_ 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::transaction::OutPoint as BitcoinOutPoint;
   4 use bitcoin::blockdata::script::Script;
   5 use bitcoin::network::serialize;
   6 use bitcoin::util::hash::Sha256dHash;
   7 use bitcoin::util::bip143;
   8
   9 use crypto::digest::Digest;
  10
  11 use secp256k1::{Secp256k1,Message,Signature};
  12 use secp256k1::key::{SecretKey,PublicKey};
  13 use secp256k1;
  14
  15 use ln::msgs::HandleError;
  16 use ln::chan_utils;
  17 use ln::chan_utils::HTLCOutputInCommitment;
  18 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
  19 use chain::transaction::OutPoint;
  20 use util::sha2::Sha256;
  21 use util::byte_utils;
  22
  23 use std::collections::HashMap;
  24 use std::sync::{Arc,Mutex};
  25 use std::{hash,cmp};
  26
  27 pub enum ChannelMonitorUpdateErr {
  28         /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
  29         /// to succeed at some point in the future).
  30         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  31         /// submitting new commitment transactions to the remote party.
  32         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  33         /// the channel to an operational state.
  34         TemporaryFailure,
  35         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  36         /// different watchtower and cannot update with all watchtowers that were previously informed
  37         /// of this channel). This will force-close the channel in question.
  38         PermanentFailure,
  39 }
  40
  41 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
  42 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
  43 /// events to it, while also taking any add_update_monitor events and passing them to some remote
  44 /// server(s).
  45 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
  46 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
  47 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
  48 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
  49 pub trait ManyChannelMonitor: Send + Sync {
  50         /// Adds or updates a monitor for the given `funding_txo`.
  51         /// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
  52         /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
  53         /// any spends of it.
  54         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
  55 }
  56
  57 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
  58 /// watchtower or watch our own channels.
  59 /// Note that you must provide your own key by which to refer to channels.
  60 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
  61 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
  62 /// index by a PublicKey which is required to sign any updates.
  63 /// If you're using this for local monitoring of your own channels, you probably want to use
  64 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
  65 pub struct SimpleManyChannelMonitor<Key> {
  66         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  67         chain_monitor: Arc<ChainWatchInterface>,
  68         broadcaster: Arc<BroadcasterInterface>
  69 }
  70
  71 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
  72         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
  73                 let monitors = self.monitors.lock().unwrap();
  74                 for monitor in monitors.values() {
  75                         let txn_outputs = monitor.block_connected(txn_matched, height, &*self.broadcaster);
  76                         for (ref txid, ref outputs) in txn_outputs {
  77                                 for (idx, output) in outputs.iter().enumerate() {
  78                                         self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
  79                                 }
  80                         }
  81                 }
  82         }
  83
  84         fn block_disconnected(&self, _: &BlockHeader) { }
  85 }
  86
  87 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
  88         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
  89                 let res = Arc::new(SimpleManyChannelMonitor {
  90                         monitors: Mutex::new(HashMap::new()),
  91                         chain_monitor,
  92                         broadcaster
  93                 });
  94                 let weak_res = Arc::downgrade(&res);
  95                 res.chain_monitor.register_listener(weak_res);
  96                 res
  97         }
  98
  99         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
 100                 let mut monitors = self.monitors.lock().unwrap();
 101                 match monitors.get_mut(&key) {
 102                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
 103                         None => {}
 104                 };
 105                 match &monitor.funding_txo {
 106                         &None => self.chain_monitor.watch_all_txn(),
 107                         &Some((ref outpoint, ref script)) => {
 108                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
 109                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
 110                         },
 111                 }
 112                 monitors.insert(key, monitor);
 113                 Ok(())
 114         }
 115 }
 116
 117 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 118         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 119                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 120                         Ok(_) => Ok(()),
 121                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 122                 }
 123         }
 124 }
 125
 126 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 127 /// instead claiming it in its own individual transaction.
 128 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 129 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 130 /// HTLC-Success transaction.
 131 const CLTV_CLAIM_BUFFER: u32 = 6;
 132
 133 #[derive(Clone, PartialEq)]
 134 enum KeyStorage {
 135         PrivMode {
 136                 revocation_base_key: SecretKey,
 137                 htlc_base_key: SecretKey,
 138         },
 139         SigsMode {
 140                 revocation_base_key: PublicKey,
 141                 htlc_base_key: PublicKey,
 142                 sigs: HashMap<Sha256dHash, Signature>,
 143         }
 144 }
 145
 146 #[derive(Clone, PartialEq)]
 147 struct LocalSignedTx {
 148         /// txid of the transaction in tx, just used to make comparison faster
 149         txid: Sha256dHash,
 150         tx: Transaction,
 151         revocation_key: PublicKey,
 152         a_htlc_key: PublicKey,
 153         b_htlc_key: PublicKey,
 154         delayed_payment_key: PublicKey,
 155         feerate_per_kw: u64,
 156         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 157 }
 158
 159 const SERIALIZATION_VERSION: u8 = 1;
 160 const MIN_SERIALIZATION_VERSION: u8 = 1;
 161
 162 pub struct ChannelMonitor {
 163         funding_txo: Option<(OutPoint, Script)>,
 164         commitment_transaction_number_obscure_factor: u64,
 165
 166         key_storage: KeyStorage,
 167         delayed_payment_base_key: PublicKey,
 168         their_htlc_base_key: Option<PublicKey>,
 169         their_delayed_payment_base_key: Option<PublicKey>,
 170         // first is the idx of the first of the two revocation points
 171         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 172
 173         our_to_self_delay: u16,
 174         their_to_self_delay: Option<u16>,
 175
 176         old_secrets: [([u8; 32], u64); 49],
 177         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 178         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 179         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 180         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 181         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 182         /// can be used to derive the revocation key and claim the transactions.
 183         remote_commitment_txn_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 184         /// Cache used to make pruning of payment_preimages faster.
 185         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 186         /// remote transactions (ie should remain pretty small).
 187         /// Serialized to disk but should generally not be sent to Watchtowers.
 188         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 189
 190         // We store two local commitment transactions to avoid any race conditions where we may update
 191         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 192         // various monitors for one channel being out of sync, and us broadcasting a local
 193         // transaction for which we have deleted claim information on some watchtowers.
 194         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 195         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 196
 197         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 198
 199         destination_script: Script,
 200         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 201 }
 202 impl Clone for ChannelMonitor {
 203         fn clone(&self) -> Self {
 204                 ChannelMonitor {
 205                         funding_txo: self.funding_txo.clone(),
 206                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 207
 208                         key_storage: self.key_storage.clone(),
 209                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 210                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 211                         their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
 212                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 213
 214                         our_to_self_delay: self.our_to_self_delay,
 215                         their_to_self_delay: self.their_to_self_delay,
 216
 217                         old_secrets: self.old_secrets.clone(),
 218                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 219                         remote_commitment_txn_on_chain: Mutex::new((*self.remote_commitment_txn_on_chain.lock().unwrap()).clone()),
 220                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 221
 222                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 223                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 224
 225                         payment_preimages: self.payment_preimages.clone(),
 226
 227                         destination_script: self.destination_script.clone(),
 228                         secp_ctx: self.secp_ctx.clone(),
 229                 }
 230         }
 231 }
 232
 233 #[cfg(any(test, feature = "fuzztarget"))]
 234 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 235 /// underlying object
 236 impl PartialEq for ChannelMonitor {
 237         fn eq(&self, other: &Self) -> bool {
 238                 if self.funding_txo != other.funding_txo ||
 239                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 240                         self.key_storage != other.key_storage ||
 241                         self.delayed_payment_base_key != other.delayed_payment_base_key ||
 242                         self.their_htlc_base_key != other.their_htlc_base_key ||
 243                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 244                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 245                         self.our_to_self_delay != other.our_to_self_delay ||
 246                         self.their_to_self_delay != other.their_to_self_delay ||
 247                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 248                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 249                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 250                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 251                         self.payment_preimages != other.payment_preimages ||
 252                         self.destination_script != other.destination_script
 253                 {
 254                         false
 255                 } else {
 256                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 257                                 if secret != o_secret || idx != o_idx {
 258                                         return false
 259                                 }
 260                         }
 261                         let us = self.remote_commitment_txn_on_chain.lock().unwrap();
 262                         let them = other.remote_commitment_txn_on_chain.lock().unwrap();
 263                         *us == *them
 264                 }
 265         }
 266 }
 267
 268 impl ChannelMonitor {
 269         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 {
 270                 ChannelMonitor {
 271                         funding_txo: None,
 272                         commitment_transaction_number_obscure_factor: 0,
 273
 274                         key_storage: KeyStorage::PrivMode {
 275                                 revocation_base_key: revocation_base_key.clone(),
 276                                 htlc_base_key: htlc_base_key.clone(),
 277                         },
 278                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 279                         their_htlc_base_key: None,
 280                         their_delayed_payment_base_key: None,
 281                         their_cur_revocation_points: None,
 282
 283                         our_to_self_delay: our_to_self_delay,
 284                         their_to_self_delay: None,
 285
 286                         old_secrets: [([0; 32], 1 << 48); 49],
 287                         remote_claimable_outpoints: HashMap::new(),
 288                         remote_commitment_txn_on_chain: Mutex::new(HashMap::new()),
 289                         remote_hash_commitment_number: HashMap::new(),
 290
 291                         prev_local_signed_commitment_tx: None,
 292                         current_local_signed_commitment_tx: None,
 293
 294                         payment_preimages: HashMap::new(),
 295
 296                         destination_script: destination_script,
 297                         secp_ctx: Secp256k1::new(),
 298                 }
 299         }
 300
 301         #[inline]
 302         fn place_secret(idx: u64) -> u8 {
 303                 for i in 0..48 {
 304                         if idx & (1 << i) == (1 << i) {
 305                                 return i
 306                         }
 307                 }
 308                 48
 309         }
 310
 311         #[inline]
 312         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 313                 let mut res: [u8; 32] = secret;
 314                 for i in 0..bits {
 315                         let bitpos = bits - 1 - i;
 316                         if idx & (1 << bitpos) == (1 << bitpos) {
 317                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 318                                 let mut sha = Sha256::new();
 319                                 sha.input(&res);
 320                                 sha.result(&mut res);
 321                         }
 322                 }
 323                 res
 324         }
 325
 326         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 327         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 328         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 329         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 330         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 331         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 332                 let pos = ChannelMonitor::place_secret(idx);
 333                 for i in 0..pos {
 334                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 335                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 336                                 return Err(HandleError{err: "Previous secret did not match new one", action: None})
 337                         }
 338                 }
 339                 self.old_secrets[pos as usize] = (secret, idx);
 340
 341                 if let Some(new_revocation_point) = their_next_revocation_point {
 342                         match self.their_cur_revocation_points {
 343                                 Some(old_points) => {
 344                                         if old_points.0 == new_revocation_point.0 + 1 {
 345                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 346                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 347                                                 if let Some(old_second_point) = old_points.2 {
 348                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 349                                                 } else {
 350                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 351                                                 }
 352                                         } else {
 353                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 354                                         }
 355                                 },
 356                                 None => {
 357                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 358                                 }
 359                         }
 360                 }
 361
 362                 if !self.payment_preimages.is_empty() {
 363                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 364                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 365                         let min_idx = self.get_min_seen_secret();
 366                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 367
 368                         self.payment_preimages.retain(|&k, _| {
 369                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 370                                         if k == htlc.payment_hash {
 371                                                 return true
 372                                         }
 373                                 }
 374                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 375                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 376                                                 if k == htlc.payment_hash {
 377                                                         return true
 378                                                 }
 379                                         }
 380                                 }
 381                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 382                                         if *cn < min_idx {
 383                                                 return true
 384                                         }
 385                                         true
 386                                 } else { false };
 387                                 if contains {
 388                                         remote_hash_commitment_number.remove(&k);
 389                                 }
 390                                 false
 391                         });
 392                 }
 393
 394                 Ok(())
 395         }
 396
 397         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 398         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 399         /// possibly future revocation/preimage information) to claim outputs where possible.
 400         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 401         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 402                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 403                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 404                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 405                 // timeouts)
 406                 for htlc in &htlc_outputs {
 407                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 408                 }
 409                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 410         }
 411
 412         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 413         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 414         /// is important that any clones of this channel monitor (including remote clones) by kept
 415         /// up-to-date as our local commitment transaction is updated.
 416         /// Panics if set_their_to_self_delay has never been called.
 417         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)>) {
 418                 assert!(self.their_to_self_delay.is_some());
 419                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 420                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 421                         txid: signed_commitment_tx.txid(),
 422                         tx: signed_commitment_tx,
 423                         revocation_key: local_keys.revocation_key,
 424                         a_htlc_key: local_keys.a_htlc_key,
 425                         b_htlc_key: local_keys.b_htlc_key,
 426                         delayed_payment_key: local_keys.a_delayed_payment_key,
 427                         feerate_per_kw,
 428                         htlc_outputs,
 429                 });
 430         }
 431
 432         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 433         /// commitment_tx_infos which contain the payment hash have been revoked.
 434         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 435                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 436         }
 437
 438         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 439                 if self.funding_txo.is_some() {
 440                         // We should be able to compare the entire funding_txo, but in fuzztarget its trivially
 441                         // easy to collide the funding_txo hash and have a different scriptPubKey.
 442                         if other.funding_txo.is_some() && other.funding_txo.as_ref().unwrap().0 != self.funding_txo.as_ref().unwrap().0 {
 443                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", action: None});
 444                         }
 445                 } else {
 446                         self.funding_txo = other.funding_txo.take();
 447                 }
 448                 let other_min_secret = other.get_min_seen_secret();
 449                 let our_min_secret = self.get_min_seen_secret();
 450                 if our_min_secret > other_min_secret {
 451                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 452                 }
 453                 if our_min_secret >= other_min_secret {
 454                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 455                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 456                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 457                         }
 458                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 459                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 460                         }
 461                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 462                                 self.current_local_signed_commitment_tx = Some(local_tx);
 463                         }
 464                         self.payment_preimages = other.payment_preimages;
 465                 }
 466                 Ok(())
 467         }
 468
 469         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 470         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 471                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 472                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 473         }
 474
 475         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 476         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 477         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 478         /// provides slightly better privacy.
 479         /// It's the responsibility of the caller to register outpoint and script with passing the former
 480         /// value as key to add_update_monitor.
 481         pub(super) fn set_funding_info(&mut self, funding_info: (OutPoint, Script)) {
 482                 self.funding_txo = Some(funding_info);
 483         }
 484
 485         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
 486         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
 487                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 488                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
 489         }
 490
 491         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 492                 self.their_to_self_delay = Some(their_to_self_delay);
 493         }
 494
 495         pub(super) fn unset_funding_info(&mut self) {
 496                 self.funding_txo = None;
 497         }
 498
 499         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 500                 match self.funding_txo {
 501                         Some((outpoint, _)) => Some(outpoint),
 502                         None => None
 503                 }
 504         }
 505
 506         /// Serializes into a vec, with various modes for the exposed pub fns
 507         fn serialize(&self, for_local_storage: bool) -> Vec<u8> {
 508                 let mut res = Vec::new();
 509                 res.push(SERIALIZATION_VERSION);
 510                 res.push(MIN_SERIALIZATION_VERSION);
 511
 512                 match &self.funding_txo {
 513                         &Some((ref outpoint, ref script)) => {
 514                                 res.extend_from_slice(&outpoint.txid[..]);
 515                                 res.extend_from_slice(&byte_utils::be16_to_array(outpoint.index));
 516                                 res.extend_from_slice(&byte_utils::be64_to_array(script.len() as u64));
 517                                 res.extend_from_slice(&script[..]);
 518                         },
 519                         &None => {
 520                                 // We haven't even been initialized...not sure why anyone is serializing us, but
 521                                 // not much to give them.
 522                                 return res;
 523                         },
 524                 }
 525
 526                 // Set in initial Channel-object creation, so should always be set by now:
 527                 res.extend_from_slice(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor));
 528
 529                 match self.key_storage {
 530                         KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 531                                 res.push(0);
 532                                 res.extend_from_slice(&revocation_base_key[..]);
 533                                 res.extend_from_slice(&htlc_base_key[..]);
 534                         },
 535                         KeyStorage::SigsMode { .. } => unimplemented!(),
 536                 }
 537
 538                 res.extend_from_slice(&self.delayed_payment_base_key.serialize());
 539                 res.extend_from_slice(&self.their_htlc_base_key.as_ref().unwrap().serialize());
 540                 res.extend_from_slice(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize());
 541
 542                 match self.their_cur_revocation_points {
 543                         Some((idx, pubkey, second_option)) => {
 544                                 res.extend_from_slice(&byte_utils::be48_to_array(idx));
 545                                 res.extend_from_slice(&pubkey.serialize());
 546                                 match second_option {
 547                                         Some(second_pubkey) => {
 548                                                 res.extend_from_slice(&second_pubkey.serialize());
 549                                         },
 550                                         None => {
 551                                                 res.extend_from_slice(&[0; 33]);
 552                                         },
 553                                 }
 554                         },
 555                         None => {
 556                                 res.extend_from_slice(&byte_utils::be48_to_array(0));
 557                         },
 558                 }
 559
 560                 res.extend_from_slice(&byte_utils::be16_to_array(self.our_to_self_delay));
 561                 res.extend_from_slice(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()));
 562
 563                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 564                         res.extend_from_slice(secret);
 565                         res.extend_from_slice(&byte_utils::be64_to_array(*idx));
 566                 }
 567
 568                 macro_rules! serialize_htlc_in_commitment {
 569                         ($htlc_output: expr) => {
 570                                 res.push($htlc_output.offered as u8);
 571                                 res.extend_from_slice(&byte_utils::be64_to_array($htlc_output.amount_msat));
 572                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.cltv_expiry));
 573                                 res.extend_from_slice(&$htlc_output.payment_hash);
 574                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.transaction_output_index));
 575                         }
 576                 }
 577
 578                 res.extend_from_slice(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64));
 579                 for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
 580                         res.extend_from_slice(&txid[..]);
 581                         res.extend_from_slice(&byte_utils::be64_to_array(htlc_outputs.len() as u64));
 582                         for htlc_output in htlc_outputs.iter() {
 583                                 serialize_htlc_in_commitment!(htlc_output);
 584                         }
 585                 }
 586
 587                 {
 588                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
 589                         res.extend_from_slice(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64));
 590                         for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
 591                                 res.extend_from_slice(&txid[..]);
 592                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 593                         }
 594                 }
 595
 596                 if for_local_storage {
 597                         res.extend_from_slice(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64));
 598                         for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 599                                 res.extend_from_slice(payment_hash);
 600                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 601                         }
 602                 } else {
 603                         res.extend_from_slice(&byte_utils::be64_to_array(0));
 604                 }
 605
 606                 macro_rules! serialize_local_tx {
 607                         ($local_tx: expr) => {
 608                                 let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
 609                                 res.extend_from_slice(&byte_utils::be64_to_array(tx_ser.len() as u64));
 610                                 res.extend_from_slice(&tx_ser);
 611
 612                                 res.extend_from_slice(&$local_tx.revocation_key.serialize());
 613                                 res.extend_from_slice(&$local_tx.a_htlc_key.serialize());
 614                                 res.extend_from_slice(&$local_tx.b_htlc_key.serialize());
 615                                 res.extend_from_slice(&$local_tx.delayed_payment_key.serialize());
 616
 617                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.feerate_per_kw));
 618                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64));
 619                                 for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
 620                                         serialize_htlc_in_commitment!(htlc_output);
 621                                         res.extend_from_slice(&their_sig.serialize_compact(&self.secp_ctx));
 622                                         res.extend_from_slice(&our_sig.serialize_compact(&self.secp_ctx));
 623                                 }
 624                         }
 625                 }
 626
 627                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 628                         res.push(1);
 629                         serialize_local_tx!(prev_local_tx);
 630                 } else {
 631                         res.push(0);
 632                 }
 633
 634                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 635                         res.push(1);
 636                         serialize_local_tx!(cur_local_tx);
 637                 } else {
 638                         res.push(0);
 639                 }
 640
 641                 res.extend_from_slice(&byte_utils::be64_to_array(self.payment_preimages.len() as u64));
 642                 for payment_preimage in self.payment_preimages.values() {
 643                         res.extend_from_slice(payment_preimage);
 644                 }
 645
 646                 res.extend_from_slice(&byte_utils::be64_to_array(self.destination_script.len() as u64));
 647                 res.extend_from_slice(&self.destination_script[..]);
 648
 649                 res
 650         }
 651
 652         /// Encodes this monitor into a byte array, suitable for writing to disk.
 653         pub fn serialize_for_disk(&self) -> Vec<u8> {
 654                 self.serialize(true)
 655         }
 656
 657         /// Encodes this monitor into a byte array, suitable for sending to a remote watchtower
 658         pub fn serialize_for_watchtower(&self) -> Vec<u8> {
 659                 self.serialize(false)
 660         }
 661
 662         /// Attempts to decode a serialized monitor
 663         pub fn deserialize(data: &[u8]) -> Option<Self> {
 664                 let mut read_pos = 0;
 665                 macro_rules! read_bytes {
 666                         ($byte_count: expr) => {
 667                                 {
 668                                         if ($byte_count as usize) > data.len() - read_pos {
 669                                                 return None;
 670                                         }
 671                                         read_pos += $byte_count as usize;
 672                                         &data[read_pos - $byte_count as usize..read_pos]
 673                                 }
 674                         }
 675                 }
 676
 677                 let secp_ctx = Secp256k1::new();
 678                 macro_rules! unwrap_obj {
 679                         ($key: expr) => {
 680                                 match $key {
 681                                         Ok(res) => res,
 682                                         Err(_) => return None,
 683                                 }
 684                         }
 685                 }
 686
 687                 let _ver = read_bytes!(1)[0];
 688                 let min_ver = read_bytes!(1)[0];
 689                 if min_ver > SERIALIZATION_VERSION {
 690                         return None;
 691                 }
 692
 693                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
 694                 // barely-init'd ChannelMonitors that we can't do anything with.
 695                 let outpoint = OutPoint {
 696                         txid: Sha256dHash::from(read_bytes!(32)),
 697                         index: byte_utils::slice_to_be16(read_bytes!(2)),
 698                 };
 699                 let script_len = byte_utils::slice_to_be64(read_bytes!(8));
 700                 let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
 701                 let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
 702
 703                 let key_storage = match read_bytes!(1)[0] {
 704                         0 => {
 705                                 KeyStorage::PrivMode {
 706                                         revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 707                                         htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 708                                 }
 709                         },
 710                         _ => return None,
 711                 };
 712
 713                 let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 714                 let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 715                 let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 716
 717                 let their_cur_revocation_points = {
 718                         let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
 719                         if first_idx == 0 {
 720                                 None
 721                         } else {
 722                                 let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 723                                 let second_point_slice = read_bytes!(33);
 724                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
 725                                         Some((first_idx, first_point, None))
 726                                 } else {
 727                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
 728                                 }
 729                         }
 730                 };
 731
 732                 let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
 733                 let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
 734
 735                 let mut old_secrets = [([0; 32], 1 << 48); 49];
 736                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
 737                         secret.copy_from_slice(read_bytes!(32));
 738                         *idx = byte_utils::slice_to_be64(read_bytes!(8));
 739                 }
 740
 741                 macro_rules! read_htlc_in_commitment {
 742                         () => {
 743                                 {
 744                                         let offered = match read_bytes!(1)[0] {
 745                                                 0 => false, 1 => true,
 746                                                 _ => return None,
 747                                         };
 748                                         let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
 749                                         let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
 750                                         let mut payment_hash = [0; 32];
 751                                         payment_hash[..].copy_from_slice(read_bytes!(32));
 752                                         let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
 753
 754                                         HTLCOutputInCommitment {
 755                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
 756                                         }
 757                                 }
 758                         }
 759                 }
 760
 761                 let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
 762                 if remote_claimable_outpoints_len > data.len() as u64 / 64 { return None; }
 763                 let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
 764                 for _ in 0..remote_claimable_outpoints_len {
 765                         let txid = Sha256dHash::from(read_bytes!(32));
 766                         let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
 767                         if outputs_count > data.len() as u64 / 32 { return None; }
 768                         let mut outputs = Vec::with_capacity(outputs_count as usize);
 769                         for _ in 0..outputs_count {
 770                                 outputs.push(read_htlc_in_commitment!());
 771                         }
 772                         if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
 773                                 return None;
 774                         }
 775                 }
 776
 777                 let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
 778                 if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return None; }
 779                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
 780                 for _ in 0..remote_commitment_txn_on_chain_len {
 781                         let txid = Sha256dHash::from(read_bytes!(32));
 782                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 783                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
 784                                 return None;
 785                         }
 786                 }
 787
 788                 let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
 789                 if remote_hash_commitment_number_len > data.len() as u64 / 32 { return None; }
 790                 let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
 791                 for _ in 0..remote_hash_commitment_number_len {
 792                         let mut txid = [0; 32];
 793                         txid[..].copy_from_slice(read_bytes!(32));
 794                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 795                         if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
 796                                 return None;
 797                         }
 798                 }
 799
 800                 macro_rules! read_local_tx {
 801                         () => {
 802                                 {
 803                                         let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
 804                                         let tx_ser = read_bytes!(tx_len);
 805                                         let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
 806                                         if serialize::serialize(&tx).unwrap() != tx_ser {
 807                                                 // We check that the tx re-serializes to the same form to ensure there is
 808                                                 // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
 809                                                 // all that well.
 810                                                 return None;
 811                                         }
 812
 813                                         let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 814                                         let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 815                                         let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 816                                         let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 817                                         let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
 818
 819                                         let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
 820                                         if htlc_outputs_len > data.len() as u64 / 128 { return None; }
 821                                         let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
 822                                         for _ in 0..htlc_outputs_len {
 823                                                 htlc_outputs.push((read_htlc_in_commitment!(),
 824                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
 825                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
 826                                         }
 827
 828                                         LocalSignedTx {
 829                                                 txid: tx.txid(),
 830                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
 831                                         }
 832                                 }
 833                         }
 834                 }
 835
 836                 let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
 837                         0 => None,
 838                         1 => {
 839                                 Some(read_local_tx!())
 840                         },
 841                         _ => return None,
 842                 };
 843
 844                 let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
 845                         0 => None,
 846                         1 => {
 847                                 Some(read_local_tx!())
 848                         },
 849                         _ => return None,
 850                 };
 851
 852                 let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
 853                 if payment_preimages_len > data.len() as u64 / 32 { return None; }
 854                 let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
 855                 let mut sha = Sha256::new();
 856                 for _ in 0..payment_preimages_len {
 857                         let mut preimage = [0; 32];
 858                         preimage[..].copy_from_slice(read_bytes!(32));
 859                         sha.reset();
 860                         sha.input(&preimage);
 861                         let mut hash = [0; 32];
 862                         sha.result(&mut hash);
 863                         if let Some(_) = payment_preimages.insert(hash, preimage) {
 864                                 return None;
 865                         }
 866                 }
 867
 868                 let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
 869                 let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
 870
 871                 Some(ChannelMonitor {
 872                         funding_txo,
 873                         commitment_transaction_number_obscure_factor,
 874
 875                         key_storage,
 876                         delayed_payment_base_key,
 877                         their_htlc_base_key,
 878                         their_delayed_payment_base_key,
 879                         their_cur_revocation_points,
 880
 881                         our_to_self_delay,
 882                         their_to_self_delay,
 883
 884                         old_secrets,
 885                         remote_claimable_outpoints,
 886                         remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
 887                         remote_hash_commitment_number,
 888
 889                         prev_local_signed_commitment_tx,
 890                         current_local_signed_commitment_tx,
 891
 892                         payment_preimages,
 893
 894                         destination_script,
 895                         secp_ctx,
 896                 })
 897         }
 898
 899         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 900         //we want to leave out (eg funding_txo, etc).
 901
 902         /// Can only fail if idx is < get_min_seen_secret
 903         pub fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 904                 for i in 0..self.old_secrets.len() {
 905                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 906                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 907                         }
 908                 }
 909                 assert!(idx < self.get_min_seen_secret());
 910                 Err(HandleError{err: "idx too low", action: None})
 911         }
 912
 913         pub fn get_min_seen_secret(&self) -> u64 {
 914                 //TODO This can be optimized?
 915                 let mut min = 1 << 48;
 916                 for &(_, idx) in self.old_secrets.iter() {
 917                         if idx < min {
 918                                 min = idx;
 919                         }
 920                 }
 921                 min
 922         }
 923
 924         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 925         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 926         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 927         /// HTLC-Success/HTLC-Timeout transactions.
 928         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
 929                 // Most secp and related errors trying to create keys means we have no hope of constructing
 930                 // a spend transaction...so we return no transactions to broadcast
 931                 let mut txn_to_broadcast = Vec::new();
 932                 let mut watch_outputs = Vec::new();
 933
 934                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 935                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 936
 937                 macro_rules! ignore_error {
 938                         ( $thing : expr ) => {
 939                                 match $thing {
 940                                         Ok(a) => a,
 941                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs))
 942                                 }
 943                         };
 944                 }
 945
 946                 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);
 947                 if commitment_number >= self.get_min_seen_secret() {
 948                         let secret = self.get_secret(commitment_number).unwrap();
 949                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 950                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 951                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 952                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 953                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 954                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 955                                 },
 956                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 957                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 958                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 959                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 960                                 },
 961                         };
 962                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.delayed_payment_base_key));
 963                         let a_htlc_key = match self.their_htlc_base_key {
 964                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 965                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_htlc_base_key)),
 966                         };
 967
 968                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 969                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 970
 971                         let mut total_value = 0;
 972                         let mut values = Vec::new();
 973                         let mut inputs = Vec::new();
 974                         let mut htlc_idxs = Vec::new();
 975
 976                         for (idx, outp) in tx.output.iter().enumerate() {
 977                                 if outp.script_pubkey == revokeable_p2wsh {
 978                                         inputs.push(TxIn {
 979                                                 previous_output: BitcoinOutPoint {
 980                                                         txid: commitment_txid,
 981                                                         vout: idx as u32,
 982                                                 },
 983                                                 script_sig: Script::new(),
 984                                                 sequence: 0xfffffffd,
 985                                                 witness: Vec::new(),
 986                                         });
 987                                         htlc_idxs.push(None);
 988                                         values.push(outp.value);
 989                                         total_value += outp.value;
 990                                         break; // There can only be one of these
 991                                 }
 992                         }
 993
 994                         macro_rules! sign_input {
 995                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 996                                         {
 997                                                 let (sig, redeemscript) = match self.key_storage {
 998                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
 999                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
1000                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
1001                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
1002                                                                 };
1003                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
1004                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1005                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
1006                                                         },
1007                                                         KeyStorage::SigsMode { .. } => {
1008                                                                 unimplemented!();
1009                                                         }
1010                                                 };
1011                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1012                                                 $input.witness[0].push(SigHashType::All as u8);
1013                                                 if $htlc_idx.is_none() {
1014                                                         $input.witness.push(vec!(1));
1015                                                 } else {
1016                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
1017                                                 }
1018                                                 $input.witness.push(redeemscript.into_bytes());
1019                                         }
1020                                 }
1021                         }
1022
1023                         if let Some(per_commitment_data) = per_commitment_option {
1024                                 inputs.reserve_exact(per_commitment_data.len());
1025
1026                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
1027                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1028                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
1029                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1030                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1031                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1032                                         }
1033                                         let input = TxIn {
1034                                                 previous_output: BitcoinOutPoint {
1035                                                         txid: commitment_txid,
1036                                                         vout: htlc.transaction_output_index,
1037                                                 },
1038                                                 script_sig: Script::new(),
1039                                                 sequence: 0xfffffffd,
1040                                                 witness: Vec::new(),
1041                                         };
1042                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1043                                                 inputs.push(input);
1044                                                 htlc_idxs.push(Some(idx));
1045                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
1046                                                 total_value += htlc.amount_msat / 1000;
1047                                         } else {
1048                                                 let mut single_htlc_tx = Transaction {
1049                                                         version: 2,
1050                                                         lock_time: 0,
1051                                                         input: vec![input],
1052                                                         output: vec!(TxOut {
1053                                                                 script_pubkey: self.destination_script.clone(),
1054                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1055                                                         }),
1056                                                 };
1057                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1058                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
1059                                                 txn_to_broadcast.push(single_htlc_tx); // TODO: This is not yet tested in ChannelManager!
1060                                         }
1061                                 }
1062                         }
1063
1064                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours
1065                                 // We're definitely a remote commitment transaction!
1066                                 watch_outputs.append(&mut tx.output.clone());
1067                                 self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1068                         }
1069                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
1070
1071                         let outputs = vec!(TxOut {
1072                                 script_pubkey: self.destination_script.clone(),
1073                                 value: total_value, //TODO: - fee
1074                         });
1075                         let mut spend_tx = Transaction {
1076                                 version: 2,
1077                                 lock_time: 0,
1078                                 input: inputs,
1079                                 output: outputs,
1080                         };
1081
1082                         let mut values_drain = values.drain(..);
1083                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1084
1085                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
1086                                 let value = values_drain.next().unwrap();
1087                                 sign_input!(sighash_parts, input, htlc_idx, value);
1088                         }
1089
1090                         txn_to_broadcast.push(spend_tx);
1091                 } else if let Some(per_commitment_data) = per_commitment_option {
1092                         // While this isn't useful yet, there is a potential race where if a counterparty
1093                         // revokes a state at the same time as the commitment transaction for that state is
1094                         // confirmed, and the watchtower receives the block before the user, the user could
1095                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
1096                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1097                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
1098                         // insert it here.
1099                         watch_outputs.append(&mut tx.output.clone());
1100                         self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1101
1102                         if let Some(revocation_points) = self.their_cur_revocation_points {
1103                                 let revocation_point_option =
1104                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1105                                         else if let Some(point) = revocation_points.2.as_ref() {
1106                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1107                                         } else { None };
1108                                 if let Some(revocation_point) = revocation_point_option {
1109                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
1110                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
1111                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1112                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
1113                                                 },
1114                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
1115                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
1116                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1117                                                 },
1118                                         };
1119                                         let a_htlc_key = match self.their_htlc_base_key {
1120                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
1121                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1122                                         };
1123
1124                                         let mut total_value = 0;
1125                                         let mut values = Vec::new();
1126                                         let mut inputs = Vec::new();
1127
1128                                         macro_rules! sign_input {
1129                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
1130                                                         {
1131                                                                 let (sig, redeemscript) = match self.key_storage {
1132                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
1133                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
1134                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1135                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
1136                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
1137                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
1138                                                                         },
1139                                                                         KeyStorage::SigsMode { .. } => {
1140                                                                                 unimplemented!();
1141                                                                         }
1142                                                                 };
1143                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1144                                                                 $input.witness[0].push(SigHashType::All as u8);
1145                                                                 $input.witness.push($preimage);
1146                                                                 $input.witness.push(redeemscript.into_bytes());
1147                                                         }
1148                                                 }
1149                                         }
1150
1151                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
1152                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1153                                                         let input = TxIn {
1154                                                                 previous_output: BitcoinOutPoint {
1155                                                                         txid: commitment_txid,
1156                                                                         vout: htlc.transaction_output_index,
1157                                                                 },
1158                                                                 script_sig: Script::new(),
1159                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
1160                                                                 witness: Vec::new(),
1161                                                         };
1162                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1163                                                                 inputs.push(input);
1164                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
1165                                                                 total_value += htlc.amount_msat / 1000;
1166                                                         } else {
1167                                                                 let mut single_htlc_tx = Transaction {
1168                                                                         version: 2,
1169                                                                         lock_time: 0,
1170                                                                         input: vec![input],
1171                                                                         output: vec!(TxOut {
1172                                                                                 script_pubkey: self.destination_script.clone(),
1173                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1174                                                                         }),
1175                                                                 };
1176                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1177                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
1178                                                                 txn_to_broadcast.push(single_htlc_tx);
1179                                                         }
1180                                                 }
1181                                         }
1182
1183                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
1184
1185                                         let outputs = vec!(TxOut {
1186                                                 script_pubkey: self.destination_script.clone(),
1187                                                 value: total_value, //TODO: - fee
1188                                         });
1189                                         let mut spend_tx = Transaction {
1190                                                 version: 2,
1191                                                 lock_time: 0,
1192                                                 input: inputs,
1193                                                 output: outputs,
1194                                         };
1195
1196                                         let mut values_drain = values.drain(..);
1197                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1198
1199                                         for input in spend_tx.input.iter_mut() {
1200                                                 let value = values_drain.next().unwrap();
1201                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
1202                                         }
1203
1204                                         txn_to_broadcast.push(spend_tx);
1205                                 }
1206                         }
1207                 }
1208
1209                 (txn_to_broadcast, (commitment_txid, watch_outputs))
1210         }
1211
1212         /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
1213         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Vec<Transaction> {
1214                 let mut txn_to_broadcast = Vec::new();
1215
1216                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1217
1218                 macro_rules! ignore_error {
1219                         ( $thing : expr ) => {
1220                                 match $thing {
1221                                         Ok(a) => a,
1222                                         Err(_) => return txn_to_broadcast
1223                                 }
1224                         };
1225                 }
1226
1227                 let secret = self.get_secret(commitment_number).unwrap();
1228                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
1229                 let revocation_pubkey = match self.key_storage {
1230                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1231                                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1232                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1233                         },
1234                         KeyStorage::SigsMode { ref revocation_base_key, .. } => {
1235                                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1236                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
1237                         },
1238                 };
1239                 let delayed_key = match self.their_delayed_payment_base_key {
1240                         None => return txn_to_broadcast,
1241                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &their_delayed_payment_base_key)),
1242                 };
1243                 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
1244                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1245
1246                 let mut inputs = Vec::new();
1247                 let mut amount = 0;
1248
1249                 if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
1250                         inputs.push(TxIn {
1251                                 previous_output: BitcoinOutPoint {
1252                                         txid: htlc_txid,
1253                                         vout: 0,
1254                                 },
1255                                 script_sig: Script::new(),
1256                                 sequence: 0xfffffffd,
1257                                 witness: Vec::new(),
1258                         });
1259                         amount = tx.output[0].value;
1260                 }
1261
1262                 if !inputs.is_empty() {
1263                         let outputs = vec!(TxOut {
1264                                 script_pubkey: self.destination_script.clone(),
1265                                 value: amount, //TODO: - fee
1266                         });
1267
1268                         let mut spend_tx = Transaction {
1269                                 version: 2,
1270                                 lock_time: 0,
1271                                 input: inputs,
1272                                 output: outputs,
1273                         };
1274
1275
1276                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1277
1278                         let sig = match self.key_storage {
1279                                 KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1280                                         let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]));
1281                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1282                                         self.secp_ctx.sign(&sighash, &revocation_key)
1283                                 }
1284                                 KeyStorage::SigsMode { .. } => {
1285                                         unimplemented!();
1286                                 }
1287                         };
1288                         spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1289                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1290                         spend_tx.input[0].witness.push(vec!(1));
1291                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1292
1293                         txn_to_broadcast.push(spend_tx);
1294                 }
1295                 txn_to_broadcast
1296         }
1297
1298         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
1299                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1300
1301                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
1302                         if htlc.offered {
1303                                 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);
1304
1305                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1306
1307                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1308                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1309                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1310                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1311
1312                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1313                                 htlc_timeout_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
1314
1315                                 res.push(htlc_timeout_tx);
1316                         } else {
1317                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1318                                         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);
1319
1320                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1321
1322                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1323                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1324                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1325                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1326
1327                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
1328                                         htlc_success_tx.input[0].witness.push(chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &local_tx.a_htlc_key, &local_tx.b_htlc_key, &local_tx.revocation_key).into_bytes());
1329
1330                                         res.push(htlc_success_tx);
1331                                 }
1332                         }
1333                 }
1334
1335                 res
1336         }
1337
1338         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1339         /// revoked using data in local_claimable_outpoints.
1340         /// Should not be used if check_spend_revoked_transaction succeeds.
1341         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
1342                 let commitment_txid = tx.txid();
1343                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1344                         if local_tx.txid == commitment_txid {
1345                                 return self.broadcast_by_local_state(local_tx);
1346                         }
1347                 }
1348                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1349                         if local_tx.txid == commitment_txid {
1350                                 return self.broadcast_by_local_state(local_tx);
1351                         }
1352                 }
1353                 Vec::new()
1354         }
1355
1356         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
1357                 let mut watch_outputs = Vec::new();
1358                 for tx in txn_matched {
1359                         let mut txn: Vec<Transaction> = Vec::new();
1360                         for txin in tx.input.iter() {
1361                                 if self.funding_txo.is_none() || (txin.previous_output.txid == self.funding_txo.as_ref().unwrap().0.txid && txin.previous_output.vout == self.funding_txo.as_ref().unwrap().0.index as u32) {
1362                                         let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
1363                                         txn = remote_txn;
1364                                         if !new_outputs.1.is_empty() {
1365                                                 watch_outputs.push(new_outputs);
1366                                         }
1367                                         if txn.is_empty() {
1368                                                 txn = self.check_spend_local_transaction(tx, height);
1369                                         }
1370                                 } else {
1371                                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
1372                                         for commitment_number in remote_commitment_txn_on_chain.get(&txin.previous_output.txid) {
1373                                                 txn =  self.check_spend_remote_htlc(tx, *commitment_number);
1374                                         }
1375                                 }
1376                                 for tx in txn.iter() {
1377                                         broadcaster.broadcast_transaction(tx);
1378                                 }
1379                         }
1380                 }
1381                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1382                         let mut needs_broadcast = false;
1383                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1384                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1385                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1386                                                 needs_broadcast = true;
1387                                         }
1388                                 }
1389                         }
1390
1391                         if needs_broadcast {
1392                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1393                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
1394                                         broadcaster.broadcast_transaction(&tx);
1395                                 }
1396                         }
1397                 }
1398                 watch_outputs
1399         }
1400
1401         pub fn would_broadcast_at_height(&self, height: u32) -> bool {
1402                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1403                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1404                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1405                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1406                                                 return true;
1407                                         }
1408                                 }
1409                         }
1410                 }
1411                 false
1412         }
1413 }
1414
1415 #[cfg(test)]
1416 mod tests {
1417         use bitcoin::blockdata::script::Script;
1418         use bitcoin::blockdata::transaction::Transaction;
1419         use crypto::digest::Digest;
1420         use hex;
1421         use ln::channelmonitor::ChannelMonitor;
1422         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
1423         use util::sha2::Sha256;
1424         use secp256k1::key::{SecretKey,PublicKey};
1425         use secp256k1::{Secp256k1, Signature};
1426         use rand::{thread_rng,Rng};
1427
1428         #[test]
1429         fn test_per_commitment_storage() {
1430                 // Test vectors from BOLT 3:
1431                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1432                 let mut monitor: ChannelMonitor;
1433                 let secp_ctx = Secp256k1::new();
1434
1435                 macro_rules! test_secrets {
1436                         () => {
1437                                 let mut idx = 281474976710655;
1438                                 for secret in secrets.iter() {
1439                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1440                                         idx -= 1;
1441                                 }
1442                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1443                                 assert!(monitor.get_secret(idx).is_err());
1444                         };
1445                 }
1446
1447                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1448
1449                 {
1450                         // insert_secret correct sequence
1451                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1452                         secrets.clear();
1453
1454                         secrets.push([0; 32]);
1455                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1456                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1457                         test_secrets!();
1458
1459                         secrets.push([0; 32]);
1460                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1461                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1462                         test_secrets!();
1463
1464                         secrets.push([0; 32]);
1465                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1466                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1467                         test_secrets!();
1468
1469                         secrets.push([0; 32]);
1470                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1471                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1472                         test_secrets!();
1473
1474                         secrets.push([0; 32]);
1475                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1476                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1477                         test_secrets!();
1478
1479                         secrets.push([0; 32]);
1480                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1481                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1482                         test_secrets!();
1483
1484                         secrets.push([0; 32]);
1485                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1486                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1487                         test_secrets!();
1488
1489                         secrets.push([0; 32]);
1490                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1491                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
1492                         test_secrets!();
1493                 }
1494
1495                 {
1496                         // insert_secret #1 incorrect
1497                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1498                         secrets.clear();
1499
1500                         secrets.push([0; 32]);
1501                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1502                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1503                         test_secrets!();
1504
1505                         secrets.push([0; 32]);
1506                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1507                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
1508                                         "Previous secret did not match new one");
1509                 }
1510
1511                 {
1512                         // insert_secret #2 incorrect (#1 derived from incorrect)
1513                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1514                         secrets.clear();
1515
1516                         secrets.push([0; 32]);
1517                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1518                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1519                         test_secrets!();
1520
1521                         secrets.push([0; 32]);
1522                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1523                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1524                         test_secrets!();
1525
1526                         secrets.push([0; 32]);
1527                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1528                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1529                         test_secrets!();
1530
1531                         secrets.push([0; 32]);
1532                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1533                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1534                                         "Previous secret did not match new one");
1535                 }
1536
1537                 {
1538                         // insert_secret #3 incorrect
1539                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1540                         secrets.clear();
1541
1542                         secrets.push([0; 32]);
1543                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1544                         monitor.provide_secret(281474976710655, 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::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1549                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1550                         test_secrets!();
1551
1552                         secrets.push([0; 32]);
1553                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1554                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1555                         test_secrets!();
1556
1557                         secrets.push([0; 32]);
1558                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1559                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1560                                         "Previous secret did not match new one");
1561                 }
1562
1563                 {
1564                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1565                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1566                         secrets.clear();
1567
1568                         secrets.push([0; 32]);
1569                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1570                         monitor.provide_secret(281474976710655, 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::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1575                         monitor.provide_secret(281474976710654, 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::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1580                         monitor.provide_secret(281474976710653, 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::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1585                         monitor.provide_secret(281474976710652, 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::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1590                         monitor.provide_secret(281474976710651, 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::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1595                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1596                         test_secrets!();
1597
1598                         secrets.push([0; 32]);
1599                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1600                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1601                         test_secrets!();
1602
1603                         secrets.push([0; 32]);
1604                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1605                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1606                                         "Previous secret did not match new one");
1607                 }
1608
1609                 {
1610                         // insert_secret #5 incorrect
1611                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1612                         secrets.clear();
1613
1614                         secrets.push([0; 32]);
1615                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1616                         monitor.provide_secret(281474976710655, 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::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1621                         monitor.provide_secret(281474976710654, 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::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1626                         monitor.provide_secret(281474976710653, 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::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1631                         monitor.provide_secret(281474976710652, 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::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1636                         monitor.provide_secret(281474976710651, 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::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1641                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1642                                         "Previous secret did not match new one");
1643                 }
1644
1645                 {
1646                         // insert_secret #6 incorrect (5 derived from incorrect)
1647                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1648                         secrets.clear();
1649
1650                         secrets.push([0; 32]);
1651                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1652                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1653                         test_secrets!();
1654
1655                         secrets.push([0; 32]);
1656                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1657                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1658                         test_secrets!();
1659
1660                         secrets.push([0; 32]);
1661                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1662                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1663                         test_secrets!();
1664
1665                         secrets.push([0; 32]);
1666                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1667                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1668                         test_secrets!();
1669
1670                         secrets.push([0; 32]);
1671                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1672                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1673                         test_secrets!();
1674
1675                         secrets.push([0; 32]);
1676                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1677                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1678                         test_secrets!();
1679
1680                         secrets.push([0; 32]);
1681                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1682                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1683                         test_secrets!();
1684
1685                         secrets.push([0; 32]);
1686                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1687                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1688                                         "Previous secret did not match new one");
1689                 }
1690
1691                 {
1692                         // insert_secret #7 incorrect
1693                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1694                         secrets.clear();
1695
1696                         secrets.push([0; 32]);
1697                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1698                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1699                         test_secrets!();
1700
1701                         secrets.push([0; 32]);
1702                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1703                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1704                         test_secrets!();
1705
1706                         secrets.push([0; 32]);
1707                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1708                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1709                         test_secrets!();
1710
1711                         secrets.push([0; 32]);
1712                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1713                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1714                         test_secrets!();
1715
1716                         secrets.push([0; 32]);
1717                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1718                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1719                         test_secrets!();
1720
1721                         secrets.push([0; 32]);
1722                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1723                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1724                         test_secrets!();
1725
1726                         secrets.push([0; 32]);
1727                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1728                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1729                         test_secrets!();
1730
1731                         secrets.push([0; 32]);
1732                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1733                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1734                                         "Previous secret did not match new one");
1735                 }
1736
1737                 {
1738                         // insert_secret #8 incorrect
1739                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1740                         secrets.clear();
1741
1742                         secrets.push([0; 32]);
1743                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1744                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1745                         test_secrets!();
1746
1747                         secrets.push([0; 32]);
1748                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1749                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1750                         test_secrets!();
1751
1752                         secrets.push([0; 32]);
1753                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1754                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1755                         test_secrets!();
1756
1757                         secrets.push([0; 32]);
1758                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1759                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1760                         test_secrets!();
1761
1762                         secrets.push([0; 32]);
1763                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1764                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1765                         test_secrets!();
1766
1767                         secrets.push([0; 32]);
1768                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1769                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1770                         test_secrets!();
1771
1772                         secrets.push([0; 32]);
1773                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1774                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1775                         test_secrets!();
1776
1777                         secrets.push([0; 32]);
1778                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1779                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1780                                         "Previous secret did not match new one");
1781                 }
1782         }
1783
1784         #[test]
1785         fn test_prune_preimages() {
1786                 let secp_ctx = Secp256k1::new();
1787                 let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap();
1788
1789                 macro_rules! dummy_keys {
1790                         () => {
1791                                 {
1792                                         let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1793                                         TxCreationKeys {
1794                                                 per_commitment_point: dummy_key.clone(),
1795                                                 revocation_key: dummy_key.clone(),
1796                                                 a_htlc_key: dummy_key.clone(),
1797                                                 b_htlc_key: dummy_key.clone(),
1798                                                 a_delayed_payment_key: dummy_key.clone(),
1799                                                 b_payment_key: dummy_key.clone(),
1800                                         }
1801                                 }
1802                         }
1803                 }
1804                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
1805
1806                 let mut preimages = Vec::new();
1807                 {
1808                         let mut rng  = thread_rng();
1809                         for _ in 0..20 {
1810                                 let mut preimage = [0; 32];
1811                                 rng.fill_bytes(&mut preimage);
1812                                 let mut sha = Sha256::new();
1813                                 sha.input(&preimage);
1814                                 let mut hash = [0; 32];
1815                                 sha.result(&mut hash);
1816                                 preimages.push((preimage, hash));
1817                         }
1818                 }
1819
1820                 macro_rules! preimages_slice_to_htlc_outputs {
1821                         ($preimages_slice: expr) => {
1822                                 {
1823                                         let mut res = Vec::new();
1824                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
1825                                                 res.push(HTLCOutputInCommitment {
1826                                                         offered: true,
1827                                                         amount_msat: 0,
1828                                                         cltv_expiry: 0,
1829                                                         payment_hash: preimage.1.clone(),
1830                                                         transaction_output_index: idx as u32,
1831                                                 });
1832                                         }
1833                                         res
1834                                 }
1835                         }
1836                 }
1837                 macro_rules! preimages_to_local_htlcs {
1838                         ($preimages_slice: expr) => {
1839                                 {
1840                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
1841                                         let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect();
1842                                         res
1843                                 }
1844                         }
1845                 }
1846
1847                 macro_rules! test_preimages_exist {
1848                         ($preimages_slice: expr, $monitor: expr) => {
1849                                 for preimage in $preimages_slice {
1850                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
1851                                 }
1852                         }
1853                 }
1854
1855                 // Prune with one old state and a local commitment tx holding a few overlaps with the
1856                 // old state.
1857                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1858                 let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &delayed_payment_base_key, &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1859                 monitor.set_their_to_self_delay(10);
1860
1861                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
1862                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655);
1863                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654);
1864                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653);
1865                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652);
1866                 for &(ref preimage, ref hash) in preimages.iter() {
1867                         monitor.provide_payment_preimage(hash, preimage);
1868                 }
1869
1870                 // Now provide a secret, pruning preimages 10-15
1871                 let mut secret = [0; 32];
1872                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1873                 monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1874                 assert_eq!(monitor.payment_preimages.len(), 15);
1875                 test_preimages_exist!(&preimages[0..10], monitor);
1876                 test_preimages_exist!(&preimages[15..20], monitor);
1877
1878                 // Now provide a further secret, pruning preimages 15-17
1879                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1880                 monitor.provide_secret(281474976710654, secret.clone(), None).unwrap();
1881                 assert_eq!(monitor.payment_preimages.len(), 13);
1882                 test_preimages_exist!(&preimages[0..10], monitor);
1883                 test_preimages_exist!(&preimages[17..20], monitor);
1884
1885                 // Now update local commitment tx info, pruning only element 18 as we still care about the
1886                 // previous commitment tx's preimages too
1887                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
1888                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1889                 monitor.provide_secret(281474976710653, secret.clone(), None).unwrap();
1890                 assert_eq!(monitor.payment_preimages.len(), 12);
1891                 test_preimages_exist!(&preimages[0..10], monitor);
1892                 test_preimages_exist!(&preimages[18..20], monitor);
1893
1894                 // But if we do it again, we'll prune 5-10
1895                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
1896                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1897                 monitor.provide_secret(281474976710652, secret.clone(), None).unwrap();
1898                 assert_eq!(monitor.payment_preimages.len(), 5);
1899                 test_preimages_exist!(&preimages[0..5], monitor);
1900         }
1901
1902         // Further testing is done in the ChannelManager integration tests.
1903 }