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Merge pull request #1472 from TheBlueMatt/2022-06-less-secp-ctx
[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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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::{TxOut,Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
27
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
31
32 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
33 use bitcoin::secp256k1::{SecretKey, PublicKey};
34 use bitcoin::secp256k1;
35
36 use ln::{PaymentHash, PaymentPreimage};
37 use ln::msgs::DecodeError;
38 use ln::chan_utils;
39 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use ln::channelmanager::HTLCSource;
41 use chain;
42 use chain::{BestBlock, WatchedOutput};
43 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
44 use chain::transaction::{OutPoint, TransactionData};
45 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
46 use chain::onchaintx::OnchainTxHandler;
47 use chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
48 use chain::Filter;
49 use util::logger::Logger;
50 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48, OptionDeserWrapper};
51 use util::byte_utils;
52 use util::events::Event;
53
54 use prelude::*;
55 use core::{cmp, mem};
56 use io::{self, Error};
57 use core::ops::Deref;
58 use sync::Mutex;
59
60 /// An update generated by the underlying Channel itself which contains some new information the
61 /// ChannelMonitor should be made aware of.
62 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq))]
63 #[derive(Clone)]
64 #[must_use]
65 pub struct ChannelMonitorUpdate {
66         pub(crate) updates: Vec<ChannelMonitorUpdateStep>,
67         /// The sequence number of this update. Updates *must* be replayed in-order according to this
68         /// sequence number (and updates may panic if they are not). The update_id values are strictly
69         /// increasing and increase by one for each new update, with one exception specified below.
70         ///
71         /// This sequence number is also used to track up to which points updates which returned
72         /// ChannelMonitorUpdateErr::TemporaryFailure have been applied to all copies of a given
73         /// ChannelMonitor when ChannelManager::channel_monitor_updated is called.
74         ///
75         /// The only instance where update_id values are not strictly increasing is the case where we
76         /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
77         /// its docs for more details.
78         pub update_id: u64,
79 }
80
81 /// If:
82 ///    (1) a channel has been force closed and
83 ///    (2) we receive a preimage from a forward link that allows us to spend an HTLC output on
84 ///        this channel's (the backward link's) broadcasted commitment transaction
85 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
86 /// with the update providing said payment preimage. No other update types are allowed after
87 /// force-close.
88 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
89
90 impl Writeable for ChannelMonitorUpdate {
91         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
92                 write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
93                 self.update_id.write(w)?;
94                 (self.updates.len() as u64).write(w)?;
95                 for update_step in self.updates.iter() {
96                         update_step.write(w)?;
97                 }
98                 write_tlv_fields!(w, {});
99                 Ok(())
100         }
101 }
102 impl Readable for ChannelMonitorUpdate {
103         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
104                 let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
105                 let update_id: u64 = Readable::read(r)?;
106                 let len: u64 = Readable::read(r)?;
107                 let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
108                 for _ in 0..len {
109                         if let Some(upd) = MaybeReadable::read(r)? {
110                                 updates.push(upd);
111                         }
112                 }
113                 read_tlv_fields!(r, {});
114                 Ok(Self { update_id, updates })
115         }
116 }
117
118 /// An event to be processed by the ChannelManager.
119 #[derive(Clone, PartialEq)]
120 pub enum MonitorEvent {
121         /// A monitor event containing an HTLCUpdate.
122         HTLCEvent(HTLCUpdate),
123
124         /// A monitor event that the Channel's commitment transaction was confirmed.
125         CommitmentTxConfirmed(OutPoint),
126
127         /// Indicates a [`ChannelMonitor`] update has completed. See
128         /// [`ChannelMonitorUpdateErr::TemporaryFailure`] for more information on how this is used.
129         ///
130         /// [`ChannelMonitorUpdateErr::TemporaryFailure`]: super::ChannelMonitorUpdateErr::TemporaryFailure
131         UpdateCompleted {
132                 /// The funding outpoint of the [`ChannelMonitor`] that was updated
133                 funding_txo: OutPoint,
134                 /// The Update ID from [`ChannelMonitorUpdate::update_id`] which was applied or
135                 /// [`ChannelMonitor::get_latest_update_id`].
136                 ///
137                 /// Note that this should only be set to a given update's ID if all previous updates for the
138                 /// same [`ChannelMonitor`] have been applied and persisted.
139                 monitor_update_id: u64,
140         },
141
142         /// Indicates a [`ChannelMonitor`] update has failed. See
143         /// [`ChannelMonitorUpdateErr::PermanentFailure`] for more information on how this is used.
144         ///
145         /// [`ChannelMonitorUpdateErr::PermanentFailure`]: super::ChannelMonitorUpdateErr::PermanentFailure
146         UpdateFailed(OutPoint),
147 }
148 impl_writeable_tlv_based_enum_upgradable!(MonitorEvent,
149         // Note that UpdateCompleted and UpdateFailed are currently never serialized to disk as they are
150         // generated only in ChainMonitor
151         (0, UpdateCompleted) => {
152                 (0, funding_txo, required),
153                 (2, monitor_update_id, required),
154         },
155 ;
156         (2, HTLCEvent),
157         (4, CommitmentTxConfirmed),
158         (6, UpdateFailed),
159 );
160
161 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
162 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
163 /// preimage claim backward will lead to loss of funds.
164 #[derive(Clone, PartialEq)]
165 pub struct HTLCUpdate {
166         pub(crate) payment_hash: PaymentHash,
167         pub(crate) payment_preimage: Option<PaymentPreimage>,
168         pub(crate) source: HTLCSource,
169         pub(crate) onchain_value_satoshis: Option<u64>,
170 }
171 impl_writeable_tlv_based!(HTLCUpdate, {
172         (0, payment_hash, required),
173         (1, onchain_value_satoshis, option),
174         (2, source, required),
175         (4, payment_preimage, option),
176 });
177
178 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
179 /// instead claiming it in its own individual transaction.
180 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
181 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
182 /// HTLC-Success transaction.
183 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
184 /// transaction confirmed (and we use it in a few more, equivalent, places).
185 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
186 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
187 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
188 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
189 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
190 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
191 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
192 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
193 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
194 /// accurate block height.
195 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
196 /// with at worst this delay, so we are not only using this value as a mercy for them but also
197 /// us as a safeguard to delay with enough time.
198 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
199 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding
200 /// inbound HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us
201 /// losing money.
202 ///
203 /// Note that this is a library-wide security assumption. If a reorg deeper than this number of
204 /// blocks occurs, counterparties may be able to steal funds or claims made by and balances exposed
205 /// by a  [`ChannelMonitor`] may be incorrect.
206 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
207 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
208 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
209 // keep bumping another claim tx to solve the outpoint.
210 pub const ANTI_REORG_DELAY: u32 = 6;
211 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
212 /// refuse to accept a new HTLC.
213 ///
214 /// This is used for a few separate purposes:
215 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
216 ///    waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
217 ///    fail this HTLC,
218 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
219 ///    condition with the above), we will fail this HTLC without telling the user we received it,
220 ///
221 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
222 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
223 ///
224 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
225 /// in a race condition between the user connecting a block (which would fail it) and the user
226 /// providing us the preimage (which would claim it).
227 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
228
229 // TODO(devrandom) replace this with HolderCommitmentTransaction
230 #[derive(Clone, PartialEq)]
231 struct HolderSignedTx {
232         /// txid of the transaction in tx, just used to make comparison faster
233         txid: Txid,
234         revocation_key: PublicKey,
235         a_htlc_key: PublicKey,
236         b_htlc_key: PublicKey,
237         delayed_payment_key: PublicKey,
238         per_commitment_point: PublicKey,
239         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
240         to_self_value_sat: u64,
241         feerate_per_kw: u32,
242 }
243 impl_writeable_tlv_based!(HolderSignedTx, {
244         (0, txid, required),
245         // Note that this is filled in with data from OnchainTxHandler if it's missing.
246         // For HolderSignedTx objects serialized with 0.0.100+, this should be filled in.
247         (1, to_self_value_sat, (default_value, u64::max_value())),
248         (2, revocation_key, required),
249         (4, a_htlc_key, required),
250         (6, b_htlc_key, required),
251         (8, delayed_payment_key, required),
252         (10, per_commitment_point, required),
253         (12, feerate_per_kw, required),
254         (14, htlc_outputs, vec_type)
255 });
256
257 /// We use this to track static counterparty commitment transaction data and to generate any
258 /// justice or 2nd-stage preimage/timeout transactions.
259 #[derive(PartialEq)]
260 struct CounterpartyCommitmentParameters {
261         counterparty_delayed_payment_base_key: PublicKey,
262         counterparty_htlc_base_key: PublicKey,
263         on_counterparty_tx_csv: u16,
264 }
265
266 impl Writeable for CounterpartyCommitmentParameters {
267         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
268                 w.write_all(&byte_utils::be64_to_array(0))?;
269                 write_tlv_fields!(w, {
270                         (0, self.counterparty_delayed_payment_base_key, required),
271                         (2, self.counterparty_htlc_base_key, required),
272                         (4, self.on_counterparty_tx_csv, required),
273                 });
274                 Ok(())
275         }
276 }
277 impl Readable for CounterpartyCommitmentParameters {
278         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
279                 let counterparty_commitment_transaction = {
280                         // Versions prior to 0.0.100 had some per-HTLC state stored here, which is no longer
281                         // used. Read it for compatibility.
282                         let per_htlc_len: u64 = Readable::read(r)?;
283                         for _  in 0..per_htlc_len {
284                                 let _txid: Txid = Readable::read(r)?;
285                                 let htlcs_count: u64 = Readable::read(r)?;
286                                 for _ in 0..htlcs_count {
287                                         let _htlc: HTLCOutputInCommitment = Readable::read(r)?;
288                                 }
289                         }
290
291                         let mut counterparty_delayed_payment_base_key = OptionDeserWrapper(None);
292                         let mut counterparty_htlc_base_key = OptionDeserWrapper(None);
293                         let mut on_counterparty_tx_csv: u16 = 0;
294                         read_tlv_fields!(r, {
295                                 (0, counterparty_delayed_payment_base_key, required),
296                                 (2, counterparty_htlc_base_key, required),
297                                 (4, on_counterparty_tx_csv, required),
298                         });
299                         CounterpartyCommitmentParameters {
300                                 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
301                                 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
302                                 on_counterparty_tx_csv,
303                         }
304                 };
305                 Ok(counterparty_commitment_transaction)
306         }
307 }
308
309 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
310 /// transaction causing it.
311 ///
312 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
313 #[derive(PartialEq)]
314 struct OnchainEventEntry {
315         txid: Txid,
316         height: u32,
317         event: OnchainEvent,
318 }
319
320 impl OnchainEventEntry {
321         fn confirmation_threshold(&self) -> u32 {
322                 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
323                 match self.event {
324                         OnchainEvent::MaturingOutput {
325                                 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
326                         } => {
327                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
328                                 // it's broadcastable when we see the previous block.
329                                 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
330                         },
331                         OnchainEvent::FundingSpendConfirmation { on_local_output_csv: Some(csv), .. } |
332                         OnchainEvent::HTLCSpendConfirmation { on_to_local_output_csv: Some(csv), .. } => {
333                                 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
334                                 // it's broadcastable when we see the previous block.
335                                 conf_threshold = cmp::max(conf_threshold, self.height + csv as u32 - 1);
336                         },
337                         _ => {},
338                 }
339                 conf_threshold
340         }
341
342         fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
343                 best_block.height() >= self.confirmation_threshold()
344         }
345 }
346
347 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
348 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
349 #[derive(PartialEq)]
350 enum OnchainEvent {
351         /// An outbound HTLC failing after a transaction is confirmed. Used
352         ///  * when an outbound HTLC output is spent by us after the HTLC timed out
353         ///  * an outbound HTLC which was not present in the commitment transaction which appeared
354         ///    on-chain (either because it was not fully committed to or it was dust).
355         /// Note that this is *not* used for preimage claims, as those are passed upstream immediately,
356         /// appearing only as an `HTLCSpendConfirmation`, below.
357         HTLCUpdate {
358                 source: HTLCSource,
359                 payment_hash: PaymentHash,
360                 onchain_value_satoshis: Option<u64>,
361                 /// None in the second case, above, ie when there is no relevant output in the commitment
362                 /// transaction which appeared on chain.
363                 input_idx: Option<u32>,
364         },
365         MaturingOutput {
366                 descriptor: SpendableOutputDescriptor,
367         },
368         /// A spend of the funding output, either a commitment transaction or a cooperative closing
369         /// transaction.
370         FundingSpendConfirmation {
371                 /// The CSV delay for the output of the funding spend transaction (implying it is a local
372                 /// commitment transaction, and this is the delay on the to_self output).
373                 on_local_output_csv: Option<u16>,
374         },
375         /// A spend of a commitment transaction HTLC output, set in the cases where *no* `HTLCUpdate`
376         /// is constructed. This is used when
377         ///  * an outbound HTLC is claimed by our counterparty with a preimage, causing us to
378         ///    immediately claim the HTLC on the inbound edge and track the resolution here,
379         ///  * an inbound HTLC is claimed by our counterparty (with a timeout),
380         ///  * an inbound HTLC is claimed by us (with a preimage).
381         ///  * a revoked-state HTLC transaction was broadcasted, which was claimed by the revocation
382         ///    signature.
383         HTLCSpendConfirmation {
384                 input_idx: u32,
385                 /// If the claim was made by either party with a preimage, this is filled in
386                 preimage: Option<PaymentPreimage>,
387                 /// If the claim was made by us on an inbound HTLC against a local commitment transaction,
388                 /// we set this to the output CSV value which we will have to wait until to spend the
389                 /// output (and generate a SpendableOutput event).
390                 on_to_local_output_csv: Option<u16>,
391         },
392 }
393
394 impl Writeable for OnchainEventEntry {
395         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
396                 write_tlv_fields!(writer, {
397                         (0, self.txid, required),
398                         (2, self.height, required),
399                         (4, self.event, required),
400                 });
401                 Ok(())
402         }
403 }
404
405 impl MaybeReadable for OnchainEventEntry {
406         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
407                 let mut txid = Default::default();
408                 let mut height = 0;
409                 let mut event = None;
410                 read_tlv_fields!(reader, {
411                         (0, txid, required),
412                         (2, height, required),
413                         (4, event, ignorable),
414                 });
415                 if let Some(ev) = event {
416                         Ok(Some(Self { txid, height, event: ev }))
417                 } else {
418                         Ok(None)
419                 }
420         }
421 }
422
423 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
424         (0, HTLCUpdate) => {
425                 (0, source, required),
426                 (1, onchain_value_satoshis, option),
427                 (2, payment_hash, required),
428                 (3, input_idx, option),
429         },
430         (1, MaturingOutput) => {
431                 (0, descriptor, required),
432         },
433         (3, FundingSpendConfirmation) => {
434                 (0, on_local_output_csv, option),
435         },
436         (5, HTLCSpendConfirmation) => {
437                 (0, input_idx, required),
438                 (2, preimage, option),
439                 (4, on_to_local_output_csv, option),
440         },
441
442 );
443
444 #[cfg_attr(any(test, fuzzing, feature = "_test_utils"), derive(PartialEq))]
445 #[derive(Clone)]
446 pub(crate) enum ChannelMonitorUpdateStep {
447         LatestHolderCommitmentTXInfo {
448                 commitment_tx: HolderCommitmentTransaction,
449                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
450         },
451         LatestCounterpartyCommitmentTXInfo {
452                 commitment_txid: Txid,
453                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
454                 commitment_number: u64,
455                 their_revocation_point: PublicKey,
456         },
457         PaymentPreimage {
458                 payment_preimage: PaymentPreimage,
459         },
460         CommitmentSecret {
461                 idx: u64,
462                 secret: [u8; 32],
463         },
464         /// Used to indicate that the no future updates will occur, and likely that the latest holder
465         /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
466         ChannelForceClosed {
467                 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
468                 /// think we've fallen behind!
469                 should_broadcast: bool,
470         },
471         ShutdownScript {
472                 scriptpubkey: Script,
473         },
474 }
475
476 impl ChannelMonitorUpdateStep {
477         fn variant_name(&self) -> &'static str {
478                 match self {
479                         ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { .. } => "LatestHolderCommitmentTXInfo",
480                         ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } => "LatestCounterpartyCommitmentTXInfo",
481                         ChannelMonitorUpdateStep::PaymentPreimage { .. } => "PaymentPreimage",
482                         ChannelMonitorUpdateStep::CommitmentSecret { .. } => "CommitmentSecret",
483                         ChannelMonitorUpdateStep::ChannelForceClosed { .. } => "ChannelForceClosed",
484                         ChannelMonitorUpdateStep::ShutdownScript { .. } => "ShutdownScript",
485                 }
486         }
487 }
488
489 impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
490         (0, LatestHolderCommitmentTXInfo) => {
491                 (0, commitment_tx, required),
492                 (2, htlc_outputs, vec_type),
493         },
494         (1, LatestCounterpartyCommitmentTXInfo) => {
495                 (0, commitment_txid, required),
496                 (2, commitment_number, required),
497                 (4, their_revocation_point, required),
498                 (6, htlc_outputs, vec_type),
499         },
500         (2, PaymentPreimage) => {
501                 (0, payment_preimage, required),
502         },
503         (3, CommitmentSecret) => {
504                 (0, idx, required),
505                 (2, secret, required),
506         },
507         (4, ChannelForceClosed) => {
508                 (0, should_broadcast, required),
509         },
510         (5, ShutdownScript) => {
511                 (0, scriptpubkey, required),
512         },
513 );
514
515 /// Details about the balance(s) available for spending once the channel appears on chain.
516 ///
517 /// See [`ChannelMonitor::get_claimable_balances`] for more details on when these will or will not
518 /// be provided.
519 #[derive(Clone, Debug, PartialEq, Eq)]
520 #[cfg_attr(test, derive(PartialOrd, Ord))]
521 pub enum Balance {
522         /// The channel is not yet closed (or the commitment or closing transaction has not yet
523         /// appeared in a block). The given balance is claimable (less on-chain fees) if the channel is
524         /// force-closed now.
525         ClaimableOnChannelClose {
526                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
527                 /// required to do so.
528                 claimable_amount_satoshis: u64,
529         },
530         /// The channel has been closed, and the given balance is ours but awaiting confirmations until
531         /// we consider it spendable.
532         ClaimableAwaitingConfirmations {
533                 /// The amount available to claim, in satoshis, possibly excluding the on-chain fees which
534                 /// were spent in broadcasting the transaction.
535                 claimable_amount_satoshis: u64,
536                 /// The height at which an [`Event::SpendableOutputs`] event will be generated for this
537                 /// amount.
538                 confirmation_height: u32,
539         },
540         /// The channel has been closed, and the given balance should be ours but awaiting spending
541         /// transaction confirmation. If the spending transaction does not confirm in time, it is
542         /// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
543         ///
544         /// Once the spending transaction confirms, before it has reached enough confirmations to be
545         /// considered safe from chain reorganizations, the balance will instead be provided via
546         /// [`Balance::ClaimableAwaitingConfirmations`].
547         ContentiousClaimable {
548                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
549                 /// required to do so.
550                 claimable_amount_satoshis: u64,
551                 /// The height at which the counterparty may be able to claim the balance if we have not
552                 /// done so.
553                 timeout_height: u32,
554         },
555         /// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
556         /// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
557         /// likely to be claimed by our counterparty before we do.
558         MaybeClaimableHTLCAwaitingTimeout {
559                 /// The amount available to claim, in satoshis, excluding the on-chain fees which will be
560                 /// required to do so.
561                 claimable_amount_satoshis: u64,
562                 /// The height at which we will be able to claim the balance if our counterparty has not
563                 /// done so.
564                 claimable_height: u32,
565         },
566 }
567
568 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
569 #[derive(PartialEq)]
570 struct IrrevocablyResolvedHTLC {
571         input_idx: u32,
572         /// Only set if the HTLC claim was ours using a payment preimage
573         payment_preimage: Option<PaymentPreimage>,
574 }
575
576 impl_writeable_tlv_based!(IrrevocablyResolvedHTLC, {
577         (0, input_idx, required),
578         (2, payment_preimage, option),
579 });
580
581 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
582 /// on-chain transactions to ensure no loss of funds occurs.
583 ///
584 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
585 /// information and are actively monitoring the chain.
586 ///
587 /// Pending Events or updated HTLCs which have not yet been read out by
588 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
589 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
590 /// gotten are fully handled before re-serializing the new state.
591 ///
592 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
593 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
594 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
595 /// returned block hash and the the current chain and then reconnecting blocks to get to the
596 /// best chain) upon deserializing the object!
597 pub struct ChannelMonitor<Signer: Sign> {
598         #[cfg(test)]
599         pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
600         #[cfg(not(test))]
601         inner: Mutex<ChannelMonitorImpl<Signer>>,
602 }
603
604 pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
605         latest_update_id: u64,
606         commitment_transaction_number_obscure_factor: u64,
607
608         destination_script: Script,
609         broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
610         counterparty_payment_script: Script,
611         shutdown_script: Option<Script>,
612
613         channel_keys_id: [u8; 32],
614         holder_revocation_basepoint: PublicKey,
615         funding_info: (OutPoint, Script),
616         current_counterparty_commitment_txid: Option<Txid>,
617         prev_counterparty_commitment_txid: Option<Txid>,
618
619         counterparty_commitment_params: CounterpartyCommitmentParameters,
620         funding_redeemscript: Script,
621         channel_value_satoshis: u64,
622         // first is the idx of the first of the two revocation points
623         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
624
625         on_holder_tx_csv: u16,
626
627         commitment_secrets: CounterpartyCommitmentSecrets,
628         /// The set of outpoints in each counterparty commitment transaction. We always need at least
629         /// the payment hash from `HTLCOutputInCommitment` to claim even a revoked commitment
630         /// transaction broadcast as we need to be able to construct the witness script in all cases.
631         counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
632         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
633         /// Nor can we figure out their commitment numbers without the commitment transaction they are
634         /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
635         /// commitment transactions which we find on-chain, mapping them to the commitment number which
636         /// can be used to derive the revocation key and claim the transactions.
637         counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
638         /// Cache used to make pruning of payment_preimages faster.
639         /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
640         /// counterparty transactions (ie should remain pretty small).
641         /// Serialized to disk but should generally not be sent to Watchtowers.
642         counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
643
644         // We store two holder commitment transactions to avoid any race conditions where we may update
645         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
646         // various monitors for one channel being out of sync, and us broadcasting a holder
647         // transaction for which we have deleted claim information on some watchtowers.
648         prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
649         current_holder_commitment_tx: HolderSignedTx,
650
651         // Used just for ChannelManager to make sure it has the latest channel data during
652         // deserialization
653         current_counterparty_commitment_number: u64,
654         // Used just for ChannelManager to make sure it has the latest channel data during
655         // deserialization
656         current_holder_commitment_number: u64,
657
658         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
659
660         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
661         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
662         // presumably user implementations thereof as well) where we update the in-memory channel
663         // object, then before the persistence finishes (as it's all under a read-lock), we return
664         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
665         // the pre-event state here, but have processed the event in the `ChannelManager`.
666         // Note that because the `event_lock` in `ChainMonitor` is only taken in
667         // block/transaction-connected events and *not* during block/transaction-disconnected events,
668         // we further MUST NOT generate events during block/transaction-disconnection.
669         pending_monitor_events: Vec<MonitorEvent>,
670
671         pending_events: Vec<Event>,
672
673         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
674         // which to take actions once they reach enough confirmations. Each entry includes the
675         // transaction's id and the height when the transaction was confirmed on chain.
676         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
677
678         // If we get serialized out and re-read, we need to make sure that the chain monitoring
679         // interface knows about the TXOs that we want to be notified of spends of. We could probably
680         // be smart and derive them from the above storage fields, but its much simpler and more
681         // Obviously Correct (tm) if we just keep track of them explicitly.
682         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
683
684         #[cfg(test)]
685         pub onchain_tx_handler: OnchainTxHandler<Signer>,
686         #[cfg(not(test))]
687         onchain_tx_handler: OnchainTxHandler<Signer>,
688
689         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
690         // channel has been force-closed. After this is set, no further holder commitment transaction
691         // updates may occur, and we panic!() if one is provided.
692         lockdown_from_offchain: bool,
693
694         // Set once we've signed a holder commitment transaction and handed it over to our
695         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
696         // may occur, and we fail any such monitor updates.
697         //
698         // In case of update rejection due to a locally already signed commitment transaction, we
699         // nevertheless store update content to track in case of concurrent broadcast by another
700         // remote monitor out-of-order with regards to the block view.
701         holder_tx_signed: bool,
702
703         // If a spend of the funding output is seen, we set this to true and reject any further
704         // updates. This prevents any further changes in the offchain state no matter the order
705         // of block connection between ChannelMonitors and the ChannelManager.
706         funding_spend_seen: bool,
707
708         funding_spend_confirmed: Option<Txid>,
709         /// The set of HTLCs which have been either claimed or failed on chain and have reached
710         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
711         /// spending CSV for revocable outputs).
712         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
713
714         // We simply modify best_block in Channel's block_connected so that serialization is
715         // consistent but hopefully the users' copy handles block_connected in a consistent way.
716         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
717         // their best_block from its state and not based on updated copies that didn't run through
718         // the full block_connected).
719         best_block: BestBlock,
720
721         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
722 }
723
724 /// Transaction outputs to watch for on-chain spends.
725 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
726
727 #[cfg(any(test, fuzzing, feature = "_test_utils"))]
728 /// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
729 /// object
730 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
731         fn eq(&self, other: &Self) -> bool {
732                 let inner = self.inner.lock().unwrap();
733                 let other = other.inner.lock().unwrap();
734                 inner.eq(&other)
735         }
736 }
737
738 #[cfg(any(test, fuzzing, feature = "_test_utils"))]
739 /// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
740 /// object
741 impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
742         fn eq(&self, other: &Self) -> bool {
743                 if self.latest_update_id != other.latest_update_id ||
744                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
745                         self.destination_script != other.destination_script ||
746                         self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
747                         self.counterparty_payment_script != other.counterparty_payment_script ||
748                         self.channel_keys_id != other.channel_keys_id ||
749                         self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
750                         self.funding_info != other.funding_info ||
751                         self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
752                         self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
753                         self.counterparty_commitment_params != other.counterparty_commitment_params ||
754                         self.funding_redeemscript != other.funding_redeemscript ||
755                         self.channel_value_satoshis != other.channel_value_satoshis ||
756                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
757                         self.on_holder_tx_csv != other.on_holder_tx_csv ||
758                         self.commitment_secrets != other.commitment_secrets ||
759                         self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
760                         self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
761                         self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
762                         self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
763                         self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
764                         self.current_holder_commitment_number != other.current_holder_commitment_number ||
765                         self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
766                         self.payment_preimages != other.payment_preimages ||
767                         self.pending_monitor_events != other.pending_monitor_events ||
768                         self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
769                         self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
770                         self.outputs_to_watch != other.outputs_to_watch ||
771                         self.lockdown_from_offchain != other.lockdown_from_offchain ||
772                         self.holder_tx_signed != other.holder_tx_signed ||
773                         self.funding_spend_seen != other.funding_spend_seen ||
774                         self.funding_spend_confirmed != other.funding_spend_confirmed ||
775                         self.htlcs_resolved_on_chain != other.htlcs_resolved_on_chain
776                 {
777                         false
778                 } else {
779                         true
780                 }
781         }
782 }
783
784 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
785         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
786                 self.inner.lock().unwrap().write(writer)
787         }
788 }
789
790 // These are also used for ChannelMonitorUpdate, above.
791 const SERIALIZATION_VERSION: u8 = 1;
792 const MIN_SERIALIZATION_VERSION: u8 = 1;
793
794 impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
795         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
796                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
797
798                 self.latest_update_id.write(writer)?;
799
800                 // Set in initial Channel-object creation, so should always be set by now:
801                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
802
803                 self.destination_script.write(writer)?;
804                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
805                         writer.write_all(&[0; 1])?;
806                         broadcasted_holder_revokable_script.0.write(writer)?;
807                         broadcasted_holder_revokable_script.1.write(writer)?;
808                         broadcasted_holder_revokable_script.2.write(writer)?;
809                 } else {
810                         writer.write_all(&[1; 1])?;
811                 }
812
813                 self.counterparty_payment_script.write(writer)?;
814                 match &self.shutdown_script {
815                         Some(script) => script.write(writer)?,
816                         None => Script::new().write(writer)?,
817                 }
818
819                 self.channel_keys_id.write(writer)?;
820                 self.holder_revocation_basepoint.write(writer)?;
821                 writer.write_all(&self.funding_info.0.txid[..])?;
822                 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
823                 self.funding_info.1.write(writer)?;
824                 self.current_counterparty_commitment_txid.write(writer)?;
825                 self.prev_counterparty_commitment_txid.write(writer)?;
826
827                 self.counterparty_commitment_params.write(writer)?;
828                 self.funding_redeemscript.write(writer)?;
829                 self.channel_value_satoshis.write(writer)?;
830
831                 match self.their_cur_revocation_points {
832                         Some((idx, pubkey, second_option)) => {
833                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
834                                 writer.write_all(&pubkey.serialize())?;
835                                 match second_option {
836                                         Some(second_pubkey) => {
837                                                 writer.write_all(&second_pubkey.serialize())?;
838                                         },
839                                         None => {
840                                                 writer.write_all(&[0; 33])?;
841                                         },
842                                 }
843                         },
844                         None => {
845                                 writer.write_all(&byte_utils::be48_to_array(0))?;
846                         },
847                 }
848
849                 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
850
851                 self.commitment_secrets.write(writer)?;
852
853                 macro_rules! serialize_htlc_in_commitment {
854                         ($htlc_output: expr) => {
855                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
856                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
857                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
858                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
859                                 $htlc_output.transaction_output_index.write(writer)?;
860                         }
861                 }
862
863                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
864                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
865                         writer.write_all(&txid[..])?;
866                         writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
867                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
868                                 serialize_htlc_in_commitment!(htlc_output);
869                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
870                         }
871                 }
872
873                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
874                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
875                         writer.write_all(&txid[..])?;
876                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
877                 }
878
879                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
880                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
881                         writer.write_all(&payment_hash.0[..])?;
882                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
883                 }
884
885                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
886                         writer.write_all(&[1; 1])?;
887                         prev_holder_tx.write(writer)?;
888                 } else {
889                         writer.write_all(&[0; 1])?;
890                 }
891
892                 self.current_holder_commitment_tx.write(writer)?;
893
894                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
895                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
896
897                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
898                 for payment_preimage in self.payment_preimages.values() {
899                         writer.write_all(&payment_preimage.0[..])?;
900                 }
901
902                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
903                         MonitorEvent::HTLCEvent(_) => true,
904                         MonitorEvent::CommitmentTxConfirmed(_) => true,
905                         _ => false,
906                 }).count() as u64).to_be_bytes())?;
907                 for event in self.pending_monitor_events.iter() {
908                         match event {
909                                 MonitorEvent::HTLCEvent(upd) => {
910                                         0u8.write(writer)?;
911                                         upd.write(writer)?;
912                                 },
913                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
914                                 _ => {}, // Covered in the TLV writes below
915                         }
916                 }
917
918                 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
919                 for event in self.pending_events.iter() {
920                         event.write(writer)?;
921                 }
922
923                 self.best_block.block_hash().write(writer)?;
924                 writer.write_all(&byte_utils::be32_to_array(self.best_block.height()))?;
925
926                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
927                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
928                         entry.write(writer)?;
929                 }
930
931                 (self.outputs_to_watch.len() as u64).write(writer)?;
932                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
933                         txid.write(writer)?;
934                         (idx_scripts.len() as u64).write(writer)?;
935                         for (idx, script) in idx_scripts.iter() {
936                                 idx.write(writer)?;
937                                 script.write(writer)?;
938                         }
939                 }
940                 self.onchain_tx_handler.write(writer)?;
941
942                 self.lockdown_from_offchain.write(writer)?;
943                 self.holder_tx_signed.write(writer)?;
944
945                 write_tlv_fields!(writer, {
946                         (1, self.funding_spend_confirmed, option),
947                         (3, self.htlcs_resolved_on_chain, vec_type),
948                         (5, self.pending_monitor_events, vec_type),
949                         (7, self.funding_spend_seen, required),
950                 });
951
952                 Ok(())
953         }
954 }
955
956 impl<Signer: Sign> ChannelMonitor<Signer> {
957         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
958                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
959                           channel_parameters: &ChannelTransactionParameters,
960                           funding_redeemscript: Script, channel_value_satoshis: u64,
961                           commitment_transaction_number_obscure_factor: u64,
962                           initial_holder_commitment_tx: HolderCommitmentTransaction,
963                           best_block: BestBlock) -> ChannelMonitor<Signer> {
964
965                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
966                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
967                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
968
969                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
970                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
971                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
972                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
973
974                 let channel_keys_id = keys.channel_keys_id();
975                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
976
977                 // block for Rust 1.34 compat
978                 let (holder_commitment_tx, current_holder_commitment_number) = {
979                         let trusted_tx = initial_holder_commitment_tx.trust();
980                         let txid = trusted_tx.txid();
981
982                         let tx_keys = trusted_tx.keys();
983                         let holder_commitment_tx = HolderSignedTx {
984                                 txid,
985                                 revocation_key: tx_keys.revocation_key,
986                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
987                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
988                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
989                                 per_commitment_point: tx_keys.per_commitment_point,
990                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
991                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
992                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
993                         };
994                         (holder_commitment_tx, trusted_tx.commitment_number())
995                 };
996
997                 let onchain_tx_handler =
998                         OnchainTxHandler::new(destination_script.clone(), keys,
999                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
1000
1001                 let mut outputs_to_watch = HashMap::new();
1002                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1003
1004                 ChannelMonitor {
1005                         inner: Mutex::new(ChannelMonitorImpl {
1006                                 latest_update_id: 0,
1007                                 commitment_transaction_number_obscure_factor,
1008
1009                                 destination_script: destination_script.clone(),
1010                                 broadcasted_holder_revokable_script: None,
1011                                 counterparty_payment_script,
1012                                 shutdown_script,
1013
1014                                 channel_keys_id,
1015                                 holder_revocation_basepoint,
1016                                 funding_info,
1017                                 current_counterparty_commitment_txid: None,
1018                                 prev_counterparty_commitment_txid: None,
1019
1020                                 counterparty_commitment_params,
1021                                 funding_redeemscript,
1022                                 channel_value_satoshis,
1023                                 their_cur_revocation_points: None,
1024
1025                                 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1026
1027                                 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1028                                 counterparty_claimable_outpoints: HashMap::new(),
1029                                 counterparty_commitment_txn_on_chain: HashMap::new(),
1030                                 counterparty_hash_commitment_number: HashMap::new(),
1031
1032                                 prev_holder_signed_commitment_tx: None,
1033                                 current_holder_commitment_tx: holder_commitment_tx,
1034                                 current_counterparty_commitment_number: 1 << 48,
1035                                 current_holder_commitment_number,
1036
1037                                 payment_preimages: HashMap::new(),
1038                                 pending_monitor_events: Vec::new(),
1039                                 pending_events: Vec::new(),
1040
1041                                 onchain_events_awaiting_threshold_conf: Vec::new(),
1042                                 outputs_to_watch,
1043
1044                                 onchain_tx_handler,
1045
1046                                 lockdown_from_offchain: false,
1047                                 holder_tx_signed: false,
1048                                 funding_spend_seen: false,
1049                                 funding_spend_confirmed: None,
1050                                 htlcs_resolved_on_chain: Vec::new(),
1051
1052                                 best_block,
1053
1054                                 secp_ctx,
1055                         }),
1056                 }
1057         }
1058
1059         #[cfg(test)]
1060         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1061                 self.inner.lock().unwrap().provide_secret(idx, secret)
1062         }
1063
1064         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1065         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1066         /// possibly future revocation/preimage information) to claim outputs where possible.
1067         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1068         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1069                 &self,
1070                 txid: Txid,
1071                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1072                 commitment_number: u64,
1073                 their_revocation_point: PublicKey,
1074                 logger: &L,
1075         ) where L::Target: Logger {
1076                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1077                         txid, htlc_outputs, commitment_number, their_revocation_point, logger)
1078         }
1079
1080         #[cfg(test)]
1081         fn provide_latest_holder_commitment_tx(
1082                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1083                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1084         ) -> Result<(), ()> {
1085                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs).map_err(|_| ())
1086         }
1087
1088         #[cfg(test)]
1089         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1090                 &self,
1091                 payment_hash: &PaymentHash,
1092                 payment_preimage: &PaymentPreimage,
1093                 broadcaster: &B,
1094                 fee_estimator: &F,
1095                 logger: &L,
1096         ) where
1097                 B::Target: BroadcasterInterface,
1098                 F::Target: FeeEstimator,
1099                 L::Target: Logger,
1100         {
1101                 self.inner.lock().unwrap().provide_payment_preimage(
1102                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1103         }
1104
1105         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1106                 &self,
1107                 broadcaster: &B,
1108                 logger: &L,
1109         ) where
1110                 B::Target: BroadcasterInterface,
1111                 L::Target: Logger,
1112         {
1113                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
1114         }
1115
1116         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1117         /// itself.
1118         ///
1119         /// panics if the given update is not the next update by update_id.
1120         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1121                 &self,
1122                 updates: &ChannelMonitorUpdate,
1123                 broadcaster: &B,
1124                 fee_estimator: &F,
1125                 logger: &L,
1126         ) -> Result<(), ()>
1127         where
1128                 B::Target: BroadcasterInterface,
1129                 F::Target: FeeEstimator,
1130                 L::Target: Logger,
1131         {
1132                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1133         }
1134
1135         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1136         /// ChannelMonitor.
1137         pub fn get_latest_update_id(&self) -> u64 {
1138                 self.inner.lock().unwrap().get_latest_update_id()
1139         }
1140
1141         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1142         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1143                 self.inner.lock().unwrap().get_funding_txo().clone()
1144         }
1145
1146         /// Gets a list of txids, with their output scripts (in the order they appear in the
1147         /// transaction), which we must learn about spends of via block_connected().
1148         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1149                 self.inner.lock().unwrap().get_outputs_to_watch()
1150                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1151         }
1152
1153         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1154         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1155         /// have been registered.
1156         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1157                 let lock = self.inner.lock().unwrap();
1158                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1159                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1160                         for (index, script_pubkey) in outputs.iter() {
1161                                 assert!(*index <= u16::max_value() as u32);
1162                                 filter.register_output(WatchedOutput {
1163                                         block_hash: None,
1164                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1165                                         script_pubkey: script_pubkey.clone(),
1166                                 });
1167                         }
1168                 }
1169         }
1170
1171         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1172         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1173         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1174                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1175         }
1176
1177         /// Gets the list of pending events which were generated by previous actions, clearing the list
1178         /// in the process.
1179         ///
1180         /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1181         /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1182         /// no internal locking in ChannelMonitors.
1183         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1184                 self.inner.lock().unwrap().get_and_clear_pending_events()
1185         }
1186
1187         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1188                 self.inner.lock().unwrap().get_min_seen_secret()
1189         }
1190
1191         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1192                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1193         }
1194
1195         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1196                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1197         }
1198
1199         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1200         /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1201         /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1202         /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1203         /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1204         /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1205         /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1206         /// out-of-band the other node operator to coordinate with him if option is available to you.
1207         /// In any-case, choice is up to the user.
1208         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1209         where L::Target: Logger {
1210                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1211         }
1212
1213         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1214         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1215         /// revoked commitment transaction.
1216         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1217         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1218         where L::Target: Logger {
1219                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1220         }
1221
1222         /// Processes transactions in a newly connected block, which may result in any of the following:
1223         /// - update the monitor's state against resolved HTLCs
1224         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1225         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1226         /// - detect settled outputs for later spending
1227         /// - schedule and bump any in-flight claims
1228         ///
1229         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1230         /// [`get_outputs_to_watch`].
1231         ///
1232         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1233         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1234                 &self,
1235                 header: &BlockHeader,
1236                 txdata: &TransactionData,
1237                 height: u32,
1238                 broadcaster: B,
1239                 fee_estimator: F,
1240                 logger: L,
1241         ) -> Vec<TransactionOutputs>
1242         where
1243                 B::Target: BroadcasterInterface,
1244                 F::Target: FeeEstimator,
1245                 L::Target: Logger,
1246         {
1247                 self.inner.lock().unwrap().block_connected(
1248                         header, txdata, height, broadcaster, fee_estimator, logger)
1249         }
1250
1251         /// Determines if the disconnected block contained any transactions of interest and updates
1252         /// appropriately.
1253         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1254                 &self,
1255                 header: &BlockHeader,
1256                 height: u32,
1257                 broadcaster: B,
1258                 fee_estimator: F,
1259                 logger: L,
1260         ) where
1261                 B::Target: BroadcasterInterface,
1262                 F::Target: FeeEstimator,
1263                 L::Target: Logger,
1264         {
1265                 self.inner.lock().unwrap().block_disconnected(
1266                         header, height, broadcaster, fee_estimator, logger)
1267         }
1268
1269         /// Processes transactions confirmed in a block with the given header and height, returning new
1270         /// outputs to watch. See [`block_connected`] for details.
1271         ///
1272         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1273         /// blocks. See [`chain::Confirm`] for calling expectations.
1274         ///
1275         /// [`block_connected`]: Self::block_connected
1276         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1277                 &self,
1278                 header: &BlockHeader,
1279                 txdata: &TransactionData,
1280                 height: u32,
1281                 broadcaster: B,
1282                 fee_estimator: F,
1283                 logger: L,
1284         ) -> Vec<TransactionOutputs>
1285         where
1286                 B::Target: BroadcasterInterface,
1287                 F::Target: FeeEstimator,
1288                 L::Target: Logger,
1289         {
1290                 self.inner.lock().unwrap().transactions_confirmed(
1291                         header, txdata, height, broadcaster, fee_estimator, logger)
1292         }
1293
1294         /// Processes a transaction that was reorganized out of the chain.
1295         ///
1296         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1297         /// than blocks. See [`chain::Confirm`] for calling expectations.
1298         ///
1299         /// [`block_disconnected`]: Self::block_disconnected
1300         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1301                 &self,
1302                 txid: &Txid,
1303                 broadcaster: B,
1304                 fee_estimator: F,
1305                 logger: L,
1306         ) where
1307                 B::Target: BroadcasterInterface,
1308                 F::Target: FeeEstimator,
1309                 L::Target: Logger,
1310         {
1311                 self.inner.lock().unwrap().transaction_unconfirmed(
1312                         txid, broadcaster, fee_estimator, logger);
1313         }
1314
1315         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1316         /// [`block_connected`] for details.
1317         ///
1318         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1319         /// blocks. See [`chain::Confirm`] for calling expectations.
1320         ///
1321         /// [`block_connected`]: Self::block_connected
1322         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1323                 &self,
1324                 header: &BlockHeader,
1325                 height: u32,
1326                 broadcaster: B,
1327                 fee_estimator: F,
1328                 logger: L,
1329         ) -> Vec<TransactionOutputs>
1330         where
1331                 B::Target: BroadcasterInterface,
1332                 F::Target: FeeEstimator,
1333                 L::Target: Logger,
1334         {
1335                 self.inner.lock().unwrap().best_block_updated(
1336                         header, height, broadcaster, fee_estimator, logger)
1337         }
1338
1339         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1340         pub fn get_relevant_txids(&self) -> Vec<Txid> {
1341                 let inner = self.inner.lock().unwrap();
1342                 let mut txids: Vec<Txid> = inner.onchain_events_awaiting_threshold_conf
1343                         .iter()
1344                         .map(|entry| entry.txid)
1345                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1346                         .collect();
1347                 txids.sort_unstable();
1348                 txids.dedup();
1349                 txids
1350         }
1351
1352         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1353         /// [`chain::Confirm`] interfaces.
1354         pub fn current_best_block(&self) -> BestBlock {
1355                 self.inner.lock().unwrap().best_block.clone()
1356         }
1357
1358         /// Gets the balances in this channel which are either claimable by us if we were to
1359         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1360         /// confirmation).
1361         ///
1362         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1363         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1364         /// balance, or until our counterparty has claimed the balance and accrued several
1365         /// confirmations on the claim transaction.
1366         ///
1367         /// Note that the balances available when you or your counterparty have broadcasted revoked
1368         /// state(s) may not be fully captured here.
1369         // TODO, fix that ^
1370         ///
1371         /// See [`Balance`] for additional details on the types of claimable balances which
1372         /// may be returned here and their meanings.
1373         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1374                 let mut res = Vec::new();
1375                 let us = self.inner.lock().unwrap();
1376
1377                 let mut confirmed_txid = us.funding_spend_confirmed;
1378                 let mut pending_commitment_tx_conf_thresh = None;
1379                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1380                         if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1381                                 Some((event.txid, event.confirmation_threshold()))
1382                         } else { None }
1383                 });
1384                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1385                         debug_assert!(us.funding_spend_confirmed.is_none(),
1386                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1387                         confirmed_txid = Some(txid);
1388                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1389                 }
1390
1391                 macro_rules! walk_htlcs {
1392                         ($holder_commitment: expr, $htlc_iter: expr) => {
1393                                 for htlc in $htlc_iter {
1394                                         if let Some(htlc_input_idx) = htlc.transaction_output_index {
1395                                                 if let Some(conf_thresh) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1396                                                         if let OnchainEvent::MaturingOutput { descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) } = &event.event {
1397                                                                 if descriptor.outpoint.index as u32 == htlc_input_idx { Some(event.confirmation_threshold()) } else { None }
1398                                                         } else { None }
1399                                                 }) {
1400                                                         debug_assert!($holder_commitment);
1401                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1402                                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1403                                                                 confirmation_height: conf_thresh,
1404                                                         });
1405                                                 } else if us.htlcs_resolved_on_chain.iter().any(|v| v.input_idx == htlc_input_idx) {
1406                                                         // Funding transaction spends should be fully confirmed by the time any
1407                                                         // HTLC transactions are resolved, unless we're talking about a holder
1408                                                         // commitment tx, whose resolution is delayed until the CSV timeout is
1409                                                         // reached, even though HTLCs may be resolved after only
1410                                                         // ANTI_REORG_DELAY confirmations.
1411                                                         debug_assert!($holder_commitment || us.funding_spend_confirmed.is_some());
1412                                                 } else if htlc.offered == $holder_commitment {
1413                                                         // If the payment was outbound, check if there's an HTLCUpdate
1414                                                         // indicating we have spent this HTLC with a timeout, claiming it back
1415                                                         // and awaiting confirmations on it.
1416                                                         let htlc_update_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1417                                                                 if let OnchainEvent::HTLCUpdate { input_idx: Some(input_idx), .. } = event.event {
1418                                                                         if input_idx == htlc_input_idx { Some(event.confirmation_threshold()) } else { None }
1419                                                                 } else { None }
1420                                                         });
1421                                                         if let Some(conf_thresh) = htlc_update_pending {
1422                                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1423                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1424                                                                         confirmation_height: conf_thresh,
1425                                                                 });
1426                                                         } else {
1427                                                                 res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1428                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1429                                                                         claimable_height: htlc.cltv_expiry,
1430                                                                 });
1431                                                         }
1432                                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1433                                                         // Otherwise (the payment was inbound), only expose it as claimable if
1434                                                         // we know the preimage.
1435                                                         // Note that if there is a pending claim, but it did not use the
1436                                                         // preimage, we lost funds to our counterparty! We will then continue
1437                                                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1438                                                         let htlc_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1439                                                                 if let OnchainEvent::HTLCSpendConfirmation { input_idx, preimage, .. } = event.event {
1440                                                                         if input_idx == htlc_input_idx {
1441                                                                                 Some((event.confirmation_threshold(), preimage.is_some()))
1442                                                                         } else { None }
1443                                                                 } else { None }
1444                                                         });
1445                                                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1446                                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1447                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1448                                                                         confirmation_height: conf_thresh,
1449                                                                 });
1450                                                         } else {
1451                                                                 res.push(Balance::ContentiousClaimable {
1452                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1453                                                                         timeout_height: htlc.cltv_expiry,
1454                                                                 });
1455                                                         }
1456                                                 }
1457                                         }
1458                                 }
1459                         }
1460                 }
1461
1462                 if let Some(txid) = confirmed_txid {
1463                         let mut found_commitment_tx = false;
1464                         if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1465                                 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().map(|(a, _)| a));
1466                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1467                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1468                                                 if let OnchainEvent::MaturingOutput {
1469                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1470                                                 } = &event.event {
1471                                                         Some(descriptor.output.value)
1472                                                 } else { None }
1473                                         }) {
1474                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1475                                                         claimable_amount_satoshis: value,
1476                                                         confirmation_height: conf_thresh,
1477                                                 });
1478                                         } else {
1479                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1480                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1481                                                 // confirmation with the same height or have never met our dust amount.
1482                                         }
1483                                 }
1484                                 found_commitment_tx = true;
1485                         } else if txid == us.current_holder_commitment_tx.txid {
1486                                 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1487                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1488                                         res.push(Balance::ClaimableAwaitingConfirmations {
1489                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1490                                                 confirmation_height: conf_thresh,
1491                                         });
1492                                 }
1493                                 found_commitment_tx = true;
1494                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1495                                 if txid == prev_commitment.txid {
1496                                         walk_htlcs!(true, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1497                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1498                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1499                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1500                                                         confirmation_height: conf_thresh,
1501                                                 });
1502                                         }
1503                                         found_commitment_tx = true;
1504                                 }
1505                         }
1506                         if !found_commitment_tx {
1507                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1508                                         // We blindly assume this is a cooperative close transaction here, and that
1509                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1510                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1511                                         res.push(Balance::ClaimableAwaitingConfirmations {
1512                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1513                                                 confirmation_height: conf_thresh,
1514                                         });
1515                                 }
1516                         }
1517                         // TODO: Add logic to provide claimable balances for counterparty broadcasting revoked
1518                         // outputs.
1519                 } else {
1520                         let mut claimable_inbound_htlc_value_sat = 0;
1521                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1522                                 if htlc.transaction_output_index.is_none() { continue; }
1523                                 if htlc.offered {
1524                                         res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1525                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1526                                                 claimable_height: htlc.cltv_expiry,
1527                                         });
1528                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1529                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1530                                 }
1531                         }
1532                         res.push(Balance::ClaimableOnChannelClose {
1533                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1534                         });
1535                 }
1536
1537                 res
1538         }
1539
1540         /// Gets the set of outbound HTLCs which are pending resolution in this channel.
1541         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1542         pub(crate) fn get_pending_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
1543                 let mut res = HashMap::new();
1544                 let us = self.inner.lock().unwrap();
1545
1546                 macro_rules! walk_htlcs {
1547                         ($holder_commitment: expr, $htlc_iter: expr) => {
1548                                 for (htlc, source) in $htlc_iter {
1549                                         if us.htlcs_resolved_on_chain.iter().any(|v| Some(v.input_idx) == htlc.transaction_output_index) {
1550                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1551                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1552                                                 // would fail.
1553                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1554                                                 // should assert here like we do in `get_claimable_balances`.
1555                                         } else if htlc.offered == $holder_commitment {
1556                                                 // If the payment was outbound, check if there's an HTLCUpdate
1557                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1558                                                 // and awaiting confirmations on it.
1559                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1560                                                         if let OnchainEvent::HTLCUpdate { input_idx: Some(input_idx), .. } = event.event {
1561                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1562                                                                 // before considering it "no longer pending" - this matches when we
1563                                                                 // provide the ChannelManager an HTLC failure event.
1564                                                                 Some(input_idx) == htlc.transaction_output_index &&
1565                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1566                                                         } else if let OnchainEvent::HTLCSpendConfirmation { input_idx, .. } = event.event {
1567                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1568                                                                 // immediately non-pending, matching when we provide ChannelManager
1569                                                                 // the preimage.
1570                                                                 Some(input_idx) == htlc.transaction_output_index
1571                                                         } else { false }
1572                                                 });
1573                                                 if !htlc_update_confd {
1574                                                         res.insert(source.clone(), htlc.clone());
1575                                                 }
1576                                         }
1577                                 }
1578                         }
1579                 }
1580
1581                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1582                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1583                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1584                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1585                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1586                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1587                                         Some(event.txid)
1588                                 } else { None }
1589                         })
1590                 });
1591                 if let Some(txid) = confirmed_txid {
1592                         if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1593                                 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1594                                         if let &Some(ref source) = b {
1595                                                 Some((a, &**source))
1596                                         } else { None }
1597                                 }));
1598                         } else if txid == us.current_holder_commitment_tx.txid {
1599                                 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1600                                         if let Some(source) = c { Some((a, source)) } else { None }
1601                                 }));
1602                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1603                                 if txid == prev_commitment.txid {
1604                                         walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1605                                                 if let Some(source) = c { Some((a, source)) } else { None }
1606                                         }));
1607                                 }
1608                         }
1609                 } else {
1610                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1611                         // closed), just examine the available counterparty commitment transactions. See docs
1612                         // on `fail_unbroadcast_htlcs`, below, for justification.
1613                         macro_rules! walk_counterparty_commitment {
1614                                 ($txid: expr) => {
1615                                         if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1616                                                 for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1617                                                         if let &Some(ref source) = source_option {
1618                                                                 res.insert((**source).clone(), htlc.clone());
1619                                                         }
1620                                                 }
1621                                         }
1622                                 }
1623                         }
1624                         if let Some(ref txid) = us.current_counterparty_commitment_txid {
1625                                 walk_counterparty_commitment!(txid);
1626                         }
1627                         if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1628                                 walk_counterparty_commitment!(txid);
1629                         }
1630                 }
1631
1632                 res
1633         }
1634 }
1635
1636 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1637 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1638 /// after ANTI_REORG_DELAY blocks.
1639 ///
1640 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1641 /// are the commitment transactions which are generated by us. The off-chain state machine in
1642 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1643 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1644 /// included in a remote commitment transaction are failed back if they are not present in the
1645 /// broadcasted commitment transaction.
1646 ///
1647 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1648 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1649 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1650 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1651 macro_rules! fail_unbroadcast_htlcs {
1652         ($self: expr, $commitment_tx_type: expr, $commitment_tx_conf_height: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1653                 macro_rules! check_htlc_fails {
1654                         ($txid: expr, $commitment_tx: expr) => {
1655                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1656                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1657                                                 if let &Some(ref source) = source_option {
1658                                                         // Check if the HTLC is present in the commitment transaction that was
1659                                                         // broadcast, but not if it was below the dust limit, which we should
1660                                                         // fail backwards immediately as there is no way for us to learn the
1661                                                         // payment_preimage.
1662                                                         // Note that if the dust limit were allowed to change between
1663                                                         // commitment transactions we'd want to be check whether *any*
1664                                                         // broadcastable commitment transaction has the HTLC in it, but it
1665                                                         // cannot currently change after channel initialization, so we don't
1666                                                         // need to here.
1667                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1668                                                         let mut matched_htlc = false;
1669                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1670                                                                 if broadcast_htlc.transaction_output_index.is_some() && Some(&**source) == *broadcast_source {
1671                                                                         matched_htlc = true;
1672                                                                         break;
1673                                                                 }
1674                                                         }
1675                                                         if matched_htlc { continue; }
1676                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1677                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1678                                                                 match entry.event {
1679                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1680                                                                                 *update_source != **source
1681                                                                         },
1682                                                                         _ => true,
1683                                                                 }
1684                                                         });
1685                                                         let entry = OnchainEventEntry {
1686                                                                 txid: *$txid,
1687                                                                 height: $commitment_tx_conf_height,
1688                                                                 event: OnchainEvent::HTLCUpdate {
1689                                                                         source: (**source).clone(),
1690                                                                         payment_hash: htlc.payment_hash.clone(),
1691                                                                         onchain_value_satoshis: Some(htlc.amount_msat / 1000),
1692                                                                         input_idx: None,
1693                                                                 },
1694                                                         };
1695                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction, waiting for confirmation (at height {})",
1696                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type, entry.confirmation_threshold());
1697                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
1698                                                 }
1699                                         }
1700                                 }
1701                         }
1702                 }
1703                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
1704                         check_htlc_fails!(txid, "current");
1705                 }
1706                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
1707                         check_htlc_fails!(txid, "previous");
1708                 }
1709         } }
1710 }
1711
1712 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1713         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1714         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1715         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1716         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1717                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1718                         return Err("Previous secret did not match new one");
1719                 }
1720
1721                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1722                 // events for now-revoked/fulfilled HTLCs.
1723                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1724                         for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1725                                 *source = None;
1726                         }
1727                 }
1728
1729                 if !self.payment_preimages.is_empty() {
1730                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1731                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1732                         let min_idx = self.get_min_seen_secret();
1733                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1734
1735                         self.payment_preimages.retain(|&k, _| {
1736                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1737                                         if k == htlc.payment_hash {
1738                                                 return true
1739                                         }
1740                                 }
1741                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1742                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1743                                                 if k == htlc.payment_hash {
1744                                                         return true
1745                                                 }
1746                                         }
1747                                 }
1748                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1749                                         if *cn < min_idx {
1750                                                 return true
1751                                         }
1752                                         true
1753                                 } else { false };
1754                                 if contains {
1755                                         counterparty_hash_commitment_number.remove(&k);
1756                                 }
1757                                 false
1758                         });
1759                 }
1760
1761                 Ok(())
1762         }
1763
1764         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1765                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1766                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1767                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1768                 // timeouts)
1769                 for &(ref htlc, _) in &htlc_outputs {
1770                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1771                 }
1772
1773                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1774                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1775                 self.current_counterparty_commitment_txid = Some(txid);
1776                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1777                 self.current_counterparty_commitment_number = commitment_number;
1778                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1779                 match self.their_cur_revocation_points {
1780                         Some(old_points) => {
1781                                 if old_points.0 == commitment_number + 1 {
1782                                         self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1783                                 } else if old_points.0 == commitment_number + 2 {
1784                                         if let Some(old_second_point) = old_points.2 {
1785                                                 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1786                                         } else {
1787                                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1788                                         }
1789                                 } else {
1790                                         self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1791                                 }
1792                         },
1793                         None => {
1794                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1795                         }
1796                 }
1797                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1798                 for htlc in htlc_outputs {
1799                         if htlc.0.transaction_output_index.is_some() {
1800                                 htlcs.push(htlc.0);
1801                         }
1802                 }
1803         }
1804
1805         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1806         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1807         /// is important that any clones of this channel monitor (including remote clones) by kept
1808         /// up-to-date as our holder commitment transaction is updated.
1809         /// Panics if set_on_holder_tx_csv has never been called.
1810         fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), &'static str> {
1811                 // block for Rust 1.34 compat
1812                 let mut new_holder_commitment_tx = {
1813                         let trusted_tx = holder_commitment_tx.trust();
1814                         let txid = trusted_tx.txid();
1815                         let tx_keys = trusted_tx.keys();
1816                         self.current_holder_commitment_number = trusted_tx.commitment_number();
1817                         HolderSignedTx {
1818                                 txid,
1819                                 revocation_key: tx_keys.revocation_key,
1820                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1821                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1822                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1823                                 per_commitment_point: tx_keys.per_commitment_point,
1824                                 htlc_outputs,
1825                                 to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
1826                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1827                         }
1828                 };
1829                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1830                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1831                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1832                 if self.holder_tx_signed {
1833                         return Err("Latest holder commitment signed has already been signed, update is rejected");
1834                 }
1835                 Ok(())
1836         }
1837
1838         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1839         /// commitment_tx_infos which contain the payment hash have been revoked.
1840         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
1841         where B::Target: BroadcasterInterface,
1842                     F::Target: FeeEstimator,
1843                     L::Target: Logger,
1844         {
1845                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1846
1847                 // If the channel is force closed, try to claim the output from this preimage.
1848                 // First check if a counterparty commitment transaction has been broadcasted:
1849                 macro_rules! claim_htlcs {
1850                         ($commitment_number: expr, $txid: expr) => {
1851                                 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1852                                 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1853                         }
1854                 }
1855                 if let Some(txid) = self.current_counterparty_commitment_txid {
1856                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1857                                 claim_htlcs!(*commitment_number, txid);
1858                                 return;
1859                         }
1860                 }
1861                 if let Some(txid) = self.prev_counterparty_commitment_txid {
1862                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1863                                 claim_htlcs!(*commitment_number, txid);
1864                                 return;
1865                         }
1866                 }
1867
1868                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1869                 // claiming the HTLC output from each of the holder commitment transactions.
1870                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1871                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1872                 // holder commitment transactions.
1873                 if self.broadcasted_holder_revokable_script.is_some() {
1874                         // Assume that the broadcasted commitment transaction confirmed in the current best
1875                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
1876                         // transactions.
1877                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
1878                         self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1879                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1880                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
1881                                 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1882                         }
1883                 }
1884         }
1885
1886         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1887                 where B::Target: BroadcasterInterface,
1888                                         L::Target: Logger,
1889         {
1890                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1891                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
1892                         broadcaster.broadcast_transaction(tx);
1893                 }
1894                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
1895         }
1896
1897         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), ()>
1898         where B::Target: BroadcasterInterface,
1899                     F::Target: FeeEstimator,
1900                     L::Target: Logger,
1901         {
1902                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
1903                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
1904                 // ChannelMonitor updates may be applied after force close if we receive a
1905                 // preimage for a broadcasted commitment transaction HTLC output that we'd
1906                 // like to claim on-chain. If this is the case, we no longer have guaranteed
1907                 // access to the monitor's update ID, so we use a sentinel value instead.
1908                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1909                         assert_eq!(updates.updates.len(), 1);
1910                         match updates.updates[0] {
1911                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1912                                 _ => {
1913                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
1914                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
1915                                 },
1916                         }
1917                 } else if self.latest_update_id + 1 != updates.update_id {
1918                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1919                 }
1920                 let mut ret = Ok(());
1921                 for update in updates.updates.iter() {
1922                         match update {
1923                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1924                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1925                                         if self.lockdown_from_offchain { panic!(); }
1926                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone()) {
1927                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
1928                                                 log_error!(logger, "    {}", e);
1929                                                 ret = Err(());
1930                                         }
1931                                 }
1932                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1933                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1934                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1935                                 },
1936                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1937                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1938                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1939                                 },
1940                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1941                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1942                                         if let Err(e) = self.provide_secret(*idx, *secret) {
1943                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
1944                                                 log_error!(logger, "    {}", e);
1945                                                 ret = Err(());
1946                                         }
1947                                 },
1948                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1949                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1950                                         self.lockdown_from_offchain = true;
1951                                         if *should_broadcast {
1952                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1953                                         } else if !self.holder_tx_signed {
1954                                                 log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
1955                                         } else {
1956                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
1957                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
1958                                                 // shouldn't print the scary warning above.
1959                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
1960                                         }
1961                                 },
1962                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
1963                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
1964                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
1965                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
1966                                         }
1967                                 },
1968                         }
1969                 }
1970                 self.latest_update_id = updates.update_id;
1971
1972                 if ret.is_ok() && self.funding_spend_seen {
1973                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
1974                         Err(())
1975                 } else { ret }
1976         }
1977
1978         pub fn get_latest_update_id(&self) -> u64 {
1979                 self.latest_update_id
1980         }
1981
1982         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1983                 &self.funding_info
1984         }
1985
1986         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1987                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1988                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1989                 // its trivial to do, double-check that here.
1990                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1991                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1992                 }
1993                 &self.outputs_to_watch
1994         }
1995
1996         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1997                 let mut ret = Vec::new();
1998                 mem::swap(&mut ret, &mut self.pending_monitor_events);
1999                 ret
2000         }
2001
2002         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2003                 let mut ret = Vec::new();
2004                 mem::swap(&mut ret, &mut self.pending_events);
2005                 ret
2006         }
2007
2008         /// Can only fail if idx is < get_min_seen_secret
2009         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2010                 self.commitment_secrets.get_secret(idx)
2011         }
2012
2013         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2014                 self.commitment_secrets.get_min_seen_secret()
2015         }
2016
2017         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2018                 self.current_counterparty_commitment_number
2019         }
2020
2021         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2022                 self.current_holder_commitment_number
2023         }
2024
2025         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2026         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2027         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2028         /// HTLC-Success/HTLC-Timeout transactions.
2029         /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
2030         /// revoked counterparty commitment tx
2031         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<PackageTemplate>, TransactionOutputs) where L::Target: Logger {
2032                 // Most secp and related errors trying to create keys means we have no hope of constructing
2033                 // a spend transaction...so we return no transactions to broadcast
2034                 let mut claimable_outpoints = Vec::new();
2035                 let mut watch_outputs = Vec::new();
2036
2037                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2038                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2039
2040                 macro_rules! ignore_error {
2041                         ( $thing : expr ) => {
2042                                 match $thing {
2043                                         Ok(a) => a,
2044                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
2045                                 }
2046                         };
2047                 }
2048
2049                 let commitment_number = 0xffffffffffff - ((((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
2050                 if commitment_number >= self.get_min_seen_secret() {
2051                         let secret = self.get_secret(commitment_number).unwrap();
2052                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2053                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2054                         let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
2055                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_commitment_params.counterparty_delayed_payment_base_key));
2056
2057                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2058                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2059
2060                         // First, process non-htlc outputs (to_holder & to_counterparty)
2061                         for (idx, outp) in tx.output.iter().enumerate() {
2062                                 if outp.script_pubkey == revokeable_p2wsh {
2063                                         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);
2064                                         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, true, height);
2065                                         claimable_outpoints.push(justice_package);
2066                                 }
2067                         }
2068
2069                         // Then, try to find revoked htlc outputs
2070                         if let Some(ref per_commitment_data) = per_commitment_option {
2071                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2072                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2073                                                 if transaction_output_index as usize >= tx.output.len() ||
2074                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2075                                                         return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
2076                                                 }
2077                                                 let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), self.onchain_tx_handler.channel_transaction_parameters.opt_anchors.is_some());
2078                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2079                                                 claimable_outpoints.push(justice_package);
2080                                         }
2081                                 }
2082                         }
2083
2084                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2085                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2086                                 // We're definitely a counterparty commitment transaction!
2087                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2088                                 for (idx, outp) in tx.output.iter().enumerate() {
2089                                         watch_outputs.push((idx as u32, outp.clone()));
2090                                 }
2091                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2092
2093                                 fail_unbroadcast_htlcs!(self, "revoked counterparty", height, [].iter().map(|a| *a), logger);
2094                         }
2095                 } else if let Some(per_commitment_data) = per_commitment_option {
2096                         // While this isn't useful yet, there is a potential race where if a counterparty
2097                         // revokes a state at the same time as the commitment transaction for that state is
2098                         // confirmed, and the watchtower receives the block before the user, the user could
2099                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2100                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2101                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2102                         // insert it here.
2103                         for (idx, outp) in tx.output.iter().enumerate() {
2104                                 watch_outputs.push((idx as u32, outp.clone()));
2105                         }
2106                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2107
2108                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2109                         fail_unbroadcast_htlcs!(self, "counterparty", height, per_commitment_data.iter().map(|(a, b)| (a, b.as_ref().map(|b| b.as_ref()))), logger);
2110
2111                         let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
2112                         for req in htlc_claim_reqs {
2113                                 claimable_outpoints.push(req);
2114                         }
2115
2116                 }
2117                 (claimable_outpoints, (commitment_txid, watch_outputs))
2118         }
2119
2120         fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<PackageTemplate> {
2121                 let mut claimable_outpoints = Vec::new();
2122                 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
2123                         if let Some(revocation_points) = self.their_cur_revocation_points {
2124                                 let revocation_point_option =
2125                                         // If the counterparty commitment tx is the latest valid state, use their latest
2126                                         // per-commitment point
2127                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
2128                                         else if let Some(point) = revocation_points.2.as_ref() {
2129                                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2130                                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2131                                                 // them to temporarily have two valid commitment txns from our viewpoint)
2132                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
2133                                         } else { None };
2134                                 if let Some(revocation_point) = revocation_point_option {
2135                                         for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2136                                                 if let Some(transaction_output_index) = htlc.transaction_output_index {
2137                                                         if let Some(transaction) = tx {
2138                                                                 if transaction_output_index as usize >= transaction.output.len() ||
2139                                                                         transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2140                                                                                 return claimable_outpoints; // Corrupted per_commitment_data, fuck this user
2141                                                                         }
2142                                                         }
2143                                                         let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2144                                                         if preimage.is_some() || !htlc.offered {
2145                                                                 let counterparty_htlc_outp = if htlc.offered { PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(*revocation_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, preimage.unwrap(), htlc.clone())) } else { PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(*revocation_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, htlc.clone())) };
2146                                                                 let aggregation = if !htlc.offered { false } else { true };
2147                                                                 let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2148                                                                 claimable_outpoints.push(counterparty_package);
2149                                                         }
2150                                                 }
2151                                         }
2152                                 }
2153                         }
2154                 }
2155                 claimable_outpoints
2156         }
2157
2158         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2159         fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<PackageTemplate>, Option<TransactionOutputs>) where L::Target: Logger {
2160                 let htlc_txid = tx.txid();
2161                 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
2162                         return (Vec::new(), None)
2163                 }
2164
2165                 macro_rules! ignore_error {
2166                         ( $thing : expr ) => {
2167                                 match $thing {
2168                                         Ok(a) => a,
2169                                         Err(_) => return (Vec::new(), None)
2170                                 }
2171                         };
2172                 }
2173
2174                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2175                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2176                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2177
2178                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, 0);
2179                 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, tx.output[0].value, self.counterparty_commitment_params.on_counterparty_tx_csv);
2180                 let justice_package = PackageTemplate::build_package(htlc_txid, 0, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_commitment_params.on_counterparty_tx_csv as u32, true, height);
2181                 let claimable_outpoints = vec!(justice_package);
2182                 let outputs = vec![(0, tx.output[0].clone())];
2183                 (claimable_outpoints, Some((htlc_txid, outputs)))
2184         }
2185
2186         // Returns (1) `PackageTemplate`s that can be given to the OnChainTxHandler, so that the handler can
2187         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2188         // script so we can detect whether a holder transaction has been seen on-chain.
2189         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2190                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2191
2192                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2193                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2194
2195                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2196                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2197                                 let htlc_output = if htlc.offered {
2198                                                 HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
2199                                         } else {
2200                                                 let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2201                                                         preimage.clone()
2202                                                 } else {
2203                                                         // We can't build an HTLC-Success transaction without the preimage
2204                                                         continue;
2205                                                 };
2206                                                 HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
2207                                         };
2208                                 let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
2209                                 claim_requests.push(htlc_package);
2210                         }
2211                 }
2212
2213                 (claim_requests, broadcasted_holder_revokable_script)
2214         }
2215
2216         // Returns holder HTLC outputs to watch and react to in case of spending.
2217         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2218                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2219                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2220                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2221                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2222                         }
2223                 }
2224                 watch_outputs
2225         }
2226
2227         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2228         /// revoked using data in holder_claimable_outpoints.
2229         /// Should not be used if check_spend_revoked_transaction succeeds.
2230         /// Returns None unless the transaction is definitely one of our commitment transactions.
2231         fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> Option<(Vec<PackageTemplate>, TransactionOutputs)> where L::Target: Logger {
2232                 let commitment_txid = tx.txid();
2233                 let mut claim_requests = Vec::new();
2234                 let mut watch_outputs = Vec::new();
2235
2236                 macro_rules! append_onchain_update {
2237                         ($updates: expr, $to_watch: expr) => {
2238                                 claim_requests = $updates.0;
2239                                 self.broadcasted_holder_revokable_script = $updates.1;
2240                                 watch_outputs.append(&mut $to_watch);
2241                         }
2242                 }
2243
2244                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2245                 let mut is_holder_tx = false;
2246
2247                 if self.current_holder_commitment_tx.txid == commitment_txid {
2248                         is_holder_tx = true;
2249                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2250                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2251                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2252                         append_onchain_update!(res, to_watch);
2253                         fail_unbroadcast_htlcs!(self, "latest holder", height, self.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, c)| (a, c.as_ref())), logger);
2254                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2255                         if holder_tx.txid == commitment_txid {
2256                                 is_holder_tx = true;
2257                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2258                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2259                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2260                                 append_onchain_update!(res, to_watch);
2261                                 fail_unbroadcast_htlcs!(self, "previous holder", height, holder_tx.htlc_outputs.iter().map(|(a, _, c)| (a, c.as_ref())), logger);
2262                         }
2263                 }
2264
2265                 if is_holder_tx {
2266                         Some((claim_requests, (commitment_txid, watch_outputs)))
2267                 } else {
2268                         None
2269                 }
2270         }
2271
2272         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2273                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2274                 self.holder_tx_signed = true;
2275                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2276                 let txid = commitment_tx.txid();
2277                 let mut holder_transactions = vec![commitment_tx];
2278                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2279                         if let Some(vout) = htlc.0.transaction_output_index {
2280                                 let preimage = if !htlc.0.offered {
2281                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2282                                                 // We can't build an HTLC-Success transaction without the preimage
2283                                                 continue;
2284                                         }
2285                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2286                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2287                                         // current locktime requirements on-chain. We will broadcast them in
2288                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2289                                         // Note that we add + 1 as transactions are broadcastable when they can be
2290                                         // confirmed in the next block.
2291                                         continue;
2292                                 } else { None };
2293                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2294                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2295                                         holder_transactions.push(htlc_tx);
2296                                 }
2297                         }
2298                 }
2299                 // 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.
2300                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2301                 holder_transactions
2302         }
2303
2304         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2305         /// Note that this includes possibly-locktimed-in-the-future transactions!
2306         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2307                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2308                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2309                 let txid = commitment_tx.txid();
2310                 let mut holder_transactions = vec![commitment_tx];
2311                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2312                         if let Some(vout) = htlc.0.transaction_output_index {
2313                                 let preimage = if !htlc.0.offered {
2314                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2315                                                 // We can't build an HTLC-Success transaction without the preimage
2316                                                 continue;
2317                                         }
2318                                 } else { None };
2319                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2320                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2321                                         holder_transactions.push(htlc_tx);
2322                                 }
2323                         }
2324                 }
2325                 holder_transactions
2326         }
2327
2328         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>
2329                 where B::Target: BroadcasterInterface,
2330                       F::Target: FeeEstimator,
2331                                         L::Target: Logger,
2332         {
2333                 let block_hash = header.block_hash();
2334                 self.best_block = BestBlock::new(block_hash, height);
2335
2336                 self.transactions_confirmed(header, txdata, height, broadcaster, fee_estimator, logger)
2337         }
2338
2339         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2340                 &mut self,
2341                 header: &BlockHeader,
2342                 height: u32,
2343                 broadcaster: B,
2344                 fee_estimator: F,
2345                 logger: L,
2346         ) -> Vec<TransactionOutputs>
2347         where
2348                 B::Target: BroadcasterInterface,
2349                 F::Target: FeeEstimator,
2350                 L::Target: Logger,
2351         {
2352                 let block_hash = header.block_hash();
2353
2354                 if height > self.best_block.height() {
2355                         self.best_block = BestBlock::new(block_hash, height);
2356                         self.block_confirmed(height, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2357                 } else if block_hash != self.best_block.block_hash() {
2358                         self.best_block = BestBlock::new(block_hash, height);
2359                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2360                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2361                         Vec::new()
2362                 } else { Vec::new() }
2363         }
2364
2365         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2366                 &mut self,
2367                 header: &BlockHeader,
2368                 txdata: &TransactionData,
2369                 height: u32,
2370                 broadcaster: B,
2371                 fee_estimator: F,
2372                 logger: L,
2373         ) -> Vec<TransactionOutputs>
2374         where
2375                 B::Target: BroadcasterInterface,
2376                 F::Target: FeeEstimator,
2377                 L::Target: Logger,
2378         {
2379                 let txn_matched = self.filter_block(txdata);
2380                 for tx in &txn_matched {
2381                         let mut output_val = 0;
2382                         for out in tx.output.iter() {
2383                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2384                                 output_val += out.value;
2385                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2386                         }
2387                 }
2388
2389                 let block_hash = header.block_hash();
2390
2391                 let mut watch_outputs = Vec::new();
2392                 let mut claimable_outpoints = Vec::new();
2393                 for tx in &txn_matched {
2394                         if tx.input.len() == 1 {
2395                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2396                                 // commitment transactions and HTLC transactions will all only ever have one input,
2397                                 // which is an easy way to filter out any potential non-matching txn for lazy
2398                                 // filters.
2399                                 let prevout = &tx.input[0].previous_output;
2400                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2401                                         let mut balance_spendable_csv = None;
2402                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
2403                                                 log_bytes!(self.funding_info.0.to_channel_id()), tx.txid());
2404                                         self.funding_spend_seen = true;
2405                                         if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
2406                                                 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
2407                                                 if !new_outputs.1.is_empty() {
2408                                                         watch_outputs.push(new_outputs);
2409                                                 }
2410                                                 claimable_outpoints.append(&mut new_outpoints);
2411                                                 if new_outpoints.is_empty() {
2412                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &logger) {
2413                                                                 if !new_outputs.1.is_empty() {
2414                                                                         watch_outputs.push(new_outputs);
2415                                                                 }
2416                                                                 claimable_outpoints.append(&mut new_outpoints);
2417                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
2418                                                         }
2419                                                 }
2420                                         }
2421                                         let txid = tx.txid();
2422                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2423                                                 txid,
2424                                                 height: height,
2425                                                 event: OnchainEvent::FundingSpendConfirmation {
2426                                                         on_local_output_csv: balance_spendable_csv,
2427                                                 },
2428                                         });
2429                                 } else {
2430                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2431                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2432                                                 claimable_outpoints.append(&mut new_outpoints);
2433                                                 if let Some(new_outputs) = new_outputs_option {
2434                                                         watch_outputs.push(new_outputs);
2435                                                 }
2436                                         }
2437                                 }
2438                         }
2439                         // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2440                         // can also be resolved in a few other ways which can have more than one output. Thus,
2441                         // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2442                         self.is_resolving_htlc_output(&tx, height, &logger);
2443
2444                         self.is_paying_spendable_output(&tx, height, &logger);
2445                 }
2446
2447                 if height > self.best_block.height() {
2448                         self.best_block = BestBlock::new(block_hash, height);
2449                 }
2450
2451                 self.block_confirmed(height, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
2452         }
2453
2454         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
2455         /// `self.best_block` before calling if a new best blockchain tip is available. More
2456         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
2457         /// complexity especially in `OnchainTx::update_claims_view`.
2458         ///
2459         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
2460         /// confirmed at, even if it is not the current best height.
2461         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
2462                 &mut self,
2463                 conf_height: u32,
2464                 txn_matched: Vec<&Transaction>,
2465                 mut watch_outputs: Vec<TransactionOutputs>,
2466                 mut claimable_outpoints: Vec<PackageTemplate>,
2467                 broadcaster: &B,
2468                 fee_estimator: &F,
2469                 logger: &L,
2470         ) -> Vec<TransactionOutputs>
2471         where
2472                 B::Target: BroadcasterInterface,
2473                 F::Target: FeeEstimator,
2474                 L::Target: Logger,
2475         {
2476                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
2477                 debug_assert!(self.best_block.height() >= conf_height);
2478
2479                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
2480                 if should_broadcast {
2481                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
2482                         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(), false, self.best_block.height());
2483                         claimable_outpoints.push(commitment_package);
2484                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2485                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2486                         self.holder_tx_signed = true;
2487                         // Because we're broadcasting a commitment transaction, we should construct the package
2488                         // assuming it gets confirmed in the next block. Sadly, we have code which considers
2489                         // "not yet confirmed" things as discardable, so we cannot do that here.
2490                         let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2491                         let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2492                         if !new_outputs.is_empty() {
2493                                 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2494                         }
2495                         claimable_outpoints.append(&mut new_outpoints);
2496                 }
2497
2498                 // Find which on-chain events have reached their confirmation threshold.
2499                 let onchain_events_awaiting_threshold_conf =
2500                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
2501                 let mut onchain_events_reaching_threshold_conf = Vec::new();
2502                 for entry in onchain_events_awaiting_threshold_conf {
2503                         if entry.has_reached_confirmation_threshold(&self.best_block) {
2504                                 onchain_events_reaching_threshold_conf.push(entry);
2505                         } else {
2506                                 self.onchain_events_awaiting_threshold_conf.push(entry);
2507                         }
2508                 }
2509
2510                 // Used to check for duplicate HTLC resolutions.
2511                 #[cfg(debug_assertions)]
2512                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
2513                         .iter()
2514                         .filter_map(|entry| match &entry.event {
2515                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
2516                                 _ => None,
2517                         })
2518                         .collect();
2519                 #[cfg(debug_assertions)]
2520                 let mut matured_htlcs = Vec::new();
2521
2522                 // Produce actionable events from on-chain events having reached their threshold.
2523                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
2524                         match entry.event {
2525                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, onchain_value_satoshis, input_idx } => {
2526                                         // Check for duplicate HTLC resolutions.
2527                                         #[cfg(debug_assertions)]
2528                                         {
2529                                                 debug_assert!(
2530                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
2531                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
2532                                                          call either transaction_unconfirmed for the conflicting transaction \
2533                                                          or block_disconnected for a block containing it.");
2534                                                 debug_assert!(
2535                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
2536                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
2537                                                          call either transaction_unconfirmed for the conflicting transaction \
2538                                                          or block_disconnected for a block containing it.");
2539                                                 matured_htlcs.push(source.clone());
2540                                         }
2541
2542                                         log_debug!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!(payment_hash.0));
2543                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2544                                                 payment_hash,
2545                                                 payment_preimage: None,
2546                                                 source: source.clone(),
2547                                                 onchain_value_satoshis,
2548                                         }));
2549                                         if let Some(idx) = input_idx {
2550                                                 self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { input_idx: idx, payment_preimage: None });
2551                                         }
2552                                 },
2553                                 OnchainEvent::MaturingOutput { descriptor } => {
2554                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2555                                         self.pending_events.push(Event::SpendableOutputs {
2556                                                 outputs: vec![descriptor]
2557                                         });
2558                                 },
2559                                 OnchainEvent::HTLCSpendConfirmation { input_idx, preimage, .. } => {
2560                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { input_idx, payment_preimage: preimage });
2561                                 },
2562                                 OnchainEvent::FundingSpendConfirmation { .. } => {
2563                                         self.funding_spend_confirmed = Some(entry.txid);
2564                                 },
2565                         }
2566                 }
2567
2568                 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
2569
2570                 // Determine new outputs to watch by comparing against previously known outputs to watch,
2571                 // updating the latter in the process.
2572                 watch_outputs.retain(|&(ref txid, ref txouts)| {
2573                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2574                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2575                 });
2576                 #[cfg(test)]
2577                 {
2578                         // If we see a transaction for which we registered outputs previously,
2579                         // make sure the registered scriptpubkey at the expected index match
2580                         // the actual transaction output one. We failed this case before #653.
2581                         for tx in &txn_matched {
2582                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2583                                         for idx_and_script in outputs.iter() {
2584                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
2585                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2586                                         }
2587                                 }
2588                         }
2589                 }
2590                 watch_outputs
2591         }
2592
2593         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2594                 where B::Target: BroadcasterInterface,
2595                       F::Target: FeeEstimator,
2596                       L::Target: Logger,
2597         {
2598                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
2599
2600                 //We may discard:
2601                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2602                 //- maturing spendable output has transaction paying us has been disconnected
2603                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
2604
2605                 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2606
2607                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
2608         }
2609
2610         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
2611                 &mut self,
2612                 txid: &Txid,
2613                 broadcaster: B,
2614                 fee_estimator: F,
2615                 logger: L,
2616         ) where
2617                 B::Target: BroadcasterInterface,
2618                 F::Target: FeeEstimator,
2619                 L::Target: Logger,
2620         {
2621                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.txid != *txid);
2622                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
2623         }
2624
2625         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2626         /// transactions thereof.
2627         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2628                 let mut matched_txn = HashSet::new();
2629                 txdata.iter().filter(|&&(_, tx)| {
2630                         let mut matches = self.spends_watched_output(tx);
2631                         for input in tx.input.iter() {
2632                                 if matches { break; }
2633                                 if matched_txn.contains(&input.previous_output.txid) {
2634                                         matches = true;
2635                                 }
2636                         }
2637                         if matches {
2638                                 matched_txn.insert(tx.txid());
2639                         }
2640                         matches
2641                 }).map(|(_, tx)| *tx).collect()
2642         }
2643
2644         /// Checks if a given transaction spends any watched outputs.
2645         fn spends_watched_output(&self, tx: &Transaction) -> bool {
2646                 for input in tx.input.iter() {
2647                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2648                                 for (idx, _script_pubkey) in outputs.iter() {
2649                                         if *idx == input.previous_output.vout {
2650                                                 #[cfg(test)]
2651                                                 {
2652                                                         // If the expected script is a known type, check that the witness
2653                                                         // appears to be spending the correct type (ie that the match would
2654                                                         // actually succeed in BIP 158/159-style filters).
2655                                                         if _script_pubkey.is_v0_p2wsh() {
2656                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2657                                                         } else if _script_pubkey.is_v0_p2wpkh() {
2658                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2659                                                         } else { panic!(); }
2660                                                 }
2661                                                 return true;
2662                                         }
2663                                 }
2664                         }
2665                 }
2666
2667                 false
2668         }
2669
2670         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
2671                 // We need to consider all HTLCs which are:
2672                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
2673                 //    transactions and we'd end up in a race, or
2674                 //  * are in our latest holder commitment transaction, as this is the thing we will
2675                 //    broadcast if we go on-chain.
2676                 // Note that we consider HTLCs which were below dust threshold here - while they don't
2677                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2678                 // to the source, and if we don't fail the channel we will have to ensure that the next
2679                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2680                 // easier to just fail the channel as this case should be rare enough anyway.
2681                 let height = self.best_block.height();
2682                 macro_rules! scan_commitment {
2683                         ($htlcs: expr, $holder_tx: expr) => {
2684                                 for ref htlc in $htlcs {
2685                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2686                                         // chain with enough room to claim the HTLC without our counterparty being able to
2687                                         // time out the HTLC first.
2688                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2689                                         // concern is being able to claim the corresponding inbound HTLC (on another
2690                                         // channel) before it expires. In fact, we don't even really care if our
2691                                         // counterparty here claims such an outbound HTLC after it expired as long as we
2692                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2693                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2694                                         // we give ourselves a few blocks of headroom after expiration before going
2695                                         // on-chain for an expired HTLC.
2696                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2697                                         // from us until we've reached the point where we go on-chain with the
2698                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2699                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2700                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2701                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
2702                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2703                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2704                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2705                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2706                                         //  The final, above, condition is checked for statically in channelmanager
2707                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
2708                                         let htlc_outbound = $holder_tx == htlc.offered;
2709                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2710                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2711                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2712                                                 return true;
2713                                         }
2714                                 }
2715                         }
2716                 }
2717
2718                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2719
2720                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2721                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2722                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2723                         }
2724                 }
2725                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2726                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2727                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2728                         }
2729                 }
2730
2731                 false
2732         }
2733
2734         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2735         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2736         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2737                 'outer_loop: for input in &tx.input {
2738                         let mut payment_data = None;
2739                         let witness_items = input.witness.len();
2740                         let htlctype = input.witness.last().map(|w| w.len()).and_then(HTLCType::scriptlen_to_htlctype);
2741                         let prev_last_witness_len = input.witness.second_to_last().map(|w| w.len()).unwrap_or(0);
2742                         let revocation_sig_claim = (witness_items == 3 && htlctype == Some(HTLCType::OfferedHTLC) && prev_last_witness_len == 33)
2743                                 || (witness_items == 3 && htlctype == Some(HTLCType::AcceptedHTLC) && prev_last_witness_len == 33);
2744                         let accepted_preimage_claim = witness_items == 5 && htlctype == Some(HTLCType::AcceptedHTLC);
2745                         #[cfg(not(fuzzing))]
2746                         let accepted_timeout_claim = witness_items == 3 && htlctype == Some(HTLCType::AcceptedHTLC) && !revocation_sig_claim;
2747                         let offered_preimage_claim = witness_items == 3 && htlctype == Some(HTLCType::OfferedHTLC) && !revocation_sig_claim;
2748                         #[cfg(not(fuzzing))]
2749                         let offered_timeout_claim = witness_items == 5 && htlctype == Some(HTLCType::OfferedHTLC);
2750
2751                         let mut payment_preimage = PaymentPreimage([0; 32]);
2752                         if accepted_preimage_claim {
2753                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
2754                         } else if offered_preimage_claim {
2755                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
2756                         }
2757
2758                         macro_rules! log_claim {
2759                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2760                                         let outbound_htlc = $holder_tx == $htlc.offered;
2761                                         // HTLCs must either be claimed by a matching script type or through the
2762                                         // revocation path:
2763                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2764                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
2765                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2766                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
2767                                         // Further, only exactly one of the possible spend paths should have been
2768                                         // matched by any HTLC spend:
2769                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2770                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
2771                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
2772                                                          revocation_sig_claim as u8, 1);
2773                                         if ($holder_tx && revocation_sig_claim) ||
2774                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2775                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2776                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2777                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2778                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2779                                         } else {
2780                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2781                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2782                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2783                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2784                                         }
2785                                 }
2786                         }
2787
2788                         macro_rules! check_htlc_valid_counterparty {
2789                                 ($counterparty_txid: expr, $htlc_output: expr) => {
2790                                         if let Some(txid) = $counterparty_txid {
2791                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2792                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2793                                                                 if let &Some(ref source) = pending_source {
2794                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2795                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
2796                                                                         break;
2797                                                                 }
2798                                                         }
2799                                                 }
2800                                         }
2801                                 }
2802                         }
2803
2804                         macro_rules! scan_commitment {
2805                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2806                                         for (ref htlc_output, source_option) in $htlcs {
2807                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2808                                                         if let Some(ref source) = source_option {
2809                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
2810                                                                 // We have a resolution of an HTLC either from one of our latest
2811                                                                 // holder commitment transactions or an unrevoked counterparty commitment
2812                                                                 // transaction. This implies we either learned a preimage, the HTLC
2813                                                                 // has timed out, or we screwed up. In any case, we should now
2814                                                                 // resolve the source HTLC with the original sender.
2815                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
2816                                                         } else if !$holder_tx {
2817                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2818                                                                 if payment_data.is_none() {
2819                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2820                                                                 }
2821                                                         }
2822                                                         if payment_data.is_none() {
2823                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
2824                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
2825                                                                 if !outbound_htlc || revocation_sig_claim {
2826                                                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2827                                                                                 txid: tx.txid(), height,
2828                                                                                 event: OnchainEvent::HTLCSpendConfirmation {
2829                                                                                         input_idx: input.previous_output.vout,
2830                                                                                         preimage: if accepted_preimage_claim || offered_preimage_claim {
2831                                                                                                 Some(payment_preimage) } else { None },
2832                                                                                         // If this is a payment to us (!outbound_htlc, above),
2833                                                                                         // wait for the CSV delay before dropping the HTLC from
2834                                                                                         // claimable balance if the claim was an HTLC-Success
2835                                                                                         // transaction.
2836                                                                                         on_to_local_output_csv: if accepted_preimage_claim {
2837                                                                                                 Some(self.on_holder_tx_csv) } else { None },
2838                                                                                 },
2839                                                                         });
2840                                                                 } else {
2841                                                                         // Outbound claims should always have payment_data, unless
2842                                                                         // we've already failed the HTLC as the commitment transaction
2843                                                                         // which was broadcasted was revoked. In that case, we should
2844                                                                         // spend the HTLC output here immediately, and expose that fact
2845                                                                         // as a Balance, something which we do not yet do.
2846                                                                         // TODO: Track the above as claimable!
2847                                                                 }
2848                                                                 continue 'outer_loop;
2849                                                         }
2850                                                 }
2851                                         }
2852                                 }
2853                         }
2854
2855                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2856                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2857                                         "our latest holder commitment tx", true);
2858                         }
2859                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2860                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2861                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2862                                                 "our previous holder commitment tx", true);
2863                                 }
2864                         }
2865                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2866                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2867                                         "counterparty commitment tx", false);
2868                         }
2869
2870                         // Check that scan_commitment, above, decided there is some source worth relaying an
2871                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2872                         if let Some((source, payment_hash, amount_msat)) = payment_data {
2873                                 if accepted_preimage_claim {
2874                                         if !self.pending_monitor_events.iter().any(
2875                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2876                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2877                                                         txid: tx.txid(),
2878                                                         height,
2879                                                         event: OnchainEvent::HTLCSpendConfirmation {
2880                                                                 input_idx: input.previous_output.vout,
2881                                                                 preimage: Some(payment_preimage),
2882                                                                 on_to_local_output_csv: None,
2883                                                         },
2884                                                 });
2885                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2886                                                         source,
2887                                                         payment_preimage: Some(payment_preimage),
2888                                                         payment_hash,
2889                                                         onchain_value_satoshis: Some(amount_msat / 1000),
2890                                                 }));
2891                                         }
2892                                 } else if offered_preimage_claim {
2893                                         if !self.pending_monitor_events.iter().any(
2894                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2895                                                         upd.source == source
2896                                                 } else { false }) {
2897                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2898                                                         txid: tx.txid(),
2899                                                         height,
2900                                                         event: OnchainEvent::HTLCSpendConfirmation {
2901                                                                 input_idx: input.previous_output.vout,
2902                                                                 preimage: Some(payment_preimage),
2903                                                                 on_to_local_output_csv: None,
2904                                                         },
2905                                                 });
2906                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2907                                                         source,
2908                                                         payment_preimage: Some(payment_preimage),
2909                                                         payment_hash,
2910                                                         onchain_value_satoshis: Some(amount_msat / 1000),
2911                                                 }));
2912                                         }
2913                                 } else {
2914                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
2915                                                 if entry.height != height { return true; }
2916                                                 match entry.event {
2917                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
2918                                                                 *htlc_source != source
2919                                                         },
2920                                                         _ => true,
2921                                                 }
2922                                         });
2923                                         let entry = OnchainEventEntry {
2924                                                 txid: tx.txid(),
2925                                                 height,
2926                                                 event: OnchainEvent::HTLCUpdate {
2927                                                         source, payment_hash,
2928                                                         onchain_value_satoshis: Some(amount_msat / 1000),
2929                                                         input_idx: Some(input.previous_output.vout),
2930                                                 },
2931                                         };
2932                                         log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
2933                                         self.onchain_events_awaiting_threshold_conf.push(entry);
2934                                 }
2935                         }
2936                 }
2937         }
2938
2939         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2940         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2941                 let mut spendable_output = None;
2942                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2943                         if i > ::core::u16::MAX as usize {
2944                                 // While it is possible that an output exists on chain which is greater than the
2945                                 // 2^16th output in a given transaction, this is only possible if the output is not
2946                                 // in a lightning transaction and was instead placed there by some third party who
2947                                 // wishes to give us money for no reason.
2948                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
2949                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2950                                 // scripts are not longer than one byte in length and because they are inherently
2951                                 // non-standard due to their size.
2952                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
2953                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
2954                                 // nearly a full block with garbage just to hit this case.
2955                                 continue;
2956                         }
2957                         if outp.script_pubkey == self.destination_script {
2958                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
2959                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2960                                         output: outp.clone(),
2961                                 });
2962                                 break;
2963                         }
2964                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2965                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2966                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2967                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2968                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
2969                                                 to_self_delay: self.on_holder_tx_csv,
2970                                                 output: outp.clone(),
2971                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2972                                                 channel_keys_id: self.channel_keys_id,
2973                                                 channel_value_satoshis: self.channel_value_satoshis,
2974                                         }));
2975                                         break;
2976                                 }
2977                         }
2978                         if self.counterparty_payment_script == outp.script_pubkey {
2979                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2980                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2981                                         output: outp.clone(),
2982                                         channel_keys_id: self.channel_keys_id,
2983                                         channel_value_satoshis: self.channel_value_satoshis,
2984                                 }));
2985                                 break;
2986                         }
2987                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
2988                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2989                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2990                                         output: outp.clone(),
2991                                 });
2992                                 break;
2993                         }
2994                 }
2995                 if let Some(spendable_output) = spendable_output {
2996                         let entry = OnchainEventEntry {
2997                                 txid: tx.txid(),
2998                                 height: height,
2999                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3000                         };
3001                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3002                         self.onchain_events_awaiting_threshold_conf.push(entry);
3003                 }
3004         }
3005 }
3006
3007 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3008 where
3009         T::Target: BroadcasterInterface,
3010         F::Target: FeeEstimator,
3011         L::Target: Logger,
3012 {
3013         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3014                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3015         }
3016
3017         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3018                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3019         }
3020 }
3021
3022 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3023 where
3024         T::Target: BroadcasterInterface,
3025         F::Target: FeeEstimator,
3026         L::Target: Logger,
3027 {
3028         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3029                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3030         }
3031
3032         fn transaction_unconfirmed(&self, txid: &Txid) {
3033                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3034         }
3035
3036         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3037                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3038         }
3039
3040         fn get_relevant_txids(&self) -> Vec<Txid> {
3041                 self.0.get_relevant_txids()
3042         }
3043 }
3044
3045 const MAX_ALLOC_SIZE: usize = 64*1024;
3046
3047 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
3048                 for (BlockHash, ChannelMonitor<Signer>) {
3049         fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
3050                 macro_rules! unwrap_obj {
3051                         ($key: expr) => {
3052                                 match $key {
3053                                         Ok(res) => res,
3054                                         Err(_) => return Err(DecodeError::InvalidValue),
3055                                 }
3056                         }
3057                 }
3058
3059                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3060
3061                 let latest_update_id: u64 = Readable::read(reader)?;
3062                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3063
3064                 let destination_script = Readable::read(reader)?;
3065                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3066                         0 => {
3067                                 let revokable_address = Readable::read(reader)?;
3068                                 let per_commitment_point = Readable::read(reader)?;
3069                                 let revokable_script = Readable::read(reader)?;
3070                                 Some((revokable_address, per_commitment_point, revokable_script))
3071                         },
3072                         1 => { None },
3073                         _ => return Err(DecodeError::InvalidValue),
3074                 };
3075                 let counterparty_payment_script = Readable::read(reader)?;
3076                 let shutdown_script = {
3077                         let script = <Script as Readable>::read(reader)?;
3078                         if script.is_empty() { None } else { Some(script) }
3079                 };
3080
3081                 let channel_keys_id = Readable::read(reader)?;
3082                 let holder_revocation_basepoint = Readable::read(reader)?;
3083                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3084                 // barely-init'd ChannelMonitors that we can't do anything with.
3085                 let outpoint = OutPoint {
3086                         txid: Readable::read(reader)?,
3087                         index: Readable::read(reader)?,
3088                 };
3089                 let funding_info = (outpoint, Readable::read(reader)?);
3090                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3091                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3092
3093                 let counterparty_commitment_params = Readable::read(reader)?;
3094                 let funding_redeemscript = Readable::read(reader)?;
3095                 let channel_value_satoshis = Readable::read(reader)?;
3096
3097                 let their_cur_revocation_points = {
3098                         let first_idx = <U48 as Readable>::read(reader)?.0;
3099                         if first_idx == 0 {
3100                                 None
3101                         } else {
3102                                 let first_point = Readable::read(reader)?;
3103                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3104                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3105                                         Some((first_idx, first_point, None))
3106                                 } else {
3107                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3108                                 }
3109                         }
3110                 };
3111
3112                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3113
3114                 let commitment_secrets = Readable::read(reader)?;
3115
3116                 macro_rules! read_htlc_in_commitment {
3117                         () => {
3118                                 {
3119                                         let offered: bool = Readable::read(reader)?;
3120                                         let amount_msat: u64 = Readable::read(reader)?;
3121                                         let cltv_expiry: u32 = Readable::read(reader)?;
3122                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3123                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3124
3125                                         HTLCOutputInCommitment {
3126                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3127                                         }
3128                                 }
3129                         }
3130                 }
3131
3132                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3133                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3134                 for _ in 0..counterparty_claimable_outpoints_len {
3135                         let txid: Txid = Readable::read(reader)?;
3136                         let htlcs_count: u64 = Readable::read(reader)?;
3137                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3138                         for _ in 0..htlcs_count {
3139                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3140                         }
3141                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3142                                 return Err(DecodeError::InvalidValue);
3143                         }
3144                 }
3145
3146                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3147                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3148                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3149                         let txid: Txid = Readable::read(reader)?;
3150                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3151                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3152                                 return Err(DecodeError::InvalidValue);
3153                         }
3154                 }
3155
3156                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3157                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3158                 for _ in 0..counterparty_hash_commitment_number_len {
3159                         let payment_hash: PaymentHash = Readable::read(reader)?;
3160                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3161                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3162                                 return Err(DecodeError::InvalidValue);
3163                         }
3164                 }
3165
3166                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3167                         match <u8 as Readable>::read(reader)? {
3168                                 0 => None,
3169                                 1 => {
3170                                         Some(Readable::read(reader)?)
3171                                 },
3172                                 _ => return Err(DecodeError::InvalidValue),
3173                         };
3174                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3175
3176                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3177                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3178
3179                 let payment_preimages_len: u64 = Readable::read(reader)?;
3180                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3181                 for _ in 0..payment_preimages_len {
3182                         let preimage: PaymentPreimage = Readable::read(reader)?;
3183                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3184                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3185                                 return Err(DecodeError::InvalidValue);
3186                         }
3187                 }
3188
3189                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3190                 let mut pending_monitor_events = Some(
3191                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3192                 for _ in 0..pending_monitor_events_len {
3193                         let ev = match <u8 as Readable>::read(reader)? {
3194                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3195                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3196                                 _ => return Err(DecodeError::InvalidValue)
3197                         };
3198                         pending_monitor_events.as_mut().unwrap().push(ev);
3199                 }
3200
3201                 let pending_events_len: u64 = Readable::read(reader)?;
3202                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3203                 for _ in 0..pending_events_len {
3204                         if let Some(event) = MaybeReadable::read(reader)? {
3205                                 pending_events.push(event);
3206                         }
3207                 }
3208
3209                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3210
3211                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3212                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3213                 for _ in 0..waiting_threshold_conf_len {
3214                         if let Some(val) = MaybeReadable::read(reader)? {
3215                                 onchain_events_awaiting_threshold_conf.push(val);
3216                         }
3217                 }
3218
3219                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3220                 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>>())));
3221                 for _ in 0..outputs_to_watch_len {
3222                         let txid = Readable::read(reader)?;
3223                         let outputs_len: u64 = Readable::read(reader)?;
3224                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3225                         for _ in 0..outputs_len {
3226                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3227                         }
3228                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3229                                 return Err(DecodeError::InvalidValue);
3230                         }
3231                 }
3232                 let onchain_tx_handler: OnchainTxHandler<Signer> = ReadableArgs::read(reader, keys_manager)?;
3233
3234                 let lockdown_from_offchain = Readable::read(reader)?;
3235                 let holder_tx_signed = Readable::read(reader)?;
3236
3237                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3238                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3239                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3240                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3241                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3242                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3243                                 return Err(DecodeError::InvalidValue);
3244                         }
3245                 }
3246
3247                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3248                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3249                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3250                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3251                         return Err(DecodeError::InvalidValue);
3252                 }
3253
3254                 let mut funding_spend_confirmed = None;
3255                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3256                 let mut funding_spend_seen = Some(false);
3257                 read_tlv_fields!(reader, {
3258                         (1, funding_spend_confirmed, option),
3259                         (3, htlcs_resolved_on_chain, vec_type),
3260                         (5, pending_monitor_events, vec_type),
3261                         (7, funding_spend_seen, option),
3262                 });
3263
3264                 let mut secp_ctx = Secp256k1::new();
3265                 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
3266
3267                 Ok((best_block.block_hash(), ChannelMonitor {
3268                         inner: Mutex::new(ChannelMonitorImpl {
3269                                 latest_update_id,
3270                                 commitment_transaction_number_obscure_factor,
3271
3272                                 destination_script,
3273                                 broadcasted_holder_revokable_script,
3274                                 counterparty_payment_script,
3275                                 shutdown_script,
3276
3277                                 channel_keys_id,
3278                                 holder_revocation_basepoint,
3279                                 funding_info,
3280                                 current_counterparty_commitment_txid,
3281                                 prev_counterparty_commitment_txid,
3282
3283                                 counterparty_commitment_params,
3284                                 funding_redeemscript,
3285                                 channel_value_satoshis,
3286                                 their_cur_revocation_points,
3287
3288                                 on_holder_tx_csv,
3289
3290                                 commitment_secrets,
3291                                 counterparty_claimable_outpoints,
3292                                 counterparty_commitment_txn_on_chain,
3293                                 counterparty_hash_commitment_number,
3294
3295                                 prev_holder_signed_commitment_tx,
3296                                 current_holder_commitment_tx,
3297                                 current_counterparty_commitment_number,
3298                                 current_holder_commitment_number,
3299
3300                                 payment_preimages,
3301                                 pending_monitor_events: pending_monitor_events.unwrap(),
3302                                 pending_events,
3303
3304                                 onchain_events_awaiting_threshold_conf,
3305                                 outputs_to_watch,
3306
3307                                 onchain_tx_handler,
3308
3309                                 lockdown_from_offchain,
3310                                 holder_tx_signed,
3311                                 funding_spend_seen: funding_spend_seen.unwrap(),
3312                                 funding_spend_confirmed,
3313                                 htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3314
3315                                 best_block,
3316
3317                                 secp_ctx,
3318                         }),
3319                 }))
3320         }
3321 }
3322
3323 #[cfg(test)]
3324 mod tests {
3325         use bitcoin::blockdata::block::BlockHeader;
3326         use bitcoin::blockdata::script::{Script, Builder};
3327         use bitcoin::blockdata::opcodes;
3328         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
3329         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3330         use bitcoin::util::sighash;
3331         use bitcoin::hashes::Hash;
3332         use bitcoin::hashes::sha256::Hash as Sha256;
3333         use bitcoin::hashes::hex::FromHex;
3334         use bitcoin::hash_types::{BlockHash, Txid};
3335         use bitcoin::network::constants::Network;
3336         use bitcoin::secp256k1::{SecretKey,PublicKey};
3337         use bitcoin::secp256k1::Secp256k1;
3338
3339         use hex;
3340
3341         use super::ChannelMonitorUpdateStep;
3342         use ::{check_added_monitors, check_closed_broadcast, check_closed_event, check_spends, get_local_commitment_txn, get_monitor, get_route_and_payment_hash, unwrap_send_err};
3343         use chain::{BestBlock, Confirm};
3344         use chain::channelmonitor::ChannelMonitor;
3345         use chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
3346         use chain::transaction::OutPoint;
3347         use chain::keysinterface::InMemorySigner;
3348         use ln::{PaymentPreimage, PaymentHash};
3349         use ln::chan_utils;
3350         use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
3351         use ln::channelmanager::PaymentSendFailure;
3352         use ln::features::InitFeatures;
3353         use ln::functional_test_utils::*;
3354         use ln::script::ShutdownScript;
3355         use util::errors::APIError;
3356         use util::events::{ClosureReason, MessageSendEventsProvider};
3357         use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
3358         use util::ser::{ReadableArgs, Writeable};
3359         use sync::{Arc, Mutex};
3360         use io;
3361         use bitcoin::Witness;
3362         use prelude::*;
3363
3364         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
3365                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
3366                 // confirmed. This would allow a race condition where we could receive a payment (including
3367                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
3368                 // long as the ChannelMonitor receives the block first, the full commitment update dance
3369                 // occurs after the block is connected, and before the ChannelManager receives the block.
3370                 // Obviously this is an incredibly contrived race given the counterparty would be risking
3371                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
3372                 // potential ChannelMonitor states simpler to reason about.
3373                 //
3374                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
3375                 // updates is handled correctly in such conditions.
3376                 let chanmon_cfgs = create_chanmon_cfgs(3);
3377                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
3378                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
3379                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
3380                 let channel = create_announced_chan_between_nodes(
3381                         &nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
3382                 create_announced_chan_between_nodes(
3383                         &nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
3384
3385                 // Rebalance somewhat
3386                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
3387
3388                 // First route two payments for testing at the end
3389                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
3390                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
3391
3392                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
3393                 assert_eq!(local_txn.len(), 1);
3394                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
3395                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
3396                 check_spends!(remote_txn[1], remote_txn[0]);
3397                 check_spends!(remote_txn[2], remote_txn[0]);
3398                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
3399
3400                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
3401                 // channel is now closed, but the ChannelManager doesn't know that yet.
3402                 let new_header = BlockHeader {
3403                         version: 2, time: 0, bits: 0, nonce: 0,
3404                         prev_blockhash: nodes[0].best_block_info().0,
3405                         merkle_root: Default::default() };
3406                 let conf_height = nodes[0].best_block_info().1 + 1;
3407                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
3408                         &[(0, broadcast_tx)], conf_height);
3409
3410                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
3411                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
3412                                                 &nodes[1].keys_manager.backing).unwrap();
3413
3414                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
3415                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
3416                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
3417                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret)),
3418                         true, APIError::ChannelUnavailable { ref err },
3419                         assert!(err.contains("ChannelMonitor storage failure")));
3420                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
3421                 check_closed_broadcast!(nodes[1], true);
3422                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
3423
3424                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
3425                 // and provides the claim preimages for the two pending HTLCs. The first update generates
3426                 // an error, but the point of this test is to ensure the later updates are still applied.
3427                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
3428                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
3429                 assert_eq!(replay_update.updates.len(), 1);
3430                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
3431                 } else { panic!(); }
3432                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
3433                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
3434
3435                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
3436                 assert!(
3437                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &&chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
3438                         .is_err());
3439                 // Even though we error'd on the first update, we should still have generated an HTLC claim
3440                 // transaction
3441                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
3442                 assert!(txn_broadcasted.len() >= 2);
3443                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
3444                         assert_eq!(tx.input.len(), 1);
3445                         tx.input[0].previous_output.txid == broadcast_tx.txid()
3446                 }).collect::<Vec<_>>();
3447                 assert_eq!(htlc_txn.len(), 2);
3448                 check_spends!(htlc_txn[0], broadcast_tx);
3449                 check_spends!(htlc_txn[1], broadcast_tx);
3450         }
3451         #[test]
3452         fn test_funding_spend_refuses_updates() {
3453                 do_test_funding_spend_refuses_updates(true);
3454                 do_test_funding_spend_refuses_updates(false);
3455         }
3456
3457         #[test]
3458         fn test_prune_preimages() {
3459                 let secp_ctx = Secp256k1::new();
3460                 let logger = Arc::new(TestLogger::new());
3461                 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
3462                 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: Mutex::new(253) });
3463
3464                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3465                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3466
3467                 let mut preimages = Vec::new();
3468                 {
3469                         for i in 0..20 {
3470                                 let preimage = PaymentPreimage([i; 32]);
3471                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3472                                 preimages.push((preimage, hash));
3473                         }
3474                 }
3475
3476                 macro_rules! preimages_slice_to_htlc_outputs {
3477                         ($preimages_slice: expr) => {
3478                                 {
3479                                         let mut res = Vec::new();
3480                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
3481                                                 res.push((HTLCOutputInCommitment {
3482                                                         offered: true,
3483                                                         amount_msat: 0,
3484                                                         cltv_expiry: 0,
3485                                                         payment_hash: preimage.1.clone(),
3486                                                         transaction_output_index: Some(idx as u32),
3487                                                 }, None));
3488                                         }
3489                                         res
3490                                 }
3491                         }
3492                 }
3493                 macro_rules! preimages_to_holder_htlcs {
3494                         ($preimages_slice: expr) => {
3495                                 {
3496                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
3497                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
3498                                         res
3499                                 }
3500                         }
3501                 }
3502
3503                 macro_rules! test_preimages_exist {
3504                         ($preimages_slice: expr, $monitor: expr) => {
3505                                 for preimage in $preimages_slice {
3506                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
3507                                 }
3508                         }
3509                 }
3510
3511                 let keys = InMemorySigner::new(
3512                         &secp_ctx,
3513                         SecretKey::from_slice(&[41; 32]).unwrap(),
3514                         SecretKey::from_slice(&[41; 32]).unwrap(),
3515                         SecretKey::from_slice(&[41; 32]).unwrap(),
3516                         SecretKey::from_slice(&[41; 32]).unwrap(),
3517                         SecretKey::from_slice(&[41; 32]).unwrap(),
3518                         SecretKey::from_slice(&[41; 32]).unwrap(),
3519                         [41; 32],
3520                         0,
3521                         [0; 32]
3522                 );
3523
3524                 let counterparty_pubkeys = ChannelPublicKeys {
3525                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
3526                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
3527                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
3528                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
3529                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
3530                 };
3531                 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
3532                 let channel_parameters = ChannelTransactionParameters {
3533                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
3534                         holder_selected_contest_delay: 66,
3535                         is_outbound_from_holder: true,
3536                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
3537                                 pubkeys: counterparty_pubkeys,
3538                                 selected_contest_delay: 67,
3539                         }),
3540                         funding_outpoint: Some(funding_outpoint),
3541                         opt_anchors: None,
3542                 };
3543                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
3544                 // old state.
3545                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3546                 let best_block = BestBlock::from_genesis(Network::Testnet);
3547                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
3548                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
3549                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
3550                                                   &channel_parameters,
3551                                                   Script::new(), 46, 0,
3552                                                   HolderCommitmentTransaction::dummy(), best_block);
3553
3554                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
3555                 let dummy_txid = dummy_tx.txid();
3556                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
3557                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
3558                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
3559                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
3560                 for &(ref preimage, ref hash) in preimages.iter() {
3561                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
3562                 }
3563
3564                 // Now provide a secret, pruning preimages 10-15
3565                 let mut secret = [0; 32];
3566                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
3567                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
3568                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
3569                 test_preimages_exist!(&preimages[0..10], monitor);
3570                 test_preimages_exist!(&preimages[15..20], monitor);
3571
3572                 // Now provide a further secret, pruning preimages 15-17
3573                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
3574                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
3575                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
3576                 test_preimages_exist!(&preimages[0..10], monitor);
3577                 test_preimages_exist!(&preimages[17..20], monitor);
3578
3579                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
3580                 // previous commitment tx's preimages too
3581                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
3582                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
3583                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
3584                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
3585                 test_preimages_exist!(&preimages[0..10], monitor);
3586                 test_preimages_exist!(&preimages[18..20], monitor);
3587
3588                 // But if we do it again, we'll prune 5-10
3589                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
3590                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
3591                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
3592                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
3593                 test_preimages_exist!(&preimages[0..5], monitor);
3594         }
3595
3596         #[test]
3597         fn test_claim_txn_weight_computation() {
3598                 // We test Claim txn weight, knowing that we want expected weigth and
3599                 // not actual case to avoid sigs and time-lock delays hell variances.
3600
3601                 let secp_ctx = Secp256k1::new();
3602                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
3603                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
3604
3605                 macro_rules! sign_input {
3606                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
3607                                 let htlc = HTLCOutputInCommitment {
3608                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
3609                                         amount_msat: 0,
3610                                         cltv_expiry: 2 << 16,
3611                                         payment_hash: PaymentHash([1; 32]),
3612                                         transaction_output_index: Some($idx as u32),
3613                                 };
3614                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
3615                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
3616                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
3617                                 let mut ser_sig = sig.serialize_der().to_vec();
3618                                 ser_sig.push(EcdsaSighashType::All as u8);
3619                                 $sum_actual_sigs += ser_sig.len();
3620                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
3621                                 witness.push(ser_sig);
3622                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
3623                                         witness.push(vec!(1));
3624                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
3625                                         witness.push(pubkey.clone().serialize().to_vec());
3626                                 } else if *$weight == weight_received_htlc($opt_anchors) {
3627                                         witness.push(vec![0]);
3628                                 } else {
3629                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
3630                                 }
3631                                 witness.push(redeem_script.into_bytes());
3632                                 let witness = witness.to_vec();
3633                                 println!("witness[0] {}", witness[0].len());
3634                                 println!("witness[1] {}", witness[1].len());
3635                                 println!("witness[2] {}", witness[2].len());
3636                         }
3637                 }
3638
3639                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
3640                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
3641
3642                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
3643                 for &opt_anchors in [false, true].iter() {
3644                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3645                         let mut sum_actual_sigs = 0;
3646                         for i in 0..4 {
3647                                 claim_tx.input.push(TxIn {
3648                                         previous_output: BitcoinOutPoint {
3649                                                 txid,
3650                                                 vout: i,
3651                                         },
3652                                         script_sig: Script::new(),
3653                                         sequence: 0xfffffffd,
3654                                         witness: Witness::new(),
3655                                 });
3656                         }
3657                         claim_tx.output.push(TxOut {
3658                                 script_pubkey: script_pubkey.clone(),
3659                                 value: 0,
3660                         });
3661                         let base_weight = claim_tx.weight();
3662                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, weight_revoked_offered_htlc(opt_anchors), weight_revoked_offered_htlc(opt_anchors), weight_revoked_received_htlc(opt_anchors)];
3663                         let mut inputs_total_weight = 2; // count segwit flags
3664                         {
3665                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3666                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3667                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3668                                         inputs_total_weight += inp;
3669                                 }
3670                         }
3671                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3672                 }
3673
3674                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3675                 for &opt_anchors in [false, true].iter() {
3676                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3677                         let mut sum_actual_sigs = 0;
3678                         for i in 0..4 {
3679                                 claim_tx.input.push(TxIn {
3680                                         previous_output: BitcoinOutPoint {
3681                                                 txid,
3682                                                 vout: i,
3683                                         },
3684                                         script_sig: Script::new(),
3685                                         sequence: 0xfffffffd,
3686                                         witness: Witness::new(),
3687                                 });
3688                         }
3689                         claim_tx.output.push(TxOut {
3690                                 script_pubkey: script_pubkey.clone(),
3691                                 value: 0,
3692                         });
3693                         let base_weight = claim_tx.weight();
3694                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
3695                         let mut inputs_total_weight = 2; // count segwit flags
3696                         {
3697                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3698                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3699                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3700                                         inputs_total_weight += inp;
3701                                 }
3702                         }
3703                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3704                 }
3705
3706                 // Justice tx with 1 revoked HTLC-Success tx output
3707                 for &opt_anchors in [false, true].iter() {
3708                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3709                         let mut sum_actual_sigs = 0;
3710                         claim_tx.input.push(TxIn {
3711                                 previous_output: BitcoinOutPoint {
3712                                         txid,
3713                                         vout: 0,
3714                                 },
3715                                 script_sig: Script::new(),
3716                                 sequence: 0xfffffffd,
3717                                 witness: Witness::new(),
3718                         });
3719                         claim_tx.output.push(TxOut {
3720                                 script_pubkey: script_pubkey.clone(),
3721                                 value: 0,
3722                         });
3723                         let base_weight = claim_tx.weight();
3724                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
3725                         let mut inputs_total_weight = 2; // count segwit flags
3726                         {
3727                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3728                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3729                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3730                                         inputs_total_weight += inp;
3731                                 }
3732                         }
3733                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
3734                 }
3735         }
3736
3737         // Further testing is done in the ChannelManager integration tests.
3738 }