_ 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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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 pub enum ChannelMonitorUpdateErr {
  43         /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
  44         /// to succeed at some point in the future).
  45         ///
  46         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  47         /// submitting new commitment transactions to the remote party.
  48         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  49         /// the channel to an operational state.
  50         TemporaryFailure,
  51         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  52         /// different watchtower and cannot update with all watchtowers that were previously informed
  53         /// of this channel). This will force-close the channel in question.
  54         PermanentFailure,
  55 }
  56
  57 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
  58 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
  59 /// events to it, while also taking any add_update_monitor events and passing them to some remote
  60 /// server(s).
  61 ///
  62 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
  63 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
  64 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
  65 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
  66 pub trait ManyChannelMonitor: Send + Sync {
  67         /// Adds or updates a monitor for the given `funding_txo`.
  68         ///
  69         /// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
  70         /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
  71         /// any spends of it.
  72         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
  73 }
  74
  75 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
  76 /// watchtower or watch our own channels.
  77 ///
  78 /// Note that you must provide your own key by which to refer to channels.
  79 ///
  80 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
  81 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
  82 /// index by a PublicKey which is required to sign any updates.
  83 ///
  84 /// If you're using this for local monitoring of your own channels, you probably want to use
  85 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
  86 pub struct SimpleManyChannelMonitor<Key> {
  87         #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
  88         pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  89         #[cfg(not(test))]
  90         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  91         chain_monitor: Arc<ChainWatchInterface>,
  92         broadcaster: Arc<BroadcasterInterface>
  93 }
  94
  95 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
  96         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
  97                 let monitors = self.monitors.lock().unwrap();
  98                 for monitor in monitors.values() {
  99                         let txn_outputs = monitor.block_connected(txn_matched, height, &*self.broadcaster);
 100                         for (ref txid, ref outputs) in txn_outputs {
 101                                 for (idx, output) in outputs.iter().enumerate() {
 102                                         self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
 103                                 }
 104                         }
 105                 }
 106         }
 107
 108         fn block_disconnected(&self, _: &BlockHeader) { }
 109 }
 110
 111 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
 112         /// Creates a new object which can be used to monitor several channels given the chain
 113         /// interface with which to register to receive notifications.
 114         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
 115                 let res = Arc::new(SimpleManyChannelMonitor {
 116                         monitors: Mutex::new(HashMap::new()),
 117                         chain_monitor,
 118                         broadcaster
 119                 });
 120                 let weak_res = Arc::downgrade(&res);
 121                 res.chain_monitor.register_listener(weak_res);
 122                 res
 123         }
 124
 125         /// Adds or udpates the monitor which monitors the channel referred to by the given key.
 126         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
 127                 let mut monitors = self.monitors.lock().unwrap();
 128                 match monitors.get_mut(&key) {
 129                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
 130                         None => {}
 131                 };
 132                 match &monitor.funding_txo {
 133                         &None => self.chain_monitor.watch_all_txn(),
 134                         &Some((ref outpoint, ref script)) => {
 135                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
 136                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
 137                         },
 138                 }
 139                 monitors.insert(key, monitor);
 140                 Ok(())
 141         }
 142 }
 143
 144 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 145         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 146                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 147                         Ok(_) => Ok(()),
 148                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 149                 }
 150         }
 151 }
 152
 153 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 154 /// instead claiming it in its own individual transaction.
 155 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 156 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 157 /// HTLC-Success transaction.
 158 const CLTV_CLAIM_BUFFER: u32 = 6;
 159
 160 #[derive(Clone, PartialEq)]
 161 enum KeyStorage {
 162         PrivMode {
 163                 revocation_base_key: SecretKey,
 164                 htlc_base_key: SecretKey,
 165         },
 166         SigsMode {
 167                 revocation_base_key: PublicKey,
 168                 htlc_base_key: PublicKey,
 169                 sigs: HashMap<Sha256dHash, Signature>,
 170         }
 171 }
 172
 173 #[derive(Clone, PartialEq)]
 174 struct LocalSignedTx {
 175         /// txid of the transaction in tx, just used to make comparison faster
 176         txid: Sha256dHash,
 177         tx: Transaction,
 178         revocation_key: PublicKey,
 179         a_htlc_key: PublicKey,
 180         b_htlc_key: PublicKey,
 181         delayed_payment_key: PublicKey,
 182         feerate_per_kw: u64,
 183         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 184 }
 185
 186 const SERIALIZATION_VERSION: u8 = 1;
 187 const MIN_SERIALIZATION_VERSION: u8 = 1;
 188
 189 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
 190 /// on-chain transactions to ensure no loss of funds occurs.
 191 ///
 192 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
 193 /// information and are actively monitoring the chain.
 194 pub struct ChannelMonitor {
 195         funding_txo: Option<(OutPoint, Script)>,
 196         commitment_transaction_number_obscure_factor: u64,
 197
 198         key_storage: KeyStorage,
 199         delayed_payment_base_key: PublicKey,
 200         their_htlc_base_key: Option<PublicKey>,
 201         their_delayed_payment_base_key: Option<PublicKey>,
 202         // first is the idx of the first of the two revocation points
 203         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 204
 205         our_to_self_delay: u16,
 206         their_to_self_delay: Option<u16>,
 207
 208         old_secrets: [([u8; 32], u64); 49],
 209         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 210         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 211         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 212         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 213         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 214         /// can be used to derive the revocation key and claim the transactions.
 215         remote_commitment_txn_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 216         /// Cache used to make pruning of payment_preimages faster.
 217         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 218         /// remote transactions (ie should remain pretty small).
 219         /// Serialized to disk but should generally not be sent to Watchtowers.
 220         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 221
 222         // We store two local commitment transactions to avoid any race conditions where we may update
 223         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 224         // various monitors for one channel being out of sync, and us broadcasting a local
 225         // transaction for which we have deleted claim information on some watchtowers.
 226         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 227         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 228
 229         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 230
 231         destination_script: Script,
 232         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 233 }
 234 impl Clone for ChannelMonitor {
 235         fn clone(&self) -> Self {
 236                 ChannelMonitor {
 237                         funding_txo: self.funding_txo.clone(),
 238                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 239
 240                         key_storage: self.key_storage.clone(),
 241                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 242                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 243                         their_delayed_payment_base_key: self.their_delayed_payment_base_key.clone(),
 244                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 245
 246                         our_to_self_delay: self.our_to_self_delay,
 247                         their_to_self_delay: self.their_to_self_delay,
 248
 249                         old_secrets: self.old_secrets.clone(),
 250                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 251                         remote_commitment_txn_on_chain: Mutex::new((*self.remote_commitment_txn_on_chain.lock().unwrap()).clone()),
 252                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 253
 254                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 255                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 256
 257                         payment_preimages: self.payment_preimages.clone(),
 258
 259                         destination_script: self.destination_script.clone(),
 260                         secp_ctx: self.secp_ctx.clone(),
 261                 }
 262         }
 263 }
 264
 265 #[cfg(any(test, feature = "fuzztarget"))]
 266 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 267 /// underlying object
 268 impl PartialEq for ChannelMonitor {
 269         fn eq(&self, other: &Self) -> bool {
 270                 if self.funding_txo != other.funding_txo ||
 271                         self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 272                         self.key_storage != other.key_storage ||
 273                         self.delayed_payment_base_key != other.delayed_payment_base_key ||
 274                         self.their_htlc_base_key != other.their_htlc_base_key ||
 275                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 276                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 277                         self.our_to_self_delay != other.our_to_self_delay ||
 278                         self.their_to_self_delay != other.their_to_self_delay ||
 279                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 280                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 281                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 282                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 283                         self.payment_preimages != other.payment_preimages ||
 284                         self.destination_script != other.destination_script
 285                 {
 286                         false
 287                 } else {
 288                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 289                                 if secret != o_secret || idx != o_idx {
 290                                         return false
 291                                 }
 292                         }
 293                         let us = self.remote_commitment_txn_on_chain.lock().unwrap();
 294                         let them = other.remote_commitment_txn_on_chain.lock().unwrap();
 295                         *us == *them
 296                 }
 297         }
 298 }
 299
 300 impl ChannelMonitor {
 301         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 {
 302                 ChannelMonitor {
 303                         funding_txo: None,
 304                         commitment_transaction_number_obscure_factor: 0,
 305
 306                         key_storage: KeyStorage::PrivMode {
 307                                 revocation_base_key: revocation_base_key.clone(),
 308                                 htlc_base_key: htlc_base_key.clone(),
 309                         },
 310                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 311                         their_htlc_base_key: None,
 312                         their_delayed_payment_base_key: None,
 313                         their_cur_revocation_points: None,
 314
 315                         our_to_self_delay: our_to_self_delay,
 316                         their_to_self_delay: None,
 317
 318                         old_secrets: [([0; 32], 1 << 48); 49],
 319                         remote_claimable_outpoints: HashMap::new(),
 320                         remote_commitment_txn_on_chain: Mutex::new(HashMap::new()),
 321                         remote_hash_commitment_number: HashMap::new(),
 322
 323                         prev_local_signed_commitment_tx: None,
 324                         current_local_signed_commitment_tx: None,
 325
 326                         payment_preimages: HashMap::new(),
 327
 328                         destination_script: destination_script,
 329                         secp_ctx: Secp256k1::new(),
 330                 }
 331         }
 332
 333         #[inline]
 334         fn place_secret(idx: u64) -> u8 {
 335                 for i in 0..48 {
 336                         if idx & (1 << i) == (1 << i) {
 337                                 return i
 338                         }
 339                 }
 340                 48
 341         }
 342
 343         #[inline]
 344         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 345                 let mut res: [u8; 32] = secret;
 346                 for i in 0..bits {
 347                         let bitpos = bits - 1 - i;
 348                         if idx & (1 << bitpos) == (1 << bitpos) {
 349                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 350                                 let mut sha = Sha256::new();
 351                                 sha.input(&res);
 352                                 sha.result(&mut res);
 353                         }
 354                 }
 355                 res
 356         }
 357
 358         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 359         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 360         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 361         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 362         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 363         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 364                 let pos = ChannelMonitor::place_secret(idx);
 365                 for i in 0..pos {
 366                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 367                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 368                                 return Err(HandleError{err: "Previous secret did not match new one", action: None})
 369                         }
 370                 }
 371                 self.old_secrets[pos as usize] = (secret, idx);
 372
 373                 if let Some(new_revocation_point) = their_next_revocation_point {
 374                         match self.their_cur_revocation_points {
 375                                 Some(old_points) => {
 376                                         if old_points.0 == new_revocation_point.0 + 1 {
 377                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 378                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 379                                                 if let Some(old_second_point) = old_points.2 {
 380                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 381                                                 } else {
 382                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 383                                                 }
 384                                         } else {
 385                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 386                                         }
 387                                 },
 388                                 None => {
 389                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 390                                 }
 391                         }
 392                 }
 393
 394                 if !self.payment_preimages.is_empty() {
 395                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 396                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 397                         let min_idx = self.get_min_seen_secret();
 398                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 399
 400                         self.payment_preimages.retain(|&k, _| {
 401                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 402                                         if k == htlc.payment_hash {
 403                                                 return true
 404                                         }
 405                                 }
 406                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 407                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 408                                                 if k == htlc.payment_hash {
 409                                                         return true
 410                                                 }
 411                                         }
 412                                 }
 413                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 414                                         if *cn < min_idx {
 415                                                 return true
 416                                         }
 417                                         true
 418                                 } else { false };
 419                                 if contains {
 420                                         remote_hash_commitment_number.remove(&k);
 421                                 }
 422                                 false
 423                         });
 424                 }
 425
 426                 Ok(())
 427         }
 428
 429         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 430         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 431         /// possibly future revocation/preimage information) to claim outputs where possible.
 432         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 433         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 434                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 435                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 436                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 437                 // timeouts)
 438                 for htlc in &htlc_outputs {
 439                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 440                 }
 441                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 442         }
 443
 444         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 445         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 446         /// is important that any clones of this channel monitor (including remote clones) by kept
 447         /// up-to-date as our local commitment transaction is updated.
 448         /// Panics if set_their_to_self_delay has never been called.
 449         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)>) {
 450                 assert!(self.their_to_self_delay.is_some());
 451                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 452                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 453                         txid: signed_commitment_tx.txid(),
 454                         tx: signed_commitment_tx,
 455                         revocation_key: local_keys.revocation_key,
 456                         a_htlc_key: local_keys.a_htlc_key,
 457                         b_htlc_key: local_keys.b_htlc_key,
 458                         delayed_payment_key: local_keys.a_delayed_payment_key,
 459                         feerate_per_kw,
 460                         htlc_outputs,
 461                 });
 462         }
 463
 464         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 465         /// commitment_tx_infos which contain the payment hash have been revoked.
 466         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 467                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 468         }
 469
 470         /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
 471         /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
 472         /// chain for new blocks/transactions.
 473         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 474                 if self.funding_txo.is_some() {
 475                         // We should be able to compare the entire funding_txo, but in fuzztarget its trivially
 476                         // easy to collide the funding_txo hash and have a different scriptPubKey.
 477                         if other.funding_txo.is_some() && other.funding_txo.as_ref().unwrap().0 != self.funding_txo.as_ref().unwrap().0 {
 478                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", action: None});
 479                         }
 480                 } else {
 481                         self.funding_txo = other.funding_txo.take();
 482                 }
 483                 let other_min_secret = other.get_min_seen_secret();
 484                 let our_min_secret = self.get_min_seen_secret();
 485                 if our_min_secret > other_min_secret {
 486                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 487                 }
 488                 if our_min_secret >= other_min_secret {
 489                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 490                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 491                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 492                         }
 493                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 494                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 495                         }
 496                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 497                                 self.current_local_signed_commitment_tx = Some(local_tx);
 498                         }
 499                         self.payment_preimages = other.payment_preimages;
 500                 }
 501                 Ok(())
 502         }
 503
 504         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 505         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 506                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 507                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 508         }
 509
 510         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 511         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 512         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 513         /// provides slightly better privacy.
 514         /// It's the responsibility of the caller to register outpoint and script with passing the former
 515         /// value as key to add_update_monitor.
 516         pub(super) fn set_funding_info(&mut self, funding_info: (OutPoint, Script)) {
 517                 self.funding_txo = Some(funding_info);
 518         }
 519
 520         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
 521         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
 522                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 523                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
 524         }
 525
 526         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 527                 self.their_to_self_delay = Some(their_to_self_delay);
 528         }
 529
 530         pub(super) fn unset_funding_info(&mut self) {
 531                 self.funding_txo = None;
 532         }
 533
 534         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
 535         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 536                 match self.funding_txo {
 537                         Some((outpoint, _)) => Some(outpoint),
 538                         None => None
 539                 }
 540         }
 541
 542         /// Serializes into a vec, with various modes for the exposed pub fns
 543         fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
 544                 //TODO: We still write out all the serialization here manually instead of using the fancy
 545                 //serialization framework we have, we should migrate things over to it.
 546                 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
 547                 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
 548
 549                 match &self.funding_txo {
 550                         &Some((ref outpoint, ref script)) => {
 551                                 writer.write_all(&outpoint.txid[..])?;
 552                                 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
 553                                 writer.write_all(&byte_utils::be64_to_array(script.len() as u64))?;
 554                                 writer.write_all(&script[..])?;
 555                         },
 556                         &None => {
 557                                 // We haven't even been initialized...not sure why anyone is serializing us, but
 558                                 // not much to give them.
 559                                 return Ok(());
 560                         },
 561                 }
 562
 563                 // Set in initial Channel-object creation, so should always be set by now:
 564                 writer.write_all(&byte_utils::be48_to_array(self.commitment_transaction_number_obscure_factor))?;
 565
 566                 match self.key_storage {
 567                         KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 568                                 writer.write_all(&[0; 1])?;
 569                                 writer.write_all(&revocation_base_key[..])?;
 570                                 writer.write_all(&htlc_base_key[..])?;
 571                         },
 572                         KeyStorage::SigsMode { .. } => unimplemented!(),
 573                 }
 574
 575                 writer.write_all(&self.delayed_payment_base_key.serialize())?;
 576                 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
 577                 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
 578
 579                 match self.their_cur_revocation_points {
 580                         Some((idx, pubkey, second_option)) => {
 581                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
 582                                 writer.write_all(&pubkey.serialize())?;
 583                                 match second_option {
 584                                         Some(second_pubkey) => {
 585                                                 writer.write_all(&second_pubkey.serialize())?;
 586                                         },
 587                                         None => {
 588                                                 writer.write_all(&[0; 33])?;
 589                                         },
 590                                 }
 591                         },
 592                         None => {
 593                                 writer.write_all(&byte_utils::be48_to_array(0))?;
 594                         },
 595                 }
 596
 597                 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
 598                 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
 599
 600                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 601                         writer.write_all(secret)?;
 602                         writer.write_all(&byte_utils::be64_to_array(*idx))?;
 603                 }
 604
 605                 macro_rules! serialize_htlc_in_commitment {
 606                         ($htlc_output: expr) => {
 607                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
 608                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
 609                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
 610                                 writer.write_all(&$htlc_output.payment_hash)?;
 611                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.transaction_output_index))?;
 612                         }
 613                 }
 614
 615                 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
 616                 for (txid, htlc_outputs) in self.remote_claimable_outpoints.iter() {
 617                         writer.write_all(&txid[..])?;
 618                         writer.write_all(&byte_utils::be64_to_array(htlc_outputs.len() as u64))?;
 619                         for htlc_output in htlc_outputs.iter() {
 620                                 serialize_htlc_in_commitment!(htlc_output);
 621                         }
 622                 }
 623
 624                 {
 625                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
 626                         writer.write_all(&byte_utils::be64_to_array(remote_commitment_txn_on_chain.len() as u64))?;
 627                         for (txid, commitment_number) in remote_commitment_txn_on_chain.iter() {
 628                                 writer.write_all(&txid[..])?;
 629                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
 630                         }
 631                 }
 632
 633                 if for_local_storage {
 634                         writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
 635                         for (payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 636                                 writer.write_all(payment_hash)?;
 637                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
 638                         }
 639                 } else {
 640                         writer.write_all(&byte_utils::be64_to_array(0))?;
 641                 }
 642
 643                 macro_rules! serialize_local_tx {
 644                         ($local_tx: expr) => {
 645                                 let tx_ser = serialize::serialize(&$local_tx.tx).unwrap();
 646                                 writer.write_all(&byte_utils::be64_to_array(tx_ser.len() as u64))?;
 647                                 writer.write_all(&tx_ser)?;
 648
 649                                 writer.write_all(&$local_tx.revocation_key.serialize())?;
 650                                 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
 651                                 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
 652                                 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
 653
 654                                 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
 655                                 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
 656                                 for &(ref htlc_output, ref their_sig, ref our_sig) in $local_tx.htlc_outputs.iter() {
 657                                         serialize_htlc_in_commitment!(htlc_output);
 658                                         writer.write_all(&their_sig.serialize_compact(&self.secp_ctx))?;
 659                                         writer.write_all(&our_sig.serialize_compact(&self.secp_ctx))?;
 660                                 }
 661                         }
 662                 }
 663
 664                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 665                         writer.write_all(&[1; 1])?;
 666                         serialize_local_tx!(prev_local_tx);
 667                 } else {
 668                         writer.write_all(&[0; 1])?;
 669                 }
 670
 671                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 672                         writer.write_all(&[1; 1])?;
 673                         serialize_local_tx!(cur_local_tx);
 674                 } else {
 675                         writer.write_all(&[0; 1])?;
 676                 }
 677
 678                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
 679                 for payment_preimage in self.payment_preimages.values() {
 680                         writer.write_all(payment_preimage)?;
 681                 }
 682
 683                 writer.write_all(&byte_utils::be64_to_array(self.destination_script.len() as u64))?;
 684                 writer.write_all(&self.destination_script[..])?;
 685
 686                 Ok(())
 687         }
 688
 689         /// Writes this monitor into the given writer, suitable for writing to disk.
 690         pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 691                 self.write(writer, true)
 692         }
 693
 694         /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
 695         pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 696                 self.write(writer, false)
 697         }
 698
 699         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 700         //we want to leave out (eg funding_txo, etc).
 701
 702         /// Can only fail if idx is < get_min_seen_secret
 703         pub(super) fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 704                 for i in 0..self.old_secrets.len() {
 705                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 706                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 707                         }
 708                 }
 709                 assert!(idx < self.get_min_seen_secret());
 710                 Err(HandleError{err: "idx too low", action: None})
 711         }
 712
 713         pub(super) fn get_min_seen_secret(&self) -> u64 {
 714                 //TODO This can be optimized?
 715                 let mut min = 1 << 48;
 716                 for &(_, idx) in self.old_secrets.iter() {
 717                         if idx < min {
 718                                 min = idx;
 719                         }
 720                 }
 721                 min
 722         }
 723
 724         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 725         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 726         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 727         /// HTLC-Success/HTLC-Timeout transactions.
 728         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>)) {
 729                 // Most secp and related errors trying to create keys means we have no hope of constructing
 730                 // a spend transaction...so we return no transactions to broadcast
 731                 let mut txn_to_broadcast = Vec::new();
 732                 let mut watch_outputs = Vec::new();
 733
 734                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 735                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 736
 737                 macro_rules! ignore_error {
 738                         ( $thing : expr ) => {
 739                                 match $thing {
 740                                         Ok(a) => a,
 741                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs))
 742                                 }
 743                         };
 744                 }
 745
 746                 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);
 747                 if commitment_number >= self.get_min_seen_secret() {
 748                         let secret = self.get_secret(commitment_number).unwrap();
 749                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 750                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 751                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 752                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 753                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 754                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 755                                 },
 756                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 757                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
 758                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 759                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 760                                 },
 761                         };
 762                         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()));
 763                         let a_htlc_key = match self.their_htlc_base_key {
 764                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 765                                 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)),
 766                         };
 767
 768                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 769                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 770
 771                         let mut total_value = 0;
 772                         let mut values = Vec::new();
 773                         let mut inputs = Vec::new();
 774                         let mut htlc_idxs = Vec::new();
 775
 776                         for (idx, outp) in tx.output.iter().enumerate() {
 777                                 if outp.script_pubkey == revokeable_p2wsh {
 778                                         inputs.push(TxIn {
 779                                                 previous_output: BitcoinOutPoint {
 780                                                         txid: commitment_txid,
 781                                                         vout: idx as u32,
 782                                                 },
 783                                                 script_sig: Script::new(),
 784                                                 sequence: 0xfffffffd,
 785                                                 witness: Vec::new(),
 786                                         });
 787                                         htlc_idxs.push(None);
 788                                         values.push(outp.value);
 789                                         total_value += outp.value;
 790                                         break; // There can only be one of these
 791                                 }
 792                         }
 793
 794                         macro_rules! sign_input {
 795                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 796                                         {
 797                                                 let (sig, redeemscript) = match self.key_storage {
 798                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
 799                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
 800                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
 801                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
 802                                                                 };
 803                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 804                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
 805                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
 806                                                         },
 807                                                         KeyStorage::SigsMode { .. } => {
 808                                                                 unimplemented!();
 809                                                         }
 810                                                 };
 811                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 812                                                 $input.witness[0].push(SigHashType::All as u8);
 813                                                 if $htlc_idx.is_none() {
 814                                                         $input.witness.push(vec!(1));
 815                                                 } else {
 816                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
 817                                                 }
 818                                                 $input.witness.push(redeemscript.into_bytes());
 819                                         }
 820                                 }
 821                         }
 822
 823                         if let Some(per_commitment_data) = per_commitment_option {
 824                                 inputs.reserve_exact(per_commitment_data.len());
 825
 826                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
 827                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 828                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
 829                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
 830                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
 831                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
 832                                         }
 833                                         let input = TxIn {
 834                                                 previous_output: BitcoinOutPoint {
 835                                                         txid: commitment_txid,
 836                                                         vout: htlc.transaction_output_index,
 837                                                 },
 838                                                 script_sig: Script::new(),
 839                                                 sequence: 0xfffffffd,
 840                                                 witness: Vec::new(),
 841                                         };
 842                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 843                                                 inputs.push(input);
 844                                                 htlc_idxs.push(Some(idx));
 845                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
 846                                                 total_value += htlc.amount_msat / 1000;
 847                                         } else {
 848                                                 let mut single_htlc_tx = Transaction {
 849                                                         version: 2,
 850                                                         lock_time: 0,
 851                                                         input: vec![input],
 852                                                         output: vec!(TxOut {
 853                                                                 script_pubkey: self.destination_script.clone(),
 854                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 855                                                         }),
 856                                                 };
 857                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
 858                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
 859                                                 txn_to_broadcast.push(single_htlc_tx);
 860                                         }
 861                                 }
 862                         }
 863
 864                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() { // ie we're confident this is actually ours
 865                                 // We're definitely a remote commitment transaction!
 866                                 watch_outputs.append(&mut tx.output.clone());
 867                                 self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
 868                         }
 869                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
 870
 871                         let outputs = vec!(TxOut {
 872                                 script_pubkey: self.destination_script.clone(),
 873                                 value: total_value, //TODO: - fee
 874                         });
 875                         let mut spend_tx = Transaction {
 876                                 version: 2,
 877                                 lock_time: 0,
 878                                 input: inputs,
 879                                 output: outputs,
 880                         };
 881
 882                         let mut values_drain = values.drain(..);
 883                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 884
 885                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
 886                                 let value = values_drain.next().unwrap();
 887                                 sign_input!(sighash_parts, input, htlc_idx, value);
 888                         }
 889
 890                         txn_to_broadcast.push(spend_tx);
 891                 } else if let Some(per_commitment_data) = per_commitment_option {
 892                         // While this isn't useful yet, there is a potential race where if a counterparty
 893                         // revokes a state at the same time as the commitment transaction for that state is
 894                         // confirmed, and the watchtower receives the block before the user, the user could
 895                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
 896                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
 897                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
 898                         // insert it here.
 899                         watch_outputs.append(&mut tx.output.clone());
 900                         self.remote_commitment_txn_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
 901
 902                         if let Some(revocation_points) = self.their_cur_revocation_points {
 903                                 let revocation_point_option =
 904                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
 905                                         else if let Some(point) = revocation_points.2.as_ref() {
 906                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
 907                                         } else { None };
 908                                 if let Some(revocation_point) = revocation_point_option {
 909                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 910                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 911                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
 912                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
 913                                                 },
 914                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 915                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
 916                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
 917                                                 },
 918                                         };
 919                                         let a_htlc_key = match self.their_htlc_base_key {
 920                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs)),
 921                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
 922                                         };
 923
 924                                         let mut total_value = 0;
 925                                         let mut values = Vec::new();
 926                                         let mut inputs = Vec::new();
 927
 928                                         macro_rules! sign_input {
 929                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
 930                                                         {
 931                                                                 let (sig, redeemscript) = match self.key_storage {
 932                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
 933                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
 934                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 935                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 936                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
 937                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
 938                                                                         },
 939                                                                         KeyStorage::SigsMode { .. } => {
 940                                                                                 unimplemented!();
 941                                                                         }
 942                                                                 };
 943                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 944                                                                 $input.witness[0].push(SigHashType::All as u8);
 945                                                                 $input.witness.push($preimage);
 946                                                                 $input.witness.push(redeemscript.into_bytes());
 947                                                         }
 948                                                 }
 949                                         }
 950
 951                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
 952                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
 953                                                         let input = TxIn {
 954                                                                 previous_output: BitcoinOutPoint {
 955                                                                         txid: commitment_txid,
 956                                                                         vout: htlc.transaction_output_index,
 957                                                                 },
 958                                                                 script_sig: Script::new(),
 959                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
 960                                                                 witness: Vec::new(),
 961                                                         };
 962                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 963                                                                 inputs.push(input);
 964                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
 965                                                                 total_value += htlc.amount_msat / 1000;
 966                                                         } else {
 967                                                                 let mut single_htlc_tx = Transaction {
 968                                                                         version: 2,
 969                                                                         lock_time: 0,
 970                                                                         input: vec![input],
 971                                                                         output: vec!(TxOut {
 972                                                                                 script_pubkey: self.destination_script.clone(),
 973                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 974                                                                         }),
 975                                                                 };
 976                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
 977                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
 978                                                                 txn_to_broadcast.push(single_htlc_tx);
 979                                                         }
 980                                                 }
 981                                         }
 982
 983                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs)); } // Nothing to be done...probably a false positive/local tx
 984
 985                                         let outputs = vec!(TxOut {
 986                                                 script_pubkey: self.destination_script.clone(),
 987                                                 value: total_value, //TODO: - fee
 988                                         });
 989                                         let mut spend_tx = Transaction {
 990                                                 version: 2,
 991                                                 lock_time: 0,
 992                                                 input: inputs,
 993                                                 output: outputs,
 994                                         };
 995
 996                                         let mut values_drain = values.drain(..);
 997                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 998
 999                                         for input in spend_tx.input.iter_mut() {
1000                                                 let value = values_drain.next().unwrap();
1001                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
1002                                         }
1003
1004                                         txn_to_broadcast.push(spend_tx);
1005                                 }
1006                         }
1007                 }
1008
1009                 (txn_to_broadcast, (commitment_txid, watch_outputs))
1010         }
1011
1012         /// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
1013         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
1014                 if tx.input.len() != 1 || tx.output.len() != 1 {
1015                         return None;
1016                 }
1017
1018                 macro_rules! ignore_error {
1019                         ( $thing : expr ) => {
1020                                 match $thing {
1021                                         Ok(a) => a,
1022                                         Err(_) => return None
1023                                 }
1024                         };
1025                 }
1026
1027                 let secret = ignore_error!(self.get_secret(commitment_number));
1028                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
1029                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1030                 let revocation_pubkey = match self.key_storage {
1031                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1032                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1033                         },
1034                         KeyStorage::SigsMode { ref revocation_base_key, .. } => {
1035                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
1036                         },
1037                 };
1038                 let delayed_key = match self.their_delayed_payment_base_key {
1039                         None => return None,
1040                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1041                 };
1042                 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
1043                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1044                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1045
1046                 let mut inputs = Vec::new();
1047                 let mut amount = 0;
1048
1049                 if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
1050                         inputs.push(TxIn {
1051                                 previous_output: BitcoinOutPoint {
1052                                         txid: htlc_txid,
1053                                         vout: 0,
1054                                 },
1055                                 script_sig: Script::new(),
1056                                 sequence: 0xfffffffd,
1057                                 witness: Vec::new(),
1058                         });
1059                         amount = tx.output[0].value;
1060                 }
1061
1062                 if !inputs.is_empty() {
1063                         let outputs = vec!(TxOut {
1064                                 script_pubkey: self.destination_script.clone(),
1065                                 value: amount, //TODO: - fee
1066                         });
1067
1068                         let mut spend_tx = Transaction {
1069                                 version: 2,
1070                                 lock_time: 0,
1071                                 input: inputs,
1072                                 output: outputs,
1073                         };
1074
1075                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1076
1077                         let sig = match self.key_storage {
1078                                 KeyStorage::PrivMode { ref revocation_base_key, .. } => {
1079                                         let sighash = ignore_error!(Message::from_slice(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]));
1080                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1081                                         self.secp_ctx.sign(&sighash, &revocation_key)
1082                                 }
1083                                 KeyStorage::SigsMode { .. } => {
1084                                         unimplemented!();
1085                                 }
1086                         };
1087                         spend_tx.input[0].witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
1088                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1089                         spend_tx.input[0].witness.push(vec!(1));
1090                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1091
1092                         Some(spend_tx)
1093                 } else { None }
1094         }
1095
1096         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
1097                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1098
1099                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
1100                         if htlc.offered {
1101                                 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);
1102
1103                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1104
1105                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1106                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1107                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1108                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1109
1110                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1111                                 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());
1112
1113                                 res.push(htlc_timeout_tx);
1114                         } else {
1115                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1116                                         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);
1117
1118                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1119
1120                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
1121                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1122                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
1123                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1124
1125                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
1126                                         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());
1127
1128                                         res.push(htlc_success_tx);
1129                                 }
1130                         }
1131                 }
1132
1133                 res
1134         }
1135
1136         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1137         /// revoked using data in local_claimable_outpoints.
1138         /// Should not be used if check_spend_revoked_transaction succeeds.
1139         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
1140                 let commitment_txid = tx.txid();
1141                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1142                         if local_tx.txid == commitment_txid {
1143                                 return self.broadcast_by_local_state(local_tx);
1144                         }
1145                 }
1146                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1147                         if local_tx.txid == commitment_txid {
1148                                 return self.broadcast_by_local_state(local_tx);
1149                         }
1150                 }
1151                 Vec::new()
1152         }
1153
1154         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface)-> Vec<(Sha256dHash, Vec<TxOut>)> {
1155                 let mut watch_outputs = Vec::new();
1156                 for tx in txn_matched {
1157                         if tx.input.len() == 1 {
1158                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1159                                 // commitment transactions and HTLC transactions will all only ever have one input,
1160                                 // which is an easy way to filter out any potential non-matching txn for lazy
1161                                 // filters.
1162                                 let prevout = &tx.input[0].previous_output;
1163                                 let mut txn: Vec<Transaction> = Vec::new();
1164                                 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) {
1165                                         let (remote_txn, new_outputs) = self.check_spend_remote_transaction(tx, height);
1166                                         txn = remote_txn;
1167                                         if !new_outputs.1.is_empty() {
1168                                                 watch_outputs.push(new_outputs);
1169                                         }
1170                                         if txn.is_empty() {
1171                                                 txn = self.check_spend_local_transaction(tx, height);
1172                                         }
1173                                 } else {
1174                                         let remote_commitment_txn_on_chain = self.remote_commitment_txn_on_chain.lock().unwrap();
1175                                         if let Some(commitment_number) = remote_commitment_txn_on_chain.get(&prevout.txid) {
1176                                                 if let Some(tx) = self.check_spend_remote_htlc(tx, *commitment_number) {
1177                                                         txn.push(tx);
1178                                                 }
1179                                         }
1180                                 }
1181                                 for tx in txn.iter() {
1182                                         broadcaster.broadcast_transaction(tx);
1183                                 }
1184                         }
1185                 }
1186                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1187                         let mut needs_broadcast = false;
1188                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1189                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1190                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1191                                                 needs_broadcast = true;
1192                                         }
1193                                 }
1194                         }
1195
1196                         if needs_broadcast {
1197                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1198                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
1199                                         broadcaster.broadcast_transaction(&tx);
1200                                 }
1201                         }
1202                 }
1203                 watch_outputs
1204         }
1205
1206         pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
1207                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1208                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
1209                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
1210                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
1211                                                 return true;
1212                                         }
1213                                 }
1214                         }
1215                 }
1216                 false
1217         }
1218 }
1219
1220 impl<R: ::std::io::Read> Readable<R> for ChannelMonitor {
1221         fn read(reader: &mut R) -> Result<Self, DecodeError> {
1222                 // TODO: read_to_end and then deserializing from that vector is really dumb, we should
1223                 // actually use the fancy serialization framework we have instead of hacking around it.
1224                 let mut datavec = Vec::new();
1225                 reader.read_to_end(&mut datavec)?;
1226                 let data = &datavec;
1227
1228                 let mut read_pos = 0;
1229                 macro_rules! read_bytes {
1230                         ($byte_count: expr) => {
1231                                 {
1232                                         if ($byte_count as usize) > data.len() - read_pos {
1233                                                 return Err(DecodeError::ShortRead);
1234                                         }
1235                                         read_pos += $byte_count as usize;
1236                                         &data[read_pos - $byte_count as usize..read_pos]
1237                                 }
1238                         }
1239                 }
1240
1241                 let secp_ctx = Secp256k1::new();
1242                 macro_rules! unwrap_obj {
1243                         ($key: expr) => {
1244                                 match $key {
1245                                         Ok(res) => res,
1246                                         Err(_) => return Err(DecodeError::InvalidValue),
1247                                 }
1248                         }
1249                 }
1250
1251                 let _ver = read_bytes!(1)[0];
1252                 let min_ver = read_bytes!(1)[0];
1253                 if min_ver > SERIALIZATION_VERSION {
1254                         return Err(DecodeError::UnknownVersion);
1255                 }
1256
1257                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
1258                 // barely-init'd ChannelMonitors that we can't do anything with.
1259                 let outpoint = OutPoint {
1260                         txid: Sha256dHash::from(read_bytes!(32)),
1261                         index: byte_utils::slice_to_be16(read_bytes!(2)),
1262                 };
1263                 let script_len = byte_utils::slice_to_be64(read_bytes!(8));
1264                 let funding_txo = Some((outpoint, Script::from(read_bytes!(script_len).to_vec())));
1265                 let commitment_transaction_number_obscure_factor = byte_utils::slice_to_be48(read_bytes!(6));
1266
1267                 let key_storage = match read_bytes!(1)[0] {
1268                         0 => {
1269                                 KeyStorage::PrivMode {
1270                                         revocation_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
1271                                         htlc_base_key: unwrap_obj!(SecretKey::from_slice(&secp_ctx, read_bytes!(32))),
1272                                 }
1273                         },
1274                         _ => return Err(DecodeError::InvalidValue),
1275                 };
1276
1277                 let delayed_payment_base_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1278                 let their_htlc_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
1279                 let their_delayed_payment_base_key = Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33))));
1280
1281                 let their_cur_revocation_points = {
1282                         let first_idx = byte_utils::slice_to_be48(read_bytes!(6));
1283                         if first_idx == 0 {
1284                                 None
1285                         } else {
1286                                 let first_point = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1287                                 let second_point_slice = read_bytes!(33);
1288                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
1289                                         Some((first_idx, first_point, None))
1290                                 } else {
1291                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&secp_ctx, second_point_slice)))))
1292                                 }
1293                         }
1294                 };
1295
1296                 let our_to_self_delay = byte_utils::slice_to_be16(read_bytes!(2));
1297                 let their_to_self_delay = Some(byte_utils::slice_to_be16(read_bytes!(2)));
1298
1299                 let mut old_secrets = [([0; 32], 1 << 48); 49];
1300                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
1301                         secret.copy_from_slice(read_bytes!(32));
1302                         *idx = byte_utils::slice_to_be64(read_bytes!(8));
1303                 }
1304
1305                 macro_rules! read_htlc_in_commitment {
1306                         () => {
1307                                 {
1308                                         let offered = match read_bytes!(1)[0] {
1309                                                 0 => false, 1 => true,
1310                                                 _ => return Err(DecodeError::InvalidValue),
1311                                         };
1312                                         let amount_msat = byte_utils::slice_to_be64(read_bytes!(8));
1313                                         let cltv_expiry = byte_utils::slice_to_be32(read_bytes!(4));
1314                                         let mut payment_hash = [0; 32];
1315                                         payment_hash[..].copy_from_slice(read_bytes!(32));
1316                                         let transaction_output_index = byte_utils::slice_to_be32(read_bytes!(4));
1317
1318                                         HTLCOutputInCommitment {
1319                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
1320                                         }
1321                                 }
1322                         }
1323                 }
1324
1325                 let remote_claimable_outpoints_len = byte_utils::slice_to_be64(read_bytes!(8));
1326                 if remote_claimable_outpoints_len > data.len() as u64 / 64 { return Err(DecodeError::BadLengthDescriptor); }
1327                 let mut remote_claimable_outpoints = HashMap::with_capacity(remote_claimable_outpoints_len as usize);
1328                 for _ in 0..remote_claimable_outpoints_len {
1329                         let txid = Sha256dHash::from(read_bytes!(32));
1330                         let outputs_count = byte_utils::slice_to_be64(read_bytes!(8));
1331                         if outputs_count > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1332                         let mut outputs = Vec::with_capacity(outputs_count as usize);
1333                         for _ in 0..outputs_count {
1334                                 outputs.push(read_htlc_in_commitment!());
1335                         }
1336                         if let Some(_) = remote_claimable_outpoints.insert(txid, outputs) {
1337                                 return Err(DecodeError::InvalidValue);
1338                         }
1339                 }
1340
1341                 let remote_commitment_txn_on_chain_len = byte_utils::slice_to_be64(read_bytes!(8));
1342                 if remote_commitment_txn_on_chain_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1343                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(remote_commitment_txn_on_chain_len as usize);
1344                 for _ in 0..remote_commitment_txn_on_chain_len {
1345                         let txid = Sha256dHash::from(read_bytes!(32));
1346                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
1347                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, commitment_number) {
1348                                 return Err(DecodeError::InvalidValue);
1349                         }
1350                 }
1351
1352                 let remote_hash_commitment_number_len = byte_utils::slice_to_be64(read_bytes!(8));
1353                 if remote_hash_commitment_number_len > data.len() as u64 / 32 { return Err(DecodeError::BadLengthDescriptor); }
1354                 let mut remote_hash_commitment_number = HashMap::with_capacity(remote_hash_commitment_number_len as usize);
1355                 for _ in 0..remote_hash_commitment_number_len {
1356                         let mut txid = [0; 32];
1357                         txid[..].copy_from_slice(read_bytes!(32));
1358                         let commitment_number = byte_utils::slice_to_be48(read_bytes!(6));
1359                         if let Some(_) = remote_hash_commitment_number.insert(txid, commitment_number) {
1360                                 return Err(DecodeError::InvalidValue);
1361                         }
1362                 }
1363
1364                 macro_rules! read_local_tx {
1365                         () => {
1366                                 {
1367                                         let tx_len = byte_utils::slice_to_be64(read_bytes!(8));
1368                                         let tx_ser = read_bytes!(tx_len);
1369                                         let tx: Transaction = unwrap_obj!(serialize::deserialize(tx_ser));
1370                                         if serialize::serialize(&tx).unwrap() != tx_ser {
1371                                                 // We check that the tx re-serializes to the same form to ensure there is
1372                                                 // no extra data, and as rust-bitcoin doesn't handle the 0-input ambiguity
1373                                                 // all that well.
1374                                                 return Err(DecodeError::InvalidValue);
1375                                         }
1376
1377                                         let revocation_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1378                                         let a_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1379                                         let b_htlc_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1380                                         let delayed_payment_key = unwrap_obj!(PublicKey::from_slice(&secp_ctx, read_bytes!(33)));
1381                                         let feerate_per_kw = byte_utils::slice_to_be64(read_bytes!(8));
1382
1383                                         let htlc_outputs_len = byte_utils::slice_to_be64(read_bytes!(8));
1384                                         if htlc_outputs_len > data.len() as u64 / 128 { return Err(DecodeError::BadLengthDescriptor); }
1385                                         let mut htlc_outputs = Vec::with_capacity(htlc_outputs_len as usize);
1386                                         for _ in 0..htlc_outputs_len {
1387                                                 htlc_outputs.push((read_htlc_in_commitment!(),
1388                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64))),
1389                                                                 unwrap_obj!(Signature::from_compact(&secp_ctx, read_bytes!(64)))));
1390                                         }
1391
1392                                         LocalSignedTx {
1393                                                 txid: tx.txid(),
1394                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw, htlc_outputs
1395                                         }
1396                                 }
1397                         }
1398                 }
1399
1400                 let prev_local_signed_commitment_tx = match read_bytes!(1)[0] {
1401                         0 => None,
1402                         1 => {
1403                                 Some(read_local_tx!())
1404                         },
1405                         _ => return Err(DecodeError::InvalidValue),
1406                 };
1407
1408                 let current_local_signed_commitment_tx = match read_bytes!(1)[0] {
1409                         0 => None,
1410                         1 => {
1411                                 Some(read_local_tx!())
1412                         },
1413                         _ => return Err(DecodeError::InvalidValue),
1414                 };
1415
1416                 let payment_preimages_len = byte_utils::slice_to_be64(read_bytes!(8));
1417                 if payment_preimages_len > data.len() as u64 / 32 { return Err(DecodeError::InvalidValue); }
1418                 let mut payment_preimages = HashMap::with_capacity(payment_preimages_len as usize);
1419                 let mut sha = Sha256::new();
1420                 for _ in 0..payment_preimages_len {
1421                         let mut preimage = [0; 32];
1422                         preimage[..].copy_from_slice(read_bytes!(32));
1423                         sha.reset();
1424                         sha.input(&preimage);
1425                         let mut hash = [0; 32];
1426                         sha.result(&mut hash);
1427                         if let Some(_) = payment_preimages.insert(hash, preimage) {
1428                                 return Err(DecodeError::InvalidValue);
1429                         }
1430                 }
1431
1432                 let destination_script_len = byte_utils::slice_to_be64(read_bytes!(8));
1433                 let destination_script = Script::from(read_bytes!(destination_script_len).to_vec());
1434
1435                 Ok(ChannelMonitor {
1436                         funding_txo,
1437                         commitment_transaction_number_obscure_factor,
1438
1439                         key_storage,
1440                         delayed_payment_base_key,
1441                         their_htlc_base_key,
1442                         their_delayed_payment_base_key,
1443                         their_cur_revocation_points,
1444
1445                         our_to_self_delay,
1446                         their_to_self_delay,
1447
1448                         old_secrets,
1449                         remote_claimable_outpoints,
1450                         remote_commitment_txn_on_chain: Mutex::new(remote_commitment_txn_on_chain),
1451                         remote_hash_commitment_number,
1452
1453                         prev_local_signed_commitment_tx,
1454                         current_local_signed_commitment_tx,
1455
1456                         payment_preimages,
1457
1458                         destination_script,
1459                         secp_ctx,
1460                 })
1461         }
1462
1463 }
1464
1465 #[cfg(test)]
1466 mod tests {
1467         use bitcoin::blockdata::script::Script;
1468         use bitcoin::blockdata::transaction::Transaction;
1469         use crypto::digest::Digest;
1470         use hex;
1471         use ln::channelmonitor::ChannelMonitor;
1472         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
1473         use util::sha2::Sha256;
1474         use secp256k1::key::{SecretKey,PublicKey};
1475         use secp256k1::{Secp256k1, Signature};
1476         use rand::{thread_rng,Rng};
1477
1478         #[test]
1479         fn test_per_commitment_storage() {
1480                 // Test vectors from BOLT 3:
1481                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1482                 let mut monitor: ChannelMonitor;
1483                 let secp_ctx = Secp256k1::new();
1484
1485                 macro_rules! test_secrets {
1486                         () => {
1487                                 let mut idx = 281474976710655;
1488                                 for secret in secrets.iter() {
1489                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1490                                         idx -= 1;
1491                                 }
1492                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1493                                 assert!(monitor.get_secret(idx).is_err());
1494                         };
1495                 }
1496
1497                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1498
1499                 {
1500                         // insert_secret correct sequence
1501                         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());
1502                         secrets.clear();
1503
1504                         secrets.push([0; 32]);
1505                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1506                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1507                         test_secrets!();
1508
1509                         secrets.push([0; 32]);
1510                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1511                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1512                         test_secrets!();
1513
1514                         secrets.push([0; 32]);
1515                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1516                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1517                         test_secrets!();
1518
1519                         secrets.push([0; 32]);
1520                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1521                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1522                         test_secrets!();
1523
1524                         secrets.push([0; 32]);
1525                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1526                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1527                         test_secrets!();
1528
1529                         secrets.push([0; 32]);
1530                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1531                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1532                         test_secrets!();
1533
1534                         secrets.push([0; 32]);
1535                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1536                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1537                         test_secrets!();
1538
1539                         secrets.push([0; 32]);
1540                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1541                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
1542                         test_secrets!();
1543                 }
1544
1545                 {
1546                         // insert_secret #1 incorrect
1547                         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());
1548                         secrets.clear();
1549
1550                         secrets.push([0; 32]);
1551                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1552                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1553                         test_secrets!();
1554
1555                         secrets.push([0; 32]);
1556                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1557                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
1558                                         "Previous secret did not match new one");
1559                 }
1560
1561                 {
1562                         // insert_secret #2 incorrect (#1 derived from incorrect)
1563                         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());
1564                         secrets.clear();
1565
1566                         secrets.push([0; 32]);
1567                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1568                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1569                         test_secrets!();
1570
1571                         secrets.push([0; 32]);
1572                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1573                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1574                         test_secrets!();
1575
1576                         secrets.push([0; 32]);
1577                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1578                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1579                         test_secrets!();
1580
1581                         secrets.push([0; 32]);
1582                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1583                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1584                                         "Previous secret did not match new one");
1585                 }
1586
1587                 {
1588                         // insert_secret #3 incorrect
1589                         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());
1590                         secrets.clear();
1591
1592                         secrets.push([0; 32]);
1593                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1594                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1595                         test_secrets!();
1596
1597                         secrets.push([0; 32]);
1598                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1599                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1600                         test_secrets!();
1601
1602                         secrets.push([0; 32]);
1603                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1604                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1605                         test_secrets!();
1606
1607                         secrets.push([0; 32]);
1608                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1609                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
1610                                         "Previous secret did not match new one");
1611                 }
1612
1613                 {
1614                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1615                         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());
1616                         secrets.clear();
1617
1618                         secrets.push([0; 32]);
1619                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1620                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1621                         test_secrets!();
1622
1623                         secrets.push([0; 32]);
1624                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1625                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1626                         test_secrets!();
1627
1628                         secrets.push([0; 32]);
1629                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1630                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1631                         test_secrets!();
1632
1633                         secrets.push([0; 32]);
1634                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1635                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1636                         test_secrets!();
1637
1638                         secrets.push([0; 32]);
1639                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1640                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1641                         test_secrets!();
1642
1643                         secrets.push([0; 32]);
1644                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1645                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1646                         test_secrets!();
1647
1648                         secrets.push([0; 32]);
1649                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1650                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1651                         test_secrets!();
1652
1653                         secrets.push([0; 32]);
1654                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1655                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1656                                         "Previous secret did not match new one");
1657                 }
1658
1659                 {
1660                         // insert_secret #5 incorrect
1661                         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());
1662                         secrets.clear();
1663
1664                         secrets.push([0; 32]);
1665                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1666                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1667                         test_secrets!();
1668
1669                         secrets.push([0; 32]);
1670                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1671                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1672                         test_secrets!();
1673
1674                         secrets.push([0; 32]);
1675                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1676                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1677                         test_secrets!();
1678
1679                         secrets.push([0; 32]);
1680                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1681                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1682                         test_secrets!();
1683
1684                         secrets.push([0; 32]);
1685                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1686                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1687                         test_secrets!();
1688
1689                         secrets.push([0; 32]);
1690                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1691                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1692                                         "Previous secret did not match new one");
1693                 }
1694
1695                 {
1696                         // insert_secret #6 incorrect (5 derived from incorrect)
1697                         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());
1698                         secrets.clear();
1699
1700                         secrets.push([0; 32]);
1701                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1702                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1703                         test_secrets!();
1704
1705                         secrets.push([0; 32]);
1706                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1707                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1708                         test_secrets!();
1709
1710                         secrets.push([0; 32]);
1711                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1712                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1713                         test_secrets!();
1714
1715                         secrets.push([0; 32]);
1716                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1717                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1718                         test_secrets!();
1719
1720                         secrets.push([0; 32]);
1721                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1722                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1723                         test_secrets!();
1724
1725                         secrets.push([0; 32]);
1726                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1727                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1728                         test_secrets!();
1729
1730                         secrets.push([0; 32]);
1731                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1732                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1733                         test_secrets!();
1734
1735                         secrets.push([0; 32]);
1736                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1737                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1738                                         "Previous secret did not match new one");
1739                 }
1740
1741                 {
1742                         // insert_secret #7 incorrect
1743                         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());
1744                         secrets.clear();
1745
1746                         secrets.push([0; 32]);
1747                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1748                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1749                         test_secrets!();
1750
1751                         secrets.push([0; 32]);
1752                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1753                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1754                         test_secrets!();
1755
1756                         secrets.push([0; 32]);
1757                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1758                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1759                         test_secrets!();
1760
1761                         secrets.push([0; 32]);
1762                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1763                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1764                         test_secrets!();
1765
1766                         secrets.push([0; 32]);
1767                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1768                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1769                         test_secrets!();
1770
1771                         secrets.push([0; 32]);
1772                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1773                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1774                         test_secrets!();
1775
1776                         secrets.push([0; 32]);
1777                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1778                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1779                         test_secrets!();
1780
1781                         secrets.push([0; 32]);
1782                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1783                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1784                                         "Previous secret did not match new one");
1785                 }
1786
1787                 {
1788                         // insert_secret #8 incorrect
1789                         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());
1790                         secrets.clear();
1791
1792                         secrets.push([0; 32]);
1793                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1794                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1795                         test_secrets!();
1796
1797                         secrets.push([0; 32]);
1798                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1799                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1800                         test_secrets!();
1801
1802                         secrets.push([0; 32]);
1803                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1804                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1805                         test_secrets!();
1806
1807                         secrets.push([0; 32]);
1808                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1809                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1810                         test_secrets!();
1811
1812                         secrets.push([0; 32]);
1813                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1814                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1815                         test_secrets!();
1816
1817                         secrets.push([0; 32]);
1818                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1819                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1820                         test_secrets!();
1821
1822                         secrets.push([0; 32]);
1823                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1824                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1825                         test_secrets!();
1826
1827                         secrets.push([0; 32]);
1828                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1829                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1830                                         "Previous secret did not match new one");
1831                 }
1832         }
1833
1834         #[test]
1835         fn test_prune_preimages() {
1836                 let secp_ctx = Secp256k1::new();
1837                 let dummy_sig = Signature::from_der(&secp_ctx, &hex::decode("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..]).unwrap();
1838
1839                 macro_rules! dummy_keys {
1840                         () => {
1841                                 {
1842                                         let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1843                                         TxCreationKeys {
1844                                                 per_commitment_point: dummy_key.clone(),
1845                                                 revocation_key: dummy_key.clone(),
1846                                                 a_htlc_key: dummy_key.clone(),
1847                                                 b_htlc_key: dummy_key.clone(),
1848                                                 a_delayed_payment_key: dummy_key.clone(),
1849                                                 b_payment_key: dummy_key.clone(),
1850                                         }
1851                                 }
1852                         }
1853                 }
1854                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
1855
1856                 let mut preimages = Vec::new();
1857                 {
1858                         let mut rng  = thread_rng();
1859                         for _ in 0..20 {
1860                                 let mut preimage = [0; 32];
1861                                 rng.fill_bytes(&mut preimage);
1862                                 let mut sha = Sha256::new();
1863                                 sha.input(&preimage);
1864                                 let mut hash = [0; 32];
1865                                 sha.result(&mut hash);
1866                                 preimages.push((preimage, hash));
1867                         }
1868                 }
1869
1870                 macro_rules! preimages_slice_to_htlc_outputs {
1871                         ($preimages_slice: expr) => {
1872                                 {
1873                                         let mut res = Vec::new();
1874                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
1875                                                 res.push(HTLCOutputInCommitment {
1876                                                         offered: true,
1877                                                         amount_msat: 0,
1878                                                         cltv_expiry: 0,
1879                                                         payment_hash: preimage.1.clone(),
1880                                                         transaction_output_index: idx as u32,
1881                                                 });
1882                                         }
1883                                         res
1884                                 }
1885                         }
1886                 }
1887                 macro_rules! preimages_to_local_htlcs {
1888                         ($preimages_slice: expr) => {
1889                                 {
1890                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
1891                                         let res: Vec<_> = inp.drain(..).map(|e| { (e, dummy_sig.clone(), dummy_sig.clone()) }).collect();
1892                                         res
1893                                 }
1894                         }
1895                 }
1896
1897                 macro_rules! test_preimages_exist {
1898                         ($preimages_slice: expr, $monitor: expr) => {
1899                                 for preimage in $preimages_slice {
1900                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
1901                                 }
1902                         }
1903                 }
1904
1905                 // Prune with one old state and a local commitment tx holding a few overlaps with the
1906                 // old state.
1907                 let delayed_payment_base_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap());
1908                 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());
1909                 monitor.set_their_to_self_delay(10);
1910
1911                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
1912                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655);
1913                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654);
1914                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653);
1915                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652);
1916                 for &(ref preimage, ref hash) in preimages.iter() {
1917                         monitor.provide_payment_preimage(hash, preimage);
1918                 }
1919
1920                 // Now provide a secret, pruning preimages 10-15
1921                 let mut secret = [0; 32];
1922                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1923                 monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1924                 assert_eq!(monitor.payment_preimages.len(), 15);
1925                 test_preimages_exist!(&preimages[0..10], monitor);
1926                 test_preimages_exist!(&preimages[15..20], monitor);
1927
1928                 // Now provide a further secret, pruning preimages 15-17
1929                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1930                 monitor.provide_secret(281474976710654, secret.clone(), None).unwrap();
1931                 assert_eq!(monitor.payment_preimages.len(), 13);
1932                 test_preimages_exist!(&preimages[0..10], monitor);
1933                 test_preimages_exist!(&preimages[17..20], monitor);
1934
1935                 // Now update local commitment tx info, pruning only element 18 as we still care about the
1936                 // previous commitment tx's preimages too
1937                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
1938                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1939                 monitor.provide_secret(281474976710653, secret.clone(), None).unwrap();
1940                 assert_eq!(monitor.payment_preimages.len(), 12);
1941                 test_preimages_exist!(&preimages[0..10], monitor);
1942                 test_preimages_exist!(&preimages[18..20], monitor);
1943
1944                 // But if we do it again, we'll prune 5-10
1945                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
1946                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1947                 monitor.provide_secret(281474976710652, secret.clone(), None).unwrap();
1948                 assert_eq!(monitor.payment_preimages.len(), 5);
1949                 test_preimages_exist!(&preimages[0..5], monitor);
1950         }
1951
1952         // Further testing is done in the ChannelManager integration tests.
1953 }