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

   1 //! The logic to monitor for on-chain transactions and create the relevant claim responses lives
   2 //! here.
   3 //!
   4 //! ChannelMonitor objects are generated by ChannelManager in response to relevant
   5 //! messages/actions, and MUST be persisted to disk (and, preferably, remotely) before progress can
   6 //! be made in responding to certain messages, see ManyChannelMonitor for more.
   7 //!
   8 //! Note that ChannelMonitors are an important part of the lightning trust model and a copy of the
   9 //! latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date
  10 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
  11 //! security-domain-separated system design, you should consider having multiple paths for
  12 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
  13
  14 use bitcoin::blockdata::block::BlockHeader;
  15 use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction};
  16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  17 use bitcoin::blockdata::script::Script;
  18 use bitcoin::network::serialize;
  19 use bitcoin::util::hash::Sha256dHash;
  20 use bitcoin::util::bip143;
  21
  22 use crypto::digest::Digest;
  23
  24 use secp256k1::{Secp256k1,Message,Signature};
  25 use secp256k1::key::{SecretKey,PublicKey};
  26 use secp256k1;
  27
  28 use ln::msgs::{DecodeError, HandleError};
  29 use ln::chan_utils;
  30 use ln::chan_utils::HTLCOutputInCommitment;
  31 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
  32 use chain::transaction::OutPoint;
  33 use util::ser::{Readable, Writer};
  34 use util::sha2::Sha256;
  35 use util::byte_utils;
  36
  37 use std::collections::HashMap;
  38 use std::sync::{Arc,Mutex};
  39 use std::{hash,cmp};
  40
  41 /// An error enum representing a failure to persist a channel monitor update.
  42 #[derive(Clone)]
  43 pub enum ChannelMonitorUpdateErr {
  44         /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
  45         /// to succeed at some point in the future).
  46         ///
  47         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  48         /// submitting new commitment transactions to the remote party.
  49         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  50         /// the channel to an operational state.
  51         ///
  52         /// Note that continuing to operate when no copy of the updated ChannelMonitor could be
  53         /// persisted is unsafe - if you failed to store the update on your own local disk you should
  54         /// instead return PermanentFailure to force closure of the channel ASAP.
  55         ///
  56         /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
  57         /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
  58         /// to claim it on this channel) and those updates must be applied wherever they can be. At
  59         /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
  60         /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
  61         /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
  62         /// been "frozen".
  63         ///
  64         /// Note that even if updates made after TemporaryFailure succeed you must still call
  65         /// test_restore_channel_monitor to ensure you have the latest monitor and re-enable normal
  66         /// channel operation.
  67         TemporaryFailure,
  68         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  69         /// different watchtower and cannot update with all watchtowers that were previously informed
  70         /// of this channel). This will force-close the channel in question.
  71         PermanentFailure,
  72 }
  73
  74 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
  75 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
  76 /// events to it, while also taking any add_update_monitor events and passing them to some remote
  77 /// server(s).
  78 ///
  79 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
  80 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
  81 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
  82 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
  83 pub trait ManyChannelMonitor: Send + Sync {
  84         /// Adds or updates a monitor for the given `funding_txo`.
  85         ///
  86         /// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
  87         /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
  88         /// any spends of it.
  89         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
  90 }
  91
  92 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
  93 /// watchtower or watch our own channels.
  94 ///
  95 /// Note that you must provide your own key by which to refer to channels.
  96 ///
  97 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
  98 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
  99 /// index by a PublicKey which is required to sign any updates.
 100 ///
 101 /// If you're using this for local monitoring of your own channels, you probably want to use
 102 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
 103 pub struct SimpleManyChannelMonitor<Key> {
 104         #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
 105         pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
 106         #[cfg(not(test))]
 107         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
 108         chain_monitor: Arc<ChainWatchInterface>,
 109         broadcaster: Arc<BroadcasterInterface>
 110 }
 111
 112 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
 113         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
 114                 let monitors = self.monitors.lock().unwrap();
 115                 for monitor in monitors.values() {
 116                         let txn_outputs = monitor.block_connected(txn_matched, height, &*self.broadcaster);
 117                         for (ref txid, ref outputs) in txn_outputs {
 118                                 for (idx, output) in outputs.iter().enumerate() {
 119                                         self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
 120                                 }
 121                         }
 122                 }
 123         }
 124
 125         fn block_disconnected(&self, _: &BlockHeader) { }
 126 }
 127
 128 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
 129         /// Creates a new object which can be used to monitor several channels given the chain
 130         /// interface with which to register to receive notifications.
 131         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
 132                 let res = Arc::new(SimpleManyChannelMonitor {
 133                         monitors: Mutex::new(HashMap::new()),
 134                         chain_monitor,
 135                         broadcaster
 136                 });
 137                 let weak_res = Arc::downgrade(&res);
 138                 res.chain_monitor.register_listener(weak_res);
 139                 res
 140         }
 141
 142         /// Adds or udpates the monitor which monitors the channel referred to by the given key.
 143         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
 144                 let mut monitors = self.monitors.lock().unwrap();
 145                 match monitors.get_mut(&key) {
 146                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
 147                         None => {}
 148                 };
 149                 match &monitor.funding_txo {
 150                         &None => self.chain_monitor.watch_all_txn(),
 151                         &Some((ref outpoint, ref script)) => {
 152                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
 153                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
 154                         },
 155                 }
 156                 monitors.insert(key, monitor);
 157                 Ok(())
 158         }
 159 }
 160
 161 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 162         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 163                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 164                         Ok(_) => Ok(()),
 165                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 166                 }
 167         }
 168 }
 169
 170 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 171 /// instead claiming it in its own individual transaction.
 172 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 173 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 174 /// HTLC-Success transaction.
 175 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
 176 /// transaction confirmed (and we use it in a few more, equivalent, places).
 177 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
 178 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
 179 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
 180 /// copies of ChannelMonitors, including watchtowers).
 181 pub(crate) const HTLC_FAIL_TIMEOUT_BLOCKS: u32 = 3;
 182
 183 #[derive(Clone, PartialEq)]
 184 enum KeyStorage {
 185         PrivMode {
 186                 revocation_base_key: SecretKey,
 187                 htlc_base_key: SecretKey,
 188         },
 189         SigsMode {
 190                 revocation_base_key: PublicKey,
 191                 htlc_base_key: PublicKey,
 192                 sigs: HashMap<Sha256dHash, Signature>,
 193         }
 194 }
 195
 196 #[derive(Clone, PartialEq)]
 197 struct LocalSignedTx {
 198         /// txid of the transaction in tx, just used to make comparison faster
 199         txid: Sha256dHash,
 200         tx: Transaction,
 201         revocation_key: PublicKey,
 202         a_htlc_key: PublicKey,
 203         b_htlc_key: PublicKey,
 204         delayed_payment_key: PublicKey,
 205         feerate_per_kw: u64,
 206         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 207 }
 208
 209 const SERIALIZATION_VERSION: u8 = 1;
 210 const MIN_SERIALIZATION_VERSION: u8 = 1;
 211
 212 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
 213 /// on-chain transactions to ensure no loss of funds occurs.
 214 ///
 215 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
 216 /// information and are actively monitoring the chain.
 217 pub struct ChannelMonitor {
 218         funding_txo: Option<(OutPoint, Script)>,
 219         commitment_transaction_number_obscure_factor: u64,
 220
 221         key_storage: KeyStorage,
 222         delayed_payment_base_key: PublicKey,
 223         their_htlc_base_key: Option<PublicKey>,
 224         their_delayed_payment_base_key: Option<PublicKey>,
 225         // first is the idx of the first of the two revocation points
 226         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 227
 228         our_to_self_delay: u16,
 229         their_to_self_delay: Option<u16>,
 230
 231         old_secrets: [([u8; 32], u64); 49],
 232         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 233         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 234         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 235         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 236         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 237         /// can be used to derive the revocation key and claim the transactions.
 238         remote_commitment_txn_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 239         /// Cache used to make pruning of payment_preimages faster.
 240         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 241         /// remote transactions (ie should remain pretty small).
 242         /// Serialized to disk but should generally not be sent to Watchtowers.
 243         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 244
 245         // We store two local commitment transactions to avoid any race conditions where we may update
 246         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 247         // various monitors for one channel being out of sync, and us broadcasting a local
 248         // transaction for which we have deleted claim information on some watchtowers.
 249         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 250         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 251
 252         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 253
 254         destination_script: Script,
 255         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 256 }
 257 impl Clone for ChannelMonitor {
 258         fn clone(&self) -> Self {
 259                 ChannelMonitor {
 260                         funding_txo: self.funding_txo.clone(),
 261                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 262
 263                         key_storage: self.key_storage.clone(),
 264                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 265                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 266                         their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
 267                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 268
 269                         our_to_self_delay: self.our_to_self_delay,
 270                         their_to_self_delay: self.their_to_self_delay,
 271
 272                         old_secrets: self.old_secrets.clone(),
 273                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 274                         remote_commitment_txn_on_chain: Mutex::new((*self.remote_commitment_txn_on_chain.lock().unwrap()).clone()),
 275                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 276
 277                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 278                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 279
 280                         payment_preimages: self.payment_preimages.clone(),
 281
 282                         destination_script: self.destination_script.clone(),
 283                         secp_ctx: self.secp_ctx.clone(),
 284                 }
 285         }
 286 }
 287
 288 #[cfg(any(test, feature = "fuzztarget"))]
 289 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 290 /// underlying object
 291 impl PartialEq for ChannelMonitor {
 292         fn eq(&self, other: &Self) -> bool {
 293                 if self.funding_txo != other.funding_txo ||
 294                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 295                         self.key_storage != other.key_storage ||
 296                         self.delayed_payment_base_key != other.delayed_payment_base_key ||
 297                         self.their_htlc_base_key != other.their_htlc_base_key ||
 298                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 299                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 300                         self.our_to_self_delay != other.our_to_self_delay ||
 301                         self.their_to_self_delay != other.their_to_self_delay ||
 302                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 303                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 304                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 305                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 306                         self.payment_preimages != other.payment_preimages ||
 307                         self.destination_script != other.destination_script
 308                 {
 309                         false
 310                 } else {
 311                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 312                                 if secret != o_secret || idx != o_idx {
 313                                         return false
 314                                 }
 315                         }
 316                         let us = self.remote_commitment_txn_on_chain.lock().unwrap();
 317                         let them = other.remote_commitment_txn_on_chain.lock().unwrap();
 318                         *us == *them
 319                 }
 320         }
 321 }
 322
 323 impl ChannelMonitor {
 324         pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
 325                 ChannelMonitor {
 326                         funding_txo: None,
 327                         commitment_transaction_number_obscure_factor: 0,
 328
 329                         key_storage: KeyStorage::PrivMode {
 330                                 revocation_base_key: revocation_base_key.clone(),
 331                                 htlc_base_key: htlc_base_key.clone(),
 332                         },
 333                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 334                         their_htlc_base_key: None,
 335                         their_delayed_payment_base_key: None,
 336                         their_cur_revocation_points: None,
 337
 338                         our_to_self_delay: our_to_self_delay,
 339                         their_to_self_delay: None,
 340
 341                         old_secrets: [([0; 32], 1 << 48); 49],
 342                         remote_claimable_outpoints: HashMap::new(),
 343                         remote_commitment_txn_on_chain: Mutex::new(HashMap::new()),
 344                         remote_hash_commitment_number: HashMap::new(),
 345
 346                         prev_local_signed_commitment_tx: None,
 347                         current_local_signed_commitment_tx: None,
 348
 349                         payment_preimages: HashMap::new(),
 350
 351                         destination_script: destination_script,
 352                         secp_ctx: Secp256k1::new(),
 353                 }
 354         }
 355
 356         #[inline]
 357         fn place_secret(idx: u64) -> u8 {
 358                 for i in 0..48 {
 359                         if idx & (1 << i) == (1 << i) {
 360                                 return i
 361                         }
 362                 }
 363                 48
 364         }
 365
 366         #[inline]
 367         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 368                 let mut res: [u8; 32] = secret;
 369                 for i in 0..bits {
 370                         let bitpos = bits - 1 - i;
 371                         if idx & (1 << bitpos) == (1 << bitpos) {
 372                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 373                                 let mut sha = Sha256::new();
 374                                 sha.input(&res);
 375                                 sha.result(&mut res);
 376                         }
 377                 }
 378                 res
 379         }
 380
 381         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 382         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 383         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 384         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 385         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 386         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 387                 let pos = ChannelMonitor::place_secret(idx);
 388                 for i in 0..pos {
 389                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 390                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 391                                 return Err(HandleError{err: "Previous secret did not match new one", action: None})
 392                         }
 393                 }
 394                 self.old_secrets[pos as usize] = (secret, idx);
 395
 396                 if let Some(new_revocation_point) = their_next_revocation_point {
 397                         match self.their_cur_revocation_points {
 398                                 Some(old_points) => {
 399                                         if old_points.0 == new_revocation_point.0 + 1 {
 400                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 401                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 402                                                 if let Some(old_second_point) = old_points.2 {
 403                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 404                                                 } else {
 405                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 406                                                 }
 407                                         } else {
 408                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 409                                         }
 410                                 },
 411                                 None => {
 412                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 413                                 }
 414                         }
 415                 }
 416
 417                 if !self.payment_preimages.is_empty() {
 418                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 419                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 420                         let min_idx = self.get_min_seen_secret();
 421                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 422
 423                         self.payment_preimages.retain(|&k, _| {
 424                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 425                                         if k == htlc.payment_hash {
 426                                                 return true
 427                                         }
 428                                 }
 429                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 430                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 431                                                 if k == htlc.payment_hash {
 432                                                         return true
 433                                                 }
 434                                         }
 435                                 }
 436                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 437                                         if *cn < min_idx {
 438                                                 return true
 439                                         }
 440                                         true
 441                                 } else { false };
 442                                 if contains {
 443                                         remote_hash_commitment_number.remove(&k);
 444                                 }
 445                                 false
 446                         });
 447                 }
 448
 449                 Ok(())
 450         }
 451
 452         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 453         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 454         /// possibly future revocation/preimage information) to claim outputs where possible.
 455         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 456         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 457                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 458                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 459                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 460                 // timeouts)
 461                 for htlc in &htlc_outputs {
 462                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 463                 }
 464                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 465         }
 466
 467         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 468         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 469         /// is important that any clones of this channel monitor (including remote clones) by kept
 470         /// up-to-date as our local commitment transaction is updated.
 471         /// Panics if set_their_to_self_delay has never been called.
 472         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)>) {
 473                 assert!(self.their_to_self_delay.is_some());
 474                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 475                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 476                         txid: signed_commitment_tx.txid(),
 477                         tx: signed_commitment_tx,
 478                         revocation_key: local_keys.revocation_key,
 479                         a_htlc_key: local_keys.a_htlc_key,
 480                         b_htlc_key: local_keys.b_htlc_key,
 481                         delayed_payment_key: local_keys.a_delayed_payment_key,
 482                         feerate_per_kw,
 483                         htlc_outputs,
 484                 });
 485         }
 486
 487         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 488         /// commitment_tx_infos which contain the payment hash have been revoked.
 489         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 490                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 491         }
 492
 493         /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
 494         /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
 495         /// chain for new blocks/transactions.
 496         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 497                 if self.funding_txo.is_some() {
 498                         // We should be able to compare the entire funding_txo, but in fuzztarget its trivially
 499                         // easy to collide the funding_txo hash and have a different scriptPubKey.
 500                         if other.funding_txo.is_some() && other.funding_txo.as_ref().unwrap().0 != self.funding_txo.as_ref().unwrap().0 {
 501                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", action: None});
 502                         }
 503                 } else {
 504                         self.funding_txo = other.funding_txo.take();
 505                 }
 506                 let other_min_secret = other.get_min_seen_secret();
 507                 let our_min_secret = self.get_min_seen_secret();
 508                 if our_min_secret > other_min_secret {
 509                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 510                 }
 511                 if our_min_secret >= other_min_secret {
 512                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 513                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 514                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 515                         }
 516                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 517                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 518                         }
 519                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 520                                 self.current_local_signed_commitment_tx = Some(local_tx);
 521                         }
 522                         self.payment_preimages = other.payment_preimages;
 523                 }
 524                 Ok(())
 525         }
 526
 527         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 528         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 529                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 530                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 531         }
 532
 533         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 534         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 535         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 536         /// provides slightly better privacy.
 537         /// It's the responsibility of the caller to register outpoint and script with passing the former
 538         /// value as key to add_update_monitor.
 539         pub(super) fn set_funding_info(&mut self, funding_info: (OutPoint, Script)) {
 540                 self.funding_txo = Some(funding_info);
 541         }
 542
 543         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
 544         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
 545                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 546                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
 547         }
 548
 549         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 550                 self.their_to_self_delay = Some(their_to_self_delay);
 551         }
 552
 553         pub(super) fn unset_funding_info(&mut self) {
 554                 self.funding_txo = None;
 555         }
 556
 557         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
 558         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 559                 match self.funding_txo {
 560                         Some((outpoint, _)) => Some(outpoint),
 561                         None => None
 562                 }
 563         }
 564
 565         /// Serializes into a vec, with various modes for the exposed pub fns
 566         fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
 567                 //TODO: We still write out all the serialization here manually instead of using the fancy
 568                 //serialization framework we have, we should migrate things over to it.
 569                 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
 570                 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
 571
 572                 match &self.funding_txo {
 573                         &Some((ref outpoint, ref script)) => {
 574                                 writer.write_all(&outpoint.txid[..])?;
 575                                 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
 576                                 writer.write_all(&byte_utils::be64_to_array(script.len() as u64))?;
 577                                 writer.write_all(&script[..])?;
 578                         },
 579                         &None => {
 580                                 // We haven't even been initialized...not sure why anyone is serializing us, but
 581                                 // not much to give them.
 582                                 return Ok(());
 583                         },
 584                 }
 585
 586                 // Set in initial Channel-object creation, so should always be set by now:
 587                 writer.write_all(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor))?;
 588
 589                 match self.key_storage {
 590                         KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 591                                 writer.write_all(&[0; 1])?;
 592                                 writer.write_all(&revocation_base_key[..])?;
 593                                 writer.write_all(&htlc_base_key[..])?;
 594                         },
 595                         KeyStorage::SigsMode { .. } => unimplemented!(),
 596                 }
 597
 598                 writer.write_all(&self.delayed_payment_base_key.serialize())?;
 599                 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
 600                 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
 601
 602                 match self.their_cur_revocation_points {
 603                         Some((idx, pubkey, second_option)) => {
 604                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
 605                                 writer.write_all(&pubkey.serialize())?;
 606                                 match second_option {
 607                                         Some(second_pubkey) => {
 608                                                 writer.write_all(&second_pubkey.serialize())?;
 609                                         },
 610                                         None => {
 611                                                 writer.write_all(&[0; 33])?;
 612                                         },
 613                                 }
 614                         },
 615                         None => {
 616                                 writer.write_all(&byte_utils::be48_to_array(0))?;
 617                         },
 618                 }
 619
 620                 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
 621                 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
 622
 623                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 624                         writer.write_all(secret)?;
 625                         writer.write_all(&byte_utils::be64_to_array(*idx))?;
 626                 }
 627
 628                 macro_rules! serialize_htlc_in_commitment {
 629                         ($htlc_output: expr) => {
 630                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
 631                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
 632                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
 633                                 writer.write_all(&$htlc_output.payment_hash)?;
 634                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.transaction_output_index))?;
 635                         }
 636                 }
 637
 638                 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
 639                 for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
 640                         writer.write_all(&txid[..])?;
 641                         writer.write_all(&byte_utils::be64_to_array(htlc_outputs.len() as u64))?;
 642                         for htlc_output in htlc_outputs.iter() {
 643                                 serialize_htlc_in_commitment!(htlc_output);
 644                         }
 645                 }
 646
 647                 {
 648                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
 649                         writer.write_all(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64))?;
 650                         for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
 651                                 writer.write_all(&txid[..])?;
 652                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
 653                         }
 654                 }
 655
 656                 if for_local_storage {
 657                         writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
 658                         for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 659                                 writer.write_all(payment_hash)?;
 660                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
 661                         }
 662                 } else {
 663                         writer.write_all(&byte_utils::be64_to_array(0))?;
 664                 }
 665
 666                 macro_rules! serialize_local_tx {
 667                         ($local_tx: expr) => {
 668                                 let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
 669                                 writer.write_all(&byte_utils::be64_to_array(tx_ser.len() as u64))?;
 670                                 writer.write_all(&tx_ser)?;
 671
 672                                 writer.write_all(&$local_tx.revocation_key.serialize())?;
 673                                 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
 674                                 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
 675                                 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
 676
 677                                 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
 678                                 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
 679                                 for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
 680                                         serialize_htlc_in_commitment!(htlc_output);
 681                                         writer.write_all(&their_sig.serialize_compact(&self.secp_ctx))?;
 682                                         writer.write_all(&our_sig.serialize_compact(&self.secp_ctx))?;
 683                                 }
 684                         }
 685                 }
 686
 687                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 688                         writer.write_all(&[1; 1])?;
 689                         serialize_local_tx!(prev_local_tx);
 690                 } else {
 691                         writer.write_all(&[0; 1])?;
 692                 }
 693
 694                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 695                         writer.write_all(&[1; 1])?;
 696                         serialize_local_tx!(cur_local_tx);
 697                 } else {
 698                         writer.write_all(&[0; 1])?;
 699                 }
 700
 701                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
 702                 for payment_preimage in self.payment_preimages.values() {
 703                         writer.write_all(payment_preimage)?;
 704                 }
 705
 706                 writer.write_all(&byte_utils::be64_to_array(self.destination_script.len() as u64))?;
 707                 writer.write_all(&self.destination_script[..])?;
 708
 709                 Ok(())
 710         }
 711
 712         /// Writes this monitor into the given writer, suitable for writing to disk.
 713         pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 714                 self.write(writer, true)
 715         }
 716
 717         /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
 718         pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 719                 self.write(writer, false)
 720         }
 721
 722         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 723         //we want to leave out (eg funding_txo, etc).
 724
 725         /// Can only fail if idx is < get_min_seen_secret
 726         pub(super) fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 727                 for i in 0..self.old_secrets.len() {
 728                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 729                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 730                         }
 731                 }
 732                 assert!(idx < self.get_min_seen_secret());
 733                 Err(HandleError{err: "idx too low", action: None})
 734         }
 735
 736         pub(super) fn get_min_seen_secret(&self) -> u64 {
 737                 //TODO This can be optimized?
 738                 let mut min = 1 << 48;
 739                 for &(_, idx) in self.old_secrets.iter() {
 740                         if idx < min {
 741                                 min = idx;
 742                         }
 743                 }
 744                 min
 745         }
 746
 747         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 748         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 749         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 750         /// HTLC-Success/HTLC-Timeout transactions.
 751         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
 752                 // Most secp and related errors trying to create keys means we have no hope of constructing
 753                 // a spend transaction...so we return no transactions to broadcast
 754                 let mut txn_to_broadcast = Vec::new();
 755                 let mut watch_outputs = Vec::new();
 756
 757                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 758                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 759
 760                 macro_rules! ignore_error {
 761                         ( $thing : expr ) => {
 762                                 match $thing {
 763                                         Ok(a) => a,
 764                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs))
 765                                 }
 766                         };
 767                 }
 768
 769                 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);
 770                 if commitment_number >= self.get_min_seen_secret() {
 771                         let secret = self.get_secret(commitment_number).unwrap();
 772                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 773                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 774                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 775                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 776                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 777                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 778                                 },
 779                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 780                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 781                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 782                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 783                                 },
 784                         };
 785                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
 786                         let a_htlc_key = match self.their_htlc_base_key {
 787                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 788                                 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)),
 789                         };
 790
 791                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 792                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 793
 794                         let mut total_value = 0;
 795                         let mut values = Vec::new();
 796                         let mut inputs = Vec::new();
 797                         let mut htlc_idxs = Vec::new();
 798
 799                         for (idx, outp) in tx.output.iter().enumerate() {
 800                                 if outp.script_pubkey == revokeable_p2wsh {
 801                                         inputs.push(TxIn {
 802                                                 previous_output: BitcoinOutPoint {
 803                                                         txid: commitment_txid,
 804                                                         vout: idx as u32,
 805                                                 },
 806                                                 script_sig: Script::new(),
 807                                                 sequence: 0xfffffffd,
 808                                                 witness: Vec::new(),
 809                                         });
 810                                         htlc_idxs.push(None);
 811                                         values.push(outp.value);
 812                                         total_value += outp.value;
 813                                         break; // There can only be one of these
 814                                 }
 815                         }
 816
 817                         macro_rules! sign_input {
 818                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 819                                         {
 820                                                 let (sig, redeemscript) = match self.key_storage {
 821                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
 822                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
 823                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
 824                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
 825                                                                 };
 826                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 827                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
 828                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
 829                                                         },
 830                                                         KeyStorage::SigsMode { .. } => {
 831                                                                 unimplemented!();
 832                                                         }
 833                                                 };
 834                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 835                                                 $input.witness[0].push(SigHashType::All as u8);
 836                                                 if $htlc_idx.is_none() {
 837                                                         $input.witness.push(vec!(1));
 838                                                 } else {
 839                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
 840                                                 }
 841                                                 $input.witness.push(redeemscript.into_bytes());
 842                                         }
 843                                 }
 844                         }
 845
 846                         if let Some(per_commitment_data) = per_commitment_option {
 847                                 inputs.reserve_exact(per_commitment_data.len());
 848
 849                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
 850                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 851                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
 852                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
 853                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
 854                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
 855                                         }
 856                                         let input = TxIn {
 857                                                 previous_output: BitcoinOutPoint {
 858                                                         txid: commitment_txid,
 859                                                         vout: htlc.transaction_output_index,
 860                                                 },
 861                                                 script_sig: Script::new(),
 862                                                 sequence: 0xfffffffd,
 863                                                 witness: Vec::new(),
 864                                         };
 865                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 866                                                 inputs.push(input);
 867                                                 htlc_idxs.push(Some(idx));
 868                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
 869                                                 total_value += htlc.amount_msat / 1000;
 870                                         } else {
 871                                                 let mut single_htlc_tx = Transaction {
 872                                                         version: 2,
 873                                                         lock_time: 0,
 874                                                         input: vec![input],
 875                                                         output: vec!(TxOut {
 876                                                                 script_pubkey: self.destination_script.clone(),
 877                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 878                                                         }),
 879                                                 };
 880                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
 881                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
 882                                                 txn_to_broadcast.push(single_htlc_tx);
 883                                         }
 884                                 }
 885                         }
 886
 887                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours
 888                                 // We're definitely a remote commitment transaction!
 889                                 watch_outputs.append(&mut tx.output.clone());
 890                                 self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
 891                         }
 892                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
 893
 894                         let outputs = vec!(TxOut {
 895                                 script_pubkey: self.destination_script.clone(),
 896                                 value: total_value, //TODO: - fee
 897                         });
 898                         let mut spend_tx = Transaction {
 899                                 version: 2,
 900                                 lock_time: 0,
 901                                 input: inputs,
 902                                 output: outputs,
 903                         };
 904
 905                         let mut values_drain = values.drain(..);
 906                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 907
 908                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
 909                                 let value = values_drain.next().unwrap();
 910                                 sign_input!(sighash_parts, input, htlc_idx, value);
 911                         }
 912
 913                         txn_to_broadcast.push(spend_tx);
 914                 } else if let Some(per_commitment_data) = per_commitment_option {
 915                         // While this isn't useful yet, there is a potential race where if a counterparty
 916                         // revokes a state at the same time as the commitment transaction for that state is
 917                         // confirmed, and the watchtower receives the block before the user, the user could
 918                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
 919                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
 920                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
 921                         // insert it here.
 922                         watch_outputs.append(&mut tx.output.clone());
 923                         self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
 924
 925                         if let Some(revocation_points) = self.their_cur_revocation_points {
 926                                 let revocation_point_option =
 927                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
 928                                         else if let Some(point) = revocation_points.2.as_ref() {
 929                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
 930                                         } else { None };
 931                                 if let Some(revocation_point) = revocation_point_option {
 932                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 933                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 934                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 935                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 936                                                 },
 937                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 938                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
 939                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
 940                                                 },
 941                                         };
 942                                         let a_htlc_key = match self.their_htlc_base_key {
 943                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 944                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
 945                                         };
 946
 947                                         let mut total_value = 0;
 948                                         let mut values = Vec::new();
 949                                         let mut inputs = Vec::new();
 950
 951                                         macro_rules! sign_input {
 952                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
 953                                                         {
 954                                                                 let (sig, redeemscript) = match self.key_storage {
 955                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
 956                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
 957                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 958                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 959                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
 960                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
 961                                                                         },
 962                                                                         KeyStorage::SigsMode { .. } => {
 963                                                                                 unimplemented!();
 964                                                                         }
 965                                                                 };
 966                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 967                                                                 $input.witness[0].push(SigHashType::All as u8);
 968                                                                 $input.witness.push($preimage);
 969                                                                 $input.witness.push(redeemscript.into_bytes());
 970                                                         }
 971                                                 }
 972                                         }
 973
 974                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
 975                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
 976                                                         let input = TxIn {
 977                                                                 previous_output: BitcoinOutPoint {
 978                                                                         txid: commitment_txid,
 979                                                                         vout: htlc.transaction_output_index,
 980                                                                 },
 981                                                                 script_sig: Script::new(),
 982                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
 983                                                                 witness: Vec::new(),
 984                                                         };
 985                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 986                                                                 inputs.push(input);
 987                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
 988                                                                 total_value += htlc.amount_msat / 1000;
 989                                                         } else {
 990                                                                 let mut single_htlc_tx = Transaction {
 991                                                                         version: 2,
 992                                                                         lock_time: 0,
 993                                                                         input: vec![input],
 994                                                                         output: vec!(TxOut {
 995                                                                                 script_pubkey: self.destination_script.clone(),
 996                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 997                                                                         }),
 998                                                                 };
 999                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1000                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
1001                                                                 txn_to_broadcast.push(single_htlc_tx);
1002                                                         }
1003                                                 }
1004                                         }
1005
1006                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
1007
1008                                         let outputs = vec!(TxOut {
1009                                                 script_pubkey: self.destination_script.clone(),
1010                                                 value: total_value, //TODO: - fee
1011                                         });
1012                                         let mut spend_tx = Transaction {
1013                                                 version: 2,
1014                                                 lock_time: 0,
1015                                                 input: inputs,
1016                                                 output: outputs,
1017                                         };
1018
1019                                         let mut values_drain = values.drain(..);
1020                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1021
1022                                         for input in spend_tx.input.iter_mut() {
1023                                                 let value = values_drain.next().unwrap();
1024                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
1025                                         }
1026
1027                                         txn_to_broadcast.push(spend_tx);
1028                                 }
1029                         }
1030                 }
1031
1032                 (txn_to_broadcast, (commitment_txid, watch_outputs))
1033         }
1034
1035         /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
1036         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
1037                 if tx.input.len() != 1 || tx.output.len() != 1 {
1038                         return None;
1039                 }
1040
1041                 macro_rules! ignore_error {
1042                         ( $thing : expr ) => {
1043                                 match $thing {
1044                                         Ok(a) => a,
1045                                         Err(_) => return None
1046                                 }
1047                         };
1048                 }
1049
1050                 let secret = ignore_error!(self.get_secret(commitment_number));
1051                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
1052                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1053                 let revocation_pubkey = match self.key_storage {
1054                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1055                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1056                         },
1057                         KeyStorage::SigsMode { ref revocation_base_key, .. } => {
1058                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
1059                         },
1060                 };
1061                 let delayed_key = match self.their_delayed_payment_base_key {
1062                         None => return None,
1063                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1064                 };
1065                 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
1066                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1067                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1068
1069                 let mut inputs = Vec::new();
1070                 let mut amount = 0;
1071
1072                 if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
1073                         inputs.push(TxIn {
1074                                 previous_output: BitcoinOutPoint {
1075                                         txid: htlc_txid,
1076                                         vout: 0,
1077                                 },
1078                                 script_sig: Script::new(),
1079                                 sequence: 0xfffffffd,
1080                                 witness: Vec::new(),
1081                         });
1082                         amount = tx.output[0].value;
1083                 }
1084
1085                 if !inputs.is_empty() {
1086                         let outputs = vec!(TxOut {
1087                                 script_pubkey: self.destination_script.clone(),
1088                                 value: amount, //TODO: - fee
1089                         });
1090
1091                         let mut spend_tx = Transaction {
1092                                 version: 2,
1093                                 lock_time: 0,
1094                                 input: inputs,
1095                                 output: outputs,
1096                         };
1097
1098                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1099
1100                         let sig = match self.key_storage {
1101                                 KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1102                                         let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]));
1103                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1104                                         self.secp_ctx.sign(&sighash, &revocation_key)
1105                                 }
1106                                 KeyStorage::SigsMode { .. } => {
1107                                         unimplemented!();
1108                                 }
1109                         };
1110                         spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1111                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1112                         spend_tx.input[0].witness.push(vec!(1));
1113                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1114
1115                         Some(spend_tx)
1116                 } else { None }
1117         }
1118
1119         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
1120                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1121
1122                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
1123                         if htlc.offered {
1124                                 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);
1125
1126                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1127
1128                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1129                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1130                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1131                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1132
1133                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1134                                 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());
1135
1136                                 res.push(htlc_timeout_tx);
1137                         } else {
1138                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1139                                         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);
1140
1141                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1142
1143                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1144                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1145                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1146                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1147
1148                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
1149                                         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());
1150
1151                                         res.push(htlc_success_tx);
1152                                 }
1153                         }
1154                 }
1155
1156                 res
1157         }
1158
1159         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1160         /// revoked using data in local_claimable_outpoints.
1161         /// Should not be used if check_spend_revoked_transaction succeeds.
1162         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
1163                 let commitment_txid = tx.txid();
1164                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1165                         if local_tx.txid == commitment_txid {
1166                                 return self.broadcast_by_local_state(local_tx);
1167                         }
1168                 }
1169                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1170                         if local_tx.txid == commitment_txid {
1171                                 return self.broadcast_by_local_state(local_tx);
1172                         }
1173                 }
1174                 Vec::new()
1175         }
1176
1177         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
1178                 let mut watch_outputs = Vec::new();
1179                 for tx in txn_matched {
1180                         if tx.input.len() == 1 {
1181                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1182                                 // commitment transactions and HTLC transactions will all only ever have one input,
1183                                 // which is an easy way to filter out any potential non-matching txn for lazy
1184                                 // filters.
1185                                 let prevout = &tx.input[0].previous_output;
1186                                 let mut txn: Vec<Transaction> = Vec::new();
1187                                 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) {
1188                                         let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
1189                                         txn = remote_txn;
1190                                         if !new_outputs.1.is_empty() {
1191                                                 watch_outputs.push(new_outputs);
1192                                         }
1193                                         if txn.is_empty() {
1194                                                 txn = self.check_spend_local_transaction(tx, height);
1195                                         }
1196                                 } else {
1197                                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
1198                                         if let Some(commitment_number) = remote_commitment_txn_on_chain.get(&prevout.txid) {
1199                                                 if let Some(tx) = self.check_spend_remote_htlc(tx, *commitment_number) {
1200                                                         txn.push(tx);
1201                                                 }
1202                                         }
1203                                 }
1204                                 for tx in txn.iter() {
1205                                         broadcaster.broadcast_transaction(tx);
1206                                 }
1207                         }
1208                 }
1209                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1210                         if self.would_broadcast_at_height(height) {
1211                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1212                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
1213                                         broadcaster.broadcast_transaction(&tx);
1214                                 }
1215                         }
1216                 }
1217                 watch_outputs
1218         }
1219
1220         pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
1221                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1222                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1223                                 // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1224                                 // chain with enough room to claim the HTLC without our counterparty being able to
1225                                 // time out the HTLC first.
1226                                 // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1227                                 // concern is being able to claim the corresponding inbound HTLC (on another
1228                                 // channel) before it expires. In fact, we don't even really care if our
1229                                 // counterparty here claims such an outbound HTLC after it expired as long as we
1230                                 // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
1231                                 // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
1232                                 // we give ourselves a few blocks of headroom after expiration before going
1233                                 // on-chain for an expired HTLC.
1234                                 // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
1235                                 // from us until we've reached the point where we go on-chain with the
1236                                 // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
1237                                 // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
1238                                 //  aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
1239                                 //      inbound_cltv == height + CLTV_CLAIM_BUFFER
1240                                 //      outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFER <= inbound_cltv - CLTV_CLAIM_BUFFER
1241                                 //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= inbound_cltv - outbound_cltv
1242                                 //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFER <= CLTV_EXPIRY_DELTA
1243                                 if ( htlc.offered && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
1244                                    (!htlc.offered && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
1245                                         return true;
1246                                 }
1247                         }
1248                 }
1249                 false
1250         }
1251 }
1252
1253 impl<R: ::std::io::Read> Readable<R> for ChannelMonitor {
1254         fn read(reader: &mut R) -> Result<Self, DecodeError> {
1255                 // TODO: read_to_end and then deserializing from that vector is really dumb, we should
1256                 // actually use the fancy serialization framework we have instead of hacking around it.
1257                 let mut datavec = Vec::new();
1258                 reader.read_to_end(&mut datavec)?;
1259                 let data = &datavec;
1260
1261                 let mut read_pos = 0;
1262                 macro_rules! read_bytes {
1263                         ($byte_count: expr) => {
1264                                 {
1265                                         if ($byte_count as usize) > data.len() - read_pos {
1266                                                 return Err(DecodeError::ShortRead);
1267                                         }
1268                                         read_pos += $byte_count as usize;
1269                                         &data[read_pos - $byte_count as usize..read_pos]
1270                                 }
1271                         }
1272                 }
1273
1274                 let secp_ctx = Secp256k1::new();
1275                 macro_rules! unwrap_obj {
1276                         ($key: expr) => {
1277                                 match $key {
1278                                         Ok(res) => res,
1279                                         Err(_) => return Err(DecodeError::InvalidValue),
1280                                 }
1281                         }
1282                 }
1283
1284                 let _ver = read_bytes!(1)[0];
1285                 let min_ver = read_bytes!(1)[0];
1286                 if min_ver > SERIALIZATION_VERSION {
1287                         return Err(DecodeError::UnknownVersion);
1288                 }
1289
1290                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
1291                 // barely-init'd ChannelMonitors that we can't do anything with.
1292                 let outpoint = OutPoint {
1293                         txid: Sha256dHash::from(read_bytes!(32)),
1294                         index: byte_utils::slice_to_be16(read_bytes!(2)),
1295                 };
1296                 let script_len = byte_utils::slice_to_be64(read_bytes!(8));
1297                 let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
1298                 let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
1299
1300                 let key_storage = match read_bytes!(1)[0] {
1301                         0 => {
1302                                 KeyStorage::PrivMode {
1303                                         revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
1304                                         htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
1305                                 }
1306                         },
1307                         _ => return Err(DecodeError::InvalidValue),
1308                 };
1309
1310                 let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1311                 let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
1312                 let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
1313
1314                 let their_cur_revocation_points = {
1315                         let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
1316                         if first_idx == 0 {
1317                                 None
1318                         } else {
1319                                 let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1320                                 let second_point_slice = read_bytes!(33);
1321                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
1322                                         Some((first_idx, first_point, None))
1323                                 } else {
1324                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
1325                                 }
1326                         }
1327                 };
1328
1329                 let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
1330                 let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
1331
1332                 let mut old_secrets = [([0; 32], 1 << 48); 49];
1333                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
1334                         secret.copy_from_slice(read_bytes!(32));
1335                         *idx = byte_utils::slice_to_be64(read_bytes!(8));
1336                 }
1337
1338                 macro_rules! read_htlc_in_commitment {
1339                         () => {
1340                                 {
1341                                         let offered = match read_bytes!(1)[0] {
1342                                                 0 => false, 1 => true,
1343                                                 _ => return Err(DecodeError::InvalidValue),
1344                                         };
1345                                         let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
1346                                         let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
1347                                         let mut payment_hash = [0; 32];
1348                                         payment_hash[..].copy_from_slice(read_bytes!(32));
1349                                         let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
1350
1351                                         HTLCOutputInCommitment {
1352                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
1353                                         }
1354                                 }
1355                         }
1356                 }
1357
1358                 let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
1359                 if remote_claimable_outpoints_len > data.len() as u64 / 64 { return Err(DecodeError::BadLengthDescriptor); }
1360                 let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
1361                 for _ in 0..remote_claimable_outpoints_len {
1362                         let txid = Sha256dHash::from(read_bytes!(32));
1363                         let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
1364                         if outputs_count > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1365                         let mut outputs = Vec::with_capacity(outputs_count as usize);
1366                         for _ in 0..outputs_count {
1367                                 outputs.push(read_htlc_in_commitment!());
1368                         }
1369                         if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
1370                                 return Err(DecodeError::InvalidValue);
1371                         }
1372                 }
1373
1374                 let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
1375                 if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1376                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
1377                 for _ in 0..remote_commitment_txn_on_chain_len {
1378                         let txid = Sha256dHash::from(read_bytes!(32));
1379                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
1380                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
1381                                 return Err(DecodeError::InvalidValue);
1382                         }
1383                 }
1384
1385                 let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
1386                 if remote_hash_commitment_number_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1387                 let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
1388                 for _ in 0..remote_hash_commitment_number_len {
1389                         let mut txid = [0; 32];
1390                         txid[..].copy_from_slice(read_bytes!(32));
1391                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
1392                         if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
1393                                 return Err(DecodeError::InvalidValue);
1394                         }
1395                 }
1396
1397                 macro_rules! read_local_tx {
1398                         () => {
1399                                 {
1400                                         let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
1401                                         let tx_ser = read_bytes!(tx_len);
1402                                         let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
1403                                         if serialize::serialize(&tx).unwrap() != tx_ser {
1404                                                 // We check that the tx re-serializes to the same form to ensure there is
1405                                                 // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
1406                                                 // all that well.
1407                                                 return Err(DecodeError::InvalidValue);
1408                                         }
1409
1410                                         let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1411                                         let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1412                                         let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1413                                         let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1414                                         let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
1415
1416                                         let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
1417                                         if htlc_outputs_len > data.len() as u64 / 128 { return Err(DecodeError::BadLengthDescriptor); }
1418                                         let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
1419                                         for _ in 0..htlc_outputs_len {
1420                                                 htlc_outputs.push((read_htlc_in_commitment!(),
1421                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
1422                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
1423                                         }
1424
1425                                         LocalSignedTx {
1426                                                 txid: tx.txid(),
1427                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
1428                                         }
1429                                 }
1430                         }
1431                 }
1432
1433                 let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
1434                         0 => None,
1435                         1 => {
1436                                 Some(read_local_tx!())
1437                         },
1438                         _ => return Err(DecodeError::InvalidValue),
1439                 };
1440
1441                 let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
1442                         0 => None,
1443                         1 => {
1444                                 Some(read_local_tx!())
1445                         },
1446                         _ => return Err(DecodeError::InvalidValue),
1447                 };
1448
1449                 let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
1450                 if payment_preimages_len > data.len() as u64 / 32 { return Err(DecodeError::InvalidValue); }
1451                 let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
1452                 let mut sha = Sha256::new();
1453                 for _ in 0..payment_preimages_len {
1454                         let mut preimage = [0; 32];
1455                         preimage[..].copy_from_slice(read_bytes!(32));
1456                         sha.reset();
1457                         sha.input(&preimage);
1458                         let mut hash = [0; 32];
1459                         sha.result(&mut hash);
1460                         if let Some(_) = payment_preimages.insert(hash, preimage) {
1461                                 return Err(DecodeError::InvalidValue);
1462                         }
1463                 }
1464
1465                 let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
1466                 let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
1467
1468                 Ok(ChannelMonitor {
1469                         funding_txo,
1470                         commitment_transaction_number_obscure_factor,
1471
1472                         key_storage,
1473                         delayed_payment_base_key,
1474                         their_htlc_base_key,
1475                         their_delayed_payment_base_key,
1476                         their_cur_revocation_points,
1477
1478                         our_to_self_delay,
1479                         their_to_self_delay,
1480
1481                         old_secrets,
1482                         remote_claimable_outpoints,
1483                         remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
1484                         remote_hash_commitment_number,
1485
1486                         prev_local_signed_commitment_tx,
1487                         current_local_signed_commitment_tx,
1488
1489                         payment_preimages,
1490
1491                         destination_script,
1492                         secp_ctx,
1493                 })
1494         }
1495
1496 }
1497
1498 #[cfg(test)]
1499 mod tests {
1500         use bitcoin::blockdata::script::Script;
1501         use bitcoin::blockdata::transaction::Transaction;
1502         use crypto::digest::Digest;
1503         use hex;
1504         use ln::channelmonitor::ChannelMonitor;
1505         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
1506         use util::sha2::Sha256;
1507         use secp256k1::key::{SecretKey,PublicKey};
1508         use secp256k1::{Secp256k1, Signature};
1509         use rand::{thread_rng,Rng};
1510
1511         #[test]
1512         fn test_per_commitment_storage() {
1513                 // Test vectors from BOLT 3:
1514                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1515                 let mut monitor: ChannelMonitor;
1516                 let secp_ctx = Secp256k1::new();
1517
1518                 macro_rules! test_secrets {
1519                         () => {
1520                                 let mut idx = 281474976710655;
1521                                 for secret in secrets.iter() {
1522                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1523                                         idx -= 1;
1524                                 }
1525                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1526                                 assert!(monitor.get_secret(idx).is_err());
1527                         };
1528                 }
1529
1530                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1531
1532                 {
1533                         // insert_secret correct sequence
1534                         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());
1535                         secrets.clear();
1536
1537                         secrets.push([0; 32]);
1538                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1539                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1540                         test_secrets!();
1541
1542                         secrets.push([0; 32]);
1543                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1544                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1545                         test_secrets!();
1546
1547                         secrets.push([0; 32]);
1548                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1549                         monitor.provide_secret(281474976710653, 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("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1554                         monitor.provide_secret(281474976710652, 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("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1559                         monitor.provide_secret(281474976710651, 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("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1564                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1565                         test_secrets!();
1566
1567                         secrets.push([0; 32]);
1568                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1569                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1570                         test_secrets!();
1571
1572                         secrets.push([0; 32]);
1573                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1574                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
1575                         test_secrets!();
1576                 }
1577
1578                 {
1579                         // insert_secret #1 incorrect
1580                         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());
1581                         secrets.clear();
1582
1583                         secrets.push([0; 32]);
1584                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1585                         monitor.provide_secret(281474976710655, 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("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1590                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
1591                                         "Previous secret did not match new one");
1592                 }
1593
1594                 {
1595                         // insert_secret #2 incorrect (#1 derived from incorrect)
1596                         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());
1597                         secrets.clear();
1598
1599                         secrets.push([0; 32]);
1600                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1601                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1602                         test_secrets!();
1603
1604                         secrets.push([0; 32]);
1605                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1606                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1607                         test_secrets!();
1608
1609                         secrets.push([0; 32]);
1610                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1611                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1612                         test_secrets!();
1613
1614                         secrets.push([0; 32]);
1615                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1616                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1617                                         "Previous secret did not match new one");
1618                 }
1619
1620                 {
1621                         // insert_secret #3 incorrect
1622                         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());
1623                         secrets.clear();
1624
1625                         secrets.push([0; 32]);
1626                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1627                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1628                         test_secrets!();
1629
1630                         secrets.push([0; 32]);
1631                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1632                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1633                         test_secrets!();
1634
1635                         secrets.push([0; 32]);
1636                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1637                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1638                         test_secrets!();
1639
1640                         secrets.push([0; 32]);
1641                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1642                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1643                                         "Previous secret did not match new one");
1644                 }
1645
1646                 {
1647                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1648                         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());
1649                         secrets.clear();
1650
1651                         secrets.push([0; 32]);
1652                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1653                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1654                         test_secrets!();
1655
1656                         secrets.push([0; 32]);
1657                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1658                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1659                         test_secrets!();
1660
1661                         secrets.push([0; 32]);
1662                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1663                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1664                         test_secrets!();
1665
1666                         secrets.push([0; 32]);
1667                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1668                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1669                         test_secrets!();
1670
1671                         secrets.push([0; 32]);
1672                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1673                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1674                         test_secrets!();
1675
1676                         secrets.push([0; 32]);
1677                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1678                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1679                         test_secrets!();
1680
1681                         secrets.push([0; 32]);
1682                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1683                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1684                         test_secrets!();
1685
1686                         secrets.push([0; 32]);
1687                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1688                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1689                                         "Previous secret did not match new one");
1690                 }
1691
1692                 {
1693                         // insert_secret #5 incorrect
1694                         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());
1695                         secrets.clear();
1696
1697                         secrets.push([0; 32]);
1698                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1699                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1700                         test_secrets!();
1701
1702                         secrets.push([0; 32]);
1703                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1704                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1705                         test_secrets!();
1706
1707                         secrets.push([0; 32]);
1708                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1709                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1710                         test_secrets!();
1711
1712                         secrets.push([0; 32]);
1713                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1714                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1715                         test_secrets!();
1716
1717                         secrets.push([0; 32]);
1718                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1719                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1720                         test_secrets!();
1721
1722                         secrets.push([0; 32]);
1723                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1724                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1725                                         "Previous secret did not match new one");
1726                 }
1727
1728                 {
1729                         // insert_secret #6 incorrect (5 derived from incorrect)
1730                         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());
1731                         secrets.clear();
1732
1733                         secrets.push([0; 32]);
1734                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1735                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1736                         test_secrets!();
1737
1738                         secrets.push([0; 32]);
1739                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1740                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1741                         test_secrets!();
1742
1743                         secrets.push([0; 32]);
1744                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1745                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1746                         test_secrets!();
1747
1748                         secrets.push([0; 32]);
1749                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1750                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1751                         test_secrets!();
1752
1753                         secrets.push([0; 32]);
1754                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1755                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1756                         test_secrets!();
1757
1758                         secrets.push([0; 32]);
1759                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1760                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1761                         test_secrets!();
1762
1763                         secrets.push([0; 32]);
1764                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1765                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1766                         test_secrets!();
1767
1768                         secrets.push([0; 32]);
1769                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1770                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1771                                         "Previous secret did not match new one");
1772                 }
1773
1774                 {
1775                         // insert_secret #7 incorrect
1776                         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());
1777                         secrets.clear();
1778
1779                         secrets.push([0; 32]);
1780                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1781                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1782                         test_secrets!();
1783
1784                         secrets.push([0; 32]);
1785                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1786                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1787                         test_secrets!();
1788
1789                         secrets.push([0; 32]);
1790                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1791                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1792                         test_secrets!();
1793
1794                         secrets.push([0; 32]);
1795                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1796                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1797                         test_secrets!();
1798
1799                         secrets.push([0; 32]);
1800                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1801                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1802                         test_secrets!();
1803
1804                         secrets.push([0; 32]);
1805                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1806                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1807                         test_secrets!();
1808
1809                         secrets.push([0; 32]);
1810                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1811                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1812                         test_secrets!();
1813
1814                         secrets.push([0; 32]);
1815                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1816                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1817                                         "Previous secret did not match new one");
1818                 }
1819
1820                 {
1821                         // insert_secret #8 incorrect
1822                         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());
1823                         secrets.clear();
1824
1825                         secrets.push([0; 32]);
1826                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1827                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1828                         test_secrets!();
1829
1830                         secrets.push([0; 32]);
1831                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1832                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1833                         test_secrets!();
1834
1835                         secrets.push([0; 32]);
1836                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1837                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1838                         test_secrets!();
1839
1840                         secrets.push([0; 32]);
1841                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1842                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1843                         test_secrets!();
1844
1845                         secrets.push([0; 32]);
1846                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1847                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1848                         test_secrets!();
1849
1850                         secrets.push([0; 32]);
1851                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1852                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1853                         test_secrets!();
1854
1855                         secrets.push([0; 32]);
1856                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1857                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1858                         test_secrets!();
1859
1860                         secrets.push([0; 32]);
1861                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1862                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1863                                         "Previous secret did not match new one");
1864                 }
1865         }
1866
1867         #[test]
1868         fn test_prune_preimages() {
1869                 let secp_ctx = Secp256k1::new();
1870                 let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap();
1871
1872                 macro_rules! dummy_keys {
1873                         () => {
1874                                 {
1875                                         let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1876                                         TxCreationKeys {
1877                                                 per_commitment_point: dummy_key.clone(),
1878                                                 revocation_key: dummy_key.clone(),
1879                                                 a_htlc_key: dummy_key.clone(),
1880                                                 b_htlc_key: dummy_key.clone(),
1881                                                 a_delayed_payment_key: dummy_key.clone(),
1882                                                 b_payment_key: dummy_key.clone(),
1883                                         }
1884                                 }
1885                         }
1886                 }
1887                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
1888
1889                 let mut preimages = Vec::new();
1890                 {
1891                         let mut rng  = thread_rng();
1892                         for _ in 0..20 {
1893                                 let mut preimage = [0; 32];
1894                                 rng.fill_bytes(&mut preimage);
1895                                 let mut sha = Sha256::new();
1896                                 sha.input(&preimage);
1897                                 let mut hash = [0; 32];
1898                                 sha.result(&mut hash);
1899                                 preimages.push((preimage, hash));
1900                         }
1901                 }
1902
1903                 macro_rules! preimages_slice_to_htlc_outputs {
1904                         ($preimages_slice: expr) => {
1905                                 {
1906                                         let mut res = Vec::new();
1907                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
1908                                                 res.push(HTLCOutputInCommitment {
1909                                                         offered: true,
1910                                                         amount_msat: 0,
1911                                                         cltv_expiry: 0,
1912                                                         payment_hash: preimage.1.clone(),
1913                                                         transaction_output_index: idx as u32,
1914                                                 });
1915                                         }
1916                                         res
1917                                 }
1918                         }
1919                 }
1920                 macro_rules! preimages_to_local_htlcs {
1921                         ($preimages_slice: expr) => {
1922                                 {
1923                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
1924                                         let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect();
1925                                         res
1926                                 }
1927                         }
1928                 }
1929
1930                 macro_rules! test_preimages_exist {
1931                         ($preimages_slice: expr, $monitor: expr) => {
1932                                 for preimage in $preimages_slice {
1933                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
1934                                 }
1935                         }
1936                 }
1937
1938                 // Prune with one old state and a local commitment tx holding a few overlaps with the
1939                 // old state.
1940                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1941                 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());
1942                 monitor.set_their_to_self_delay(10);
1943
1944                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
1945                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655);
1946                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654);
1947                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653);
1948                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652);
1949                 for &(ref preimage, ref hash) in preimages.iter() {
1950                         monitor.provide_payment_preimage(hash, preimage);
1951                 }
1952
1953                 // Now provide a secret, pruning preimages 10-15
1954                 let mut secret = [0; 32];
1955                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1956                 monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1957                 assert_eq!(monitor.payment_preimages.len(), 15);
1958                 test_preimages_exist!(&preimages[0..10], monitor);
1959                 test_preimages_exist!(&preimages[15..20], monitor);
1960
1961                 // Now provide a further secret, pruning preimages 15-17
1962                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1963                 monitor.provide_secret(281474976710654, secret.clone(), None).unwrap();
1964                 assert_eq!(monitor.payment_preimages.len(), 13);
1965                 test_preimages_exist!(&preimages[0..10], monitor);
1966                 test_preimages_exist!(&preimages[17..20], monitor);
1967
1968                 // Now update local commitment tx info, pruning only element 18 as we still care about the
1969                 // previous commitment tx's preimages too
1970                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
1971                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1972                 monitor.provide_secret(281474976710653, secret.clone(), None).unwrap();
1973                 assert_eq!(monitor.payment_preimages.len(), 12);
1974                 test_preimages_exist!(&preimages[0..10], monitor);
1975                 test_preimages_exist!(&preimages[18..20], monitor);
1976
1977                 // But if we do it again, we'll prune 5-10
1978                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
1979                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1980                 monitor.provide_secret(281474976710652, secret.clone(), None).unwrap();
1981                 assert_eq!(monitor.payment_preimages.len(), 5);
1982                 test_preimages_exist!(&preimages[0..5], monitor);
1983         }
1984
1985         // Further testing is done in the ChannelManager integration tests.
1986 }