_ 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         #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
  67         pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  68         #[cfg(not(test))]
  69         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  70         chain_monitor: Arc<ChainWatchInterface>,
  71         broadcaster: Arc<BroadcasterInterface>
  72 }
  73
  74 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
  75         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
  76                 let monitors = self.monitors.lock().unwrap();
  77                 for monitor in monitors.values() {
  78                         let txn_outputs = monitor.block_connected(txn_matched, height, &*self.broadcaster);
  79                         for (ref txid, ref outputs) in txn_outputs {
  80                                 for (idx, output) in outputs.iter().enumerate() {
  81                                         self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
  82                                 }
  83                         }
  84                 }
  85         }
  86
  87         fn block_disconnected(&self, _: &BlockHeader) { }
  88 }
  89
  90 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
  91         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
  92                 let res = Arc::new(SimpleManyChannelMonitor {
  93                         monitors: Mutex::new(HashMap::new()),
  94                         chain_monitor,
  95                         broadcaster
  96                 });
  97                 let weak_res = Arc::downgrade(&res);
  98                 res.chain_monitor.register_listener(weak_res);
  99                 res
 100         }
 101
 102         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
 103                 let mut monitors = self.monitors.lock().unwrap();
 104                 match monitors.get_mut(&key) {
 105                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
 106                         None => {}
 107                 };
 108                 match &monitor.funding_txo {
 109                         &None => self.chain_monitor.watch_all_txn(),
 110                         &Some((ref outpoint, ref script)) => {
 111                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
 112                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
 113                         },
 114                 }
 115                 monitors.insert(key, monitor);
 116                 Ok(())
 117         }
 118 }
 119
 120 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 121         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 122                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 123                         Ok(_) => Ok(()),
 124                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 125                 }
 126         }
 127 }
 128
 129 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 130 /// instead claiming it in its own individual transaction.
 131 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 132 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 133 /// HTLC-Success transaction.
 134 const CLTV_CLAIM_BUFFER: u32 = 6;
 135
 136 #[derive(Clone, PartialEq)]
 137 enum KeyStorage {
 138         PrivMode {
 139                 revocation_base_key: SecretKey,
 140                 htlc_base_key: SecretKey,
 141         },
 142         SigsMode {
 143                 revocation_base_key: PublicKey,
 144                 htlc_base_key: PublicKey,
 145                 sigs: HashMap<Sha256dHash, Signature>,
 146         }
 147 }
 148
 149 #[derive(Clone, PartialEq)]
 150 struct LocalSignedTx {
 151         /// txid of the transaction in tx, just used to make comparison faster
 152         txid: Sha256dHash,
 153         tx: Transaction,
 154         revocation_key: PublicKey,
 155         a_htlc_key: PublicKey,
 156         b_htlc_key: PublicKey,
 157         delayed_payment_key: PublicKey,
 158         feerate_per_kw: u64,
 159         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 160 }
 161
 162 const SERIALIZATION_VERSION: u8 = 1;
 163 const MIN_SERIALIZATION_VERSION: u8 = 1;
 164
 165 pub struct ChannelMonitor {
 166         funding_txo: Option<(OutPoint, Script)>,
 167         commitment_transaction_number_obscure_factor: u64,
 168
 169         key_storage: KeyStorage,
 170         delayed_payment_base_key: PublicKey,
 171         their_htlc_base_key: Option<PublicKey>,
 172         their_delayed_payment_base_key: Option<PublicKey>,
 173         // first is the idx of the first of the two revocation points
 174         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 175
 176         our_to_self_delay: u16,
 177         their_to_self_delay: Option<u16>,
 178
 179         old_secrets: [([u8; 32], u64); 49],
 180         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 181         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 182         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 183         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 184         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 185         /// can be used to derive the revocation key and claim the transactions.
 186         remote_commitment_txn_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 187         /// Cache used to make pruning of payment_preimages faster.
 188         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 189         /// remote transactions (ie should remain pretty small).
 190         /// Serialized to disk but should generally not be sent to Watchtowers.
 191         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 192
 193         // We store two local commitment transactions to avoid any race conditions where we may update
 194         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 195         // various monitors for one channel being out of sync, and us broadcasting a local
 196         // transaction for which we have deleted claim information on some watchtowers.
 197         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 198         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 199
 200         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 201
 202         destination_script: Script,
 203         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 204 }
 205 impl Clone for ChannelMonitor {
 206         fn clone(&self) -> Self {
 207                 ChannelMonitor {
 208                         funding_txo: self.funding_txo.clone(),
 209                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 210
 211                         key_storage: self.key_storage.clone(),
 212                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 213                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 214                         their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
 215                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 216
 217                         our_to_self_delay: self.our_to_self_delay,
 218                         their_to_self_delay: self.their_to_self_delay,
 219
 220                         old_secrets: self.old_secrets.clone(),
 221                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 222                         remote_commitment_txn_on_chain: Mutex::new((*self.remote_commitment_txn_on_chain.lock().unwrap()).clone()),
 223                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 224
 225                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 226                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 227
 228                         payment_preimages: self.payment_preimages.clone(),
 229
 230                         destination_script: self.destination_script.clone(),
 231                         secp_ctx: self.secp_ctx.clone(),
 232                 }
 233         }
 234 }
 235
 236 #[cfg(any(test, feature = "fuzztarget"))]
 237 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 238 /// underlying object
 239 impl PartialEq for ChannelMonitor {
 240         fn eq(&self, other: &Self) -> bool {
 241                 if self.funding_txo != other.funding_txo ||
 242                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 243                         self.key_storage != other.key_storage ||
 244                         self.delayed_payment_base_key != other.delayed_payment_base_key ||
 245                         self.their_htlc_base_key != other.their_htlc_base_key ||
 246                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 247                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 248                         self.our_to_self_delay != other.our_to_self_delay ||
 249                         self.their_to_self_delay != other.their_to_self_delay ||
 250                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 251                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 252                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 253                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 254                         self.payment_preimages != other.payment_preimages ||
 255                         self.destination_script != other.destination_script
 256                 {
 257                         false
 258                 } else {
 259                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 260                                 if secret != o_secret || idx != o_idx {
 261                                         return false
 262                                 }
 263                         }
 264                         let us = self.remote_commitment_txn_on_chain.lock().unwrap();
 265                         let them = other.remote_commitment_txn_on_chain.lock().unwrap();
 266                         *us == *them
 267                 }
 268         }
 269 }
 270
 271 impl ChannelMonitor {
 272         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 {
 273                 ChannelMonitor {
 274                         funding_txo: None,
 275                         commitment_transaction_number_obscure_factor: 0,
 276
 277                         key_storage: KeyStorage::PrivMode {
 278                                 revocation_base_key: revocation_base_key.clone(),
 279                                 htlc_base_key: htlc_base_key.clone(),
 280                         },
 281                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 282                         their_htlc_base_key: None,
 283                         their_delayed_payment_base_key: None,
 284                         their_cur_revocation_points: None,
 285
 286                         our_to_self_delay: our_to_self_delay,
 287                         their_to_self_delay: None,
 288
 289                         old_secrets: [([0; 32], 1 << 48); 49],
 290                         remote_claimable_outpoints: HashMap::new(),
 291                         remote_commitment_txn_on_chain: Mutex::new(HashMap::new()),
 292                         remote_hash_commitment_number: HashMap::new(),
 293
 294                         prev_local_signed_commitment_tx: None,
 295                         current_local_signed_commitment_tx: None,
 296
 297                         payment_preimages: HashMap::new(),
 298
 299                         destination_script: destination_script,
 300                         secp_ctx: Secp256k1::new(),
 301                 }
 302         }
 303
 304         #[inline]
 305         fn place_secret(idx: u64) -> u8 {
 306                 for i in 0..48 {
 307                         if idx & (1 << i) == (1 << i) {
 308                                 return i
 309                         }
 310                 }
 311                 48
 312         }
 313
 314         #[inline]
 315         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 316                 let mut res: [u8; 32] = secret;
 317                 for i in 0..bits {
 318                         let bitpos = bits - 1 - i;
 319                         if idx & (1 << bitpos) == (1 << bitpos) {
 320                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 321                                 let mut sha = Sha256::new();
 322                                 sha.input(&res);
 323                                 sha.result(&mut res);
 324                         }
 325                 }
 326                 res
 327         }
 328
 329         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 330         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 331         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 332         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 333         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 334         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 335                 let pos = ChannelMonitor::place_secret(idx);
 336                 for i in 0..pos {
 337                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 338                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 339                                 return Err(HandleError{err: "Previous secret did not match new one", action: None})
 340                         }
 341                 }
 342                 self.old_secrets[pos as usize] = (secret, idx);
 343
 344                 if let Some(new_revocation_point) = their_next_revocation_point {
 345                         match self.their_cur_revocation_points {
 346                                 Some(old_points) => {
 347                                         if old_points.0 == new_revocation_point.0 + 1 {
 348                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 349                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 350                                                 if let Some(old_second_point) = old_points.2 {
 351                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 352                                                 } else {
 353                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 354                                                 }
 355                                         } else {
 356                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 357                                         }
 358                                 },
 359                                 None => {
 360                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 361                                 }
 362                         }
 363                 }
 364
 365                 if !self.payment_preimages.is_empty() {
 366                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 367                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 368                         let min_idx = self.get_min_seen_secret();
 369                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 370
 371                         self.payment_preimages.retain(|&k, _| {
 372                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 373                                         if k == htlc.payment_hash {
 374                                                 return true
 375                                         }
 376                                 }
 377                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 378                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 379                                                 if k == htlc.payment_hash {
 380                                                         return true
 381                                                 }
 382                                         }
 383                                 }
 384                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 385                                         if *cn < min_idx {
 386                                                 return true
 387                                         }
 388                                         true
 389                                 } else { false };
 390                                 if contains {
 391                                         remote_hash_commitment_number.remove(&k);
 392                                 }
 393                                 false
 394                         });
 395                 }
 396
 397                 Ok(())
 398         }
 399
 400         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 401         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 402         /// possibly future revocation/preimage information) to claim outputs where possible.
 403         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 404         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 405                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 406                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 407                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 408                 // timeouts)
 409                 for htlc in &htlc_outputs {
 410                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 411                 }
 412                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 413         }
 414
 415         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 416         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 417         /// is important that any clones of this channel monitor (including remote clones) by kept
 418         /// up-to-date as our local commitment transaction is updated.
 419         /// Panics if set_their_to_self_delay has never been called.
 420         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)>) {
 421                 assert!(self.their_to_self_delay.is_some());
 422                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 423                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 424                         txid: signed_commitment_tx.txid(),
 425                         tx: signed_commitment_tx,
 426                         revocation_key: local_keys.revocation_key,
 427                         a_htlc_key: local_keys.a_htlc_key,
 428                         b_htlc_key: local_keys.b_htlc_key,
 429                         delayed_payment_key: local_keys.a_delayed_payment_key,
 430                         feerate_per_kw,
 431                         htlc_outputs,
 432                 });
 433         }
 434
 435         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 436         /// commitment_tx_infos which contain the payment hash have been revoked.
 437         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 438                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 439         }
 440
 441         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 442                 if self.funding_txo.is_some() {
 443                         // We should be able to compare the entire funding_txo, but in fuzztarget its trivially
 444                         // easy to collide the funding_txo hash and have a different scriptPubKey.
 445                         if other.funding_txo.is_some() && other.funding_txo.as_ref().unwrap().0 != self.funding_txo.as_ref().unwrap().0 {
 446                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", action: None});
 447                         }
 448                 } else {
 449                         self.funding_txo = other.funding_txo.take();
 450                 }
 451                 let other_min_secret = other.get_min_seen_secret();
 452                 let our_min_secret = self.get_min_seen_secret();
 453                 if our_min_secret > other_min_secret {
 454                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 455                 }
 456                 if our_min_secret >= other_min_secret {
 457                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 458                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 459                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 460                         }
 461                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 462                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 463                         }
 464                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 465                                 self.current_local_signed_commitment_tx = Some(local_tx);
 466                         }
 467                         self.payment_preimages = other.payment_preimages;
 468                 }
 469                 Ok(())
 470         }
 471
 472         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 473         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 474                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 475                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 476         }
 477
 478         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 479         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 480         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 481         /// provides slightly better privacy.
 482         /// It's the responsibility of the caller to register outpoint and script with passing the former
 483         /// value as key to add_update_monitor.
 484         pub(super) fn set_funding_info(&mut self, funding_info: (OutPoint, Script)) {
 485                 self.funding_txo = Some(funding_info);
 486         }
 487
 488         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
 489         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
 490                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 491                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
 492         }
 493
 494         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 495                 self.their_to_self_delay = Some(their_to_self_delay);
 496         }
 497
 498         pub(super) fn unset_funding_info(&mut self) {
 499                 self.funding_txo = None;
 500         }
 501
 502         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 503                 match self.funding_txo {
 504                         Some((outpoint, _)) => Some(outpoint),
 505                         None => None
 506                 }
 507         }
 508
 509         /// Serializes into a vec, with various modes for the exposed pub fns
 510         fn serialize(&self, for_local_storage: bool) -> Vec<u8> {
 511                 let mut res = Vec::new();
 512                 res.push(SERIALIZATION_VERSION);
 513                 res.push(MIN_SERIALIZATION_VERSION);
 514
 515                 match &self.funding_txo {
 516                         &Some((ref outpoint, ref script)) => {
 517                                 res.extend_from_slice(&outpoint.txid[..]);
 518                                 res.extend_from_slice(&byte_utils::be16_to_array(outpoint.index));
 519                                 res.extend_from_slice(&byte_utils::be64_to_array(script.len() as u64));
 520                                 res.extend_from_slice(&script[..]);
 521                         },
 522                         &None => {
 523                                 // We haven't even been initialized...not sure why anyone is serializing us, but
 524                                 // not much to give them.
 525                                 return res;
 526                         },
 527                 }
 528
 529                 // Set in initial Channel-object creation, so should always be set by now:
 530                 res.extend_from_slice(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor));
 531
 532                 match self.key_storage {
 533                         KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 534                                 res.push(0);
 535                                 res.extend_from_slice(&revocation_base_key[..]);
 536                                 res.extend_from_slice(&htlc_base_key[..]);
 537                         },
 538                         KeyStorage::SigsMode { .. } => unimplemented!(),
 539                 }
 540
 541                 res.extend_from_slice(&self.delayed_payment_base_key.serialize());
 542                 res.extend_from_slice(&self.their_htlc_base_key.as_ref().unwrap().serialize());
 543                 res.extend_from_slice(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize());
 544
 545                 match self.their_cur_revocation_points {
 546                         Some((idx, pubkey, second_option)) => {
 547                                 res.extend_from_slice(&byte_utils::be48_to_array(idx));
 548                                 res.extend_from_slice(&pubkey.serialize());
 549                                 match second_option {
 550                                         Some(second_pubkey) => {
 551                                                 res.extend_from_slice(&second_pubkey.serialize());
 552                                         },
 553                                         None => {
 554                                                 res.extend_from_slice(&[0; 33]);
 555                                         },
 556                                 }
 557                         },
 558                         None => {
 559                                 res.extend_from_slice(&byte_utils::be48_to_array(0));
 560                         },
 561                 }
 562
 563                 res.extend_from_slice(&byte_utils::be16_to_array(self.our_to_self_delay));
 564                 res.extend_from_slice(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()));
 565
 566                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 567                         res.extend_from_slice(secret);
 568                         res.extend_from_slice(&byte_utils::be64_to_array(*idx));
 569                 }
 570
 571                 macro_rules! serialize_htlc_in_commitment {
 572                         ($htlc_output: expr) => {
 573                                 res.push($htlc_output.offered as u8);
 574                                 res.extend_from_slice(&byte_utils::be64_to_array($htlc_output.amount_msat));
 575                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.cltv_expiry));
 576                                 res.extend_from_slice(&$htlc_output.payment_hash);
 577                                 res.extend_from_slice(&byte_utils::be32_to_array($htlc_output.transaction_output_index));
 578                         }
 579                 }
 580
 581                 res.extend_from_slice(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64));
 582                 for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
 583                         res.extend_from_slice(&txid[..]);
 584                         res.extend_from_slice(&byte_utils::be64_to_array(htlc_outputs.len() as u64));
 585                         for htlc_output in htlc_outputs.iter() {
 586                                 serialize_htlc_in_commitment!(htlc_output);
 587                         }
 588                 }
 589
 590                 {
 591                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
 592                         res.extend_from_slice(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64));
 593                         for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
 594                                 res.extend_from_slice(&txid[..]);
 595                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 596                         }
 597                 }
 598
 599                 if for_local_storage {
 600                         res.extend_from_slice(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64));
 601                         for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 602                                 res.extend_from_slice(payment_hash);
 603                                 res.extend_from_slice(&byte_utils::be48_to_array(*commitment_number));
 604                         }
 605                 } else {
 606                         res.extend_from_slice(&byte_utils::be64_to_array(0));
 607                 }
 608
 609                 macro_rules! serialize_local_tx {
 610                         ($local_tx: expr) => {
 611                                 let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
 612                                 res.extend_from_slice(&byte_utils::be64_to_array(tx_ser.len() as u64));
 613                                 res.extend_from_slice(&tx_ser);
 614
 615                                 res.extend_from_slice(&$local_tx.revocation_key.serialize());
 616                                 res.extend_from_slice(&$local_tx.a_htlc_key.serialize());
 617                                 res.extend_from_slice(&$local_tx.b_htlc_key.serialize());
 618                                 res.extend_from_slice(&$local_tx.delayed_payment_key.serialize());
 619
 620                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.feerate_per_kw));
 621                                 res.extend_from_slice(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64));
 622                                 for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
 623                                         serialize_htlc_in_commitment!(htlc_output);
 624                                         res.extend_from_slice(&their_sig.serialize_compact(&self.secp_ctx));
 625                                         res.extend_from_slice(&our_sig.serialize_compact(&self.secp_ctx));
 626                                 }
 627                         }
 628                 }
 629
 630                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 631                         res.push(1);
 632                         serialize_local_tx!(prev_local_tx);
 633                 } else {
 634                         res.push(0);
 635                 }
 636
 637                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 638                         res.push(1);
 639                         serialize_local_tx!(cur_local_tx);
 640                 } else {
 641                         res.push(0);
 642                 }
 643
 644                 res.extend_from_slice(&byte_utils::be64_to_array(self.payment_preimages.len() as u64));
 645                 for payment_preimage in self.payment_preimages.values() {
 646                         res.extend_from_slice(payment_preimage);
 647                 }
 648
 649                 res.extend_from_slice(&byte_utils::be64_to_array(self.destination_script.len() as u64));
 650                 res.extend_from_slice(&self.destination_script[..]);
 651
 652                 res
 653         }
 654
 655         /// Encodes this monitor into a byte array, suitable for writing to disk.
 656         pub fn serialize_for_disk(&self) -> Vec<u8> {
 657                 self.serialize(true)
 658         }
 659
 660         /// Encodes this monitor into a byte array, suitable for sending to a remote watchtower
 661         pub fn serialize_for_watchtower(&self) -> Vec<u8> {
 662                 self.serialize(false)
 663         }
 664
 665         /// Attempts to decode a serialized monitor
 666         pub fn deserialize(data: &[u8]) -> Option<Self> {
 667                 let mut read_pos = 0;
 668                 macro_rules! read_bytes {
 669                         ($byte_count: expr) => {
 670                                 {
 671                                         if ($byte_count as usize) > data.len() - read_pos {
 672                                                 return None;
 673                                         }
 674                                         read_pos += $byte_count as usize;
 675                                         &data[read_pos - $byte_count as usize..read_pos]
 676                                 }
 677                         }
 678                 }
 679
 680                 let secp_ctx = Secp256k1::new();
 681                 macro_rules! unwrap_obj {
 682                         ($key: expr) => {
 683                                 match $key {
 684                                         Ok(res) => res,
 685                                         Err(_) => return None,
 686                                 }
 687                         }
 688                 }
 689
 690                 let _ver = read_bytes!(1)[0];
 691                 let min_ver = read_bytes!(1)[0];
 692                 if min_ver > SERIALIZATION_VERSION {
 693                         return None;
 694                 }
 695
 696                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
 697                 // barely-init'd ChannelMonitors that we can't do anything with.
 698                 let outpoint = OutPoint {
 699                         txid: Sha256dHash::from(read_bytes!(32)),
 700                         index: byte_utils::slice_to_be16(read_bytes!(2)),
 701                 };
 702                 let script_len = byte_utils::slice_to_be64(read_bytes!(8));
 703                 let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
 704                 let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
 705
 706                 let key_storage = match read_bytes!(1)[0] {
 707                         0 => {
 708                                 KeyStorage::PrivMode {
 709                                         revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 710                                         htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
 711                                 }
 712                         },
 713                         _ => return None,
 714                 };
 715
 716                 let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 717                 let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 718                 let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
 719
 720                 let their_cur_revocation_points = {
 721                         let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
 722                         if first_idx == 0 {
 723                                 None
 724                         } else {
 725                                 let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 726                                 let second_point_slice = read_bytes!(33);
 727                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
 728                                         Some((first_idx, first_point, None))
 729                                 } else {
 730                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
 731                                 }
 732                         }
 733                 };
 734
 735                 let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
 736                 let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
 737
 738                 let mut old_secrets = [([0; 32], 1 << 48); 49];
 739                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
 740                         secret.copy_from_slice(read_bytes!(32));
 741                         *idx = byte_utils::slice_to_be64(read_bytes!(8));
 742                 }
 743
 744                 macro_rules! read_htlc_in_commitment {
 745                         () => {
 746                                 {
 747                                         let offered = match read_bytes!(1)[0] {
 748                                                 0 => false, 1 => true,
 749                                                 _ => return None,
 750                                         };
 751                                         let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
 752                                         let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
 753                                         let mut payment_hash = [0; 32];
 754                                         payment_hash[..].copy_from_slice(read_bytes!(32));
 755                                         let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
 756
 757                                         HTLCOutputInCommitment {
 758                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
 759                                         }
 760                                 }
 761                         }
 762                 }
 763
 764                 let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
 765                 if remote_claimable_outpoints_len > data.len() as u64 / 64 { return None; }
 766                 let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
 767                 for _ in 0..remote_claimable_outpoints_len {
 768                         let txid = Sha256dHash::from(read_bytes!(32));
 769                         let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
 770                         if outputs_count > data.len() as u64 / 32 { return None; }
 771                         let mut outputs = Vec::with_capacity(outputs_count as usize);
 772                         for _ in 0..outputs_count {
 773                                 outputs.push(read_htlc_in_commitment!());
 774                         }
 775                         if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
 776                                 return None;
 777                         }
 778                 }
 779
 780                 let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
 781                 if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return None; }
 782                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
 783                 for _ in 0..remote_commitment_txn_on_chain_len {
 784                         let txid = Sha256dHash::from(read_bytes!(32));
 785                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 786                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
 787                                 return None;
 788                         }
 789                 }
 790
 791                 let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
 792                 if remote_hash_commitment_number_len > data.len() as u64 / 32 { return None; }
 793                 let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
 794                 for _ in 0..remote_hash_commitment_number_len {
 795                         let mut txid = [0; 32];
 796                         txid[..].copy_from_slice(read_bytes!(32));
 797                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
 798                         if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
 799                                 return None;
 800                         }
 801                 }
 802
 803                 macro_rules! read_local_tx {
 804                         () => {
 805                                 {
 806                                         let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
 807                                         let tx_ser = read_bytes!(tx_len);
 808                                         let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
 809                                         if serialize::serialize(&tx).unwrap() != tx_ser {
 810                                                 // We check that the tx re-serializes to the same form to ensure there is
 811                                                 // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
 812                                                 // all that well.
 813                                                 return None;
 814                                         }
 815
 816                                         let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 817                                         let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 818                                         let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 819                                         let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
 820                                         let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
 821
 822                                         let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
 823                                         if htlc_outputs_len > data.len() as u64 / 128 { return None; }
 824                                         let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
 825                                         for _ in 0..htlc_outputs_len {
 826                                                 htlc_outputs.push((read_htlc_in_commitment!(),
 827                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
 828                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
 829                                         }
 830
 831                                         LocalSignedTx {
 832                                                 txid: tx.txid(),
 833                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
 834                                         }
 835                                 }
 836                         }
 837                 }
 838
 839                 let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
 840                         0 => None,
 841                         1 => {
 842                                 Some(read_local_tx!())
 843                         },
 844                         _ => return None,
 845                 };
 846
 847                 let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
 848                         0 => None,
 849                         1 => {
 850                                 Some(read_local_tx!())
 851                         },
 852                         _ => return None,
 853                 };
 854
 855                 let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
 856                 if payment_preimages_len > data.len() as u64 / 32 { return None; }
 857                 let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
 858                 let mut sha = Sha256::new();
 859                 for _ in 0..payment_preimages_len {
 860                         let mut preimage = [0; 32];
 861                         preimage[..].copy_from_slice(read_bytes!(32));
 862                         sha.reset();
 863                         sha.input(&preimage);
 864                         let mut hash = [0; 32];
 865                         sha.result(&mut hash);
 866                         if let Some(_) = payment_preimages.insert(hash, preimage) {
 867                                 return None;
 868                         }
 869                 }
 870
 871                 let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
 872                 let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
 873
 874                 Some(ChannelMonitor {
 875                         funding_txo,
 876                         commitment_transaction_number_obscure_factor,
 877
 878                         key_storage,
 879                         delayed_payment_base_key,
 880                         their_htlc_base_key,
 881                         their_delayed_payment_base_key,
 882                         their_cur_revocation_points,
 883
 884                         our_to_self_delay,
 885                         their_to_self_delay,
 886
 887                         old_secrets,
 888                         remote_claimable_outpoints,
 889                         remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
 890                         remote_hash_commitment_number,
 891
 892                         prev_local_signed_commitment_tx,
 893                         current_local_signed_commitment_tx,
 894
 895                         payment_preimages,
 896
 897                         destination_script,
 898                         secp_ctx,
 899                 })
 900         }
 901
 902         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 903         //we want to leave out (eg funding_txo, etc).
 904
 905         /// Can only fail if idx is < get_min_seen_secret
 906         pub fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 907                 for i in 0..self.old_secrets.len() {
 908                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 909                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 910                         }
 911                 }
 912                 assert!(idx < self.get_min_seen_secret());
 913                 Err(HandleError{err: "idx too low", action: None})
 914         }
 915
 916         pub fn get_min_seen_secret(&self) -> u64 {
 917                 //TODO This can be optimized?
 918                 let mut min = 1 << 48;
 919                 for &(_, idx) in self.old_secrets.iter() {
 920                         if idx < min {
 921                                 min = idx;
 922                         }
 923                 }
 924                 min
 925         }
 926
 927         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 928         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 929         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 930         /// HTLC-Success/HTLC-Timeout transactions.
 931         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
 932                 // Most secp and related errors trying to create keys means we have no hope of constructing
 933                 // a spend transaction...so we return no transactions to broadcast
 934                 let mut txn_to_broadcast = Vec::new();
 935                 let mut watch_outputs = Vec::new();
 936
 937                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 938                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 939
 940                 macro_rules! ignore_error {
 941                         ( $thing : expr ) => {
 942                                 match $thing {
 943                                         Ok(a) => a,
 944                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs))
 945                                 }
 946                         };
 947                 }
 948
 949                 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);
 950                 if commitment_number >= self.get_min_seen_secret() {
 951                         let secret = self.get_secret(commitment_number).unwrap();
 952                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 953                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 954                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 955                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 956                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 957                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 958                                 },
 959                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 960                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 961                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 962                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 963                                 },
 964                         };
 965                         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));
 966                         let a_htlc_key = match self.their_htlc_base_key {
 967                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 968                                 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)),
 969                         };
 970
 971                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 972                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 973
 974                         let mut total_value = 0;
 975                         let mut values = Vec::new();
 976                         let mut inputs = Vec::new();
 977                         let mut htlc_idxs = Vec::new();
 978
 979                         for (idx, outp) in tx.output.iter().enumerate() {
 980                                 if outp.script_pubkey == revokeable_p2wsh {
 981                                         inputs.push(TxIn {
 982                                                 previous_output: BitcoinOutPoint {
 983                                                         txid: commitment_txid,
 984                                                         vout: idx as u32,
 985                                                 },
 986                                                 script_sig: Script::new(),
 987                                                 sequence: 0xfffffffd,
 988                                                 witness: Vec::new(),
 989                                         });
 990                                         htlc_idxs.push(None);
 991                                         values.push(outp.value);
 992                                         total_value += outp.value;
 993                                         break; // There can only be one of these
 994                                 }
 995                         }
 996
 997                         macro_rules! sign_input {
 998                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 999                                         {
1000                                                 let (sig, redeemscript) = match self.key_storage {
1001                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1002                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
1003                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
1004                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
1005                                                                 };
1006                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
1007                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1008                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
1009                                                         },
1010                                                         KeyStorage::SigsMode { .. } => {
1011                                                                 unimplemented!();
1012                                                         }
1013                                                 };
1014                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1015                                                 $input.witness[0].push(SigHashType::All as u8);
1016                                                 if $htlc_idx.is_none() {
1017                                                         $input.witness.push(vec!(1));
1018                                                 } else {
1019                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
1020                                                 }
1021                                                 $input.witness.push(redeemscript.into_bytes());
1022                                         }
1023                                 }
1024                         }
1025
1026                         if let Some(per_commitment_data) = per_commitment_option {
1027                                 inputs.reserve_exact(per_commitment_data.len());
1028
1029                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
1030                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1031                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
1032                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1033                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1034                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
1035                                         }
1036                                         let input = TxIn {
1037                                                 previous_output: BitcoinOutPoint {
1038                                                         txid: commitment_txid,
1039                                                         vout: htlc.transaction_output_index,
1040                                                 },
1041                                                 script_sig: Script::new(),
1042                                                 sequence: 0xfffffffd,
1043                                                 witness: Vec::new(),
1044                                         };
1045                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1046                                                 inputs.push(input);
1047                                                 htlc_idxs.push(Some(idx));
1048                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
1049                                                 total_value += htlc.amount_msat / 1000;
1050                                         } else {
1051                                                 let mut single_htlc_tx = Transaction {
1052                                                         version: 2,
1053                                                         lock_time: 0,
1054                                                         input: vec![input],
1055                                                         output: vec!(TxOut {
1056                                                                 script_pubkey: self.destination_script.clone(),
1057                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1058                                                         }),
1059                                                 };
1060                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1061                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
1062                                                 txn_to_broadcast.push(single_htlc_tx); // TODO: This is not yet tested in ChannelManager!
1063                                         }
1064                                 }
1065                         }
1066
1067                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours
1068                                 // We're definitely a remote commitment transaction!
1069                                 watch_outputs.append(&mut tx.output.clone());
1070                                 self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1071                         }
1072                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
1073
1074                         let outputs = vec!(TxOut {
1075                                 script_pubkey: self.destination_script.clone(),
1076                                 value: total_value, //TODO: - fee
1077                         });
1078                         let mut spend_tx = Transaction {
1079                                 version: 2,
1080                                 lock_time: 0,
1081                                 input: inputs,
1082                                 output: outputs,
1083                         };
1084
1085                         let mut values_drain = values.drain(..);
1086                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1087
1088                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
1089                                 let value = values_drain.next().unwrap();
1090                                 sign_input!(sighash_parts, input, htlc_idx, value);
1091                         }
1092
1093                         txn_to_broadcast.push(spend_tx);
1094                 } else if let Some(per_commitment_data) = per_commitment_option {
1095                         // While this isn't useful yet, there is a potential race where if a counterparty
1096                         // revokes a state at the same time as the commitment transaction for that state is
1097                         // confirmed, and the watchtower receives the block before the user, the user could
1098                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
1099                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1100                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
1101                         // insert it here.
1102                         watch_outputs.append(&mut tx.output.clone());
1103                         self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
1104
1105                         if let Some(revocation_points) = self.their_cur_revocation_points {
1106                                 let revocation_point_option =
1107                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1108                                         else if let Some(point) = revocation_points.2.as_ref() {
1109                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1110                                         } else { None };
1111                                 if let Some(revocation_point) = revocation_point_option {
1112                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
1113                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
1114                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1115                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
1116                                                 },
1117                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
1118                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
1119                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1120                                                 },
1121                                         };
1122                                         let a_htlc_key = match self.their_htlc_base_key {
1123                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
1124                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1125                                         };
1126
1127                                         let mut total_value = 0;
1128                                         let mut values = Vec::new();
1129                                         let mut inputs = Vec::new();
1130
1131                                         macro_rules! sign_input {
1132                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
1133                                                         {
1134                                                                 let (sig, redeemscript) = match self.key_storage {
1135                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
1136                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
1137                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1138                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
1139                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
1140                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
1141                                                                         },
1142                                                                         KeyStorage::SigsMode { .. } => {
1143                                                                                 unimplemented!();
1144                                                                         }
1145                                                                 };
1146                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1147                                                                 $input.witness[0].push(SigHashType::All as u8);
1148                                                                 $input.witness.push($preimage);
1149                                                                 $input.witness.push(redeemscript.into_bytes());
1150                                                         }
1151                                                 }
1152                                         }
1153
1154                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
1155                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1156                                                         let input = TxIn {
1157                                                                 previous_output: BitcoinOutPoint {
1158                                                                         txid: commitment_txid,
1159                                                                         vout: htlc.transaction_output_index,
1160                                                                 },
1161                                                                 script_sig: Script::new(),
1162                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
1163                                                                 witness: Vec::new(),
1164                                                         };
1165                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1166                                                                 inputs.push(input);
1167                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
1168                                                                 total_value += htlc.amount_msat / 1000;
1169                                                         } else {
1170                                                                 let mut single_htlc_tx = Transaction {
1171                                                                         version: 2,
1172                                                                         lock_time: 0,
1173                                                                         input: vec![input],
1174                                                                         output: vec!(TxOut {
1175                                                                                 script_pubkey: self.destination_script.clone(),
1176                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
1177                                                                         }),
1178                                                                 };
1179                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1180                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
1181                                                                 txn_to_broadcast.push(single_htlc_tx);
1182                                                         }
1183                                                 }
1184                                         }
1185
1186                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
1187
1188                                         let outputs = vec!(TxOut {
1189                                                 script_pubkey: self.destination_script.clone(),
1190                                                 value: total_value, //TODO: - fee
1191                                         });
1192                                         let mut spend_tx = Transaction {
1193                                                 version: 2,
1194                                                 lock_time: 0,
1195                                                 input: inputs,
1196                                                 output: outputs,
1197                                         };
1198
1199                                         let mut values_drain = values.drain(..);
1200                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1201
1202                                         for input in spend_tx.input.iter_mut() {
1203                                                 let value = values_drain.next().unwrap();
1204                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
1205                                         }
1206
1207                                         txn_to_broadcast.push(spend_tx);
1208                                 }
1209                         }
1210                 }
1211
1212                 (txn_to_broadcast, (commitment_txid, watch_outputs))
1213         }
1214
1215         /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
1216         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
1217                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1218
1219                 macro_rules! ignore_error {
1220                         ( $thing : expr ) => {
1221                                 match $thing {
1222                                         Ok(a) => a,
1223                                         Err(_) => return None
1224                                 }
1225                         };
1226                 }
1227
1228                 let secret = ignore_error!(self.get_secret(commitment_number));
1229                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
1230                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1231                 let revocation_pubkey = match self.key_storage {
1232                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1233                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1234                         },
1235                         KeyStorage::SigsMode { ref revocation_base_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 None,
1241                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &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                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1276
1277                         let sig = match self.key_storage {
1278                                 KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1279                                         let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]));
1280                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1281                                         self.secp_ctx.sign(&sighash, &revocation_key)
1282                                 }
1283                                 KeyStorage::SigsMode { .. } => {
1284                                         unimplemented!();
1285                                 }
1286                         };
1287                         spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1288                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1289                         spend_tx.input[0].witness.push(vec!(1));
1290                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1291
1292                         Some(spend_tx)
1293                 } else { None }
1294         }
1295
1296         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
1297                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1298
1299                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
1300                         if htlc.offered {
1301                                 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);
1302
1303                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1304
1305                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1306                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1307                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1308                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1309
1310                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1311                                 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());
1312
1313                                 res.push(htlc_timeout_tx);
1314                         } else {
1315                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1316                                         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);
1317
1318                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1319
1320                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1321                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1322                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1323                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1324
1325                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
1326                                         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());
1327
1328                                         res.push(htlc_success_tx);
1329                                 }
1330                         }
1331                 }
1332
1333                 res
1334         }
1335
1336         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1337         /// revoked using data in local_claimable_outpoints.
1338         /// Should not be used if check_spend_revoked_transaction succeeds.
1339         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
1340                 let commitment_txid = tx.txid();
1341                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1342                         if local_tx.txid == commitment_txid {
1343                                 return self.broadcast_by_local_state(local_tx);
1344                         }
1345                 }
1346                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1347                         if local_tx.txid == commitment_txid {
1348                                 return self.broadcast_by_local_state(local_tx);
1349                         }
1350                 }
1351                 Vec::new()
1352         }
1353
1354         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
1355                 let mut watch_outputs = Vec::new();
1356                 for tx in txn_matched {
1357                         if tx.input.len() == 1 {
1358                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1359                                 // commitment transactions and HTLC transactions will all only ever have one input,
1360                                 // which is an easy way to filter out any potential non-matching txn for lazy
1361                                 // filters.
1362                                 let prevout = &tx.input[0].previous_output;
1363                                 let mut txn: Vec<Transaction> = Vec::new();
1364                                 if self.funding_txo.is_none() || (prevout.txid == self.funding_txo.as_ref().unwrap().0.txid && prevout.vout == self.funding_txo.as_ref().unwrap().0.index as u32) {
1365                                         let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
1366                                         txn = remote_txn;
1367                                         if !new_outputs.1.is_empty() {
1368                                                 watch_outputs.push(new_outputs);
1369                                         }
1370                                         if txn.is_empty() {
1371                                                 txn = self.check_spend_local_transaction(tx, height);
1372                                         }
1373                                 } else {
1374                                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
1375                                         if let Some(commitment_number) = remote_commitment_txn_on_chain.get(&prevout.txid) {
1376                                                 if let Some(tx) = self.check_spend_remote_htlc(tx, *commitment_number) {
1377                                                         txn.push(tx);
1378                                                 }
1379                                         }
1380                                 }
1381                                 for tx in txn.iter() {
1382                                         broadcaster.broadcast_transaction(tx);
1383                                 }
1384                         }
1385                 }
1386                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1387                         let mut needs_broadcast = false;
1388                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1389                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1390                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1391                                                 needs_broadcast = true;
1392                                         }
1393                                 }
1394                         }
1395
1396                         if needs_broadcast {
1397                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1398                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
1399                                         broadcaster.broadcast_transaction(&tx);
1400                                 }
1401                         }
1402                 }
1403                 watch_outputs
1404         }
1405
1406         pub fn would_broadcast_at_height(&self, height: u32) -> bool {
1407                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1408                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1409                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1410                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1411                                                 return true;
1412                                         }
1413                                 }
1414                         }
1415                 }
1416                 false
1417         }
1418 }
1419
1420 #[cfg(test)]
1421 mod tests {
1422         use bitcoin::blockdata::script::Script;
1423         use bitcoin::blockdata::transaction::Transaction;
1424         use crypto::digest::Digest;
1425         use hex;
1426         use ln::channelmonitor::ChannelMonitor;
1427         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
1428         use util::sha2::Sha256;
1429         use secp256k1::key::{SecretKey,PublicKey};
1430         use secp256k1::{Secp256k1, Signature};
1431         use rand::{thread_rng,Rng};
1432
1433         #[test]
1434         fn test_per_commitment_storage() {
1435                 // Test vectors from BOLT 3:
1436                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1437                 let mut monitor: ChannelMonitor;
1438                 let secp_ctx = Secp256k1::new();
1439
1440                 macro_rules! test_secrets {
1441                         () => {
1442                                 let mut idx = 281474976710655;
1443                                 for secret in secrets.iter() {
1444                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1445                                         idx -= 1;
1446                                 }
1447                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1448                                 assert!(monitor.get_secret(idx).is_err());
1449                         };
1450                 }
1451
1452                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1453
1454                 {
1455                         // insert_secret correct sequence
1456                         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());
1457                         secrets.clear();
1458
1459                         secrets.push([0; 32]);
1460                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1461                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1466                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1471                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1476                         monitor.provide_secret(281474976710652, 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("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1481                         monitor.provide_secret(281474976710651, 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("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1486                         monitor.provide_secret(281474976710650, 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("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1491                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1492                         test_secrets!();
1493
1494                         secrets.push([0; 32]);
1495                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1496                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
1497                         test_secrets!();
1498                 }
1499
1500                 {
1501                         // insert_secret #1 incorrect
1502                         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());
1503                         secrets.clear();
1504
1505                         secrets.push([0; 32]);
1506                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1507                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1508                         test_secrets!();
1509
1510                         secrets.push([0; 32]);
1511                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1512                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
1513                                         "Previous secret did not match new one");
1514                 }
1515
1516                 {
1517                         // insert_secret #2 incorrect (#1 derived from incorrect)
1518                         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());
1519                         secrets.clear();
1520
1521                         secrets.push([0; 32]);
1522                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1523                         monitor.provide_secret(281474976710655, 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("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1528                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1533                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1534                         test_secrets!();
1535
1536                         secrets.push([0; 32]);
1537                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1538                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1539                                         "Previous secret did not match new one");
1540                 }
1541
1542                 {
1543                         // insert_secret #3 incorrect
1544                         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());
1545                         secrets.clear();
1546
1547                         secrets.push([0; 32]);
1548                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1549                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1554                         monitor.provide_secret(281474976710654, 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("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1559                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1560                         test_secrets!();
1561
1562                         secrets.push([0; 32]);
1563                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1564                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1565                                         "Previous secret did not match new one");
1566                 }
1567
1568                 {
1569                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1570                         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());
1571                         secrets.clear();
1572
1573                         secrets.push([0; 32]);
1574                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1575                         monitor.provide_secret(281474976710655, 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("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1580                         monitor.provide_secret(281474976710654, 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("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1585                         monitor.provide_secret(281474976710653, 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("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1590                         monitor.provide_secret(281474976710652, 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("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1595                         monitor.provide_secret(281474976710651, 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("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1600                         monitor.provide_secret(281474976710650, 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("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1605                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1606                         test_secrets!();
1607
1608                         secrets.push([0; 32]);
1609                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1610                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1611                                         "Previous secret did not match new one");
1612                 }
1613
1614                 {
1615                         // insert_secret #5 incorrect
1616                         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());
1617                         secrets.clear();
1618
1619                         secrets.push([0; 32]);
1620                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1621                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1626                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1631                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1636                         monitor.provide_secret(281474976710652, 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("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1641                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1642                         test_secrets!();
1643
1644                         secrets.push([0; 32]);
1645                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1646                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1647                                         "Previous secret did not match new one");
1648                 }
1649
1650                 {
1651                         // insert_secret #6 incorrect (5 derived from incorrect)
1652                         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());
1653                         secrets.clear();
1654
1655                         secrets.push([0; 32]);
1656                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1657                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1662                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1667                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1672                         monitor.provide_secret(281474976710652, 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("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1677                         monitor.provide_secret(281474976710651, 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("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1682                         monitor.provide_secret(281474976710650, 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("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1687                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1688                         test_secrets!();
1689
1690                         secrets.push([0; 32]);
1691                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1692                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1693                                         "Previous secret did not match new one");
1694                 }
1695
1696                 {
1697                         // insert_secret #7 incorrect
1698                         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());
1699                         secrets.clear();
1700
1701                         secrets.push([0; 32]);
1702                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1703                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1708                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1713                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1718                         monitor.provide_secret(281474976710652, 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("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1723                         monitor.provide_secret(281474976710651, 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("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1728                         monitor.provide_secret(281474976710650, 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("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1733                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1734                         test_secrets!();
1735
1736                         secrets.push([0; 32]);
1737                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1738                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1739                                         "Previous secret did not match new one");
1740                 }
1741
1742                 {
1743                         // insert_secret #8 incorrect
1744                         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());
1745                         secrets.clear();
1746
1747                         secrets.push([0; 32]);
1748                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1749                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1754                         monitor.provide_secret(281474976710654, 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("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1759                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1764                         monitor.provide_secret(281474976710652, 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("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1769                         monitor.provide_secret(281474976710651, 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("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1774                         monitor.provide_secret(281474976710650, 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("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1779                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1780                         test_secrets!();
1781
1782                         secrets.push([0; 32]);
1783                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1784                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1785                                         "Previous secret did not match new one");
1786                 }
1787         }
1788
1789         #[test]
1790         fn test_prune_preimages() {
1791                 let secp_ctx = Secp256k1::new();
1792                 let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap();
1793
1794                 macro_rules! dummy_keys {
1795                         () => {
1796                                 {
1797                                         let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1798                                         TxCreationKeys {
1799                                                 per_commitment_point: dummy_key.clone(),
1800                                                 revocation_key: dummy_key.clone(),
1801                                                 a_htlc_key: dummy_key.clone(),
1802                                                 b_htlc_key: dummy_key.clone(),
1803                                                 a_delayed_payment_key: dummy_key.clone(),
1804                                                 b_payment_key: dummy_key.clone(),
1805                                         }
1806                                 }
1807                         }
1808                 }
1809                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
1810
1811                 let mut preimages = Vec::new();
1812                 {
1813                         let mut rng  = thread_rng();
1814                         for _ in 0..20 {
1815                                 let mut preimage = [0; 32];
1816                                 rng.fill_bytes(&mut preimage);
1817                                 let mut sha = Sha256::new();
1818                                 sha.input(&preimage);
1819                                 let mut hash = [0; 32];
1820                                 sha.result(&mut hash);
1821                                 preimages.push((preimage, hash));
1822                         }
1823                 }
1824
1825                 macro_rules! preimages_slice_to_htlc_outputs {
1826                         ($preimages_slice: expr) => {
1827                                 {
1828                                         let mut res = Vec::new();
1829                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
1830                                                 res.push(HTLCOutputInCommitment {
1831                                                         offered: true,
1832                                                         amount_msat: 0,
1833                                                         cltv_expiry: 0,
1834                                                         payment_hash: preimage.1.clone(),
1835                                                         transaction_output_index: idx as u32,
1836                                                 });
1837                                         }
1838                                         res
1839                                 }
1840                         }
1841                 }
1842                 macro_rules! preimages_to_local_htlcs {
1843                         ($preimages_slice: expr) => {
1844                                 {
1845                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
1846                                         let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect();
1847                                         res
1848                                 }
1849                         }
1850                 }
1851
1852                 macro_rules! test_preimages_exist {
1853                         ($preimages_slice: expr, $monitor: expr) => {
1854                                 for preimage in $preimages_slice {
1855                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
1856                                 }
1857                         }
1858                 }
1859
1860                 // Prune with one old state and a local commitment tx holding a few overlaps with the
1861                 // old state.
1862                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1863                 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());
1864                 monitor.set_their_to_self_delay(10);
1865
1866                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
1867                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655);
1868                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654);
1869                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653);
1870                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652);
1871                 for &(ref preimage, ref hash) in preimages.iter() {
1872                         monitor.provide_payment_preimage(hash, preimage);
1873                 }
1874
1875                 // Now provide a secret, pruning preimages 10-15
1876                 let mut secret = [0; 32];
1877                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1878                 monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1879                 assert_eq!(monitor.payment_preimages.len(), 15);
1880                 test_preimages_exist!(&preimages[0..10], monitor);
1881                 test_preimages_exist!(&preimages[15..20], monitor);
1882
1883                 // Now provide a further secret, pruning preimages 15-17
1884                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1885                 monitor.provide_secret(281474976710654, secret.clone(), None).unwrap();
1886                 assert_eq!(monitor.payment_preimages.len(), 13);
1887                 test_preimages_exist!(&preimages[0..10], monitor);
1888                 test_preimages_exist!(&preimages[17..20], monitor);
1889
1890                 // Now update local commitment tx info, pruning only element 18 as we still care about the
1891                 // previous commitment tx's preimages too
1892                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
1893                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1894                 monitor.provide_secret(281474976710653, secret.clone(), None).unwrap();
1895                 assert_eq!(monitor.payment_preimages.len(), 12);
1896                 test_preimages_exist!(&preimages[0..10], monitor);
1897                 test_preimages_exist!(&preimages[18..20], monitor);
1898
1899                 // But if we do it again, we'll prune 5-10
1900                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
1901                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1902                 monitor.provide_secret(281474976710652, secret.clone(), None).unwrap();
1903                 assert_eq!(monitor.payment_preimages.len(), 5);
1904                 test_preimages_exist!(&preimages[0..5], monitor);
1905         }
1906
1907         // Further testing is done in the ChannelManager integration tests.
1908 }