1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
13 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
14 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
15 //! be made in responding to certain messages, see [`chain::Watch`] for more.
17 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
18 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
19 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
20 //! security-domain-separated system design, you should consider having multiple paths for
21 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
23 use bitcoin::blockdata::block::{Block, BlockHeader};
24 use bitcoin::blockdata::transaction::{TxOut,Transaction};
25 use bitcoin::blockdata::script::{Script, Builder};
26 use bitcoin::blockdata::opcodes;
28 use bitcoin::hashes::Hash;
29 use bitcoin::hashes::sha256::Hash as Sha256;
30 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
32 use bitcoin::secp256k1::{Secp256k1,Signature};
33 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
34 use bitcoin::secp256k1;
36 use ln::{PaymentHash, PaymentPreimage};
37 use ln::msgs::DecodeError;
39 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
40 use ln::channelmanager::HTLCSource;
42 use chain::{BestBlock, WatchedOutput};
43 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
44 use chain::transaction::{OutPoint, TransactionData};
45 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
46 use chain::onchaintx::OnchainTxHandler;
47 use chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput};
49 use util::logger::Logger;
50 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48, OptionDeserWrapper};
52 use util::events::Event;
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, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
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.
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.
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.
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
88 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
90 impl Writeable for ChannelMonitorUpdate {
91 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::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)?;
98 write_tlv_fields!(w, {});
102 impl Readable for ChannelMonitorUpdate {
103 fn read<R: ::std::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>()));
109 updates.push(Readable::read(r)?);
111 read_tlv_fields!(r, {});
112 Ok(Self { update_id, updates })
116 /// An error enum representing a failure to persist a channel monitor update.
117 #[derive(Clone, Copy, Debug, PartialEq)]
118 pub enum ChannelMonitorUpdateErr {
119 /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
120 /// our state failed, but is expected to succeed at some point in the future).
122 /// Such a failure will "freeze" a channel, preventing us from revoking old states or
123 /// submitting new commitment transactions to the counterparty. Once the update(s) which failed
124 /// have been successfully applied, ChannelManager::channel_monitor_updated can be used to
125 /// restore the channel to an operational state.
127 /// Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
128 /// you return a TemporaryFailure you must ensure that it is written to disk safely before
129 /// writing out the latest ChannelManager state.
131 /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
132 /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
133 /// to claim it on this channel) and those updates must be applied wherever they can be. At
134 /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
135 /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
136 /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
139 /// Note that even if updates made after TemporaryFailure succeed you must still call
140 /// channel_monitor_updated to ensure you have the latest monitor and re-enable normal channel
143 /// Note that the update being processed here will not be replayed for you when you call
144 /// ChannelManager::channel_monitor_updated, so you must store the update itself along
145 /// with the persisted ChannelMonitor on your own local disk prior to returning a
146 /// TemporaryFailure. You may, of course, employ a journaling approach, storing only the
147 /// ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
150 /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
151 /// remote location (with local copies persisted immediately), it is anticipated that all
152 /// updates will return TemporaryFailure until the remote copies could be updated.
154 /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
155 /// different watchtower and cannot update with all watchtowers that were previously informed
156 /// of this channel).
158 /// At reception of this error, ChannelManager will force-close the channel and return at
159 /// least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
160 /// least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
161 /// update must be rejected.
163 /// This failure may also signal a failure to update the local persisted copy of one of
164 /// the channel monitor instance.
166 /// Note that even when you fail a holder commitment transaction update, you must store the
167 /// update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
168 /// broadcasts it (e.g distributed channel-monitor deployment)
170 /// In case of distributed watchtowers deployment, the new version must be written to disk, as
171 /// state may have been stored but rejected due to a block forcing a commitment broadcast. This
172 /// storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
173 /// lagging behind on block processing.
177 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
178 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::update_monitor this
179 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
181 /// Contains a developer-readable error message.
182 #[derive(Clone, Debug)]
183 pub struct MonitorUpdateError(pub &'static str);
185 /// An event to be processed by the ChannelManager.
186 #[derive(Clone, PartialEq)]
187 pub enum MonitorEvent {
188 /// A monitor event containing an HTLCUpdate.
189 HTLCEvent(HTLCUpdate),
191 /// A monitor event that the Channel's commitment transaction was broadcasted.
192 CommitmentTxBroadcasted(OutPoint),
195 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
196 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
197 /// preimage claim backward will lead to loss of funds.
198 #[derive(Clone, PartialEq)]
199 pub struct HTLCUpdate {
200 pub(crate) payment_hash: PaymentHash,
201 pub(crate) payment_preimage: Option<PaymentPreimage>,
202 pub(crate) source: HTLCSource
204 impl_writeable_tlv_based!(HTLCUpdate, {
205 (0, payment_hash, required),
206 (2, source, required),
207 (4, payment_preimage, option),
210 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
211 /// instead claiming it in its own individual transaction.
212 pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
213 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
214 /// HTLC-Success transaction.
215 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
216 /// transaction confirmed (and we use it in a few more, equivalent, places).
217 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
218 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
219 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
220 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
221 /// at CLTV expiration height but giving a grace period to our peer may be profitable for us if he
222 /// can provide an over-late preimage. Nevertheless, grace period has to be accounted in our
223 /// CLTV_EXPIRY_DELTA to be secure. Following this policy we may decrease the rate of channel failures
224 /// due to expiration but increase the cost of funds being locked longuer in case of failure.
225 /// This delay also cover a low-power peer being slow to process blocks and so being behind us on
226 /// accurate block height.
227 /// In case of onchain failure to be pass backward we may see the last block of ANTI_REORG_DELAY
228 /// with at worst this delay, so we are not only using this value as a mercy for them but also
229 /// us as a safeguard to delay with enough time.
230 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
231 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
232 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
233 // We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
234 // It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
235 // solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
236 // keep bumping another claim tx to solve the outpoint.
237 pub const ANTI_REORG_DELAY: u32 = 6;
238 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
239 /// refuse to accept a new HTLC.
241 /// This is used for a few separate purposes:
242 /// 1) if we've received an MPP HTLC to us and it expires within this many blocks and we are
243 /// waiting on additional parts (or waiting on the preimage for any HTLC from the user), we will
245 /// 2) if we receive an HTLC within this many blocks of its expiry (plus one to avoid a race
246 /// condition with the above), we will fail this HTLC without telling the user we received it,
247 /// 3) if we are waiting on a connection or a channel state update to send an HTLC to a peer, and
248 /// that HTLC expires within this many blocks, we will simply fail the HTLC instead.
250 /// (1) is all about protecting us - we need enough time to update the channel state before we hit
251 /// CLTV_CLAIM_BUFFER, at which point we'd go on chain to claim the HTLC with the preimage.
253 /// (2) is the same, but with an additional buffer to avoid accepting an HTLC which is immediately
254 /// in a race condition between the user connecting a block (which would fail it) and the user
255 /// providing us the preimage (which would claim it).
257 /// (3) is about our counterparty - we don't want to relay an HTLC to a counterparty when they may
258 /// end up force-closing the channel on us to claim it.
259 pub(crate) const HTLC_FAIL_BACK_BUFFER: u32 = CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS;
261 // TODO(devrandom) replace this with HolderCommitmentTransaction
262 #[derive(Clone, PartialEq)]
263 struct HolderSignedTx {
264 /// txid of the transaction in tx, just used to make comparison faster
266 revocation_key: PublicKey,
267 a_htlc_key: PublicKey,
268 b_htlc_key: PublicKey,
269 delayed_payment_key: PublicKey,
270 per_commitment_point: PublicKey,
272 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
274 impl_writeable_tlv_based!(HolderSignedTx, {
276 (2, revocation_key, required),
277 (4, a_htlc_key, required),
278 (6, b_htlc_key, required),
279 (8, delayed_payment_key, required),
280 (10, per_commitment_point, required),
281 (12, feerate_per_kw, required),
282 (14, htlc_outputs, vec_type)
285 /// We use this to track counterparty commitment transactions and htlcs outputs and
286 /// use it to generate any justice or 2nd-stage preimage/timeout transactions.
288 struct CounterpartyCommitmentTransaction {
289 counterparty_delayed_payment_base_key: PublicKey,
290 counterparty_htlc_base_key: PublicKey,
291 on_counterparty_tx_csv: u16,
292 per_htlc: HashMap<Txid, Vec<HTLCOutputInCommitment>>
295 impl Writeable for CounterpartyCommitmentTransaction {
296 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
297 w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
298 for (ref txid, ref htlcs) in self.per_htlc.iter() {
299 w.write_all(&txid[..])?;
300 w.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
301 for &ref htlc in htlcs.iter() {
305 write_tlv_fields!(w, {
306 (0, self.counterparty_delayed_payment_base_key, required),
307 (2, self.counterparty_htlc_base_key, required),
308 (4, self.on_counterparty_tx_csv, required),
313 impl Readable for CounterpartyCommitmentTransaction {
314 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
315 let counterparty_commitment_transaction = {
316 let per_htlc_len: u64 = Readable::read(r)?;
317 let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
318 for _ in 0..per_htlc_len {
319 let txid: Txid = Readable::read(r)?;
320 let htlcs_count: u64 = Readable::read(r)?;
321 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
322 for _ in 0..htlcs_count {
323 let htlc = Readable::read(r)?;
326 if let Some(_) = per_htlc.insert(txid, htlcs) {
327 return Err(DecodeError::InvalidValue);
330 let mut counterparty_delayed_payment_base_key = OptionDeserWrapper(None);
331 let mut counterparty_htlc_base_key = OptionDeserWrapper(None);
332 let mut on_counterparty_tx_csv: u16 = 0;
333 read_tlv_fields!(r, {
334 (0, counterparty_delayed_payment_base_key, required),
335 (2, counterparty_htlc_base_key, required),
336 (4, on_counterparty_tx_csv, required),
338 CounterpartyCommitmentTransaction {
339 counterparty_delayed_payment_base_key: counterparty_delayed_payment_base_key.0.unwrap(),
340 counterparty_htlc_base_key: counterparty_htlc_base_key.0.unwrap(),
341 on_counterparty_tx_csv,
345 Ok(counterparty_commitment_transaction)
349 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
350 /// transaction causing it.
352 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
354 struct OnchainEventEntry {
360 impl OnchainEventEntry {
361 fn confirmation_threshold(&self) -> u32 {
362 let mut conf_threshold = self.height + ANTI_REORG_DELAY - 1;
363 if let OnchainEvent::MaturingOutput {
364 descriptor: SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor)
366 // A CSV'd transaction is confirmable in block (input height) + CSV delay, which means
367 // it's broadcastable when we see the previous block.
368 conf_threshold = cmp::max(conf_threshold, self.height + descriptor.to_self_delay as u32 - 1);
373 fn has_reached_confirmation_threshold(&self, best_block: &BestBlock) -> bool {
374 best_block.height() >= self.confirmation_threshold()
378 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
379 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
382 /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
383 /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
384 /// only win from it, so it's never an OnchainEvent
387 payment_hash: PaymentHash,
390 descriptor: SpendableOutputDescriptor,
394 impl_writeable_tlv_based!(OnchainEventEntry, {
396 (2, height, required),
397 (4, event, required),
400 impl_writeable_tlv_based_enum!(OnchainEvent,
402 (0, source, required),
403 (2, payment_hash, required),
405 (1, MaturingOutput) => {
406 (0, descriptor, required),
410 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
412 pub(crate) enum ChannelMonitorUpdateStep {
413 LatestHolderCommitmentTXInfo {
414 commitment_tx: HolderCommitmentTransaction,
415 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
417 LatestCounterpartyCommitmentTXInfo {
418 commitment_txid: Txid,
419 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
420 commitment_number: u64,
421 their_revocation_point: PublicKey,
424 payment_preimage: PaymentPreimage,
430 /// Used to indicate that the no future updates will occur, and likely that the latest holder
431 /// commitment transaction(s) should be broadcast, as the channel has been force-closed.
433 /// If set to false, we shouldn't broadcast the latest holder commitment transaction as we
434 /// think we've fallen behind!
435 should_broadcast: bool,
439 impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep,
440 (0, LatestHolderCommitmentTXInfo) => {
441 (0, commitment_tx, required),
442 (2, htlc_outputs, vec_type),
444 (1, LatestCounterpartyCommitmentTXInfo) => {
445 (0, commitment_txid, required),
446 (2, commitment_number, required),
447 (4, their_revocation_point, required),
448 (6, htlc_outputs, vec_type),
450 (2, PaymentPreimage) => {
451 (0, payment_preimage, required),
453 (3, CommitmentSecret) => {
455 (2, secret, required),
457 (4, ChannelForceClosed) => {
458 (0, should_broadcast, required),
462 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
463 /// on-chain transactions to ensure no loss of funds occurs.
465 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
466 /// information and are actively monitoring the chain.
468 /// Pending Events or updated HTLCs which have not yet been read out by
469 /// get_and_clear_pending_monitor_events or get_and_clear_pending_events are serialized to disk and
470 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
471 /// gotten are fully handled before re-serializing the new state.
473 /// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
474 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
475 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
476 /// returned block hash and the the current chain and then reconnecting blocks to get to the
477 /// best chain) upon deserializing the object!
478 pub struct ChannelMonitor<Signer: Sign> {
480 pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
482 inner: Mutex<ChannelMonitorImpl<Signer>>,
485 pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
486 latest_update_id: u64,
487 commitment_transaction_number_obscure_factor: u64,
489 destination_script: Script,
490 broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
491 counterparty_payment_script: Script,
492 shutdown_script: Option<Script>,
494 channel_keys_id: [u8; 32],
495 holder_revocation_basepoint: PublicKey,
496 funding_info: (OutPoint, Script),
497 current_counterparty_commitment_txid: Option<Txid>,
498 prev_counterparty_commitment_txid: Option<Txid>,
500 counterparty_tx_cache: CounterpartyCommitmentTransaction,
501 funding_redeemscript: Script,
502 channel_value_satoshis: u64,
503 // first is the idx of the first of the two revocation points
504 their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
506 on_holder_tx_csv: u16,
508 commitment_secrets: CounterpartyCommitmentSecrets,
509 counterparty_claimable_outpoints: HashMap<Txid, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
510 /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
511 /// Nor can we figure out their commitment numbers without the commitment transaction they are
512 /// spending. Thus, in order to claim them via revocation key, we track all the counterparty
513 /// commitment transactions which we find on-chain, mapping them to the commitment number which
514 /// can be used to derive the revocation key and claim the transactions.
515 counterparty_commitment_txn_on_chain: HashMap<Txid, u64>,
516 /// Cache used to make pruning of payment_preimages faster.
517 /// Maps payment_hash values to commitment numbers for counterparty transactions for non-revoked
518 /// counterparty transactions (ie should remain pretty small).
519 /// Serialized to disk but should generally not be sent to Watchtowers.
520 counterparty_hash_commitment_number: HashMap<PaymentHash, u64>,
522 // We store two holder commitment transactions to avoid any race conditions where we may update
523 // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
524 // various monitors for one channel being out of sync, and us broadcasting a holder
525 // transaction for which we have deleted claim information on some watchtowers.
526 prev_holder_signed_commitment_tx: Option<HolderSignedTx>,
527 current_holder_commitment_tx: HolderSignedTx,
529 // Used just for ChannelManager to make sure it has the latest channel data during
531 current_counterparty_commitment_number: u64,
532 // Used just for ChannelManager to make sure it has the latest channel data during
534 current_holder_commitment_number: u64,
536 payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
538 pending_monitor_events: Vec<MonitorEvent>,
539 pending_events: Vec<Event>,
541 // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
542 // which to take actions once they reach enough confirmations. Each entry includes the
543 // transaction's id and the height when the transaction was confirmed on chain.
544 onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
546 // If we get serialized out and re-read, we need to make sure that the chain monitoring
547 // interface knows about the TXOs that we want to be notified of spends of. We could probably
548 // be smart and derive them from the above storage fields, but its much simpler and more
549 // Obviously Correct (tm) if we just keep track of them explicitly.
550 outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
553 pub onchain_tx_handler: OnchainTxHandler<Signer>,
555 onchain_tx_handler: OnchainTxHandler<Signer>,
557 // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
558 // channel has been force-closed. After this is set, no further holder commitment transaction
559 // updates may occur, and we panic!() if one is provided.
560 lockdown_from_offchain: bool,
562 // Set once we've signed a holder commitment transaction and handed it over to our
563 // OnchainTxHandler. After this is set, no future updates to our holder commitment transactions
564 // may occur, and we fail any such monitor updates.
566 // In case of update rejection due to a locally already signed commitment transaction, we
567 // nevertheless store update content to track in case of concurrent broadcast by another
568 // remote monitor out-of-order with regards to the block view.
569 holder_tx_signed: bool,
571 // We simply modify best_block in Channel's block_connected so that serialization is
572 // consistent but hopefully the users' copy handles block_connected in a consistent way.
573 // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
574 // their best_block from its state and not based on updated copies that didn't run through
575 // the full block_connected).
576 best_block: BestBlock,
578 secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
581 /// Transaction outputs to watch for on-chain spends.
582 pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
584 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
585 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
586 /// underlying object
587 impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
588 fn eq(&self, other: &Self) -> bool {
589 let inner = self.inner.lock().unwrap();
590 let other = other.inner.lock().unwrap();
595 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
596 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
597 /// underlying object
598 impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
599 fn eq(&self, other: &Self) -> bool {
600 if self.latest_update_id != other.latest_update_id ||
601 self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
602 self.destination_script != other.destination_script ||
603 self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
604 self.counterparty_payment_script != other.counterparty_payment_script ||
605 self.channel_keys_id != other.channel_keys_id ||
606 self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
607 self.funding_info != other.funding_info ||
608 self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
609 self.prev_counterparty_commitment_txid != other.prev_counterparty_commitment_txid ||
610 self.counterparty_tx_cache != other.counterparty_tx_cache ||
611 self.funding_redeemscript != other.funding_redeemscript ||
612 self.channel_value_satoshis != other.channel_value_satoshis ||
613 self.their_cur_revocation_points != other.their_cur_revocation_points ||
614 self.on_holder_tx_csv != other.on_holder_tx_csv ||
615 self.commitment_secrets != other.commitment_secrets ||
616 self.counterparty_claimable_outpoints != other.counterparty_claimable_outpoints ||
617 self.counterparty_commitment_txn_on_chain != other.counterparty_commitment_txn_on_chain ||
618 self.counterparty_hash_commitment_number != other.counterparty_hash_commitment_number ||
619 self.prev_holder_signed_commitment_tx != other.prev_holder_signed_commitment_tx ||
620 self.current_counterparty_commitment_number != other.current_counterparty_commitment_number ||
621 self.current_holder_commitment_number != other.current_holder_commitment_number ||
622 self.current_holder_commitment_tx != other.current_holder_commitment_tx ||
623 self.payment_preimages != other.payment_preimages ||
624 self.pending_monitor_events != other.pending_monitor_events ||
625 self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
626 self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
627 self.outputs_to_watch != other.outputs_to_watch ||
628 self.lockdown_from_offchain != other.lockdown_from_offchain ||
629 self.holder_tx_signed != other.holder_tx_signed
638 impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
639 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
640 self.inner.lock().unwrap().write(writer)
644 // These are also used for ChannelMonitorUpdate, above.
645 const SERIALIZATION_VERSION: u8 = 1;
646 const MIN_SERIALIZATION_VERSION: u8 = 1;
648 impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
649 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
650 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
652 self.latest_update_id.write(writer)?;
654 // Set in initial Channel-object creation, so should always be set by now:
655 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
657 self.destination_script.write(writer)?;
658 if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
659 writer.write_all(&[0; 1])?;
660 broadcasted_holder_revokable_script.0.write(writer)?;
661 broadcasted_holder_revokable_script.1.write(writer)?;
662 broadcasted_holder_revokable_script.2.write(writer)?;
664 writer.write_all(&[1; 1])?;
667 self.counterparty_payment_script.write(writer)?;
668 match &self.shutdown_script {
669 Some(script) => script.write(writer)?,
670 None => Script::new().write(writer)?,
673 self.channel_keys_id.write(writer)?;
674 self.holder_revocation_basepoint.write(writer)?;
675 writer.write_all(&self.funding_info.0.txid[..])?;
676 writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
677 self.funding_info.1.write(writer)?;
678 self.current_counterparty_commitment_txid.write(writer)?;
679 self.prev_counterparty_commitment_txid.write(writer)?;
681 self.counterparty_tx_cache.write(writer)?;
682 self.funding_redeemscript.write(writer)?;
683 self.channel_value_satoshis.write(writer)?;
685 match self.their_cur_revocation_points {
686 Some((idx, pubkey, second_option)) => {
687 writer.write_all(&byte_utils::be48_to_array(idx))?;
688 writer.write_all(&pubkey.serialize())?;
689 match second_option {
690 Some(second_pubkey) => {
691 writer.write_all(&second_pubkey.serialize())?;
694 writer.write_all(&[0; 33])?;
699 writer.write_all(&byte_utils::be48_to_array(0))?;
703 writer.write_all(&byte_utils::be16_to_array(self.on_holder_tx_csv))?;
705 self.commitment_secrets.write(writer)?;
707 macro_rules! serialize_htlc_in_commitment {
708 ($htlc_output: expr) => {
709 writer.write_all(&[$htlc_output.offered as u8; 1])?;
710 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
711 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
712 writer.write_all(&$htlc_output.payment_hash.0[..])?;
713 $htlc_output.transaction_output_index.write(writer)?;
717 writer.write_all(&byte_utils::be64_to_array(self.counterparty_claimable_outpoints.len() as u64))?;
718 for (ref txid, ref htlc_infos) in self.counterparty_claimable_outpoints.iter() {
719 writer.write_all(&txid[..])?;
720 writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
721 for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
722 serialize_htlc_in_commitment!(htlc_output);
723 htlc_source.as_ref().map(|b| b.as_ref()).write(writer)?;
727 writer.write_all(&byte_utils::be64_to_array(self.counterparty_commitment_txn_on_chain.len() as u64))?;
728 for (ref txid, commitment_number) in self.counterparty_commitment_txn_on_chain.iter() {
729 writer.write_all(&txid[..])?;
730 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
733 writer.write_all(&byte_utils::be64_to_array(self.counterparty_hash_commitment_number.len() as u64))?;
734 for (ref payment_hash, commitment_number) in self.counterparty_hash_commitment_number.iter() {
735 writer.write_all(&payment_hash.0[..])?;
736 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
739 if let Some(ref prev_holder_tx) = self.prev_holder_signed_commitment_tx {
740 writer.write_all(&[1; 1])?;
741 prev_holder_tx.write(writer)?;
743 writer.write_all(&[0; 1])?;
746 self.current_holder_commitment_tx.write(writer)?;
748 writer.write_all(&byte_utils::be48_to_array(self.current_counterparty_commitment_number))?;
749 writer.write_all(&byte_utils::be48_to_array(self.current_holder_commitment_number))?;
751 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
752 for payment_preimage in self.payment_preimages.values() {
753 writer.write_all(&payment_preimage.0[..])?;
756 writer.write_all(&byte_utils::be64_to_array(self.pending_monitor_events.len() as u64))?;
757 for event in self.pending_monitor_events.iter() {
759 MonitorEvent::HTLCEvent(upd) => {
763 MonitorEvent::CommitmentTxBroadcasted(_) => 1u8.write(writer)?
767 writer.write_all(&byte_utils::be64_to_array(self.pending_events.len() as u64))?;
768 for event in self.pending_events.iter() {
769 event.write(writer)?;
772 self.best_block.block_hash().write(writer)?;
773 writer.write_all(&byte_utils::be32_to_array(self.best_block.height()))?;
775 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
776 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
777 entry.write(writer)?;
780 (self.outputs_to_watch.len() as u64).write(writer)?;
781 for (txid, idx_scripts) in self.outputs_to_watch.iter() {
783 (idx_scripts.len() as u64).write(writer)?;
784 for (idx, script) in idx_scripts.iter() {
786 script.write(writer)?;
789 self.onchain_tx_handler.write(writer)?;
791 self.lockdown_from_offchain.write(writer)?;
792 self.holder_tx_signed.write(writer)?;
794 write_tlv_fields!(writer, {
795 (1, self.shutdown_script, option),
802 impl<Signer: Sign> ChannelMonitor<Signer> {
803 pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
804 on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
805 channel_parameters: &ChannelTransactionParameters,
806 funding_redeemscript: Script, channel_value_satoshis: u64,
807 commitment_transaction_number_obscure_factor: u64,
808 initial_holder_commitment_tx: HolderCommitmentTransaction,
809 best_block: BestBlock) -> ChannelMonitor<Signer> {
811 assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
812 let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
813 let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
815 let counterparty_channel_parameters = channel_parameters.counterparty_parameters.as_ref().unwrap();
816 let counterparty_delayed_payment_base_key = counterparty_channel_parameters.pubkeys.delayed_payment_basepoint;
817 let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
818 let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
820 let channel_keys_id = keys.channel_keys_id();
821 let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
823 // block for Rust 1.34 compat
824 let (holder_commitment_tx, current_holder_commitment_number) = {
825 let trusted_tx = initial_holder_commitment_tx.trust();
826 let txid = trusted_tx.txid();
828 let tx_keys = trusted_tx.keys();
829 let holder_commitment_tx = HolderSignedTx {
831 revocation_key: tx_keys.revocation_key,
832 a_htlc_key: tx_keys.broadcaster_htlc_key,
833 b_htlc_key: tx_keys.countersignatory_htlc_key,
834 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
835 per_commitment_point: tx_keys.per_commitment_point,
836 feerate_per_kw: trusted_tx.feerate_per_kw(),
837 htlc_outputs: Vec::new(), // There are never any HTLCs in the initial commitment transactions
839 (holder_commitment_tx, trusted_tx.commitment_number())
842 let onchain_tx_handler =
843 OnchainTxHandler::new(destination_script.clone(), keys,
844 channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
846 let mut outputs_to_watch = HashMap::new();
847 outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
850 inner: Mutex::new(ChannelMonitorImpl {
852 commitment_transaction_number_obscure_factor,
854 destination_script: destination_script.clone(),
855 broadcasted_holder_revokable_script: None,
856 counterparty_payment_script,
860 holder_revocation_basepoint,
862 current_counterparty_commitment_txid: None,
863 prev_counterparty_commitment_txid: None,
865 counterparty_tx_cache,
866 funding_redeemscript,
867 channel_value_satoshis,
868 their_cur_revocation_points: None,
870 on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
872 commitment_secrets: CounterpartyCommitmentSecrets::new(),
873 counterparty_claimable_outpoints: HashMap::new(),
874 counterparty_commitment_txn_on_chain: HashMap::new(),
875 counterparty_hash_commitment_number: HashMap::new(),
877 prev_holder_signed_commitment_tx: None,
878 current_holder_commitment_tx: holder_commitment_tx,
879 current_counterparty_commitment_number: 1 << 48,
880 current_holder_commitment_number,
882 payment_preimages: HashMap::new(),
883 pending_monitor_events: Vec::new(),
884 pending_events: Vec::new(),
886 onchain_events_awaiting_threshold_conf: Vec::new(),
891 lockdown_from_offchain: false,
892 holder_tx_signed: false,
902 fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
903 self.inner.lock().unwrap().provide_secret(idx, secret)
906 /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
907 /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
908 /// possibly future revocation/preimage information) to claim outputs where possible.
909 /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
910 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
913 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
914 commitment_number: u64,
915 their_revocation_point: PublicKey,
917 ) where L::Target: Logger {
918 self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
919 txid, htlc_outputs, commitment_number, their_revocation_point, logger)
923 fn provide_latest_holder_commitment_tx(
925 holder_commitment_tx: HolderCommitmentTransaction,
926 htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
927 ) -> Result<(), MonitorUpdateError> {
928 self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
929 holder_commitment_tx, htlc_outputs)
933 pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
935 payment_hash: &PaymentHash,
936 payment_preimage: &PaymentPreimage,
941 B::Target: BroadcasterInterface,
942 F::Target: FeeEstimator,
945 self.inner.lock().unwrap().provide_payment_preimage(
946 payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
949 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
954 B::Target: BroadcasterInterface,
957 self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
960 /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
963 /// panics if the given update is not the next update by update_id.
964 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
966 updates: &ChannelMonitorUpdate,
970 ) -> Result<(), MonitorUpdateError>
972 B::Target: BroadcasterInterface,
973 F::Target: FeeEstimator,
976 self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
979 /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
981 pub fn get_latest_update_id(&self) -> u64 {
982 self.inner.lock().unwrap().get_latest_update_id()
985 /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
986 pub fn get_funding_txo(&self) -> (OutPoint, Script) {
987 self.inner.lock().unwrap().get_funding_txo().clone()
990 /// Gets a list of txids, with their output scripts (in the order they appear in the
991 /// transaction), which we must learn about spends of via block_connected().
992 pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
993 self.inner.lock().unwrap().get_outputs_to_watch()
994 .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
997 /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
998 /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
999 /// have been registered.
1000 pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
1001 let lock = self.inner.lock().unwrap();
1002 filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
1003 for (txid, outputs) in lock.get_outputs_to_watch().iter() {
1004 for (index, script_pubkey) in outputs.iter() {
1005 assert!(*index <= u16::max_value() as u32);
1006 filter.register_output(WatchedOutput {
1008 outpoint: OutPoint { txid: *txid, index: *index as u16 },
1009 script_pubkey: script_pubkey.clone(),
1015 /// Get the list of HTLCs who's status has been updated on chain. This should be called by
1016 /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
1017 pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
1018 self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
1021 /// Gets the list of pending events which were generated by previous actions, clearing the list
1024 /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
1025 /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
1026 /// no internal locking in ChannelMonitors.
1027 pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
1028 self.inner.lock().unwrap().get_and_clear_pending_events()
1031 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1032 self.inner.lock().unwrap().get_min_seen_secret()
1035 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1036 self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
1039 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1040 self.inner.lock().unwrap().get_cur_holder_commitment_number()
1043 /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
1044 /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
1045 /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
1046 /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
1047 /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
1048 /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
1049 /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
1050 /// out-of-band the other node operator to coordinate with him if option is available to you.
1051 /// In any-case, choice is up to the user.
1052 pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1053 where L::Target: Logger {
1054 self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
1057 /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
1058 /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
1059 /// revoked commitment transaction.
1060 #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
1061 pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
1062 where L::Target: Logger {
1063 self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
1066 /// Processes transactions in a newly connected block, which may result in any of the following:
1067 /// - update the monitor's state against resolved HTLCs
1068 /// - punish the counterparty in the case of seeing a revoked commitment transaction
1069 /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
1070 /// - detect settled outputs for later spending
1071 /// - schedule and bump any in-flight claims
1073 /// Returns any new outputs to watch from `txdata`; after called, these are also included in
1074 /// [`get_outputs_to_watch`].
1076 /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
1077 pub fn block_connected<B: Deref, F: Deref, L: Deref>(
1079 header: &BlockHeader,
1080 txdata: &TransactionData,
1085 ) -> Vec<TransactionOutputs>
1087 B::Target: BroadcasterInterface,
1088 F::Target: FeeEstimator,
1091 self.inner.lock().unwrap().block_connected(
1092 header, txdata, height, broadcaster, fee_estimator, logger)
1095 /// Determines if the disconnected block contained any transactions of interest and updates
1097 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
1099 header: &BlockHeader,
1105 B::Target: BroadcasterInterface,
1106 F::Target: FeeEstimator,
1109 self.inner.lock().unwrap().block_disconnected(
1110 header, height, broadcaster, fee_estimator, logger)
1113 /// Processes transactions confirmed in a block with the given header and height, returning new
1114 /// outputs to watch. See [`block_connected`] for details.
1116 /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1117 /// blocks. See [`chain::Confirm`] for calling expectations.
1119 /// [`block_connected`]: Self::block_connected
1120 pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1122 header: &BlockHeader,
1123 txdata: &TransactionData,
1128 ) -> Vec<TransactionOutputs>
1130 B::Target: BroadcasterInterface,
1131 F::Target: FeeEstimator,
1134 self.inner.lock().unwrap().transactions_confirmed(
1135 header, txdata, height, broadcaster, fee_estimator, logger)
1138 /// Processes a transaction that was reorganized out of the chain.
1140 /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
1141 /// than blocks. See [`chain::Confirm`] for calling expectations.
1143 /// [`block_disconnected`]: Self::block_disconnected
1144 pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
1151 B::Target: BroadcasterInterface,
1152 F::Target: FeeEstimator,
1155 self.inner.lock().unwrap().transaction_unconfirmed(
1156 txid, broadcaster, fee_estimator, logger);
1159 /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
1160 /// [`block_connected`] for details.
1162 /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
1163 /// blocks. See [`chain::Confirm`] for calling expectations.
1165 /// [`block_connected`]: Self::block_connected
1166 pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1168 header: &BlockHeader,
1173 ) -> Vec<TransactionOutputs>
1175 B::Target: BroadcasterInterface,
1176 F::Target: FeeEstimator,
1179 self.inner.lock().unwrap().best_block_updated(
1180 header, height, broadcaster, fee_estimator, logger)
1183 /// Returns the set of txids that should be monitored for re-organization out of the chain.
1184 pub fn get_relevant_txids(&self) -> Vec<Txid> {
1185 let inner = self.inner.lock().unwrap();
1186 let mut txids: Vec<Txid> = inner.onchain_events_awaiting_threshold_conf
1188 .map(|entry| entry.txid)
1189 .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
1191 txids.sort_unstable();
1196 /// Gets the latest best block which was connected either via the [`chain::Listen`] or
1197 /// [`chain::Confirm`] interfaces.
1198 pub fn current_best_block(&self) -> BestBlock {
1199 self.inner.lock().unwrap().best_block.clone()
1203 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
1204 /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
1205 /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
1206 /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
1207 fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
1208 if let Err(()) = self.commitment_secrets.provide_secret(idx, secret) {
1209 return Err(MonitorUpdateError("Previous secret did not match new one"));
1212 // Prune HTLCs from the previous counterparty commitment tx so we don't generate failure/fulfill
1213 // events for now-revoked/fulfilled HTLCs.
1214 if let Some(txid) = self.prev_counterparty_commitment_txid.take() {
1215 for &mut (_, ref mut source) in self.counterparty_claimable_outpoints.get_mut(&txid).unwrap() {
1220 if !self.payment_preimages.is_empty() {
1221 let cur_holder_signed_commitment_tx = &self.current_holder_commitment_tx;
1222 let prev_holder_signed_commitment_tx = self.prev_holder_signed_commitment_tx.as_ref();
1223 let min_idx = self.get_min_seen_secret();
1224 let counterparty_hash_commitment_number = &mut self.counterparty_hash_commitment_number;
1226 self.payment_preimages.retain(|&k, _| {
1227 for &(ref htlc, _, _) in cur_holder_signed_commitment_tx.htlc_outputs.iter() {
1228 if k == htlc.payment_hash {
1232 if let Some(prev_holder_commitment_tx) = prev_holder_signed_commitment_tx {
1233 for &(ref htlc, _, _) in prev_holder_commitment_tx.htlc_outputs.iter() {
1234 if k == htlc.payment_hash {
1239 let contains = if let Some(cn) = counterparty_hash_commitment_number.get(&k) {
1246 counterparty_hash_commitment_number.remove(&k);
1255 pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
1256 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
1257 // so that a remote monitor doesn't learn anything unless there is a malicious close.
1258 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
1260 for &(ref htlc, _) in &htlc_outputs {
1261 self.counterparty_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
1264 log_trace!(logger, "Tracking new counterparty commitment transaction with txid {} at commitment number {} with {} HTLC outputs", txid, commitment_number, htlc_outputs.len());
1265 self.prev_counterparty_commitment_txid = self.current_counterparty_commitment_txid.take();
1266 self.current_counterparty_commitment_txid = Some(txid);
1267 self.counterparty_claimable_outpoints.insert(txid, htlc_outputs.clone());
1268 self.current_counterparty_commitment_number = commitment_number;
1269 //TODO: Merge this into the other per-counterparty-transaction output storage stuff
1270 match self.their_cur_revocation_points {
1271 Some(old_points) => {
1272 if old_points.0 == commitment_number + 1 {
1273 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
1274 } else if old_points.0 == commitment_number + 2 {
1275 if let Some(old_second_point) = old_points.2 {
1276 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
1278 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1281 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1285 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
1288 let mut htlcs = Vec::with_capacity(htlc_outputs.len());
1289 for htlc in htlc_outputs {
1290 if htlc.0.transaction_output_index.is_some() {
1294 self.counterparty_tx_cache.per_htlc.insert(txid, htlcs);
1297 /// Informs this monitor of the latest holder (ie broadcastable) commitment transaction. The
1298 /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
1299 /// is important that any clones of this channel monitor (including remote clones) by kept
1300 /// up-to-date as our holder commitment transaction is updated.
1301 /// Panics if set_on_holder_tx_csv has never been called.
1302 fn provide_latest_holder_commitment_tx(&mut self, holder_commitment_tx: HolderCommitmentTransaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>) -> Result<(), MonitorUpdateError> {
1303 // block for Rust 1.34 compat
1304 let mut new_holder_commitment_tx = {
1305 let trusted_tx = holder_commitment_tx.trust();
1306 let txid = trusted_tx.txid();
1307 let tx_keys = trusted_tx.keys();
1308 self.current_holder_commitment_number = trusted_tx.commitment_number();
1311 revocation_key: tx_keys.revocation_key,
1312 a_htlc_key: tx_keys.broadcaster_htlc_key,
1313 b_htlc_key: tx_keys.countersignatory_htlc_key,
1314 delayed_payment_key: tx_keys.broadcaster_delayed_payment_key,
1315 per_commitment_point: tx_keys.per_commitment_point,
1316 feerate_per_kw: trusted_tx.feerate_per_kw(),
1320 self.onchain_tx_handler.provide_latest_holder_tx(holder_commitment_tx);
1321 mem::swap(&mut new_holder_commitment_tx, &mut self.current_holder_commitment_tx);
1322 self.prev_holder_signed_commitment_tx = Some(new_holder_commitment_tx);
1323 if self.holder_tx_signed {
1324 return Err(MonitorUpdateError("Latest holder commitment signed has already been signed, update is rejected"));
1329 /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
1330 /// commitment_tx_infos which contain the payment hash have been revoked.
1331 fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
1332 where B::Target: BroadcasterInterface,
1333 F::Target: FeeEstimator,
1336 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
1338 // If the channel is force closed, try to claim the output from this preimage.
1339 // First check if a counterparty commitment transaction has been broadcasted:
1340 macro_rules! claim_htlcs {
1341 ($commitment_number: expr, $txid: expr) => {
1342 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
1343 self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1346 if let Some(txid) = self.current_counterparty_commitment_txid {
1347 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1348 claim_htlcs!(*commitment_number, txid);
1352 if let Some(txid) = self.prev_counterparty_commitment_txid {
1353 if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
1354 claim_htlcs!(*commitment_number, txid);
1359 // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
1360 // claiming the HTLC output from each of the holder commitment transactions.
1361 // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
1362 // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
1363 // holder commitment transactions.
1364 if self.broadcasted_holder_revokable_script.is_some() {
1365 // Assume that the broadcasted commitment transaction confirmed in the current best
1366 // block. Even if not, its a reasonable metric for the bump criteria on the HTLC
1368 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
1369 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1370 if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
1371 let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx, self.best_block.height());
1372 self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, self.best_block.height(), self.best_block.height(), broadcaster, fee_estimator, logger);
1377 pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
1378 where B::Target: BroadcasterInterface,
1381 for tx in self.get_latest_holder_commitment_txn(logger).iter() {
1382 log_info!(logger, "Broadcasting local {}", log_tx!(tx));
1383 broadcaster.broadcast_transaction(tx);
1385 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
1388 pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
1389 where B::Target: BroadcasterInterface,
1390 F::Target: FeeEstimator,
1393 // ChannelMonitor updates may be applied after force close if we receive a
1394 // preimage for a broadcasted commitment transaction HTLC output that we'd
1395 // like to claim on-chain. If this is the case, we no longer have guaranteed
1396 // access to the monitor's update ID, so we use a sentinel value instead.
1397 if updates.update_id == CLOSED_CHANNEL_UPDATE_ID {
1398 match updates.updates[0] {
1399 ChannelMonitorUpdateStep::PaymentPreimage { .. } => {},
1400 _ => panic!("Attempted to apply post-force-close ChannelMonitorUpdate that wasn't providing a payment preimage"),
1402 assert_eq!(updates.updates.len(), 1);
1403 } else if self.latest_update_id + 1 != updates.update_id {
1404 panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
1406 for update in updates.updates.iter() {
1408 ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs } => {
1409 log_trace!(logger, "Updating ChannelMonitor with latest holder commitment transaction info");
1410 if self.lockdown_from_offchain { panic!(); }
1411 self.provide_latest_holder_commitment_tx(commitment_tx.clone(), htlc_outputs.clone())?
1413 ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { commitment_txid, htlc_outputs, commitment_number, their_revocation_point } => {
1414 log_trace!(logger, "Updating ChannelMonitor with latest counterparty commitment transaction info");
1415 self.provide_latest_counterparty_commitment_tx(*commitment_txid, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger)
1417 ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } => {
1418 log_trace!(logger, "Updating ChannelMonitor with payment preimage");
1419 self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage, broadcaster, fee_estimator, logger)
1421 ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } => {
1422 log_trace!(logger, "Updating ChannelMonitor with commitment secret");
1423 self.provide_secret(*idx, *secret)?
1425 ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
1426 log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
1427 self.lockdown_from_offchain = true;
1428 if *should_broadcast {
1429 self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
1430 } else if !self.holder_tx_signed {
1431 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");
1433 // If we generated a MonitorEvent::CommitmentTxBroadcasted, the ChannelManager
1434 // will still give us a ChannelForceClosed event with !should_broadcast, but we
1435 // shouldn't print the scary warning above.
1436 log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
1441 self.latest_update_id = updates.update_id;
1445 pub fn get_latest_update_id(&self) -> u64 {
1446 self.latest_update_id
1449 pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
1453 pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
1454 // If we've detected a counterparty commitment tx on chain, we must include it in the set
1455 // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
1456 // its trivial to do, double-check that here.
1457 for (txid, _) in self.counterparty_commitment_txn_on_chain.iter() {
1458 self.outputs_to_watch.get(txid).expect("Counterparty commitment txn which have been broadcast should have outputs registered");
1460 &self.outputs_to_watch
1463 pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
1464 let mut ret = Vec::new();
1465 mem::swap(&mut ret, &mut self.pending_monitor_events);
1469 pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
1470 let mut ret = Vec::new();
1471 mem::swap(&mut ret, &mut self.pending_events);
1475 /// Can only fail if idx is < get_min_seen_secret
1476 fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1477 self.commitment_secrets.get_secret(idx)
1480 pub(crate) fn get_min_seen_secret(&self) -> u64 {
1481 self.commitment_secrets.get_min_seen_secret()
1484 pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
1485 self.current_counterparty_commitment_number
1488 pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
1489 self.current_holder_commitment_number
1492 /// Attempts to claim a counterparty commitment transaction's outputs using the revocation key and
1493 /// data in counterparty_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1494 /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1495 /// HTLC-Success/HTLC-Timeout transactions.
1496 /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1497 /// revoked counterparty commitment tx
1498 fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<PackageTemplate>, TransactionOutputs) where L::Target: Logger {
1499 // Most secp and related errors trying to create keys means we have no hope of constructing
1500 // a spend transaction...so we return no transactions to broadcast
1501 let mut claimable_outpoints = Vec::new();
1502 let mut watch_outputs = Vec::new();
1504 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1505 let per_commitment_option = self.counterparty_claimable_outpoints.get(&commitment_txid);
1507 macro_rules! ignore_error {
1508 ( $thing : expr ) => {
1511 Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs))
1516 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);
1517 if commitment_number >= self.get_min_seen_secret() {
1518 let secret = self.get_secret(commitment_number).unwrap();
1519 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1520 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1521 let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.holder_revocation_basepoint));
1522 let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.counterparty_tx_cache.counterparty_delayed_payment_base_key));
1524 let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.counterparty_tx_cache.on_counterparty_tx_csv, &delayed_key);
1525 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1527 // First, process non-htlc outputs (to_holder & to_counterparty)
1528 for (idx, outp) in tx.output.iter().enumerate() {
1529 if outp.script_pubkey == revokeable_p2wsh {
1530 let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_tx_cache.counterparty_delayed_payment_base_key, self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, outp.value, self.counterparty_tx_cache.on_counterparty_tx_csv);
1531 let justice_package = PackageTemplate::build_package(commitment_txid, idx as u32, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, true, height);
1532 claimable_outpoints.push(justice_package);
1536 // Then, try to find revoked htlc outputs
1537 if let Some(ref per_commitment_data) = per_commitment_option {
1538 for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1539 if let Some(transaction_output_index) = htlc.transaction_output_index {
1540 if transaction_output_index as usize >= tx.output.len() ||
1541 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1542 return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1544 let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_tx_cache.counterparty_delayed_payment_base_key, self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone());
1545 let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, true, height);
1546 claimable_outpoints.push(justice_package);
1551 // Last, track onchain revoked commitment transaction and fail backward outgoing HTLCs as payment path is broken
1552 if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1553 // We're definitely a counterparty commitment transaction!
1554 log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
1555 for (idx, outp) in tx.output.iter().enumerate() {
1556 watch_outputs.push((idx as u32, outp.clone()));
1558 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1560 macro_rules! check_htlc_fails {
1561 ($txid: expr, $commitment_tx: expr) => {
1562 if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1563 for &(ref htlc, ref source_option) in outpoints.iter() {
1564 if let &Some(ref source) = source_option {
1565 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1566 if entry.height != height { return true; }
1568 OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1569 *update_source != **source
1574 let entry = OnchainEventEntry {
1577 event: OnchainEvent::HTLCUpdate {
1578 source: (**source).clone(),
1579 payment_hash: htlc.payment_hash.clone(),
1582 log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, entry.confirmation_threshold());
1583 self.onchain_events_awaiting_threshold_conf.push(entry);
1589 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1590 check_htlc_fails!(txid, "current");
1592 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1593 check_htlc_fails!(txid, "counterparty");
1595 // No need to check holder commitment txn, symmetric HTLCSource must be present as per-htlc data on counterparty commitment tx
1597 } else if let Some(per_commitment_data) = per_commitment_option {
1598 // While this isn't useful yet, there is a potential race where if a counterparty
1599 // revokes a state at the same time as the commitment transaction for that state is
1600 // confirmed, and the watchtower receives the block before the user, the user could
1601 // upload a new ChannelMonitor with the revocation secret but the watchtower has
1602 // already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
1603 // not being generated by the above conditional. Thus, to be safe, we go ahead and
1605 for (idx, outp) in tx.output.iter().enumerate() {
1606 watch_outputs.push((idx as u32, outp.clone()));
1608 self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
1610 log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
1612 macro_rules! check_htlc_fails {
1613 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1614 if let Some(ref latest_outpoints) = self.counterparty_claimable_outpoints.get($txid) {
1615 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1616 if let &Some(ref source) = source_option {
1617 // Check if the HTLC is present in the commitment transaction that was
1618 // broadcast, but not if it was below the dust limit, which we should
1619 // fail backwards immediately as there is no way for us to learn the
1620 // payment_preimage.
1621 // Note that if the dust limit were allowed to change between
1622 // commitment transactions we'd want to be check whether *any*
1623 // broadcastable commitment transaction has the HTLC in it, but it
1624 // cannot currently change after channel initialization, so we don't
1626 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1627 if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1631 log_trace!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of counterparty commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1632 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1633 if entry.height != height { return true; }
1635 OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1636 *update_source != **source
1641 self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
1644 event: OnchainEvent::HTLCUpdate {
1645 source: (**source).clone(),
1646 payment_hash: htlc.payment_hash.clone(),
1654 if let Some(ref txid) = self.current_counterparty_commitment_txid {
1655 check_htlc_fails!(txid, "current", 'current_loop);
1657 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
1658 check_htlc_fails!(txid, "previous", 'prev_loop);
1661 let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
1662 for req in htlc_claim_reqs {
1663 claimable_outpoints.push(req);
1667 (claimable_outpoints, (commitment_txid, watch_outputs))
1670 fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<PackageTemplate> {
1671 let mut claimable_outpoints = Vec::new();
1672 if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
1673 if let Some(revocation_points) = self.their_cur_revocation_points {
1674 let revocation_point_option =
1675 // If the counterparty commitment tx is the latest valid state, use their latest
1676 // per-commitment point
1677 if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1678 else if let Some(point) = revocation_points.2.as_ref() {
1679 // If counterparty commitment tx is the state previous to the latest valid state, use
1680 // their previous per-commitment point (non-atomicity of revocation means it's valid for
1681 // them to temporarily have two valid commitment txns from our viewpoint)
1682 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1684 if let Some(revocation_point) = revocation_point_option {
1685 for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
1686 if let Some(transaction_output_index) = htlc.transaction_output_index {
1687 if let Some(transaction) = tx {
1688 if transaction_output_index as usize >= transaction.output.len() ||
1689 transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
1690 return claimable_outpoints; // Corrupted per_commitment_data, fuck this user
1693 let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
1694 if preimage.is_some() || !htlc.offered {
1695 let counterparty_htlc_outp = if htlc.offered { PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(*revocation_point, self.counterparty_tx_cache.counterparty_delayed_payment_base_key, self.counterparty_tx_cache.counterparty_htlc_base_key, preimage.unwrap(), htlc.clone())) } else { PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(*revocation_point, self.counterparty_tx_cache.counterparty_delayed_payment_base_key, self.counterparty_tx_cache.counterparty_htlc_base_key, htlc.clone())) };
1696 let aggregation = if !htlc.offered { false } else { true };
1697 let counterparty_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, counterparty_htlc_outp, htlc.cltv_expiry,aggregation, 0);
1698 claimable_outpoints.push(counterparty_package);
1708 /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
1709 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 {
1710 let htlc_txid = tx.txid();
1711 if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
1712 return (Vec::new(), None)
1715 macro_rules! ignore_error {
1716 ( $thing : expr ) => {
1719 Err(_) => return (Vec::new(), None)
1724 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
1725 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1726 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1728 log_error!(logger, "Got broadcast of revoked counterparty HTLC transaction, spending {}:{}", htlc_txid, 0);
1729 let revk_outp = RevokedOutput::build(per_commitment_point, self.counterparty_tx_cache.counterparty_delayed_payment_base_key, self.counterparty_tx_cache.counterparty_htlc_base_key, per_commitment_key, tx.output[0].value, self.counterparty_tx_cache.on_counterparty_tx_csv);
1730 let justice_package = PackageTemplate::build_package(htlc_txid, 0, PackageSolvingData::RevokedOutput(revk_outp), height + self.counterparty_tx_cache.on_counterparty_tx_csv as u32, true, height);
1731 let claimable_outpoints = vec!(justice_package);
1732 let outputs = vec![(0, tx.output[0].clone())];
1733 (claimable_outpoints, Some((htlc_txid, outputs)))
1736 // Returns (1) `PackageTemplate`s that can be given to the OnChainTxHandler, so that the handler can
1737 // broadcast transactions claiming holder HTLC commitment outputs and (2) a holder revokable
1738 // script so we can detect whether a holder transaction has been seen on-chain.
1739 fn get_broadcasted_holder_claims(&self, holder_tx: &HolderSignedTx, conf_height: u32) -> (Vec<PackageTemplate>, Option<(Script, PublicKey, PublicKey)>) {
1740 let mut claim_requests = Vec::with_capacity(holder_tx.htlc_outputs.len());
1742 let redeemscript = chan_utils::get_revokeable_redeemscript(&holder_tx.revocation_key, self.on_holder_tx_csv, &holder_tx.delayed_payment_key);
1743 let broadcasted_holder_revokable_script = Some((redeemscript.to_v0_p2wsh(), holder_tx.per_commitment_point.clone(), holder_tx.revocation_key.clone()));
1745 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1746 if let Some(transaction_output_index) = htlc.transaction_output_index {
1747 let htlc_output = if htlc.offered {
1748 HolderHTLCOutput::build_offered(htlc.amount_msat, htlc.cltv_expiry)
1750 let payment_preimage = if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1753 // We can't build an HTLC-Success transaction without the preimage
1756 HolderHTLCOutput::build_accepted(payment_preimage, htlc.amount_msat)
1758 let htlc_package = PackageTemplate::build_package(holder_tx.txid, transaction_output_index, PackageSolvingData::HolderHTLCOutput(htlc_output), htlc.cltv_expiry, false, conf_height);
1759 claim_requests.push(htlc_package);
1763 (claim_requests, broadcasted_holder_revokable_script)
1766 // Returns holder HTLC outputs to watch and react to in case of spending.
1767 fn get_broadcasted_holder_watch_outputs(&self, holder_tx: &HolderSignedTx, commitment_tx: &Transaction) -> Vec<(u32, TxOut)> {
1768 let mut watch_outputs = Vec::with_capacity(holder_tx.htlc_outputs.len());
1769 for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
1770 if let Some(transaction_output_index) = htlc.transaction_output_index {
1771 watch_outputs.push((transaction_output_index, commitment_tx.output[transaction_output_index as usize].clone()));
1777 /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1778 /// revoked using data in holder_claimable_outpoints.
1779 /// Should not be used if check_spend_revoked_transaction succeeds.
1780 fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<PackageTemplate>, TransactionOutputs) where L::Target: Logger {
1781 let commitment_txid = tx.txid();
1782 let mut claim_requests = Vec::new();
1783 let mut watch_outputs = Vec::new();
1785 macro_rules! wait_threshold_conf {
1786 ($source: expr, $commitment_tx: expr, $payment_hash: expr) => {
1787 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
1788 if entry.height != height { return true; }
1790 OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
1791 *update_source != $source
1796 let entry = OnchainEventEntry {
1797 txid: commitment_txid,
1799 event: OnchainEvent::HTLCUpdate { source: $source, payment_hash: $payment_hash },
1801 log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, entry.confirmation_threshold());
1802 self.onchain_events_awaiting_threshold_conf.push(entry);
1806 macro_rules! append_onchain_update {
1807 ($updates: expr, $to_watch: expr) => {
1808 claim_requests = $updates.0;
1809 self.broadcasted_holder_revokable_script = $updates.1;
1810 watch_outputs.append(&mut $to_watch);
1814 // HTLCs set may differ between last and previous holder commitment txn, in case of one them hitting chain, ensure we cancel all HTLCs backward
1815 let mut is_holder_tx = false;
1817 if self.current_holder_commitment_tx.txid == commitment_txid {
1818 is_holder_tx = true;
1819 log_info!(logger, "Got broadcast of latest holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
1820 let res = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, height);
1821 let mut to_watch = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, tx);
1822 append_onchain_update!(res, to_watch);
1823 } else if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1824 if holder_tx.txid == commitment_txid {
1825 is_holder_tx = true;
1826 log_info!(logger, "Got broadcast of previous holder commitment tx {}, searching for available HTLCs to claim", commitment_txid);
1827 let res = self.get_broadcasted_holder_claims(holder_tx, height);
1828 let mut to_watch = self.get_broadcasted_holder_watch_outputs(holder_tx, tx);
1829 append_onchain_update!(res, to_watch);
1833 macro_rules! fail_dust_htlcs_after_threshold_conf {
1834 ($holder_tx: expr) => {
1835 for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
1836 if htlc.transaction_output_index.is_none() {
1837 if let &Some(ref source) = source {
1838 wait_threshold_conf!(source.clone(), "lastest", htlc.payment_hash.clone());
1846 fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
1847 if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
1848 fail_dust_htlcs_after_threshold_conf!(holder_tx);
1852 (claim_requests, (commitment_txid, watch_outputs))
1855 pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1856 log_debug!(logger, "Getting signed latest holder commitment transaction!");
1857 self.holder_tx_signed = true;
1858 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
1859 let txid = commitment_tx.txid();
1860 let mut holder_transactions = vec![commitment_tx];
1861 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1862 if let Some(vout) = htlc.0.transaction_output_index {
1863 let preimage = if !htlc.0.offered {
1864 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1865 // We can't build an HTLC-Success transaction without the preimage
1868 } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
1869 // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
1870 // current locktime requirements on-chain. We will broadcast them in
1871 // `block_confirmed` when `should_broadcast_holder_commitment_txn` returns true.
1872 // Note that we add + 1 as transactions are broadcastable when they can be
1873 // confirmed in the next block.
1876 if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
1877 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1878 holder_transactions.push(htlc_tx);
1882 // 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.
1883 // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
1887 #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1888 /// Note that this includes possibly-locktimed-in-the-future transactions!
1889 fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
1890 log_debug!(logger, "Getting signed copy of latest holder commitment transaction!");
1891 let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
1892 let txid = commitment_tx.txid();
1893 let mut holder_transactions = vec![commitment_tx];
1894 for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
1895 if let Some(vout) = htlc.0.transaction_output_index {
1896 let preimage = if !htlc.0.offered {
1897 if let Some(preimage) = self.payment_preimages.get(&htlc.0.payment_hash) { Some(preimage.clone()) } else {
1898 // We can't build an HTLC-Success transaction without the preimage
1902 if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
1903 &::bitcoin::OutPoint { txid, vout }, &preimage) {
1904 holder_transactions.push(htlc_tx);
1911 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>
1912 where B::Target: BroadcasterInterface,
1913 F::Target: FeeEstimator,
1916 let block_hash = header.block_hash();
1917 log_trace!(logger, "New best block {} at height {}", block_hash, height);
1918 self.best_block = BestBlock::new(block_hash, height);
1920 self.transactions_confirmed(header, txdata, height, broadcaster, fee_estimator, logger)
1923 fn best_block_updated<B: Deref, F: Deref, L: Deref>(
1925 header: &BlockHeader,
1930 ) -> Vec<TransactionOutputs>
1932 B::Target: BroadcasterInterface,
1933 F::Target: FeeEstimator,
1936 let block_hash = header.block_hash();
1937 log_trace!(logger, "New best block {} at height {}", block_hash, height);
1939 if height > self.best_block.height() {
1940 self.best_block = BestBlock::new(block_hash, height);
1941 self.block_confirmed(height, vec![], vec![], vec![], &broadcaster, &fee_estimator, &logger)
1942 } else if block_hash != self.best_block.block_hash() {
1943 self.best_block = BestBlock::new(block_hash, height);
1944 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
1945 self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
1947 } else { Vec::new() }
1950 fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
1952 header: &BlockHeader,
1953 txdata: &TransactionData,
1958 ) -> Vec<TransactionOutputs>
1960 B::Target: BroadcasterInterface,
1961 F::Target: FeeEstimator,
1964 let txn_matched = self.filter_block(txdata);
1965 for tx in &txn_matched {
1966 let mut output_val = 0;
1967 for out in tx.output.iter() {
1968 if out.value > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1969 output_val += out.value;
1970 if output_val > 21_000_000_0000_0000 { panic!("Value-overflowing transaction provided to block connected"); }
1974 let block_hash = header.block_hash();
1975 log_trace!(logger, "Block {} at height {} connected with {} txn matched", block_hash, height, txn_matched.len());
1977 let mut watch_outputs = Vec::new();
1978 let mut claimable_outpoints = Vec::new();
1979 for tx in &txn_matched {
1980 if tx.input.len() == 1 {
1981 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1982 // commitment transactions and HTLC transactions will all only ever have one input,
1983 // which is an easy way to filter out any potential non-matching txn for lazy
1985 let prevout = &tx.input[0].previous_output;
1986 if prevout.txid == self.funding_info.0.txid && prevout.vout == self.funding_info.0.index as u32 {
1987 if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
1988 let (mut new_outpoints, new_outputs) = self.check_spend_counterparty_transaction(&tx, height, &logger);
1989 if !new_outputs.1.is_empty() {
1990 watch_outputs.push(new_outputs);
1992 if new_outpoints.is_empty() {
1993 let (mut new_outpoints, new_outputs) = self.check_spend_holder_transaction(&tx, height, &logger);
1994 if !new_outputs.1.is_empty() {
1995 watch_outputs.push(new_outputs);
1997 claimable_outpoints.append(&mut new_outpoints);
1999 claimable_outpoints.append(&mut new_outpoints);
2002 if let Some(&commitment_number) = self.counterparty_commitment_txn_on_chain.get(&prevout.txid) {
2003 let (mut new_outpoints, new_outputs_option) = self.check_spend_counterparty_htlc(&tx, commitment_number, height, &logger);
2004 claimable_outpoints.append(&mut new_outpoints);
2005 if let Some(new_outputs) = new_outputs_option {
2006 watch_outputs.push(new_outputs);
2011 // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
2012 // can also be resolved in a few other ways which can have more than one output. Thus,
2013 // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
2014 self.is_resolving_htlc_output(&tx, height, &logger);
2016 self.is_paying_spendable_output(&tx, height, &logger);
2019 if height > self.best_block.height() {
2020 self.best_block = BestBlock::new(block_hash, height);
2023 self.block_confirmed(height, txn_matched, watch_outputs, claimable_outpoints, &broadcaster, &fee_estimator, &logger)
2026 /// Update state for new block(s)/transaction(s) confirmed. Note that the caller must update
2027 /// `self.best_block` before calling if a new best blockchain tip is available. More
2028 /// concretely, `self.best_block` must never be at a lower height than `conf_height`, avoiding
2029 /// complexity especially in `OnchainTx::update_claims_view`.
2031 /// `conf_height` should be set to the height at which any new transaction(s)/block(s) were
2032 /// confirmed at, even if it is not the current best height.
2033 fn block_confirmed<B: Deref, F: Deref, L: Deref>(
2036 txn_matched: Vec<&Transaction>,
2037 mut watch_outputs: Vec<TransactionOutputs>,
2038 mut claimable_outpoints: Vec<PackageTemplate>,
2042 ) -> Vec<TransactionOutputs>
2044 B::Target: BroadcasterInterface,
2045 F::Target: FeeEstimator,
2048 debug_assert!(self.best_block.height() >= conf_height);
2050 let should_broadcast = self.should_broadcast_holder_commitment_txn(logger);
2051 if should_broadcast {
2052 let funding_outp = HolderFundingOutput::build(self.funding_redeemscript.clone());
2053 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());
2054 claimable_outpoints.push(commitment_package);
2055 self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
2056 let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
2057 self.holder_tx_signed = true;
2058 // Because we're broadcasting a commitment transaction, we should construct the package
2059 // assuming it gets confirmed in the next block. Sadly, we have code which considers
2060 // "not yet confirmed" things as discardable, so we cannot do that here.
2061 let (mut new_outpoints, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx, self.best_block.height());
2062 let new_outputs = self.get_broadcasted_holder_watch_outputs(&self.current_holder_commitment_tx, &commitment_tx);
2063 if !new_outputs.is_empty() {
2064 watch_outputs.push((self.current_holder_commitment_tx.txid.clone(), new_outputs));
2066 claimable_outpoints.append(&mut new_outpoints);
2069 // Find which on-chain events have reached their confirmation threshold.
2070 let onchain_events_awaiting_threshold_conf =
2071 self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
2072 let mut onchain_events_reaching_threshold_conf = Vec::new();
2073 for entry in onchain_events_awaiting_threshold_conf {
2074 if entry.has_reached_confirmation_threshold(&self.best_block) {
2075 onchain_events_reaching_threshold_conf.push(entry);
2077 self.onchain_events_awaiting_threshold_conf.push(entry);
2081 // Used to check for duplicate HTLC resolutions.
2082 #[cfg(debug_assertions)]
2083 let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
2085 .filter_map(|entry| match &entry.event {
2086 OnchainEvent::HTLCUpdate { source, .. } => Some(source),
2087 OnchainEvent::MaturingOutput { .. } => None,
2090 #[cfg(debug_assertions)]
2091 let mut matured_htlcs = Vec::new();
2093 // Produce actionable events from on-chain events having reached their threshold.
2094 for entry in onchain_events_reaching_threshold_conf.drain(..) {
2096 OnchainEvent::HTLCUpdate { ref source, payment_hash } => {
2097 // Check for duplicate HTLC resolutions.
2098 #[cfg(debug_assertions)]
2101 unmatured_htlcs.iter().find(|&htlc| htlc == &source).is_none(),
2102 "An unmature HTLC transaction conflicts with a maturing one; failed to \
2103 call either transaction_unconfirmed for the conflicting transaction \
2104 or block_disconnected for a block containing it.");
2106 matured_htlcs.iter().find(|&htlc| htlc == source).is_none(),
2107 "A matured HTLC transaction conflicts with a maturing one; failed to \
2108 call either transaction_unconfirmed for the conflicting transaction \
2109 or block_disconnected for a block containing it.");
2110 matured_htlcs.push(source.clone());
2113 log_debug!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!(payment_hash.0));
2114 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2115 payment_hash: payment_hash,
2116 payment_preimage: None,
2117 source: source.clone(),
2120 OnchainEvent::MaturingOutput { descriptor } => {
2121 log_debug!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
2122 self.pending_events.push(Event::SpendableOutputs {
2123 outputs: vec![descriptor]
2129 self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, conf_height, self.best_block.height(), broadcaster, fee_estimator, logger);
2131 // Determine new outputs to watch by comparing against previously known outputs to watch,
2132 // updating the latter in the process.
2133 watch_outputs.retain(|&(ref txid, ref txouts)| {
2134 let idx_and_scripts = txouts.iter().map(|o| (o.0, o.1.script_pubkey.clone())).collect();
2135 self.outputs_to_watch.insert(txid.clone(), idx_and_scripts).is_none()
2139 // If we see a transaction for which we registered outputs previously,
2140 // make sure the registered scriptpubkey at the expected index match
2141 // the actual transaction output one. We failed this case before #653.
2142 for tx in &txn_matched {
2143 if let Some(outputs) = self.get_outputs_to_watch().get(&tx.txid()) {
2144 for idx_and_script in outputs.iter() {
2145 assert!((idx_and_script.0 as usize) < tx.output.len());
2146 assert_eq!(tx.output[idx_and_script.0 as usize].script_pubkey, idx_and_script.1);
2154 pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
2155 where B::Target: BroadcasterInterface,
2156 F::Target: FeeEstimator,
2159 log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
2162 //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
2163 //- maturing spendable output has transaction paying us has been disconnected
2164 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
2166 self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
2168 self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
2171 fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
2178 B::Target: BroadcasterInterface,
2179 F::Target: FeeEstimator,
2182 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.txid != *txid);
2183 self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
2186 /// Filters a block's `txdata` for transactions spending watched outputs or for any child
2187 /// transactions thereof.
2188 fn filter_block<'a>(&self, txdata: &TransactionData<'a>) -> Vec<&'a Transaction> {
2189 let mut matched_txn = HashSet::new();
2190 txdata.iter().filter(|&&(_, tx)| {
2191 let mut matches = self.spends_watched_output(tx);
2192 for input in tx.input.iter() {
2193 if matches { break; }
2194 if matched_txn.contains(&input.previous_output.txid) {
2199 matched_txn.insert(tx.txid());
2202 }).map(|(_, tx)| *tx).collect()
2205 /// Checks if a given transaction spends any watched outputs.
2206 fn spends_watched_output(&self, tx: &Transaction) -> bool {
2207 for input in tx.input.iter() {
2208 if let Some(outputs) = self.get_outputs_to_watch().get(&input.previous_output.txid) {
2209 for (idx, _script_pubkey) in outputs.iter() {
2210 if *idx == input.previous_output.vout {
2213 // If the expected script is a known type, check that the witness
2214 // appears to be spending the correct type (ie that the match would
2215 // actually succeed in BIP 158/159-style filters).
2216 if _script_pubkey.is_v0_p2wsh() {
2217 assert_eq!(&bitcoin::Address::p2wsh(&Script::from(input.witness.last().unwrap().clone()), bitcoin::Network::Bitcoin).script_pubkey(), _script_pubkey);
2218 } else if _script_pubkey.is_v0_p2wpkh() {
2219 assert_eq!(&bitcoin::Address::p2wpkh(&bitcoin::PublicKey::from_slice(&input.witness.last().unwrap()).unwrap(), bitcoin::Network::Bitcoin).unwrap().script_pubkey(), _script_pubkey);
2220 } else { panic!(); }
2231 fn should_broadcast_holder_commitment_txn<L: Deref>(&self, logger: &L) -> bool where L::Target: Logger {
2232 // We need to consider all HTLCs which are:
2233 // * in any unrevoked counterparty commitment transaction, as they could broadcast said
2234 // transactions and we'd end up in a race, or
2235 // * are in our latest holder commitment transaction, as this is the thing we will
2236 // broadcast if we go on-chain.
2237 // Note that we consider HTLCs which were below dust threshold here - while they don't
2238 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
2239 // to the source, and if we don't fail the channel we will have to ensure that the next
2240 // updates that peer sends us are update_fails, failing the channel if not. It's probably
2241 // easier to just fail the channel as this case should be rare enough anyway.
2242 let height = self.best_block.height();
2243 macro_rules! scan_commitment {
2244 ($htlcs: expr, $holder_tx: expr) => {
2245 for ref htlc in $htlcs {
2246 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
2247 // chain with enough room to claim the HTLC without our counterparty being able to
2248 // time out the HTLC first.
2249 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
2250 // concern is being able to claim the corresponding inbound HTLC (on another
2251 // channel) before it expires. In fact, we don't even really care if our
2252 // counterparty here claims such an outbound HTLC after it expired as long as we
2253 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
2254 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
2255 // we give ourselves a few blocks of headroom after expiration before going
2256 // on-chain for an expired HTLC.
2257 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
2258 // from us until we've reached the point where we go on-chain with the
2259 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
2260 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
2261 // aka outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS == height - CLTV_CLAIM_BUFFER
2262 // inbound_cltv == height + CLTV_CLAIM_BUFFER
2263 // outbound_cltv + LATENCY_GRACE_PERIOD_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
2264 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
2265 // CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
2266 // LATENCY_GRACE_PERIOD_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
2267 // The final, above, condition is checked for statically in channelmanager
2268 // with CHECK_CLTV_EXPIRY_SANITY_2.
2269 let htlc_outbound = $holder_tx == htlc.offered;
2270 if ( htlc_outbound && htlc.cltv_expiry + LATENCY_GRACE_PERIOD_BLOCKS <= height) ||
2271 (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
2272 log_info!(logger, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
2279 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
2281 if let Some(ref txid) = self.current_counterparty_commitment_txid {
2282 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2283 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2286 if let Some(ref txid) = self.prev_counterparty_commitment_txid {
2287 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(txid) {
2288 scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
2295 /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a holder
2296 /// or counterparty commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
2297 fn is_resolving_htlc_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2298 'outer_loop: for input in &tx.input {
2299 let mut payment_data = None;
2300 let revocation_sig_claim = (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC) && input.witness[1].len() == 33)
2301 || (input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::AcceptedHTLC) && input.witness[1].len() == 33);
2302 let accepted_preimage_claim = input.witness.len() == 5 && HTLCType::scriptlen_to_htlctype(input.witness[4].len()) == Some(HTLCType::AcceptedHTLC);
2303 let offered_preimage_claim = input.witness.len() == 3 && HTLCType::scriptlen_to_htlctype(input.witness[2].len()) == Some(HTLCType::OfferedHTLC);
2305 macro_rules! log_claim {
2306 ($tx_info: expr, $holder_tx: expr, $htlc: expr, $source_avail: expr) => {
2307 // We found the output in question, but aren't failing it backwards
2308 // as we have no corresponding source and no valid counterparty commitment txid
2309 // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
2310 // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
2311 let outbound_htlc = $holder_tx == $htlc.offered;
2312 if ($holder_tx && revocation_sig_claim) ||
2313 (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
2314 log_error!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
2315 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2316 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2317 if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
2319 log_info!(logger, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
2320 $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
2321 if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
2322 if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
2327 macro_rules! check_htlc_valid_counterparty {
2328 ($counterparty_txid: expr, $htlc_output: expr) => {
2329 if let Some(txid) = $counterparty_txid {
2330 for &(ref pending_htlc, ref pending_source) in self.counterparty_claimable_outpoints.get(&txid).unwrap() {
2331 if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
2332 if let &Some(ref source) = pending_source {
2333 log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
2334 payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
2343 macro_rules! scan_commitment {
2344 ($htlcs: expr, $tx_info: expr, $holder_tx: expr) => {
2345 for (ref htlc_output, source_option) in $htlcs {
2346 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
2347 if let Some(ref source) = source_option {
2348 log_claim!($tx_info, $holder_tx, htlc_output, true);
2349 // We have a resolution of an HTLC either from one of our latest
2350 // holder commitment transactions or an unrevoked counterparty commitment
2351 // transaction. This implies we either learned a preimage, the HTLC
2352 // has timed out, or we screwed up. In any case, we should now
2353 // resolve the source HTLC with the original sender.
2354 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
2355 } else if !$holder_tx {
2356 check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
2357 if payment_data.is_none() {
2358 check_htlc_valid_counterparty!(self.prev_counterparty_commitment_txid, htlc_output);
2361 if payment_data.is_none() {
2362 log_claim!($tx_info, $holder_tx, htlc_output, false);
2363 continue 'outer_loop;
2370 if input.previous_output.txid == self.current_holder_commitment_tx.txid {
2371 scan_commitment!(self.current_holder_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2372 "our latest holder commitment tx", true);
2374 if let Some(ref prev_holder_signed_commitment_tx) = self.prev_holder_signed_commitment_tx {
2375 if input.previous_output.txid == prev_holder_signed_commitment_tx.txid {
2376 scan_commitment!(prev_holder_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2377 "our previous holder commitment tx", true);
2380 if let Some(ref htlc_outputs) = self.counterparty_claimable_outpoints.get(&input.previous_output.txid) {
2381 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2382 "counterparty commitment tx", false);
2385 // Check that scan_commitment, above, decided there is some source worth relaying an
2386 // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2387 if let Some((source, payment_hash)) = payment_data {
2388 let mut payment_preimage = PaymentPreimage([0; 32]);
2389 if accepted_preimage_claim {
2390 if !self.pending_monitor_events.iter().any(
2391 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update { upd.source == source } else { false }) {
2392 payment_preimage.0.copy_from_slice(&input.witness[3]);
2393 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2395 payment_preimage: Some(payment_preimage),
2399 } else if offered_preimage_claim {
2400 if !self.pending_monitor_events.iter().any(
2401 |update| if let &MonitorEvent::HTLCEvent(ref upd) = update {
2402 upd.source == source
2404 payment_preimage.0.copy_from_slice(&input.witness[1]);
2405 self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
2407 payment_preimage: Some(payment_preimage),
2412 self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
2413 if entry.height != height { return true; }
2415 OnchainEvent::HTLCUpdate { source: ref htlc_source, .. } => {
2416 *htlc_source != source
2421 let entry = OnchainEventEntry {
2424 event: OnchainEvent::HTLCUpdate { source: source, payment_hash: payment_hash },
2426 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());
2427 self.onchain_events_awaiting_threshold_conf.push(entry);
2433 /// Check if any transaction broadcasted is paying fund back to some address we can assume to own
2434 fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
2435 let mut spendable_output = None;
2436 for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
2437 if i > ::core::u16::MAX as usize {
2438 // While it is possible that an output exists on chain which is greater than the
2439 // 2^16th output in a given transaction, this is only possible if the output is not
2440 // in a lightning transaction and was instead placed there by some third party who
2441 // wishes to give us money for no reason.
2442 // Namely, any lightning transactions which we pre-sign will never have anywhere
2443 // near 2^16 outputs both because such transactions must have ~2^16 outputs who's
2444 // scripts are not longer than one byte in length and because they are inherently
2445 // non-standard due to their size.
2446 // Thus, it is completely safe to ignore such outputs, and while it may result in
2447 // us ignoring non-lightning fund to us, that is only possible if someone fills
2448 // nearly a full block with garbage just to hit this case.
2451 if outp.script_pubkey == self.destination_script {
2452 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2453 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2454 output: outp.clone(),
2457 } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
2458 if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
2459 spendable_output = Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
2460 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2461 per_commitment_point: broadcasted_holder_revokable_script.1,
2462 to_self_delay: self.on_holder_tx_csv,
2463 output: outp.clone(),
2464 revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
2465 channel_keys_id: self.channel_keys_id,
2466 channel_value_satoshis: self.channel_value_satoshis,
2470 } else if self.counterparty_payment_script == outp.script_pubkey {
2471 spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
2472 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2473 output: outp.clone(),
2474 channel_keys_id: self.channel_keys_id,
2475 channel_value_satoshis: self.channel_value_satoshis,
2478 } else if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
2479 spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
2480 outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
2481 output: outp.clone(),
2485 if let Some(spendable_output) = spendable_output {
2486 let entry = OnchainEventEntry {
2489 event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
2491 log_info!(logger, "Received spendable output {}, spendable at height {}", log_spendable!(spendable_output), entry.confirmation_threshold());
2492 self.onchain_events_awaiting_threshold_conf.push(entry);
2497 /// `Persist` defines behavior for persisting channel monitors: this could mean
2498 /// writing once to disk, and/or uploading to one or more backup services.
2500 /// Note that for every new monitor, you **must** persist the new `ChannelMonitor`
2501 /// to disk/backups. And, on every update, you **must** persist either the
2502 /// `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
2503 /// of situations such as revoking a transaction, then crashing before this
2504 /// revocation can be persisted, then unintentionally broadcasting a revoked
2505 /// transaction and losing money. This is a risk because previous channel states
2506 /// are toxic, so it's important that whatever channel state is persisted is
2507 /// kept up-to-date.
2508 pub trait Persist<ChannelSigner: Sign> {
2509 /// Persist a new channel's data. The data can be stored any way you want, but
2510 /// the identifier provided by Rust-Lightning is the channel's outpoint (and
2511 /// it is up to you to maintain a correct mapping between the outpoint and the
2512 /// stored channel data). Note that you **must** persist every new monitor to
2513 /// disk. See the `Persist` trait documentation for more details.
2515 /// See [`ChannelMonitor::write`] for writing out a `ChannelMonitor`,
2516 /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2517 fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2519 /// Update one channel's data. The provided `ChannelMonitor` has already
2520 /// applied the given update.
2522 /// Note that on every update, you **must** persist either the
2523 /// `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
2524 /// the `Persist` trait documentation for more details.
2526 /// If an implementer chooses to persist the updates only, they need to make
2527 /// sure that all the updates are applied to the `ChannelMonitors` *before*
2528 /// the set of channel monitors is given to the `ChannelManager`
2529 /// deserialization routine. See [`ChannelMonitor::update_monitor`] for
2530 /// applying a monitor update to a monitor. If full `ChannelMonitors` are
2531 /// persisted, then there is no need to persist individual updates.
2533 /// Note that there could be a performance tradeoff between persisting complete
2534 /// channel monitors on every update vs. persisting only updates and applying
2535 /// them in batches. The size of each monitor grows `O(number of state updates)`
2536 /// whereas updates are small and `O(1)`.
2538 /// See [`ChannelMonitor::write`] for writing out a `ChannelMonitor`,
2539 /// [`ChannelMonitorUpdate::write`] for writing out an update, and
2540 /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
2541 fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
2544 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
2546 T::Target: BroadcasterInterface,
2547 F::Target: FeeEstimator,
2550 fn block_connected(&self, block: &Block, height: u32) {
2551 let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
2552 self.0.block_connected(&block.header, &txdata, height, &*self.1, &*self.2, &*self.3);
2555 fn block_disconnected(&self, header: &BlockHeader, height: u32) {
2556 self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
2560 impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
2562 T::Target: BroadcasterInterface,
2563 F::Target: FeeEstimator,
2566 fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
2567 self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
2570 fn transaction_unconfirmed(&self, txid: &Txid) {
2571 self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
2574 fn best_block_updated(&self, header: &BlockHeader, height: u32) {
2575 self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
2578 fn get_relevant_txids(&self) -> Vec<Txid> {
2579 self.0.get_relevant_txids()
2583 const MAX_ALLOC_SIZE: usize = 64*1024;
2585 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
2586 for (BlockHash, ChannelMonitor<Signer>) {
2587 fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
2588 macro_rules! unwrap_obj {
2592 Err(_) => return Err(DecodeError::InvalidValue),
2597 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
2599 let latest_update_id: u64 = Readable::read(reader)?;
2600 let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
2602 let destination_script = Readable::read(reader)?;
2603 let broadcasted_holder_revokable_script = match <u8 as Readable>::read(reader)? {
2605 let revokable_address = Readable::read(reader)?;
2606 let per_commitment_point = Readable::read(reader)?;
2607 let revokable_script = Readable::read(reader)?;
2608 Some((revokable_address, per_commitment_point, revokable_script))
2611 _ => return Err(DecodeError::InvalidValue),
2613 let counterparty_payment_script = Readable::read(reader)?;
2614 let mut shutdown_script = {
2615 let script = <Script as Readable>::read(reader)?;
2616 if script.is_empty() { None } else { Some(script) }
2619 let channel_keys_id = Readable::read(reader)?;
2620 let holder_revocation_basepoint = Readable::read(reader)?;
2621 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2622 // barely-init'd ChannelMonitors that we can't do anything with.
2623 let outpoint = OutPoint {
2624 txid: Readable::read(reader)?,
2625 index: Readable::read(reader)?,
2627 let funding_info = (outpoint, Readable::read(reader)?);
2628 let current_counterparty_commitment_txid = Readable::read(reader)?;
2629 let prev_counterparty_commitment_txid = Readable::read(reader)?;
2631 let counterparty_tx_cache = Readable::read(reader)?;
2632 let funding_redeemscript = Readable::read(reader)?;
2633 let channel_value_satoshis = Readable::read(reader)?;
2635 let their_cur_revocation_points = {
2636 let first_idx = <U48 as Readable>::read(reader)?.0;
2640 let first_point = Readable::read(reader)?;
2641 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2642 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2643 Some((first_idx, first_point, None))
2645 Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2650 let on_holder_tx_csv: u16 = Readable::read(reader)?;
2652 let commitment_secrets = Readable::read(reader)?;
2654 macro_rules! read_htlc_in_commitment {
2657 let offered: bool = Readable::read(reader)?;
2658 let amount_msat: u64 = Readable::read(reader)?;
2659 let cltv_expiry: u32 = Readable::read(reader)?;
2660 let payment_hash: PaymentHash = Readable::read(reader)?;
2661 let transaction_output_index: Option<u32> = Readable::read(reader)?;
2663 HTLCOutputInCommitment {
2664 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2670 let counterparty_claimable_outpoints_len: u64 = Readable::read(reader)?;
2671 let mut counterparty_claimable_outpoints = HashMap::with_capacity(cmp::min(counterparty_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2672 for _ in 0..counterparty_claimable_outpoints_len {
2673 let txid: Txid = Readable::read(reader)?;
2674 let htlcs_count: u64 = Readable::read(reader)?;
2675 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2676 for _ in 0..htlcs_count {
2677 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2679 if let Some(_) = counterparty_claimable_outpoints.insert(txid, htlcs) {
2680 return Err(DecodeError::InvalidValue);
2684 let counterparty_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2685 let mut counterparty_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(counterparty_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2686 for _ in 0..counterparty_commitment_txn_on_chain_len {
2687 let txid: Txid = Readable::read(reader)?;
2688 let commitment_number = <U48 as Readable>::read(reader)?.0;
2689 if let Some(_) = counterparty_commitment_txn_on_chain.insert(txid, commitment_number) {
2690 return Err(DecodeError::InvalidValue);
2694 let counterparty_hash_commitment_number_len: u64 = Readable::read(reader)?;
2695 let mut counterparty_hash_commitment_number = HashMap::with_capacity(cmp::min(counterparty_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2696 for _ in 0..counterparty_hash_commitment_number_len {
2697 let payment_hash: PaymentHash = Readable::read(reader)?;
2698 let commitment_number = <U48 as Readable>::read(reader)?.0;
2699 if let Some(_) = counterparty_hash_commitment_number.insert(payment_hash, commitment_number) {
2700 return Err(DecodeError::InvalidValue);
2704 let prev_holder_signed_commitment_tx = match <u8 as Readable>::read(reader)? {
2707 Some(Readable::read(reader)?)
2709 _ => return Err(DecodeError::InvalidValue),
2711 let current_holder_commitment_tx = Readable::read(reader)?;
2713 let current_counterparty_commitment_number = <U48 as Readable>::read(reader)?.0;
2714 let current_holder_commitment_number = <U48 as Readable>::read(reader)?.0;
2716 let payment_preimages_len: u64 = Readable::read(reader)?;
2717 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2718 for _ in 0..payment_preimages_len {
2719 let preimage: PaymentPreimage = Readable::read(reader)?;
2720 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2721 if let Some(_) = payment_preimages.insert(hash, preimage) {
2722 return Err(DecodeError::InvalidValue);
2726 let pending_monitor_events_len: u64 = Readable::read(reader)?;
2727 let mut pending_monitor_events = Vec::with_capacity(cmp::min(pending_monitor_events_len as usize, MAX_ALLOC_SIZE / (32 + 8*3)));
2728 for _ in 0..pending_monitor_events_len {
2729 let ev = match <u8 as Readable>::read(reader)? {
2730 0 => MonitorEvent::HTLCEvent(Readable::read(reader)?),
2731 1 => MonitorEvent::CommitmentTxBroadcasted(funding_info.0),
2732 _ => return Err(DecodeError::InvalidValue)
2734 pending_monitor_events.push(ev);
2737 let pending_events_len: u64 = Readable::read(reader)?;
2738 let mut pending_events = Vec::with_capacity(cmp::min(pending_events_len as usize, MAX_ALLOC_SIZE / mem::size_of::<Event>()));
2739 for _ in 0..pending_events_len {
2740 if let Some(event) = MaybeReadable::read(reader)? {
2741 pending_events.push(event);
2745 let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
2747 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
2748 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
2749 for _ in 0..waiting_threshold_conf_len {
2750 onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?);
2753 let outputs_to_watch_len: u64 = Readable::read(reader)?;
2754 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>>())));
2755 for _ in 0..outputs_to_watch_len {
2756 let txid = Readable::read(reader)?;
2757 let outputs_len: u64 = Readable::read(reader)?;
2758 let mut outputs = Vec::with_capacity(cmp::min(outputs_len as usize, MAX_ALLOC_SIZE / (mem::size_of::<u32>() + mem::size_of::<Script>())));
2759 for _ in 0..outputs_len {
2760 outputs.push((Readable::read(reader)?, Readable::read(reader)?));
2762 if let Some(_) = outputs_to_watch.insert(txid, outputs) {
2763 return Err(DecodeError::InvalidValue);
2766 let onchain_tx_handler = ReadableArgs::read(reader, keys_manager)?;
2768 let lockdown_from_offchain = Readable::read(reader)?;
2769 let holder_tx_signed = Readable::read(reader)?;
2771 read_tlv_fields!(reader, {
2772 (1, shutdown_script, option),
2775 let mut secp_ctx = Secp256k1::new();
2776 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
2778 Ok((best_block.block_hash(), ChannelMonitor {
2779 inner: Mutex::new(ChannelMonitorImpl {
2781 commitment_transaction_number_obscure_factor,
2784 broadcasted_holder_revokable_script,
2785 counterparty_payment_script,
2789 holder_revocation_basepoint,
2791 current_counterparty_commitment_txid,
2792 prev_counterparty_commitment_txid,
2794 counterparty_tx_cache,
2795 funding_redeemscript,
2796 channel_value_satoshis,
2797 their_cur_revocation_points,
2802 counterparty_claimable_outpoints,
2803 counterparty_commitment_txn_on_chain,
2804 counterparty_hash_commitment_number,
2806 prev_holder_signed_commitment_tx,
2807 current_holder_commitment_tx,
2808 current_counterparty_commitment_number,
2809 current_holder_commitment_number,
2812 pending_monitor_events,
2815 onchain_events_awaiting_threshold_conf,
2820 lockdown_from_offchain,
2833 use bitcoin::blockdata::script::{Script, Builder};
2834 use bitcoin::blockdata::opcodes;
2835 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2836 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2837 use bitcoin::util::bip143;
2838 use bitcoin::hashes::Hash;
2839 use bitcoin::hashes::sha256::Hash as Sha256;
2840 use bitcoin::hashes::hex::FromHex;
2841 use bitcoin::hash_types::Txid;
2842 use bitcoin::network::constants::Network;
2844 use chain::BestBlock;
2845 use chain::channelmonitor::ChannelMonitor;
2846 use chain::package::{WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC, WEIGHT_REVOKED_OUTPUT};
2847 use chain::transaction::OutPoint;
2848 use ln::{PaymentPreimage, PaymentHash};
2850 use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
2851 use ln::script::ShutdownScript;
2852 use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
2853 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
2854 use bitcoin::secp256k1::Secp256k1;
2855 use sync::{Arc, Mutex};
2856 use chain::keysinterface::InMemorySigner;
2860 fn test_prune_preimages() {
2861 let secp_ctx = Secp256k1::new();
2862 let logger = Arc::new(TestLogger::new());
2863 let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
2864 let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: Mutex::new(253) });
2866 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2867 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2869 let mut preimages = Vec::new();
2872 let preimage = PaymentPreimage([i; 32]);
2873 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2874 preimages.push((preimage, hash));
2878 macro_rules! preimages_slice_to_htlc_outputs {
2879 ($preimages_slice: expr) => {
2881 let mut res = Vec::new();
2882 for (idx, preimage) in $preimages_slice.iter().enumerate() {
2883 res.push((HTLCOutputInCommitment {
2887 payment_hash: preimage.1.clone(),
2888 transaction_output_index: Some(idx as u32),
2895 macro_rules! preimages_to_holder_htlcs {
2896 ($preimages_slice: expr) => {
2898 let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2899 let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2905 macro_rules! test_preimages_exist {
2906 ($preimages_slice: expr, $monitor: expr) => {
2907 for preimage in $preimages_slice {
2908 assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
2913 let keys = InMemorySigner::new(
2915 SecretKey::from_slice(&[41; 32]).unwrap(),
2916 SecretKey::from_slice(&[41; 32]).unwrap(),
2917 SecretKey::from_slice(&[41; 32]).unwrap(),
2918 SecretKey::from_slice(&[41; 32]).unwrap(),
2919 SecretKey::from_slice(&[41; 32]).unwrap(),
2925 let counterparty_pubkeys = ChannelPublicKeys {
2926 funding_pubkey: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[44; 32]).unwrap()),
2927 revocation_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()),
2928 payment_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap()),
2929 delayed_payment_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[47; 32]).unwrap()),
2930 htlc_basepoint: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[48; 32]).unwrap())
2932 let funding_outpoint = OutPoint { txid: Default::default(), index: u16::max_value() };
2933 let channel_parameters = ChannelTransactionParameters {
2934 holder_pubkeys: keys.holder_channel_pubkeys.clone(),
2935 holder_selected_contest_delay: 66,
2936 is_outbound_from_holder: true,
2937 counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
2938 pubkeys: counterparty_pubkeys,
2939 selected_contest_delay: 67,
2941 funding_outpoint: Some(funding_outpoint),
2943 // Prune with one old state and a holder commitment tx holding a few overlaps with the
2945 let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2946 let best_block = BestBlock::from_genesis(Network::Testnet);
2947 let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
2948 Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
2949 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
2950 &channel_parameters,
2951 Script::new(), 46, 0,
2952 HolderCommitmentTransaction::dummy(), best_block);
2954 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
2955 let dummy_txid = dummy_tx.txid();
2956 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
2957 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key, &logger);
2958 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key, &logger);
2959 monitor.provide_latest_counterparty_commitment_tx(dummy_txid, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key, &logger);
2960 for &(ref preimage, ref hash) in preimages.iter() {
2961 monitor.provide_payment_preimage(hash, preimage, &broadcaster, &fee_estimator, &logger);
2964 // Now provide a secret, pruning preimages 10-15
2965 let mut secret = [0; 32];
2966 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2967 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2968 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
2969 test_preimages_exist!(&preimages[0..10], monitor);
2970 test_preimages_exist!(&preimages[15..20], monitor);
2972 // Now provide a further secret, pruning preimages 15-17
2973 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2974 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2975 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
2976 test_preimages_exist!(&preimages[0..10], monitor);
2977 test_preimages_exist!(&preimages[17..20], monitor);
2979 // Now update holder commitment tx info, pruning only element 18 as we still care about the
2980 // previous commitment tx's preimages too
2981 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
2982 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2983 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2984 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
2985 test_preimages_exist!(&preimages[0..10], monitor);
2986 test_preimages_exist!(&preimages[18..20], monitor);
2988 // But if we do it again, we'll prune 5-10
2989 monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
2990 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2991 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2992 assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
2993 test_preimages_exist!(&preimages[0..5], monitor);
2997 fn test_claim_txn_weight_computation() {
2998 // We test Claim txn weight, knowing that we want expected weigth and
2999 // not actual case to avoid sigs and time-lock delays hell variances.
3001 let secp_ctx = Secp256k1::new();
3002 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
3003 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
3004 let mut sum_actual_sigs = 0;
3006 macro_rules! sign_input {
3007 ($sighash_parts: expr, $idx: expr, $amount: expr, $weight: expr, $sum_actual_sigs: expr) => {
3008 let htlc = HTLCOutputInCommitment {
3009 offered: if *$weight == WEIGHT_REVOKED_OFFERED_HTLC || *$weight == WEIGHT_OFFERED_HTLC { true } else { false },
3011 cltv_expiry: 2 << 16,
3012 payment_hash: PaymentHash([1; 32]),
3013 transaction_output_index: Some($idx as u32),
3015 let redeem_script = if *$weight == WEIGHT_REVOKED_OUTPUT { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
3016 let sighash = hash_to_message!(&$sighash_parts.signature_hash($idx, &redeem_script, $amount, SigHashType::All)[..]);
3017 let sig = secp_ctx.sign(&sighash, &privkey);
3018 $sighash_parts.access_witness($idx).push(sig.serialize_der().to_vec());
3019 $sighash_parts.access_witness($idx)[0].push(SigHashType::All as u8);
3020 sum_actual_sigs += $sighash_parts.access_witness($idx)[0].len();
3021 if *$weight == WEIGHT_REVOKED_OUTPUT {
3022 $sighash_parts.access_witness($idx).push(vec!(1));
3023 } else if *$weight == WEIGHT_REVOKED_OFFERED_HTLC || *$weight == WEIGHT_REVOKED_RECEIVED_HTLC {
3024 $sighash_parts.access_witness($idx).push(pubkey.clone().serialize().to_vec());
3025 } else if *$weight == WEIGHT_RECEIVED_HTLC {
3026 $sighash_parts.access_witness($idx).push(vec![0]);
3028 $sighash_parts.access_witness($idx).push(PaymentPreimage([1; 32]).0.to_vec());
3030 $sighash_parts.access_witness($idx).push(redeem_script.into_bytes());
3031 println!("witness[0] {}", $sighash_parts.access_witness($idx)[0].len());
3032 println!("witness[1] {}", $sighash_parts.access_witness($idx)[1].len());
3033 println!("witness[2] {}", $sighash_parts.access_witness($idx)[2].len());
3037 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
3038 let txid = Txid::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
3040 // Justice tx with 1 to_holder, 2 revoked offered HTLCs, 1 revoked received HTLCs
3041 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
3043 claim_tx.input.push(TxIn {
3044 previous_output: BitcoinOutPoint {
3048 script_sig: Script::new(),
3049 sequence: 0xfffffffd,
3050 witness: Vec::new(),
3053 claim_tx.output.push(TxOut {
3054 script_pubkey: script_pubkey.clone(),
3057 let base_weight = claim_tx.get_weight();
3058 let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC];
3059 let mut inputs_total_weight = 2; // count segwit flags
3061 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3062 for (idx, inp) in inputs_weight.iter().enumerate() {
3063 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3064 inputs_total_weight += inp;
3067 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3069 // Claim tx with 1 offered HTLCs, 3 received HTLCs
3070 claim_tx.input.clear();
3071 sum_actual_sigs = 0;
3073 claim_tx.input.push(TxIn {
3074 previous_output: BitcoinOutPoint {
3078 script_sig: Script::new(),
3079 sequence: 0xfffffffd,
3080 witness: Vec::new(),
3083 let base_weight = claim_tx.get_weight();
3084 let inputs_weight = vec![WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_RECEIVED_HTLC];
3085 let mut inputs_total_weight = 2; // count segwit flags
3087 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3088 for (idx, inp) in inputs_weight.iter().enumerate() {
3089 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3090 inputs_total_weight += inp;
3093 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_weight.len() - sum_actual_sigs));
3095 // Justice tx with 1 revoked HTLC-Success tx output
3096 claim_tx.input.clear();
3097 sum_actual_sigs = 0;
3098 claim_tx.input.push(TxIn {
3099 previous_output: BitcoinOutPoint {
3103 script_sig: Script::new(),
3104 sequence: 0xfffffffd,
3105 witness: Vec::new(),
3107 let base_weight = claim_tx.get_weight();
3108 let inputs_weight = vec![WEIGHT_REVOKED_OUTPUT];
3109 let mut inputs_total_weight = 2; // count segwit flags
3111 let mut sighash_parts = bip143::SigHashCache::new(&mut claim_tx);
3112 for (idx, inp) in inputs_weight.iter().enumerate() {
3113 sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
3114 inputs_total_weight += inp;
3117 assert_eq!(base_weight + inputs_total_weight as usize, claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_weight.len() - sum_actual_sigs));
3120 // Further testing is done in the ChannelManager integration tests.