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[rust-lightning] / lightning / src / chain / channelmonitor.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
11 //! here.
12 //!
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
16 //!
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
22
23 use bitcoin::blockdata::block::BlockHeader;
24 use bitcoin::blockdata::transaction::{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, LowerBoundedFeeEstimator};
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) htlc_value_satoshis: Option<u64>,
170 }
171 impl_writeable_tlv_based!(HTLCUpdate, {
172         (0, payment_hash, required),
173         (1, htlc_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                 htlc_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                 commitment_tx_output_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                 commitment_tx_output_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, htlc_value_satoshis, option),
427                 (2, payment_hash, required),
428                 (3, commitment_tx_output_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, commitment_tx_output_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_per_commitment_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_per_commitment_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         commitment_tx_output_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, commitment_tx_output_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 per-commitment points
623         their_cur_per_commitment_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         /// The set of payment hashes from inbound payments for which we know the preimage. Payment
659         /// preimages that are not included in any unrevoked local commitment transaction or unrevoked
660         /// remote commitment transactions are automatically removed when commitment transactions are
661         /// revoked.
662         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
663
664         // Note that `MonitorEvent`s MUST NOT be generated during update processing, only generated
665         // during chain data processing. This prevents a race in `ChainMonitor::update_channel` (and
666         // presumably user implementations thereof as well) where we update the in-memory channel
667         // object, then before the persistence finishes (as it's all under a read-lock), we return
668         // pending events to the user or to the relevant `ChannelManager`. Then, on reload, we'll have
669         // the pre-event state here, but have processed the event in the `ChannelManager`.
670         // Note that because the `event_lock` in `ChainMonitor` is only taken in
671         // block/transaction-connected events and *not* during block/transaction-disconnected events,
672         // we further MUST NOT generate events during block/transaction-disconnection.
673         pending_monitor_events: Vec<MonitorEvent>,
674
675         pending_events: Vec<Event>,
676
677         // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
678         // which to take actions once they reach enough confirmations. Each entry includes the
679         // transaction's id and the height when the transaction was confirmed on chain.
680         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
681
682         // If we get serialized out and re-read, we need to make sure that the chain monitoring
683         // interface knows about the TXOs that we want to be notified of spends of. We could probably
684         // be smart and derive them from the above storage fields, but its much simpler and more
685         // Obviously Correct (tm) if we just keep track of them explicitly.
686         outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
687
688         #[cfg(test)]
689         pub onchain_tx_handler: OnchainTxHandler<Signer>,
690         #[cfg(not(test))]
691         onchain_tx_handler: OnchainTxHandler<Signer>,
692
693         // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
694         // channel has been force-closed. After this is set, no further holder commitment transaction
695         // updates may occur, and we panic!() if one is provided.
696         lockdown_from_offchain: bool,
697
698         // Set once we've signed a holder commitment transaction and handed it over to our
699         // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
700         // may occur, and we fail any such monitor updates.
701         //
702         // In case of update rejection due to a locally already signed commitment transaction, we
703         // nevertheless store update content to track in case of concurrent broadcast by another
704         // remote monitor out-of-order with regards to the block view.
705         holder_tx_signed: bool,
706
707         // If a spend of the funding output is seen, we set this to true and reject any further
708         // updates. This prevents any further changes in the offchain state no matter the order
709         // of block connection between ChannelMonitors and the ChannelManager.
710         funding_spend_seen: bool,
711
712         funding_spend_confirmed: Option<Txid>,
713         /// The set of HTLCs which have been either claimed or failed on chain and have reached
714         /// the requisite confirmations on the claim/fail transaction (either ANTI_REORG_DELAY or the
715         /// spending CSV for revocable outputs).
716         htlcs_resolved_on_chain: Vec<IrrevocablyResolvedHTLC>,
717
718         // We simply modify best_block in Channel's block_connected so that serialization is
719         // consistent but hopefully the users' copy handles block_connected in a consistent way.
720         // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
721         // their best_block from its state and not based on updated copies that didn't run through
722         // the full block_connected).
723         best_block: BestBlock,
724
725         /// The node_id of our counterparty
726         counterparty_node_id: Option<PublicKey>,
727
728         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
729 }
730
731 /// Transaction outputs to watch for on-chain spends.
732 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
733
734 #[cfg(any(test, fuzzing, feature = "_test_utils"))]
735 /// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
736 /// object
737 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
738         fn eq(&self, other: &Self) -> bool {
739                 let inner = self.inner.lock().unwrap();
740                 let other = other.inner.lock().unwrap();
741                 inner.eq(&other)
742         }
743 }
744
745 #[cfg(any(test, fuzzing, feature = "_test_utils"))]
746 /// Used only in testing and fuzzing to check serialization roundtrips don't change the underlying
747 /// object
748 impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
749         fn eq(&self, other: &Self) -> bool {
750                 if self.latest_update_id != other.latest_update_id ||
751                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
752                         self.destination_script != other.destination_script ||
753                         self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
754                         self.counterparty_payment_script != other.counterparty_payment_script ||
755                         self.channel_keys_id != other.channel_keys_id ||
756                         self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
757                         self.funding_info != other.funding_info ||
758                         self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
759                         self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
760                         self.counterparty_commitment_params != other.counterparty_commitment_params ||
761                         self.funding_redeemscript != other.funding_redeemscript ||
762                         self.channel_value_satoshis != other.channel_value_satoshis ||
763                         self.their_cur_per_commitment_points != other.their_cur_per_commitment_points ||
764                         self.on_holder_tx_csv != other.on_holder_tx_csv ||
765                         self.commitment_secrets != other.commitment_secrets ||
766                         self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
767                         self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
768                         self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
769                         self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
770                         self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
771                         self.current_holder_commitment_number != other.current_holder_commitment_number ||
772                         self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
773                         self.payment_preimages != other.payment_preimages ||
774                         self.pending_monitor_events != other.pending_monitor_events ||
775                         self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
776                         self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
777                         self.outputs_to_watch != other.outputs_to_watch ||
778                         self.lockdown_from_offchain != other.lockdown_from_offchain ||
779                         self.holder_tx_signed != other.holder_tx_signed ||
780                         self.funding_spend_seen != other.funding_spend_seen ||
781                         self.funding_spend_confirmed != other.funding_spend_confirmed ||
782                         self.htlcs_resolved_on_chain != other.htlcs_resolved_on_chain
783                 {
784                         false
785                 } else {
786                         true
787                 }
788         }
789 }
790
791 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
792         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
793                 self.inner.lock().unwrap().write(writer)
794         }
795 }
796
797 // These are also used for ChannelMonitorUpdate, above.
798 const SERIALIZATION_VERSION: u8 = 1;
799 const MIN_SERIALIZATION_VERSION: u8 = 1;
800
801 impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
802         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
803                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
804
805                 self.latest_update_id.write(writer)?;
806
807                 // Set in initial Channel-object creation, so should always be set by now:
808                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
809
810                 self.destination_script.write(writer)?;
811                 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
812                         writer.write_all(&[0; 1])?;
813                         broadcasted_holder_revokable_script.0.write(writer)?;
814                         broadcasted_holder_revokable_script.1.write(writer)?;
815                         broadcasted_holder_revokable_script.2.write(writer)?;
816                 } else {
817                         writer.write_all(&[1; 1])?;
818                 }
819
820                 self.counterparty_payment_script.write(writer)?;
821                 match &self.shutdown_script {
822                         Some(script) => script.write(writer)?,
823                         None => Script::new().write(writer)?,
824                 }
825
826                 self.channel_keys_id.write(writer)?;
827                 self.holder_revocation_basepoint.write(writer)?;
828                 writer.write_all(&self.funding_info.0.txid[..])?;
829                 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
830                 self.funding_info.1.write(writer)?;
831                 self.current_counterparty_commitment_txid.write(writer)?;
832                 self.prev_counterparty_commitment_txid.write(writer)?;
833
834                 self.counterparty_commitment_params.write(writer)?;
835                 self.funding_redeemscript.write(writer)?;
836                 self.channel_value_satoshis.write(writer)?;
837
838                 match self.their_cur_per_commitment_points {
839                         Some((idx, pubkey, second_option)) => {
840                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
841                                 writer.write_all(&pubkey.serialize())?;
842                                 match second_option {
843                                         Some(second_pubkey) => {
844                                                 writer.write_all(&second_pubkey.serialize())?;
845                                         },
846                                         None => {
847                                                 writer.write_all(&[0; 33])?;
848                                         },
849                                 }
850                         },
851                         None => {
852                                 writer.write_all(&byte_utils::be48_to_array(0))?;
853                         },
854                 }
855
856                 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
857
858                 self.commitment_secrets.write(writer)?;
859
860                 macro_rules! serialize_htlc_in_commitment {
861                         ($htlc_output: expr) => {
862                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
863                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
864                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
865                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
866                                 $htlc_output.transaction_output_index.write(writer)?;
867                         }
868                 }
869
870                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
871                 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
872                         writer.write_all(&txid[..])?;
873                         writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
874                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
875                                 debug_assert!(htlc_source.is_none() || Some(**txid) == self.current_counterparty_commitment_txid
876                                                 || Some(**txid) == self.prev_counterparty_commitment_txid,
877                                         "HTLC Sources for all revoked commitment transactions should be none!");
878                                 serialize_htlc_in_commitment!(htlc_output);
879                                 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
880                         }
881                 }
882
883                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
884                 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
885                         writer.write_all(&txid[..])?;
886                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
887                 }
888
889                 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
890                 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
891                         writer.write_all(&payment_hash.0[..])?;
892                         writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
893                 }
894
895                 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
896                         writer.write_all(&[1; 1])?;
897                         prev_holder_tx.write(writer)?;
898                 } else {
899                         writer.write_all(&[0; 1])?;
900                 }
901
902                 self.current_holder_commitment_tx.write(writer)?;
903
904                 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
905                 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
906
907                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
908                 for payment_preimage in self.payment_preimages.values() {
909                         writer.write_all(&payment_preimage.0[..])?;
910                 }
911
912                 writer.write_all(&(self.pending_monitor_events.iter().filter(|ev| match ev {
913                         MonitorEvent::HTLCEvent(_) => true,
914                         MonitorEvent::CommitmentTxConfirmed(_) => true,
915                         _ => false,
916                 }).count() as u64).to_be_bytes())?;
917                 for event in self.pending_monitor_events.iter() {
918                         match event {
919                                 MonitorEvent::HTLCEvent(upd) => {
920                                         0u8.write(writer)?;
921                                         upd.write(writer)?;
922                                 },
923                                 MonitorEvent::CommitmentTxConfirmed(_) => 1u8.write(writer)?,
924                                 _ => {}, // Covered in the TLV writes below
925                         }
926                 }
927
928                 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
929                 for event in self.pending_events.iter() {
930                         event.write(writer)?;
931                 }
932
933                 self.best_block.block_hash().write(writer)?;
934                 writer.write_all(&byte_utils::be32_to_array(self.best_block.height()))?;
935
936                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
937                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
938                         entry.write(writer)?;
939                 }
940
941                 (self.outputs_to_watch.len() as u64).write(writer)?;
942                 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
943                         txid.write(writer)?;
944                         (idx_scripts.len() as u64).write(writer)?;
945                         for (idx, script) in idx_scripts.iter() {
946                                 idx.write(writer)?;
947                                 script.write(writer)?;
948                         }
949                 }
950                 self.onchain_tx_handler.write(writer)?;
951
952                 self.lockdown_from_offchain.write(writer)?;
953                 self.holder_tx_signed.write(writer)?;
954
955                 write_tlv_fields!(writer, {
956                         (1, self.funding_spend_confirmed, option),
957                         (3, self.htlcs_resolved_on_chain, vec_type),
958                         (5, self.pending_monitor_events, vec_type),
959                         (7, self.funding_spend_seen, required),
960                         (9, self.counterparty_node_id, option),
961                 });
962
963                 Ok(())
964         }
965 }
966
967 impl<Signer: Sign> ChannelMonitor<Signer> {
968         pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
969                           on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
970                           channel_parameters: &ChannelTransactionParameters,
971                           funding_redeemscript: Script, channel_value_satoshis: u64,
972                           commitment_transaction_number_obscure_factor: u64,
973                           initial_holder_commitment_tx: HolderCommitmentTransaction,
974                           best_block: BestBlock, counterparty_node_id: PublicKey) -> ChannelMonitor<Signer> {
975
976                 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
977                 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
978                 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
979
980                 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
981                 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
982                 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
983                 let counterparty_commitment_params = CounterpartyCommitmentParameters { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv };
984
985                 let channel_keys_id = keys.channel_keys_id();
986                 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
987
988                 // block for Rust 1.34 compat
989                 let (holder_commitment_tx, current_holder_commitment_number) = {
990                         let trusted_tx = initial_holder_commitment_tx.trust();
991                         let txid = trusted_tx.txid();
992
993                         let tx_keys = trusted_tx.keys();
994                         let holder_commitment_tx = HolderSignedTx {
995                                 txid,
996                                 revocation_key: tx_keys.revocation_key,
997                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
998                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
999                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1000                                 per_commitment_point: tx_keys.per_commitment_point,
1001                                 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
1002                                 to_self_value_sat: initial_holder_commitment_tx.to_broadcaster_value_sat(),
1003                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1004                         };
1005                         (holder_commitment_tx, trusted_tx.commitment_number())
1006                 };
1007
1008                 let onchain_tx_handler =
1009                         OnchainTxHandler::new(destination_script.clone(), keys,
1010                         channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
1011
1012                 let mut outputs_to_watch = HashMap::new();
1013                 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
1014
1015                 ChannelMonitor {
1016                         inner: Mutex::new(ChannelMonitorImpl {
1017                                 latest_update_id: 0,
1018                                 commitment_transaction_number_obscure_factor,
1019
1020                                 destination_script: destination_script.clone(),
1021                                 broadcasted_holder_revokable_script: None,
1022                                 counterparty_payment_script,
1023                                 shutdown_script,
1024
1025                                 channel_keys_id,
1026                                 holder_revocation_basepoint,
1027                                 funding_info,
1028                                 current_counterparty_commitment_txid: None,
1029                                 prev_counterparty_commitment_txid: None,
1030
1031                                 counterparty_commitment_params,
1032                                 funding_redeemscript,
1033                                 channel_value_satoshis,
1034                                 their_cur_per_commitment_points: None,
1035
1036                                 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
1037
1038                                 commitment_secrets: CounterpartyCommitmentSecrets::new(),
1039                                 counterparty_claimable_outpoints: HashMap::new(),
1040                                 counterparty_commitment_txn_on_chain: HashMap::new(),
1041                                 counterparty_hash_commitment_number: HashMap::new(),
1042
1043                                 prev_holder_signed_commitment_tx: None,
1044                                 current_holder_commitment_tx: holder_commitment_tx,
1045                                 current_counterparty_commitment_number: 1 << 48,
1046                                 current_holder_commitment_number,
1047
1048                                 payment_preimages: HashMap::new(),
1049                                 pending_monitor_events: Vec::new(),
1050                                 pending_events: Vec::new(),
1051
1052                                 onchain_events_awaiting_threshold_conf: Vec::new(),
1053                                 outputs_to_watch,
1054
1055                                 onchain_tx_handler,
1056
1057                                 lockdown_from_offchain: false,
1058                                 holder_tx_signed: false,
1059                                 funding_spend_seen: false,
1060                                 funding_spend_confirmed: None,
1061                                 htlcs_resolved_on_chain: Vec::new(),
1062
1063                                 best_block,
1064                                 counterparty_node_id: Some(counterparty_node_id),
1065
1066                                 secp_ctx,
1067                         }),
1068                 }
1069         }
1070
1071         #[cfg(test)]
1072         fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1073                 self.inner.lock().unwrap().provide_secret(idx, secret)
1074         }
1075
1076         /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
1077         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
1078         /// possibly future revocation/preimage information) to claim outputs where possible.
1079         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
1080         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
1081                 &self,
1082                 txid: Txid,
1083                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
1084                 commitment_number: u64,
1085                 their_per_commitment_point: PublicKey,
1086                 logger: &L,
1087         ) where L::Target: Logger {
1088                 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
1089                         txid, htlc_outputs, commitment_number, their_per_commitment_point, logger)
1090         }
1091
1092         #[cfg(test)]
1093         fn provide_latest_holder_commitment_tx(
1094                 &self, holder_commitment_tx: HolderCommitmentTransaction,
1095                 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
1096         ) -> Result<(), ()> {
1097                 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(holder_commitment_tx, htlc_outputs).map_err(|_| ())
1098         }
1099
1100         /// This is used to provide payment preimage(s) out-of-band during startup without updating the
1101         /// off-chain state with a new commitment transaction.
1102         pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1103                 &self,
1104                 payment_hash: &PaymentHash,
1105                 payment_preimage: &PaymentPreimage,
1106                 broadcaster: &B,
1107                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1108                 logger: &L,
1109         ) where
1110                 B::Target: BroadcasterInterface,
1111                 F::Target: FeeEstimator,
1112                 L::Target: Logger,
1113         {
1114                 self.inner.lock().unwrap().provide_payment_preimage(
1115                         payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
1116         }
1117
1118         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
1119                 &self,
1120                 broadcaster: &B,
1121                 logger: &L,
1122         ) where
1123                 B::Target: BroadcasterInterface,
1124                 L::Target: Logger,
1125         {
1126                 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
1127         }
1128
1129         /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
1130         /// itself.
1131         ///
1132         /// panics if the given update is not the next update by update_id.
1133         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
1134                 &self,
1135                 updates: &ChannelMonitorUpdate,
1136                 broadcaster: &B,
1137                 fee_estimator: &F,
1138                 logger: &L,
1139         ) -> Result<(), ()>
1140         where
1141                 B::Target: BroadcasterInterface,
1142                 F::Target: FeeEstimator,
1143                 L::Target: Logger,
1144         {
1145                 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
1146         }
1147
1148         /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
1149         /// ChannelMonitor.
1150         pub fn get_latest_update_id(&self) -> u64 {
1151                 self.inner.lock().unwrap().get_latest_update_id()
1152         }
1153
1154         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
1155         pub fn get_funding_txo(&self) -> (OutPoint, Script) {
1156                 self.inner.lock().unwrap().get_funding_txo().clone()
1157         }
1158
1159         /// Gets a list of txids, with their output scripts (in the order they appear in the
1160         /// transaction), which we must learn about spends of via block_connected().
1161         pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
1162                 self.inner.lock().unwrap().get_outputs_to_watch()
1163                         .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
1164         }
1165
1166         /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
1167         /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
1168         /// have been registered.
1169         pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1170                 let lock = self.inner.lock().unwrap();
1171                 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1172                 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1173                         for (index, script_pubkey) in outputs.iter() {
1174                                 assert!(*index <= u16::max_value() as u32);
1175                                 filter.register_output(WatchedOutput {
1176                                         block_hash: None,
1177                                         outpoint: OutPoint { txid: *txid, index: *index as u16 },
1178                                         script_pubkey: script_pubkey.clone(),
1179                                 });
1180                         }
1181                 }
1182         }
1183
1184         /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1185         /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1186         pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1187                 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1188         }
1189
1190         /// Gets the list of pending events which were generated by previous actions, clearing the list
1191         /// in the process.
1192         ///
1193         /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1194         /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1195         /// no internal locking in ChannelMonitors.
1196         pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1197                 self.inner.lock().unwrap().get_and_clear_pending_events()
1198         }
1199
1200         pub(crate) fn get_min_seen_secret(&self) -> u64 {
1201                 self.inner.lock().unwrap().get_min_seen_secret()
1202         }
1203
1204         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1205                 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1206         }
1207
1208         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1209                 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1210         }
1211
1212         /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1213         /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1214         /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1215         /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1216         /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1217         /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1218         /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1219         /// out-of-band the other node operator to coordinate with him if option is available to you.
1220         /// In any-case, choice is up to the user.
1221         pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1222         where L::Target: Logger {
1223                 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1224         }
1225
1226         /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1227         /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1228         /// revoked commitment transaction.
1229         #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1230         pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1231         where L::Target: Logger {
1232                 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1233         }
1234
1235         /// Processes transactions in a newly connected block, which may result in any of the following:
1236         /// - update the monitor's state against resolved HTLCs
1237         /// - punish the counterparty in the case of seeing a revoked commitment transaction
1238         /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1239         /// - detect settled outputs for later spending
1240         /// - schedule and bump any in-flight claims
1241         ///
1242         /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1243         /// [`get_outputs_to_watch`].
1244         ///
1245         /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1246         pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1247                 &self,
1248                 header: &BlockHeader,
1249                 txdata: &TransactionData,
1250                 height: u32,
1251                 broadcaster: B,
1252                 fee_estimator: F,
1253                 logger: L,
1254         ) -> Vec<TransactionOutputs>
1255         where
1256                 B::Target: BroadcasterInterface,
1257                 F::Target: FeeEstimator,
1258                 L::Target: Logger,
1259         {
1260                 self.inner.lock().unwrap().block_connected(
1261                         header, txdata, height, broadcaster, fee_estimator, logger)
1262         }
1263
1264         /// Determines if the disconnected block contained any transactions of interest and updates
1265         /// appropriately.
1266         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1267                 &self,
1268                 header: &BlockHeader,
1269                 height: u32,
1270                 broadcaster: B,
1271                 fee_estimator: F,
1272                 logger: L,
1273         ) where
1274                 B::Target: BroadcasterInterface,
1275                 F::Target: FeeEstimator,
1276                 L::Target: Logger,
1277         {
1278                 self.inner.lock().unwrap().block_disconnected(
1279                         header, height, broadcaster, fee_estimator, logger)
1280         }
1281
1282         /// Processes transactions confirmed in a block with the given header and height, returning new
1283         /// outputs to watch. See [`block_connected`] for details.
1284         ///
1285         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1286         /// blocks. See [`chain::Confirm`] for calling expectations.
1287         ///
1288         /// [`block_connected`]: Self::block_connected
1289         pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1290                 &self,
1291                 header: &BlockHeader,
1292                 txdata: &TransactionData,
1293                 height: u32,
1294                 broadcaster: B,
1295                 fee_estimator: F,
1296                 logger: L,
1297         ) -> Vec<TransactionOutputs>
1298         where
1299                 B::Target: BroadcasterInterface,
1300                 F::Target: FeeEstimator,
1301                 L::Target: Logger,
1302         {
1303                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1304                 self.inner.lock().unwrap().transactions_confirmed(
1305                         header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
1306         }
1307
1308         /// Processes a transaction that was reorganized out of the chain.
1309         ///
1310         /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1311         /// than blocks. See [`chain::Confirm`] for calling expectations.
1312         ///
1313         /// [`block_disconnected`]: Self::block_disconnected
1314         pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1315                 &self,
1316                 txid: &Txid,
1317                 broadcaster: B,
1318                 fee_estimator: F,
1319                 logger: L,
1320         ) where
1321                 B::Target: BroadcasterInterface,
1322                 F::Target: FeeEstimator,
1323                 L::Target: Logger,
1324         {
1325                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1326                 self.inner.lock().unwrap().transaction_unconfirmed(
1327                         txid, broadcaster, &bounded_fee_estimator, logger);
1328         }
1329
1330         /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1331         /// [`block_connected`] for details.
1332         ///
1333         /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1334         /// blocks. See [`chain::Confirm`] for calling expectations.
1335         ///
1336         /// [`block_connected`]: Self::block_connected
1337         pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1338                 &self,
1339                 header: &BlockHeader,
1340                 height: u32,
1341                 broadcaster: B,
1342                 fee_estimator: F,
1343                 logger: L,
1344         ) -> Vec<TransactionOutputs>
1345         where
1346                 B::Target: BroadcasterInterface,
1347                 F::Target: FeeEstimator,
1348                 L::Target: Logger,
1349         {
1350                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1351                 self.inner.lock().unwrap().best_block_updated(
1352                         header, height, broadcaster, &bounded_fee_estimator, logger)
1353         }
1354
1355         /// Returns the set of txids that should be monitored for re-organization out of the chain.
1356         pub fn get_relevant_txids(&self) -> Vec<Txid> {
1357                 let inner = self.inner.lock().unwrap();
1358                 let mut txids: Vec<Txid> = inner.onchain_events_awaiting_threshold_conf
1359                         .iter()
1360                         .map(|entry| entry.txid)
1361                         .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1362                         .collect();
1363                 txids.sort_unstable();
1364                 txids.dedup();
1365                 txids
1366         }
1367
1368         /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1369         /// [`chain::Confirm`] interfaces.
1370         pub fn current_best_block(&self) -> BestBlock {
1371                 self.inner.lock().unwrap().best_block.clone()
1372         }
1373
1374         /// Gets the balances in this channel which are either claimable by us if we were to
1375         /// force-close the channel now or which are claimable on-chain (possibly awaiting
1376         /// confirmation).
1377         ///
1378         /// Any balances in the channel which are available on-chain (excluding on-chain fees) are
1379         /// included here until an [`Event::SpendableOutputs`] event has been generated for the
1380         /// balance, or until our counterparty has claimed the balance and accrued several
1381         /// confirmations on the claim transaction.
1382         ///
1383         /// Note that the balances available when you or your counterparty have broadcasted revoked
1384         /// state(s) may not be fully captured here.
1385         // TODO, fix that ^
1386         ///
1387         /// See [`Balance`] for additional details on the types of claimable balances which
1388         /// may be returned here and their meanings.
1389         pub fn get_claimable_balances(&self) -> Vec<Balance> {
1390                 let mut res = Vec::new();
1391                 let us = self.inner.lock().unwrap();
1392
1393                 let mut confirmed_txid = us.funding_spend_confirmed;
1394                 let mut pending_commitment_tx_conf_thresh = None;
1395                 let funding_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1396                         if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1397                                 Some((event.txid, event.confirmation_threshold()))
1398                         } else { None }
1399                 });
1400                 if let Some((txid, conf_thresh)) = funding_spend_pending {
1401                         debug_assert!(us.funding_spend_confirmed.is_none(),
1402                                 "We have a pending funding spend awaiting anti-reorg confirmation, we can't have confirmed it already!");
1403                         confirmed_txid = Some(txid);
1404                         pending_commitment_tx_conf_thresh = Some(conf_thresh);
1405                 }
1406
1407                 macro_rules! walk_htlcs {
1408                         ($holder_commitment: expr, $htlc_iter: expr) => {
1409                                 for htlc in $htlc_iter {
1410                                         if let Some(htlc_commitment_tx_output_idx) = htlc.transaction_output_index {
1411                                                 if let Some(conf_thresh) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1412                                                         if let OnchainEvent::MaturingOutput { descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) } = &event.event {
1413                                                                 if descriptor.outpoint.index as u32 == htlc_commitment_tx_output_idx { Some(event.confirmation_threshold()) } else { None }
1414                                                         } else { None }
1415                                                 }) {
1416                                                         debug_assert!($holder_commitment);
1417                                                         res.push(Balance::ClaimableAwaitingConfirmations {
1418                                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1419                                                                 confirmation_height: conf_thresh,
1420                                                         });
1421                                                 } else if us.htlcs_resolved_on_chain.iter().any(|v| v.commitment_tx_output_idx == htlc_commitment_tx_output_idx) {
1422                                                         // Funding transaction spends should be fully confirmed by the time any
1423                                                         // HTLC transactions are resolved, unless we're talking about a holder
1424                                                         // commitment tx, whose resolution is delayed until the CSV timeout is
1425                                                         // reached, even though HTLCs may be resolved after only
1426                                                         // ANTI_REORG_DELAY confirmations.
1427                                                         debug_assert!($holder_commitment || us.funding_spend_confirmed.is_some());
1428                                                 } else if htlc.offered == $holder_commitment {
1429                                                         // If the payment was outbound, check if there's an HTLCUpdate
1430                                                         // indicating we have spent this HTLC with a timeout, claiming it back
1431                                                         // and awaiting confirmations on it.
1432                                                         let htlc_update_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1433                                                                 if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1434                                                                         if commitment_tx_output_idx == htlc_commitment_tx_output_idx {
1435                                                                                 Some(event.confirmation_threshold()) } else { None }
1436                                                                 } else { None }
1437                                                         });
1438                                                         if let Some(conf_thresh) = htlc_update_pending {
1439                                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1440                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1441                                                                         confirmation_height: conf_thresh,
1442                                                                 });
1443                                                         } else {
1444                                                                 res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1445                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1446                                                                         claimable_height: htlc.cltv_expiry,
1447                                                                 });
1448                                                         }
1449                                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1450                                                         // Otherwise (the payment was inbound), only expose it as claimable if
1451                                                         // we know the preimage.
1452                                                         // Note that if there is a pending claim, but it did not use the
1453                                                         // preimage, we lost funds to our counterparty! We will then continue
1454                                                         // to show it as ContentiousClaimable until ANTI_REORG_DELAY.
1455                                                         let htlc_spend_pending = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1456                                                                 if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } = event.event {
1457                                                                         if commitment_tx_output_idx == htlc_commitment_tx_output_idx {
1458                                                                                 Some((event.confirmation_threshold(), preimage.is_some()))
1459                                                                         } else { None }
1460                                                                 } else { None }
1461                                                         });
1462                                                         if let Some((conf_thresh, true)) = htlc_spend_pending {
1463                                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1464                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1465                                                                         confirmation_height: conf_thresh,
1466                                                                 });
1467                                                         } else {
1468                                                                 res.push(Balance::ContentiousClaimable {
1469                                                                         claimable_amount_satoshis: htlc.amount_msat / 1000,
1470                                                                         timeout_height: htlc.cltv_expiry,
1471                                                                 });
1472                                                         }
1473                                                 }
1474                                         }
1475                                 }
1476                         }
1477                 }
1478
1479                 if let Some(txid) = confirmed_txid {
1480                         let mut found_commitment_tx = false;
1481                         if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1482                                 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().map(|(a, _)| a));
1483                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1484                                         if let Some(value) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1485                                                 if let OnchainEvent::MaturingOutput {
1486                                                         descriptor: SpendableOutputDescriptor::StaticPaymentOutput(descriptor)
1487                                                 } = &event.event {
1488                                                         Some(descriptor.output.value)
1489                                                 } else { None }
1490                                         }) {
1491                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1492                                                         claimable_amount_satoshis: value,
1493                                                         confirmation_height: conf_thresh,
1494                                                 });
1495                                         } else {
1496                                                 // If a counterparty commitment transaction is awaiting confirmation, we
1497                                                 // should either have a StaticPaymentOutput MaturingOutput event awaiting
1498                                                 // confirmation with the same height or have never met our dust amount.
1499                                         }
1500                                 }
1501                                 found_commitment_tx = true;
1502                         } else if txid == us.current_holder_commitment_tx.txid {
1503                                 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
1504                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1505                                         res.push(Balance::ClaimableAwaitingConfirmations {
1506                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1507                                                 confirmation_height: conf_thresh,
1508                                         });
1509                                 }
1510                                 found_commitment_tx = true;
1511                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1512                                 if txid == prev_commitment.txid {
1513                                         walk_htlcs!(true, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
1514                                         if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1515                                                 res.push(Balance::ClaimableAwaitingConfirmations {
1516                                                         claimable_amount_satoshis: prev_commitment.to_self_value_sat,
1517                                                         confirmation_height: conf_thresh,
1518                                                 });
1519                                         }
1520                                         found_commitment_tx = true;
1521                                 }
1522                         }
1523                         if !found_commitment_tx {
1524                                 if let Some(conf_thresh) = pending_commitment_tx_conf_thresh {
1525                                         // We blindly assume this is a cooperative close transaction here, and that
1526                                         // neither us nor our counterparty misbehaved. At worst we've under-estimated
1527                                         // the amount we can claim as we'll punish a misbehaving counterparty.
1528                                         res.push(Balance::ClaimableAwaitingConfirmations {
1529                                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
1530                                                 confirmation_height: conf_thresh,
1531                                         });
1532                                 }
1533                         }
1534                         // TODO: Add logic to provide claimable balances for counterparty broadcasting revoked
1535                         // outputs.
1536                 } else {
1537                         let mut claimable_inbound_htlc_value_sat = 0;
1538                         for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
1539                                 if htlc.transaction_output_index.is_none() { continue; }
1540                                 if htlc.offered {
1541                                         res.push(Balance::MaybeClaimableHTLCAwaitingTimeout {
1542                                                 claimable_amount_satoshis: htlc.amount_msat / 1000,
1543                                                 claimable_height: htlc.cltv_expiry,
1544                                         });
1545                                 } else if us.payment_preimages.get(&htlc.payment_hash).is_some() {
1546                                         claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
1547                                 }
1548                         }
1549                         res.push(Balance::ClaimableOnChannelClose {
1550                                 claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
1551                         });
1552                 }
1553
1554                 res
1555         }
1556
1557         /// Gets the set of outbound HTLCs which are pending resolution in this channel.
1558         /// This is used to reconstruct pending outbound payments on restart in the ChannelManager.
1559         pub(crate) fn get_pending_outbound_htlcs(&self) -> HashMap<HTLCSource, HTLCOutputInCommitment> {
1560                 let mut res = HashMap::new();
1561                 let us = self.inner.lock().unwrap();
1562
1563                 macro_rules! walk_htlcs {
1564                         ($holder_commitment: expr, $htlc_iter: expr) => {
1565                                 for (htlc, source) in $htlc_iter {
1566                                         if us.htlcs_resolved_on_chain.iter().any(|v| Some(v.commitment_tx_output_idx) == htlc.transaction_output_index) {
1567                                                 // We should assert that funding_spend_confirmed is_some() here, but we
1568                                                 // have some unit tests which violate HTLC transaction CSVs entirely and
1569                                                 // would fail.
1570                                                 // TODO: Once tests all connect transactions at consensus-valid times, we
1571                                                 // should assert here like we do in `get_claimable_balances`.
1572                                         } else if htlc.offered == $holder_commitment {
1573                                                 // If the payment was outbound, check if there's an HTLCUpdate
1574                                                 // indicating we have spent this HTLC with a timeout, claiming it back
1575                                                 // and awaiting confirmations on it.
1576                                                 let htlc_update_confd = us.onchain_events_awaiting_threshold_conf.iter().any(|event| {
1577                                                         if let OnchainEvent::HTLCUpdate { commitment_tx_output_idx: Some(commitment_tx_output_idx), .. } = event.event {
1578                                                                 // If the HTLC was timed out, we wait for ANTI_REORG_DELAY blocks
1579                                                                 // before considering it "no longer pending" - this matches when we
1580                                                                 // provide the ChannelManager an HTLC failure event.
1581                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index &&
1582                                                                         us.best_block.height() >= event.height + ANTI_REORG_DELAY - 1
1583                                                         } else if let OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, .. } = event.event {
1584                                                                 // If the HTLC was fulfilled with a preimage, we consider the HTLC
1585                                                                 // immediately non-pending, matching when we provide ChannelManager
1586                                                                 // the preimage.
1587                                                                 Some(commitment_tx_output_idx) == htlc.transaction_output_index
1588                                                         } else { false }
1589                                                 });
1590                                                 if !htlc_update_confd {
1591                                                         res.insert(source.clone(), htlc.clone());
1592                                                 }
1593                                         }
1594                                 }
1595                         }
1596                 }
1597
1598                 // We're only concerned with the confirmation count of HTLC transactions, and don't
1599                 // actually care how many confirmations a commitment transaction may or may not have. Thus,
1600                 // we look for either a FundingSpendConfirmation event or a funding_spend_confirmed.
1601                 let confirmed_txid = us.funding_spend_confirmed.or_else(|| {
1602                         us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
1603                                 if let OnchainEvent::FundingSpendConfirmation { .. } = event.event {
1604                                         Some(event.txid)
1605                                 } else { None }
1606                         })
1607                 });
1608                 if let Some(txid) = confirmed_txid {
1609                         if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
1610                                 walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().filter_map(|(a, b)| {
1611                                         if let &Some(ref source) = b {
1612                                                 Some((a, &**source))
1613                                         } else { None }
1614                                 }));
1615                         } else if txid == us.current_holder_commitment_tx.txid {
1616                                 walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().filter_map(|(a, _, c)| {
1617                                         if let Some(source) = c { Some((a, source)) } else { None }
1618                                 }));
1619                         } else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
1620                                 if txid == prev_commitment.txid {
1621                                         walk_htlcs!(true, prev_commitment.htlc_outputs.iter().filter_map(|(a, _, c)| {
1622                                                 if let Some(source) = c { Some((a, source)) } else { None }
1623                                         }));
1624                                 }
1625                         }
1626                 } else {
1627                         // If we have not seen a commitment transaction on-chain (ie the channel is not yet
1628                         // closed), just examine the available counterparty commitment transactions. See docs
1629                         // on `fail_unbroadcast_htlcs`, below, for justification.
1630                         macro_rules! walk_counterparty_commitment {
1631                                 ($txid: expr) => {
1632                                         if let Some(ref latest_outpoints) = us.counterparty_claimable_outpoints.get($txid) {
1633                                                 for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1634                                                         if let &Some(ref source) = source_option {
1635                                                                 res.insert((**source).clone(), htlc.clone());
1636                                                         }
1637                                                 }
1638                                         }
1639                                 }
1640                         }
1641                         if let Some(ref txid) = us.current_counterparty_commitment_txid {
1642                                 walk_counterparty_commitment!(txid);
1643                         }
1644                         if let Some(ref txid) = us.prev_counterparty_commitment_txid {
1645                                 walk_counterparty_commitment!(txid);
1646                         }
1647                 }
1648
1649                 res
1650         }
1651
1652         pub(crate) fn get_stored_preimages(&self) -> HashMap<PaymentHash, PaymentPreimage> {
1653                 self.inner.lock().unwrap().payment_preimages.clone()
1654         }
1655 }
1656
1657 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,
1658 /// failing any HTLCs which didn't make it into the broadcasted commitment transaction back
1659 /// after ANTI_REORG_DELAY blocks.
1660 ///
1661 /// We always compare against the set of HTLCs in counterparty commitment transactions, as those
1662 /// are the commitment transactions which are generated by us. The off-chain state machine in
1663 /// `Channel` will automatically resolve any HTLCs which were never included in a commitment
1664 /// transaction when it detects channel closure, but it is up to us to ensure any HTLCs which were
1665 /// included in a remote commitment transaction are failed back if they are not present in the
1666 /// broadcasted commitment transaction.
1667 ///
1668 /// Specifically, the removal process for HTLCs in `Channel` is always based on the counterparty
1669 /// sending a `revoke_and_ack`, which causes us to clear `prev_counterparty_commitment_txid`. Thus,
1670 /// as long as we examine both the current counterparty commitment transaction and, if it hasn't
1671 /// been revoked yet, the previous one, we we will never "forget" to resolve an HTLC.
1672 macro_rules! fail_unbroadcast_htlcs {
1673         ($self: expr, $commitment_tx_type: expr, $commitment_txid_confirmed: expr,
1674          $commitment_tx_conf_height: expr, $confirmed_htlcs_list: expr, $logger: expr) => { {
1675                 macro_rules! check_htlc_fails {
1676                         ($txid: expr, $commitment_tx: expr) => {
1677                                 if let Some(ref latest_outpoints) = $self.counterparty_claimable_outpoints.get($txid) {
1678                                         for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1679                                                 if let &Some(ref source) = source_option {
1680                                                         // Check if the HTLC is present in the commitment transaction that was
1681                                                         // broadcast, but not if it was below the dust limit, which we should
1682                                                         // fail backwards immediately as there is no way for us to learn the
1683                                                         // payment_preimage.
1684                                                         // Note that if the dust limit were allowed to change between
1685                                                         // commitment transactions we'd want to be check whether *any*
1686                                                         // broadcastable commitment transaction has the HTLC in it, but it
1687                                                         // cannot currently change after channel initialization, so we don't
1688                                                         // need to here.
1689                                                         let confirmed_htlcs_iter: &mut Iterator<Item = (&HTLCOutputInCommitment, Option<&HTLCSource>)> = &mut $confirmed_htlcs_list;
1690
1691                                                         let mut matched_htlc = false;
1692                                                         for (ref broadcast_htlc, ref broadcast_source) in confirmed_htlcs_iter {
1693                                                                 if broadcast_htlc.transaction_output_index.is_some() &&
1694                                                                         (Some(&**source) == *broadcast_source ||
1695                                                                          (broadcast_source.is_none() &&
1696                                                                           broadcast_htlc.payment_hash == htlc.payment_hash &&
1697                                                                           broadcast_htlc.amount_msat == htlc.amount_msat)) {
1698                                                                         matched_htlc = true;
1699                                                                         break;
1700                                                                 }
1701                                                         }
1702                                                         if matched_htlc { continue; }
1703                                                         $self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1704                                                                 if entry.height != $commitment_tx_conf_height { return true; }
1705                                                                 match entry.event {
1706                                                                         OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1707                                                                                 *update_source != **source
1708                                                                         },
1709                                                                         _ => true,
1710                                                                 }
1711                                                         });
1712                                                         let entry = OnchainEventEntry {
1713                                                                 txid: $commitment_txid_confirmed,
1714                                                                 height: $commitment_tx_conf_height,
1715                                                                 event: OnchainEvent::HTLCUpdate {
1716                                                                         source: (**source).clone(),
1717                                                                         payment_hash: htlc.payment_hash.clone(),
1718                                                                         htlc_value_satoshis: Some(htlc.amount_msat / 1000),
1719                                                                         commitment_tx_output_idx: None,
1720                                                                 },
1721                                                         };
1722                                                         log_trace!($logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of {} commitment transaction {}, waiting for confirmation (at height {})",
1723                                                                 log_bytes!(htlc.payment_hash.0), $commitment_tx, $commitment_tx_type,
1724                                                                 $commitment_txid_confirmed, entry.confirmation_threshold());
1725                                                         $self.onchain_events_awaiting_threshold_conf.push(entry);
1726                                                 }
1727                                         }
1728                                 }
1729                         }
1730                 }
1731                 if let Some(ref txid) = $self.current_counterparty_commitment_txid {
1732                         check_htlc_fails!(txid, "current");
1733                 }
1734                 if let Some(ref txid) = $self.prev_counterparty_commitment_txid {
1735                         check_htlc_fails!(txid, "previous");
1736                 }
1737         } }
1738 }
1739
1740 // In the `test_invalid_funding_tx` test, we need a bogus script which matches the HTLC-Accepted
1741 // witness length match (ie is 136 bytes long). We generate one here which we also use in some
1742 // in-line tests later.
1743
1744 #[cfg(test)]
1745 pub fn deliberately_bogus_accepted_htlc_witness_program() -> Vec<u8> {
1746         let mut ret = [opcodes::all::OP_NOP.into_u8(); 136];
1747         ret[131] = opcodes::all::OP_DROP.into_u8();
1748         ret[132] = opcodes::all::OP_DROP.into_u8();
1749         ret[133] = opcodes::all::OP_DROP.into_u8();
1750         ret[134] = opcodes::all::OP_DROP.into_u8();
1751         ret[135] = opcodes::OP_TRUE.into_u8();
1752         Vec::from(&ret[..])
1753 }
1754
1755 #[cfg(test)]
1756 pub fn deliberately_bogus_accepted_htlc_witness() -> Vec<Vec<u8>> {
1757         vec![Vec::new(), Vec::new(), Vec::new(), Vec::new(), deliberately_bogus_accepted_htlc_witness_program().into()].into()
1758 }
1759
1760 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1761         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1762         /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1763         /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1764         fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), &'static str> {
1765                 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1766                         return Err("Previous secret did not match new one");
1767                 }
1768
1769                 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1770                 // events for now-revoked/fulfilled HTLCs.
1771                 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1772                         for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1773                                 *source = None;
1774                         }
1775                 }
1776
1777                 if !self.payment_preimages.is_empty() {
1778                         let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1779                         let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1780                         let min_idx = self.get_min_seen_secret();
1781                         let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1782
1783                         self.payment_preimages.retain(|&k, _| {
1784                                 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1785                                         if k == htlc.payment_hash {
1786                                                 return true
1787                                         }
1788                                 }
1789                                 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1790                                         for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1791                                                 if k == htlc.payment_hash {
1792                                                         return true
1793                                                 }
1794                                         }
1795                                 }
1796                                 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1797                                         if *cn < min_idx {
1798                                                 return true
1799                                         }
1800                                         true
1801                                 } else { false };
1802                                 if contains {
1803                                         counterparty_hash_commitment_number.remove(&k);
1804                                 }
1805                                 false
1806                         });
1807                 }
1808
1809                 Ok(())
1810         }
1811
1812         pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_per_commitment_point: PublicKey, logger: &L) where L::Target: Logger {
1813                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1814                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1815                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1816                 // timeouts)
1817                 for &(ref htlc, _) in &htlc_outputs {
1818                         self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1819                 }
1820
1821                 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1822                 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1823                 self.current_counterparty_commitment_txid = Some(txid);
1824                 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1825                 self.current_counterparty_commitment_number = commitment_number;
1826                 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1827                 match self.their_cur_per_commitment_points {
1828                         Some(old_points) => {
1829                                 if old_points.0 == commitment_number + 1 {
1830                                         self.their_cur_per_commitment_points = Some((old_points.0, old_points.1, Some(their_per_commitment_point)));
1831                                 } else if old_points.0 == commitment_number + 2 {
1832                                         if let Some(old_second_point) = old_points.2 {
1833                                                 self.their_cur_per_commitment_points = Some((old_points.0 - 1, old_second_point, Some(their_per_commitment_point)));
1834                                         } else {
1835                                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
1836                                         }
1837                                 } else {
1838                                         self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
1839                                 }
1840                         },
1841                         None => {
1842                                 self.their_cur_per_commitment_points = Some((commitment_number, their_per_commitment_point, None));
1843                         }
1844                 }
1845                 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1846                 for htlc in htlc_outputs {
1847                         if htlc.0.transaction_output_index.is_some() {
1848                                 htlcs.push(htlc.0);
1849                         }
1850                 }
1851         }
1852
1853         /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1854         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1855         /// is important that any clones of this channel monitor (including remote clones) by kept
1856         /// up-to-date as our holder commitment transaction is updated.
1857         /// Panics if set_on_holder_tx_csv has never been called.
1858         fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), &'static str> {
1859                 // block for Rust 1.34 compat
1860                 let mut new_holder_commitment_tx = {
1861                         let trusted_tx = holder_commitment_tx.trust();
1862                         let txid = trusted_tx.txid();
1863                         let tx_keys = trusted_tx.keys();
1864                         self.current_holder_commitment_number = trusted_tx.commitment_number();
1865                         HolderSignedTx {
1866                                 txid,
1867                                 revocation_key: tx_keys.revocation_key,
1868                                 a_htlc_key: tx_keys.broadcaster_htlc_key,
1869                                 b_htlc_key: tx_keys.countersignatory_htlc_key,
1870                                 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1871                                 per_commitment_point: tx_keys.per_commitment_point,
1872                                 htlc_outputs,
1873                                 to_self_value_sat: holder_commitment_tx.to_broadcaster_value_sat(),
1874                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1875                         }
1876                 };
1877                 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1878                 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1879                 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1880                 if self.holder_tx_signed {
1881                         return Err("Latest holder commitment signed has already been signed, update is rejected");
1882                 }
1883                 Ok(())
1884         }
1885
1886         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1887         /// commitment_tx_infos which contain the payment hash have been revoked.
1888         fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
1889                 &mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B,
1890                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
1891         where B::Target: BroadcasterInterface,
1892                     F::Target: FeeEstimator,
1893                     L::Target: Logger,
1894         {
1895                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1896
1897                 // If the channel is force closed, try to claim the output from this preimage.
1898                 // First check if a counterparty commitment transaction has been broadcasted:
1899                 macro_rules! claim_htlcs {
1900                         ($commitment_number: expr, $txid: expr) => {
1901                                 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1902                                 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1903                         }
1904                 }
1905                 if let Some(txid) = self.current_counterparty_commitment_txid {
1906                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1907                                 claim_htlcs!(*commitment_number, txid);
1908                                 return;
1909                         }
1910                 }
1911                 if let Some(txid) = self.prev_counterparty_commitment_txid {
1912                         if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1913                                 claim_htlcs!(*commitment_number, txid);
1914                                 return;
1915                         }
1916                 }
1917
1918                 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1919                 // claiming the HTLC output from each of the holder commitment transactions.
1920                 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1921                 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1922                 // holder commitment transactions.
1923                 if self.broadcasted_holder_revokable_script.is_some() {
1924                         // Assume that the broadcasted commitment transaction confirmed in the current best
1925                         // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
1926                         // transactions.
1927                         let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
1928                         self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1929                         if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1930                                 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
1931                                 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1932                         }
1933                 }
1934         }
1935
1936         pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1937                 where B::Target: BroadcasterInterface,
1938                                         L::Target: Logger,
1939         {
1940                 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1941                         log_info!(logger, "Broadcasting local {}", log_tx!(tx));
1942                         broadcaster.broadcast_transaction(tx);
1943                 }
1944                 self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
1945         }
1946
1947         pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), ()>
1948         where B::Target: BroadcasterInterface,
1949                     F::Target: FeeEstimator,
1950                     L::Target: Logger,
1951         {
1952                 log_info!(logger, "Applying update to monitor {}, bringing update_id from {} to {} with {} changes.",
1953                         log_funding_info!(self), self.latest_update_id, updates.update_id, updates.updates.len());
1954                 // ChannelMonitor updates may be applied after force close if we receive a
1955                 // preimage for a broadcasted commitment transaction HTLC output that we'd
1956                 // like to claim on-chain. If this is the case, we no longer have guaranteed
1957                 // access to the monitor's update ID, so we use a sentinel value instead.
1958                 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1959                         assert_eq!(updates.updates.len(), 1);
1960                         match updates.updates[0] {
1961                                 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1962                                 _ => {
1963                                         log_error!(logger, "Attempted to apply post-force-close ChannelMonitorUpdate of type {}", updates.updates[0].variant_name());
1964                                         panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage");
1965                                 },
1966                         }
1967                 } else if self.latest_update_id + 1 != updates.update_id {
1968                         panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1969                 }
1970                 let mut ret = Ok(());
1971                 for update in updates.updates.iter() {
1972                         match update {
1973                                 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1974                                         log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1975                                         if self.lockdown_from_offchain { panic!(); }
1976                                         if let Err(e) = self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone()) {
1977                                                 log_error!(logger, "Providing latest holder commitment transaction failed/was refused:");
1978                                                 log_error!(logger, "    {}", e);
1979                                                 ret = Err(());
1980                                         }
1981                                 }
1982                                 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_per_commitment_point } => {
1983                                         log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1984                                         self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_per_commitment_point, logger)
1985                                 },
1986                                 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1987                                         log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1988                                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
1989                                         self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, &bounded_fee_estimator, logger)
1990                                 },
1991                                 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1992                                         log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1993                                         if let Err(e) = self.provide_secret(*idx, *secret) {
1994                                                 log_error!(logger, "Providing latest counterparty commitment secret failed/was refused:");
1995                                                 log_error!(logger, "    {}", e);
1996                                                 ret = Err(());
1997                                         }
1998                                 },
1999                                 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
2000                                         log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
2001                                         self.lockdown_from_offchain = true;
2002                                         if *should_broadcast {
2003                                                 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
2004                                         } else if !self.holder_tx_signed {
2005                                                 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");
2006                                         } else {
2007                                                 // If we generated a MonitorEvent::CommitmentTxConfirmed, the ChannelManager
2008                                                 // will still give us a ChannelForceClosed event with !should_broadcast, but we
2009                                                 // shouldn't print the scary warning above.
2010                                                 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
2011                                         }
2012                                 },
2013                                 ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
2014                                         log_trace!(logger, "Updating ChannelMonitor with shutdown script");
2015                                         if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
2016                                                 panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
2017                                         }
2018                                 },
2019                         }
2020                 }
2021                 self.latest_update_id = updates.update_id;
2022
2023                 if ret.is_ok() && self.funding_spend_seen {
2024                         log_error!(logger, "Refusing Channel Monitor Update as counterparty attempted to update commitment after funding was spent");
2025                         Err(())
2026                 } else { ret }
2027         }
2028
2029         pub fn get_latest_update_id(&self) -> u64 {
2030                 self.latest_update_id
2031         }
2032
2033         pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
2034                 &self.funding_info
2035         }
2036
2037         pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
2038                 // If we've detected a counterparty commitment tx on chain, we must include it in the set
2039                 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
2040                 // its trivial to do, double-check that here.
2041                 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
2042                         self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
2043                 }
2044                 &self.outputs_to_watch
2045         }
2046
2047         pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
2048                 let mut ret = Vec::new();
2049                 mem::swap(&mut ret, &mut self.pending_monitor_events);
2050                 ret
2051         }
2052
2053         pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
2054                 let mut ret = Vec::new();
2055                 mem::swap(&mut ret, &mut self.pending_events);
2056                 ret
2057         }
2058
2059         /// Can only fail if idx is < get_min_seen_secret
2060         fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
2061                 self.commitment_secrets.get_secret(idx)
2062         }
2063
2064         pub(crate) fn get_min_seen_secret(&self) -> u64 {
2065                 self.commitment_secrets.get_min_seen_secret()
2066         }
2067
2068         pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
2069                 self.current_counterparty_commitment_number
2070         }
2071
2072         pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
2073                 self.current_holder_commitment_number
2074         }
2075
2076         /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
2077         /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
2078         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
2079         /// HTLC-Success/HTLC-Timeout transactions.
2080         /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
2081         /// revoked counterparty commitment tx
2082         fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<PackageTemplate>, TransactionOutputs) where L::Target: Logger {
2083                 // Most secp and related errors trying to create keys means we have no hope of constructing
2084                 // a spend transaction...so we return no transactions to broadcast
2085                 let mut claimable_outpoints = Vec::new();
2086                 let mut watch_outputs = Vec::new();
2087
2088                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
2089                 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
2090
2091                 macro_rules! ignore_error {
2092                         ( $thing : expr ) => {
2093                                 match $thing {
2094                                         Ok(a) => a,
2095                                         Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
2096                                 }
2097                         };
2098                 }
2099
2100                 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);
2101                 if commitment_number >= self.get_min_seen_secret() {
2102                         let secret = self.get_secret(commitment_number).unwrap();
2103                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2104                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2105                         let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
2106                         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));
2107
2108                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_commitment_params.on_counterparty_tx_csv, &delayed_key);
2109                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
2110
2111                         // First, process non-htlc outputs (to_holder & to_counterparty)
2112                         for (idx, outp) in tx.output.iter().enumerate() {
2113                                 if outp.script_pubkey == revokeable_p2wsh {
2114                                         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);
2115                                         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);
2116                                         claimable_outpoints.push(justice_package);
2117                                 }
2118                         }
2119
2120                         // Then, try to find revoked htlc outputs
2121                         if let Some(ref per_commitment_data) = per_commitment_option {
2122                                 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
2123                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2124                                                 if transaction_output_index as usize >= tx.output.len() ||
2125                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2126                                                         return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
2127                                                 }
2128                                                 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());
2129                                                 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
2130                                                 claimable_outpoints.push(justice_package);
2131                                         }
2132                                 }
2133                         }
2134
2135                         // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
2136                         if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
2137                                 // We're definitely a counterparty commitment transaction!
2138                                 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
2139                                 for (idx, outp) in tx.output.iter().enumerate() {
2140                                         watch_outputs.push((idx as u32, outp.clone()));
2141                                 }
2142                                 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2143
2144                                 if let Some(per_commitment_data) = per_commitment_option {
2145                                         fail_unbroadcast_htlcs!(self, "revoked_counterparty", commitment_txid, height,
2146                                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2147                                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2148                                                 ), logger);
2149                                 } else {
2150                                         debug_assert!(false, "We should have per-commitment option for any recognized old commitment txn");
2151                                         fail_unbroadcast_htlcs!(self, "revoked counterparty", commitment_txid, height,
2152                                                 [].iter().map(|reference| *reference), logger);
2153                                 }
2154                         }
2155                 } else if let Some(per_commitment_data) = per_commitment_option {
2156                         // While this isn't useful yet, there is a potential race where if a counterparty
2157                         // revokes a state at the same time as the commitment transaction for that state is
2158                         // confirmed, and the watchtower receives the block before the user, the user could
2159                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
2160                         // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
2161                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
2162                         // insert it here.
2163                         for (idx, outp) in tx.output.iter().enumerate() {
2164                                 watch_outputs.push((idx as u32, outp.clone()));
2165                         }
2166                         self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
2167
2168                         log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
2169                         fail_unbroadcast_htlcs!(self, "counterparty", commitment_txid, height,
2170                                 per_commitment_data.iter().map(|(htlc, htlc_source)|
2171                                         (htlc, htlc_source.as_ref().map(|htlc_source| htlc_source.as_ref()))
2172                                 ), logger);
2173
2174                         let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
2175                         for req in htlc_claim_reqs {
2176                                 claimable_outpoints.push(req);
2177                         }
2178
2179                 }
2180                 (claimable_outpoints, (commitment_txid, watch_outputs))
2181         }
2182
2183         fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<PackageTemplate> {
2184                 let mut claimable_outpoints = Vec::new();
2185                 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
2186                         if let Some(per_commitment_points) = self.their_cur_per_commitment_points {
2187                                 let per_commitment_point_option =
2188                                         // If the counterparty commitment tx is the latest valid state, use their latest
2189                                         // per-commitment point
2190                                         if per_commitment_points.0 == commitment_number { Some(&per_commitment_points.1) }
2191                                         else if let Some(point) = per_commitment_points.2.as_ref() {
2192                                                 // If counterparty commitment tx is the state previous to the latest valid state, use
2193                                                 // their previous per-commitment point (non-atomicity of revocation means it's valid for
2194                                                 // them to temporarily have two valid commitment txns from our viewpoint)
2195                                                 if per_commitment_points.0 == commitment_number + 1 { Some(point) } else { None }
2196                                         } else { None };
2197                                 if let Some(per_commitment_point) = per_commitment_point_option {
2198                                         for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
2199                                                 if let Some(transaction_output_index) = htlc.transaction_output_index {
2200                                                         if let Some(transaction) = tx {
2201                                                                 if transaction_output_index as usize >= transaction.output.len() ||
2202                                                                         transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
2203                                                                                 return claimable_outpoints; // Corrupted per_commitment_data, fuck this user
2204                                                                         }
2205                                                         }
2206                                                         let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
2207                                                         if preimage.is_some() || !htlc.offered {
2208                                                                 let counterparty_htlc_outp = if htlc.offered {
2209                                                                         PackageSolvingData::CounterpartyOfferedHTLCOutput(
2210                                                                                 CounterpartyOfferedHTLCOutput::build(*per_commitment_point,
2211                                                                                         self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2212                                                                                         self.counterparty_commitment_params.counterparty_htlc_base_key,
2213                                                                                         preimage.unwrap(), htlc.clone()))
2214                                                                 } else {
2215                                                                         PackageSolvingData::CounterpartyReceivedHTLCOutput(
2216                                                                                 CounterpartyReceivedHTLCOutput::build(*per_commitment_point,
2217                                                                                         self.counterparty_commitment_params.counterparty_delayed_payment_base_key,
2218                                                                                         self.counterparty_commitment_params.counterparty_htlc_base_key,
2219                                                                                         htlc.clone()))
2220                                                                 };
2221                                                                 let aggregation = if !htlc.offered { false } else { true };
2222                                                                 let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
2223                                                                 claimable_outpoints.push(counterparty_package);
2224                                                         }
2225                                                 }
2226                                         }
2227                                 }
2228                         }
2229                 }
2230                 claimable_outpoints
2231         }
2232
2233         /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
2234         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 {
2235                 let htlc_txid = tx.txid();
2236                 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
2237                         return (Vec::new(), None)
2238                 }
2239
2240                 macro_rules! ignore_error {
2241                         ( $thing : expr ) => {
2242                                 match $thing {
2243                                         Ok(a) => a,
2244                                         Err(_) => return (Vec::new(), None)
2245                                 }
2246                         };
2247                 }
2248
2249                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
2250                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
2251                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
2252
2253                 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, 0);
2254                 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);
2255                 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);
2256                 let claimable_outpoints = vec!(justice_package);
2257                 let outputs = vec![(0, tx.output[0].clone())];
2258                 (claimable_outpoints, Some((htlc_txid, outputs)))
2259         }
2260
2261         // Returns (1) `PackageTemplate`s that can be given to the OnChainTxHandler, so that the handler can
2262         // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
2263         // script so we can detect whether a holder transaction has been seen on-chain.
2264         fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
2265                 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
2266
2267                 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
2268                 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
2269
2270                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2271                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2272                                 let htlc_output = if htlc.offered {
2273                                                 HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
2274                                         } else {
2275                                                 let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
2276                                                         preimage.clone()
2277                                                 } else {
2278                                                         // We can't build an HTLC-Success transaction without the preimage
2279                                                         continue;
2280                                                 };
2281                                                 HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
2282                                         };
2283                                 let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
2284                                 claim_requests.push(htlc_package);
2285                         }
2286                 }
2287
2288                 (claim_requests, broadcasted_holder_revokable_script)
2289         }
2290
2291         // Returns holder HTLC outputs to watch and react to in case of spending.
2292         fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
2293                 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
2294                 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
2295                         if let Some(transaction_output_index) = htlc.transaction_output_index {
2296                                 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
2297                         }
2298                 }
2299                 watch_outputs
2300         }
2301
2302         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
2303         /// revoked using data in holder_claimable_outpoints.
2304         /// Should not be used if check_spend_revoked_transaction succeeds.
2305         /// Returns None unless the transaction is definitely one of our commitment transactions.
2306         fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> Option<(Vec<PackageTemplate>, TransactionOutputs)> where L::Target: Logger {
2307                 let commitment_txid = tx.txid();
2308                 let mut claim_requests = Vec::new();
2309                 let mut watch_outputs = Vec::new();
2310
2311                 macro_rules! append_onchain_update {
2312                         ($updates: expr, $to_watch: expr) => {
2313                                 claim_requests = $updates.0;
2314                                 self.broadcasted_holder_revokable_script = $updates.1;
2315                                 watch_outputs.append(&mut $to_watch);
2316                         }
2317                 }
2318
2319                 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
2320                 let mut is_holder_tx = false;
2321
2322                 if self.current_holder_commitment_tx.txid == commitment_txid {
2323                         is_holder_tx = true;
2324                         log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2325                         let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
2326                         let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
2327                         append_onchain_update!(res, to_watch);
2328                         fail_unbroadcast_htlcs!(self, "latest holder", commitment_txid, height,
2329                                 self.current_holder_commitment_tx.htlc_outputs.iter()
2330                                 .map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())), logger);
2331                 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
2332                         if holder_tx.txid == commitment_txid {
2333                                 is_holder_tx = true;
2334                                 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
2335                                 let res = self.get_broadcasted_holder_claims(holder_tx, height);
2336                                 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
2337                                 append_onchain_update!(res, to_watch);
2338                                 fail_unbroadcast_htlcs!(self, "previous holder", commitment_txid, height,
2339                                         holder_tx.htlc_outputs.iter().map(|(htlc, _, htlc_source)| (htlc, htlc_source.as_ref())),
2340                                         logger);
2341                         }
2342                 }
2343
2344                 if is_holder_tx {
2345                         Some((claim_requests, (commitment_txid, watch_outputs)))
2346                 } else {
2347                         None
2348                 }
2349         }
2350
2351         pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2352                 log_debug!(logger, "Getting signed latest holder commitment transaction!");
2353                 self.holder_tx_signed = true;
2354                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2355                 let txid = commitment_tx.txid();
2356                 let mut holder_transactions = vec![commitment_tx];
2357                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2358                         if let Some(vout) = htlc.0.transaction_output_index {
2359                                 let preimage = if !htlc.0.offered {
2360                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2361                                                 // We can't build an HTLC-Success transaction without the preimage
2362                                                 continue;
2363                                         }
2364                                 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
2365                                         // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
2366                                         // current locktime requirements on-chain. We will broadcast them in
2367                                         // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
2368                                         // Note that we add + 1 as transactions are broadcastable when they can be
2369                                         // confirmed in the next block.
2370                                         continue;
2371                                 } else { None };
2372                                 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
2373                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2374                                         holder_transactions.push(htlc_tx);
2375                                 }
2376                         }
2377                 }
2378                 // 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.
2379                 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
2380                 holder_transactions
2381         }
2382
2383         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
2384         /// Note that this includes possibly-locktimed-in-the-future transactions!
2385         fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
2386                 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
2387                 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
2388                 let txid = commitment_tx.txid();
2389                 let mut holder_transactions = vec![commitment_tx];
2390                 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
2391                         if let Some(vout) = htlc.0.transaction_output_index {
2392                                 let preimage = if !htlc.0.offered {
2393                                         if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
2394                                                 // We can't build an HTLC-Success transaction without the preimage
2395                                                 continue;
2396                                         }
2397                                 } else { None };
2398                                 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
2399                                         &::bitcoin::OutPoint { txid, vout }, &preimage) {
2400                                         holder_transactions.push(htlc_tx);
2401                                 }
2402                         }
2403                 }
2404                 holder_transactions
2405         }
2406
2407         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>
2408                 where B::Target: BroadcasterInterface,
2409                       F::Target: FeeEstimator,
2410                                         L::Target: Logger,
2411         {
2412                 let block_hash = header.block_hash();
2413                 self.best_block = BestBlock::new(block_hash, height);
2414
2415                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2416                 self.transactions_confirmed(header, txdata, height, broadcaster, &bounded_fee_estimator, logger)
2417         }
2418
2419         fn best_block_updated<B: Deref, F: Deref, L: Deref>(
2420                 &mut self,
2421                 header: &BlockHeader,
2422                 height: u32,
2423                 broadcaster: B,
2424                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2425                 logger: L,
2426         ) -> Vec<TransactionOutputs>
2427         where
2428                 B::Target: BroadcasterInterface,
2429                 F::Target: FeeEstimator,
2430                 L::Target: Logger,
2431         {
2432                 let block_hash = header.block_hash();
2433
2434                 if height > self.best_block.height() {
2435                         self.best_block = BestBlock::new(block_hash, height);
2436                         self.block_confirmed(height, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
2437                 } else if block_hash != self.best_block.block_hash() {
2438                         self.best_block = BestBlock::new(block_hash, height);
2439                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
2440                         self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
2441                         Vec::new()
2442                 } else { Vec::new() }
2443         }
2444
2445         fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
2446                 &mut self,
2447                 header: &BlockHeader,
2448                 txdata: &TransactionData,
2449                 height: u32,
2450                 broadcaster: B,
2451                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2452                 logger: L,
2453         ) -> Vec<TransactionOutputs>
2454         where
2455                 B::Target: BroadcasterInterface,
2456                 F::Target: FeeEstimator,
2457                 L::Target: Logger,
2458         {
2459                 let txn_matched = self.filter_block(txdata);
2460                 for tx in &txn_matched {
2461                         let mut output_val = 0;
2462                         for out in tx.output.iter() {
2463                                 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2464                                 output_val += out.value;
2465                                 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
2466                         }
2467                 }
2468
2469                 let block_hash = header.block_hash();
2470
2471                 let mut watch_outputs = Vec::new();
2472                 let mut claimable_outpoints = Vec::new();
2473                 for tx in &txn_matched {
2474                         if tx.input.len() == 1 {
2475                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
2476                                 // commitment transactions and HTLC transactions will all only ever have one input,
2477                                 // which is an easy way to filter out any potential non-matching txn for lazy
2478                                 // filters.
2479                                 let prevout = &tx.input[0].previous_output;
2480                                 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
2481                                         let mut balance_spendable_csv = None;
2482                                         log_info!(logger, "Channel {} closed by funding output spend in txid {}.",
2483                                                 log_bytes!(self.funding_info.0.to_channel_id()), tx.txid());
2484                                         self.funding_spend_seen = true;
2485                                         if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
2486                                                 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
2487                                                 if !new_outputs.1.is_empty() {
2488                                                         watch_outputs.push(new_outputs);
2489                                                 }
2490                                                 claimable_outpoints.append(&mut new_outpoints);
2491                                                 if new_outpoints.is_empty() {
2492                                                         if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &logger) {
2493                                                                 if !new_outputs.1.is_empty() {
2494                                                                         watch_outputs.push(new_outputs);
2495                                                                 }
2496                                                                 claimable_outpoints.append(&mut new_outpoints);
2497                                                                 balance_spendable_csv = Some(self.on_holder_tx_csv);
2498                                                         }
2499                                                 }
2500                                         }
2501                                         let txid = tx.txid();
2502                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2503                                                 txid,
2504                                                 height: height,
2505                                                 event: OnchainEvent::FundingSpendConfirmation {
2506                                                         on_local_output_csv: balance_spendable_csv,
2507                                                 },
2508                                         });
2509                                 } else {
2510                                         if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2511                                                 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2512                                                 claimable_outpoints.append(&mut new_outpoints);
2513                                                 if let Some(new_outputs) = new_outputs_option {
2514                                                         watch_outputs.push(new_outputs);
2515                                                 }
2516                                         }
2517                                 }
2518                         }
2519                         // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2520                         // can also be resolved in a few other ways which can have more than one output. Thus,
2521                         // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2522                         self.is_resolving_htlc_output(&tx, height, &logger);
2523
2524                         self.is_paying_spendable_output(&tx, height, &logger);
2525                 }
2526
2527                 if height > self.best_block.height() {
2528                         self.best_block = BestBlock::new(block_hash, height);
2529                 }
2530
2531                 self.block_confirmed(height, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
2532         }
2533
2534         /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
2535         /// `self.best_block` before calling if a new best blockchain tip is available. More
2536         /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
2537         /// complexity especially in `OnchainTx::update_claims_view`.
2538         ///
2539         /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
2540         /// confirmed at, even if it is not the current best height.
2541         fn block_confirmed<B: Deref, F: Deref, L: Deref>(
2542                 &mut self,
2543                 conf_height: u32,
2544                 txn_matched: Vec<&Transaction>,
2545                 mut watch_outputs: Vec<TransactionOutputs>,
2546                 mut claimable_outpoints: Vec<PackageTemplate>,
2547                 broadcaster: &B,
2548                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2549                 logger: &L,
2550         ) -> Vec<TransactionOutputs>
2551         where
2552                 B::Target: BroadcasterInterface,
2553                 F::Target: FeeEstimator,
2554                 L::Target: Logger,
2555         {
2556                 log_trace!(logger, "Processing {} matched transactions for block at height {}.", txn_matched.len(), conf_height);
2557                 debug_assert!(self.best_block.height() >= conf_height);
2558
2559                 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
2560                 if should_broadcast {
2561                         let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
2562                         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());
2563                         claimable_outpoints.push(commitment_package);
2564                         self.pending_monitor_events.push(MonitorEvent::CommitmentTxConfirmed(self.funding_info.0));
2565                         let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2566                         self.holder_tx_signed = true;
2567                         // Because we're broadcasting a commitment transaction, we should construct the package
2568                         // assuming it gets confirmed in the next block. Sadly, we have code which considers
2569                         // "not yet confirmed" things as discardable, so we cannot do that here.
2570                         let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2571                         let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2572                         if !new_outputs.is_empty() {
2573                                 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2574                         }
2575                         claimable_outpoints.append(&mut new_outpoints);
2576                 }
2577
2578                 // Find which on-chain events have reached their confirmation threshold.
2579                 let onchain_events_awaiting_threshold_conf =
2580                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
2581                 let mut onchain_events_reaching_threshold_conf = Vec::new();
2582                 for entry in onchain_events_awaiting_threshold_conf {
2583                         if entry.has_reached_confirmation_threshold(&self.best_block) {
2584                                 onchain_events_reaching_threshold_conf.push(entry);
2585                         } else {
2586                                 self.onchain_events_awaiting_threshold_conf.push(entry);
2587                         }
2588                 }
2589
2590                 // Used to check for duplicate HTLC resolutions.
2591                 #[cfg(debug_assertions)]
2592                 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
2593                         .iter()
2594                         .filter_map(|entry| match &entry.event {
2595                                 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
2596                                 _ => None,
2597                         })
2598                         .collect();
2599                 #[cfg(debug_assertions)]
2600                 let mut matured_htlcs = Vec::new();
2601
2602                 // Produce actionable events from on-chain events having reached their threshold.
2603                 for entry in onchain_events_reaching_threshold_conf.drain(..) {
2604                         match entry.event {
2605                                 OnchainEvent::HTLCUpdate { ref source, payment_hash, htlc_value_satoshis, commitment_tx_output_idx } => {
2606                                         // Check for duplicate HTLC resolutions.
2607                                         #[cfg(debug_assertions)]
2608                                         {
2609                                                 debug_assert!(
2610                                                         unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
2611                                                         "An unmature HTLC transaction conflicts with a maturing one; failed to \
2612                                                          call either transaction_unconfirmed for the conflicting transaction \
2613                                                          or block_disconnected for a block containing it.");
2614                                                 debug_assert!(
2615                                                         matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
2616                                                         "A matured HTLC transaction conflicts with a maturing one; failed to \
2617                                                          call either transaction_unconfirmed for the conflicting transaction \
2618                                                          or block_disconnected for a block containing it.");
2619                                                 matured_htlcs.push(source.clone());
2620                                         }
2621
2622                                         log_debug!(logger, "HTLC {} failure update in {} has got enough confirmations to be passed upstream",
2623                                                 log_bytes!(payment_hash.0), entry.txid);
2624                                         self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2625                                                 payment_hash,
2626                                                 payment_preimage: None,
2627                                                 source: source.clone(),
2628                                                 htlc_value_satoshis,
2629                                         }));
2630                                         if let Some(idx) = commitment_tx_output_idx {
2631                                                 self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { commitment_tx_output_idx: idx, payment_preimage: None });
2632                                         }
2633                                 },
2634                                 OnchainEvent::MaturingOutput { descriptor } => {
2635                                         log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2636                                         self.pending_events.push(Event::SpendableOutputs {
2637                                                 outputs: vec![descriptor]
2638                                         });
2639                                 },
2640                                 OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
2641                                         self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { commitment_tx_output_idx, payment_preimage: preimage });
2642                                 },
2643                                 OnchainEvent::FundingSpendConfirmation { .. } => {
2644                                         self.funding_spend_confirmed = Some(entry.txid);
2645                                 },
2646                         }
2647                 }
2648
2649                 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
2650
2651                 // Determine new outputs to watch by comparing against previously known outputs to watch,
2652                 // updating the latter in the process.
2653                 watch_outputs.retain(|&(ref txid, ref txouts)| {
2654                         let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2655                         self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2656                 });
2657                 #[cfg(test)]
2658                 {
2659                         // If we see a transaction for which we registered outputs previously,
2660                         // make sure the registered scriptpubkey at the expected index match
2661                         // the actual transaction output one. We failed this case before #653.
2662                         for tx in &txn_matched {
2663                                 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2664                                         for idx_and_script in outputs.iter() {
2665                                                 assert!((idx_and_script.0 as usize) < tx.output.len());
2666                                                 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2667                                         }
2668                                 }
2669                         }
2670                 }
2671                 watch_outputs
2672         }
2673
2674         pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2675                 where B::Target: BroadcasterInterface,
2676                       F::Target: FeeEstimator,
2677                       L::Target: Logger,
2678         {
2679                 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
2680
2681                 //We may discard:
2682                 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2683                 //- maturing spendable output has transaction paying us has been disconnected
2684                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
2685
2686                 let bounded_fee_estimator = LowerBoundedFeeEstimator::new(fee_estimator);
2687                 self.onchain_tx_handler.block_disconnected(height, broadcaster, &bounded_fee_estimator, logger);
2688
2689                 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
2690         }
2691
2692         fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
2693                 &mut self,
2694                 txid: &Txid,
2695                 broadcaster: B,
2696                 fee_estimator: &LowerBoundedFeeEstimator<F>,
2697                 logger: L,
2698         ) where
2699                 B::Target: BroadcasterInterface,
2700                 F::Target: FeeEstimator,
2701                 L::Target: Logger,
2702         {
2703                 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| if entry.txid == *txid {
2704                         log_info!(logger, "Removing onchain event with txid {}", txid);
2705                         false
2706                 } else { true });
2707                 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
2708         }
2709
2710         /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2711         /// transactions thereof.
2712         fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2713                 let mut matched_txn = HashSet::new();
2714                 txdata.iter().filter(|&&(_, tx)| {
2715                         let mut matches = self.spends_watched_output(tx);
2716                         for input in tx.input.iter() {
2717                                 if matches { break; }
2718                                 if matched_txn.contains(&input.previous_output.txid) {
2719                                         matches = true;
2720                                 }
2721                         }
2722                         if matches {
2723                                 matched_txn.insert(tx.txid());
2724                         }
2725                         matches
2726                 }).map(|(_, tx)| *tx).collect()
2727         }
2728
2729         /// Checks if a given transaction spends any watched outputs.
2730         fn spends_watched_output(&self, tx: &Transaction) -> bool {
2731                 for input in tx.input.iter() {
2732                         if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2733                                 for (idx, _script_pubkey) in outputs.iter() {
2734                                         if *idx == input.previous_output.vout {
2735                                                 #[cfg(test)]
2736                                                 {
2737                                                         // If the expected script is a known type, check that the witness
2738                                                         // appears to be spending the correct type (ie that the match would
2739                                                         // actually succeed in BIP 158/159-style filters).
2740                                                         if _script_pubkey.is_v0_p2wsh() {
2741                                                                 if input.witness.last().unwrap().to_vec() == deliberately_bogus_accepted_htlc_witness_program() {
2742                                                                         // In at least one test we use a deliberately bogus witness
2743                                                                         // script which hit an old panic. Thus, we check for that here
2744                                                                         // and avoid the assert if its the expected bogus script.
2745                                                                         return true;
2746                                                                 }
2747
2748                                                                 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().to_vec()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2749                                                         } else if _script_pubkey.is_v0_p2wpkh() {
2750                                                                 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2751                                                         } else { panic!(); }
2752                                                 }
2753                                                 return true;
2754                                         }
2755                                 }
2756                         }
2757                 }
2758
2759                 false
2760         }
2761
2762         fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
2763                 // We need to consider all HTLCs which are:
2764                 //  * in any unrevoked counterparty commitment transaction, as they could broadcast said
2765                 //    transactions and we'd end up in a race, or
2766                 //  * are in our latest holder commitment transaction, as this is the thing we will
2767                 //    broadcast if we go on-chain.
2768                 // Note that we consider HTLCs which were below dust threshold here - while they don't
2769                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2770                 // to the source, and if we don't fail the channel we will have to ensure that the next
2771                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2772                 // easier to just fail the channel as this case should be rare enough anyway.
2773                 let height = self.best_block.height();
2774                 macro_rules! scan_commitment {
2775                         ($htlcs: expr, $holder_tx: expr) => {
2776                                 for ref htlc in $htlcs {
2777                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2778                                         // chain with enough room to claim the HTLC without our counterparty being able to
2779                                         // time out the HTLC first.
2780                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2781                                         // concern is being able to claim the corresponding inbound HTLC (on another
2782                                         // channel) before it expires. In fact, we don't even really care if our
2783                                         // counterparty here claims such an outbound HTLC after it expired as long as we
2784                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2785                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2786                                         // we give ourselves a few blocks of headroom after expiration before going
2787                                         // on-chain for an expired HTLC.
2788                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2789                                         // from us until we've reached the point where we go on-chain with the
2790                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2791                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2792                                         //  aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2793                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
2794                                         //      outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2795                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2796                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2797                                         //      LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2798                                         //  The final, above, condition is checked for statically in channelmanager
2799                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
2800                                         let htlc_outbound = $holder_tx == htlc.offered;
2801                                         if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2802                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2803                                                 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2804                                                 return true;
2805                                         }
2806                                 }
2807                         }
2808                 }
2809
2810                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2811
2812                 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2813                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2814                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2815                         }
2816                 }
2817                 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2818                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2819                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2820                         }
2821                 }
2822
2823                 false
2824         }
2825
2826         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2827         /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2828         fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2829                 'outer_loop: for input in &tx.input {
2830                         let mut payment_data = None;
2831                         let witness_items = input.witness.len();
2832                         let htlctype = input.witness.last().map(|w| w.len()).and_then(HTLCType::scriptlen_to_htlctype);
2833                         let prev_last_witness_len = input.witness.second_to_last().map(|w| w.len()).unwrap_or(0);
2834                         let revocation_sig_claim = (witness_items == 3 && htlctype == Some(HTLCType::OfferedHTLC) && prev_last_witness_len == 33)
2835                                 || (witness_items == 3 && htlctype == Some(HTLCType::AcceptedHTLC) && prev_last_witness_len == 33);
2836                         let accepted_preimage_claim = witness_items == 5 && htlctype == Some(HTLCType::AcceptedHTLC)
2837                                 && input.witness.second_to_last().unwrap().len() == 32;
2838                         #[cfg(not(fuzzing))]
2839                         let accepted_timeout_claim = witness_items == 3 && htlctype == Some(HTLCType::AcceptedHTLC) && !revocation_sig_claim;
2840                         let offered_preimage_claim = witness_items == 3 && htlctype == Some(HTLCType::OfferedHTLC) &&
2841                                 !revocation_sig_claim && input.witness.second_to_last().unwrap().len() == 32;
2842
2843                         #[cfg(not(fuzzing))]
2844                         let offered_timeout_claim = witness_items == 5 && htlctype == Some(HTLCType::OfferedHTLC);
2845
2846                         let mut payment_preimage = PaymentPreimage([0; 32]);
2847                         if accepted_preimage_claim {
2848                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
2849                         } else if offered_preimage_claim {
2850                                 payment_preimage.0.copy_from_slice(input.witness.second_to_last().unwrap());
2851                         }
2852
2853                         macro_rules! log_claim {
2854                                 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2855                                         let outbound_htlc = $holder_tx == $htlc.offered;
2856                                         // HTLCs must either be claimed by a matching script type or through the
2857                                         // revocation path:
2858                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2859                                         debug_assert!(!$htlc.offered || offered_preimage_claim || offered_timeout_claim || revocation_sig_claim);
2860                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2861                                         debug_assert!($htlc.offered || accepted_preimage_claim || accepted_timeout_claim || revocation_sig_claim);
2862                                         // Further, only exactly one of the possible spend paths should have been
2863                                         // matched by any HTLC spend:
2864                                         #[cfg(not(fuzzing))] // Note that the fuzzer is not bound by pesky things like "signatures"
2865                                         debug_assert_eq!(accepted_preimage_claim as u8 + accepted_timeout_claim as u8 +
2866                                                          offered_preimage_claim as u8 + offered_timeout_claim as u8 +
2867                                                          revocation_sig_claim as u8, 1);
2868                                         if ($holder_tx && revocation_sig_claim) ||
2869                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2870                                                 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2871                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2872                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2873                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2874                                         } else {
2875                                                 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2876                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2877                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2878                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2879                                         }
2880                                 }
2881                         }
2882
2883                         macro_rules! check_htlc_valid_counterparty {
2884                                 ($counterparty_txid: expr, $htlc_output: expr) => {
2885                                         if let Some(txid) = $counterparty_txid {
2886                                                 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2887                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2888                                                                 if let &Some(ref source) = pending_source {
2889                                                                         log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2890                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
2891                                                                         break;
2892                                                                 }
2893                                                         }
2894                                                 }
2895                                         }
2896                                 }
2897                         }
2898
2899                         macro_rules! scan_commitment {
2900                                 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2901                                         for (ref htlc_output, source_option) in $htlcs {
2902                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2903                                                         if let Some(ref source) = source_option {
2904                                                                 log_claim!($tx_info, $holder_tx, htlc_output, true);
2905                                                                 // We have a resolution of an HTLC either from one of our latest
2906                                                                 // holder commitment transactions or an unrevoked counterparty commitment
2907                                                                 // transaction. This implies we either learned a preimage, the HTLC
2908                                                                 // has timed out, or we screwed up. In any case, we should now
2909                                                                 // resolve the source HTLC with the original sender.
2910                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
2911                                                         } else if !$holder_tx {
2912                                                                 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2913                                                                 if payment_data.is_none() {
2914                                                                         check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2915                                                                 }
2916                                                         }
2917                                                         if payment_data.is_none() {
2918                                                                 log_claim!($tx_info, $holder_tx, htlc_output, false);
2919                                                                 let outbound_htlc = $holder_tx == htlc_output.offered;
2920                                                                 if !outbound_htlc || revocation_sig_claim {
2921                                                                         self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2922                                                                                 txid: tx.txid(), height,
2923                                                                                 event: OnchainEvent::HTLCSpendConfirmation {
2924                                                                                         commitment_tx_output_idx: input.previous_output.vout,
2925                                                                                         preimage: if accepted_preimage_claim || offered_preimage_claim {
2926                                                                                                 Some(payment_preimage) } else { None },
2927                                                                                         // If this is a payment to us (!outbound_htlc, above),
2928                                                                                         // wait for the CSV delay before dropping the HTLC from
2929                                                                                         // claimable balance if the claim was an HTLC-Success
2930                                                                                         // transaction.
2931                                                                                         on_to_local_output_csv: if accepted_preimage_claim {
2932                                                                                                 Some(self.on_holder_tx_csv) } else { None },
2933                                                                                 },
2934                                                                         });
2935                                                                 } else {
2936                                                                         // Outbound claims should always have payment_data, unless
2937                                                                         // we've already failed the HTLC as the commitment transaction
2938                                                                         // which was broadcasted was revoked. In that case, we should
2939                                                                         // spend the HTLC output here immediately, and expose that fact
2940                                                                         // as a Balance, something which we do not yet do.
2941                                                                         // TODO: Track the above as claimable!
2942                                                                 }
2943                                                                 continue 'outer_loop;
2944                                                         }
2945                                                 }
2946                                         }
2947                                 }
2948                         }
2949
2950                         if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2951                                 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2952                                         "our latest holder commitment tx", true);
2953                         }
2954                         if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2955                                 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2956                                         scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2957                                                 "our previous holder commitment tx", true);
2958                                 }
2959                         }
2960                         if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2961                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2962                                         "counterparty commitment tx", false);
2963                         }
2964
2965                         // Check that scan_commitment, above, decided there is some source worth relaying an
2966                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2967                         if let Some((source, payment_hash, amount_msat)) = payment_data {
2968                                 if accepted_preimage_claim {
2969                                         if !self.pending_monitor_events.iter().any(
2970                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2971                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2972                                                         txid: tx.txid(),
2973                                                         height,
2974                                                         event: OnchainEvent::HTLCSpendConfirmation {
2975                                                                 commitment_tx_output_idx: input.previous_output.vout,
2976                                                                 preimage: Some(payment_preimage),
2977                                                                 on_to_local_output_csv: None,
2978                                                         },
2979                                                 });
2980                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2981                                                         source,
2982                                                         payment_preimage: Some(payment_preimage),
2983                                                         payment_hash,
2984                                                         htlc_value_satoshis: Some(amount_msat / 1000),
2985                                                 }));
2986                                         }
2987                                 } else if offered_preimage_claim {
2988                                         if !self.pending_monitor_events.iter().any(
2989                                                 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2990                                                         upd.source == source
2991                                                 } else { false }) {
2992                                                 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
2993                                                         txid: tx.txid(),
2994                                                         height,
2995                                                         event: OnchainEvent::HTLCSpendConfirmation {
2996                                                                 commitment_tx_output_idx: input.previous_output.vout,
2997                                                                 preimage: Some(payment_preimage),
2998                                                                 on_to_local_output_csv: None,
2999                                                         },
3000                                                 });
3001                                                 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
3002                                                         source,
3003                                                         payment_preimage: Some(payment_preimage),
3004                                                         payment_hash,
3005                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3006                                                 }));
3007                                         }
3008                                 } else {
3009                                         self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
3010                                                 if entry.height != height { return true; }
3011                                                 match entry.event {
3012                                                         OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
3013                                                                 *htlc_source != source
3014                                                         },
3015                                                         _ => true,
3016                                                 }
3017                                         });
3018                                         let entry = OnchainEventEntry {
3019                                                 txid: tx.txid(),
3020                                                 height,
3021                                                 event: OnchainEvent::HTLCUpdate {
3022                                                         source, payment_hash,
3023                                                         htlc_value_satoshis: Some(amount_msat / 1000),
3024                                                         commitment_tx_output_idx: Some(input.previous_output.vout),
3025                                                 },
3026                                         };
3027                                         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());
3028                                         self.onchain_events_awaiting_threshold_conf.push(entry);
3029                                 }
3030                         }
3031                 }
3032         }
3033
3034         /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
3035         fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
3036                 let mut spendable_output = None;
3037                 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
3038                         if i > ::core::u16::MAX as usize {
3039                                 // While it is possible that an output exists on chain which is greater than the
3040                                 // 2^16th output in a given transaction, this is only possible if the output is not
3041                                 // in a lightning transaction and was instead placed there by some third party who
3042                                 // wishes to give us money for no reason.
3043                                 // Namely, any lightning transactions which we pre-sign will never have anywhere
3044                                 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
3045                                 // scripts are not longer than one byte in length and because they are inherently
3046                                 // non-standard due to their size.
3047                                 // Thus, it is completely safe to ignore such outputs, and while it may result in
3048                                 // us ignoring non-lightning fund to us, that is only possible if someone fills
3049                                 // nearly a full block with garbage just to hit this case.
3050                                 continue;
3051                         }
3052                         if outp.script_pubkey == self.destination_script {
3053                                 spendable_output =  Some(SpendableOutputDescriptor::StaticOutput {
3054                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3055                                         output: outp.clone(),
3056                                 });
3057                                 break;
3058                         }
3059                         if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
3060                                 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
3061                                         spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
3062                                                 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3063                                                 per_commitment_point: broadcasted_holder_revokable_script.1,
3064                                                 to_self_delay: self.on_holder_tx_csv,
3065                                                 output: outp.clone(),
3066                                                 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
3067                                                 channel_keys_id: self.channel_keys_id,
3068                                                 channel_value_satoshis: self.channel_value_satoshis,
3069                                         }));
3070                                         break;
3071                                 }
3072                         }
3073                         if self.counterparty_payment_script == outp.script_pubkey {
3074                                 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
3075                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3076                                         output: outp.clone(),
3077                                         channel_keys_id: self.channel_keys_id,
3078                                         channel_value_satoshis: self.channel_value_satoshis,
3079                                 }));
3080                                 break;
3081                         }
3082                         if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
3083                                 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
3084                                         outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
3085                                         output: outp.clone(),
3086                                 });
3087                                 break;
3088                         }
3089                 }
3090                 if let Some(spendable_output) = spendable_output {
3091                         let entry = OnchainEventEntry {
3092                                 txid: tx.txid(),
3093                                 height: height,
3094                                 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
3095                         };
3096                         log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
3097                         self.onchain_events_awaiting_threshold_conf.push(entry);
3098                 }
3099         }
3100 }
3101
3102 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
3103 where
3104         T::Target: BroadcasterInterface,
3105         F::Target: FeeEstimator,
3106         L::Target: Logger,
3107 {
3108         fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3109                 self.0.block_connected(header, txdata, height, &*self.1, &*self.2, &*self.3);
3110         }
3111
3112         fn block_disconnected(&self, header: &BlockHeader, height: u32) {
3113                 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
3114         }
3115 }
3116
3117 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
3118 where
3119         T::Target: BroadcasterInterface,
3120         F::Target: FeeEstimator,
3121         L::Target: Logger,
3122 {
3123         fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
3124                 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
3125         }
3126
3127         fn transaction_unconfirmed(&self, txid: &Txid) {
3128                 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
3129         }
3130
3131         fn best_block_updated(&self, header: &BlockHeader, height: u32) {
3132                 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
3133         }
3134
3135         fn get_relevant_txids(&self) -> Vec<Txid> {
3136                 self.0.get_relevant_txids()
3137         }
3138 }
3139
3140 const MAX_ALLOC_SIZE: usize = 64*1024;
3141
3142 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
3143                 for (BlockHash, ChannelMonitor<Signer>) {
3144         fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
3145                 macro_rules! unwrap_obj {
3146                         ($key: expr) => {
3147                                 match $key {
3148                                         Ok(res) => res,
3149                                         Err(_) => return Err(DecodeError::InvalidValue),
3150                                 }
3151                         }
3152                 }
3153
3154                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
3155
3156                 let latest_update_id: u64 = Readable::read(reader)?;
3157                 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
3158
3159                 let destination_script = Readable::read(reader)?;
3160                 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
3161                         0 => {
3162                                 let revokable_address = Readable::read(reader)?;
3163                                 let per_commitment_point = Readable::read(reader)?;
3164                                 let revokable_script = Readable::read(reader)?;
3165                                 Some((revokable_address, per_commitment_point, revokable_script))
3166                         },
3167                         1 => { None },
3168                         _ => return Err(DecodeError::InvalidValue),
3169                 };
3170                 let counterparty_payment_script = Readable::read(reader)?;
3171                 let shutdown_script = {
3172                         let script = <Script as Readable>::read(reader)?;
3173                         if script.is_empty() { None } else { Some(script) }
3174                 };
3175
3176                 let channel_keys_id = Readable::read(reader)?;
3177                 let holder_revocation_basepoint = Readable::read(reader)?;
3178                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
3179                 // barely-init'd ChannelMonitors that we can't do anything with.
3180                 let outpoint = OutPoint {
3181                         txid: Readable::read(reader)?,
3182                         index: Readable::read(reader)?,
3183                 };
3184                 let funding_info = (outpoint, Readable::read(reader)?);
3185                 let current_counterparty_commitment_txid = Readable::read(reader)?;
3186                 let prev_counterparty_commitment_txid = Readable::read(reader)?;
3187
3188                 let counterparty_commitment_params = Readable::read(reader)?;
3189                 let funding_redeemscript = Readable::read(reader)?;
3190                 let channel_value_satoshis = Readable::read(reader)?;
3191
3192                 let their_cur_per_commitment_points = {
3193                         let first_idx = <U48 as Readable>::read(reader)?.0;
3194                         if first_idx == 0 {
3195                                 None
3196                         } else {
3197                                 let first_point = Readable::read(reader)?;
3198                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
3199                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
3200                                         Some((first_idx, first_point, None))
3201                                 } else {
3202                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
3203                                 }
3204                         }
3205                 };
3206
3207                 let on_holder_tx_csv: u16 = Readable::read(reader)?;
3208
3209                 let commitment_secrets = Readable::read(reader)?;
3210
3211                 macro_rules! read_htlc_in_commitment {
3212                         () => {
3213                                 {
3214                                         let offered: bool = Readable::read(reader)?;
3215                                         let amount_msat: u64 = Readable::read(reader)?;
3216                                         let cltv_expiry: u32 = Readable::read(reader)?;
3217                                         let payment_hash: PaymentHash = Readable::read(reader)?;
3218                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
3219
3220                                         HTLCOutputInCommitment {
3221                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
3222                                         }
3223                                 }
3224                         }
3225                 }
3226
3227                 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
3228                 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
3229                 for _ in 0..counterparty_claimable_outpoints_len {
3230                         let txid: Txid = Readable::read(reader)?;
3231                         let htlcs_count: u64 = Readable::read(reader)?;
3232                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
3233                         for _ in 0..htlcs_count {
3234                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
3235                         }
3236                         if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
3237                                 return Err(DecodeError::InvalidValue);
3238                         }
3239                 }
3240
3241                 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
3242                 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
3243                 for _ in 0..counterparty_commitment_txn_on_chain_len {
3244                         let txid: Txid = Readable::read(reader)?;
3245                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3246                         if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
3247                                 return Err(DecodeError::InvalidValue);
3248                         }
3249                 }
3250
3251                 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
3252                 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
3253                 for _ in 0..counterparty_hash_commitment_number_len {
3254                         let payment_hash: PaymentHash = Readable::read(reader)?;
3255                         let commitment_number = <U48 as Readable>::read(reader)?.0;
3256                         if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
3257                                 return Err(DecodeError::InvalidValue);
3258                         }
3259                 }
3260
3261                 let mut prev_holder_signed_commitment_tx: Option<HolderSignedTx> =
3262                         match <u8 as Readable>::read(reader)? {
3263                                 0 => None,
3264                                 1 => {
3265                                         Some(Readable::read(reader)?)
3266                                 },
3267                                 _ => return Err(DecodeError::InvalidValue),
3268                         };
3269                 let mut current_holder_commitment_tx: HolderSignedTx = Readable::read(reader)?;
3270
3271                 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
3272                 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
3273
3274                 let payment_preimages_len: u64 = Readable::read(reader)?;
3275                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
3276                 for _ in 0..payment_preimages_len {
3277                         let preimage: PaymentPreimage = Readable::read(reader)?;
3278                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3279                         if let Some(_) = payment_preimages.insert(hash, preimage) {
3280                                 return Err(DecodeError::InvalidValue);
3281                         }
3282                 }
3283
3284                 let pending_monitor_events_len: u64 = Readable::read(reader)?;
3285                 let mut pending_monitor_events = Some(
3286                         Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3))));
3287                 for _ in 0..pending_monitor_events_len {
3288                         let ev = match <u8 as Readable>::read(reader)? {
3289                                 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
3290                                 1 => MonitorEvent::CommitmentTxConfirmed(funding_info.0),
3291                                 _ => return Err(DecodeError::InvalidValue)
3292                         };
3293                         pending_monitor_events.as_mut().unwrap().push(ev);
3294                 }
3295
3296                 let pending_events_len: u64 = Readable::read(reader)?;
3297                 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
3298                 for _ in 0..pending_events_len {
3299                         if let Some(event) = MaybeReadable::read(reader)? {
3300                                 pending_events.push(event);
3301                         }
3302                 }
3303
3304                 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
3305
3306                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
3307                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
3308                 for _ in 0..waiting_threshold_conf_len {
3309                         if let Some(val) = MaybeReadable::read(reader)? {
3310                                 onchain_events_awaiting_threshold_conf.push(val);
3311                         }
3312                 }
3313
3314                 let outputs_to_watch_len: u64 = Readable::read(reader)?;
3315                 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>>())));
3316                 for _ in 0..outputs_to_watch_len {
3317                         let txid = Readable::read(reader)?;
3318                         let outputs_len: u64 = Readable::read(reader)?;
3319                         let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
3320                         for _ in 0..outputs_len {
3321                                 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
3322                         }
3323                         if let Some(_) = outputs_to_watch.insert(txid, outputs) {
3324                                 return Err(DecodeError::InvalidValue);
3325                         }
3326                 }
3327                 let onchain_tx_handler: OnchainTxHandler<Signer> = ReadableArgs::read(reader, keys_manager)?;
3328
3329                 let lockdown_from_offchain = Readable::read(reader)?;
3330                 let holder_tx_signed = Readable::read(reader)?;
3331
3332                 if let Some(prev_commitment_tx) = prev_holder_signed_commitment_tx.as_mut() {
3333                         let prev_holder_value = onchain_tx_handler.get_prev_holder_commitment_to_self_value();
3334                         if prev_holder_value.is_none() { return Err(DecodeError::InvalidValue); }
3335                         if prev_commitment_tx.to_self_value_sat == u64::max_value() {
3336                                 prev_commitment_tx.to_self_value_sat = prev_holder_value.unwrap();
3337                         } else if prev_commitment_tx.to_self_value_sat != prev_holder_value.unwrap() {
3338                                 return Err(DecodeError::InvalidValue);
3339                         }
3340                 }
3341
3342                 let cur_holder_value = onchain_tx_handler.get_cur_holder_commitment_to_self_value();
3343                 if current_holder_commitment_tx.to_self_value_sat == u64::max_value() {
3344                         current_holder_commitment_tx.to_self_value_sat = cur_holder_value;
3345                 } else if current_holder_commitment_tx.to_self_value_sat != cur_holder_value {
3346                         return Err(DecodeError::InvalidValue);
3347                 }
3348
3349                 let mut funding_spend_confirmed = None;
3350                 let mut htlcs_resolved_on_chain = Some(Vec::new());
3351                 let mut funding_spend_seen = Some(false);
3352                 let mut counterparty_node_id = None;
3353                 read_tlv_fields!(reader, {
3354                         (1, funding_spend_confirmed, option),
3355                         (3, htlcs_resolved_on_chain, vec_type),
3356                         (5, pending_monitor_events, vec_type),
3357                         (7, funding_spend_seen, option),
3358                         (9, counterparty_node_id, option),
3359                 });
3360
3361                 let mut secp_ctx = Secp256k1::new();
3362                 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
3363
3364                 Ok((best_block.block_hash(), ChannelMonitor {
3365                         inner: Mutex::new(ChannelMonitorImpl {
3366                                 latest_update_id,
3367                                 commitment_transaction_number_obscure_factor,
3368
3369                                 destination_script,
3370                                 broadcasted_holder_revokable_script,
3371                                 counterparty_payment_script,
3372                                 shutdown_script,
3373
3374                                 channel_keys_id,
3375                                 holder_revocation_basepoint,
3376                                 funding_info,
3377                                 current_counterparty_commitment_txid,
3378                                 prev_counterparty_commitment_txid,
3379
3380                                 counterparty_commitment_params,
3381                                 funding_redeemscript,
3382                                 channel_value_satoshis,
3383                                 their_cur_per_commitment_points,
3384
3385                                 on_holder_tx_csv,
3386
3387                                 commitment_secrets,
3388                                 counterparty_claimable_outpoints,
3389                                 counterparty_commitment_txn_on_chain,
3390                                 counterparty_hash_commitment_number,
3391
3392                                 prev_holder_signed_commitment_tx,
3393                                 current_holder_commitment_tx,
3394                                 current_counterparty_commitment_number,
3395                                 current_holder_commitment_number,
3396
3397                                 payment_preimages,
3398                                 pending_monitor_events: pending_monitor_events.unwrap(),
3399                                 pending_events,
3400
3401                                 onchain_events_awaiting_threshold_conf,
3402                                 outputs_to_watch,
3403
3404                                 onchain_tx_handler,
3405
3406                                 lockdown_from_offchain,
3407                                 holder_tx_signed,
3408                                 funding_spend_seen: funding_spend_seen.unwrap(),
3409                                 funding_spend_confirmed,
3410                                 htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
3411
3412                                 best_block,
3413                                 counterparty_node_id,
3414
3415                                 secp_ctx,
3416                         }),
3417                 }))
3418         }
3419 }
3420
3421 #[cfg(test)]
3422 mod tests {
3423         use bitcoin::blockdata::block::BlockHeader;
3424         use bitcoin::blockdata::script::{Script, Builder};
3425         use bitcoin::blockdata::opcodes;
3426         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, EcdsaSighashType};
3427         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
3428         use bitcoin::util::sighash;
3429         use bitcoin::hashes::Hash;
3430         use bitcoin::hashes::sha256::Hash as Sha256;
3431         use bitcoin::hashes::hex::FromHex;
3432         use bitcoin::hash_types::{BlockHash, Txid};
3433         use bitcoin::network::constants::Network;
3434         use bitcoin::secp256k1::{SecretKey,PublicKey};
3435         use bitcoin::secp256k1::Secp256k1;
3436
3437         use hex;
3438
3439         use crate::chain::chaininterface::LowerBoundedFeeEstimator;
3440
3441         use super::ChannelMonitorUpdateStep;
3442         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};
3443         use chain::{BestBlock, Confirm};
3444         use chain::channelmonitor::ChannelMonitor;
3445         use chain::package::{weight_offered_htlc, weight_received_htlc, weight_revoked_offered_htlc, weight_revoked_received_htlc, WEIGHT_REVOKED_OUTPUT};
3446         use chain::transaction::OutPoint;
3447         use chain::keysinterface::InMemorySigner;
3448         use ln::{PaymentPreimage, PaymentHash};
3449         use ln::chan_utils;
3450         use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
3451         use ln::channelmanager::PaymentSendFailure;
3452         use ln::features::InitFeatures;
3453         use ln::functional_test_utils::*;
3454         use ln::script::ShutdownScript;
3455         use util::errors::APIError;
3456         use util::events::{ClosureReason, MessageSendEventsProvider};
3457         use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
3458         use util::ser::{ReadableArgs, Writeable};
3459         use sync::{Arc, Mutex};
3460         use io;
3461         use bitcoin::Witness;
3462         use prelude::*;
3463
3464         fn do_test_funding_spend_refuses_updates(use_local_txn: bool) {
3465                 // Previously, monitor updates were allowed freely even after a funding-spend transaction
3466                 // confirmed. This would allow a race condition where we could receive a payment (including
3467                 // the counterparty revoking their broadcasted state!) and accept it without recourse as
3468                 // long as the ChannelMonitor receives the block first, the full commitment update dance
3469                 // occurs after the block is connected, and before the ChannelManager receives the block.
3470                 // Obviously this is an incredibly contrived race given the counterparty would be risking
3471                 // their full channel balance for it, but its worth fixing nonetheless as it makes the
3472                 // potential ChannelMonitor states simpler to reason about.
3473                 //
3474                 // This test checks said behavior, as well as ensuring a ChannelMonitorUpdate with multiple
3475                 // updates is handled correctly in such conditions.
3476                 let chanmon_cfgs = create_chanmon_cfgs(3);
3477                 let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
3478                 let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
3479                 let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
3480                 let channel = create_announced_chan_between_nodes(
3481                         &nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
3482                 create_announced_chan_between_nodes(
3483                         &nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
3484
3485                 // Rebalance somewhat
3486                 send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
3487
3488                 // First route two payments for testing at the end
3489                 let payment_preimage_1 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
3490                 let payment_preimage_2 = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1_000_000).0;
3491
3492                 let local_txn = get_local_commitment_txn!(nodes[1], channel.2);
3493                 assert_eq!(local_txn.len(), 1);
3494                 let remote_txn = get_local_commitment_txn!(nodes[0], channel.2);
3495                 assert_eq!(remote_txn.len(), 3); // Commitment and two HTLC-Timeouts
3496                 check_spends!(remote_txn[1], remote_txn[0]);
3497                 check_spends!(remote_txn[2], remote_txn[0]);
3498                 let broadcast_tx = if use_local_txn { &local_txn[0] } else { &remote_txn[0] };
3499
3500                 // Connect a commitment transaction, but only to the ChainMonitor/ChannelMonitor. The
3501                 // channel is now closed, but the ChannelManager doesn't know that yet.
3502                 let new_header = BlockHeader {
3503                         version: 2, time: 0, bits: 0, nonce: 0,
3504                         prev_blockhash: nodes[0].best_block_info().0,
3505                         merkle_root: Default::default() };
3506                 let conf_height = nodes[0].best_block_info().1 + 1;
3507                 nodes[1].chain_monitor.chain_monitor.transactions_confirmed(&new_header,
3508                         &[(0, broadcast_tx)], conf_height);
3509
3510                 let (_, pre_update_monitor) = <(BlockHash, ChannelMonitor<InMemorySigner>)>::read(
3511                                                 &mut io::Cursor::new(&get_monitor!(nodes[1], channel.2).encode()),
3512                                                 &nodes[1].keys_manager.backing).unwrap();
3513
3514                 // If the ChannelManager tries to update the channel, however, the ChainMonitor will pass
3515                 // the update through to the ChannelMonitor which will refuse it (as the channel is closed).
3516                 let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[1], nodes[0], 100_000);
3517                 unwrap_send_err!(nodes[1].node.send_payment(&route, payment_hash, &Some(payment_secret)),
3518                         true, APIError::ChannelUnavailable { ref err },
3519                         assert!(err.contains("ChannelMonitor storage failure")));
3520                 check_added_monitors!(nodes[1], 2); // After the failure we generate a close-channel monitor update
3521                 check_closed_broadcast!(nodes[1], true);
3522                 check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError { err: "ChannelMonitor storage failure".to_string() });
3523
3524                 // Build a new ChannelMonitorUpdate which contains both the failing commitment tx update
3525                 // and provides the claim preimages for the two pending HTLCs. The first update generates
3526                 // an error, but the point of this test is to ensure the later updates are still applied.
3527                 let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
3528                 let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().skip(1).next().unwrap().clone();
3529                 assert_eq!(replay_update.updates.len(), 1);
3530                 if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
3531                 } else { panic!(); }
3532                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_1 });
3533                 replay_update.updates.push(ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage: payment_preimage_2 });
3534
3535                 let broadcaster = TestBroadcaster::new(Arc::clone(&nodes[1].blocks));
3536                 assert!(
3537                         pre_update_monitor.update_monitor(&replay_update, &&broadcaster, &&chanmon_cfgs[1].fee_estimator, &nodes[1].logger)
3538                         .is_err());
3539                 // Even though we error'd on the first update, we should still have generated an HTLC claim
3540                 // transaction
3541                 let txn_broadcasted = broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
3542                 assert!(txn_broadcasted.len() >= 2);
3543                 let htlc_txn = txn_broadcasted.iter().filter(|tx| {
3544                         assert_eq!(tx.input.len(), 1);
3545                         tx.input[0].previous_output.txid == broadcast_tx.txid()
3546                 }).collect::<Vec<_>>();
3547                 assert_eq!(htlc_txn.len(), 2);
3548                 check_spends!(htlc_txn[0], broadcast_tx);
3549                 check_spends!(htlc_txn[1], broadcast_tx);
3550         }
3551         #[test]
3552         fn test_funding_spend_refuses_updates() {
3553                 do_test_funding_spend_refuses_updates(true);
3554                 do_test_funding_spend_refuses_updates(false);
3555         }
3556
3557         #[test]
3558         fn test_prune_preimages() {
3559                 let secp_ctx = Secp256k1::new();
3560                 let logger = Arc::new(TestLogger::new());
3561                 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
3562                 let fee_estimator = TestFeeEstimator { sat_per_kw: Mutex::new(253) };
3563
3564                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3565                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3566
3567                 let mut preimages = Vec::new();
3568                 {
3569                         for i in 0..20 {
3570                                 let preimage = PaymentPreimage([i; 32]);
3571                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
3572                                 preimages.push((preimage, hash));
3573                         }
3574                 }
3575
3576                 macro_rules! preimages_slice_to_htlc_outputs {
3577                         ($preimages_slice: expr) => {
3578                                 {
3579                                         let mut res = Vec::new();
3580                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
3581                                                 res.push((HTLCOutputInCommitment {
3582                                                         offered: true,
3583                                                         amount_msat: 0,
3584                                                         cltv_expiry: 0,
3585                                                         payment_hash: preimage.1.clone(),
3586                                                         transaction_output_index: Some(idx as u32),
3587                                                 }, None));
3588                                         }
3589                                         res
3590                                 }
3591                         }
3592                 }
3593                 macro_rules! preimages_to_holder_htlcs {
3594                         ($preimages_slice: expr) => {
3595                                 {
3596                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
3597                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
3598                                         res
3599                                 }
3600                         }
3601                 }
3602
3603                 macro_rules! test_preimages_exist {
3604                         ($preimages_slice: expr, $monitor: expr) => {
3605                                 for preimage in $preimages_slice {
3606                                         assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
3607                                 }
3608                         }
3609                 }
3610
3611                 let keys = InMemorySigner::new(
3612                         &secp_ctx,
3613                         SecretKey::from_slice(&[41; 32]).unwrap(),
3614                         SecretKey::from_slice(&[41; 32]).unwrap(),
3615                         SecretKey::from_slice(&[41; 32]).unwrap(),
3616                         SecretKey::from_slice(&[41; 32]).unwrap(),
3617                         SecretKey::from_slice(&[41; 32]).unwrap(),
3618                         SecretKey::from_slice(&[41; 32]).unwrap(),
3619                         [41; 32],
3620                         0,
3621                         [0; 32]
3622                 );
3623
3624                 let counterparty_pubkeys = ChannelPublicKeys {
3625                         funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
3626                         revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
3627                         payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
3628                         delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
3629                         htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
3630                 };
3631                 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
3632                 let channel_parameters = ChannelTransactionParameters {
3633                         holder_pubkeys: keys.holder_channel_pubkeys.clone(),
3634                         holder_selected_contest_delay: 66,
3635                         is_outbound_from_holder: true,
3636                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
3637                                 pubkeys: counterparty_pubkeys,
3638                                 selected_contest_delay: 67,
3639                         }),
3640                         funding_outpoint: Some(funding_outpoint),
3641                         opt_anchors: None,
3642                 };
3643                 // Prune with one old state and a holder commitment tx holding a few overlaps with the
3644                 // old state.
3645                 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
3646                 let best_block = BestBlock::from_genesis(Network::Testnet);
3647                 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
3648                                                   Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
3649                                                   (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
3650                                                   &channel_parameters,
3651                                                   Script::new(), 46, 0,
3652                                                   HolderCommitmentTransaction::dummy(), best_block, dummy_key);
3653
3654                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
3655                 let dummy_txid = dummy_tx.txid();
3656                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
3657                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
3658                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
3659                 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
3660                 for &(ref preimage, ref hash) in preimages.iter() {
3661                         let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_estimator);
3662                         monitor.provide_payment_preimage(hash, preimage, &broadcaster, &bounded_fee_estimator, &logger);
3663                 }
3664
3665                 // Now provide a secret, pruning preimages 10-15
3666                 let mut secret = [0; 32];
3667                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
3668                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
3669                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
3670                 test_preimages_exist!(&preimages[0..10], monitor);
3671                 test_preimages_exist!(&preimages[15..20], monitor);
3672
3673                 // Now provide a further secret, pruning preimages 15-17
3674                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
3675                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
3676                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
3677                 test_preimages_exist!(&preimages[0..10], monitor);
3678                 test_preimages_exist!(&preimages[17..20], monitor);
3679
3680                 // Now update holder commitment tx info, pruning only element 18 as we still care about the
3681                 // previous commitment tx's preimages too
3682                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
3683                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
3684                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
3685                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
3686                 test_preimages_exist!(&preimages[0..10], monitor);
3687                 test_preimages_exist!(&preimages[18..20], monitor);
3688
3689                 // But if we do it again, we'll prune 5-10
3690                 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
3691                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
3692                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
3693                 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
3694                 test_preimages_exist!(&preimages[0..5], monitor);
3695         }
3696
3697         #[test]
3698         fn test_claim_txn_weight_computation() {
3699                 // We test Claim txn weight, knowing that we want expected weigth and
3700                 // not actual case to avoid sigs and time-lock delays hell variances.
3701
3702                 let secp_ctx = Secp256k1::new();
3703                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
3704                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
3705
3706                 macro_rules! sign_input {
3707                         ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr, $opt_anchors: expr) => {
3708                                 let htlc = HTLCOutputInCommitment {
3709                                         offered: if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_offered_htlc($opt_anchors) { true } else { false },
3710                                         amount_msat: 0,
3711                                         cltv_expiry: 2 << 16,
3712                                         payment_hash: PaymentHash([1; 32]),
3713                                         transaction_output_index: Some($idx as u32),
3714                                 };
3715                                 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, $opt_anchors, &pubkey, &pubkey, &pubkey) };
3716                                 let sighash = hash_to_message!(&$sighash_parts.segwit_signature_hash($idx, &redeem_script, $amount, EcdsaSighashType::All).unwrap()[..]);
3717                                 let sig = secp_ctx.sign_ecdsa(&sighash, &privkey);
3718                                 let mut ser_sig = sig.serialize_der().to_vec();
3719                                 ser_sig.push(EcdsaSighashType::All as u8);
3720                                 $sum_actual_sigs += ser_sig.len();
3721                                 let witness = $sighash_parts.witness_mut($idx).unwrap();
3722                                 witness.push(ser_sig);
3723                                 if *$weight == WEIGHT_REVOKED_OUTPUT {
3724                                         witness.push(vec!(1));
3725                                 } else if *$weight == weight_revoked_offered_htlc($opt_anchors) || *$weight == weight_revoked_received_htlc($opt_anchors) {
3726                                         witness.push(pubkey.clone().serialize().to_vec());
3727                                 } else if *$weight == weight_received_htlc($opt_anchors) {
3728                                         witness.push(vec![0]);
3729                                 } else {
3730                                         witness.push(PaymentPreimage([1; 32]).0.to_vec());
3731                                 }
3732                                 witness.push(redeem_script.into_bytes());
3733                                 let witness = witness.to_vec();
3734                                 println!("witness[0] {}", witness[0].len());
3735                                 println!("witness[1] {}", witness[1].len());
3736                                 println!("witness[2] {}", witness[2].len());
3737                         }
3738                 }
3739
3740                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
3741                 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
3742
3743                 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
3744                 for &opt_anchors in [false, true].iter() {
3745                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3746                         let mut sum_actual_sigs = 0;
3747                         for i in 0..4 {
3748                                 claim_tx.input.push(TxIn {
3749                                         previous_output: BitcoinOutPoint {
3750                                                 txid,
3751                                                 vout: i,
3752                                         },
3753                                         script_sig: Script::new(),
3754                                         sequence: 0xfffffffd,
3755                                         witness: Witness::new(),
3756                                 });
3757                         }
3758                         claim_tx.output.push(TxOut {
3759                                 script_pubkey: script_pubkey.clone(),
3760                                 value: 0,
3761                         });
3762                         let base_weight = claim_tx.weight();
3763                         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)];
3764                         let mut inputs_total_weight = 2; // count segwit flags
3765                         {
3766                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3767                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3768                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3769                                         inputs_total_weight += inp;
3770                                 }
3771                         }
3772                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3773                 }
3774
3775                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3776                 for &opt_anchors in [false, true].iter() {
3777                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3778                         let mut sum_actual_sigs = 0;
3779                         for i in 0..4 {
3780                                 claim_tx.input.push(TxIn {
3781                                         previous_output: BitcoinOutPoint {
3782                                                 txid,
3783                                                 vout: i,
3784                                         },
3785                                         script_sig: Script::new(),
3786                                         sequence: 0xfffffffd,
3787                                         witness: Witness::new(),
3788                                 });
3789                         }
3790                         claim_tx.output.push(TxOut {
3791                                 script_pubkey: script_pubkey.clone(),
3792                                 value: 0,
3793                         });
3794                         let base_weight = claim_tx.weight();
3795                         let inputs_weight = vec![weight_offered_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors), weight_received_htlc(opt_anchors)];
3796                         let mut inputs_total_weight = 2; // count segwit flags
3797                         {
3798                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3799                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3800                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3801                                         inputs_total_weight += inp;
3802                                 }
3803                         }
3804                         assert_eq!(base_weight + inputs_total_weight as usize,  claim_tx.weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3805                 }
3806
3807                 // Justice tx with 1 revoked HTLC-Success tx output
3808                 for &opt_anchors in [false, true].iter() {
3809                         let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3810                         let mut sum_actual_sigs = 0;
3811                         claim_tx.input.push(TxIn {
3812                                 previous_output: BitcoinOutPoint {
3813                                         txid,
3814                                         vout: 0,
3815                                 },
3816                                 script_sig: Script::new(),
3817                                 sequence: 0xfffffffd,
3818                                 witness: Witness::new(),
3819                         });
3820                         claim_tx.output.push(TxOut {
3821                                 script_pubkey: script_pubkey.clone(),
3822                                 value: 0,
3823                         });
3824                         let base_weight = claim_tx.weight();
3825                         let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
3826                         let mut inputs_total_weight = 2; // count segwit flags
3827                         {
3828                                 let mut sighash_parts = sighash::SighashCache::new(&mut claim_tx);
3829                                 for (idx, inp) in inputs_weight.iter().enumerate() {
3830                                         sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs, opt_anchors);
3831                                         inputs_total_weight += inp;
3832                                 }
3833                         }
3834                         assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
3835                 }
3836         }
3837
3838         // Further testing is done in the ChannelManager integration tests.
3839 }