revocable outputs).
868         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
869
870         /// The set of `SpendableOutput` events which we have already passed upstream to be claimed.
871         /// These are tracked explicitly to ensure that we don't generate the same events redundantly
872         /// if users duplicatively confirm old transactions. Specifically for transactions claiming a
873         /// revoked remote outpoint we otherwise have no tracking at all once they've reached
874         /// [`ANTI_REORG_DELAY`], so we have to track them here.
875         spendable_txids_confirmed: Vec<Txid>,
876
877         // We simply modify best_block in Channel's block_connected so that serialization is
878         // consistent but hopefully the users' copy handles block_connected in a consistent way.
879         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
880         // their best_block from its state and not based on updated copies that didn't run through
881         // the full block_connected).
882         best_block: BestBlock,
883
884         /// The node_id of our counterparty
885         counterparty_node_id: Option<PublicKey>,
886
887         /// Initial counterparty commmitment data needed to recreate the commitment tx
888         /// in the persistence pipeline for third-party watchtowers. This will only be present on
889         /// monitors created after 0.0.117.
890         ///
891         /// Ordering of tuple data: (their_per_commitment_point, feerate_per_kw, to_broadcaster_sats,
892         /// to_countersignatory_sats)
893         initial_counterparty_commitment_info: Option<(PublicKey, u32, u64, u64)>,
894 }
895
896 /// Transaction outputs to watch for on-chain spends.
897 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
898
899 impl<Signer: WriteableEcdsaChannelSigner> PartialEq for ChannelMonitor<Signer> where Signer: PartialEq {
900         fn eq(&self, other: &Self) -> bool {
901                 // We need some kind of total lockorder. Absent a better idea, we sort by position in
902                 // memory and take locks in that order (assuming that we can't move within memory while a
903                 // lock is held).
904                 let ord = ((self as *const _) as usize) < ((other as *const _) as usize);
905                 let a = if ord { self.inner.unsafe_well_ordered_double_lock_self() } else { other.inner.unsafe_well_ordered_double_lock_self() };
906                 let b = if ord { other.inner.unsafe_well_ordered_double_lock_self() } else { self.inner.unsafe_well_ordered_double_lock_self() };
907                 a.eq(&b)
908         }
909 }
910
911 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitor<Signer> {
912         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
913                 self.inner.lock().unwrap().write(writer)
914         }
915 }
916
917 // These are also used for ChannelMonitorUpdate, above.
918 const SERIALIZATION_VERSION: u8 = 1;
919 const MIN_SERIALIZATION_VERSION: u8 = 1;
920
921 impl<Signer: WriteableEcdsaChannelSigner> Writeable for ChannelMonitorImpl<Signer> {
922         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
923                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
924
925                 self.latest_update_id.write(writer)?;
926
927                 // Set in initial Channel-object creation, so should always be set by now:
928                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
929
930                 self.destination_script.write(writer)?;
931                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
932                         writer.write_all(&[0; 1])?;
933                         broadcasted_holder_revokable_script.0.write(writer)?;
934                         broadcasted_holder_revokable_script.1.write(writer)?;
935                         broadcasted_holder_revokable_script.2.write(writer)?;
936                 } else {
937                         writer.write_all(&[1; 1])?;
938                 }
939
940                 self.counterparty_payment_script.write(writer)?;
941                 match &self.shutdown_script {
942                         Some(script) => script.write(writer)?,
943                         None => Script::new().write(writer)?,
944                 }
945
946                 self.channel_keys_id.write(writer)?;
947                 self.holder_revocation_basepoint.write(writer)?;
948                 writer.write_all(&self.funding_info.0.txid[..])?;
949                 writer.write_all(&self.funding_info.0.index.to_be_bytes())?;
950                 self.funding_info.1.write(writer)?;
951                 self.current_counterparty_commitment_txid.write(writer)?;
952                 self.prev_counterparty_commitment_txid.write(writer)?;
953
954                 self.counterparty_commitment_params.write(writer)?;
955                 self.funding_redeemscript.write(writer)?;
956                 self.channel_value_satoshis.write(writer)?;
957
958                 match self.their_cur_per_commitment_points {
959                         Some((idx, pubkey, second_option)) => {
960                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
961                                 writer.write_all(&pubkey.serialize())?;
962                                 match second_option {
963                                         Some(second_pubkey) => {
964                                                 writer.write_all(&second_pubkey.serialize())?;
965                                         },
966                                         None => {
967                                                 writer.write_all(&[0; 33])?;
968                                         },
969                                 }
970                         },
971                         None => {
972                                 writer.write_all(&byte_utils::be48_to_array(0))?;
973                         },
974                 }
975
976                 writer.write_all(&self.on_holder_tx_csv.to_be_bytes())?;
977
978                 self.commitment_secrets.write(writer)?;
979
980                 macro_rules! serialize_htlc_in_commitment {
981                         ($htlc_output: expr) => {
982                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
983                                 writer.write_all(&$htlc_output.amount_msat.to_be_bytes())?;
984                                 writer.write_all(&$htlc_output.cltv_expiry.to_be_bytes())?;
985                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
986                                 $htlc_output.transaction_output_index.write(writer)?;
987                         }
988                 }
989
990                 writer.write_all(&(self.counterparty_claimable_outpoints.len() as u64).to_be_bytes())?;
991                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
992                         writer.write_all(&txid[..])?;
993                         writer.write_all(&(htlc_infos.len() as u64).to_be_bytes())?;
994                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
995                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
996                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
997                                         "HTLC Sources for all revoked commitment transactions should be none!");
998                                 serialize_htlc_in_commitment!(htlc_output);
999                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
1000                         }
1001                 }
1002
1003                 writer.write_all(&(self.counterparty_commitment_txn_on_chain.len() as u64).to_be_bytes())?;
1004                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
1005                         writer.write_all(&txid[..])?;
1006                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1007                 }
1008
1009                 writer.write_all(&(self.counterparty_hash_commitment_number.len() as u64).to_be_bytes())?;
1010                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
1011                         writer.write_all(&payment_hash.0[..])?;
1012                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
1013                 }
1014
1015                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
1016                         writer.write_all(&[1; 1])?;
1017                         prev_holder_tx.write(writer)?;
1018                 } else {
1019                         writer.write_all(&[0; 1])?;
1020                 }
1021
1022                 self.current_holder_commitment_tx.write(writer)?;
1023
1024                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
1025                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
1026
1027                 writer.write_all(&(self.payment_preimages.len() as u64).to_be_bytes())?;
1028                 for payment_preimage in self.payment_preimages.values() {
1029                         writer.write_all(&payment_preimage.0[..])?;
1030                 }
1031
1032                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
1033                         MonitorEvent::HTLCEvent(_) => true,
1034                         MonitorEvent::HolderForceClosed(_) => true,
1035                         _ => false,
1036                 }).count() as u64).to_be_bytes())?;
1037                 for event in self.pending_monitor_events.iter() {
1038                         match event {
1039                                 MonitorEvent::HTLCEvent(upd) => {
1040                                         0u8.write(writer)?;
1041                                         upd.write(writer)?;
1042                                 },
1043                                 MonitorEvent::HolderForceClosed(_) => 1u8.write(writer)?,
1044                                 _ => {}, // Covered in the TLV writes below
1045                         }
1046                 }
1047
1048                 writer.write_all(&(self.pending_events.len() as u64).to_be_bytes())?;
1049                 for event in self.pending_events.iter() {
1050                         event.write(writer)?;
1051                 }
1052
1053                 self.best_block.block_hash().write(writer)?;
1054                 writer.write_all(&self.best_block.height().to_be_bytes())?;
1055
1056                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
1057                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
1058                         entry.write(writer)?;
1059                 }
1060
1061                 (self.outputs_to_watch.len() as u64).write(writer)?;
1062                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
1063                         txid.write(writer)?;
1064                         (idx_scripts.len() as u64).write(writer)?;
1065                         for (idx, script) in idx_scripts.iter() {
1066                                 idx.write(writer)?;
1067                                 script.write(writer)?;
1068                         }
1069                 }
1070                 self.onchain_tx_handler.write(writer)?;
1071
1072                 self.lockdown_from_offchain.write(writer)?;
1073                 self.holder_tx_signed.write(writer)?;
1074
1075                 write_tlv_fields!(writer, {
1076                         (1, self.funding_spend_confirmed, option),
1077                         (3, self.htlcs_resolved_on_chain, required_vec),
1078                         (5, self.pending_monitor_events, required_vec),
1079                         (7, self.funding_spend_seen, required),
1080                         (9, self.counterparty_node_id, option),
1081                         (11, self.confirmed_commitment_tx_counterparty_output, option),
1082                         (13, self.spendable_txids_confirmed, required_vec),
1083                         (15, self.counterparty_fulfilled_htlcs, required),
1084                         (17, self.initial_counterparty_commitment_info, option),
1085                 });
1086
1087                 Ok(())
1088         }
1089 }
1090
1091 macro_rules! _process_events_body {
1092         ($self_opt: expr, $event_to_handle: expr, $handle_event: expr) => {
1093                 loop {
1094                         let (pending_events, repeated_events);
1095                         if let Some(us) = $self_opt {
1096                                 let mut inner = us.inner.lock().unwrap();
1097                                 if inner.is_processing_pending_events {
1098                                         break;
1099                                 }
1100                                 inner.is_processing_pending_events = true;
1101
1102                                 pending_events = inner.pending_events.clone();
1103                                 repeated_events = inner.get_repeated_events();
1104                         } else { break; }
1105                         let num_events = pending_events.len();
1106
1107                         for event in pending_events.into_iter().chain(repeated_events.into_iter()) {
1108                                 $event_to_handle = event;
1109                                 $handle_event;
1110                         }
1111
1112                         if let Some(us) = $self_opt {
1113                                 let mut inner = us.inner.lock().unwrap();
1114                                 inner.pending_events.drain(..num_events);
1115                                 inner.is_processing_pending_events = false;
1116                                 if !inner.pending_events.is_empty() {
1117                                         // If there's more events to process, go ahead and do so.
1118                                         continue;
1119                                 }
1120                         }
1121                         break;
1122                 }
1123         }
1124 }
1125 pub(super) use _process_events_body as process_events_body;
1126
1127 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1128         /// For lockorder enforcement purposes, we need to have a single site which constructs the
1129         /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
1130         /// PartialEq implementation) we may decide a lockorder violation has occurred.
1131         fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
1132                 ChannelMonitor { inner: Mutex::new(imp) }
1133         }
1134
1135         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
1136                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
1137                           channel_parameters: &ChannelTransactionParameters,
1138                           funding_redeemscript: Script, channel_value_satoshis: u64,
1139                           commitment_transaction_number_obscure_factor: u64,
1140                           initial_holder_commitment_tx: HolderCommitmentTransaction,
1141                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
1142
1143                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
1144                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
1145                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
1146
1147                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
1148                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
1149                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
1150                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
1151
1152                 let channel_keys_id = keys.channel_keys_id();
1153                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
1154
1155                 // block for Rust 1.34 compat
1156                 let (holder_commitment_tx, current_holder_commitment_number) = {
1157                         let trusted_tx = initial_holder_commitment_tx.trust();
1158                         let txid = trusted_tx.txid();
1159
1160                         let tx_keys = trusted_tx.keys();
1161                         let holder_commitment_tx = HolderSignedTx {
1162                                 txid,
1163                                 revocation_key: tx_keys.revocation_key,
1164                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1165                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1166                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1167                                 per_commitment_point: tx_keys.per_commitment_point,
1168                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1169                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1170                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1171                         };
1172                         (holder_commitment_tx, trusted_tx.commitment_number())
1173                 };
1174
1175                 let onchain_tx_handler =
1176                         OnchainTxHandler::new(destination_script.clone(), keys,
1177                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx);
1178
1179                 let mut outputs_to_watch = HashMap::new();
1180                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1181
1182                 Self::from_impl(ChannelMonitorImpl {
1183                         latest_update_id: 0,
1184                         commitment_transaction_number_obscure_factor,
1185
1186                         destination_script: destination_script.clone(),
1187                         broadcasted_holder_revokable_script: None,
1188                         counterparty_payment_script,
1189                         shutdown_script,
1190
1191                         channel_keys_id,
1192                         holder_revocation_basepoint,
1193                         funding_info,
1194                         current_counterparty_commitment_txid: None,
1195                         prev_counterparty_commitment_txid: None,
1196
1197                         counterparty_commitment_params,
1198                         funding_redeemscript,
1199                         channel_value_satoshis,
1200                         their_cur_per_commitment_points: None,
1201
1202                         on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1203
1204                         commitment_secrets: CounterpartyCommitmentSecrets::new(),
1205                         counterparty_claimable_outpoints: HashMap::new(),
1206                         counterparty_commitment_txn_on_chain: HashMap::new(),
1207                         counterparty_hash_commitment_number: HashMap::new(),
1208                         counterparty_fulfilled_htlcs: HashMap::new(),
1209
1210                         prev_holder_signed_commitment_tx: None,
1211                         current_holder_commitment_tx: holder_commitment_tx,
1212                         current_counterparty_commitment_number: 1 << 48,
1213                         current_holder_commitment_number,
1214
1215                         payment_preimages: HashMap::new(),
1216                         pending_monitor_events: Vec::new(),
1217                         pending_events: Vec::new(),
1218                         is_processing_pending_events: false,
1219
1220                         onchain_events_awaiting_threshold_conf: Vec::new(),
1221                         outputs_to_watch,
1222
1223                         onchain_tx_handler,
1224
1225                         lockdown_from_offchain: false,
1226                         holder_tx_signed: false,
1227                         funding_spend_seen: false,
1228                         funding_spend_confirmed: None,
1229                         confirmed_commitment_tx_counterparty_output: None,
1230                         htlcs_resolved_on_chain: Vec::new(),
1231                         spendable_txids_confirmed: Vec::new(),
1232
1233                         best_block,
1234                         counterparty_node_id: Some(counterparty_node_id),
1235                         initial_counterparty_commitment_info: None,
1236                 })
1237         }
1238
1239         #[cfg(test)]
1240         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1241                 self.inner.lock().unwrap().provide_secret(idx, secret)
1242         }
1243
1244         /// A variant of `Self::provide_latest_counterparty_commitment_tx` used to provide
1245         /// additional information to the monitor to store in order to recreate the initial
1246         /// counterparty commitment transaction during persistence (mainly for use in third-party
1247         /// watchtowers).
1248         ///
1249         /// This is used to provide the counterparty commitment information directly to the monitor
1250         /// before the initial persistence of a new channel.
1251         pub(crate) fn provide_initial_counterparty_commitment_tx<L: Deref>(
1252                 &self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1253                 commitment_number: u64, their_cur_per_commitment_point: PublicKey, feerate_per_kw: u32,
1254                 to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, logger: &L,
1255         )
1256         where L::Target: Logger
1257         {
1258                 self.inner.lock().unwrap().provide_initial_counterparty_commitment_tx(txid,
1259                         htlc_outputs, commitment_number, their_cur_per_commitment_point, feerate_per_kw,
1260                         to_broadcaster_value_sat, to_countersignatory_value_sat, logger);
1261         }
1262
1263         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1264         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1265         /// possibly future revocation/preimage information) to claim outputs where possible.
1266         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1267         #[cfg(test)]
1268         fn provide_latest_counterparty_commitment_tx<L: Deref>(
1269                 &self,
1270                 txid: Txid,
1271                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1272                 commitment_number: u64,
1273                 their_per_commitment_point: PublicKey,
1274                 logger: &L,
1275         ) where L::Target: Logger {
1276                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1277                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1278         }
1279
1280         #[cfg(test)]
1281         fn provide_latest_holder_commitment_tx(
1282                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1283                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1284         ) -> Result<(), ()> {
1285                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs, &Vec::new(), Vec::new()).map_err(|_| ())
1286         }
1287
1288         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1289         /// off-chain state with a new commitment transaction.
1290         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1291                 &self,
1292                 payment_hash: &PaymentHash,
1293                 payment_preimage: &PaymentPreimage,
1294                 broadcaster: &B,
1295                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1296                 logger: &L,
1297         ) where
1298                 B::Target: BroadcasterInterface,
1299                 F::Target: FeeEstimator,
1300                 L::Target: Logger,
1301         {
1302                 self.inner.lock().unwrap().provide_payment_preimage(
1303                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1304         }
1305
1306         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1307         /// itself.
1308         ///
1309         /// panics if the given update is not the next update by update_id.
1310         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1311                 &self,
1312                 updates: &ChannelMonitorUpdate,
1313                 broadcaster: &B,
1314                 fee_estimator: F,
1315                 logger: &L,
1316         ) -> Result<(), ()>
1317         where
1318                 B::Target: BroadcasterInterface,
1319                 F::Target: FeeEstimator,
1320                 L::Target: Logger,
1321         {
1322                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1323         }
1324
1325         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1326         /// ChannelMonitor.
1327         pub fn get_latest_update_id(&self) -> u64 {
1328                 self.inner.lock().unwrap().get_latest_update_id()
1329         }
1330
1331         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1332         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1333                 self.inner.lock().unwrap().get_funding_txo().clone()
1334         }
1335
1336         /// Gets a list of txids, with their output scripts (in the order they appear in the
1337         /// transaction), which we must learn about spends of via block_connected().
1338         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1339                 self.inner.lock().unwrap().get_outputs_to_watch()
1340                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1341         }
1342
1343         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1344         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1345         /// have been registered.
1346         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1347                 let lock = self.inner.lock().unwrap();
1348                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1349                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1350                         for (index, script_pubkey) in outputs.iter() {
1351                                 assert!(*index <= u16::max_value() as u32);
1352                                 filter.register_output(WatchedOutput {
1353                                         block_hash: None,
1354                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1355                                         script_pubkey: script_pubkey.clone(),
1356                                 });
1357                         }
1358                 }
1359         }
1360
1361         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1362         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1363         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1364                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1365         }
1366
1367         /// Processes [`SpendableOutputs`] events produced from each [`ChannelMonitor`] upon maturity.
1368         ///
1369         /// For channels featuring anchor outputs, this method will also process [`BumpTransaction`]
1370         /// events produced from each [`ChannelMonitor`] while there is a balance to claim onchain
1371         /// within each channel. As the confirmation of a commitment transaction may be critical to the
1372         /// safety of funds, we recommend invoking this every 30 seconds, or lower if running in an
1373         /// environment with spotty connections, like on mobile.
1374         ///
1375         /// An [`EventHandler`] may safely call back to the provider, though this shouldn't be needed in
1376         /// order to handle these events.
1377         ///
1378         /// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
1379         /// [`BumpTransaction`]: crate::events::Event::BumpTransaction
1380         pub fn process_pending_events<H: Deref>(&self, handler: &H) where H::Target: EventHandler {
1381                 let mut ev;
1382                 process_events_body!(Some(self), ev, handler.handle_event(ev));
1383         }
1384
1385         /// Processes any events asynchronously.
1386         ///
1387         /// See [`Self::process_pending_events`] for more information.
1388         pub async fn process_pending_events_async<Future: core::future::Future, H: Fn(Event) -> Future>(
1389                 &self, handler: &H
1390         ) {
1391                 let mut ev;
1392                 process_events_body!(Some(self), ev, { handler(ev).await });
1393         }
1394
1395         #[cfg(test)]
1396         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1397                 let mut ret = Vec::new();
1398                 let mut lck = self.inner.lock().unwrap();
1399                 mem::swap(&mut ret, &mut lck.pending_events);
1400                 ret.append(&mut lck.get_repeated_events());
1401                 ret
1402         }
1403
1404         /// Gets the counterparty's initial commitment transaction. The returned commitment
1405         /// transaction is unsigned. This is intended to be called during the initial persistence of
1406         /// the monitor (inside an implementation of [`Persist::persist_new_channel`]), to allow for
1407         /// watchtowers in the persistence pipeline to have enough data to form justice transactions.
1408         ///
1409         /// This is similar to [`Self::counterparty_commitment_txs_from_update`], except
1410         /// that for the initial commitment transaction, we don't have a corresponding update.
1411         ///
1412         /// This will only return `Some` for channel monitors that have been created after upgrading
1413         /// to LDK 0.0.117+.
1414         ///
1415         /// [`Persist::persist_new_channel`]: crate::chain::chainmonitor::Persist::persist_new_channel
1416         pub fn initial_counterparty_commitment_tx(&self) -> Option<CommitmentTransaction> {
1417                 self.inner.lock().unwrap().initial_counterparty_commitment_tx()
1418         }
1419
1420         /// Gets all of the counterparty commitment transactions provided by the given update. This
1421         /// may be empty if the update doesn't include any new counterparty commitments. Returned
1422         /// commitment transactions are unsigned.
1423         ///
1424         /// This is provided so that watchtower clients in the persistence pipeline are able to build
1425         /// justice transactions for each counterparty commitment upon each update. It's intended to be
1426         /// used within an implementation of [`Persist::update_persisted_channel`], which is provided
1427         /// with a monitor and an update. Once revoked, signing a justice transaction can be done using
1428         /// [`Self::sign_to_local_justice_tx`].
1429         ///
1430         /// It is expected that a watchtower client may use this method to retrieve the latest counterparty
1431         /// commitment transaction(s), and then hold the necessary data until a later update in which
1432         /// the monitor has been updated with the corresponding revocation data, at which point the
1433         /// monitor can sign the justice transaction.
1434         ///
1435         /// This will only return a non-empty list for monitor updates that have been created after
1436         /// upgrading to LDK 0.0.117+. Note that no restriction lies on the monitors themselves, which
1437         /// may have been created prior to upgrading.
1438         ///
1439         /// [`Persist::update_persisted_channel`]: crate::chain::chainmonitor::Persist::update_persisted_channel
1440         pub fn counterparty_commitment_txs_from_update(&self, update: &ChannelMonitorUpdate) -> Vec<CommitmentTransaction> {
1441                 self.inner.lock().unwrap().counterparty_commitment_txs_from_update(update)
1442         }
1443
1444         /// Wrapper around [`EcdsaChannelSigner::sign_justice_revoked_output`] to make
1445         /// signing the justice transaction easier for implementors of
1446         /// [`chain::chainmonitor::Persist`]. On success this method returns the provided transaction
1447         /// signing the input at `input_idx`. This method will only produce a valid signature for
1448         /// a transaction spending the `to_local` output of a commitment transaction, i.e. this cannot
1449         /// be used for revoked HTLC outputs.
1450         ///
1451         /// `Value` is the value of the output being spent by the input at `input_idx`, committed
1452         /// in the BIP 143 signature.
1453         ///
1454         /// This method will only succeed if this monitor has received the revocation secret for the
1455         /// provided `commitment_number`. If a commitment number is provided that does not correspond
1456         /// to the commitment transaction being revoked, this will return a signed transaction, but
1457         /// the signature will not be valid.
1458         ///
1459         /// [`EcdsaChannelSigner::sign_justice_revoked_output`]: crate::sign::EcdsaChannelSigner::sign_justice_revoked_output
1460         /// [`Persist`]: crate::chain::chainmonitor::Persist
1461         pub fn sign_to_local_justice_tx(&self, justice_tx: Transaction, input_idx: usize, value: u64, commitment_number: u64) -> Result<Transaction, ()> {
1462                 self.inner.lock().unwrap().sign_to_local_justice_tx(justice_tx, input_idx, value, commitment_number)
1463         }
1464
1465         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1466                 self.inner.lock().unwrap().get_min_seen_secret()
1467         }
1468
1469         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1470                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1471         }
1472
1473         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1474                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1475         }
1476
1477         /// Gets the `node_id` of the counterparty for this channel.
1478         ///
1479         /// Will be `None` for channels constructed on LDK versions prior to 0.0.110 and always `Some`
1480         /// otherwise.
1481         pub fn get_counterparty_node_id(&self) -> Option<PublicKey> {
1482                 self.inner.lock().unwrap().counterparty_node_id
1483         }
1484
1485         /// Used by [`ChannelManager`] deserialization to broadcast the latest holder state if its copy
1486         /// of the channel state was out-of-date.
1487         ///
1488         /// You may also use this to broadcast the latest local commitment transaction, either because
1489         /// a monitor update failed or because we've fallen behind (i.e. we've received proof that our
1490         /// counterparty side knows a revocation secret we gave them that they shouldn't know).
1491         ///
1492         /// Broadcasting these transactions in the second case is UNSAFE, as they allow counterparty
1493         /// side to punish you. Nevertheless you may want to broadcast them if counterparty doesn't
1494         /// close channel with their commitment transaction after a substantial amount of time. Best
1495         /// may be to contact the other node operator out-of-band to coordinate other options available
1496         /// to you.
1497         ///
1498         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
1499         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1500         where L::Target: Logger {
1501                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1502         }
1503
1504         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1505         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1506         /// revoked commitment transaction.
1507         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1508         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1509         where L::Target: Logger {
1510                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1511         }
1512
1513         /// Processes transactions in a newly connected block, which may result in any of the following:
1514         /// - update the monitor's state against resolved HTLCs
1515         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1516         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1517         /// - detect settled outputs for later spending
1518         /// - schedule and bump any in-flight claims
1519         ///
1520         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1521         /// [`get_outputs_to_watch`].
1522         ///
1523         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1524         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1525                 &self,
1526                 header: &BlockHeader,
1527                 txdata: &TransactionData,
1528                 height: u32,
1529                 broadcaster: B,
1530                 fee_estimator: F,
1531                 logger: L,
1532         ) -> Vec<TransactionOutputs>
1533         where
1534                 B::Target: BroadcasterInterface,
1535                 F::Target: FeeEstimator,
1536                 L::Target: Logger,
1537         {
1538                 self.inner.lock().unwrap().block_connected(
1539                         header, txdata, height, broadcaster, fee_estimator, logger)
1540         }
1541
1542         /// Determines if the disconnected block contained any transactions of interest and updates
1543         /// appropriately.
1544         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1545                 &self,
1546                 header: &BlockHeader,
1547                 height: u32,
1548                 broadcaster: B,
1549                 fee_estimator: F,
1550                 logger: L,
1551         ) where
1552                 B::Target: BroadcasterInterface,
1553                 F::Target: FeeEstimator,
1554                 L::Target: Logger,
1555         {
1556                 self.inner.lock().unwrap().block_disconnected(
1557                         header, height, broadcaster, fee_estimator, logger)
1558         }
1559
1560         /// Processes transactions confirmed in a block with the given header and height, returning new
1561         /// outputs to watch. See [`block_connected`] for details.
1562         ///
1563         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1564         /// blocks. See [`chain::Confirm`] for calling expectations.
1565         ///
1566         /// [`block_connected`]: Self::block_connected
1567         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1568                 &self,
1569                 header: &BlockHeader,
1570                 txdata: &TransactionData,
1571                 height: u32,
1572                 broadcaster: B,
1573                 fee_estimator: F,
1574                 logger: L,
1575         ) -> Vec<TransactionOutputs>
1576         where
1577                 B::Target: BroadcasterInterface,
1578                 F::Target: FeeEstimator,
1579                 L::Target: Logger,
1580         {
1581                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1582                 self.inner.lock().unwrap().transactions_confirmed(
1583                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1584         }
1585
1586         /// Processes a transaction that was reorganized out of the chain.
1587         ///
1588         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1589         /// than blocks. See [`chain::Confirm`] for calling expectations.
1590         ///
1591         /// [`block_disconnected`]: Self::block_disconnected
1592         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1593                 &self,
1594                 txid: &Txid,
1595                 broadcaster: B,
1596                 fee_estimator: F,
1597                 logger: L,
1598         ) where
1599                 B::Target: BroadcasterInterface,
1600                 F::Target: FeeEstimator,
1601                 L::Target: Logger,
1602         {
1603                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1604                 self.inner.lock().unwrap().transaction_unconfirmed(
1605                         txid, broadcaster, &bounded_fee_estimator, logger);
1606         }
1607
1608         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1609         /// [`block_connected`] for details.
1610         ///
1611         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1612         /// blocks. See [`chain::Confirm`] for calling expectations.
1613         ///
1614         /// [`block_connected`]: Self::block_connected
1615         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1616                 &self,
1617                 header: &BlockHeader,
1618                 height: u32,
1619                 broadcaster: B,
1620                 fee_estimator: F,
1621                 logger: L,
1622         ) -> Vec<TransactionOutputs>
1623         where
1624                 B::Target: BroadcasterInterface,
1625                 F::Target: FeeEstimator,
1626                 L::Target: Logger,
1627         {
1628                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1629                 self.inner.lock().unwrap().best_block_updated(
1630                         header, height, broadcaster, &bounded_fee_estimator, logger)
1631         }
1632
1633         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1634         pub fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1635                 let inner = self.inner.lock().unwrap();
1636                 let mut txids: Vec<(Txid, Option<BlockHash>)> = inner.onchain_events_awaiting_threshold_conf
1637                         .iter()
1638                         .map(|entry| (entry.txid, entry.block_hash))
1639                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1640                         .collect();
1641                 txids.sort_unstable();
1642                 txids.dedup();
1643                 txids
1644         }
1645
1646         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1647         /// [`chain::Confirm`] interfaces.
1648         pub fn current_best_block(&self) -> BestBlock {
1649                 self.inner.lock().unwrap().best_block.clone()
1650         }
1651
1652         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
1653         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
1654         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
1655         /// invoking this every 30 seconds, or lower if running in an environment with spotty
1656         /// connections, like on mobile.
1657         pub fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
1658                 &self, broadcaster: B, fee_estimator: F, logger: L,
1659         )
1660         where
1661                 B::Target: BroadcasterInterface,
1662                 F::Target: FeeEstimator,
1663                 L::Target: Logger,
1664         {
1665                 let fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1666                 let mut inner = self.inner.lock().unwrap();
1667                 let current_height = inner.best_block.height;
1668                 inner.onchain_tx_handler.rebroadcast_pending_claims(
1669                         current_height, &broadcaster, &fee_estimator, &logger,
1670                 );
1671         }
1672
1673         /// Returns the descriptors for relevant outputs (i.e., those that we can spend) within the
1674         /// transaction if they exist and the transaction has at least [`ANTI_REORG_DELAY`]
1675         /// confirmations.
1676         ///
1677         /// Descriptors returned by this method are primarily exposed via [`Event::SpendableOutputs`]
1678         /// once they are no longer under reorg risk. This method serves as a way to retrieve these
1679         /// descriptors at a later time, either for historical purposes, or to replay any
1680         /// missed/unhandled descriptors. For the purpose of gathering historical records, if the
1681         /// channel close has fully resolved (i.e., [`ChannelMonitor::get_claimable_balances`] returns
1682         /// an empty set), you can retrieve all spendable outputs by providing all descendant spending
1683         /// transactions starting from the channel's funding or closing transaction that have at least
1684         /// [`ANTI_REORG_DELAY`] confirmations.
1685         ///
1686         /// `tx` is a transaction we'll scan the outputs of. Any transaction can be provided. If any
1687         /// outputs which can be spent by us are found, at least one descriptor is returned.
1688         ///
1689         /// `confirmation_height` must be the height of the block in which `tx` was included in.
1690         pub fn get_spendable_outputs(&self, tx: &Transaction, confirmation_height: u32) -> Vec<SpendableOutputDescriptor> {
1691                 let inner = self.inner.lock().unwrap();
1692                 let current_height = inner.best_block.height;
1693                 if current_height.saturating_sub(ANTI_REORG_DELAY) + 1 >= confirmation_height {
1694                         inner.get_spendable_outputs(tx)
1695                 } else {
1696                         Vec::new()
1697                 }
1698         }
1699 }
1700
1701 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
1702         /// Helper for get_claimable_balances which does the work for an individual HTLC, generating up
1703         /// to one `Balance` for the HTLC.
1704         fn get_htlc_balance(&self, htlc: &HTLCOutputInCommitment, holder_commitment: bool,
1705                 counterparty_revoked_commitment: bool, confirmed_txid: Option<Txid>)
1706         -> Option<Balance> {
1707                 let htlc_commitment_tx_output_idx =
1708                         if let Some(v) = htlc.transaction_output_index { v } else { return None; };
1709
1710                 let mut htlc_spend_txid_opt = None;
1711                 let mut htlc_spend_tx_opt = None;
1712                 let mut holder_timeout_spend_pending = None;
1713                 let mut htlc_spend_pending = None;
1714                 let mut holder_delayed_output_pending = None;
1715                 for event in self.onchain_events_awaiting_threshold_conf.iter() {
1716                         match event.event {
1717                                 OnchainEvent::HTLCUpdate { commitment_tx_output_idx, htlc_value_satoshis, .. }
1718                                 if commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) => {
1719                                         debug_assert!(htlc_spend_txid_opt.is_none());
1720                                         htlc_spend_txid_opt = Some(&event.txid);
1721                                         debug_assert!(htlc_spend_tx_opt.is_none());
1722                                         htlc_spend_tx_opt = event.transaction.as_ref();
1723                                         debug_assert!(holder_timeout_spend_pending.is_none());
1724                                         debug_assert_eq!(htlc_value_satoshis.unwrap(), htlc.amount_msat / 1000);
1725                                         holder_timeout_spend_pending = Some(event.confirmation_threshold());
1726                                 },
1727                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. }
1728                                 if commitment_tx_output_idx == htlc_commitment_tx_output_idx => {
1729                                         debug_assert!(htlc_spend_txid_opt.is_none());
1730                                         htlc_spend_txid_opt = Some(&event.txid);
1731                                         debug_assert!(htlc_spend_tx_opt.is_none());
1732                                         htlc_spend_tx_opt = event.transaction.as_ref();
1733                                         debug_assert!(htlc_spend_pending.is_none());
1734                                         htlc_spend_pending = Some((event.confirmation_threshold(), preimage.is_some()));
1735                                 },
1736                                 OnchainEvent::MaturingOutput {
1737                                         descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) }
1738                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx => {
1739                                         debug_assert!(holder_delayed_output_pending.is_none());
1740                                         holder_delayed_output_pending = Some(event.confirmation_threshold());
1741                                 },
1742                                 _ => {},
1743                         }
1744                 }
1745                 let htlc_resolved = self.htlcs_resolved_on_chain.iter()
1746                         .find(|v| if v.commitment_tx_output_idx == Some(htlc_commitment_tx_output_idx) {
1747                                 debug_assert!(htlc_spend_txid_opt.is_none());
1748                                 htlc_spend_txid_opt = v.resolving_txid.as_ref();
1749                                 debug_assert!(htlc_spend_tx_opt.is_none());
1750                                 htlc_spend_tx_opt = v.resolving_tx.as_ref();
1751                                 true
1752                         } else { false });
1753                 debug_assert!(holder_timeout_spend_pending.is_some() as u8 + htlc_spend_pending.is_some() as u8 + htlc_resolved.is_some() as u8 <= 1);
1754
1755                 let htlc_commitment_outpoint = BitcoinOutPoint::new(confirmed_txid.unwrap(), htlc_commitment_tx_output_idx);
1756                 let htlc_output_to_spend =
1757                         if let Some(txid) = htlc_spend_txid_opt {
1758                                 // Because HTLC transactions either only have 1 input and 1 output (pre-anchors) or
1759                                 // are signed with SIGHASH_SINGLE|ANYONECANPAY under BIP-0143 (post-anchors), we can
1760                                 // locate the correct output by ensuring its adjacent input spends the HTLC output
1761                                 // in the commitment.
1762                                 if let Some(ref tx) = htlc_spend_tx_opt {
1763                                         let htlc_input_idx_opt = tx.input.iter().enumerate()
1764                                                 .find(|(_, input)| input.previous_output == htlc_commitment_outpoint)
1765                                                 .map(|(idx, _)| idx as u32);
1766                                         debug_assert!(htlc_input_idx_opt.is_some());
1767                                         BitcoinOutPoint::new(*txid, htlc_input_idx_opt.unwrap_or(0))
1768                                 } else {
1769                                         debug_assert!(!self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx());
1770                                         BitcoinOutPoint::new(*txid, 0)
1771                                 }
1772                         } else {
1773                                 htlc_commitment_outpoint
1774                         };
1775                 let htlc_output_spend_pending = self.onchain_tx_handler.is_output_spend_pending(&htlc_output_to_spend);
1776
1777                 if let Some(conf_thresh) = holder_delayed_output_pending {
1778                         debug_assert!(holder_commitment);
1779                         return Some(Balance::ClaimableAwaitingConfirmations {
1780                                 amount_satoshis: htlc.amount_msat / 1000,
1781                                 confirmation_height: conf_thresh,
1782                         });
1783                 } else if htlc_resolved.is_some() && !htlc_output_spend_pending {
1784                         // Funding transaction spends should be fully confirmed by the time any
1785                         // HTLC transactions are resolved, unless we're talking about a holder
1786                         // commitment tx, whose resolution is delayed until the CSV timeout is
1787                         // reached, even though HTLCs may be resolved after only
1788                         // ANTI_REORG_DELAY confirmations.
1789                         debug_assert!(holder_commitment || self.funding_spend_confirmed.is_some());
1790                 } else if counterparty_revoked_commitment {
1791                         let htlc_output_claim_pending = self.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1792                                 if let OnchainEvent::MaturingOutput {
1793                                         descriptor: SpendableOutputDescriptor::StaticOutput { .. }
1794                                 } = &event.event {
1795                                         if event.transaction.as_ref().map(|tx| tx.input.iter().any(|inp| {
1796                                                 if let Some(htlc_spend_txid) = htlc_spend_txid_opt {
1797                                                         tx.txid() == *htlc_spend_txid || inp.previous_output.txid == *htlc_spend_txid
1798                                                 } else {
1799                                                         Some(inp.previous_output.txid) == confirmed_txid &&
1800                                                                 inp.previous_output.vout == htlc_commitment_tx_output_idx
1801                                                 }
1802                                         })).unwrap_or(false) {
1803                                                 Some(())
1804                                         } else { None }
1805                                 } else { None }
1806                         });
1807                         if htlc_output_claim_pending.is_some() {
1808                                 // We already push `Balance`s onto the `res` list for every
1809                                 // `StaticOutput` in a `MaturingOutput` in the revoked
1810                                 // counterparty commitment transaction case generally, so don't
1811                                 // need to do so again here.
1812                         } else {
1813                                 debug_assert!(holder_timeout_spend_pending.is_none(),
1814                                         "HTLCUpdate OnchainEvents should never appear for preimage claims");
1815                                 debug_assert!(!htlc.offered || htlc_spend_pending.is_none() || !htlc_spend_pending.unwrap().1,
1816                                         "We don't (currently) generate preimage claims against revoked outputs, where did you get one?!");
1817                                 return Some(Balance::CounterpartyRevokedOutputClaimable {
1818                                         amount_satoshis: htlc.amount_msat / 1000,
1819                                 });
1820                         }
1821                 } else if htlc.offered == holder_commitment {
1822                         // If the payment was outbound, check if there's an HTLCUpdate
1823                         // indicating we have spent this HTLC with a timeout, claiming it back
1824                         // and awaiting confirmations on it.
1825                         if let Some(conf_thresh) = holder_timeout_spend_pending {
1826                                 return Some(Balance::ClaimableAwaitingConfirmations {
1827                                         amount_satoshis: htlc.amount_msat / 1000,
1828                                         confirmation_height: conf_thresh,
1829                                 });
1830                         } else {
1831                                 return Some(Balance::MaybeTimeoutClaimableHTLC {
1832                                         amount_satoshis: htlc.amount_msat / 1000,
1833                                         claimable_height: htlc.cltv_expiry,
1834                                         payment_hash: htlc.payment_hash,
1835                                 });
1836                         }
1837                 } else if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1838                         // Otherwise (the payment was inbound), only expose it as claimable if
1839                         // we know the preimage.
1840                         // Note that if there is a pending claim, but it did not use the
1841                         // preimage, we lost funds to our counterparty! We will then continue
1842                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1843                         debug_assert!(holder_timeout_spend_pending.is_none());
1844                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1845                                 return Some(Balance::ClaimableAwaitingConfirmations {
1846                                         amount_satoshis: htlc.amount_msat / 1000,
1847                                         confirmation_height: conf_thresh,
1848                                 });
1849                         } else {
1850                                 return Some(Balance::ContentiousClaimable {
1851                                         amount_satoshis: htlc.amount_msat / 1000,
1852                                         timeout_height: htlc.cltv_expiry,
1853                                         payment_hash: htlc.payment_hash,
1854                                         payment_preimage: *payment_preimage,
1855                                 });
1856                         }
1857                 } else if htlc_resolved.is_none() {
1858                         return Some(Balance::MaybePreimageClaimableHTLC {
1859                                 amount_satoshis: htlc.amount_msat / 1000,
1860                                 expiry_height: htlc.cltv_expiry,
1861                                 payment_hash: htlc.payment_hash,
1862                         });
1863                 }
1864                 None
1865         }
1866 }
1867
1868 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitor<Signer> {
1869         /// Gets the balances in this channel which are either claimable by us if we were to
1870         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1871         /// confirmation).
1872         ///
1873         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1874         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1875         /// balance, or until our counterparty has claimed the balance and accrued several
1876         /// confirmations on the claim transaction.
1877         ///
1878         /// Note that for `ChannelMonitors` which track a channel which went on-chain with versions of
1879         /// LDK prior to 0.0.111, balances may not be fully captured if our counterparty broadcasted
1880         /// a revoked state.
1881         ///
1882         /// See [`Balance`] for additional details on the types of claimable balances which
1883         /// may be returned here and their meanings.
1884         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1885                 let mut res = Vec::new();
1886                 let us = self.inner.lock().unwrap();
1887
1888                 let mut confirmed_txid = us.funding_spend_confirmed;
1889                 let mut confirmed_counterparty_output = us.confirmed_commitment_tx_counterparty_output;
1890                 let mut pending_commitment_tx_conf_thresh = None;
1891                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1892                         if let OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } =
1893                                 event.event
1894                         {
1895                                 confirmed_counterparty_output = commitment_tx_to_counterparty_output;
1896                                 Some((event.txid, event.confirmation_threshold()))
1897                         } else { None }
1898                 });
1899                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1900                         debug_assert!(us.funding_spend_confirmed.is_none(),
1901                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1902                         confirmed_txid = Some(txid);
1903                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1904                 }
1905
1906                 macro_rules! walk_htlcs {
1907                         ($holder_commitment: expr, $counterparty_revoked_commitment: expr, $htlc_iter: expr) => {
1908                                 for htlc in $htlc_iter {
1909                                         if htlc.transaction_output_index.is_some() {
1910
1911                                                 if let Some(bal) = us.get_htlc_balance(htlc, $holder_commitment, $counterparty_revoked_commitment, confirmed_txid) {
1912                                                         res.push(bal);
1913                                                 }
1914                                         }
1915                                 }
1916                         }
1917                 }
1918
1919                 if let Some(txid) = confirmed_txid {
1920                         let mut found_commitment_tx = false;
1921                         if let Some(counterparty_tx_htlcs) = us.counterparty_claimable_outpoints.get(&txid) {
1922                                 // First look for the to_remote output back to us.
1923                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1924                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1925                                                 if let OnchainEvent::MaturingOutput {
1926                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1927                                                 } = &event.event {
1928                                                         Some(descriptor.output.value)
1929                                                 } else { None }
1930                                         }) {
1931                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1932                                                         amount_satoshis: value,
1933                                                         confirmation_height: conf_thresh,
1934                                                 });
1935                                         } else {
1936                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1937                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1938                                                 // confirmation with the same height or have never met our dust amount.
1939                                         }
1940                                 }
1941                                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1942                                         walk_htlcs!(false, false, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1943                                 } else {
1944                                         walk_htlcs!(false, true, counterparty_tx_htlcs.iter().map(|(a, _)| a));
1945                                         // The counterparty broadcasted a revoked state!
1946                                         // Look for any StaticOutputs first, generating claimable balances for those.
1947                                         // If any match the confirmed counterparty revoked to_self output, skip
1948                                         // generating a CounterpartyRevokedOutputClaimable.
1949                                         let mut spent_counterparty_output = false;
1950                                         for event in us.onchain_events_awaiting_threshold_conf.iter() {
1951                                                 if let OnchainEvent::MaturingOutput {
1952                                                         descriptor: SpendableOutputDescriptor::StaticOutput { output, .. }
1953                                                 } = &event.event {
1954                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1955                                                                 amount_satoshis: output.value,
1956                                                                 confirmation_height: event.confirmation_threshold(),
1957                                                         });
1958                                                         if let Some(confirmed_to_self_idx) = confirmed_counterparty_output.map(|(idx, _)| idx) {
1959                                                                 if event.transaction.as_ref().map(|tx|
1960                                                                         tx.input.iter().any(|inp| inp.previous_output.vout == confirmed_to_self_idx)
1961                                                                 ).unwrap_or(false) {
1962                                                                         spent_counterparty_output = true;
1963                                                                 }
1964                                                         }
1965                                                 }
1966                                         }
1967
1968                                         if spent_counterparty_output {
1969                                         } else if let Some((confirmed_to_self_idx, amt)) = confirmed_counterparty_output {
1970                                                 let output_spendable = us.onchain_tx_handler
1971                                                         .is_output_spend_pending(&BitcoinOutPoint::new(txid, confirmed_to_self_idx));
1972                                                 if output_spendable {
1973                                                         res.push(Balance::CounterpartyRevokedOutputClaimable {
1974                                                                 amount_satoshis: amt,
1975                                                         });
1976                                                 }
1977                                         } else {
1978                                                 // Counterparty output is missing, either it was broadcasted on a
1979                                                 // previous version of LDK or the counterparty hadn't met dust.
1980                                         }
1981                                 }
1982                                 found_commitment_tx = true;
1983                         } else if txid == us.current_holder_commitment_tx.txid {
1984                                 walk_htlcs!(true, false, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1985                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1986                                         res.push(Balance::ClaimableAwaitingConfirmations {
1987                                                 amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1988                                                 confirmation_height: conf_thresh,
1989                                         });
1990                                 }
1991                                 found_commitment_tx = true;
1992                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1993                                 if txid == prev_commitment.txid {
1994                                         walk_htlcs!(true, false, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1995                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1996                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1997                                                         amount_satoshis: prev_commitment.to_self_value_sat,
1998                                                         confirmation_height: conf_thresh,
1999                                                 });
2000                                         }
2001                                         found_commitment_tx = true;
2002                                 }
2003                         }
2004                         if !found_commitment_tx {
2005                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
2006                                         // We blindly assume this is a cooperative close transaction here, and that
2007                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
2008                                         // the amount we can claim as we'll punish a misbehaving counterparty.
2009                                         res.push(Balance::ClaimableAwaitingConfirmations {
2010                                                 amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
2011                                                 confirmation_height: conf_thresh,
2012                                         });
2013                                 }
2014                         }
2015                 } else {
2016                         let mut claimable_inbound_htlc_value_sat = 0;
2017                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
2018                                 if htlc.transaction_output_index.is_none() { continue; }
2019                                 if htlc.offered {
2020                                         res.push(Balance::MaybeTimeoutClaimableHTLC {
2021                                                 amount_satoshis: htlc.amount_msat / 1000,
2022                                                 claimable_height: htlc.cltv_expiry,
2023                                                 payment_hash: htlc.payment_hash,
2024                                         });
2025                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
2026                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
2027                                 } else {
2028                                         // As long as the HTLC is still in our latest commitment state, treat
2029                                         // it as potentially claimable, even if it has long-since expired.
2030                                         res.push(Balance::MaybePreimageClaimableHTLC {
2031                                                 amount_satoshis: htlc.amount_msat / 1000,
2032                                                 expiry_height: htlc.cltv_expiry,
2033                                                 payment_hash: htlc.payment_hash,
2034                                         });
2035                                 }
2036                         }
2037                         res.push(Balance::ClaimableOnChannelClose {
2038                                 amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
2039                         });
2040                 }
2041
2042                 res
2043         }
2044
2045         /// Gets the set of outbound HTLCs which can be (or have been) resolved by this
2046         /// `ChannelMonitor`. This is used to determine if an HTLC was removed from the channel prior
2047         /// to the `ChannelManager` having been persisted.
2048         ///
2049         /// This is similar to [`Self::get_pending_or_resolved_outbound_htlcs`] except it includes
2050         /// HTLCs which were resolved on-chain (i.e. where the final HTLC resolution was done by an
2051         /// event from this `ChannelMonitor`).
2052         pub(crate) fn get_all_current_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
2053                 let mut res = HashMap::new();
2054                 // Just examine the available counterparty commitment transactions. See docs on
2055                 // `fail_unbroadcast_htlcs`, below, for justification.
2056                 let us = self.inner.lock().unwrap();
2057                 macro_rules! walk_counterparty_commitment {
2058                         ($txid: expr) => {
2059                                 if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
2060                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
2061                                                 if let &Some(ref source) = source_option {
2062                                                         res.insert((**source).clone(), (htlc.clone(),
2063                                                                 us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned()));
2064                                                 }
2065                                         }
2066                                 }
2067                         }
2068                 }
2069                 if let Some(ref txid) = us.current_counterparty_commitment_txid {
2070                         walk_counterparty_commitment!(txid);
2071                 }
2072                 if let Some(ref txid) = us.prev_counterparty_commitment_txid {
2073                         walk_counterparty_commitment!(txid);
2074                 }
2075                 res
2076         }
2077
2078         /// Gets the set of outbound HTLCs which are pending resolution in this channel or which were
2079         /// resolved with a preimage from our counterparty.
2080         ///
2081         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
2082         ///
2083         /// Currently, the preimage is unused, however if it is present in the relevant internal state
2084         /// an HTLC is always included even if it has been resolved.
2085         pub(crate) fn get_pending_or_resolved_outbound_htlcs(&self) -> HashMap<HTLCSource, (HTLCOutputInCommitment, Option<PaymentPreimage>)> {
2086                 let us = self.inner.lock().unwrap();
2087                 // We're only concerned with the confirmation count of HTLC transactions, and don't
2088                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
2089                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
2090                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
2091                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
2092                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
2093                                         Some(event.txid)
2094                                 } else { None }
2095                         })
2096                 });
2097
2098                 if confirmed_txid.is_none() {
2099                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
2100                         // closed), just get the full set.
2101                         mem::drop(us);
2102                         return self.get_all_current_outbound_htlcs();
2103                 }
2104
2105                 let mut res = HashMap::new();
2106                 macro_rules! walk_htlcs {
2107                         ($holder_commitment: expr, $htlc_iter: expr) => {
2108                                 for (htlc, source) in $htlc_iter {
2109                                         if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc.transaction_output_index) {
2110                                                 // We should assert that funding_spend_confirmed is_some() here, but we
2111                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
2112                                                 // would fail.
2113                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
2114                                                 // should assert here like we do in `get_claimable_balances`.
2115                                         } else if htlc.offered == $holder_commitment {
2116                                                 // If the payment was outbound, check if there's an HTLCUpdate
2117                                                 // indicating we have spent this HTLC with a timeout, claiming it back
2118                                                 // and awaiting confirmations on it.
2119                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
2120                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
2121                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
2122                                                                 // before considering it "no longer pending" - this matches when we
2123                                                                 // provide the ChannelManager an HTLC failure event.
2124                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
2125                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
2126                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
2127                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
2128                                                                 // immediately non-pending, matching when we provide ChannelManager
2129                                                                 // the preimage.
2130                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
2131                                                         } else { false }
2132                                                 });
2133                                                 let counterparty_resolved_preimage_opt =
2134                                                         us.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).cloned();
2135                                                 if !htlc_update_confd || counterparty_resolved_preimage_opt.is_some() {
2136                                                         res.insert(source.clone(), (htlc.clone(), counterparty_resolved_preimage_opt));
2137                                                 }
2138                                         }
2139                                 }
2140                         }
2141                 }
2142
2143                 let txid = confirmed_txid.unwrap();
2144                 if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
2145                         walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
2146                                 if let &Some(ref source) = b {
2147                                         Some((a, &**source))
2148                                 } else { None }
2149                         }));
2150                 } else if txid == us.current_holder_commitment_tx.txid {
2151                         walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
2152                                 if let Some(source) = c { Some((a, source)) } else { None }
2153                         }));
2154                 } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
2155                         if txid == prev_commitment.txid {
2156                                 walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
2157                                         if let Some(source) = c { Some((a, source)) } else { None }
2158                                 }));
2159                         }
2160                 }
2161
2162                 res
2163         }
2164
2165         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
2166                 self.inner.lock().unwrap().payment_preimages.clone()
2167         }
2168 }
2169
2170 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
2171 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
2172 /// after ANTI_REORG_DELAY blocks.
2173 ///
2174 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
2175 /// are the commitment transactions which are generated by us. The off-chain state machine in
2176 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
2177 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
2178 /// included in a remote commitment transaction are failed back if they are not present in the
2179 /// broadcasted commitment transaction.
2180 ///
2181 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
2182 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
2183 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
2184 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
2185 macro_rules! fail_unbroadcast_htlcs {
2186         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr, $commitment_tx_confirmed: expr,
2187          $commitment_tx_conf_height: expr, $commitment_tx_conf_hash: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
2188                 debug_assert_eq!($commitment_tx_confirmed.txid(), $commitment_txid_confirmed);
2189
2190                 macro_rules! check_htlc_fails {
2191                         ($txid: expr, $commitment_tx: expr) => {
2192                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
2193                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
2194                                                 if let &Some(ref source) = source_option {
2195                                                         // Check if the HTLC is present in the commitment transaction that was
2196                                                         // broadcast, but not if it was below the dust limit, which we should
2197                                                         // fail backwards immediately as there is no way for us to learn the
2198                                                         // payment_preimage.
2199                                                         // Note that if the dust limit were allowed to change between
2200                                                         // commitment transactions we'd want to be check whether *any*
2201                                                         // broadcastable commitment transaction has the HTLC in it, but it
2202                                                         // cannot currently change after channel initialization, so we don't
2203                                                         // need to here.
2204                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
2205
2206                                                         let mut matched_htlc = false;
2207                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
2208                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
2209                                                                         (Some(&**source) == *broadcast_source ||
2210                                                                          (broadcast_source.is_none() &&
2211                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
2212                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
2213                                                                         matched_htlc = true;
2214                                                                         break;
2215                                                                 }
2216                                                         }
2217                                                         if matched_htlc { continue; }
2218                                                         if $self.counterparty_fulfilled_htlcs.get(&SentHTLCId::from_source(source)).is_some() {
2219                                                                 continue;
2220                                                         }
2221                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
2222                                                                 if entry.height != $commitment_tx_conf_height { return true; }
2223                                                                 match entry.event {
2224                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
2225                                                                                 *update_source != **source
2226                                                                         },
2227                                                                         _ => true,
2228                                                                 }
2229                                                         });
2230                                                         let entry = OnchainEventEntry {
2231                                                                 txid: $commitment_txid_confirmed,
2232                                                                 transaction: Some($commitment_tx_confirmed.clone()),
2233                                                                 height: $commitment_tx_conf_height,
2234                                                                 block_hash: Some(*$commitment_tx_conf_hash),
2235                                                                 event: OnchainEvent::HTLCUpdate {
2236                                                                         source: (**source).clone(),
2237                                                                         payment_hash: htlc.payment_hash.clone(),
2238                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
2239                                                                         commitment_tx_output_idx: None,
2240                                                                 },
2241                                                         };
2242                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
2243                                                                 &htlc.payment_hash, $commitment_tx, $commitment_tx_type,
2244                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
2245                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
2246                                                 }
2247                                         }
2248                                 }
2249                         }
2250                 }
2251                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
2252                         check_htlc_fails!(txid, "current");
2253                 }
2254                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
2255                         check_htlc_fails!(txid, "previous");
2256                 }
2257         } }
2258 }
2259
2260 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
2261 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
2262 // in-line tests later.
2263
2264 #[cfg(test)]
2265 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
2266         let mut ret = [opcodes::all::OP_NOP.to_u8(); 136];
2267         ret[131] = opcodes::all::OP_DROP.to_u8();
2268         ret[132] = opcodes::all::OP_DROP.to_u8();
2269         ret[133] = opcodes::all::OP_DROP.to_u8();
2270         ret[134] = opcodes::all::OP_DROP.to_u8();
2271         ret[135] = opcodes::OP_TRUE.to_u8();
2272         Vec::from(&ret[..])
2273 }
2274
2275 #[cfg(test)]
2276 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
2277         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
2278 }
2279
2280 impl<Signer: WriteableEcdsaChannelSigner> ChannelMonitorImpl<Signer> {
2281         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
2282         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
2283         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
2284         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
2285                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
2286                         return Err("Previous secret did not match new one");
2287                 }
2288
2289                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
2290                 // events for now-revoked/fulfilled HTLCs.
2291                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
2292                         if self.current_counterparty_commitment_txid.unwrap() != txid {
2293                                 let cur_claimables = self.counterparty_claimable_outpoints.get(
2294                                         &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2295                                 for (_, ref source_opt) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2296                                         if let Some(source) = source_opt {
2297                                                 if !cur_claimables.iter()
2298                                                         .any(|(_, cur_source_opt)| cur_source_opt == source_opt)
2299                                                 {
2300                                                         self.counterparty_fulfilled_htlcs.remove(&SentHTLCId::from_source(source));
2301                                                 }
2302                                         }
2303                                 }
2304                                 for &mut (_, ref mut source_opt) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
2305                                         *source_opt = None;
2306                                 }
2307                         } else {
2308                                 assert!(cfg!(fuzzing), "Commitment txids are unique outside of fuzzing, where hashes can collide");
2309                         }
2310                 }
2311
2312                 if !self.payment_preimages.is_empty() {
2313                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
2314                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
2315                         let min_idx = self.get_min_seen_secret();
2316                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
2317
2318                         self.payment_preimages.retain(|&k, _| {
2319                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
2320                                         if k == htlc.payment_hash {
2321                                                 return true
2322                                         }
2323                                 }
2324                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
2325                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
2326                                                 if k == htlc.payment_hash {
2327                                                         return true
2328                                                 }
2329                                         }
2330                                 }
2331                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
2332                                         if *cn < min_idx {
2333                                                 return true
2334                                         }
2335                                         true
2336                                 } else { false };
2337                                 if contains {
2338                                         counterparty_hash_commitment_number.remove(&k);
2339                                 }
2340                                 false
2341                         });
2342                 }
2343
2344                 Ok(())
2345         }
2346
2347         pub(crate) fn provide_initial_counterparty_commitment_tx<L: Deref>(
2348                 &mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
2349                 commitment_number: u64, their_per_commitment_point: PublicKey, feerate_per_kw: u32,
2350                 to_broadcaster_value: u64, to_countersignatory_value: u64, logger: &L
2351         )
2352         where L::Target: Logger
2353         {
2354                 self.initial_counterparty_commitment_info = Some((their_per_commitment_point.clone(),
2355                         feerate_per_kw, to_broadcaster_value, to_countersignatory_value));
2356
2357                 #[cfg(debug_assertions)] {
2358                         let rebuilt_commitment_tx = self.initial_counterparty_commitment_tx().unwrap();
2359                         debug_assert_eq!(rebuilt_commitment_tx.trust().txid(), txid);
2360                 }
2361
2362                 self.provide_latest_counterparty_commitment_tx(txid, htlc_outputs, commitment_number,
2363                                 their_per_commitment_point, logger);
2364         }
2365
2366         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 {
2367                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
2368                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
2369                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
2370                 // timeouts)
2371                 for &(ref htlc, _) in &htlc_outputs {
2372                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
2373                 }
2374
2375                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
2376                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
2377                 self.current_counterparty_commitment_txid = Some(txid);
2378                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
2379                 self.current_counterparty_commitment_number = commitment_number;
2380                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
2381                 match self.their_cur_per_commitment_points {
2382                         Some(old_points) => {
2383                                 if old_points.0 == commitment_number + 1 {
2384                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
2385                                 } else if old_points.0 == commitment_number + 2 {
2386                                         if let Some(old_second_point) = old_points.2 {
2387                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
2388                                         } else {
2389                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2390                                         }
2391                                 } else {
2392                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2393                                 }
2394                         },
2395                         None => {
2396                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
2397                         }
2398                 }
2399                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
2400                 for htlc in htlc_outputs {
2401                         if htlc.0.transaction_output_index.is_some() {
2402                                 htlcs.push(htlc.0);
2403                         }
2404                 }
2405         }
2406
2407         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
2408         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
2409         /// is important that any clones of this channel monitor (including remote clones) by kept
2410         /// up-to-date as our holder commitment transaction is updated.
2411         /// Panics if set_on_holder_tx_csv has never been called.
2412         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> {
2413                 if htlc_outputs.iter().any(|(_, s, _)| s.is_some()) {
2414                         // If we have non-dust HTLCs in htlc_outputs, ensure they match the HTLCs in the
2415                         // `holder_commitment_tx`. In the future, we'll no longer provide the redundant data
2416                         // and just pass in source data via `nondust_htlc_sources`.
2417                         debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.trust().htlcs().len());
2418                         for (a, b) in htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).map(|(h, _, _)| h).zip(holder_commitment_tx.trust().htlcs().iter()) {
2419                                 debug_assert_eq!(a, b);
2420                         }
2421                         debug_assert_eq!(htlc_outputs.iter().filter(|(_, s, _)| s.is_some()).count(), holder_commitment_tx.counterparty_htlc_sigs.len());
2422                         for (a, b) in htlc_outputs.iter().filter_map(|(_, s, _)| s.as_ref()).zip(holder_commitment_tx.counterparty_htlc_sigs.iter()) {
2423                                 debug_assert_eq!(a, b);
2424                         }
2425                         debug_assert!(nondust_htlc_sources.is_empty());
2426                 } else {
2427                         // If we don't have any non-dust HTLCs in htlc_outputs, assume they were all passed via
2428                         // `nondust_htlc_sources`, building up the final htlc_outputs by combining
2429                         // `nondust_htlc_sources` and the `holder_commitment_tx`
2430                         #[cfg(debug_assertions)] {
2431                                 let mut prev = -1;
2432                                 for htlc in holder_commitment_tx.trust().htlcs().iter() {
2433                                         assert!(htlc.transaction_output_index.unwrap() as i32 > prev);
2434                                         prev = htlc.transaction_output_index.unwrap() as i32;
2435                                 }
2436                         }
2437                         debug_assert!(htlc_outputs.iter().all(|(htlc, _, _)| htlc.transaction_output_index.is_none()));
2438                         debug_assert!(htlc_outputs.iter().all(|(_, sig_opt, _)| sig_opt.is_none()));
2439                         debug_assert_eq!(holder_commitment_tx.trust().htlcs().len(), holder_commitment_tx.counterparty_htlc_sigs.len());
2440
2441                         let mut sources_iter = nondust_htlc_sources.into_iter();
2442
2443                         for (htlc, counterparty_sig) in holder_commitment_tx.trust().htlcs().iter()
2444                                 .zip(holder_commitment_tx.counterparty_htlc_sigs.iter())
2445                         {
2446                                 if htlc.offered {
2447                                         let source = sources_iter.next().expect("Non-dust HTLC sources didn't match commitment tx");
2448                                         #[cfg(debug_assertions)] {
2449                                                 assert!(source.possibly_matches_output(htlc));
2450                                         }
2451                                         htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), Some(source)));
2452                                 } else {
2453                                         htlc_outputs.push((htlc.clone(), Some(counterparty_sig.clone()), None));
2454                                 }
2455                         }
2456                         debug_assert!(sources_iter.next().is_none());
2457                 }
2458
2459                 let trusted_tx = holder_commitment_tx.trust();
2460                 let txid = trusted_tx.txid();
2461                 let tx_keys = trusted_tx.keys();
2462                 self.current_holder_commitment_number = trusted_tx.commitment_number();
2463                 let mut new_holder_commitment_tx = HolderSignedTx {
2464                         txid,
2465                         revocation_key: tx_keys.revocation_key,
2466                         a_htlc_key: tx_keys.broadcaster_htlc_key,
2467                         b_htlc_key: tx_keys.countersignatory_htlc_key,
2468                         delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
2469                         per_commitment_point: tx_keys.per_commitment_point,
2470                         htlc_outputs,
2471                         to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
2472                         feerate_per_kw: trusted_tx.feerate_per_kw(),
2473                 };
2474                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
2475                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
2476                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
2477                 for (claimed_htlc_id, claimed_preimage) in claimed_htlcs {
2478                         #[cfg(debug_assertions)] {
2479                                 let cur_counterparty_htlcs = self.counterparty_claimable_outpoints.get(
2480                                                 &self.current_counterparty_commitment_txid.unwrap()).unwrap();
2481                                 assert!(cur_counterparty_htlcs.iter().any(|(_, source_opt)| {
2482                                         if let Some(source) = source_opt {
2483                                                 SentHTLCId::from_source(source) == *claimed_htlc_id
2484                                         } else { false }
2485                                 }));
2486                         }
2487                         self.counterparty_fulfilled_htlcs.insert(*claimed_htlc_id, *claimed_preimage);
2488                 }
2489                 if self.holder_tx_signed {
2490                         return Err("Latest holder commitment signed has already been signed, update is rejected");
2491                 }
2492                 Ok(())
2493         }
2494
2495         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
2496         /// commitment_tx_infos which contain the payment hash have been revoked.
2497         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
2498                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
2499                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
2500         where B::Target: BroadcasterInterface,
2501                     F::Target: FeeEstimator,
2502                     L::Target: Logger,
2503         {
2504                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
2505
2506                 // If the channel is force closed, try to claim the output from this preimage.
2507                 // First check if a counterparty commitment transaction has been broadcasted:
2508                 macro_rules! claim_htlcs {
2509                         ($commitment_number: expr, $txid: expr) => {
2510                                 let (htlc_claim_reqs, _) = self.get_counterparty_output_claim_info($commitment_number, $txid, None);
2511                                 self.onchain_tx_handler.update_claims_view_from_requests(htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2512                         }
2513                 }
2514                 if let Some(txid) = self.current_counterparty_commitment_txid {
2515                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2516                                 claim_htlcs!(*commitment_number, txid);
2517                                 return;
2518                         }
2519                 }
2520                 if let Some(txid) = self.prev_counterparty_commitment_txid {
2521                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
2522                                 claim_htlcs!(*commitment_number, txid);
2523                                 return;
2524                         }
2525                 }
2526
2527                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
2528                 // claiming the HTLC output from each of the holder commitment transactions.
2529                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
2530                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
2531                 // holder commitment transactions.
2532                 if self.broadcasted_holder_revokable_script.is_some() {
2533                         // Assume that the broadcasted commitment transaction confirmed in the current best
2534                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
2535                         // transactions.
2536                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2537                         self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2538                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
2539                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
2540                                 self.onchain_tx_handler.update_claims_view_from_requests(claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
2541                         }
2542                 }
2543         }
2544
2545         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
2546                 where B::Target: BroadcasterInterface,
2547                                         L::Target: Logger,
2548         {
2549                 let commit_txs = self.get_latest_holder_commitment_txn(logger);
2550                 let mut txs = vec![];
2551                 for tx in commit_txs.iter() {
2552                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
2553                         txs.push(tx);
2554                 }
2555                 broadcaster.broadcast_transactions(&txs);
2556                 self.pending_monitor_events.push(MonitorEvent::HolderForceClosed(self.funding_info.0));
2557         }
2558
2559         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: F, logger: &L) -> Result<(), ()>
2560         where B::Target: BroadcasterInterface,
2561                 F::Target: FeeEstimator,
2562                 L::Target: Logger,
2563         {
2564                 if self.latest_update_id == CLOSED_CHANNEL_UPDATE_ID && updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2565                         log_info!(logger, "Applying post-force-closed update to monitor {} with {} change(s).",
2566                                 log_funding_info!(self), updates.updates.len());
2567                 } else if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2568                         log_info!(logger, "Applying force close update to monitor {} with {} change(s).",
2569                                 log_funding_info!(self), updates.updates.len());
2570                 } else {
2571                         log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} change(s).",
2572                                 log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
2573                 }
2574                 // ChannelMonitor updates may be applied after force close if we receive a preimage for a
2575                 // broadcasted commitment transaction HTLC output that we'd like to claim on-chain. If this
2576                 // is the case, we no longer have guaranteed access to the monitor's update ID, so we use a
2577                 // sentinel value instead.
2578                 //
2579                 // The `ChannelManager` may also queue redundant `ChannelForceClosed` updates if it still
2580                 // thinks the channel needs to have its commitment transaction broadcast, so we'll allow
2581                 // them as well.
2582                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
2583                         assert_eq!(updates.updates.len(), 1);
2584                         match updates.updates[0] {
2585                                 ChannelMonitorUpdateStep::ChannelForceClosed { .. } => {},
2586                                 // We should have already seen a `ChannelForceClosed` update if we're trying to
2587                                 // provide a preimage at this point.
2588                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } =>
2589                                         debug_assert_eq!(self.latest_update_id, CLOSED_CHANNEL_UPDATE_ID),
2590                                 _ => {
2591                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
2592                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
2593                                 },
2594                         }
2595                 } else if self.latest_update_id + 1 != updates.update_id {
2596                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
2597                 }
2598                 let mut ret = Ok(());
2599                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&*fee_estimator);
2600                 for update in updates.updates.iter() {
2601                         match update {
2602                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, claimed_htlcs, nondust_htlc_sources } => {
2603                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
2604                                         if self.lockdown_from_offchain { panic!(); }
2605                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone(), &claimed_htlcs, nondust_htlc_sources.clone()) {
2606                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
2607                                                 log_error!(logger, "    {}", e);
2608                                                 ret = Err(());
2609                                         }
2610                                 }
2611                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point, .. } => {
2612                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
2613                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
2614                                 },
2615                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
2616                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
2617                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
2618                                 },
2619                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
2620                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
2621                                         if let Err(e) = self.provide_secret(*idx, *secret) {
2622                                                 debug_assert!(false, "Latest counterparty commitment secret was invalid");
2623                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
2624                                                 log_error!(logger, "    {}", e);
2625                                                 ret = Err(());
2626                                         }
2627                                 },
2628                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2629                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2630                                         self.lockdown_from_offchain = true;
2631                                         if *should_broadcast {
2632                                                 // There's no need to broadcast our commitment transaction if we've seen one
2633                                                 // confirmed (even with 1 confirmation) as it'll be rejected as
2634                                                 // duplicate/conflicting.
2635                                                 let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
2636                                                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
2637                                                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
2638                                                                 _ => false,
2639                                                         }).is_some();
2640                                                 if detected_funding_spend {
2641                                                         log_trace!(logger, "Avoiding commitment broadcast, already detected confirmed spend onchain");
2642                                                         continue;
2643                                                 }
2644                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2645                                                 // If the channel supports anchor outputs, we'll need to emit an external
2646                                                 // event to be consumed such that a child transaction is broadcast with a
2647                                                 // high enough feerate for the parent commitment transaction to confirm.
2648                                                 if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
2649                                                         let funding_output = HolderFundingOutput::build(
2650                                                                 self.funding_redeemscript.clone(), self.channel_value_satoshis,
2651                                                                 self.onchain_tx_handler.channel_type_features().clone(),
2652                                                         );
2653                                                         let best_block_height = self.best_block.height();
2654                                                         let commitment_package = PackageTemplate::build_package(
2655                                                                 self.funding_info.0.txid.clone(), self.funding_info.0.index as u32,
2656                                                                 PackageSolvingData::HolderFundingOutput(funding_output),
2657                                                                 best_block_height, best_block_height
2658                                                         );
2659                                                         self.onchain_tx_handler.update_claims_view_from_requests(
2660                                                                 vec![commitment_package], best_block_height, best_block_height,
2661                                                                 broadcaster, &bounded_fee_estimator, logger,
2662                                                         );
2663                                                 }
2664                                         } else if !self.holder_tx_signed {
2665                                                 log_error!(logger, "WARNING: You have a potentially-unsafe holder commitment transaction available to broadcast");
2666                                                 log_error!(logger, "    in channel monitor for channel {}!", &self.funding_info.0.to_channel_id());
2667                                                 log_error!(logger, "    Read the docs for ChannelMonitor::get_latest_holder_commitment_txn and take manual action!");
2668                                         } else {
2669                                                 // If we generated a MonitorEvent::HolderForceClosed, the ChannelManager
2670                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2671                                                 // shouldn't print the scary warning above.
2672                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2673                                         }
2674                                 },
2675                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2676                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2677                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2678                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2679                                         }
2680                                 },
2681                         }
2682                 }
2683
2684                 #[cfg(debug_assertions)] {
2685                         self.counterparty_commitment_txs_from_update(updates);
2686                 }
2687
2688                 // If the updates succeeded and we were in an already closed channel state, then there's no
2689                 // need to refuse any updates we expect to receive afer seeing a confirmed commitment.
2690                 if ret.is_ok() && updates.update_id == CLOSED_CHANNEL_UPDATE_ID && self.latest_update_id == updates.update_id {
2691                         return Ok(());
2692                 }
2693
2694                 self.latest_update_id = updates.update_id;
2695
2696                 // Refuse updates after we've detected a spend onchain, but only if we haven't processed a
2697                 // force closed monitor update yet.
2698                 if ret.is_ok() && self.funding_spend_seen && self.latest_update_id != CLOSED_CHANNEL_UPDATE_ID {
2699                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2700                         Err(())
2701                 } else { ret }
2702         }
2703
2704         pub fn get_latest_update_id(&self) -> u64 {
2705                 self.latest_update_id
2706         }
2707
2708         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2709                 &self.funding_info
2710         }
2711
2712         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2713                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2714                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2715                 // its trivial to do, double-check that here.
2716                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2717                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2718                 }
2719                 &self.outputs_to_watch
2720         }
2721
2722         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2723                 let mut ret = Vec::new();
2724                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2725                 ret
2726         }
2727
2728         /// Gets the set of events that are repeated regularly (e.g. those which RBF bump
2729         /// transactions). We're okay if we lose these on restart as they'll be regenerated for us at
2730         /// some regular interval via [`ChannelMonitor::rebroadcast_pending_claims`].
2731         pub(super) fn get_repeated_events(&mut self) -> Vec<Event> {
2732                 let pending_claim_events = self.onchain_tx_handler.get_and_clear_pending_claim_events();
2733                 let mut ret = Vec::with_capacity(pending_claim_events.len());
2734                 for (claim_id, claim_event) in pending_claim_events {
2735                         match claim_event {
2736                                 ClaimEvent::BumpCommitment {
2737                                         package_target_feerate_sat_per_1000_weight, commitment_tx, anchor_output_idx,
2738                                 } => {
2739                                         let commitment_txid = commitment_tx.txid();
2740                                         debug_assert_eq!(self.current_holder_commitment_tx.txid, commitment_txid);
2741                                         let pending_htlcs = self.current_holder_commitment_tx.non_dust_htlcs();
2742                                         let commitment_tx_fee_satoshis = self.channel_value_satoshis -
2743                                                 commitment_tx.output.iter().fold(0u64, |sum, output| sum + output.value);
2744                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::ChannelClose {
2745                                                 claim_id,
2746                                                 package_target_feerate_sat_per_1000_weight,
2747                                                 commitment_tx,
2748                                                 commitment_tx_fee_satoshis,
2749                                                 anchor_descriptor: AnchorDescriptor {
2750                                                         channel_derivation_parameters: ChannelDerivationParameters {
2751                                                                 keys_id: self.channel_keys_id,
2752                                                                 value_satoshis: self.channel_value_satoshis,
2753                                                                 transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2754                                                         },
2755                                                         outpoint: BitcoinOutPoint {
2756                                                                 txid: commitment_txid,
2757                                                                 vout: anchor_output_idx,
2758                                                         },
2759                                                 },
2760                                                 pending_htlcs,
2761                                         }));
2762                                 },
2763                                 ClaimEvent::BumpHTLC {
2764                                         target_feerate_sat_per_1000_weight, htlcs, tx_lock_time,
2765                                 } => {
2766                                         let mut htlc_descriptors = Vec::with_capacity(htlcs.len());
2767                                         for htlc in htlcs {
2768                                                 htlc_descriptors.push(HTLCDescriptor {
2769                                                         channel_derivation_parameters: ChannelDerivationParameters {
2770                                                                 keys_id: self.channel_keys_id,
2771                                                                 value_satoshis: self.channel_value_satoshis,
2772                                                                 transaction_parameters: self.onchain_tx_handler.channel_transaction_parameters.clone(),
2773                                                         },
2774                                                         commitment_txid: htlc.commitment_txid,
2775                                                         per_commitment_number: htlc.per_commitment_number,
2776                                                         per_commitment_point: self.onchain_tx_handler.signer.get_per_commitment_point(
2777                                                                 htlc.per_commitment_number, &self.onchain_tx_handler.secp_ctx,
2778                                                         ),
2779                                                         htlc: htlc.htlc,
2780                                                         preimage: htlc.preimage,
2781                                                         counterparty_sig: htlc.counterparty_sig,
2782                                                 });
2783                                         }
2784                                         ret.push(Event::BumpTransaction(BumpTransactionEvent::HTLCResolution {
2785                                                 claim_id,
2786                                                 target_feerate_sat_per_1000_weight,
2787                                                 htlc_descriptors,
2788                                                 tx_lock_time,
2789                                         }));
2790                                 }
2791                         }
2792                 }
2793                 ret
2794         }
2795
2796         pub(crate) fn initial_counterparty_commitment_tx(&mut self) -> Option<CommitmentTransaction> {
2797                 let (their_per_commitment_point, feerate_per_kw, to_broadcaster_value,
2798                         to_countersignatory_value) = self.initial_counterparty_commitment_info?;
2799                 let htlc_outputs = vec![];
2800
2801                 let commitment_tx = self.build_counterparty_commitment_tx(INITIAL_COMMITMENT_NUMBER,
2802                         &their_per_commitment_point, to_broadcaster_value, to_countersignatory_value,
2803                         feerate_per_kw, htlc_outputs);
2804                 Some(commitment_tx)
2805         }
2806
2807         fn build_counterparty_commitment_tx(
2808                 &self, commitment_number: u64, their_per_commitment_point: &PublicKey,
2809                 to_broadcaster_value: u64, to_countersignatory_value: u64, feerate_per_kw: u32,
2810                 mut nondust_htlcs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>
2811         ) -> CommitmentTransaction {
2812                 let broadcaster_keys = &self.onchain_tx_handler.channel_transaction_parameters
2813                         .counterparty_parameters.as_ref().unwrap().pubkeys;
2814                 let countersignatory_keys =
2815                         &self.onchain_tx_handler.channel_transaction_parameters.holder_pubkeys;
2816
2817                 let broadcaster_funding_key = broadcaster_keys.funding_pubkey;
2818                 let countersignatory_funding_key = countersignatory_keys.funding_pubkey;
2819                 let keys = TxCreationKeys::from_channel_static_keys(&their_per_commitment_point,
2820                         &broadcaster_keys, &countersignatory_keys, &self.onchain_tx_handler.secp_ctx);
2821                 let channel_parameters =
2822                         &self.onchain_tx_handler.channel_transaction_parameters.as_counterparty_broadcastable();
2823
2824                 CommitmentTransaction::new_with_auxiliary_htlc_data(commitment_number,
2825                         to_broadcaster_value, to_countersignatory_value, broadcaster_funding_key,
2826                         countersignatory_funding_key, keys, feerate_per_kw, &mut nondust_htlcs,
2827                         channel_parameters)
2828         }
2829
2830         pub(crate) fn counterparty_commitment_txs_from_update(&self, update: &ChannelMonitorUpdate) -> Vec<CommitmentTransaction> {
2831                 update.updates.iter().filter_map(|update| {
2832                         match update {
2833                                 &ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid,
2834                                         ref htlc_outputs, commitment_number, their_per_commitment_point,
2835                                         feerate_per_kw: Some(feerate_per_kw),
2836                                         to_broadcaster_value_sat: Some(to_broadcaster_value),
2837                                         to_countersignatory_value_sat: Some(to_countersignatory_value) } => {
2838
2839                                         let nondust_htlcs = htlc_outputs.iter().filter_map(|(htlc, _)| {
2840                                                 htlc.transaction_output_index.map(|_| (htlc.clone(), None))
2841                                         }).collect::<Vec<_>>();
2842
2843                                         let commitment_tx = self.build_counterparty_commitment_tx(commitment_number,
2844                                                         &their_per_commitment_point, to_broadcaster_value,
2845                                                         to_countersignatory_value, feerate_per_kw, nondust_htlcs);
2846
2847                                         debug_assert_eq!(commitment_tx.trust().txid(), commitment_txid);
2848
2849                                         Some(commitment_tx)
2850                                 },
2851                                 _ => None,
2852                         }
2853                 }).collect()
2854         }
2855
2856         pub(crate) fn sign_to_local_justice_tx(
2857                 &self, mut justice_tx: Transaction, input_idx: usize, value: u64, commitment_number: u64
2858         ) -> Result<Transaction, ()> {
2859                 let secret = self.get_secret(commitment_number).ok_or(())?;
2860                 let per_commitment_key = SecretKey::from_slice(&secret).map_err(|_| ())?;
2861                 let their_per_commitment_point = PublicKey::from_secret_key(
2862                         &self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2863
2864                 let revocation_pubkey = chan_utils::derive_public_revocation_key(
2865                         &self.onchain_tx_handler.secp_ctx, &their_per_commitment_point,
2866                         &self.holder_revocation_basepoint);
2867                 let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
2868                         &their_per_commitment_point,
2869                         &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
2870                 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
2871                         self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2872
2873                 let sig = self.onchain_tx_handler.signer.sign_justice_revoked_output(
2874                         &justice_tx, input_idx, value, &per_commitment_key, &self.onchain_tx_handler.secp_ctx)?;
2875                 justice_tx.input[input_idx].witness.push_bitcoin_signature(&sig.serialize_der(), EcdsaSighashType::All);
2876                 justice_tx.input[input_idx].witness.push(&[1u8]);
2877                 justice_tx.input[input_idx].witness.push(revokeable_redeemscript.as_bytes());
2878                 Ok(justice_tx)
2879         }
2880
2881         /// Can only fail if idx is < get_min_seen_secret
2882         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2883                 self.commitment_secrets.get_secret(idx)
2884         }
2885
2886         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2887                 self.commitment_secrets.get_min_seen_secret()
2888         }
2889
2890         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2891                 self.current_counterparty_commitment_number
2892         }
2893
2894         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2895                 self.current_holder_commitment_number
2896         }
2897
2898         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2899         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2900         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2901         /// HTLC-Success/HTLC-Timeout transactions.
2902         ///
2903         /// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
2904         /// general information about the output that is to the counterparty in the commitment
2905         /// transaction.
2906         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
2907                 -> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
2908         where L::Target: Logger {
2909                 // Most secp and related errors trying to create keys means we have no hope of constructing
2910                 // a spend transaction...so we return no transactions to broadcast
2911                 let mut claimable_outpoints = Vec::new();
2912                 let mut watch_outputs = Vec::new();
2913                 let mut to_counterparty_output_info = None;
2914
2915                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2916                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2917
2918                 macro_rules! ignore_error {
2919                         ( $thing : expr ) => {
2920                                 match $thing {
2921                                         Ok(a) => a,
2922                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
2923                                 }
2924                         };
2925                 }
2926
2927                 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);
2928                 if commitment_number >= self.get_min_seen_secret() {
2929                         let secret = self.get_secret(commitment_number).unwrap();
2930                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2931                         let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
2932                         let revocation_pubkey = chan_utils::derive_public_revocation_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
2933                         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);
2934
2935                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2936                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2937
2938                         // First, process non-htlc outputs (to_holder & to_counterparty)
2939                         for (idx, outp) in tx.output.iter().enumerate() {
2940                                 if outp.script_pubkey == revokeable_p2wsh {
2941                                         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.channel_type_features().supports_anchors_zero_fee_htlc_tx());
2942                                         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);
2943                                         claimable_outpoints.push(justice_package);
2944                                         to_counterparty_output_info =
2945                                                 Some((idx.try_into().expect("Txn can't have more than 2^32 outputs"), outp.value));
2946                                 }
2947                         }
2948
2949                         // Then, try to find revoked htlc outputs
2950                         if let Some(ref per_commitment_data) = per_commitment_option {
2951                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2952                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2953                                                 if transaction_output_index as usize >= tx.output.len() ||
2954                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2955                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
2956                                                         return (claimable_outpoints, (commitment_txid, watch_outputs),
2957                                                                 to_counterparty_output_info);
2958                                                 }
2959                                                 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.channel_type_features);
2960                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, height);
2961                                                 claimable_outpoints.push(justice_package);
2962                                         }
2963                                 }
2964                         }
2965
2966                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2967                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2968                                 // We're definitely a counterparty commitment transaction!
2969                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2970                                 for (idx, outp) in tx.output.iter().enumerate() {
2971                                         watch_outputs.push((idx as u32, outp.clone()));
2972                                 }
2973                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2974
2975                                 if let Some(per_commitment_data) = per_commitment_option {
2976                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, tx, height,
2977                                                 block_hash, per_commitment_data.iter().map(|(htlc, htlc_source)|
2978                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2979                                                 ), logger);
2980                                 } else {
2981                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2982                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, tx, height,
2983                                                 block_hash, [].iter().map(|reference| *reference), logger);
2984                                 }
2985                         }
2986                 } else if let Some(per_commitment_data) = per_commitment_option {
2987                         // While this isn't useful yet, there is a potential race where if a counterparty
2988                         // revokes a state at the same time as the commitment transaction for that state is
2989                         // confirmed, and the watchtower receives the block before the user, the user could
2990                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2991                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2992                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2993                         // insert it here.
2994                         for (idx, outp) in tx.output.iter().enumerate() {
2995                                 watch_outputs.push((idx as u32, outp.clone()));
2996                         }
2997                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2998
2999                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
3000                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, tx, height, block_hash,
3001                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
3002                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
3003                                 ), logger);
3004
3005                         let (htlc_claim_reqs, counterparty_output_info) =
3006                                 self.get_counterparty_output_claim_info(commitment_number, commitment_txid, Some(tx));
3007                         to_counterparty_output_info = counterparty_output_info;
3008                         for req in htlc_claim_reqs {
3009                                 claimable_outpoints.push(req);
3010                         }
3011
3012                 }
3013                 (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
3014         }
3015
3016         /// Returns the HTLC claim package templates and the counterparty output info
3017         fn get_counterparty_output_claim_info(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>)
3018         -> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo) {
3019                 let mut claimable_outpoints = Vec::new();
3020                 let mut to_counterparty_output_info: CommitmentTxCounterpartyOutputInfo = None;
3021
3022                 let htlc_outputs = match self.counterparty_claimable_outpoints.get(&commitment_txid) {
3023                         Some(outputs) => outputs,
3024                         None => return (claimable_outpoints, to_counterparty_output_info),
3025                 };
3026                 let per_commitment_points = match self.their_cur_per_commitment_points {
3027                         Some(points) => points,
3028                         None => return (claimable_outpoints, to_counterparty_output_info),
3029                 };
3030
3031                 let per_commitment_point =
3032                         // If the counterparty commitment tx is the latest valid state, use their latest
3033                         // per-commitment point
3034                         if per_commitment_points.0 == commitment_number { &per_commitment_points.1 }
3035                         else if let Some(point) = per_commitment_points.2.as_ref() {
3036                                 // If counterparty commitment tx is the state previous to the latest valid state, use
3037                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
3038                                 // them to temporarily have two valid commitment txns from our viewpoint)
3039                                 if per_commitment_points.0 == commitment_number + 1 {
3040                                         point
3041                                 } else { return (claimable_outpoints, to_counterparty_output_info); }
3042                         } else { return (claimable_outpoints, to_counterparty_output_info); };
3043
3044                 if let Some(transaction) = tx {
3045                         let revocation_pubkey = chan_utils::derive_public_revocation_key(
3046                                 &self.onchain_tx_handler.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint);
3047                         let delayed_key = chan_utils::derive_public_key(&self.onchain_tx_handler.secp_ctx,
3048                                 &per_commitment_point,
3049                                 &self.counterparty_commitment_params.counterparty_delayed_payment_base_key);
3050                         let revokeable_p2wsh = chan_utils::get_revokeable_redeemscript(&revocation_pubkey,
3051                                 self.counterparty_commitment_params.on_counterparty_tx_csv,
3052                                 &delayed_key).to_v0_p2wsh();
3053                         for (idx, outp) in transaction.output.iter().enumerate() {
3054                                 if outp.script_pubkey == revokeable_p2wsh {
3055                                         to_counterparty_output_info =
3056                                                 Some((idx.try_into().expect("Can't have > 2^32 outputs"), outp.value));
3057                                 }
3058                         }
3059                 }
3060
3061                 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
3062                         if let Some(transaction_output_index) = htlc.transaction_output_index {
3063                                 if let Some(transaction) = tx {
3064                                         if transaction_output_index as usize >= transaction.output.len() ||
3065                                                 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
3066                                                         // per_commitment_data is corrupt or our commitment signing key leaked!
3067                                                         return (claimable_outpoints, to_counterparty_output_info);
3068                                                 }
3069                                 }
3070                                 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
3071                                 if preimage.is_some() || !htlc.offered {
3072                                         let counterparty_htlc_outp = if htlc.offered {
3073                                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(
3074                                                         CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
3075                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
3076                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
3077                                                                 preimage.unwrap(), htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
3078                                         } else {
3079                                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(
3080                                                         CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
3081                                                                 self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
3082                                                                 self.counterparty_commitment_params.counterparty_htlc_base_key,
3083                                                                 htlc.clone(), self.onchain_tx_handler.channel_type_features().clone()))
3084                                         };
3085                                         let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry, 0);
3086                                         claimable_outpoints.push(counterparty_package);
3087                                 }
3088                         }
3089                 }
3090
3091                 (claimable_outpoints, to_counterparty_output_info)
3092         }
3093
3094         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
3095         fn check_spend_counterparty_htlc<L: Deref>(
3096                 &mut self, tx: &Transaction, commitment_number: u64, commitment_txid: &Txid, height: u32, logger: &L
3097         ) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
3098                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
3099                 let per_commitment_key = match SecretKey::from_slice(&secret) {
3100                         Ok(key) => key,
3101                         Err(_) => return (Vec::new(), None)
3102                 };
3103                 let per_commitment_point = PublicKey::from_secret_key(&self.onchain_tx_handler.secp_ctx, &per_commitment_key);
3104
3105                 let htlc_txid = tx.txid();
3106                 let mut claimable_outpoints = vec![];
3107                 let mut outputs_to_watch = None;
3108                 // Previously, we would only claim HTLCs from revoked HTLC transactions if they had 1 input
3109                 // with a witness of 5 elements and 1 output. This wasn't enough for anchor outputs, as the
3110                 // counterparty can now aggregate multiple HTLCs into a single transaction thanks to
3111                 // `SIGHASH_SINGLE` remote signatures, leading us to not claim any HTLCs upon seeing a
3112                 // confirmed revoked HTLC transaction (for more details, see
3113                 // https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-April/003561.html).
3114                 //
3115                 // We make sure we're not vulnerable to this case by checking all inputs of the transaction,
3116                 // and claim those which spend the commitment transaction, have a witness of 5 elements, and
3117                 // have a corresponding output at the same index within the transaction.
3118                 for (idx, input) in tx.input.iter().enumerate() {
3119                         if input.previous_output.txid == *commitment_txid && input.witness.len() == 5 && tx.output.get(idx).is_some() {
3120                                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, idx);
3121                                 let revk_outp = RevokedOutput::build(
3122                                         per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
3123                                         self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key,
3124                                         tx.output[idx].value, self.counterparty_commitment_params.on_counterparty_tx_csv,
3125                                         false
3126                                 );
3127                                 let justice_package = PackageTemplate::build_package(
3128                                         htlc_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp),
3129                                         height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, height
3130                                 );
3131                                 claimable_outpoints.push(justice_package);
3132                                 if outputs_to_watch.is_none() {
3133                                         outputs_to_watch = Some((htlc_txid, vec![]));
3134                                 }
3135                                 outputs_to_watch.as_mut().unwrap().1.push((idx as u32, tx.output[idx].clone()));
3136                         }
3137                 }
3138                 (claimable_outpoints, outputs_to_watch)
3139         }
3140
3141         // Returns (1) `PackageTemplate`s that can be given to the OnchainTxHandler, so that the handler can
3142         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
3143         // script so we can detect whether a holder transaction has been seen on-chain.
3144         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
3145                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
3146
3147                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
3148                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
3149
3150                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
3151                         if let Some(transaction_output_index) = htlc.transaction_output_index {
3152                                 let htlc_output = if htlc.offered {
3153                                         let htlc_output = HolderHTLCOutput::build_offered(
3154                                                 htlc.amount_msat, htlc.cltv_expiry, self.onchain_tx_handler.channel_type_features().clone()
3155                                         );
3156                                         htlc_output
3157                                 } else {
3158                                         let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
3159                                                 preimage.clone()
3160                                         } else {
3161                                                 // We can't build an HTLC-Success transaction without the preimage
3162                                                 continue;
3163                                         };
3164                                         let htlc_output = HolderHTLCOutput::build_accepted(
3165                                                 payment_preimage, htlc.amount_msat, self.onchain_tx_handler.channel_type_features().clone()
3166                                         );
3167                                         htlc_output
3168                                 };
3169                                 let htlc_package = PackageTemplate::build_package(
3170                                         holder_tx.txid, transaction_output_index,
3171                                         PackageSolvingData::HolderHTLCOutput(htlc_output),
3172                                         htlc.cltv_expiry, conf_height
3173                                 );
3174                                 claim_requests.push(htlc_package);
3175                         }
3176                 }
3177
3178                 (claim_requests, broadcasted_holder_revokable_script)
3179         }
3180
3181         // Returns holder HTLC outputs to watch and react to in case of spending.
3182         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
3183                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
3184                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
3185                         if let Some(transaction_output_index) = htlc.transaction_output_index {
3186                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
3187                         }
3188                 }
3189                 watch_outputs
3190         }
3191
3192         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
3193         /// revoked using data in holder_claimable_outpoints.
3194         /// Should not be used if check_spend_revoked_transaction succeeds.
3195         /// Returns None unless the transaction is definitely one of our commitment transactions.
3196         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 {
3197                 let commitment_txid = tx.txid();
3198                 let mut claim_requests = Vec::new();
3199                 let mut watch_outputs = Vec::new();
3200
3201                 macro_rules! append_onchain_update {
3202                         ($updates: expr, $to_watch: expr) => {
3203                                 claim_requests = $updates.0;
3204                                 self.broadcasted_holder_revokable_script = $updates.1;
3205                                 watch_outputs.append(&mut $to_watch);
3206                         }
3207                 }
3208
3209                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
3210                 let mut is_holder_tx = false;
3211
3212                 if self.current_holder_commitment_tx.txid == commitment_txid {
3213                         is_holder_tx = true;
3214                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
3215                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
3216                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
3217                         append_onchain_update!(res, to_watch);
3218                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, tx, height,
3219                                 block_hash, self.current_holder_commitment_tx.htlc_outputs.iter()
3220                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
3221                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
3222                         if holder_tx.txid == commitment_txid {
3223                                 is_holder_tx = true;
3224                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
3225                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
3226                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
3227                                 append_onchain_update!(res, to_watch);
3228                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, tx, height, block_hash,
3229                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
3230                                         logger);
3231                         }
3232                 }
3233
3234                 if is_holder_tx {
3235                         Some((claim_requests, (commitment_txid, watch_outputs)))
3236                 } else {
3237                         None
3238                 }
3239         }
3240
3241         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
3242                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
3243                 self.holder_tx_signed = true;
3244                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
3245                 let txid = commitment_tx.txid();
3246                 let mut holder_transactions = vec![commitment_tx];
3247                 // When anchor outputs are present, the HTLC transactions are only valid once the commitment
3248                 // transaction confirms.
3249                 if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
3250                         return holder_transactions;
3251                 }
3252                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
3253                         if let Some(vout) = htlc.0.transaction_output_index {
3254                                 let preimage = if !htlc.0.offered {
3255                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
3256                                                 // We can't build an HTLC-Success transaction without the preimage
3257                                                 continue;
3258                                         }
3259                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
3260                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
3261                                         // current locktime requirements on-chain. We will broadcast them in
3262                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
3263                                         // Note that we add + 1 as transactions are broadcastable when they can be
3264                                         // confirmed in the next block.
3265                                         continue;
3266                                 } else { None };
3267                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
3268                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
3269                                         holder_transactions.push(htlc_tx);
3270                                 }
3271                         }
3272                 }
3273                 // 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.
3274                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
3275                 holder_transactions
3276         }
3277
3278         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
3279         /// Note that this includes possibly-locktimed-in-the-future transactions!
3280         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
3281                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
3282                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
3283                 let txid = commitment_tx.txid();
3284                 let mut holder_transactions = vec![commitment_tx];
3285                 // When anchor outputs are present, the HTLC transactions are only final once the commitment
3286                 // transaction confirms due to the CSV 1 encumberance.
3287                 if self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
3288                         return holder_transactions;
3289                 }
3290                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
3291                         if let Some(vout) = htlc.0.transaction_output_index {
3292                                 let preimage = if !htlc.0.offered {
3293                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
3294                                                 // We can't build an HTLC-Success transaction without the preimage
3295                                                 continue;
3296                                         }
3297                                 } else { None };
3298                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
3299                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
3300                                         holder_transactions.push(htlc_tx);
3301                                 }
3302                         }
3303                 }
3304                 holder_transactions
3305         }
3306
3307         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>
3308                 where B::Target: BroadcasterInterface,
3309                       F::Target: FeeEstimator,
3310                                         L::Target: Logger,
3311         {
3312                 let block_hash = header.block_hash();
3313                 self.best_block = BestBlock::new(block_hash, height);
3314
3315                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3316                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
3317         }
3318
3319         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
3320                 &mut self,
3321                 header: &BlockHeader,
3322                 height: u32,
3323                 broadcaster: B,
3324                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3325                 logger: L,
3326         ) -> Vec<TransactionOutputs>
3327         where
3328                 B::Target: BroadcasterInterface,
3329                 F::Target: FeeEstimator,
3330                 L::Target: Logger,
3331         {
3332                 let block_hash = header.block_hash();
3333
3334                 if height > self.best_block.height() {
3335                         self.best_block = BestBlock::new(block_hash, height);
3336                         self.block_confirmed(height, block_hash, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
3337                 } else if block_hash != self.best_block.block_hash() {
3338                         self.best_block = BestBlock::new(block_hash, height);
3339                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
3340                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
3341                         Vec::new()
3342                 } else { Vec::new() }
3343         }
3344
3345         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
3346                 &mut self,
3347                 header: &BlockHeader,
3348                 txdata: &TransactionData,
3349                 height: u32,
3350                 broadcaster: B,
3351                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3352                 logger: L,
3353         ) -> Vec<TransactionOutputs>
3354         where
3355                 B::Target: BroadcasterInterface,
3356                 F::Target: FeeEstimator,
3357                 L::Target: Logger,
3358         {
3359                 let txn_matched = self.filter_block(txdata);
3360                 for tx in &txn_matched {
3361                         let mut output_val = 0;
3362                         for out in tx.output.iter() {
3363                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
3364                                 output_val += out.value;
3365                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
3366                         }
3367                 }
3368
3369                 let block_hash = header.block_hash();
3370
3371                 let mut watch_outputs = Vec::new();
3372                 let mut claimable_outpoints = Vec::new();
3373                 'tx_iter: for tx in &txn_matched {
3374                         let txid = tx.txid();
3375                         // If a transaction has already been confirmed, ensure we don't bother processing it duplicatively.
3376                         if Some(txid) == self.funding_spend_confirmed {
3377                                 log_debug!(logger, "Skipping redundant processing of funding-spend tx {} as it was previously confirmed", txid);
3378                                 continue 'tx_iter;
3379                         }
3380                         for ev in self.onchain_events_awaiting_threshold_conf.iter() {
3381                                 if ev.txid == txid {
3382                                         if let Some(conf_hash) = ev.block_hash {
3383                                                 assert_eq!(header.block_hash(), conf_hash,
3384                                                         "Transaction {} was already confirmed and is being re-confirmed in a different block.\n\
3385                                                         This indicates a severe bug in the transaction connection logic - a reorg should have been processed first!", ev.txid);
3386                                         }
3387                                         log_debug!(logger, "Skipping redundant processing of confirming tx {} as it was previously confirmed", txid);
3388                                         continue 'tx_iter;
3389                                 }
3390                         }
3391                         for htlc in self.htlcs_resolved_on_chain.iter() {
3392                                 if Some(txid) == htlc.resolving_txid {
3393                                         log_debug!(logger, "Skipping redundant processing of HTLC resolution tx {} as it was previously confirmed", txid);
3394                                         continue 'tx_iter;
3395                                 }
3396                         }
3397                         for spendable_txid in self.spendable_txids_confirmed.iter() {
3398                                 if txid == *spendable_txid {
3399                                         log_debug!(logger, "Skipping redundant processing of spendable tx {} as it was previously confirmed", txid);
3400                                         continue 'tx_iter;
3401                                 }
3402                         }
3403
3404                         if tx.input.len() == 1 {
3405                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
3406                                 // commitment transactions and HTLC transactions will all only ever have one input
3407                                 // (except for HTLC transactions for channels with anchor outputs), which is an easy
3408                                 // way to filter out any potential non-matching txn for lazy filters.
3409                                 let prevout = &tx.input[0].previous_output;
3410                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
3411                                         let mut balance_spendable_csv = None;
3412                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
3413                                                 &self.funding_info.0.to_channel_id(), txid);
3414                                         self.funding_spend_seen = true;
3415                                         let mut commitment_tx_to_counterparty_output = None;
3416                                         if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.0 >> 8*3) as u8 == 0x20 {
3417                                                 let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
3418                                                         self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
3419                                                 commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
3420                                                 if !new_outputs.1.is_empty() {
3421                                                         watch_outputs.push(new_outputs);
3422                                                 }
3423                                                 claimable_outpoints.append(&mut new_outpoints);
3424                                                 if new_outpoints.is_empty() {
3425                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
3426                                                                 debug_assert!(commitment_tx_to_counterparty_output.is_none(),
3427                                                                         "A commitment transaction matched as both a counterparty and local commitment tx?");
3428                                                                 if !new_outputs.1.is_empty() {
3429                                                                         watch_outputs.push(new_outputs);
3430                                                                 }
3431                                                                 claimable_outpoints.append(&mut new_outpoints);
3432                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
3433                                                         }
3434                                                 }
3435                                         }
3436                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3437                                                 txid,
3438                                                 transaction: Some((*tx).clone()),
3439                                                 height,
3440                                                 block_hash: Some(block_hash),
3441                                                 event: OnchainEvent::FundingSpendConfirmation {
3442                                                         on_local_output_csv: balance_spendable_csv,
3443                                                         commitment_tx_to_counterparty_output,
3444                                                 },
3445                                         });
3446                                 }
3447                         }
3448                         if tx.input.len() >= 1 {
3449                                 // While all commitment transactions have one input, HTLC transactions may have more
3450                                 // if the HTLC was present in an anchor channel. HTLCs can also be resolved in a few
3451                                 // other ways which can have more than one output.
3452                                 for tx_input in &tx.input {
3453                                         let commitment_txid = tx_input.previous_output.txid;
3454                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&commitment_txid) {
3455                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(
3456                                                         &tx, commitment_number, &commitment_txid, height, &logger
3457                                                 );
3458                                                 claimable_outpoints.append(&mut new_outpoints);
3459                                                 if let Some(new_outputs) = new_outputs_option {
3460                                                         watch_outputs.push(new_outputs);
3461                                                 }
3462                                                 // Since there may be multiple HTLCs for this channel (all spending the
3463                                                 // same commitment tx) being claimed by the counterparty within the same
3464                                                 // transaction, and `check_spend_counterparty_htlc` already checks all the
3465                                                 // ones relevant to this channel, we can safely break from our loop.
3466                                                 break;
3467                                         }
3468                                 }
3469                                 self.is_resolving_htlc_output(&tx, height, &block_hash, &logger);
3470
3471                                 self.check_tx_and_push_spendable_outputs(&tx, height, &block_hash, &logger);
3472                         }
3473                 }
3474
3475                 if height > self.best_block.height() {
3476                         self.best_block = BestBlock::new(block_hash, height);
3477                 }
3478
3479                 self.block_confirmed(height, block_hash, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
3480         }
3481
3482         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
3483         /// `self.best_block` before calling if a new best blockchain tip is available. More
3484         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
3485         /// complexity especially in
3486         /// `OnchainTx::update_claims_view_from_requests`/`OnchainTx::update_claims_view_from_matched_txn`.
3487         ///
3488         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
3489         /// confirmed at, even if it is not the current best height.
3490         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
3491                 &mut self,
3492                 conf_height: u32,
3493                 conf_hash: BlockHash,
3494                 txn_matched: Vec<&Transaction>,
3495                 mut watch_outputs: Vec<TransactionOutputs>,
3496                 mut claimable_outpoints: Vec<PackageTemplate>,
3497                 broadcaster: &B,
3498                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3499                 logger: &L,
3500         ) -> Vec<TransactionOutputs>
3501         where
3502                 B::Target: BroadcasterInterface,
3503                 F::Target: FeeEstimator,
3504                 L::Target: Logger,
3505         {
3506                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
3507                 debug_assert!(self.best_block.height() >= conf_height);
3508
3509                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
3510                 if should_broadcast {
3511                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone(), self.channel_value_satoshis, self.onchain_tx_handler.channel_type_features().clone());
3512                         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());
3513                         claimable_outpoints.push(commitment_package);
3514                         self.pending_monitor_events.push(MonitorEvent::HolderForceClosed(self.funding_info.0));
3515                         // Although we aren't signing the transaction directly here, the transaction will be signed
3516                         // in the claim that is queued to OnchainTxHandler. We set holder_tx_signed here to reject
3517                         // new channel updates.
3518                         self.holder_tx_signed = true;
3519                         // We can't broadcast our HTLC transactions while the commitment transaction is
3520                         // unconfirmed. We'll delay doing so until we detect the confirmed commitment in
3521                         // `transactions_confirmed`.
3522                         if !self.onchain_tx_handler.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
3523                                 // Because we're broadcasting a commitment transaction, we should construct the package
3524                                 // assuming it gets confirmed in the next block. Sadly, we have code which considers
3525                                 // "not yet confirmed" things as discardable, so we cannot do that here.
3526                                 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
3527                                 let unsigned_commitment_tx = self.onchain_tx_handler.get_unsigned_holder_commitment_tx();
3528                                 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &unsigned_commitment_tx);
3529                                 if !new_outputs.is_empty() {
3530                                         watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
3531                                 }
3532                                 claimable_outpoints.append(&mut new_outpoints);
3533                         }
3534                 }
3535
3536                 // Find which on-chain events have reached their confirmation threshold.
3537                 let onchain_events_awaiting_threshold_conf =
3538                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
3539                 let mut onchain_events_reaching_threshold_conf = Vec::new();
3540                 for entry in onchain_events_awaiting_threshold_conf {
3541                         if entry.has_reached_confirmation_threshold(&self.best_block) {
3542                                 onchain_events_reaching_threshold_conf.push(entry);
3543                         } else {
3544                                 self.onchain_events_awaiting_threshold_conf.push(entry);
3545                         }
3546                 }
3547
3548                 // Used to check for duplicate HTLC resolutions.
3549                 #[cfg(debug_assertions)]
3550                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
3551                         .iter()
3552                         .filter_map(|entry| match &entry.event {
3553                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
3554                                 _ => None,
3555                         })
3556                         .collect();
3557                 #[cfg(debug_assertions)]
3558                 let mut matured_htlcs = Vec::new();
3559
3560                 // Produce actionable events from on-chain events having reached their threshold.
3561                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
3562                         match entry.event {
3563                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
3564                                         // Check for duplicate HTLC resolutions.
3565                                         #[cfg(debug_assertions)]
3566                                         {
3567                                                 debug_assert!(
3568                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
3569                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
3570                                                          call either transaction_unconfirmed for the conflicting transaction \
3571                                                          or block_disconnected for a block containing it.");
3572                                                 debug_assert!(
3573                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
3574                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
3575                                                          call either transaction_unconfirmed for the conflicting transaction \
3576                                                          or block_disconnected for a block containing it.");
3577                                                 matured_htlcs.push(source.clone());
3578                                         }
3579
3580                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
3581                                                 &payment_hash, entry.txid);
3582                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3583                                                 payment_hash,
3584                                                 payment_preimage: None,
3585                                                 source: source.clone(),
3586                                                 htlc_value_satoshis,
3587                                         }));
3588                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3589                                                 commitment_tx_output_idx,
3590                                                 resolving_txid: Some(entry.txid),
3591                                                 resolving_tx: entry.transaction,
3592                                                 payment_preimage: None,
3593                                         });
3594                                 },
3595                                 OnchainEvent::MaturingOutput { descriptor } => {
3596                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
3597                                         self.pending_events.push(Event::SpendableOutputs {
3598                                                 outputs: vec![descriptor],
3599                                                 channel_id: Some(self.funding_info.0.to_channel_id()),
3600                                         });
3601                                         self.spendable_txids_confirmed.push(entry.txid);
3602                                 },
3603                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
3604                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
3605                                                 commitment_tx_output_idx: Some(commitment_tx_output_idx),
3606                                                 resolving_txid: Some(entry.txid),
3607                                                 resolving_tx: entry.transaction,
3608                                                 payment_preimage: preimage,
3609                                         });
3610                                 },
3611                                 OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
3612                                         self.funding_spend_confirmed = Some(entry.txid);
3613                                         self.confirmed_commitment_tx_counterparty_output = commitment_tx_to_counterparty_output;
3614                                 },
3615                         }
3616                 }
3617
3618                 self.onchain_tx_handler.update_claims_view_from_requests(claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
3619                 self.onchain_tx_handler.update_claims_view_from_matched_txn(&txn_matched, conf_height, conf_hash, self.best_block.height(), broadcaster, fee_estimator, logger);
3620
3621                 // Determine new outputs to watch by comparing against previously known outputs to watch,
3622                 // updating the latter in the process.
3623                 watch_outputs.retain(|&(ref txid, ref txouts)| {
3624                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
3625                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
3626                 });
3627                 #[cfg(test)]
3628                 {
3629                         // If we see a transaction for which we registered outputs previously,
3630                         // make sure the registered scriptpubkey at the expected index match
3631                         // the actual transaction output one. We failed this case before #653.
3632                         for tx in &txn_matched {
3633                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
3634                                         for idx_and_script in outputs.iter() {
3635                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
3636                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
3637                                         }
3638                                 }
3639                         }
3640                 }
3641                 watch_outputs
3642         }
3643
3644         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
3645                 where B::Target: BroadcasterInterface,
3646                       F::Target: FeeEstimator,
3647                       L::Target: Logger,
3648         {
3649                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
3650
3651                 //We may discard:
3652                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
3653                 //- maturing spendable output has transaction paying us has been disconnected
3654                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
3655
3656                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
3657                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
3658
3659                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
3660         }
3661
3662         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
3663                 &mut self,
3664                 txid: &Txid,
3665                 broadcaster: B,
3666                 fee_estimator: &LowerBoundedFeeEstimator<F>,
3667                 logger: L,
3668         ) where
3669                 B::Target: BroadcasterInterface,
3670                 F::Target: FeeEstimator,
3671                 L::Target: Logger,
3672         {
3673                 let mut removed_height = None;
3674                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
3675                         if entry.txid == *txid {
3676                                 removed_height = Some(entry.height);
3677                                 break;
3678                         }
3679                 }
3680
3681                 if let Some(removed_height) = removed_height {
3682                         log_info!(logger, "transaction_unconfirmed of txid {} implies height {} was reorg'd out", txid, removed_height);
3683                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.height >= removed_height {
3684                                 log_info!(logger, "Transaction {} reorg'd out", entry.txid);
3685                                 false
3686                         } else { true });
3687                 }
3688
3689                 debug_assert!(!self.onchain_events_awaiting_threshold_conf.iter().any(|ref entry| entry.txid == *txid));
3690
3691                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
3692         }
3693
3694         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
3695         /// transactions thereof.
3696         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
3697                 let mut matched_txn = HashSet::new();
3698                 txdata.iter().filter(|&&(_, tx)| {
3699                         let mut matches = self.spends_watched_output(tx);
3700                         for input in tx.input.iter() {
3701                                 if matches { break; }
3702                                 if matched_txn.contains(&input.previous_output.txid) {
3703                                         matches = true;
3704                                 }
3705                         }
3706                         if matches {
3707                                 matched_txn.insert(tx.txid());
3708                         }
3709                         matches
3710                 }).map(|(_, tx)| *tx).collect()
3711         }
3712
3713         /// Checks if a given transaction spends any watched outputs.
3714         fn spends_watched_output(&self, tx: &Transaction) -> bool {
3715                 for input in tx.input.iter() {
3716                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
3717                                 for (idx, _script_pubkey) in outputs.iter() {
3718                                         if *idx == input.previous_output.vout {
3719                                                 #[cfg(test)]
3720                                                 {
3721                                                         // If the expected script is a known type, check that the witness
3722                                                         // appears to be spending the correct type (ie that the match would
3723                                                         // actually succeed in BIP 158/159-style filters).
3724                                                         if _script_pubkey.is_v0_p2wsh() {
3725                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
3726                                                                         // In at least one test we use a deliberately bogus witness
3727                                                                         // script which hit an old panic. Thus, we check for that here
3728                                                                         // and avoid the assert if its the expected bogus script.
3729                                                                         return true;
3730                                                                 }
3731
3732                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
3733                                                         } else if _script_pubkey.is_v0_p2wpkh() {
3734                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
3735                                                         } else { panic!(); }
3736                                                 }
3737                                                 return true;
3738                                         }
3739                                 }
3740                         }
3741                 }
3742
3743                 false
3744         }
3745
3746         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
3747                 // There's no need to broadcast our commitment transaction if we've seen one confirmed (even
3748                 // with 1 confirmation) as it'll be rejected as duplicate/conflicting.
3749                 if self.funding_spend_confirmed.is_some() ||
3750                         self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
3751                                 OnchainEvent::FundingSpendConfirmation { .. } => true,
3752                                 _ => false,
3753                         }).is_some()
3754                 {
3755                         return false;
3756                 }
3757                 // We need to consider all HTLCs which are:
3758                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
3759                 //    transactions and we'd end up in a race, or
3760                 //  * are in our latest holder commitment transaction, as this is the thing we will
3761                 //    broadcast if we go on-chain.
3762                 // Note that we consider HTLCs which were below dust threshold here - while they don't
3763                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
3764                 // to the source, and if we don't fail the channel we will have to ensure that the next
3765                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
3766                 // easier to just fail the channel as this case should be rare enough anyway.
3767                 let height = self.best_block.height();
3768                 macro_rules! scan_commitment {
3769                         ($htlcs: expr, $holder_tx: expr) => {
3770                                 for ref htlc in $htlcs {
3771                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
3772                                         // chain with enough room to claim the HTLC without our counterparty being able to
3773                                         // time out the HTLC first.
3774                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
3775                                         // concern is being able to claim the corresponding inbound HTLC (on another
3776                                         // channel) before it expires. In fact, we don't even really care if our
3777                                         // counterparty here claims such an outbound HTLC after it expired as long as we
3778                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
3779                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
3780                                         // we give ourselves a few blocks of headroom after expiration before going
3781                                         // on-chain for an expired HTLC.
3782                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
3783                                         // from us until we've reached the point where we go on-chain with the
3784                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
3785                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
3786                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
3787                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
3788                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
3789                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
3790                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
3791                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
3792                                         //  The final, above, condition is checked for statically in channelmanager
3793                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
3794                                         let htlc_outbound = $holder_tx == htlc.offered;
3795                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
3796                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
3797                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
3798                                                 return true;
3799                                         }
3800                                 }
3801                         }
3802                 }
3803
3804                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
3805
3806                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
3807                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3808                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3809                         }
3810                 }
3811                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
3812                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
3813                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
3814                         }
3815                 }
3816
3817                 false
3818         }
3819
3820         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
3821         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
3822         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L) where L::Target: Logger {
3823                 'outer_loop: for input in &tx.input {
3824                         let mut payment_data = None;
3825                         let htlc_claim = HTLCClaim::from_witness(&input.witness);
3826                         let revocation_sig_claim = htlc_claim == Some(HTLCClaim::Revocation);
3827                         let accepted_preimage_claim = htlc_claim == Some(HTLCClaim::AcceptedPreimage);
3828                         #[cfg(not(fuzzing))]
3829                         let accepted_timeout_claim = htlc_claim == Some(HTLCClaim::AcceptedTimeout);
3830                         let offered_preimage_claim = htlc_claim == Some(HTLCClaim::OfferedPreimage);
3831                         #[cfg(not(fuzzing))]
3832                         let offered_timeout_claim = htlc_claim == Some(HTLCClaim::OfferedTimeout);
3833
3834                         let mut payment_preimage = PaymentPreimage([0; 32]);
3835                         if offered_preimage_claim || accepted_preimage_claim {
3836                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
3837                         }
3838
3839                         macro_rules! log_claim {
3840                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
3841                                         let outbound_htlc = $holder_tx == $htlc.offered;
3842                                         // HTLCs must either be claimed by a matching script type or through the
3843                                         // revocation path:
3844                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3845                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
3846                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3847                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
3848                                         // Further, only exactly one of the possible spend paths should have been
3849                                         // matched by any HTLC spend:
3850                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
3851                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
3852                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
3853                                                          revocation_sig_claim as u8, 1);
3854                                         if ($holder_tx && revocation_sig_claim) ||
3855                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
3856                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
3857                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3858                                                         if outbound_htlc { "outbound" } else { "inbound" }, &$htlc.payment_hash,
3859                                                         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" });
3860                                         } else {
3861                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
3862                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
3863                                                         if outbound_htlc { "outbound" } else { "inbound" }, &$htlc.payment_hash,
3864                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
3865                                         }
3866                                 }
3867                         }
3868
3869                         macro_rules! check_htlc_valid_counterparty {
3870                                 ($counterparty_txid: expr, $htlc_output: expr) => {
3871                                         if let Some(txid) = $counterparty_txid {
3872                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
3873                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
3874                                                                 if let &Some(ref source) = pending_source {
3875                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
3876                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
3877                                                                         break;
3878                                                                 }
3879                                                         }
3880                                                 }
3881                                         }
3882                                 }
3883                         }
3884
3885                         macro_rules! scan_commitment {
3886                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
3887                                         for (ref htlc_output, source_option) in $htlcs {
3888                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
3889                                                         if let Some(ref source) = source_option {
3890                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
3891                                                                 // We have a resolution of an HTLC either from one of our latest
3892                                                                 // holder commitment transactions or an unrevoked counterparty commitment
3893                                                                 // transaction. This implies we either learned a preimage, the HTLC
3894                                                                 // has timed out, or we screwed up. In any case, we should now
3895                                                                 // resolve the source HTLC with the original sender.
3896                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
3897                                                         } else if !$holder_tx {
3898                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
3899                                                                 if payment_data.is_none() {
3900                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
3901                                                                 }
3902                                                         }
3903                                                         if payment_data.is_none() {
3904                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
3905                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
3906                                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3907                                                                         txid: tx.txid(), height, block_hash: Some(*block_hash), transaction: Some(tx.clone()),
3908                                                                         event: OnchainEvent::HTLCSpendConfirmation {
3909                                                                                 commitment_tx_output_idx: input.previous_output.vout,
3910                                                                                 preimage: if accepted_preimage_claim || offered_preimage_claim {
3911                                                                                         Some(payment_preimage) } else { None },
3912                                                                                 // If this is a payment to us (ie !outbound_htlc), wait for
3913                                                                                 // the CSV delay before dropping the HTLC from claimable
3914                                                                                 // balance if the claim was an HTLC-Success transaction (ie
3915                                                                                 // accepted_preimage_claim).
3916                                                                                 on_to_local_output_csv: if accepted_preimage_claim && !outbound_htlc {
3917                                                                                         Some(self.on_holder_tx_csv) } else { None },
3918                                                                         },
3919                                                                 });
3920                                                                 continue 'outer_loop;
3921                                                         }
3922                                                 }
3923                                         }
3924                                 }
3925                         }
3926
3927                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
3928                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3929                                         "our latest holder commitment tx", true);
3930                         }
3931                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
3932                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
3933                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
3934                                                 "our previous holder commitment tx", true);
3935                                 }
3936                         }
3937                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
3938                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
3939                                         "counterparty commitment tx", false);
3940                         }
3941
3942                         // Check that scan_commitment, above, decided there is some source worth relaying an
3943                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
3944                         if let Some((source, payment_hash, amount_msat)) = payment_data {
3945                                 if accepted_preimage_claim {
3946                                         if !self.pending_monitor_events.iter().any(
3947                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
3948                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3949                                                         txid: tx.txid(),
3950                                                         height,
3951                                                         block_hash: Some(*block_hash),
3952                                                         transaction: Some(tx.clone()),
3953                                                         event: OnchainEvent::HTLCSpendConfirmation {
3954                                                                 commitment_tx_output_idx: input.previous_output.vout,
3955                                                                 preimage: Some(payment_preimage),
3956                                                                 on_to_local_output_csv: None,
3957                                                         },
3958                                                 });
3959                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3960                                                         source,
3961                                                         payment_preimage: Some(payment_preimage),
3962                                                         payment_hash,
3963                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3964                                                 }));
3965                                         }
3966                                 } else if offered_preimage_claim {
3967                                         if !self.pending_monitor_events.iter().any(
3968                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
3969                                                         upd.source == source
3970                                                 } else { false }) {
3971                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
3972                                                         txid: tx.txid(),
3973                                                         transaction: Some(tx.clone()),
3974                                                         height,
3975                                                         block_hash: Some(*block_hash),
3976                                                         event: OnchainEvent::HTLCSpendConfirmation {
3977                                                                 commitment_tx_output_idx: input.previous_output.vout,
3978                                                                 preimage: Some(payment_preimage),
3979                                                                 on_to_local_output_csv: None,
3980                                                         },
3981                                                 });
3982                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3983                                                         source,
3984                                                         payment_preimage: Some(payment_preimage),
3985                                                         payment_hash,
3986                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3987                                                 }));
3988                                         }
3989                                 } else {
3990                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3991                                                 if entry.height != height { return true; }
3992                                                 match entry.event {
3993                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3994                                                                 *htlc_source != source
3995                                                         },
3996                                                         _ => true,
3997                                                 }
3998                                         });
3999                                         let entry = OnchainEventEntry {
4000                                                 txid: tx.txid(),
4001                                                 transaction: Some(tx.clone()),
4002                                                 height,
4003                                                 block_hash: Some(*block_hash),
4004                                                 event: OnchainEvent::HTLCUpdate {
4005                                                         source, payment_hash,
4006                                                         htlc_value_satoshis: Some(amount_msat / 1000),
4007                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
4008                                                 },
4009                                         };
4010                                         log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", &payment_hash, entry.confirmation_threshold());
4011                                         self.onchain_events_awaiting_threshold_conf.push(entry);
4012                                 }
4013                         }
4014                 }
4015         }
4016
4017         fn get_spendable_outputs(&self, tx: &Transaction) -> Vec<SpendableOutputDescriptor> {
4018                 let mut spendable_outputs = Vec::new();
4019                 for (i, outp) in tx.output.iter().enumerate() {
4020                         if outp.script_pubkey == self.destination_script {
4021                                 spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
4022                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
4023                                         output: outp.clone(),
4024                                 });
4025                         }
4026                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
4027                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
4028                                         spendable_outputs.push(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
4029                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
4030                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
4031                                                 to_self_delay: self.on_holder_tx_csv,
4032                                                 output: outp.clone(),
4033                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
4034                                                 channel_keys_id: self.channel_keys_id,
4035                                                 channel_value_satoshis: self.channel_value_satoshis,
4036                                         }));
4037                                 }
4038                         }
4039                         if self.counterparty_payment_script == outp.script_pubkey {
4040                                 spendable_outputs.push(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
4041                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
4042                                         output: outp.clone(),
4043                                         channel_keys_id: self.channel_keys_id,
4044                                         channel_value_satoshis: self.channel_value_satoshis,
4045                                 }));
4046                         }
4047                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
4048                                 spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
4049                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
4050                                         output: outp.clone(),
4051                                 });
4052                         }
4053                 }
4054                 spendable_outputs
4055         }
4056
4057         /// Checks if the confirmed transaction is paying funds back to some address we can assume to
4058         /// own.
4059         fn check_tx_and_push_spendable_outputs<L: Deref>(
4060                 &mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L,
4061         ) where L::Target: Logger {
4062                 for spendable_output in self.get_spendable_outputs(tx) {
4063                         let entry = OnchainEventEntry {
4064                                 txid: tx.txid(),
4065                                 transaction: Some(tx.clone()),
4066                                 height,
4067                                 block_hash: Some(*block_hash),
4068                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
4069                         };
4070                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
4071                         self.onchain_events_awaiting_threshold_conf.push(entry);
4072                 }
4073         }
4074 }
4075
4076 impl<Signer: WriteableEcdsaChannelSigner, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
4077 where
4078         T::Target: BroadcasterInterface,
4079         F::Target: FeeEstimator,
4080         L::Target: Logger,
4081 {
4082         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
4083                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
4084         }
4085
4086         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
4087                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
4088         }
4089 }
4090
4091 impl<Signer: WriteableEcdsaChannelSigner, M, T: Deref, F: Deref, L: Deref> chain::Confirm for (M, T, F, L)
4092 where
4093         M: Deref<Target = ChannelMonitor<Signer>>,
4094         T::Target: BroadcasterInterface,
4095         F::Target: FeeEstimator,
4096         L::Target: Logger,
4097 {
4098         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
4099                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
4100         }
4101
4102         fn transaction_unconfirmed(&self, txid: &Txid) {
4103                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
4104         }
4105
4106         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
4107                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
4108         }
4109
4110         fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
4111                 self.0.get_relevant_txids()
4112         }
4113 }
4114
4115 const MAX_ALLOC_SIZE: usize = 64*1024;
4116
4117 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP)>
4118                 for (BlockHash, ChannelMonitor<SP::Signer>) {
4119         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP)) -> Result<Self, DecodeError> {
4120                 macro_rules! unwrap_obj {
4121                         ($key: expr) => {
4122                                 match $key {
4123                                         Ok(res) => res,
4124                                         Err(_) => return Err(DecodeError::InvalidValue),
4125                                 }
4126                         }
4127                 }
4128
4129                 let (entropy_source, signer_provider) = args;
4130
4131                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
4132
4133                 let latest_update_id: u64 = Readable::read(reader)?;
4134                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
4135
4136                 let destination_script = Readable::read(reader)?;
4137                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
4138                         0 => {
4139                                 let revokable_address = Readable::read(reader)?;
4140                                 let per_commitment_point = Readable::read(reader)?;
4141                                 let revokable_script = Readable::read(reader)?;
4142                                 Some((revokable_address, per_commitment_point, revokable_script))
4143                         },
4144                         1 => { None },
4145                         _ => return Err(DecodeError::InvalidValue),
4146                 };
4147                 let counterparty_payment_script = Readable::read(reader)?;
4148                 let shutdown_script = {
4149                         let script = <Script as Readable>::read(reader)?;
4150                         if script.is_empty() { None } else { Some(script) }
4151                 };
4152
4153                 let channel_keys_id = Readable::read(reader)?;
4154                 let holder_revocation_basepoint = Readable::read(reader)?;
4155                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
4156                 // barely-init'd ChannelMonitors that we can't do anything with.
4157                 let outpoint = OutPoint {
4158                         txid: Readable::read(reader)?,
4159                         index: Readable::read(reader)?,
4160                 };
4161                 let funding_info = (outpoint, Readable::read(reader)?);
4162                 let current_counterparty_commitment_txid = Readable::read(reader)?;
4163                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
4164
4165                 let counterparty_commitment_params = Readable::read(reader)?;
4166                 let funding_redeemscript = Readable::read(reader)?;
4167                 let channel_value_satoshis = Readable::read(reader)?;
4168
4169                 let their_cur_per_commitment_points = {
4170                         let first_idx = <U48 as Readable>::read(reader)?.0;
4171                         if first_idx == 0 {
4172                                 None
4173                         } else {
4174                                 let first_point = Readable::read(reader)?;
4175                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
4176                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
4177                                         Some((first_idx, first_point, None))
4178                                 } else {
4179                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
4180                                 }
4181                         }
4182                 };
4183
4184                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
4185
4186                 let commitment_secrets = Readable::read(reader)?;
4187
4188                 macro_rules! read_htlc_in_commitment {
4189                         () => {
4190                                 {
4191                                         let offered: bool = Readable::read(reader)?;
4192                                         let amount_msat: u64 = Readable::read(reader)?;
4193                                         let cltv_expiry: u32 = Readable::read(reader)?;
4194                                         let payment_hash: PaymentHash = Readable::read(reader)?;
4195                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
4196
4197                                         HTLCOutputInCommitment {
4198                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
4199                                         }
4200                                 }
4201                         }
4202                 }
4203
4204                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
4205                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
4206                 for _ in 0..counterparty_claimable_outpoints_len {
4207                         let txid: Txid = Readable::read(reader)?;
4208                         let htlcs_count: u64 = Readable::read(reader)?;
4209                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
4210                         for _ in 0..htlcs_count {
4211                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
4212                         }
4213                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
4214                                 return Err(DecodeError::InvalidValue);
4215                         }
4216                 }
4217
4218                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
4219                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
4220                 for _ in 0..counterparty_commitment_txn_on_chain_len {
4221                         let txid: Txid = Readable::read(reader)?;
4222                         let commitment_number = <U48 as Readable>::read(reader)?.0;
4223                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
4224                                 return Err(DecodeError::InvalidValue);
4225                         }
4226                 }
4227
4228                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
4229                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
4230                 for _ in 0..counterparty_hash_commitment_number_len {
4231                         let payment_hash: PaymentHash = Readable::read(reader)?;
4232                         let commitment_number = <U48 as Readable>::read(reader)?.0;
4233                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
4234                                 return Err(DecodeError::InvalidValue);
4235                         }
4236                 }
4237
4238                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
4239                         match <u8 as Readable>::read(reader)? {
4240                                 0 => None,
4241                                 1 => {
4242                                         Some(Readable::read(reader)?)
4243                                 },
4244                                 _ => return Err(DecodeError::InvalidValue),
4245                         };
4246                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
4247
4248                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
4249                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
4250
4251                 let payment_preimages_len: u64 = Readable::read(reader)?;
4252                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
4253                 for _ in 0..payment_preimages_len {
4254                         let preimage: PaymentPreimage = Readable::read(reader)?;
4255                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4256                         if let Some(_) = payment_preimages.insert(hash, preimage) {
4257                                 return Err(DecodeError::InvalidValue);
4258                         }
4259                 }
4260
4261                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
4262                 let mut pending_monitor_events = Some(
4263                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
4264                 for _ in 0..pending_monitor_events_len {
4265                         let ev = match <u8 as Readable>::read(reader)? {
4266                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
4267                                 1 => MonitorEvent::HolderForceClosed(funding_info.0),
4268                                 _ => return Err(DecodeError::InvalidValue)
4269                         };
4270                         pending_monitor_events.as_mut().unwrap().push(ev);
4271                 }
4272
4273                 let pending_events_len: u64 = Readable::read(reader)?;
4274                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
4275                 for _ in 0..pending_events_len {
4276                         if let Some(event) = MaybeReadable::read(reader)? {
4277                                 pending_events.push(event);
4278                         }
4279                 }
4280
4281                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
4282
4283                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
4284                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
4285                 for _ in 0..waiting_threshold_conf_len {
4286                         if let Some(val) = MaybeReadable::read(reader)? {
4287                                 onchain_events_awaiting_threshold_conf.push(val);
4288                         }
4289                 }
4290
4291                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
4292                 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>>())));
4293                 for _ in 0..outputs_to_watch_len {
4294                         let txid = Readable::read(reader)?;
4295                         let outputs_len: u64 = Readable::read(reader)?;
4296                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
4297                         for _ in 0..outputs_len {
4298                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
4299                         }
4300                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
4301                                 return Err(DecodeError::InvalidValue);
4302                         }
4303                 }
4304                 let onchain_tx_handler: OnchainTxHandler<SP::Signer> = ReadableArgs::read(
4305                         reader, (entropy_source, signer_provider, channel_value_satoshis, channel_keys_id)
4306                 )?;
4307
4308                 let lockdown_from_offchain = Readable::read(reader)?;
4309                 let holder_tx_signed = Readable::read(reader)?;
4310
4311                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
4312                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
4313                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
4314                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
4315                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
4316                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
4317                                 return Err(DecodeError::InvalidValue);
4318                         }
4319                 }
4320
4321                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
4322                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
4323                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
4324                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
4325                         return Err(DecodeError::InvalidValue);
4326                 }
4327
4328                 let mut funding_spend_confirmed = None;
4329                 let mut htlcs_resolved_on_chain = Some(Vec::new());
4330                 let mut funding_spend_seen = Some(false);
4331                 let mut counterparty_node_id = None;
4332                 let mut confirmed_commitment_tx_counterparty_output = None;
4333                 let mut spendable_txids_confirmed = Some(Vec::new());
4334                 let mut counterparty_fulfilled_htlcs = Some(HashMap::new());
4335                 let mut initial_counterparty_commitment_info = None;
4336                 read_tlv_fields!(reader, {
4337                         (1, funding_spend_confirmed, option),
4338                         (3, htlcs_resolved_on_chain, optional_vec),
4339                         (5, pending_monitor_events, optional_vec),
4340                         (7, funding_spend_seen, option),
4341                         (9, counterparty_node_id, option),
4342                         (11, confirmed_commitment_tx_counterparty_output, option),
4343                         (13, spendable_txids_confirmed, optional_vec),
4344                         (15, counterparty_fulfilled_htlcs, option),
4345                         (17, initial_counterparty_commitment_info, option),
4346                 });
4347
4348                 Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
4349                         latest_update_id,
4350                         commitment_transaction_number_obscure_factor,
4351
4352                         destination_script,
4353                         broadcasted_holder_revokable_script,
4354                         counterparty_payment_script,
4355                         shutdown_script,
4356
4357                         channel_keys_id,
4358                         holder_revocation_basepoint,
4359                         funding_info,
4360                         current_counterparty_commitment_txid,
4361                         prev_counterparty_commitment_txid,
4362
4363                         counterparty_commitment_params,
4364                         funding_redeemscript,
4365                         channel_value_satoshis,
4366                         their_cur_per_commitment_points,
4367
4368                         on_holder_tx_csv,
4369
4370                         commitment_secrets,
4371                         counterparty_claimable_outpoints,
4372                         counterparty_commitment_txn_on_chain,
4373                         counterparty_hash_commitment_number,
4374                         counterparty_fulfilled_htlcs: counterparty_fulfilled_htlcs.unwrap(),
4375
4376                         prev_holder_signed_commitment_tx,
4377                         current_holder_commitment_tx,
4378                         current_counterparty_commitment_number,
4379                         current_holder_commitment_number,
4380
4381                         payment_preimages,
4382                         pending_monitor_events: pending_monitor_events.unwrap(),
4383                         pending_events,
4384                         is_processing_pending_events: false,
4385
4386                         onchain_events_awaiting_threshold_conf,
4387                         outputs_to_watch,
4388
4389                         onchain_tx_handler,
4390
4391                         lockdown_from_offchain,
4392                         holder_tx_signed,
4393                         funding_spend_seen: funding_spend_seen.unwrap(),
4394                         funding_spend_confirmed,
4395                         confirmed_commitment_tx_counterparty_output,
4396                         htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
4397                         spendable_txids_confirmed: spendable_txids_confirmed.unwrap(),
4398
4399                         best_block,
4400                         counterparty_node_id,
4401                         initial_counterparty_commitment_info,
4402                 })))
4403         }
4404 }
4405
4406 #[cfg(test)]
4407 mod tests {
4408         use bitcoin::blockdata::script::{Script, Builder};
4409         use bitcoin::blockdata::opcodes;
4410         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
4411         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
4412         use bitcoin::util::sighash;
4413         use bitcoin::hashes::Hash;
4414         use bitcoin::hashes::sha256::Hash as Sha256;
4415         use bitcoin::hashes::hex::FromHex;
4416         use bitcoin::hash_types::{BlockHash, Txid};
4417         use bitcoin::network::constants::Network;
4418         use bitcoin::secp256k1::{SecretKey,PublicKey};
4419         use bitcoin::secp256k1::Secp256k1;
4420
4421         use hex;
4422
4423         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
4424
4425         use super::ChannelMonitorUpdateStep;
4426         use crate::{check_added_monitors, check_spends, get_local_commitment_txn, get_monitor, get_route_and_payment_hash, unwrap_send_err};
4427         use crate::chain::{BestBlock, Confirm};
4428         use crate::chain::channelmonitor::ChannelMonitor;
4429         use crate::chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
4430         use crate::chain::transaction::OutPoint;
4431         use crate::sign::InMemorySigner;
4432         use crate::ln::{PaymentPreimage, PaymentHash};
4433         use crate::ln::chan_utils;
4434         use crate::ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
4435         use crate::ln::channelmanager::{PaymentSendFailure, PaymentId, RecipientOnionFields};
4436         use crate::ln::functional_test_utils::*;
4437         use crate::ln::script::ShutdownScript;
4438         use crate::util::errors::APIError;
4439         use crate::util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
4440         use crate::util::ser::{ReadableArgs, Writeable};
4441         use crate::sync::{Arc, Mutex};
4442         use crate::io;
4443         use bitcoin::{PackedLockTime, Sequence, Witness};
4444         use crate::ln::features::ChannelTypeFeatures;
4445         use crate::prelude::*;
4446
4447         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
4448                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
4449                 // confirmed. This would allow a race condition where we could receive a payment (including
4450                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
4451                 // long as the ChannelMonitor receives the block first, the full commitment update dance
4452                 // occurs after the block is connected, and before the ChannelManager receives the block.
4453                 // Obviously this is an incredibly contrived race given the counterparty would be risking
4454                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
4455                 // potential ChannelMonitor states simpler to reason about.
4456                 //
4457                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
4458                 // updates is handled correctly in such conditions.
4459                 let chanmon_cfgs = create_chanmon_cfgs(3);
4460                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
4461                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
4462                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
4463                 let channel = create_announced_chan_between_nodes(&nodes, 0, 1);
4464                 create_announced_chan_between_nodes(&nodes, 1, 2);
4465
4466                 // Rebalance somewhat
4467                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
4468
4469                 // First route two payments for testing at the end
4470                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4471                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
4472
4473                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
4474                 assert_eq!(local_txn.len(), 1);
4475                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
4476                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
4477                 check_spends!(remote_txn[1], remote_txn[0]);
4478                 check_spends!(remote_txn[2], remote_txn[0]);
4479                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
4480
4481                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
4482                 // channel is now closed, but the ChannelManager doesn't know that yet.
4483                 let new_header = create_dummy_header(nodes[0].best_block_info().0, 0);
4484                 let conf_height = nodes[0].best_block_info().1 + 1;
4485                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
4486                         &[(0, broadcast_tx)], conf_height);
4487
4488                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
4489                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
4490                                                 (&nodes[1].keys_manager.backing, &nodes[1].keys_manager.backing)).unwrap();
4491
4492                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
4493                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
4494                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
4495                 unwrap_send_err!(nodes[1].node.send_payment_with_route(&route, payment_hash,
4496                                 RecipientOnionFields::secret_only(payment_secret), PaymentId(payment_hash.0)
4497                         ), false, APIError::MonitorUpdateInProgress, {});
4498                 check_added_monitors!(nodes[1], 1);
4499
4500                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
4501                 // and provides the claim preimages for the two pending HTLCs. The first update generates
4502                 // an error, but the point of this test is to ensure the later updates are still applied.
4503                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
4504                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().next().unwrap().clone();
4505                 assert_eq!(replay_update.updates.len(), 1);
4506                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
4507                 } else { panic!(); }
4508                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
4509                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
4510
4511                 let broadcaster = TestBroadcaster::with_blocks(Arc::clone(&nodes[1].blocks));
4512                 assert!(
4513                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
4514                         .is_err());
4515                 // Even though we error'd on the first update, we should still have generated an HTLC claim
4516                 // transaction
4517                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
4518                 assert!(txn_broadcasted.len() >= 2);
4519                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
4520                         assert_eq!(tx.input.len(), 1);
4521                         tx.input[0].previous_output.txid == broadcast_tx.txid()
4522                 }).collect::<Vec<_>>();
4523                 assert_eq!(htlc_txn.len(), 2);
4524                 check_spends!(htlc_txn[0], broadcast_tx);
4525                 check_spends!(htlc_txn[1], broadcast_tx);
4526         }
4527         #[test]
4528         fn test_funding_spend_refuses_updates() {
4529                 do_test_funding_spend_refuses_updates(true);
4530                 do_test_funding_spend_refuses_updates(false);
4531         }
4532
4533         #[test]
4534         fn test_prune_preimages() {
4535                 let secp_ctx = Secp256k1::new();
4536                 let logger = Arc::new(TestLogger::new());
4537                 let broadcaster = Arc::new(TestBroadcaster::new(Network::Testnet));
4538                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
4539
4540                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4541
4542                 let mut preimages = Vec::new();
4543                 {
4544                         for i in 0..20 {
4545                                 let preimage = PaymentPreimage([i; 32]);
4546                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
4547                                 preimages.push((preimage, hash));
4548                         }
4549                 }
4550
4551                 macro_rules! preimages_slice_to_htlcs {
4552                         ($preimages_slice: expr) => {
4553                                 {
4554                                         let mut res = Vec::new();
4555                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
4556                                                 res.push((HTLCOutputInCommitment {
4557                                                         offered: true,
4558                                                         amount_msat: 0,
4559                                                         cltv_expiry: 0,
4560                                                         payment_hash: preimage.1.clone(),
4561                                                         transaction_output_index: Some(idx as u32),
4562                                                 }, ()));
4563                                         }
4564                                         res
4565                                 }
4566                         }
4567                 }
4568                 macro_rules! preimages_slice_to_htlc_outputs {
4569                         ($preimages_slice: expr) => {
4570                                 preimages_slice_to_htlcs!($preimages_slice).into_iter().map(|(htlc, _)| (htlc, None)).collect()
4571                         }
4572                 }
4573                 let dummy_sig = crate::util::crypto::sign(&secp_ctx,
4574                         &bitcoin::secp256k1::Message::from_slice(&[42; 32]).unwrap(),
4575                         &SecretKey::from_slice(&[42; 32]).unwrap());
4576
4577                 macro_rules! test_preimages_exist {
4578                         ($preimages_slice: expr, $monitor: expr) => {
4579                                 for preimage in $preimages_slice {
4580                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
4581                                 }
4582                         }
4583                 }
4584
4585                 let keys = InMemorySigner::new(
4586                         &secp_ctx,
4587                         SecretKey::from_slice(&[41; 32]).unwrap(),
4588                         SecretKey::from_slice(&[41; 32]).unwrap(),
4589                         SecretKey::from_slice(&[41; 32]).unwrap(),
4590                         SecretKey::from_slice(&[41; 32]).unwrap(),
4591                         SecretKey::from_slice(&[41; 32]).unwrap(),
4592                         [41; 32],
4593                         0,
4594                         [0; 32],
4595                         [0; 32],
4596                 );
4597
4598                 let counterparty_pubkeys = ChannelPublicKeys {
4599                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
4600                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
4601                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
4602                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
4603                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
4604                 };
4605                 let funding_outpoint = OutPoint { txid: Txid::all_zeros(), index: u16::max_value() };
4606                 let channel_parameters = ChannelTransactionParameters {
4607                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
4608                         holder_selected_contest_delay: 66,
4609                         is_outbound_from_holder: true,
4610                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
4611                                 pubkeys: counterparty_pubkeys,
4612                                 selected_contest_delay: 67,
4613                         }),
4614                         funding_outpoint: Some(funding_outpoint),
4615                         channel_type_features: ChannelTypeFeatures::only_static_remote_key()
4616                 };
4617                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
4618                 // old state.
4619                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
4620                 let best_block = BestBlock::from_network(Network::Testnet);
4621                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
4622                         Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
4623                         (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
4624                         &channel_parameters, Script::new(), 46, 0, HolderCommitmentTransaction::dummy(&mut Vec::new()),
4625                         best_block, dummy_key);
4626
4627                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..10]);
4628                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4629                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
4630                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4631                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"1").into_inner()),
4632                         preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
4633                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"2").into_inner()),
4634                         preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
4635                 for &(ref preimage, ref hash) in preimages.iter() {
4636                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
4637                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
4638                 }
4639
4640                 // Now provide a secret, pruning preimages 10-15
4641                 let mut secret = [0; 32];
4642                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
4643                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
4644                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
4645                 test_preimages_exist!(&preimages[0..10], monitor);
4646                 test_preimages_exist!(&preimages[15..20], monitor);
4647
4648                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"3").into_inner()),
4649                         preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
4650
4651                 // Now provide a further secret, pruning preimages 15-17
4652                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
4653                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
4654                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
4655                 test_preimages_exist!(&preimages[0..10], monitor);
4656                 test_preimages_exist!(&preimages[17..20], monitor);
4657
4658                 monitor.provide_latest_counterparty_commitment_tx(Txid::from_inner(Sha256::hash(b"4").into_inner()),
4659                         preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
4660
4661                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
4662                 // previous commitment tx's preimages too
4663                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..5]);
4664                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4665                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
4666                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4667                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
4668                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
4669                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
4670                 test_preimages_exist!(&preimages[0..10], monitor);
4671                 test_preimages_exist!(&preimages[18..20], monitor);
4672
4673                 // But if we do it again, we'll prune 5-10
4674                 let mut htlcs = preimages_slice_to_htlcs!(preimages[0..3]);
4675                 let dummy_commitment_tx = HolderCommitmentTransaction::dummy(&mut htlcs);
4676                 monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx,
4677                         htlcs.into_iter().map(|(htlc, _)| (htlc, Some(dummy_sig), None)).collect()).unwrap();
4678                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
4679                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
4680                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
4681                 test_preimages_exist!(&preimages[0..5], monitor);
4682         }
4683
4684         #[test]
4685         fn test_claim_txn_weight_computation() {
4686                 // We test Claim txn weight, knowing that we want expected weigth and
4687                 // not actual case to avoid sigs and time-lock delays hell variances.
4688
4689                 let secp_ctx = Secp256k1::new();
4690                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
4691                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
4692
4693                 macro_rules! sign_input {
4694                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
4695                                 let htlc = HTLCOutputInCommitment {
4696                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
4697                                         amount_msat: 0,
4698                                         cltv_expiry: 2 << 16,
4699                                         payment_hash: PaymentHash([1; 32]),
4700                                         transaction_output_index: Some($idx as u32),
4701                                 };
4702                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
4703                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
4704                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
4705                                 let mut ser_sig = sig.serialize_der().to_vec();
4706                                 ser_sig.push(EcdsaSighashType::All as u8);
4707                                 $sum_actual_sigs += ser_sig.len();
4708                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
4709                                 witness.push(ser_sig);
4710                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
4711                                         witness.push(vec!(1));
4712                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
4713                                         witness.push(pubkey.clone().serialize().to_vec());
4714                                 } else if *$weight == weight_received_htlc($opt_anchors) {
4715                                         witness.push(vec![0]);
4716                                 } else {
4717                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
4718                                 }
4719                                 witness.push(redeem_script.into_bytes());
4720                                 let witness = witness.to_vec();
4721                                 println!("witness[0] {}", witness[0].len());
4722                                 println!("witness[1] {}", witness[1].len());
4723                                 println!("witness[2] {}", witness[2].len());
4724                         }
4725                 }
4726
4727                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
4728                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
4729
4730                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
4731                 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
4732                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4733                         let mut sum_actual_sigs = 0;
4734                         for i in 0..4 {
4735                                 claim_tx.input.push(TxIn {
4736                                         previous_output: BitcoinOutPoint {
4737                                                 txid,
4738                                                 vout: i,
4739                                         },
4740                                         script_sig: Script::new(),
4741                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4742                                         witness: Witness::new(),
4743                                 });
4744                         }
4745                         claim_tx.output.push(TxOut {
4746                                 script_pubkey: script_pubkey.clone(),
4747                                 value: 0,
4748                         });
4749                         let base_weight = claim_tx.weight();
4750                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(channel_type_features), weight_revoked_offered_htlc(channel_type_features), weight_revoked_received_htlc(channel_type_features)];
4751                         let mut inputs_total_weight = 2; // count segwit flags
4752                         {
4753                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4754                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4755                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
4756                                         inputs_total_weight += inp;
4757                                 }
4758                         }
4759                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4760                 }
4761
4762                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
4763                 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
4764                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4765                         let mut sum_actual_sigs = 0;
4766                         for i in 0..4 {
4767                                 claim_tx.input.push(TxIn {
4768                                         previous_output: BitcoinOutPoint {
4769                                                 txid,
4770                                                 vout: i,
4771                                         },
4772                                         script_sig: Script::new(),
4773                                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4774                                         witness: Witness::new(),
4775                                 });
4776                         }
4777                         claim_tx.output.push(TxOut {
4778                                 script_pubkey: script_pubkey.clone(),
4779                                 value: 0,
4780                         });
4781                         let base_weight = claim_tx.weight();
4782                         let inputs_weight = vec![weight_offered_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features), weight_received_htlc(channel_type_features)];
4783                         let mut inputs_total_weight = 2; // count segwit flags
4784                         {
4785                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4786                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4787                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
4788                                         inputs_total_weight += inp;
4789                                 }
4790                         }
4791                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
4792                 }
4793
4794                 // Justice tx with 1 revoked HTLC-Success tx output
4795                 for channel_type_features in [ChannelTypeFeatures::only_static_remote_key(), ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies()].iter() {
4796                         let mut claim_tx = Transaction { version: 0, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
4797                         let mut sum_actual_sigs = 0;
4798                         claim_tx.input.push(TxIn {
4799                                 previous_output: BitcoinOutPoint {
4800                                         txid,
4801                                         vout: 0,
4802                                 },
4803                                 script_sig: Script::new(),
4804                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
4805                                 witness: Witness::new(),
4806                         });
4807                         claim_tx.output.push(TxOut {
4808                                 script_pubkey: script_pubkey.clone(),
4809                                 value: 0,
4810                         });
4811                         let base_weight = claim_tx.weight();
4812                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
4813                         let mut inputs_total_weight = 2; // count segwit flags
4814                         {
4815                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
4816                                 for (idx, inp) in inputs_weight.iter().enumerate() {
4817                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, channel_type_features);
4818                                         inputs_total_weight += inp;
4819                                 }
4820                         }
4821                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
4822                 }
4823         }
4824
4825         // Further testing is done in the ChannelManager integration tests.
4826 }