_ Git - rust-lightning/blob - src/ln/channelmonitor.rs

   1 use bitcoin::blockdata::block::BlockHeader;
   2 use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction};
   3 use bitcoin::blockdata::script::Script;
   4 use bitcoin::network::serialize;
   5 use bitcoin::util::hash::Sha256dHash;
   6 use bitcoin::util::bip143;
   7
   8 use crypto::digest::Digest;
   9
  10 use secp256k1::{Secp256k1,Message,Signature};
  11 use secp256k1::key::{SecretKey,PublicKey};
  12
  13 use ln::msgs::HandleError;
  14 use ln::chan_utils;
  15 use ln::chan_utils::HTLCOutputInCommitment;
  16 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
  17 use chain::transaction::OutPoint;
  18 use util::sha2::Sha256;
  19 use util::byte_utils;
  20
  21 use std::collections::HashMap;
  22 use std::sync::{Arc,Mutex};
  23 use std::{hash,cmp};
  24
  25 pub enum ChannelMonitorUpdateErr {
  26         /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
  27         /// to succeed at some point in the future).
  28         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  29         /// submitting new commitment transactions to the remote party.
  30         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  31         /// the channel to an operational state.
  32         TemporaryFailure,
  33         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  34         /// different watchtower and cannot update with all watchtowers that were previously informed
  35         /// of this channel). This will force-close the channel in question.
  36         PermanentFailure,
  37 }
  38
  39 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
  40 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
  41 /// events to it, while also taking any add_update_monitor events and passing them to some remote
  42 /// server(s).
  43 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
  44 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
  45 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
  46 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
  47 pub trait ManyChannelMonitor: Send + Sync {
  48         /// Adds or updates a monitor for the given `funding_txo`.
  49         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
  50 }
  51
  52 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
  53 /// watchtower or watch our own channels.
  54 /// Note that you must provide your own key by which to refer to channels.
  55 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
  56 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
  57 /// index by a PublicKey which is required to sign any updates.
  58 /// If you're using this for local monitoring of your own channels, you probably want to use
  59 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
  60 pub struct SimpleManyChannelMonitor<Key> {
  61         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  62         chain_monitor: Arc<ChainWatchInterface>,
  63         broadcaster: Arc<BroadcasterInterface>
  64 }
  65
  66 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
  67         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
  68                 let monitors = self.monitors.lock().unwrap();
  69                 for monitor in monitors.values() {
  70                         monitor.block_connected(txn_matched, height, &*self.broadcaster);
  71                 }
  72         }
  73
  74         fn block_disconnected(&self, _: &BlockHeader) { }
  75 }
  76
  77 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
  78         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
  79                 let res = Arc::new(SimpleManyChannelMonitor {
  80                         monitors: Mutex::new(HashMap::new()),
  81                         chain_monitor,
  82                         broadcaster
  83                 });
  84                 let weak_res = Arc::downgrade(&res);
  85                 res.chain_monitor.register_listener(weak_res);
  86                 res
  87         }
  88
  89         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
  90                 let mut monitors = self.monitors.lock().unwrap();
  91                 match monitors.get_mut(&key) {
  92                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
  93                         None => {}
  94                 };
  95                 match monitor.funding_txo {
  96                         None => self.chain_monitor.watch_all_txn(),
  97                         Some(outpoint) => self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32)),
  98                 }
  99                 monitors.insert(key, monitor);
 100                 Ok(())
 101         }
 102 }
 103
 104 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 105         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 106                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 107                         Ok(_) => Ok(()),
 108                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 109                 }
 110         }
 111 }
 112
 113 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 114 /// instead claiming it in its own individual transaction.
 115 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 116 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 117 /// HTLC-Success transaction.
 118 const CLTV_CLAIM_BUFFER: u32 = 6;
 119
 120 #[derive(Clone, PartialEq)]
 121 enum KeyStorage {
 122         PrivMode {
 123                 revocation_base_key: SecretKey,
 124                 htlc_base_key: SecretKey,
 125         },
 126         SigsMode {
 127                 revocation_base_key: PublicKey,
 128                 htlc_base_key: PublicKey,
 129                 sigs: HashMap<Sha256dHash, Signature>,
 130         }
 131 }
 132
 133 #[derive(Clone, PartialEq)]
 134 struct LocalSignedTx {
 135         /// txid of the transaction in tx, just used to make comparison faster
 136         txid: Sha256dHash,
 137         tx: Transaction,
 138         revocation_key: PublicKey,
 139         a_htlc_key: PublicKey,
 140         b_htlc_key: PublicKey,
 141         delayed_payment_key: PublicKey,
 142         feerate_per_kw: u64,
 143         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 144 }
 145
 146 const SERIALIZATION_VERSION: u8 = 1;
 147 const MIN_SERIALIZATION_VERSION: u8 = 1;
 148
 149 pub struct ChannelMonitor {
 150         funding_txo: Option<OutPoint>,
 151         commitment_transaction_number_obscure_factor: u64,
 152
 153         key_storage: KeyStorage,
 154         delayed_payment_base_key: PublicKey,
 155         their_htlc_base_key: Option<PublicKey>,
 156         // first is the idx of the first of the two revocation points
 157         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 158
 159         our_to_self_delay: u16,
 160         their_to_self_delay: Option<u16>,
 161
 162         old_secrets: [([u8; 32], u64); 49],
 163         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 164         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 165         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 166         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 167         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 168         /// can be used to derive the revocation key and claim the transactions.
 169         remote_commitment_txn_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 170         /// Cache used to make pruning of payment_preimages faster.
 171         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 172         /// remote transactions (ie should remain pretty small).
 173         /// Serialized to disk but should generally not be sent to Watchtowers.
 174         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 175
 176         // We store two local commitment transactions to avoid any race conditions where we may update
 177         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 178         // various monitors for one channel being out of sync, and us broadcasting a local
 179         // transaction for which we have deleted claim information on some watchtowers.
 180         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 181         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 182
 183         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 184
 185         destination_script: Script,
 186         secp_ctx: Secp256k1, //TODO: dedup this a bit...
 187 }
 188 impl Clone for ChannelMonitor {
 189         fn clone(&self) -> Self {
 190                 ChannelMonitor {
 191                         funding_txo: self.funding_txo.clone(),
 192                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 193
 194                         key_storage: self.key_storage.clone(),
 195                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 196                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 197                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 198
 199                         our_to_self_delay: self.our_to_self_delay,
 200                         their_to_self_delay: self.their_to_self_delay,
 201
 202                         old_secrets: self.old_secrets.clone(),
 203                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 204                         remote_commitment_txn_on_chain: Mutex::new((*self.remote_commitment_txn_on_chain.lock().unwrap()).clone()),
 205                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 206
 207                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 208                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 209
 210                         payment_preimages: self.payment_preimages.clone(),
 211
 212                         destination_script: self.destination_script.clone(),
 213                         secp_ctx: self.secp_ctx.clone(),
 214                 }
 215         }
 216 }
 217
 218 #[cfg(any(test, feature = "fuzztarget"))]
 219 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 220 /// underlying object
 221 impl PartialEq for ChannelMonitor {
 222         fn eq(&self, other: &Self) -> bool {
 223                 if self.funding_txo != other.funding_txo ||
 224                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 225                         self.key_storage != other.key_storage ||
 226                         self.delayed_payment_base_key != other.delayed_payment_base_key ||
 227                         self.their_htlc_base_key != other.their_htlc_base_key ||
 228                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 229                         self.our_to_self_delay != other.our_to_self_delay ||
 230                         self.their_to_self_delay != other.their_to_self_delay ||
 231                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 232                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 233                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 234                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 235                         self.payment_preimages != other.payment_preimages ||
 236                         self.destination_script != other.destination_script
 237                 {
 238                         false
 239                 } else {
 240                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 241                                 if secret != o_secret || idx != o_idx {
 242                                         return false
 243                                 }
 244                         }
 245                         let us = self.remote_commitment_txn_on_chain.lock().unwrap();
 246                         let them = other.remote_commitment_txn_on_chain.lock().unwrap();
 247                         *us == *them
 248                 }
 249         }
 250 }
 251
 252 impl ChannelMonitor {
 253         pub fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
 254                 ChannelMonitor {
 255                         funding_txo: None,
 256                         commitment_transaction_number_obscure_factor: 0,
 257
 258                         key_storage: KeyStorage::PrivMode {
 259                                 revocation_base_key: revocation_base_key.clone(),
 260                                 htlc_base_key: htlc_base_key.clone(),
 261                         },
 262                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 263                         their_htlc_base_key: None,
 264                         their_cur_revocation_points: None,
 265
 266                         our_to_self_delay: our_to_self_delay,
 267                         their_to_self_delay: None,
 268
 269                         old_secrets: [([0; 32], 1 << 48); 49],
 270                         remote_claimable_outpoints: HashMap::new(),
 271                         remote_commitment_txn_on_chain: Mutex::new(HashMap::new()),
 272                         remote_hash_commitment_number: HashMap::new(),
 273
 274                         prev_local_signed_commitment_tx: None,
 275                         current_local_signed_commitment_tx: None,
 276
 277                         payment_preimages: HashMap::new(),
 278
 279                         destination_script: destination_script,
 280                         secp_ctx: Secp256k1::new(),
 281                 }
 282         }
 283
 284         #[inline]
 285         fn place_secret(idx: u64) -> u8 {
 286                 for i in 0..48 {
 287                         if idx & (1 << i) == (1 << i) {
 288                                 return i
 289                         }
 290                 }
 291                 48
 292         }
 293
 294         #[inline]
 295         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 296                 let mut res: [u8; 32] = secret;
 297                 for i in 0..bits {
 298                         let bitpos = bits - 1 - i;
 299                         if idx & (1 << bitpos) == (1 << bitpos) {
 300                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 301                                 let mut sha = Sha256::new();
 302                                 sha.input(&res);
 303                                 sha.result(&mut res);
 304                         }
 305                 }
 306                 res
 307         }
 308
 309         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 310         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 311         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 312         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 313         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 314         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 315                 let pos = ChannelMonitor::place_secret(idx);
 316                 for i in 0..pos {
 317                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 318                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 319                                 return Err(HandleError{err: "Previous secret did not match new one", msg: None})
 320                         }
 321                 }
 322                 self.old_secrets[pos as usize] = (secret, idx);
 323
 324                 if let Some(new_revocation_point) = their_next_revocation_point {
 325                         match self.their_cur_revocation_points {
 326                                 Some(old_points) => {
 327                                         if old_points.0 == new_revocation_point.0 + 1 {
 328                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 329                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 330                                                 if let Some(old_second_point) = old_points.2 {
 331                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 332                                                 } else {
 333                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 334                                                 }
 335                                         } else {
 336                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 337                                         }
 338                                 },
 339                                 None => {
 340                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 341                                 }
 342                         }
 343                 }
 344
 345                 if !self.payment_preimages.is_empty() {
 346                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 347                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 348                         let min_idx = self.get_min_seen_secret();
 349                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 350
 351                         self.payment_preimages.retain(|&k, _| {
 352                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 353                                         if k == htlc.payment_hash {
 354                                                 return true
 355                                         }
 356                                 }
 357                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 358                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 359                                                 if k == htlc.payment_hash {
 360                                                         return true
 361                                                 }
 362                                         }
 363                                 }
 364                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 365                                         if *cn < min_idx {
 366                                                 return true
 367                                         }
 368                                         true
 369                                 } else { false };
 370                                 if contains {
 371                                         remote_hash_commitment_number.remove(&k);
 372                                 }
 373                                 false
 374                         });
 375                 }
 376
 377                 Ok(())
 378         }
 379
 380         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 381         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 382         /// possibly future revocation/preimage information) to claim outputs where possible.
 383         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 384         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 385                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 386                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 387                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 388                 // timeouts)
 389                 for htlc in &htlc_outputs {
 390                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 391                 }
 392                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 393         }
 394
 395         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 396         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 397         /// is important that any clones of this channel monitor (including remote clones) by kept
 398         /// up-to-date as our local commitment transaction is updated.
 399         /// Panics if set_their_to_self_delay has never been called.
 400         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, Signature, Signature)>) {
 401                 assert!(self.their_to_self_delay.is_some());
 402                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 403                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 404                         txid: signed_commitment_tx.txid(),
 405                         tx: signed_commitment_tx,
 406                         revocation_key: local_keys.revocation_key,
 407                         a_htlc_key: local_keys.a_htlc_key,
 408                         b_htlc_key: local_keys.b_htlc_key,
 409                         delayed_payment_key: local_keys.a_delayed_payment_key,
 410                         feerate_per_kw,
 411                         htlc_outputs,
 412                 });
 413         }
 414
 415         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 416         /// commitment_tx_infos which contain the payment hash have been revoked.
 417         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 418                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 419         }
 420
 421         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 422                 match self.funding_txo {
 423                         Some(txo) => if other.funding_txo.is_some() && other.funding_txo.unwrap() != txo {
 424                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", msg: None});
 425                         },
 426                         None => if other.funding_txo.is_some() {
 427                                 self.funding_txo = other.funding_txo;
 428                         }
 429                 }
 430                 let other_min_secret = other.get_min_seen_secret();
 431                 let our_min_secret = self.get_min_seen_secret();
 432                 if our_min_secret > other_min_secret {
 433                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 434                 }
 435                 if our_min_secret >= other_min_secret {
 436                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 437                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 438                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 439                         }
 440                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 441                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 442                         }
 443                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 444                                 self.current_local_signed_commitment_tx = Some(local_tx);
 445                         }
 446                         self.payment_preimages = other.payment_preimages;
 447                 }
 448                 Ok(())
 449         }
 450
 451         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 452         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 453                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 454                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 455         }
 456
 457         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 458         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 459         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 460         /// provides slightly better privacy.
 461         pub(super) fn set_funding_info(&mut self, funding_info: OutPoint) {
 462                 self.funding_txo = Some(funding_info);
 463         }
 464
 465         pub(super) fn set_their_htlc_base_key(&mut self, their_htlc_base_key: &PublicKey) {
 466                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 467         }
 468
 469         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 470                 self.their_to_self_delay = Some(their_to_self_delay);
 471         }
 472
 473         pub(super) fn unset_funding_info(&mut self) {
 474                 self.funding_txo = None;
 475         }
 476
 477         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 478                 self.funding_txo
 479         }
 480
 481         /// Serializes into a vec, with various modes for the exposed pub fns
 482         fn serialize(&self, for_local_storage: bool) -> Vec<u8> {
 483                 let mut res = Vec::new();
 484                 res.push(SERIALIZATION_VERSION);
 485                 res.push(MIN_SERIALIZATION_VERSION);
 486
 487                 match self.funding_txo {
 488                         Some(outpoint) => {
 489                                 res.extend_from_slice(&outpoint.txid[..]);
 490                                 res.extend_from_slice(&byte_utils::be16_to_array(outpoint.index));
 491                         },
 492                         None => {
 493                                 // We haven't even been initialized...not sure why anyone is serializing us, but
 494                                 // not much to give them.
 495                                 return res;
 496                         },
 497                 }
 498
 499                 // Set in initial Channel-object creation, so should always be set by now:
 500                 res.extend_from_slice(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor));
 501
 502                 match self.key_storage {
 503                         KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 504                                 res.push(0);
 505                                 res.extend_from_slice(&revocation_base_key[..]);
 506                                 res.extend_from_slice(&htlc_base_key[..]);
 507                         },
 508                         KeyStorage::SigsMode { .. } => unimplemented!(),
 509                 }
 510
 511                 res.extend_from_slice(&self.delayed_payment_base_key.serialize());
 512                 res.extend_from_slice(&self.their_htlc_base_key.as_ref().unwrap().serialize());
 513
 514                 match self.their_cur_revocation_points {
 515                         Some((idx, pubkey, second_option)) => {
 516                                 res.extend_from_slice(&byte_utils::be48_to_array(idx));
 517                                 res.extend_from_slice(&pubkey.serialize());
 518                                 match second_option {
 519                                         Some(second_pubkey) => {
 520                                                 res.extend_from_slice(&second_pubkey.serialize());
 521                                         },
 522                                         None => {
 523                                                 res.extend_from_slice(&[0; 33]);
 524                                         },
 525                                 }
 526                         },
 527                         None => {
 528                                 res.extend_from_slice(&byte_utils::be48_to_array(0));
 529                         },
 530                 }
 531
 532                 res.extend_from_slice(&byte_utils::be16_to_array(self.our_to_self_delay));
 533                 res.extend_from_slice(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()));
 534
 535                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 536                         res.extend_from_slice(secret);
 537                         res.extend_from_slice(&byte_utils::be64_to_array(*idx));
 538                 }
 539
 540                 macro_rules! serialize_htlc_in_commitment {
 541                         ($htlc_output: expr) => {
 542                                 res.push($htlc_output.offered as u8);
 543                                 res.extend_from_slice(&byte_utils::be64_to_array($htlc_output.amount_msat));
 544                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.cltv_expiry));
 545                                 res.extend_from_slice(&$htlc_output.payment_hash);
 546                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.transaction_output_index));
 547                         }
 548                 }
 549
 550                 res.extend_from_slice(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64));
 551                 for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
 552                         res.extend_from_slice(&txid[..]);
 553                         res.extend_from_slice(&byte_utils::be64_to_array(htlc_outputs.len() as u64));
 554                         for htlc_output in htlc_outputs.iter() {
 555                                 serialize_htlc_in_commitment!(htlc_output);
 556                         }
 557                 }
 558
 559                 {
 560                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
 561                         res.extend_from_slice(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64));
 562                         for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
 563                                 res.extend_from_slice(&txid[..]);
 564                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 565                         }
 566                 }
 567
 568                 if for_local_storage {
 569                         res.extend_from_slice(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64));
 570                         for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 571                                 res.extend_from_slice(payment_hash);
 572                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 573                         }
 574                 } else {
 575                         res.extend_from_slice(&byte_utils::be64_to_array(0));
 576                 }
 577
 578                 macro_rules! serialize_local_tx {
 579                         ($local_tx: expr) => {
 580                                 let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
 581                                 res.extend_from_slice(&byte_utils::be64_to_array(tx_ser.len() as u64));
 582                                 res.extend_from_slice(&tx_ser);
 583
 584                                 res.extend_from_slice(&$local_tx.revocation_key.serialize());
 585                                 res.extend_from_slice(&$local_tx.a_htlc_key.serialize());
 586                                 res.extend_from_slice(&$local_tx.b_htlc_key.serialize());
 587                                 res.extend_from_slice(&$local_tx.delayed_payment_key.serialize());
 588
 589                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.feerate_per_kw));
 590                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64));
 591                                 for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
 592                                         serialize_htlc_in_commitment!(htlc_output);
 593                                         res.extend_from_slice(&their_sig.serialize_compact(&self.secp_ctx));
 594                                         res.extend_from_slice(&our_sig.serialize_compact(&self.secp_ctx));
 595                                 }
 596                         }
 597                 }
 598
 599                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 600                         res.push(1);
 601                         serialize_local_tx!(prev_local_tx);
 602                 } else {
 603                         res.push(0);
 604                 }
 605
 606                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 607                         res.push(1);
 608                         serialize_local_tx!(cur_local_tx);
 609                 } else {
 610                         res.push(0);
 611                 }
 612
 613                 res.extend_from_slice(&byte_utils::be64_to_array(self.payment_preimages.len() as u64));
 614                 for payment_preimage in self.payment_preimages.values() {
 615                         res.extend_from_slice(payment_preimage);
 616                 }
 617
 618                 res.extend_from_slice(&byte_utils::be64_to_array(self.destination_script.len() as u64));
 619                 res.extend_from_slice(&self.destination_script[..]);
 620
 621                 res
 622         }
 623
 624         /// Encodes this monitor into a byte array, suitable for writing to disk.
 625         pub fn serialize_for_disk(&self) -> Vec<u8> {
 626                 self.serialize(true)
 627         }
 628
 629         /// Encodes this monitor into a byte array, suitable for sending to a remote watchtower
 630         pub fn serialize_for_watchtower(&self) -> Vec<u8> {
 631                 self.serialize(false)
 632         }
 633
 634         /// Attempts to decode a serialized monitor
 635         pub fn deserialize(data: &[u8]) -> Option<Self> {
 636                 let mut read_pos = 0;
 637                 macro_rules! read_bytes {
 638                         ($byte_count: expr) => {
 639                                 {
 640                                         if ($byte_count as usize) > data.len() - read_pos {
 641                                                 return None;
 642                                         }
 643                                         read_pos += $byte_count as usize;
 644                                         &data[read_pos - $byte_count as usize..read_pos]
 645                                 }
 646                         }
 647                 }
 648
 649                 let secp_ctx = Secp256k1::new();
 650                 macro_rules! unwrap_obj {
 651                         ($key: expr) => {
 652                                 match $key {
 653                                         Ok(res) => res,
 654                                         Err(_) => return None,
 655                                 }
 656                         }
 657                 }
 658
 659                 let _ver = read_bytes!(1)[0];
 660                 let min_ver = read_bytes!(1)[0];
 661                 if min_ver > SERIALIZATION_VERSION {
 662                         return None;
 663                 }
 664
 665                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
 666                 // barely-init'd ChannelMonitors that we can't do anything with.
 667                 let funding_txo = Some(OutPoint {
 668                         txid: Sha256dHash::from(read_bytes!(32)),
 669                         index: byte_utils::slice_to_be16(read_bytes!(2)),
 670                 });
 671                 let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
 672
 673                 let key_storage = match read_bytes!(1)[0] {
 674                         0 => {
 675                                 KeyStorage::PrivMode {
 676                                         revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 677                                         htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 678                                 }
 679                         },
 680                         _ => return None,
 681                 };
 682
 683                 let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 684                 let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 685
 686                 let their_cur_revocation_points = {
 687                         let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
 688                         if first_idx == 0 {
 689                                 None
 690                         } else {
 691                                 let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 692                                 let second_point_slice = read_bytes!(33);
 693                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
 694                                         Some((first_idx, first_point, None))
 695                                 } else {
 696                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
 697                                 }
 698                         }
 699                 };
 700
 701                 let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
 702                 let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
 703
 704                 let mut old_secrets = [([0; 32], 1 << 48); 49];
 705                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
 706                         secret.copy_from_slice(read_bytes!(32));
 707                         *idx = byte_utils::slice_to_be64(read_bytes!(8));
 708                 }
 709
 710                 macro_rules! read_htlc_in_commitment {
 711                         () => {
 712                                 {
 713                                         let offered = match read_bytes!(1)[0] {
 714                                                 0 => false, 1 => true,
 715                                                 _ => return None,
 716                                         };
 717                                         let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
 718                                         let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
 719                                         let mut payment_hash = [0; 32];
 720                                         payment_hash[..].copy_from_slice(read_bytes!(32));
 721                                         let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
 722
 723                                         HTLCOutputInCommitment {
 724                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
 725                                         }
 726                                 }
 727                         }
 728                 }
 729
 730                 let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
 731                 if remote_claimable_outpoints_len > data.len() as u64 / 64 { return None; }
 732                 let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
 733                 for _ in 0..remote_claimable_outpoints_len {
 734                         let txid = Sha256dHash::from(read_bytes!(32));
 735                         let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
 736                         if outputs_count > data.len() as u64 * 32 { return None; }
 737                         let mut outputs = Vec::with_capacity(outputs_count as usize);
 738                         for _ in 0..outputs_count {
 739                                 outputs.push(read_htlc_in_commitment!());
 740                         }
 741                         if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
 742                                 return None;
 743                         }
 744                 }
 745
 746                 let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
 747                 if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return None; }
 748                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
 749                 for _ in 0..remote_commitment_txn_on_chain_len {
 750                         let txid = Sha256dHash::from(read_bytes!(32));
 751                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 752                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
 753                                 return None;
 754                         }
 755                 }
 756
 757                 let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
 758                 if remote_hash_commitment_number_len > data.len() as u64 / 32 { return None; }
 759                 let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
 760                 for _ in 0..remote_hash_commitment_number_len {
 761                         let mut txid = [0; 32];
 762                         txid[..].copy_from_slice(read_bytes!(32));
 763                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 764                         if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
 765                                 return None;
 766                         }
 767                 }
 768
 769                 macro_rules! read_local_tx {
 770                         () => {
 771                                 {
 772                                         let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
 773                                         let tx_ser = read_bytes!(tx_len);
 774                                         let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
 775                                         if serialize::serialize(&tx).unwrap() != tx_ser {
 776                                                 // We check that the tx re-serializes to the same form to ensure there is
 777                                                 // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
 778                                                 // all that well.
 779                                                 return None;
 780                                         }
 781
 782                                         let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 783                                         let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 784                                         let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 785                                         let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 786                                         let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
 787
 788                                         let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
 789                                         if htlc_outputs_len > data.len() as u64 / 128 { return None; }
 790                                         let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
 791                                         for _ in 0..htlc_outputs_len {
 792                                                 htlc_outputs.push((read_htlc_in_commitment!(),
 793                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
 794                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
 795                                         }
 796
 797                                         LocalSignedTx {
 798                                                 txid: tx.txid(),
 799                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
 800                                         }
 801                                 }
 802                         }
 803                 }
 804
 805                 let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
 806                         0 => None,
 807                         1 => {
 808                                 Some(read_local_tx!())
 809                         },
 810                         _ => return None,
 811                 };
 812
 813                 let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
 814                         0 => None,
 815                         1 => {
 816                                 Some(read_local_tx!())
 817                         },
 818                         _ => return None,
 819                 };
 820
 821                 let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
 822                 if payment_preimages_len > data.len() as u64 / 32 { return None; }
 823                 let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
 824                 let mut sha = Sha256::new();
 825                 for _ in 0..payment_preimages_len {
 826                         let mut preimage = [0; 32];
 827                         preimage[..].copy_from_slice(read_bytes!(32));
 828                         sha.reset();
 829                         sha.input(&preimage);
 830                         let mut hash = [0; 32];
 831                         sha.result(&mut hash);
 832                         if let Some(_) = payment_preimages.insert(hash, preimage) {
 833                                 return None;
 834                         }
 835                 }
 836
 837                 let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
 838                 let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
 839
 840                 Some(ChannelMonitor {
 841                         funding_txo,
 842                         commitment_transaction_number_obscure_factor,
 843
 844                         key_storage,
 845                         delayed_payment_base_key,
 846                         their_htlc_base_key,
 847                         their_cur_revocation_points,
 848
 849                         our_to_self_delay,
 850                         their_to_self_delay,
 851
 852                         old_secrets,
 853                         remote_claimable_outpoints,
 854                         remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
 855                         remote_hash_commitment_number,
 856
 857                         prev_local_signed_commitment_tx,
 858                         current_local_signed_commitment_tx,
 859
 860                         payment_preimages,
 861
 862                         destination_script,
 863                         secp_ctx,
 864                 })
 865         }
 866
 867         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 868         //we want to leave out (eg funding_txo, etc).
 869
 870         /// Can only fail if idx is < get_min_seen_secret
 871         pub fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 872                 for i in 0..self.old_secrets.len() {
 873                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 874                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 875                         }
 876                 }
 877                 assert!(idx < self.get_min_seen_secret());
 878                 Err(HandleError{err: "idx too low", msg: None})
 879         }
 880
 881         pub fn get_min_seen_secret(&self) -> u64 {
 882                 //TODO This can be optimized?
 883                 let mut min = 1 << 48;
 884                 for &(_, idx) in self.old_secrets.iter() {
 885                         if idx < min {
 886                                 min = idx;
 887                         }
 888                 }
 889                 min
 890         }
 891
 892         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 893         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 894         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 895         /// HTLC-Success/HTLC-Timeout transactions, and claim them using the revocation key (if
 896         /// applicable) as well.
 897         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> Vec<Transaction> {
 898                 // Most secp and related errors trying to create keys means we have no hope of constructing
 899                 // a spend transaction...so we return no transactions to broadcast
 900                 let mut txn_to_broadcast = Vec::new();
 901                 macro_rules! ignore_error {
 902                         ( $thing : expr ) => {
 903                                 match $thing {
 904                                         Ok(a) => a,
 905                                         Err(_) => return txn_to_broadcast
 906                                 }
 907                         };
 908                 }
 909
 910                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 911                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 912
 913                 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);
 914                 if commitment_number >= self.get_min_seen_secret() {
 915                         let secret = self.get_secret(commitment_number).unwrap();
 916                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 917                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 918                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 919                                         let per_commitment_point = ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key));
 920                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))),
 921                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key)))))
 922                                 },
 923                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 924                                         let per_commitment_point = ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key));
 925                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 926                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 927                                 },
 928                         };
 929                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key)), &self.delayed_payment_base_key));
 930                         let a_htlc_key = match self.their_htlc_base_key {
 931                                 None => return txn_to_broadcast,
 932                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key)), &their_htlc_base_key)),
 933                         };
 934
 935                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 936                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 937
 938                         let mut total_value = 0;
 939                         let mut values = Vec::new();
 940                         let mut inputs = Vec::new();
 941                         let mut htlc_idxs = Vec::new();
 942
 943                         for (idx, outp) in tx.output.iter().enumerate() {
 944                                 if outp.script_pubkey == revokeable_p2wsh {
 945                                         inputs.push(TxIn {
 946                                                 prev_hash: commitment_txid,
 947                                                 prev_index: idx as u32,
 948                                                 script_sig: Script::new(),
 949                                                 sequence: 0xfffffffd,
 950                                                 witness: Vec::new(),
 951                                         });
 952                                         htlc_idxs.push(None);
 953                                         values.push(outp.value);
 954                                         total_value += outp.value;
 955                                         break; // There can only be one of these
 956                                 }
 957                         }
 958
 959                         macro_rules! sign_input {
 960                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 961                                         {
 962                                                 let (sig, redeemscript) = match self.key_storage {
 963                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
 964                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
 965                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
 966                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
 967                                                                 };
 968                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 969                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
 970                                                                 (ignore_error!(self.secp_ctx.sign(&sighash, &revocation_key)), redeemscript)
 971                                                         },
 972                                                         KeyStorage::SigsMode { .. } => {
 973                                                                 unimplemented!();
 974                                                         }
 975                                                 };
 976                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 977                                                 $input.witness[0].push(SigHashType::All as u8);
 978                                                 if $htlc_idx.is_none() {
 979                                                         $input.witness.push(vec!(1));
 980                                                 } else {
 981                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
 982                                                 }
 983                                                 $input.witness.push(redeemscript.into_vec());
 984                                         }
 985                                 }
 986                         }
 987
 988                         if let Some(per_commitment_data) = per_commitment_option {
 989                                 inputs.reserve_exact(per_commitment_data.len());
 990
 991                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
 992                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 993                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
 994                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
 995                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
 996                                                 return txn_to_broadcast; // Corrupted per_commitment_data, fuck this user
 997                                         }
 998                                         let input = TxIn {
 999                                                 prev_hash: commitment_txid,
1000                                                 prev_index: htlc.transaction_output_index,
1001                                                 script_sig: Script::new(),
1002                                                 sequence: 0xfffffffd,
1003                                                 witness: Vec::new(),
1004                                         };
1005                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1006                                                 inputs.push(input);
1007                                                 htlc_idxs.push(Some(idx));
1008                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
1009                                                 total_value += htlc.amount_msat / 1000;
1010                                         } else {
1011                                                 let mut single_htlc_tx = Transaction {
1012                                                         version: 2,
1013                                                         lock_time: 0,
1014                                                         input: vec![input],
1015                                                         output: vec!(TxOut {
1016                                                                 script_pubkey: self.destination_script.clone(),
1017                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1018                                                         }),
1019                                                 };
1020                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1021                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
1022                                                 txn_to_broadcast.push(single_htlc_tx); // TODO: This is not yet tested in ChannelManager!
1023                                         }
1024                                 }
1025                         }
1026
1027                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours
1028                                 // We're definitely a remote commitment transaction!
1029                                 // TODO: Register commitment_txid with the ChainWatchInterface!
1030                                 self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1031                         }
1032                         if inputs.is_empty() { return txn_to_broadcast; } // Nothing to be done...probably a false positive/local tx
1033
1034                         let outputs = vec!(TxOut {
1035                                 script_pubkey: self.destination_script.clone(),
1036                                 value: total_value, //TODO: - fee
1037                         });
1038                         let mut spend_tx = Transaction {
1039                                 version: 2,
1040                                 lock_time: 0,
1041                                 input: inputs,
1042                                 output: outputs,
1043                         };
1044
1045                         let mut values_drain = values.drain(..);
1046                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1047
1048                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
1049                                 let value = values_drain.next().unwrap();
1050                                 sign_input!(sighash_parts, input, htlc_idx, value);
1051                         }
1052
1053                         txn_to_broadcast.push(spend_tx);
1054                 } else if let Some(per_commitment_data) = per_commitment_option {
1055                         // While this isn't useful yet, there is a potential race where if a counterparty
1056                         // revokes a state at the same time as the commitment transaction for that state is
1057                         // confirmed, and the watchtower receives the block before the user, the user could
1058                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
1059                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1060                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
1061                         // insert it here.
1062                         self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1063
1064                         if let Some(revocation_points) = self.their_cur_revocation_points {
1065                                 let revocation_point_option =
1066                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1067                                         else if let Some(point) = revocation_points.2.as_ref() {
1068                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1069                                         } else { None };
1070                                 if let Some(revocation_point) = revocation_point_option {
1071                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
1072                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
1073                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))),
1074                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key)))))
1075                                                 },
1076                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
1077                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
1078                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1079                                                 },
1080                                         };
1081                                         let a_htlc_key = match self.their_htlc_base_key {
1082                                                 None => return txn_to_broadcast,
1083                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1084                                         };
1085
1086                                         let mut total_value = 0;
1087                                         let mut values = Vec::new();
1088                                         let mut inputs = Vec::new();
1089
1090                                         macro_rules! sign_input {
1091                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
1092                                                         {
1093                                                                 let (sig, redeemscript) = match self.key_storage {
1094                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
1095                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
1096                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1097                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
1098                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
1099                                                                                 (ignore_error!(self.secp_ctx.sign(&sighash, &htlc_key)), redeemscript)
1100                                                                         },
1101                                                                         KeyStorage::SigsMode { .. } => {
1102                                                                                 unimplemented!();
1103                                                                         }
1104                                                                 };
1105                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1106                                                                 $input.witness[0].push(SigHashType::All as u8);
1107                                                                 $input.witness.push($preimage);
1108                                                                 $input.witness.push(redeemscript.into_vec());
1109                                                         }
1110                                                 }
1111                                         }
1112
1113                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
1114                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1115                                                         let input = TxIn {
1116                                                                 prev_hash: commitment_txid,
1117                                                                 prev_index: htlc.transaction_output_index,
1118                                                                 script_sig: Script::new(),
1119                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
1120                                                                 witness: Vec::new(),
1121                                                         };
1122                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1123                                                                 inputs.push(input);
1124                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
1125                                                                 total_value += htlc.amount_msat / 1000;
1126                                                         } else {
1127                                                                 let mut single_htlc_tx = Transaction {
1128                                                                         version: 2,
1129                                                                         lock_time: 0,
1130                                                                         input: vec![input],
1131                                                                         output: vec!(TxOut {
1132                                                                                 script_pubkey: self.destination_script.clone(),
1133                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1134                                                                         }),
1135                                                                 };
1136                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1137                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
1138                                                                 txn_to_broadcast.push(single_htlc_tx);
1139                                                         }
1140                                                 }
1141                                         }
1142
1143                                         if inputs.is_empty() { return txn_to_broadcast; } // Nothing to be done...probably a false positive/local tx
1144
1145                                         let outputs = vec!(TxOut {
1146                                                 script_pubkey: self.destination_script.clone(),
1147                                                 value: total_value, //TODO: - fee
1148                                         });
1149                                         let mut spend_tx = Transaction {
1150                                                 version: 2,
1151                                                 lock_time: 0,
1152                                                 input: inputs,
1153                                                 output: outputs,
1154                                         };
1155
1156                                         let mut values_drain = values.drain(..);
1157                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1158
1159                                         for input in spend_tx.input.iter_mut() {
1160                                                 let value = values_drain.next().unwrap();
1161                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
1162                                         }
1163
1164                                         txn_to_broadcast.push(spend_tx);
1165                                 }
1166                         }
1167                 } else {
1168                         //TODO: For each input check if its in our remote_commitment_txn_on_chain map!
1169                 }
1170
1171                 txn_to_broadcast
1172         }
1173
1174         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
1175                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1176
1177                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
1178                         if htlc.offered {
1179                                 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);
1180
1181                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1182
1183                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1184                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1185                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1186                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1187
1188                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1189                                 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_vec());
1190
1191                                 res.push(htlc_timeout_tx);
1192                         } else {
1193                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1194                                         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);
1195
1196                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1197
1198                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1199                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1200                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1201                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1202
1203                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
1204                                         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_vec());
1205
1206                                         res.push(htlc_success_tx);
1207                                 }
1208                         }
1209                 }
1210
1211                 res
1212         }
1213
1214         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1215         /// revoked using data in local_claimable_outpoints.
1216         /// Should not be used if check_spend_revoked_transaction succeeds.
1217         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
1218                 let commitment_txid = tx.txid();
1219                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1220                         if local_tx.txid == commitment_txid {
1221                                 return self.broadcast_by_local_state(local_tx);
1222                         }
1223                 }
1224                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1225                         if local_tx.txid == commitment_txid {
1226                                 return self.broadcast_by_local_state(local_tx);
1227                         }
1228                 }
1229                 Vec::new()
1230         }
1231
1232         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface) {
1233                 for tx in txn_matched {
1234                         for txin in tx.input.iter() {
1235                                 if self.funding_txo.is_none() || (txin.prev_hash == self.funding_txo.unwrap().txid && txin.prev_index == self.funding_txo.unwrap().index as u32) {
1236                                         let mut txn = self.check_spend_remote_transaction(tx, height);
1237                                         if txn.is_empty() {
1238                                                 txn = self.check_spend_local_transaction(tx, height);
1239                                         }
1240                                         for tx in txn.iter() {
1241                                                 broadcaster.broadcast_transaction(tx);
1242                                         }
1243                                 }
1244                         }
1245                 }
1246                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1247                         let mut needs_broadcast = false;
1248                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1249                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1250                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1251                                                 needs_broadcast = true;
1252                                         }
1253                                 }
1254                         }
1255
1256                         if needs_broadcast {
1257                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1258                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
1259                                         broadcaster.broadcast_transaction(&tx);
1260                                 }
1261                         }
1262                 }
1263         }
1264
1265         pub fn would_broadcast_at_height(&self, height: u32) -> bool {
1266                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1267                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1268                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1269                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1270                                                 return true;
1271                                         }
1272                                 }
1273                         }
1274                 }
1275                 false
1276         }
1277 }
1278
1279 #[cfg(test)]
1280 mod tests {
1281         use bitcoin::util::misc::hex_bytes;
1282         use bitcoin::blockdata::script::Script;
1283         use bitcoin::blockdata::transaction::Transaction;
1284         use crypto::digest::Digest;
1285         use ln::channelmonitor::ChannelMonitor;
1286         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
1287         use util::sha2::Sha256;
1288         use secp256k1::key::{SecretKey,PublicKey};
1289         use secp256k1::{Secp256k1, Signature};
1290         use rand::{thread_rng,Rng};
1291
1292         #[test]
1293         fn test_per_commitment_storage() {
1294                 // Test vectors from BOLT 3:
1295                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1296                 let mut monitor: ChannelMonitor;
1297                 let secp_ctx = Secp256k1::new();
1298
1299                 macro_rules! test_secrets {
1300                         () => {
1301                                 let mut idx = 281474976710655;
1302                                 for secret in secrets.iter() {
1303                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1304                                         idx -= 1;
1305                                 }
1306                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1307                                 assert!(monitor.get_secret(idx).is_err());
1308                         };
1309                 }
1310
1311                 {
1312                         // insert_secret correct sequence
1313                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1314                         secrets.clear();
1315
1316                         secrets.push([0; 32]);
1317                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1318                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1319                         test_secrets!();
1320
1321                         secrets.push([0; 32]);
1322                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1323                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1324                         test_secrets!();
1325
1326                         secrets.push([0; 32]);
1327                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1328                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1329                         test_secrets!();
1330
1331                         secrets.push([0; 32]);
1332                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1333                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1334                         test_secrets!();
1335
1336                         secrets.push([0; 32]);
1337                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1338                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1339                         test_secrets!();
1340
1341                         secrets.push([0; 32]);
1342                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1343                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1344                         test_secrets!();
1345
1346                         secrets.push([0; 32]);
1347                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1348                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1349                         test_secrets!();
1350
1351                         secrets.push([0; 32]);
1352                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1353                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
1354                         test_secrets!();
1355                 }
1356
1357                 {
1358                         // insert_secret #1 incorrect
1359                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1360                         secrets.clear();
1361
1362                         secrets.push([0; 32]);
1363                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1364                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1365                         test_secrets!();
1366
1367                         secrets.push([0; 32]);
1368                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1369                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
1370                                         "Previous secret did not match new one");
1371                 }
1372
1373                 {
1374                         // insert_secret #2 incorrect (#1 derived from incorrect)
1375                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1376                         secrets.clear();
1377
1378                         secrets.push([0; 32]);
1379                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1380                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1381                         test_secrets!();
1382
1383                         secrets.push([0; 32]);
1384                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1385                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1386                         test_secrets!();
1387
1388                         secrets.push([0; 32]);
1389                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1390                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1391                         test_secrets!();
1392
1393                         secrets.push([0; 32]);
1394                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1395                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1396                                         "Previous secret did not match new one");
1397                 }
1398
1399                 {
1400                         // insert_secret #3 incorrect
1401                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1402                         secrets.clear();
1403
1404                         secrets.push([0; 32]);
1405                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1406                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1407                         test_secrets!();
1408
1409                         secrets.push([0; 32]);
1410                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1411                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1412                         test_secrets!();
1413
1414                         secrets.push([0; 32]);
1415                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1416                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1417                         test_secrets!();
1418
1419                         secrets.push([0; 32]);
1420                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1421                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1422                                         "Previous secret did not match new one");
1423                 }
1424
1425                 {
1426                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1427                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1428                         secrets.clear();
1429
1430                         secrets.push([0; 32]);
1431                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1432                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1433                         test_secrets!();
1434
1435                         secrets.push([0; 32]);
1436                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1437                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1438                         test_secrets!();
1439
1440                         secrets.push([0; 32]);
1441                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1442                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1443                         test_secrets!();
1444
1445                         secrets.push([0; 32]);
1446                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1447                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1448                         test_secrets!();
1449
1450                         secrets.push([0; 32]);
1451                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1452                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1453                         test_secrets!();
1454
1455                         secrets.push([0; 32]);
1456                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1457                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1458                         test_secrets!();
1459
1460                         secrets.push([0; 32]);
1461                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1462                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1463                         test_secrets!();
1464
1465                         secrets.push([0; 32]);
1466                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1467                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1468                                         "Previous secret did not match new one");
1469                 }
1470
1471                 {
1472                         // insert_secret #5 incorrect
1473                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1474                         secrets.clear();
1475
1476                         secrets.push([0; 32]);
1477                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1478                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1479                         test_secrets!();
1480
1481                         secrets.push([0; 32]);
1482                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1483                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1484                         test_secrets!();
1485
1486                         secrets.push([0; 32]);
1487                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1488                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1489                         test_secrets!();
1490
1491                         secrets.push([0; 32]);
1492                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1493                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1494                         test_secrets!();
1495
1496                         secrets.push([0; 32]);
1497                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1498                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1499                         test_secrets!();
1500
1501                         secrets.push([0; 32]);
1502                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1503                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1504                                         "Previous secret did not match new one");
1505                 }
1506
1507                 {
1508                         // insert_secret #6 incorrect (5 derived from incorrect)
1509                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1510                         secrets.clear();
1511
1512                         secrets.push([0; 32]);
1513                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1514                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1515                         test_secrets!();
1516
1517                         secrets.push([0; 32]);
1518                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1519                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1520                         test_secrets!();
1521
1522                         secrets.push([0; 32]);
1523                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1524                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1525                         test_secrets!();
1526
1527                         secrets.push([0; 32]);
1528                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1529                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1530                         test_secrets!();
1531
1532                         secrets.push([0; 32]);
1533                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1534                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1535                         test_secrets!();
1536
1537                         secrets.push([0; 32]);
1538                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1539                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1540                         test_secrets!();
1541
1542                         secrets.push([0; 32]);
1543                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1544                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1545                         test_secrets!();
1546
1547                         secrets.push([0; 32]);
1548                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1549                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1550                                         "Previous secret did not match new one");
1551                 }
1552
1553                 {
1554                         // insert_secret #7 incorrect
1555                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1556                         secrets.clear();
1557
1558                         secrets.push([0; 32]);
1559                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1560                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1561                         test_secrets!();
1562
1563                         secrets.push([0; 32]);
1564                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1565                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1566                         test_secrets!();
1567
1568                         secrets.push([0; 32]);
1569                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1570                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1571                         test_secrets!();
1572
1573                         secrets.push([0; 32]);
1574                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1575                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1576                         test_secrets!();
1577
1578                         secrets.push([0; 32]);
1579                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1580                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1581                         test_secrets!();
1582
1583                         secrets.push([0; 32]);
1584                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1585                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1586                         test_secrets!();
1587
1588                         secrets.push([0; 32]);
1589                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1590                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1591                         test_secrets!();
1592
1593                         secrets.push([0; 32]);
1594                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1595                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1596                                         "Previous secret did not match new one");
1597                 }
1598
1599                 {
1600                         // insert_secret #8 incorrect
1601                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1602                         secrets.clear();
1603
1604                         secrets.push([0; 32]);
1605                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1606                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1607                         test_secrets!();
1608
1609                         secrets.push([0; 32]);
1610                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1611                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1612                         test_secrets!();
1613
1614                         secrets.push([0; 32]);
1615                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1616                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1617                         test_secrets!();
1618
1619                         secrets.push([0; 32]);
1620                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1621                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1622                         test_secrets!();
1623
1624                         secrets.push([0; 32]);
1625                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1626                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1627                         test_secrets!();
1628
1629                         secrets.push([0; 32]);
1630                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1631                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1632                         test_secrets!();
1633
1634                         secrets.push([0; 32]);
1635                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1636                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1637                         test_secrets!();
1638
1639                         secrets.push([0; 32]);
1640                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1641                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1642                                         "Previous secret did not match new one");
1643                 }
1644         }
1645
1646         #[test]
1647         fn test_prune_preimages() {
1648                 let secp_ctx = Secp256k1::new();
1649                 let dummy_sig = Signature::from_der(&secp_ctx, &hex_bytes("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap();
1650
1651                 macro_rules! dummy_keys {
1652                         () => {
1653                                 TxCreationKeys {
1654                                         per_commitment_point: PublicKey::new(),
1655                                         revocation_key: PublicKey::new(),
1656                                         a_htlc_key: PublicKey::new(),
1657                                         b_htlc_key: PublicKey::new(),
1658                                         a_delayed_payment_key: PublicKey::new(),
1659                                         b_payment_key: PublicKey::new(),
1660                                 }
1661                         }
1662                 }
1663                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
1664
1665                 let mut preimages = Vec::new();
1666                 {
1667                         let mut rng  = thread_rng();
1668                         for _ in 0..20 {
1669                                 let mut preimage = [0; 32];
1670                                 rng.fill_bytes(&mut preimage);
1671                                 let mut sha = Sha256::new();
1672                                 sha.input(&preimage);
1673                                 let mut hash = [0; 32];
1674                                 sha.result(&mut hash);
1675                                 preimages.push((preimage, hash));
1676                         }
1677                 }
1678
1679                 macro_rules! preimages_slice_to_htlc_outputs {
1680                         ($preimages_slice: expr) => {
1681                                 {
1682                                         let mut res = Vec::new();
1683                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
1684                                                 res.push(HTLCOutputInCommitment {
1685                                                         offered: true,
1686                                                         amount_msat: 0,
1687                                                         cltv_expiry: 0,
1688                                                         payment_hash: preimage.1.clone(),
1689                                                         transaction_output_index: idx as u32,
1690                                                 });
1691                                         }
1692                                         res
1693                                 }
1694                         }
1695                 }
1696                 macro_rules! preimages_to_local_htlcs {
1697                         ($preimages_slice: expr) => {
1698                                 {
1699                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
1700                                         let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect();
1701                                         res
1702                                 }
1703                         }
1704                 }
1705
1706                 macro_rules! test_preimages_exist {
1707                         ($preimages_slice: expr, $monitor: expr) => {
1708                                 for preimage in $preimages_slice {
1709                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
1710                                 }
1711                         }
1712                 }
1713
1714                 // Prune with one old state and a local commitment tx holding a few overlaps with the
1715                 // old state.
1716                 let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1717                 monitor.set_their_to_self_delay(10);
1718
1719                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
1720                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655);
1721                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654);
1722                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653);
1723                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652);
1724                 for &(ref preimage, ref hash) in preimages.iter() {
1725                         monitor.provide_payment_preimage(hash, preimage);
1726                 }
1727
1728                 // Now provide a secret, pruning preimages 10-15
1729                 let mut secret = [0; 32];
1730                 secret[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1731                 monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1732                 assert_eq!(monitor.payment_preimages.len(), 15);
1733                 test_preimages_exist!(&preimages[0..10], monitor);
1734                 test_preimages_exist!(&preimages[15..20], monitor);
1735
1736                 // Now provide a further secret, pruning preimages 15-17
1737                 secret[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1738                 monitor.provide_secret(281474976710654, secret.clone(), None).unwrap();
1739                 assert_eq!(monitor.payment_preimages.len(), 13);
1740                 test_preimages_exist!(&preimages[0..10], monitor);
1741                 test_preimages_exist!(&preimages[17..20], monitor);
1742
1743                 // Now update local commitment tx info, pruning only element 18 as we still care about the
1744                 // previous commitment tx's preimages too
1745                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
1746                 secret[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1747                 monitor.provide_secret(281474976710653, secret.clone(), None).unwrap();
1748                 assert_eq!(monitor.payment_preimages.len(), 12);
1749                 test_preimages_exist!(&preimages[0..10], monitor);
1750                 test_preimages_exist!(&preimages[18..20], monitor);
1751
1752                 // But if we do it again, we'll prune 5-10
1753                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
1754                 secret[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1755                 monitor.provide_secret(281474976710652, secret.clone(), None).unwrap();
1756                 assert_eq!(monitor.payment_preimages.len(), 5);
1757                 test_preimages_exist!(&preimages[0..5], monitor);
1758         }
1759
1760         // Further testing is done in the ChannelManager integration tests.
1761 }