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[rust-lightning] / src / ln / channelmonitor.rs
1 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
2 //! here.
3 //!
4 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
5 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
6 //! be made in responding to certain messages, see ManyChannelMonitor for more.
7 //!
8 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
9 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
10 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
11 //! security-domain-separated system design, you should consider having multiple paths for
12 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
13
14 use bitcoin::blockdata::block::BlockHeader;
15 use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction};
16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
17 use bitcoin::blockdata::script::{Script, Builder};
18 use bitcoin::blockdata::opcodes;
19 use bitcoin::consensus::encode::{self, Decodable, Encodable};
20 use bitcoin::util::hash::BitcoinHash;
21 use bitcoin::util::bip143;
22
23 use bitcoin_hashes::Hash;
24 use bitcoin_hashes::sha256::Hash as Sha256;
25 use bitcoin_hashes::hash160::Hash as Hash160;
26 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
27
28 use secp256k1::{Secp256k1,Signature};
29 use secp256k1::key::{SecretKey,PublicKey};
30 use secp256k1;
31
32 use ln::msgs::DecodeError;
33 use ln::chan_utils;
34 use ln::chan_utils::HTLCOutputInCommitment;
35 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
36 use ln::channel::{ACCEPTED_HTLC_SCRIPT_WEIGHT, OFFERED_HTLC_SCRIPT_WEIGHT};
37 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
38 use chain::transaction::OutPoint;
39 use chain::keysinterface::SpendableOutputDescriptor;
40 use util::logger::Logger;
41 use util::ser::{ReadableArgs, Readable, Writer, Writeable, WriterWriteAdaptor, U48};
42 use util::{byte_utils, events};
43
44 use std::collections::{HashMap, hash_map};
45 use std::sync::{Arc,Mutex};
46 use std::{hash,cmp, mem};
47
48 /// An error enum representing a failure to persist a channel monitor update.
49 #[derive(Clone)]
50 pub enum ChannelMonitorUpdateErr {
51         /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
52         /// our state failed, but is expected to succeed at some point in the future).
53         ///
54         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
55         /// submitting new commitment transactions to the remote party.
56         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
57         /// the channel to an operational state.
58         ///
59         /// Note that continuing to operate when no copy of the updated ChannelMonitor could be
60         /// persisted is unsafe - if you failed to store the update on your own local disk you should
61         /// instead return PermanentFailure to force closure of the channel ASAP.
62         ///
63         /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
64         /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
65         /// to claim it on this channel) and those updates must be applied wherever they can be. At
66         /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
67         /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
68         /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
69         /// been "frozen".
70         ///
71         /// Note that even if updates made after TemporaryFailure succeed you must still call
72         /// test_restore_channel_monitor to ensure you have the latest monitor and re-enable normal
73         /// channel operation.
74         ///
75         /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
76         /// remote location (with local copies persisted immediately), it is anticipated that all
77         /// updates will return TemporaryFailure until the remote copies could be updated.
78         TemporaryFailure,
79         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
80         /// different watchtower and cannot update with all watchtowers that were previously informed
81         /// of this channel). This will force-close the channel in question.
82         ///
83         /// Should also be used to indicate a failure to update the local copy of the channel monitor.
84         PermanentFailure,
85 }
86
87 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
88 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::insert_combine this
89 /// means you tried to merge two monitors for different channels or for a channel which was
90 /// restored from a backup and then generated new commitment updates.
91 /// Contains a human-readable error message.
92 #[derive(Debug)]
93 pub struct MonitorUpdateError(pub &'static str);
94
95 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
96 /// forward channel and from which info are needed to update HTLC in a backward channel.
97 pub struct HTLCUpdate {
98         pub(super) payment_hash: PaymentHash,
99         pub(super) payment_preimage: Option<PaymentPreimage>,
100         pub(super) source: HTLCSource
101 }
102
103 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
104 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
105 /// events to it, while also taking any add_update_monitor events and passing them to some remote
106 /// server(s).
107 ///
108 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
109 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
110 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
111 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
112 pub trait ManyChannelMonitor: Send + Sync {
113         /// Adds or updates a monitor for the given `funding_txo`.
114         ///
115         /// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
116         /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
117         /// any spends of it.
118         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
119
120         /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
121         /// with success or failure backward
122         fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate>;
123 }
124
125 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
126 /// watchtower or watch our own channels.
127 ///
128 /// Note that you must provide your own key by which to refer to channels.
129 ///
130 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
131 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
132 /// index by a PublicKey which is required to sign any updates.
133 ///
134 /// If you're using this for local monitoring of your own channels, you probably want to use
135 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
136 pub struct SimpleManyChannelMonitor<Key> {
137         #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
138         pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
139         #[cfg(not(test))]
140         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
141         chain_monitor: Arc<ChainWatchInterface>,
142         broadcaster: Arc<BroadcasterInterface>,
143         pending_events: Mutex<Vec<events::Event>>,
144         pending_htlc_updated: Mutex<HashMap<PaymentHash, Vec<(HTLCSource, Option<PaymentPreimage>)>>>,
145         logger: Arc<Logger>,
146 }
147
148 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
149         fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
150                 let block_hash = header.bitcoin_hash();
151                 let mut new_events: Vec<events::Event> = Vec::with_capacity(0);
152                 let mut htlc_updated_infos = Vec::new();
153                 {
154                         let mut monitors = self.monitors.lock().unwrap();
155                         for monitor in monitors.values_mut() {
156                                 let (txn_outputs, spendable_outputs, mut htlc_updated) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster);
157                                 if spendable_outputs.len() > 0 {
158                                         new_events.push(events::Event::SpendableOutputs {
159                                                 outputs: spendable_outputs,
160                                         });
161                                 }
162
163                                 for (ref txid, ref outputs) in txn_outputs {
164                                         for (idx, output) in outputs.iter().enumerate() {
165                                                 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
166                                         }
167                                 }
168                                 htlc_updated_infos.append(&mut htlc_updated);
169                         }
170                 }
171                 {
172                         // ChannelManager will just need to fetch pending_htlc_updated and pass state backward
173                         let mut pending_htlc_updated = self.pending_htlc_updated.lock().unwrap();
174                         for htlc in htlc_updated_infos.drain(..) {
175                                 match pending_htlc_updated.entry(htlc.2) {
176                                         hash_map::Entry::Occupied(mut e) => {
177                                                 // In case of reorg we may have htlc outputs solved in a different way so
178                                                 // we prefer to keep claims but don't store duplicate updates for a given
179                                                 // (payment_hash, HTLCSource) pair.
180                                                 // TODO: Note that we currently don't really use this as ChannelManager
181                                                 // will fail/claim backwards after the first block. We really should delay
182                                                 // a few blocks before failing backwards (but can claim backwards
183                                                 // immediately) as long as we have a few blocks of headroom.
184                                                 let mut existing_claim = false;
185                                                 e.get_mut().retain(|htlc_data| {
186                                                         if htlc.0 == htlc_data.0 {
187                                                                 if htlc_data.1.is_some() {
188                                                                         existing_claim = true;
189                                                                         true
190                                                                 } else { false }
191                                                         } else { true }
192                                                 });
193                                                 if !existing_claim {
194                                                         e.get_mut().push((htlc.0, htlc.1));
195                                                 }
196                                         }
197                                         hash_map::Entry::Vacant(e) => {
198                                                 e.insert(vec![(htlc.0, htlc.1)]);
199                                         }
200                                 }
201                         }
202                 }
203                 let mut pending_events = self.pending_events.lock().unwrap();
204                 pending_events.append(&mut new_events);
205         }
206
207         fn block_disconnected(&self, _: &BlockHeader) { }
208 }
209
210 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
211         /// Creates a new object which can be used to monitor several channels given the chain
212         /// interface with which to register to receive notifications.
213         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>, logger: Arc<Logger>) -> Arc<SimpleManyChannelMonitor<Key>> {
214                 let res = Arc::new(SimpleManyChannelMonitor {
215                         monitors: Mutex::new(HashMap::new()),
216                         chain_monitor,
217                         broadcaster,
218                         pending_events: Mutex::new(Vec::new()),
219                         pending_htlc_updated: Mutex::new(HashMap::new()),
220                         logger,
221                 });
222                 let weak_res = Arc::downgrade(&res);
223                 res.chain_monitor.register_listener(weak_res);
224                 res
225         }
226
227         /// Adds or updates the monitor which monitors the channel referred to by the given key.
228         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), MonitorUpdateError> {
229                 let mut monitors = self.monitors.lock().unwrap();
230                 match monitors.get_mut(&key) {
231                         Some(orig_monitor) => {
232                                 log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(monitor.key_storage));
233                                 return orig_monitor.insert_combine(monitor);
234                         },
235                         None => {}
236                 };
237                 match monitor.key_storage {
238                         Storage::Local { ref funding_info, .. } => {
239                                 match funding_info {
240                                         &None => {
241                                                 return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !"));
242                                         },
243                                         &Some((ref outpoint, ref script)) => {
244                                                 log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..]));
245                                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
246                                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
247                                         },
248                                 }
249                         },
250                         Storage::Watchtower { .. } => {
251                                 self.chain_monitor.watch_all_txn();
252                         }
253                 }
254                 monitors.insert(key, monitor);
255                 Ok(())
256         }
257 }
258
259 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
260         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
261                 match self.add_update_monitor_by_key(funding_txo, monitor) {
262                         Ok(_) => Ok(()),
263                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
264                 }
265         }
266
267         fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate> {
268                 let mut updated = self.pending_htlc_updated.lock().unwrap();
269                 let mut pending_htlcs_updated = Vec::with_capacity(updated.len());
270                 for (k, v) in updated.drain() {
271                         for htlc_data in v {
272                                 pending_htlcs_updated.push(HTLCUpdate {
273                                         payment_hash: k,
274                                         payment_preimage: htlc_data.1,
275                                         source: htlc_data.0,
276                                 });
277                         }
278                 }
279                 pending_htlcs_updated
280         }
281 }
282
283 impl<Key : Send + cmp::Eq + hash::Hash> events::EventsProvider for SimpleManyChannelMonitor<Key> {
284         fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
285                 let mut pending_events = self.pending_events.lock().unwrap();
286                 let mut ret = Vec::new();
287                 mem::swap(&mut ret, &mut *pending_events);
288                 ret
289         }
290 }
291
292 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
293 /// instead claiming it in its own individual transaction.
294 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
295 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
296 /// HTLC-Success transaction.
297 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
298 /// transaction confirmed (and we use it in a few more, equivalent, places).
299 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
300 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
301 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
302 /// copies of ChannelMonitors, including watchtowers).
303 pub(crate) const HTLC_FAIL_TIMEOUT_BLOCKS: u32 = 3;
304 /// Number of blocks we wait on seeing a confirmed HTLC-Timeout or previous revoked commitment
305 /// transaction before we fail corresponding inbound HTLCs. This prevents us from failing backwards
306 /// and then getting a reorg resulting in us losing money.
307 //TODO: We currently don't actually use this...we should
308 pub(crate) const HTLC_FAIL_ANTI_REORG_DELAY: u32 = 6;
309
310 #[derive(Clone, PartialEq)]
311 enum Storage {
312         Local {
313                 revocation_base_key: SecretKey,
314                 htlc_base_key: SecretKey,
315                 delayed_payment_base_key: SecretKey,
316                 payment_base_key: SecretKey,
317                 shutdown_pubkey: PublicKey,
318                 prev_latest_per_commitment_point: Option<PublicKey>,
319                 latest_per_commitment_point: Option<PublicKey>,
320                 funding_info: Option<(OutPoint, Script)>,
321                 current_remote_commitment_txid: Option<Sha256dHash>,
322                 prev_remote_commitment_txid: Option<Sha256dHash>,
323         },
324         Watchtower {
325                 revocation_base_key: PublicKey,
326                 htlc_base_key: PublicKey,
327         }
328 }
329
330 #[derive(Clone, PartialEq)]
331 struct LocalSignedTx {
332         /// txid of the transaction in tx, just used to make comparison faster
333         txid: Sha256dHash,
334         tx: Transaction,
335         revocation_key: PublicKey,
336         a_htlc_key: PublicKey,
337         b_htlc_key: PublicKey,
338         delayed_payment_key: PublicKey,
339         feerate_per_kw: u64,
340         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<(Signature, Signature)>, Option<HTLCSource>)>,
341 }
342
343 const SERIALIZATION_VERSION: u8 = 1;
344 const MIN_SERIALIZATION_VERSION: u8 = 1;
345
346 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
347 /// on-chain transactions to ensure no loss of funds occurs.
348 ///
349 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
350 /// information and are actively monitoring the chain.
351 #[derive(Clone)]
352 pub struct ChannelMonitor {
353         commitment_transaction_number_obscure_factor: u64,
354
355         key_storage: Storage,
356         their_htlc_base_key: Option<PublicKey>,
357         their_delayed_payment_base_key: Option<PublicKey>,
358         // first is the idx of the first of the two revocation points
359         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
360
361         our_to_self_delay: u16,
362         their_to_self_delay: Option<u16>,
363
364         old_secrets: [([u8; 32], u64); 49],
365         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
366         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
367         /// Nor can we figure out their commitment numbers without the commitment transaction they are
368         /// spending. Thus, in order to claim them via revocation key, we track all the remote
369         /// commitment transactions which we find on-chain, mapping them to the commitment number which
370         /// can be used to derive the revocation key and claim the transactions.
371         remote_commitment_txn_on_chain: HashMap<Sha256dHash, (u64, Vec<Script>)>,
372         /// Cache used to make pruning of payment_preimages faster.
373         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
374         /// remote transactions (ie should remain pretty small).
375         /// Serialized to disk but should generally not be sent to Watchtowers.
376         remote_hash_commitment_number: HashMap<PaymentHash, u64>,
377
378         // We store two local commitment transactions to avoid any race conditions where we may update
379         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
380         // various monitors for one channel being out of sync, and us broadcasting a local
381         // transaction for which we have deleted claim information on some watchtowers.
382         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
383         current_local_signed_commitment_tx: Option<LocalSignedTx>,
384
385         // Used just for ChannelManager to make sure it has the latest channel data during
386         // deserialization
387         current_remote_commitment_number: u64,
388
389         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
390
391         destination_script: Script,
392
393         // We simply modify last_block_hash in Channel's block_connected so that serialization is
394         // consistent but hopefully the users' copy handles block_connected in a consistent way.
395         // (we do *not*, however, update them in insert_combine to ensure any local user copies keep
396         // their last_block_hash from its state and not based on updated copies that didn't run through
397         // the full block_connected).
398         pub(crate) last_block_hash: Sha256dHash,
399         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
400         logger: Arc<Logger>,
401 }
402
403 #[cfg(any(test, feature = "fuzztarget"))]
404 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
405 /// underlying object
406 impl PartialEq for ChannelMonitor {
407         fn eq(&self, other: &Self) -> bool {
408                 if self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
409                         self.key_storage != other.key_storage ||
410                         self.their_htlc_base_key != other.their_htlc_base_key ||
411                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
412                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
413                         self.our_to_self_delay != other.our_to_self_delay ||
414                         self.their_to_self_delay != other.their_to_self_delay ||
415                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
416                         self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
417                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
418                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
419                         self.current_remote_commitment_number != other.current_remote_commitment_number ||
420                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
421                         self.payment_preimages != other.payment_preimages ||
422                         self.destination_script != other.destination_script
423                 {
424                         false
425                 } else {
426                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
427                                 if secret != o_secret || idx != o_idx {
428                                         return false
429                                 }
430                         }
431                         true
432                 }
433         }
434 }
435
436 impl ChannelMonitor {
437         pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, payment_base_key: &SecretKey, shutdown_pubkey: &PublicKey, our_to_self_delay: u16, destination_script: Script, logger: Arc<Logger>) -> ChannelMonitor {
438                 ChannelMonitor {
439                         commitment_transaction_number_obscure_factor: 0,
440
441                         key_storage: Storage::Local {
442                                 revocation_base_key: revocation_base_key.clone(),
443                                 htlc_base_key: htlc_base_key.clone(),
444                                 delayed_payment_base_key: delayed_payment_base_key.clone(),
445                                 payment_base_key: payment_base_key.clone(),
446                                 shutdown_pubkey: shutdown_pubkey.clone(),
447                                 prev_latest_per_commitment_point: None,
448                                 latest_per_commitment_point: None,
449                                 funding_info: None,
450                                 current_remote_commitment_txid: None,
451                                 prev_remote_commitment_txid: None,
452                         },
453                         their_htlc_base_key: None,
454                         their_delayed_payment_base_key: None,
455                         their_cur_revocation_points: None,
456
457                         our_to_self_delay: our_to_self_delay,
458                         their_to_self_delay: None,
459
460                         old_secrets: [([0; 32], 1 << 48); 49],
461                         remote_claimable_outpoints: HashMap::new(),
462                         remote_commitment_txn_on_chain: HashMap::new(),
463                         remote_hash_commitment_number: HashMap::new(),
464
465                         prev_local_signed_commitment_tx: None,
466                         current_local_signed_commitment_tx: None,
467                         current_remote_commitment_number: 1 << 48,
468
469                         payment_preimages: HashMap::new(),
470                         destination_script: destination_script,
471
472                         last_block_hash: Default::default(),
473                         secp_ctx: Secp256k1::new(),
474                         logger,
475                 }
476         }
477
478         #[inline]
479         fn place_secret(idx: u64) -> u8 {
480                 for i in 0..48 {
481                         if idx & (1 << i) == (1 << i) {
482                                 return i
483                         }
484                 }
485                 48
486         }
487
488         #[inline]
489         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
490                 let mut res: [u8; 32] = secret;
491                 for i in 0..bits {
492                         let bitpos = bits - 1 - i;
493                         if idx & (1 << bitpos) == (1 << bitpos) {
494                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
495                                 res = Sha256::hash(&res).into_inner();
496                         }
497                 }
498                 res
499         }
500
501         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
502         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
503         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
504         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
505                 let pos = ChannelMonitor::place_secret(idx);
506                 for i in 0..pos {
507                         let (old_secret, old_idx) = self.old_secrets[i as usize];
508                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
509                                 return Err(MonitorUpdateError("Previous secret did not match new one"));
510                         }
511                 }
512                 if self.get_min_seen_secret() <= idx {
513                         return Ok(());
514                 }
515                 self.old_secrets[pos as usize] = (secret, idx);
516
517                 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
518                 // events for now-revoked/fulfilled HTLCs.
519                 // TODO: We should probably consider whether we're really getting the next secret here.
520                 if let Storage::Local { ref mut prev_remote_commitment_txid, .. } = self.key_storage {
521                         if let Some(txid) = prev_remote_commitment_txid.take() {
522                                 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
523                                         *source = None;
524                                 }
525                         }
526                 }
527
528                 if !self.payment_preimages.is_empty() {
529                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
530                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
531                         let min_idx = self.get_min_seen_secret();
532                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
533
534                         self.payment_preimages.retain(|&k, _| {
535                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
536                                         if k == htlc.payment_hash {
537                                                 return true
538                                         }
539                                 }
540                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
541                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
542                                                 if k == htlc.payment_hash {
543                                                         return true
544                                                 }
545                                         }
546                                 }
547                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
548                                         if *cn < min_idx {
549                                                 return true
550                                         }
551                                         true
552                                 } else { false };
553                                 if contains {
554                                         remote_hash_commitment_number.remove(&k);
555                                 }
556                                 false
557                         });
558                 }
559
560                 Ok(())
561         }
562
563         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
564         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
565         /// possibly future revocation/preimage information) to claim outputs where possible.
566         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
567         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey) {
568                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
569                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
570                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
571                 // timeouts)
572                 for &(ref htlc, _) in &htlc_outputs {
573                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
574                 }
575
576                 let new_txid = unsigned_commitment_tx.txid();
577                 log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
578                 log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
579                 if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage {
580                         *prev_remote_commitment_txid = current_remote_commitment_txid.take();
581                         *current_remote_commitment_txid = Some(new_txid);
582                 }
583                 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
584                 self.current_remote_commitment_number = commitment_number;
585                 //TODO: Merge this into the other per-remote-transaction output storage stuff
586                 match self.their_cur_revocation_points {
587                         Some(old_points) => {
588                                 if old_points.0 == commitment_number + 1 {
589                                         self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
590                                 } else if old_points.0 == commitment_number + 2 {
591                                         if let Some(old_second_point) = old_points.2 {
592                                                 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
593                                         } else {
594                                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
595                                         }
596                                 } else {
597                                         self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
598                                 }
599                         },
600                         None => {
601                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
602                         }
603                 }
604         }
605
606         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
607         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
608         /// is important that any clones of this channel monitor (including remote clones) by kept
609         /// up-to-date as our local commitment transaction is updated.
610         /// Panics if set_their_to_self_delay has never been called.
611         /// Also update Storage with latest local per_commitment_point to derive local_delayedkey in
612         /// case of onchain HTLC tx
613         pub(super) fn provide_latest_local_commitment_tx_info(&mut self, signed_commitment_tx: Transaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<(Signature, Signature)>, Option<HTLCSource>)>) {
614                 assert!(self.their_to_self_delay.is_some());
615                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
616                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
617                         txid: signed_commitment_tx.txid(),
618                         tx: signed_commitment_tx,
619                         revocation_key: local_keys.revocation_key,
620                         a_htlc_key: local_keys.a_htlc_key,
621                         b_htlc_key: local_keys.b_htlc_key,
622                         delayed_payment_key: local_keys.a_delayed_payment_key,
623                         feerate_per_kw,
624                         htlc_outputs,
625                 });
626
627                 if let Storage::Local { ref mut latest_per_commitment_point, .. } = self.key_storage {
628                         *latest_per_commitment_point = Some(local_keys.per_commitment_point);
629                 } else {
630                         panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
631                 }
632         }
633
634         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
635         /// commitment_tx_infos which contain the payment hash have been revoked.
636         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
637                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
638         }
639
640         /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
641         /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
642         /// chain for new blocks/transactions.
643         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), MonitorUpdateError> {
644                 match self.key_storage {
645                         Storage::Local { ref funding_info, .. } => {
646                                 if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
647                                 let our_funding_info = funding_info;
648                                 if let Storage::Local { ref funding_info, .. } = other.key_storage {
649                                         if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
650                                         // We should be able to compare the entire funding_txo, but in fuzztarget it's trivially
651                                         // easy to collide the funding_txo hash and have a different scriptPubKey.
652                                         if funding_info.as_ref().unwrap().0 != our_funding_info.as_ref().unwrap().0 {
653                                                 return Err(MonitorUpdateError("Funding transaction outputs are not identical!"));
654                                         }
655                                 } else {
656                                         return Err(MonitorUpdateError("Try to combine a Local monitor with a Watchtower one !"));
657                                 }
658                         },
659                         Storage::Watchtower { .. } => {
660                                 if let Storage::Watchtower { .. } = other.key_storage {
661                                         unimplemented!();
662                                 } else {
663                                         return Err(MonitorUpdateError("Try to combine a Watchtower monitor with a Local one !"));
664                                 }
665                         },
666                 }
667                 let other_min_secret = other.get_min_seen_secret();
668                 let our_min_secret = self.get_min_seen_secret();
669                 if our_min_secret > other_min_secret {
670                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap())?;
671                 }
672                 if let Some(ref local_tx) = self.current_local_signed_commitment_tx {
673                         if let Some(ref other_local_tx) = other.current_local_signed_commitment_tx {
674                                 let our_commitment_number = 0xffffffffffff - ((((local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
675                                 let other_commitment_number = 0xffffffffffff - ((((other_local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (other_local_tx.tx.lock_time as u64 & 0xffffff)) ^ other.commitment_transaction_number_obscure_factor);
676                                 if our_commitment_number >= other_commitment_number {
677                                         self.key_storage = other.key_storage;
678                                 }
679                         }
680                 }
681                 // TODO: We should use current_remote_commitment_number and the commitment number out of
682                 // local transactions to decide how to merge
683                 if our_min_secret >= other_min_secret {
684                         self.their_cur_revocation_points = other.their_cur_revocation_points;
685                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
686                                 self.remote_claimable_outpoints.insert(txid, htlcs);
687                         }
688                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
689                                 self.prev_local_signed_commitment_tx = Some(local_tx);
690                         }
691                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
692                                 self.current_local_signed_commitment_tx = Some(local_tx);
693                         }
694                         self.payment_preimages = other.payment_preimages;
695                 }
696
697                 self.current_remote_commitment_number = cmp::min(self.current_remote_commitment_number, other.current_remote_commitment_number);
698                 Ok(())
699         }
700
701         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
702         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
703                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
704                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
705         }
706
707         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
708         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
709         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
710         /// provides slightly better privacy.
711         /// It's the responsibility of the caller to register outpoint and script with passing the former
712         /// value as key to add_update_monitor.
713         pub(super) fn set_funding_info(&mut self, new_funding_info: (OutPoint, Script)) {
714                 match self.key_storage {
715                         Storage::Local { ref mut funding_info, .. } => {
716                                 *funding_info = Some(new_funding_info);
717                         },
718                         Storage::Watchtower { .. } => {
719                                 panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
720                         }
721                 }
722         }
723
724         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
725         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
726                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
727                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
728         }
729
730         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
731                 self.their_to_self_delay = Some(their_to_self_delay);
732         }
733
734         pub(super) fn unset_funding_info(&mut self) {
735                 match self.key_storage {
736                         Storage::Local { ref mut funding_info, .. } => {
737                                 *funding_info = None;
738                         },
739                         Storage::Watchtower { .. } => {
740                                 panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
741                         },
742                 }
743         }
744
745         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
746         pub fn get_funding_txo(&self) -> Option<OutPoint> {
747                 match self.key_storage {
748                         Storage::Local { ref funding_info, .. } => {
749                                 match funding_info {
750                                         &Some((outpoint, _)) => Some(outpoint),
751                                         &None => None
752                                 }
753                         },
754                         Storage::Watchtower { .. } => {
755                                 return None;
756                         }
757                 }
758         }
759
760         /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
761         /// Generally useful when deserializing as during normal operation the return values of
762         /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
763         /// that the get_funding_txo outpoint and transaction must also be monitored for!).
764         pub fn get_monitored_outpoints(&self) -> Vec<(Sha256dHash, u32, &Script)> {
765                 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
766                 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
767                         for (idx, output) in outputs.iter().enumerate() {
768                                 res.push(((*txid).clone(), idx as u32, output));
769                         }
770                 }
771                 res
772         }
773
774         /// Serializes into a vec, with various modes for the exposed pub fns
775         fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
776                 //TODO: We still write out all the serialization here manually instead of using the fancy
777                 //serialization framework we have, we should migrate things over to it.
778                 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
779                 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
780
781                 // Set in initial Channel-object creation, so should always be set by now:
782                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
783
784                 macro_rules! write_option {
785                         ($thing: expr) => {
786                                 match $thing {
787                                         &Some(ref t) => {
788                                                 1u8.write(writer)?;
789                                                 t.write(writer)?;
790                                         },
791                                         &None => 0u8.write(writer)?,
792                                 }
793                         }
794                 }
795
796                 match self.key_storage {
797                         Storage::Local { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point, ref funding_info, ref current_remote_commitment_txid, ref prev_remote_commitment_txid } => {
798                                 writer.write_all(&[0; 1])?;
799                                 writer.write_all(&revocation_base_key[..])?;
800                                 writer.write_all(&htlc_base_key[..])?;
801                                 writer.write_all(&delayed_payment_base_key[..])?;
802                                 writer.write_all(&payment_base_key[..])?;
803                                 writer.write_all(&shutdown_pubkey.serialize())?;
804                                 if let Some(ref prev_latest_per_commitment_point) = *prev_latest_per_commitment_point {
805                                         writer.write_all(&[1; 1])?;
806                                         writer.write_all(&prev_latest_per_commitment_point.serialize())?;
807                                 } else {
808                                         writer.write_all(&[0; 1])?;
809                                 }
810                                 if let Some(ref latest_per_commitment_point) = *latest_per_commitment_point {
811                                         writer.write_all(&[1; 1])?;
812                                         writer.write_all(&latest_per_commitment_point.serialize())?;
813                                 } else {
814                                         writer.write_all(&[0; 1])?;
815                                 }
816                                 match funding_info  {
817                                         &Some((ref outpoint, ref script)) => {
818                                                 writer.write_all(&outpoint.txid[..])?;
819                                                 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
820                                                 script.write(writer)?;
821                                         },
822                                         &None => {
823                                                 debug_assert!(false, "Try to serialize a useless Local monitor !");
824                                         },
825                                 }
826                                 write_option!(current_remote_commitment_txid);
827                                 write_option!(prev_remote_commitment_txid);
828                         },
829                         Storage::Watchtower { .. } => unimplemented!(),
830                 }
831
832                 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
833                 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
834
835                 match self.their_cur_revocation_points {
836                         Some((idx, pubkey, second_option)) => {
837                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
838                                 writer.write_all(&pubkey.serialize())?;
839                                 match second_option {
840                                         Some(second_pubkey) => {
841                                                 writer.write_all(&second_pubkey.serialize())?;
842                                         },
843                                         None => {
844                                                 writer.write_all(&[0; 33])?;
845                                         },
846                                 }
847                         },
848                         None => {
849                                 writer.write_all(&byte_utils::be48_to_array(0))?;
850                         },
851                 }
852
853                 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
854                 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
855
856                 for &(ref secret, ref idx) in self.old_secrets.iter() {
857                         writer.write_all(secret)?;
858                         writer.write_all(&byte_utils::be64_to_array(*idx))?;
859                 }
860
861                 macro_rules! serialize_htlc_in_commitment {
862                         ($htlc_output: expr) => {
863                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
864                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
865                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
866                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
867                                 write_option!(&$htlc_output.transaction_output_index);
868                         }
869                 }
870
871                 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
872                 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
873                         writer.write_all(&txid[..])?;
874                         writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
875                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
876                                 serialize_htlc_in_commitment!(htlc_output);
877                                 write_option!(htlc_source);
878                         }
879                 }
880
881                 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
882                 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
883                         writer.write_all(&txid[..])?;
884                         writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
885                         (txouts.len() as u64).write(writer)?;
886                         for script in txouts.iter() {
887                                 script.write(writer)?;
888                         }
889                 }
890
891                 if for_local_storage {
892                         writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
893                         for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
894                                 writer.write_all(&payment_hash.0[..])?;
895                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
896                         }
897                 } else {
898                         writer.write_all(&byte_utils::be64_to_array(0))?;
899                 }
900
901                 macro_rules! serialize_local_tx {
902                         ($local_tx: expr) => {
903                                 if let Err(e) = $local_tx.tx.consensus_encode(&mut WriterWriteAdaptor(writer)) {
904                                         match e {
905                                                 encode::Error::Io(e) => return Err(e),
906                                                 _ => panic!("local tx must have been well-formed!"),
907                                         }
908                                 }
909
910                                 writer.write_all(&$local_tx.revocation_key.serialize())?;
911                                 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
912                                 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
913                                 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
914
915                                 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
916                                 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
917                                 for &(ref htlc_output, ref sigs, ref htlc_source) in $local_tx.htlc_outputs.iter() {
918                                         serialize_htlc_in_commitment!(htlc_output);
919                                         if let &Some((ref their_sig, ref our_sig)) = sigs {
920                                                 1u8.write(writer)?;
921                                                 writer.write_all(&their_sig.serialize_compact())?;
922                                                 writer.write_all(&our_sig.serialize_compact())?;
923                                         } else {
924                                                 0u8.write(writer)?;
925                                         }
926                                         write_option!(htlc_source);
927                                 }
928                         }
929                 }
930
931                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
932                         writer.write_all(&[1; 1])?;
933                         serialize_local_tx!(prev_local_tx);
934                 } else {
935                         writer.write_all(&[0; 1])?;
936                 }
937
938                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
939                         writer.write_all(&[1; 1])?;
940                         serialize_local_tx!(cur_local_tx);
941                 } else {
942                         writer.write_all(&[0; 1])?;
943                 }
944
945                 if for_local_storage {
946                         writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
947                 } else {
948                         writer.write_all(&byte_utils::be48_to_array(0))?;
949                 }
950
951                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
952                 for payment_preimage in self.payment_preimages.values() {
953                         writer.write_all(&payment_preimage.0[..])?;
954                 }
955
956                 self.last_block_hash.write(writer)?;
957                 self.destination_script.write(writer)?;
958
959                 Ok(())
960         }
961
962         /// Writes this monitor into the given writer, suitable for writing to disk.
963         ///
964         /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
965         /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
966         /// the "reorg path" (ie not just starting at the same height but starting at the highest
967         /// common block that appears on your best chain as well as on the chain which contains the
968         /// last block hash returned) upon deserializing the object!
969         pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
970                 self.write(writer, true)
971         }
972
973         /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
974         ///
975         /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
976         /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
977         /// the "reorg path" (ie not just starting at the same height but starting at the highest
978         /// common block that appears on your best chain as well as on the chain which contains the
979         /// last block hash returned) upon deserializing the object!
980         pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
981                 self.write(writer, false)
982         }
983
984         /// Can only fail if idx is < get_min_seen_secret
985         pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
986                 for i in 0..self.old_secrets.len() {
987                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
988                                 return Some(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
989                         }
990                 }
991                 assert!(idx < self.get_min_seen_secret());
992                 None
993         }
994
995         pub(super) fn get_min_seen_secret(&self) -> u64 {
996                 //TODO This can be optimized?
997                 let mut min = 1 << 48;
998                 for &(_, idx) in self.old_secrets.iter() {
999                         if idx < min {
1000                                 min = idx;
1001                         }
1002                 }
1003                 min
1004         }
1005
1006         pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1007                 self.current_remote_commitment_number
1008         }
1009
1010         pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1011                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1012                         0xffff_ffff_ffff - ((((local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor)
1013                 } else { 0xffff_ffff_ffff }
1014         }
1015
1016         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1017         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1018         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1019         /// HTLC-Success/HTLC-Timeout transactions.
1020         /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1021         /// revoked remote commitment tx
1022         fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>), Vec<SpendableOutputDescriptor>, Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)>)  {
1023                 // Most secp and related errors trying to create keys means we have no hope of constructing
1024                 // a spend transaction...so we return no transactions to broadcast
1025                 let mut txn_to_broadcast = Vec::new();
1026                 let mut watch_outputs = Vec::new();
1027                 let mut spendable_outputs = Vec::new();
1028                 let mut htlc_updated = Vec::new();
1029
1030                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1031                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1032
1033                 macro_rules! ignore_error {
1034                         ( $thing : expr ) => {
1035                                 match $thing {
1036                                         Ok(a) => a,
1037                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated)
1038                                 }
1039                         };
1040                 }
1041
1042                 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);
1043                 if commitment_number >= self.get_min_seen_secret() {
1044                         let secret = self.get_secret(commitment_number).unwrap();
1045                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1046                         let (revocation_pubkey, b_htlc_key, local_payment_key) = match self.key_storage {
1047                                 Storage::Local { ref revocation_base_key, ref htlc_base_key, ref payment_base_key, .. } => {
1048                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1049                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1050                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))),
1051                                         Some(ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &payment_base_key))))
1052                                 },
1053                                 Storage::Watchtower { ref revocation_base_key, ref htlc_base_key, .. } => {
1054                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1055                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
1056                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)),
1057                                         None)
1058                                 },
1059                         };
1060                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
1061                         let a_htlc_key = match self.their_htlc_base_key {
1062                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated),
1063                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
1064                         };
1065
1066                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1067                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1068
1069                         let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key {
1070                                 // Note that the Network here is ignored as we immediately drop the address for the
1071                                 // script_pubkey version.
1072                                 let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
1073                                 Some(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script())
1074                         } else { None };
1075
1076                         let mut total_value = 0;
1077                         let mut values = Vec::new();
1078                         let mut inputs = Vec::new();
1079                         let mut htlc_idxs = Vec::new();
1080
1081                         for (idx, outp) in tx.output.iter().enumerate() {
1082                                 if outp.script_pubkey == revokeable_p2wsh {
1083                                         inputs.push(TxIn {
1084                                                 previous_output: BitcoinOutPoint {
1085                                                         txid: commitment_txid,
1086                                                         vout: idx as u32,
1087                                                 },
1088                                                 script_sig: Script::new(),
1089                                                 sequence: 0xfffffffd,
1090                                                 witness: Vec::new(),
1091                                         });
1092                                         htlc_idxs.push(None);
1093                                         values.push(outp.value);
1094                                         total_value += outp.value;
1095                                 } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() {
1096                                         spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1097                                                 outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1098                                                 key: local_payment_key.unwrap(),
1099                                                 output: outp.clone(),
1100                                         });
1101                                 }
1102                         }
1103
1104                         macro_rules! sign_input {
1105                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
1106                                         {
1107                                                 let (sig, redeemscript) = match self.key_storage {
1108                                                         Storage::Local { ref revocation_base_key, .. } => {
1109                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
1110                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()].0;
1111                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
1112                                                                 };
1113                                                                 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
1114                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1115                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
1116                                                         },
1117                                                         Storage::Watchtower { .. } => {
1118                                                                 unimplemented!();
1119                                                         }
1120                                                 };
1121                                                 $input.witness.push(sig.serialize_der().to_vec());
1122                                                 $input.witness[0].push(SigHashType::All as u8);
1123                                                 if $htlc_idx.is_none() {
1124                                                         $input.witness.push(vec!(1));
1125                                                 } else {
1126                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
1127                                                 }
1128                                                 $input.witness.push(redeemscript.into_bytes());
1129                                         }
1130                                 }
1131                         }
1132
1133                         if let Some(ref per_commitment_data) = per_commitment_option {
1134                                 inputs.reserve_exact(per_commitment_data.len());
1135
1136                                 for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1137                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
1138                                                 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1139                                                 if transaction_output_index as usize >= tx.output.len() ||
1140                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1141                                                                 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1142                                                         return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user
1143                                                 }
1144                                                 let input = TxIn {
1145                                                         previous_output: BitcoinOutPoint {
1146                                                                 txid: commitment_txid,
1147                                                                 vout: transaction_output_index,
1148                                                         },
1149                                                         script_sig: Script::new(),
1150                                                         sequence: 0xfffffffd,
1151                                                         witness: Vec::new(),
1152                                                 };
1153                                                 if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1154                                                         inputs.push(input);
1155                                                         htlc_idxs.push(Some(idx));
1156                                                         values.push(tx.output[transaction_output_index as usize].value);
1157                                                         total_value += htlc.amount_msat / 1000;
1158                                                 } else {
1159                                                         let mut single_htlc_tx = Transaction {
1160                                                                 version: 2,
1161                                                                 lock_time: 0,
1162                                                                 input: vec![input],
1163                                                                 output: vec!(TxOut {
1164                                                                         script_pubkey: self.destination_script.clone(),
1165                                                                         value: htlc.amount_msat / 1000, //TODO: - fee
1166                                                                 }),
1167                                                         };
1168                                                         let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1169                                                         sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
1170                                                         txn_to_broadcast.push(single_htlc_tx);
1171                                                 }
1172                                         }
1173                                 }
1174                         }
1175
1176                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1177                                 // We're definitely a remote commitment transaction!
1178                                 log_trace!(self, "Got broadcast of revoked remote commitment transaction, generating general spend tx with {} inputs and {} other txn to broadcast", inputs.len(), txn_to_broadcast.len());
1179                                 watch_outputs.append(&mut tx.output.clone());
1180                                 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1181
1182                                 // TODO: We really should only fail backwards after our revocation claims have been
1183                                 // confirmed, but we also need to do more other tracking of in-flight pre-confirm
1184                                 // on-chain claims, so we can do that at the same time.
1185                                 macro_rules! check_htlc_fails {
1186                                         ($txid: expr, $commitment_tx: expr) => {
1187                                                 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1188                                                         for &(ref htlc, ref source_option) in outpoints.iter() {
1189                                                                 if let &Some(ref source) = source_option {
1190                                                                         log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1191                                                                         htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone()));
1192                                                                 }
1193                                                         }
1194                                                 }
1195                                         }
1196                                 }
1197                                 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1198                                         if let &Some(ref txid) = current_remote_commitment_txid {
1199                                                 check_htlc_fails!(txid, "current");
1200                                         }
1201                                         if let &Some(ref txid) = prev_remote_commitment_txid {
1202                                                 check_htlc_fails!(txid, "remote");
1203                                         }
1204                                 }
1205                                 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1206                         }
1207                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx
1208
1209                         let outputs = vec!(TxOut {
1210                                 script_pubkey: self.destination_script.clone(),
1211                                 value: total_value, //TODO: - fee
1212                         });
1213                         let mut spend_tx = Transaction {
1214                                 version: 2,
1215                                 lock_time: 0,
1216                                 input: inputs,
1217                                 output: outputs,
1218                         };
1219
1220                         let mut values_drain = values.drain(..);
1221                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1222
1223                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
1224                                 let value = values_drain.next().unwrap();
1225                                 sign_input!(sighash_parts, input, htlc_idx, value);
1226                         }
1227
1228                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1229                                 outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
1230                                 output: spend_tx.output[0].clone(),
1231                         });
1232                         txn_to_broadcast.push(spend_tx);
1233                 } else if let Some(per_commitment_data) = per_commitment_option {
1234                         // While this isn't useful yet, there is a potential race where if a counterparty
1235                         // revokes a state at the same time as the commitment transaction for that state is
1236                         // confirmed, and the watchtower receives the block before the user, the user could
1237                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
1238                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1239                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
1240                         // insert it here.
1241                         watch_outputs.append(&mut tx.output.clone());
1242                         self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1243
1244                         log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1245
1246                         // TODO: We really should only fail backwards after our revocation claims have been
1247                         // confirmed, but we also need to do more other tracking of in-flight pre-confirm
1248                         // on-chain claims, so we can do that at the same time.
1249                         macro_rules! check_htlc_fails {
1250                                 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1251                                         if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1252                                                 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1253                                                         if let &Some(ref source) = source_option {
1254                                                                 // Check if the HTLC is present in the commitment transaction that was
1255                                                                 // broadcast, but not if it was below the dust limit, which we should
1256                                                                 // fail backwards immediately as there is no way for us to learn the
1257                                                                 // payment_preimage.
1258                                                                 // Note that if the dust limit were allowed to change between
1259                                                                 // commitment transactions we'd want to be check whether *any*
1260                                                                 // broadcastable commitment transaction has the HTLC in it, but it
1261                                                                 // cannot currently change after channel initialization, so we don't
1262                                                                 // need to here.
1263                                                                 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1264                                                                         if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1265                                                                                 continue $id;
1266                                                                         }
1267                                                                 }
1268                                                                 log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1269                                                                 htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone()));
1270                                                         }
1271                                                 }
1272                                         }
1273                                 }
1274                         }
1275                         if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1276                                 if let &Some(ref txid) = current_remote_commitment_txid {
1277                                         check_htlc_fails!(txid, "current", 'current_loop);
1278                                 }
1279                                 if let &Some(ref txid) = prev_remote_commitment_txid {
1280                                         check_htlc_fails!(txid, "previous", 'prev_loop);
1281                                 }
1282                         }
1283
1284                         if let Some(revocation_points) = self.their_cur_revocation_points {
1285                                 let revocation_point_option =
1286                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1287                                         else if let Some(point) = revocation_points.2.as_ref() {
1288                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1289                                         } else { None };
1290                                 if let Some(revocation_point) = revocation_point_option {
1291                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
1292                                                 Storage::Local { ref revocation_base_key, ref htlc_base_key, .. } => {
1293                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1294                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
1295                                                 },
1296                                                 Storage::Watchtower { ref revocation_base_key, ref htlc_base_key, .. } => {
1297                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
1298                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1299                                                 },
1300                                         };
1301                                         let a_htlc_key = match self.their_htlc_base_key {
1302                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated),
1303                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1304                                         };
1305
1306                                         for (idx, outp) in tx.output.iter().enumerate() {
1307                                                 if outp.script_pubkey.is_v0_p2wpkh() {
1308                                                         match self.key_storage {
1309                                                                 Storage::Local { ref payment_base_key, .. } => {
1310                                                                         if let Ok(local_key) = chan_utils::derive_private_key(&self.secp_ctx, &revocation_point, &payment_base_key) {
1311                                                                                 spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1312                                                                                         outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1313                                                                                         key: local_key,
1314                                                                                         output: outp.clone(),
1315                                                                                 });
1316                                                                         }
1317                                                                 },
1318                                                                 Storage::Watchtower { .. } => {}
1319                                                         }
1320                                                         break; // Only to_remote ouput is claimable
1321                                                 }
1322                                         }
1323
1324                                         let mut total_value = 0;
1325                                         let mut values = Vec::new();
1326                                         let mut inputs = Vec::new();
1327
1328                                         macro_rules! sign_input {
1329                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
1330                                                         {
1331                                                                 let (sig, redeemscript) = match self.key_storage {
1332                                                                         Storage::Local { ref htlc_base_key, .. } => {
1333                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize].0;
1334                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1335                                                                                 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
1336                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
1337                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
1338                                                                         },
1339                                                                         Storage::Watchtower { .. } => {
1340                                                                                 unimplemented!();
1341                                                                         }
1342                                                                 };
1343                                                                 $input.witness.push(sig.serialize_der().to_vec());
1344                                                                 $input.witness[0].push(SigHashType::All as u8);
1345                                                                 $input.witness.push($preimage);
1346                                                                 $input.witness.push(redeemscript.into_bytes());
1347                                                         }
1348                                                 }
1349                                         }
1350
1351                                         for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1352                                                 if let Some(transaction_output_index) = htlc.transaction_output_index {
1353                                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1354                                                         if transaction_output_index as usize >= tx.output.len() ||
1355                                                                         tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1356                                                                         tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1357                                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user
1358                                                         }
1359                                                         if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1360                                                                 let input = TxIn {
1361                                                                         previous_output: BitcoinOutPoint {
1362                                                                                 txid: commitment_txid,
1363                                                                                 vout: transaction_output_index,
1364                                                                         },
1365                                                                         script_sig: Script::new(),
1366                                                                         sequence: idx as u32, // reset to 0xfffffffd in sign_input
1367                                                                         witness: Vec::new(),
1368                                                                 };
1369                                                                 if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1370                                                                         inputs.push(input);
1371                                                                         values.push((tx.output[transaction_output_index as usize].value, payment_preimage));
1372                                                                         total_value += htlc.amount_msat / 1000;
1373                                                                 } else {
1374                                                                         let mut single_htlc_tx = Transaction {
1375                                                                                 version: 2,
1376                                                                                 lock_time: 0,
1377                                                                                 input: vec![input],
1378                                                                                 output: vec!(TxOut {
1379                                                                                         script_pubkey: self.destination_script.clone(),
1380                                                                                         value: htlc.amount_msat / 1000, //TODO: - fee
1381                                                                                 }),
1382                                                                         };
1383                                                                         let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1384                                                                         sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
1385                                                                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1386                                                                                 outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
1387                                                                                 output: single_htlc_tx.output[0].clone(),
1388                                                                         });
1389                                                                         txn_to_broadcast.push(single_htlc_tx);
1390                                                                 }
1391                                                         }
1392                                                         if !htlc.offered {
1393                                                                 // TODO: If the HTLC has already expired, potentially merge it with the
1394                                                                 // rest of the claim transaction, as above.
1395                                                                 let input = TxIn {
1396                                                                         previous_output: BitcoinOutPoint {
1397                                                                                 txid: commitment_txid,
1398                                                                                 vout: transaction_output_index,
1399                                                                         },
1400                                                                         script_sig: Script::new(),
1401                                                                         sequence: idx as u32,
1402                                                                         witness: Vec::new(),
1403                                                                 };
1404                                                                 let mut timeout_tx = Transaction {
1405                                                                         version: 2,
1406                                                                         lock_time: htlc.cltv_expiry,
1407                                                                         input: vec![input],
1408                                                                         output: vec!(TxOut {
1409                                                                                 script_pubkey: self.destination_script.clone(),
1410                                                                                 value: htlc.amount_msat / 1000,
1411                                                                         }),
1412                                                                 };
1413                                                                 let sighash_parts = bip143::SighashComponents::new(&timeout_tx);
1414                                                                 sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]);
1415                                                                 txn_to_broadcast.push(timeout_tx);
1416                                                         }
1417                                                 }
1418                                         }
1419
1420                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx
1421
1422                                         let outputs = vec!(TxOut {
1423                                                 script_pubkey: self.destination_script.clone(),
1424                                                 value: total_value, //TODO: - fee
1425                                         });
1426                                         let mut spend_tx = Transaction {
1427                                                 version: 2,
1428                                                 lock_time: 0,
1429                                                 input: inputs,
1430                                                 output: outputs,
1431                                         };
1432
1433                                         let mut values_drain = values.drain(..);
1434                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1435
1436                                         for input in spend_tx.input.iter_mut() {
1437                                                 let value = values_drain.next().unwrap();
1438                                                 sign_input!(sighash_parts, input, value.0, (value.1).0.to_vec());
1439                                         }
1440
1441                                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1442                                                 outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
1443                                                 output: spend_tx.output[0].clone(),
1444                                         });
1445                                         txn_to_broadcast.push(spend_tx);
1446                                 }
1447                         }
1448                 }
1449
1450                 (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated)
1451         }
1452
1453         /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1454         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> (Option<Transaction>, Option<SpendableOutputDescriptor>) {
1455                 if tx.input.len() != 1 || tx.output.len() != 1 {
1456                         return (None, None)
1457                 }
1458
1459                 macro_rules! ignore_error {
1460                         ( $thing : expr ) => {
1461                                 match $thing {
1462                                         Ok(a) => a,
1463                                         Err(_) => return (None, None)
1464                                 }
1465                         };
1466                 }
1467
1468                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (None, None); };
1469                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1470                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1471                 let revocation_pubkey = match self.key_storage {
1472                         Storage::Local { ref revocation_base_key, .. } => {
1473                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1474                         },
1475                         Storage::Watchtower { ref revocation_base_key, .. } => {
1476                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
1477                         },
1478                 };
1479                 let delayed_key = match self.their_delayed_payment_base_key {
1480                         None => return (None, None),
1481                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1482                 };
1483                 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
1484                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1485                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1486
1487                 let mut inputs = Vec::new();
1488                 let mut amount = 0;
1489
1490                 if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
1491                         inputs.push(TxIn {
1492                                 previous_output: BitcoinOutPoint {
1493                                         txid: htlc_txid,
1494                                         vout: 0,
1495                                 },
1496                                 script_sig: Script::new(),
1497                                 sequence: 0xfffffffd,
1498                                 witness: Vec::new(),
1499                         });
1500                         amount = tx.output[0].value;
1501                 }
1502
1503                 if !inputs.is_empty() {
1504                         let outputs = vec!(TxOut {
1505                                 script_pubkey: self.destination_script.clone(),
1506                                 value: amount, //TODO: - fee
1507                         });
1508
1509                         let mut spend_tx = Transaction {
1510                                 version: 2,
1511                                 lock_time: 0,
1512                                 input: inputs,
1513                                 output: outputs,
1514                         };
1515
1516                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1517
1518                         let sig = match self.key_storage {
1519                                 Storage::Local { ref revocation_base_key, .. } => {
1520                                         let sighash = hash_to_message!(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]);
1521                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1522                                         self.secp_ctx.sign(&sighash, &revocation_key)
1523                                 }
1524                                 Storage::Watchtower { .. } => {
1525                                         unimplemented!();
1526                                 }
1527                         };
1528                         spend_tx.input[0].witness.push(sig.serialize_der().to_vec());
1529                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1530                         spend_tx.input[0].witness.push(vec!(1));
1531                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1532
1533                         let outpoint = BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 };
1534                         let output = spend_tx.output[0].clone();
1535                         (Some(spend_tx), Some(SpendableOutputDescriptor::StaticOutput { outpoint, output }))
1536                 } else { (None, None) }
1537         }
1538
1539         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>) {
1540                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1541                 let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1542                 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1543
1544                 macro_rules! add_dynamic_output {
1545                         ($father_tx: expr, $vout: expr) => {
1546                                 if let Some(ref per_commitment_point) = *per_commitment_point {
1547                                         if let Some(ref delayed_payment_base_key) = *delayed_payment_base_key {
1548                                                 if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, per_commitment_point, delayed_payment_base_key) {
1549                                                         spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WSH {
1550                                                                 outpoint: BitcoinOutPoint { txid: $father_tx.txid(), vout: $vout },
1551                                                                 key: local_delayedkey,
1552                                                                 witness_script: chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.our_to_self_delay, &local_tx.delayed_payment_key),
1553                                                                 to_self_delay: self.our_to_self_delay,
1554                                                                 output: $father_tx.output[$vout as usize].clone(),
1555                                                         });
1556                                                 }
1557                                         }
1558                                 }
1559                         }
1560                 }
1561
1562
1563                 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
1564                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1565                 for (idx, output) in local_tx.tx.output.iter().enumerate() {
1566                         if output.script_pubkey == revokeable_p2wsh {
1567                                 add_dynamic_output!(local_tx.tx, idx as u32);
1568                                 break;
1569                         }
1570                 }
1571
1572                 for &(ref htlc, ref sigs, _) in local_tx.htlc_outputs.iter() {
1573                         if let Some(transaction_output_index) = htlc.transaction_output_index {
1574                                 if let &Some((ref their_sig, ref our_sig)) = sigs {
1575                                         if htlc.offered {
1576                                                 log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions");
1577                                                 let mut htlc_timeout_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
1578
1579                                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1580
1581                                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
1582                                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1583                                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
1584                                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1585
1586                                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1587                                                 htlc_timeout_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
1588
1589                                                 add_dynamic_output!(htlc_timeout_tx, 0);
1590                                                 res.push(htlc_timeout_tx);
1591                                         } else {
1592                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1593                                                         log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions");
1594                                                         let mut htlc_success_tx = chan_utils::build_htlc_transaction(&local_tx.txid, local_tx.feerate_per_kw, self.their_to_self_delay.unwrap(), htlc, &local_tx.delayed_payment_key, &local_tx.revocation_key);
1595
1596                                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1597
1598                                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
1599                                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1600                                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
1601                                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1602
1603                                                         htlc_success_tx.input[0].witness.push(payment_preimage.0.to_vec());
1604                                                         htlc_success_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
1605
1606                                                         add_dynamic_output!(htlc_success_tx, 0);
1607                                                         res.push(htlc_success_tx);
1608                                                 }
1609                                         }
1610                                         watch_outputs.push(local_tx.tx.output[transaction_output_index as usize].clone());
1611                                 } else { panic!("Should have sigs for non-dust local tx outputs!") }
1612                         }
1613                 }
1614
1615                 (res, spendable_outputs, watch_outputs)
1616         }
1617
1618         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1619         /// revoked using data in local_claimable_outpoints.
1620         /// Should not be used if check_spend_revoked_transaction succeeds.
1621         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
1622                 let commitment_txid = tx.txid();
1623                 // TODO: If we find a match here we need to fail back HTLCs that weren't included in the
1624                 // broadcast commitment transaction, either because they didn't meet dust or because they
1625                 // weren't yet included in our commitment transaction(s).
1626                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1627                         if local_tx.txid == commitment_txid {
1628                                 log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1629                                 match self.key_storage {
1630                                         Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
1631                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
1632                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1633                                         },
1634                                         Storage::Watchtower { .. } => {
1635                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
1636                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1637                                         }
1638                                 }
1639                         }
1640                 }
1641                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1642                         if local_tx.txid == commitment_txid {
1643                                 log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1644                                 match self.key_storage {
1645                                         Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
1646                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
1647                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1648                                         },
1649                                         Storage::Watchtower { .. } => {
1650                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
1651                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1652                                         }
1653                                 }
1654                         }
1655                 }
1656                 (Vec::new(), Vec::new(), (commitment_txid, Vec::new()))
1657         }
1658
1659         /// Generate a spendable output event when closing_transaction get registered onchain.
1660         fn check_spend_closing_transaction(&self, tx: &Transaction) -> Option<SpendableOutputDescriptor> {
1661                 if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 {
1662                         match self.key_storage {
1663                                 Storage::Local { ref shutdown_pubkey, .. } =>  {
1664                                         let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
1665                                         let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1666                                         for (idx, output) in tx.output.iter().enumerate() {
1667                                                 if shutdown_script == output.script_pubkey {
1668                                                         return Some(SpendableOutputDescriptor::StaticOutput {
1669                                                                 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: idx as u32 },
1670                                                                 output: output.clone(),
1671                                                         });
1672                                                 }
1673                                         }
1674                                 }
1675                                 Storage::Watchtower { .. } => {
1676                                         //TODO: we need to ensure an offline client will generate the event when it
1677                                         // comes back online after only the watchtower saw the transaction
1678                                 }
1679                         }
1680                 }
1681                 None
1682         }
1683
1684         /// Used by ChannelManager deserialization to broadcast the latest local state if it's copy of
1685         /// the Channel was out-of-date.
1686         pub(super) fn get_latest_local_commitment_txn(&self) -> Vec<Transaction> {
1687                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1688                         let mut res = vec![local_tx.tx.clone()];
1689                         match self.key_storage {
1690                                 Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
1691                                         res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)).0);
1692                                 },
1693                                 _ => panic!("Can only broadcast by local channelmonitor"),
1694                         };
1695                         res
1696                 } else {
1697                         Vec::new()
1698                 }
1699         }
1700
1701         fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>, Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)>) {
1702                 let mut watch_outputs = Vec::new();
1703                 let mut spendable_outputs = Vec::new();
1704                 let mut htlc_updated = Vec::new();
1705                 for tx in txn_matched {
1706                         if tx.input.len() == 1 {
1707                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1708                                 // commitment transactions and HTLC transactions will all only ever have one input,
1709                                 // which is an easy way to filter out any potential non-matching txn for lazy
1710                                 // filters.
1711                                 let prevout = &tx.input[0].previous_output;
1712                                 let mut txn: Vec<Transaction> = Vec::new();
1713                                 let funding_txo = match self.key_storage {
1714                                         Storage::Local { ref funding_info, .. } => {
1715                                                 funding_info.clone()
1716                                         }
1717                                         Storage::Watchtower { .. } => {
1718                                                 unimplemented!();
1719                                         }
1720                                 };
1721                                 if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) {
1722                                         let (remote_txn, new_outputs, mut spendable_output, mut updated) = self.check_spend_remote_transaction(tx, height);
1723                                         txn = remote_txn;
1724                                         spendable_outputs.append(&mut spendable_output);
1725                                         if !new_outputs.1.is_empty() {
1726                                                 watch_outputs.push(new_outputs);
1727                                         }
1728                                         if txn.is_empty() {
1729                                                 let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height);
1730                                                 spendable_outputs.append(&mut spendable_output);
1731                                                 txn = local_txn;
1732                                                 if !new_outputs.1.is_empty() {
1733                                                         watch_outputs.push(new_outputs);
1734                                                 }
1735                                         }
1736                                         if !funding_txo.is_none() && txn.is_empty() {
1737                                                 if let Some(spendable_output) = self.check_spend_closing_transaction(tx) {
1738                                                         spendable_outputs.push(spendable_output);
1739                                                 }
1740                                         }
1741                                         if updated.len() > 0 {
1742                                                 htlc_updated.append(&mut updated);
1743                                         }
1744                                 } else {
1745                                         if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1746                                                 let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number);
1747                                                 if let Some(tx) = tx {
1748                                                         txn.push(tx);
1749                                                 }
1750                                                 if let Some(spendable_output) = spendable_output {
1751                                                         spendable_outputs.push(spendable_output);
1752                                                 }
1753                                         }
1754                                 }
1755                                 for tx in txn.iter() {
1756                                         broadcaster.broadcast_transaction(tx);
1757                                 }
1758                         }
1759                         // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1760                         // can also be resolved in a few other ways which can have more than one output. Thus,
1761                         // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1762                         let mut updated = self.is_resolving_htlc_output(tx);
1763                         if updated.len() > 0 {
1764                                 htlc_updated.append(&mut updated);
1765                         }
1766                 }
1767                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1768                         if self.would_broadcast_at_height(height) {
1769                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1770                                 match self.key_storage {
1771                                         Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
1772                                                 let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
1773                                                 spendable_outputs.append(&mut spendable_output);
1774                                                 if !new_outputs.is_empty() {
1775                                                         watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
1776                                                 }
1777                                                 for tx in txs {
1778                                                         broadcaster.broadcast_transaction(&tx);
1779                                                 }
1780                                         },
1781                                         Storage::Watchtower { .. } => {
1782                                                 let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
1783                                                 spendable_outputs.append(&mut spendable_output);
1784                                                 if !new_outputs.is_empty() {
1785                                                         watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
1786                                                 }
1787                                                 for tx in txs {
1788                                                         broadcaster.broadcast_transaction(&tx);
1789                                                 }
1790                                         }
1791                                 }
1792                         }
1793                 }
1794                 self.last_block_hash = block_hash.clone();
1795                 (watch_outputs, spendable_outputs, htlc_updated)
1796         }
1797
1798         pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
1799                 // We need to consider all HTLCs which are:
1800                 //  * in any unrevoked remote commitment transaction, as they could broadcast said
1801                 //    transactions and we'd end up in a race, or
1802                 //  * are in our latest local commitment transaction, as this is the thing we will
1803                 //    broadcast if we go on-chain.
1804                 // Note that we consider HTLCs which were below dust threshold here - while they don't
1805                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1806                 // to the source, and if we don't fail the channel we will have to ensure that the next
1807                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1808                 // easier to just fail the channel as this case should be rare enough anyway.
1809                 macro_rules! scan_commitment {
1810                         ($htlcs: expr, $local_tx: expr) => {
1811                                 for ref htlc in $htlcs {
1812                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1813                                         // chain with enough room to claim the HTLC without our counterparty being able to
1814                                         // time out the HTLC first.
1815                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1816                                         // concern is being able to claim the corresponding inbound HTLC (on another
1817                                         // channel) before it expires. In fact, we don't even really care if our
1818                                         // counterparty here claims such an outbound HTLC after it expired as long as we
1819                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
1820                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
1821                                         // we give ourselves a few blocks of headroom after expiration before going
1822                                         // on-chain for an expired HTLC.
1823                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
1824                                         // from us until we've reached the point where we go on-chain with the
1825                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
1826                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
1827                                         //  aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
1828                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
1829                                         //      outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
1830                                         //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
1831                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
1832                                         //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
1833                                         //  The final, above, condition is checked for statically in channelmanager
1834                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
1835                                         let htlc_outbound = $local_tx == htlc.offered;
1836                                         if ( htlc_outbound && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
1837                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
1838                                                 log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
1839                                                 return true;
1840                                         }
1841                                 }
1842                         }
1843                 }
1844
1845                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1846                         scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
1847                 }
1848
1849                 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1850                         if let &Some(ref txid) = current_remote_commitment_txid {
1851                                 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
1852                                         scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1853                                 }
1854                         }
1855                         if let &Some(ref txid) = prev_remote_commitment_txid {
1856                                 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
1857                                         scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1858                                 }
1859                         }
1860                 }
1861
1862                 false
1863         }
1864
1865         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
1866         /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
1867         fn is_resolving_htlc_output(&mut self, tx: &Transaction) -> Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)> {
1868                 let mut htlc_updated = Vec::new();
1869
1870                 'outer_loop: for input in &tx.input {
1871                         let mut payment_data = None;
1872                         let revocation_sig_claim = (input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33)
1873                                 || (input.witness.len() == 3 && input.witness[2].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33);
1874                         let accepted_preimage_claim = input.witness.len() == 5 && input.witness[4].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT;
1875                         let offered_preimage_claim = input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT;
1876
1877                         macro_rules! log_claim {
1878                                 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
1879                                         // We found the output in question, but aren't failing it backwards
1880                                         // as we have no corresponding source. This implies either it is an
1881                                         // inbound HTLC or an outbound HTLC on a revoked transaction.
1882                                         let outbound_htlc = $local_tx == $htlc.offered;
1883                                         if ($local_tx && revocation_sig_claim) ||
1884                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
1885                                                 log_error!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
1886                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
1887                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
1888                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
1889                                         } else {
1890                                                 log_info!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
1891                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
1892                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
1893                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
1894                                         }
1895                                 }
1896                         }
1897
1898                         macro_rules! scan_commitment {
1899                                 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
1900                                         for (ref htlc_output, source_option) in $htlcs {
1901                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
1902                                                         if let Some(ref source) = source_option {
1903                                                                 log_claim!($tx_info, $local_tx, htlc_output, true);
1904                                                                 // We have a resolution of an HTLC either from one of our latest
1905                                                                 // local commitment transactions or an unrevoked remote commitment
1906                                                                 // transaction. This implies we either learned a preimage, the HTLC
1907                                                                 // has timed out, or we screwed up. In any case, we should now
1908                                                                 // resolve the source HTLC with the original sender.
1909                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
1910                                                         } else {
1911                                                                 log_claim!($tx_info, $local_tx, htlc_output, false);
1912                                                                 continue 'outer_loop;
1913                                                         }
1914                                                 }
1915                                         }
1916                                 }
1917                         }
1918
1919                         if let Some(ref current_local_signed_commitment_tx) = self.current_local_signed_commitment_tx {
1920                                 if input.previous_output.txid == current_local_signed_commitment_tx.txid {
1921                                         scan_commitment!(current_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
1922                                                 "our latest local commitment tx", true);
1923                                 }
1924                         }
1925                         if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
1926                                 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
1927                                         scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
1928                                                 "our previous local commitment tx", true);
1929                                 }
1930                         }
1931                         if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
1932                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
1933                                         "remote commitment tx", false);
1934                         }
1935
1936                         // Check that scan_commitment, above, decided there is some source worth relaying an
1937                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
1938                         if let Some((source, payment_hash)) = payment_data {
1939                                 let mut payment_preimage = PaymentPreimage([0; 32]);
1940                                 if accepted_preimage_claim {
1941                                         payment_preimage.0.copy_from_slice(&input.witness[3]);
1942                                         htlc_updated.push((source, Some(payment_preimage), payment_hash));
1943                                 } else if offered_preimage_claim {
1944                                         payment_preimage.0.copy_from_slice(&input.witness[1]);
1945                                         htlc_updated.push((source, Some(payment_preimage), payment_hash));
1946                                 } else {
1947                                         htlc_updated.push((source, None, payment_hash));
1948                                 }
1949                         }
1950                 }
1951                 htlc_updated
1952         }
1953 }
1954
1955 const MAX_ALLOC_SIZE: usize = 64*1024;
1956
1957 impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelMonitor) {
1958         fn read(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
1959                 let secp_ctx = Secp256k1::new();
1960                 macro_rules! unwrap_obj {
1961                         ($key: expr) => {
1962                                 match $key {
1963                                         Ok(res) => res,
1964                                         Err(_) => return Err(DecodeError::InvalidValue),
1965                                 }
1966                         }
1967                 }
1968
1969                 let _ver: u8 = Readable::read(reader)?;
1970                 let min_ver: u8 = Readable::read(reader)?;
1971                 if min_ver > SERIALIZATION_VERSION {
1972                         return Err(DecodeError::UnknownVersion);
1973                 }
1974
1975                 let commitment_transaction_number_obscure_factor = <U48 as Readable<R>>::read(reader)?.0;
1976
1977                 let key_storage = match <u8 as Readable<R>>::read(reader)? {
1978                         0 => {
1979                                 let revocation_base_key = Readable::read(reader)?;
1980                                 let htlc_base_key = Readable::read(reader)?;
1981                                 let delayed_payment_base_key = Readable::read(reader)?;
1982                                 let payment_base_key = Readable::read(reader)?;
1983                                 let shutdown_pubkey = Readable::read(reader)?;
1984                                 let prev_latest_per_commitment_point = Readable::read(reader)?;
1985                                 let latest_per_commitment_point = Readable::read(reader)?;
1986                                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
1987                                 // barely-init'd ChannelMonitors that we can't do anything with.
1988                                 let outpoint = OutPoint {
1989                                         txid: Readable::read(reader)?,
1990                                         index: Readable::read(reader)?,
1991                                 };
1992                                 let funding_info = Some((outpoint, Readable::read(reader)?));
1993                                 let current_remote_commitment_txid = Readable::read(reader)?;
1994                                 let prev_remote_commitment_txid = Readable::read(reader)?;
1995                                 Storage::Local {
1996                                         revocation_base_key,
1997                                         htlc_base_key,
1998                                         delayed_payment_base_key,
1999                                         payment_base_key,
2000                                         shutdown_pubkey,
2001                                         prev_latest_per_commitment_point,
2002                                         latest_per_commitment_point,
2003                                         funding_info,
2004                                         current_remote_commitment_txid,
2005                                         prev_remote_commitment_txid,
2006                                 }
2007                         },
2008                         _ => return Err(DecodeError::InvalidValue),
2009                 };
2010
2011                 let their_htlc_base_key = Some(Readable::read(reader)?);
2012                 let their_delayed_payment_base_key = Some(Readable::read(reader)?);
2013
2014                 let their_cur_revocation_points = {
2015                         let first_idx = <U48 as Readable<R>>::read(reader)?.0;
2016                         if first_idx == 0 {
2017                                 None
2018                         } else {
2019                                 let first_point = Readable::read(reader)?;
2020                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2021                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2022                                         Some((first_idx, first_point, None))
2023                                 } else {
2024                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2025                                 }
2026                         }
2027                 };
2028
2029                 let our_to_self_delay: u16 = Readable::read(reader)?;
2030                 let their_to_self_delay: Option<u16> = Some(Readable::read(reader)?);
2031
2032                 let mut old_secrets = [([0; 32], 1 << 48); 49];
2033                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
2034                         *secret = Readable::read(reader)?;
2035                         *idx = Readable::read(reader)?;
2036                 }
2037
2038                 macro_rules! read_htlc_in_commitment {
2039                         () => {
2040                                 {
2041                                         let offered: bool = Readable::read(reader)?;
2042                                         let amount_msat: u64 = Readable::read(reader)?;
2043                                         let cltv_expiry: u32 = Readable::read(reader)?;
2044                                         let payment_hash: PaymentHash = Readable::read(reader)?;
2045                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
2046
2047                                         HTLCOutputInCommitment {
2048                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2049                                         }
2050                                 }
2051                         }
2052                 }
2053
2054                 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2055                 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2056                 for _ in 0..remote_claimable_outpoints_len {
2057                         let txid: Sha256dHash = Readable::read(reader)?;
2058                         let htlcs_count: u64 = Readable::read(reader)?;
2059                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2060                         for _ in 0..htlcs_count {
2061                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable<R>>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2062                         }
2063                         if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2064                                 return Err(DecodeError::InvalidValue);
2065                         }
2066                 }
2067
2068                 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2069                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2070                 for _ in 0..remote_commitment_txn_on_chain_len {
2071                         let txid: Sha256dHash = Readable::read(reader)?;
2072                         let commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2073                         let outputs_count = <u64 as Readable<R>>::read(reader)?;
2074                         let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2075                         for _ in 0..outputs_count {
2076                                 outputs.push(Readable::read(reader)?);
2077                         }
2078                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2079                                 return Err(DecodeError::InvalidValue);
2080                         }
2081                 }
2082
2083                 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2084                 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2085                 for _ in 0..remote_hash_commitment_number_len {
2086                         let payment_hash: PaymentHash = Readable::read(reader)?;
2087                         let commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2088                         if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2089                                 return Err(DecodeError::InvalidValue);
2090                         }
2091                 }
2092
2093                 macro_rules! read_local_tx {
2094                         () => {
2095                                 {
2096                                         let tx = match Transaction::consensus_decode(reader.by_ref()) {
2097                                                 Ok(tx) => tx,
2098                                                 Err(e) => match e {
2099                                                         encode::Error::Io(ioe) => return Err(DecodeError::Io(ioe)),
2100                                                         _ => return Err(DecodeError::InvalidValue),
2101                                                 },
2102                                         };
2103
2104                                         if tx.input.is_empty() {
2105                                                 // Ensure tx didn't hit the 0-input ambiguity case.
2106                                                 return Err(DecodeError::InvalidValue);
2107                                         }
2108
2109                                         let revocation_key = Readable::read(reader)?;
2110                                         let a_htlc_key = Readable::read(reader)?;
2111                                         let b_htlc_key = Readable::read(reader)?;
2112                                         let delayed_payment_key = Readable::read(reader)?;
2113                                         let feerate_per_kw: u64 = Readable::read(reader)?;
2114
2115                                         let htlcs_len: u64 = Readable::read(reader)?;
2116                                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2117                                         for _ in 0..htlcs_len {
2118                                                 let htlc = read_htlc_in_commitment!();
2119                                                 let sigs = match <u8 as Readable<R>>::read(reader)? {
2120                                                         0 => None,
2121                                                         1 => Some((Readable::read(reader)?, Readable::read(reader)?)),
2122                                                         _ => return Err(DecodeError::InvalidValue),
2123                                                 };
2124                                                 htlcs.push((htlc, sigs, Readable::read(reader)?));
2125                                         }
2126
2127                                         LocalSignedTx {
2128                                                 txid: tx.txid(),
2129                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw,
2130                                                 htlc_outputs: htlcs
2131                                         }
2132                                 }
2133                         }
2134                 }
2135
2136                 let prev_local_signed_commitment_tx = match <u8 as Readable<R>>::read(reader)? {
2137                         0 => None,
2138                         1 => {
2139                                 Some(read_local_tx!())
2140                         },
2141                         _ => return Err(DecodeError::InvalidValue),
2142                 };
2143
2144                 let current_local_signed_commitment_tx = match <u8 as Readable<R>>::read(reader)? {
2145                         0 => None,
2146                         1 => {
2147                                 Some(read_local_tx!())
2148                         },
2149                         _ => return Err(DecodeError::InvalidValue),
2150                 };
2151
2152                 let current_remote_commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2153
2154                 let payment_preimages_len: u64 = Readable::read(reader)?;
2155                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2156                 for _ in 0..payment_preimages_len {
2157                         let preimage: PaymentPreimage = Readable::read(reader)?;
2158                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2159                         if let Some(_) = payment_preimages.insert(hash, preimage) {
2160                                 return Err(DecodeError::InvalidValue);
2161                         }
2162                 }
2163
2164                 let last_block_hash: Sha256dHash = Readable::read(reader)?;
2165                 let destination_script = Readable::read(reader)?;
2166
2167                 Ok((last_block_hash.clone(), ChannelMonitor {
2168                         commitment_transaction_number_obscure_factor,
2169
2170                         key_storage,
2171                         their_htlc_base_key,
2172                         their_delayed_payment_base_key,
2173                         their_cur_revocation_points,
2174
2175                         our_to_self_delay,
2176                         their_to_self_delay,
2177
2178                         old_secrets,
2179                         remote_claimable_outpoints,
2180                         remote_commitment_txn_on_chain,
2181                         remote_hash_commitment_number,
2182
2183                         prev_local_signed_commitment_tx,
2184                         current_local_signed_commitment_tx,
2185                         current_remote_commitment_number,
2186
2187                         payment_preimages,
2188
2189                         destination_script,
2190                         last_block_hash,
2191                         secp_ctx,
2192                         logger,
2193                 }))
2194         }
2195
2196 }
2197
2198 #[cfg(test)]
2199 mod tests {
2200         use bitcoin::blockdata::script::Script;
2201         use bitcoin::blockdata::transaction::Transaction;
2202         use bitcoin_hashes::Hash;
2203         use bitcoin_hashes::sha256::Hash as Sha256;
2204         use hex;
2205         use ln::channelmanager::{PaymentPreimage, PaymentHash};
2206         use ln::channelmonitor::ChannelMonitor;
2207         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
2208         use util::test_utils::TestLogger;
2209         use secp256k1::key::{SecretKey,PublicKey};
2210         use secp256k1::Secp256k1;
2211         use rand::{thread_rng,Rng};
2212         use std::sync::Arc;
2213
2214         #[test]
2215         fn test_per_commitment_storage() {
2216                 // Test vectors from BOLT 3:
2217                 let mut secrets: Vec<[u8; 32]> = Vec::new();
2218                 let mut monitor: ChannelMonitor;
2219                 let secp_ctx = Secp256k1::new();
2220                 let logger = Arc::new(TestLogger::new());
2221
2222                 macro_rules! test_secrets {
2223                         () => {
2224                                 let mut idx = 281474976710655;
2225                                 for secret in secrets.iter() {
2226                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
2227                                         idx -= 1;
2228                                 }
2229                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
2230                                 assert!(monitor.get_secret(idx).is_none());
2231                         };
2232                 }
2233
2234                 {
2235                         // insert_secret correct sequence
2236                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2237                         secrets.clear();
2238
2239                         secrets.push([0; 32]);
2240                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2241                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2242                         test_secrets!();
2243
2244                         secrets.push([0; 32]);
2245                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2246                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2247                         test_secrets!();
2248
2249                         secrets.push([0; 32]);
2250                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2251                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2252                         test_secrets!();
2253
2254                         secrets.push([0; 32]);
2255                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2256                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2257                         test_secrets!();
2258
2259                         secrets.push([0; 32]);
2260                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2261                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2262                         test_secrets!();
2263
2264                         secrets.push([0; 32]);
2265                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2266                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2267                         test_secrets!();
2268
2269                         secrets.push([0; 32]);
2270                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2271                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2272                         test_secrets!();
2273
2274                         secrets.push([0; 32]);
2275                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2276                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
2277                         test_secrets!();
2278                 }
2279
2280                 {
2281                         // insert_secret #1 incorrect
2282                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2283                         secrets.clear();
2284
2285                         secrets.push([0; 32]);
2286                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2287                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2288                         test_secrets!();
2289
2290                         secrets.push([0; 32]);
2291                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2292                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap_err().0,
2293                                         "Previous secret did not match new one");
2294                 }
2295
2296                 {
2297                         // insert_secret #2 incorrect (#1 derived from incorrect)
2298                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2299                         secrets.clear();
2300
2301                         secrets.push([0; 32]);
2302                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2303                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2304                         test_secrets!();
2305
2306                         secrets.push([0; 32]);
2307                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2308                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2309                         test_secrets!();
2310
2311                         secrets.push([0; 32]);
2312                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2313                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2314                         test_secrets!();
2315
2316                         secrets.push([0; 32]);
2317                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2318                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
2319                                         "Previous secret did not match new one");
2320                 }
2321
2322                 {
2323                         // insert_secret #3 incorrect
2324                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2325                         secrets.clear();
2326
2327                         secrets.push([0; 32]);
2328                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2329                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2330                         test_secrets!();
2331
2332                         secrets.push([0; 32]);
2333                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2334                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2335                         test_secrets!();
2336
2337                         secrets.push([0; 32]);
2338                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2339                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2340                         test_secrets!();
2341
2342                         secrets.push([0; 32]);
2343                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2344                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
2345                                         "Previous secret did not match new one");
2346                 }
2347
2348                 {
2349                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
2350                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2351                         secrets.clear();
2352
2353                         secrets.push([0; 32]);
2354                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2355                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2356                         test_secrets!();
2357
2358                         secrets.push([0; 32]);
2359                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2360                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2361                         test_secrets!();
2362
2363                         secrets.push([0; 32]);
2364                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2365                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2366                         test_secrets!();
2367
2368                         secrets.push([0; 32]);
2369                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
2370                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2371                         test_secrets!();
2372
2373                         secrets.push([0; 32]);
2374                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2375                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2376                         test_secrets!();
2377
2378                         secrets.push([0; 32]);
2379                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2380                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2381                         test_secrets!();
2382
2383                         secrets.push([0; 32]);
2384                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2385                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2386                         test_secrets!();
2387
2388                         secrets.push([0; 32]);
2389                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2390                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2391                                         "Previous secret did not match new one");
2392                 }
2393
2394                 {
2395                         // insert_secret #5 incorrect
2396                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2397                         secrets.clear();
2398
2399                         secrets.push([0; 32]);
2400                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2401                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2402                         test_secrets!();
2403
2404                         secrets.push([0; 32]);
2405                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2406                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2407                         test_secrets!();
2408
2409                         secrets.push([0; 32]);
2410                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2411                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2412                         test_secrets!();
2413
2414                         secrets.push([0; 32]);
2415                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2416                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2417                         test_secrets!();
2418
2419                         secrets.push([0; 32]);
2420                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2421                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2422                         test_secrets!();
2423
2424                         secrets.push([0; 32]);
2425                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2426                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap_err().0,
2427                                         "Previous secret did not match new one");
2428                 }
2429
2430                 {
2431                         // insert_secret #6 incorrect (5 derived from incorrect)
2432                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2433                         secrets.clear();
2434
2435                         secrets.push([0; 32]);
2436                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2437                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2438                         test_secrets!();
2439
2440                         secrets.push([0; 32]);
2441                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2442                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2443                         test_secrets!();
2444
2445                         secrets.push([0; 32]);
2446                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2447                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2448                         test_secrets!();
2449
2450                         secrets.push([0; 32]);
2451                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2452                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2453                         test_secrets!();
2454
2455                         secrets.push([0; 32]);
2456                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2457                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2458                         test_secrets!();
2459
2460                         secrets.push([0; 32]);
2461                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
2462                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2463                         test_secrets!();
2464
2465                         secrets.push([0; 32]);
2466                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2467                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2468                         test_secrets!();
2469
2470                         secrets.push([0; 32]);
2471                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2472                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2473                                         "Previous secret did not match new one");
2474                 }
2475
2476                 {
2477                         // insert_secret #7 incorrect
2478                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2479                         secrets.clear();
2480
2481                         secrets.push([0; 32]);
2482                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2483                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2484                         test_secrets!();
2485
2486                         secrets.push([0; 32]);
2487                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2488                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2489                         test_secrets!();
2490
2491                         secrets.push([0; 32]);
2492                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2493                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2494                         test_secrets!();
2495
2496                         secrets.push([0; 32]);
2497                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2498                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2499                         test_secrets!();
2500
2501                         secrets.push([0; 32]);
2502                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2503                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2504                         test_secrets!();
2505
2506                         secrets.push([0; 32]);
2507                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2508                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2509                         test_secrets!();
2510
2511                         secrets.push([0; 32]);
2512                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
2513                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2514                         test_secrets!();
2515
2516                         secrets.push([0; 32]);
2517                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2518                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2519                                         "Previous secret did not match new one");
2520                 }
2521
2522                 {
2523                         // insert_secret #8 incorrect
2524                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2525                         secrets.clear();
2526
2527                         secrets.push([0; 32]);
2528                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2529                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2530                         test_secrets!();
2531
2532                         secrets.push([0; 32]);
2533                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2534                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2535                         test_secrets!();
2536
2537                         secrets.push([0; 32]);
2538                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2539                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2540                         test_secrets!();
2541
2542                         secrets.push([0; 32]);
2543                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2544                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2545                         test_secrets!();
2546
2547                         secrets.push([0; 32]);
2548                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2549                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2550                         test_secrets!();
2551
2552                         secrets.push([0; 32]);
2553                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2554                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2555                         test_secrets!();
2556
2557                         secrets.push([0; 32]);
2558                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2559                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2560                         test_secrets!();
2561
2562                         secrets.push([0; 32]);
2563                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
2564                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2565                                         "Previous secret did not match new one");
2566                 }
2567         }
2568
2569         #[test]
2570         fn test_prune_preimages() {
2571                 let secp_ctx = Secp256k1::new();
2572                 let logger = Arc::new(TestLogger::new());
2573
2574                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2575                 macro_rules! dummy_keys {
2576                         () => {
2577                                 {
2578                                         TxCreationKeys {
2579                                                 per_commitment_point: dummy_key.clone(),
2580                                                 revocation_key: dummy_key.clone(),
2581                                                 a_htlc_key: dummy_key.clone(),
2582                                                 b_htlc_key: dummy_key.clone(),
2583                                                 a_delayed_payment_key: dummy_key.clone(),
2584                                                 b_payment_key: dummy_key.clone(),
2585                                         }
2586                                 }
2587                         }
2588                 }
2589                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2590
2591                 let mut preimages = Vec::new();
2592                 {
2593                         let mut rng  = thread_rng();
2594                         for _ in 0..20 {
2595                                 let mut preimage = PaymentPreimage([0; 32]);
2596                                 rng.fill_bytes(&mut preimage.0[..]);
2597                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2598                                 preimages.push((preimage, hash));
2599                         }
2600                 }
2601
2602                 macro_rules! preimages_slice_to_htlc_outputs {
2603                         ($preimages_slice: expr) => {
2604                                 {
2605                                         let mut res = Vec::new();
2606                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
2607                                                 res.push((HTLCOutputInCommitment {
2608                                                         offered: true,
2609                                                         amount_msat: 0,
2610                                                         cltv_expiry: 0,
2611                                                         payment_hash: preimage.1.clone(),
2612                                                         transaction_output_index: Some(idx as u32),
2613                                                 }, None));
2614                                         }
2615                                         res
2616                                 }
2617                         }
2618                 }
2619                 macro_rules! preimages_to_local_htlcs {
2620                         ($preimages_slice: expr) => {
2621                                 {
2622                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2623                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2624                                         res
2625                                 }
2626                         }
2627                 }
2628
2629                 macro_rules! test_preimages_exist {
2630                         ($preimages_slice: expr, $monitor: expr) => {
2631                                 for preimage in $preimages_slice {
2632                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
2633                                 }
2634                         }
2635                 }
2636
2637                 // Prune with one old state and a local commitment tx holding a few overlaps with the
2638                 // old state.
2639                 let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2640                 monitor.set_their_to_self_delay(10);
2641
2642                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
2643                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
2644                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
2645                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
2646                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key);
2647                 for &(ref preimage, ref hash) in preimages.iter() {
2648                         monitor.provide_payment_preimage(hash, preimage);
2649                 }
2650
2651                 // Now provide a secret, pruning preimages 10-15
2652                 let mut secret = [0; 32];
2653                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2654                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2655                 assert_eq!(monitor.payment_preimages.len(), 15);
2656                 test_preimages_exist!(&preimages[0..10], monitor);
2657                 test_preimages_exist!(&preimages[15..20], monitor);
2658
2659                 // Now provide a further secret, pruning preimages 15-17
2660                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2661                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2662                 assert_eq!(monitor.payment_preimages.len(), 13);
2663                 test_preimages_exist!(&preimages[0..10], monitor);
2664                 test_preimages_exist!(&preimages[17..20], monitor);
2665
2666                 // Now update local commitment tx info, pruning only element 18 as we still care about the
2667                 // previous commitment tx's preimages too
2668                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
2669                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2670                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2671                 assert_eq!(monitor.payment_preimages.len(), 12);
2672                 test_preimages_exist!(&preimages[0..10], monitor);
2673                 test_preimages_exist!(&preimages[18..20], monitor);
2674
2675                 // But if we do it again, we'll prune 5-10
2676                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
2677                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2678                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2679                 assert_eq!(monitor.payment_preimages.len(), 5);
2680                 test_preimages_exist!(&preimages[0..5], monitor);
2681         }
2682
2683         // Further testing is done in the ChannelManager integration tests.
2684 }