_ 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 latest ChannelMonitor must always be actively monitoring for chain updates (and no out-of-date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, Builder};
  18 use bitcoin::blockdata::opcodes;
  19 use bitcoin::consensus::encode::{self, Decodable, Encodable};
  20 use bitcoin::util::hash::BitcoinHash;
  21 use bitcoin::util::bip143;
  22
  23 use bitcoin_hashes::Hash;
  24 use bitcoin_hashes::sha256::Hash as Sha256;
  25 use bitcoin_hashes::hash160::Hash as Hash160;
  26 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
  27
  28 use secp256k1::{Secp256k1,Signature};
  29 use secp256k1::key::{SecretKey,PublicKey};
  30 use secp256k1;
  31
  32 use ln::msgs::DecodeError;
  33 use ln::chan_utils;
  34 use ln::chan_utils::HTLCOutputInCommitment;
  35 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
  36 use ln::channel::{ACCEPTED_HTLC_SCRIPT_WEIGHT, OFFERED_HTLC_SCRIPT_WEIGHT};
  37 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface, FeeEstimator, ConfirmationTarget};
  38 use chain::transaction::OutPoint;
  39 use chain::keysinterface::SpendableOutputDescriptor;
  40 use util::logger::Logger;
  41 use util::ser::{ReadableArgs, Readable, Writer, Writeable, WriterWriteAdaptor, U48};
  42 use util::{byte_utils, events};
  43
  44 use std::collections::{HashMap, hash_map};
  45 use std::sync::{Arc,Mutex};
  46 use std::{hash,cmp, mem};
  47
  48 /// An error enum representing a failure to persist a channel monitor update.
  49 #[derive(Clone)]
  50 pub enum ChannelMonitorUpdateErr {
  51         /// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
  52         /// our state failed, but is expected to succeed at some point in the future).
  53         ///
  54         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  55         /// submitting new commitment transactions to the remote party.
  56         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  57         /// the channel to an operational state.
  58         ///
  59         /// Note that continuing to operate when no copy of the updated ChannelMonitor could be
  60         /// persisted is unsafe - if you failed to store the update on your own local disk you should
  61         /// instead return PermanentFailure to force closure of the channel ASAP.
  62         ///
  63         /// Even when a channel has been "frozen" updates to the ChannelMonitor can continue to occur
  64         /// (eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
  65         /// to claim it on this channel) and those updates must be applied wherever they can be. At
  66         /// least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
  67         /// be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
  68         /// the channel which would invalidate previous ChannelMonitors are not made when a channel has
  69         /// been "frozen".
  70         ///
  71         /// Note that even if updates made after TemporaryFailure succeed you must still call
  72         /// test_restore_channel_monitor to ensure you have the latest monitor and re-enable normal
  73         /// channel operation.
  74         ///
  75         /// For deployments where a copy of ChannelMonitors and other local state are backed up in a
  76         /// remote location (with local copies persisted immediately), it is anticipated that all
  77         /// updates will return TemporaryFailure until the remote copies could be updated.
  78         TemporaryFailure,
  79         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  80         /// different watchtower and cannot update with all watchtowers that were previously informed
  81         /// of this channel). This will force-close the channel in question.
  82         ///
  83         /// Should also be used to indicate a failure to update the local copy of the channel monitor.
  84         PermanentFailure,
  85 }
  86
  87 /// General Err type for ChannelMonitor actions. Generally, this implies that the data provided is
  88 /// inconsistent with the ChannelMonitor being called. eg for ChannelMonitor::insert_combine this
  89 /// means you tried to merge two monitors for different channels or for a channel which was
  90 /// restored from a backup and then generated new commitment updates.
  91 /// Contains a human-readable error message.
  92 #[derive(Debug)]
  93 pub struct MonitorUpdateError(pub &'static str);
  94
  95 /// Simple structure send back by ManyChannelMonitor in case of HTLC detected onchain from a
  96 /// forward channel and from which info are needed to update HTLC in a backward channel.
  97 pub struct HTLCUpdate {
  98         pub(super) payment_hash: PaymentHash,
  99         pub(super) payment_preimage: Option<PaymentPreimage>,
 100         pub(super) source: HTLCSource
 101 }
 102
 103 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
 104 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
 105 /// events to it, while also taking any add_update_monitor events and passing them to some remote
 106 /// server(s).
 107 ///
 108 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
 109 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
 110 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
 111 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
 112 pub trait ManyChannelMonitor: Send + Sync {
 113         /// Adds or updates a monitor for the given `funding_txo`.
 114         ///
 115         /// Implementor must also ensure that the funding_txo outpoint is registered with any relevant
 116         /// ChainWatchInterfaces such that the provided monitor receives block_connected callbacks with
 117         /// any spends of it.
 118         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
 119
 120         /// Used by ChannelManager to get list of HTLC resolved onchain and which needed to be updated
 121         /// with success or failure backward
 122         fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate>;
 123 }
 124
 125 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
 126 /// watchtower or watch our own channels.
 127 ///
 128 /// Note that you must provide your own key by which to refer to channels.
 129 ///
 130 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
 131 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
 132 /// index by a PublicKey which is required to sign any updates.
 133 ///
 134 /// If you're using this for local monitoring of your own channels, you probably want to use
 135 /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation.
 136 pub struct SimpleManyChannelMonitor<Key> {
 137         #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
 138         pub monitors: Mutex<HashMap<Key, ChannelMonitor>>,
 139         #[cfg(not(test))]
 140         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
 141         chain_monitor: Arc<ChainWatchInterface>,
 142         broadcaster: Arc<BroadcasterInterface>,
 143         pending_events: Mutex<Vec<events::Event>>,
 144         pending_htlc_updated: Mutex<HashMap<PaymentHash, Vec<(HTLCSource, Option<PaymentPreimage>)>>>,
 145         logger: Arc<Logger>,
 146         fee_estimator: Arc<FeeEstimator>
 147 }
 148
 149 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
 150         fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
 151                 let block_hash = header.bitcoin_hash();
 152                 let mut new_events: Vec<events::Event> = Vec::with_capacity(0);
 153                 let mut htlc_updated_infos = Vec::new();
 154                 {
 155                         let mut monitors = self.monitors.lock().unwrap();
 156                         for monitor in monitors.values_mut() {
 157                                 let (txn_outputs, spendable_outputs, mut htlc_updated) = monitor.block_connected(txn_matched, height, &block_hash, &*self.broadcaster, &*self.fee_estimator);
 158                                 if spendable_outputs.len() > 0 {
 159                                         new_events.push(events::Event::SpendableOutputs {
 160                                                 outputs: spendable_outputs,
 161                                         });
 162                                 }
 163
 164                                 for (ref txid, ref outputs) in txn_outputs {
 165                                         for (idx, output) in outputs.iter().enumerate() {
 166                                                 self.chain_monitor.install_watch_outpoint((txid.clone(), idx as u32), &output.script_pubkey);
 167                                         }
 168                                 }
 169                                 htlc_updated_infos.append(&mut htlc_updated);
 170                         }
 171                 }
 172                 {
 173                         // ChannelManager will just need to fetch pending_htlc_updated and pass state backward
 174                         let mut pending_htlc_updated = self.pending_htlc_updated.lock().unwrap();
 175                         for htlc in htlc_updated_infos.drain(..) {
 176                                 match pending_htlc_updated.entry(htlc.2) {
 177                                         hash_map::Entry::Occupied(mut e) => {
 178                                                 // In case of reorg we may have htlc outputs solved in a different way so
 179                                                 // we prefer to keep claims but don't store duplicate updates for a given
 180                                                 // (payment_hash, HTLCSource) pair.
 181                                                 // TODO: Note that we currently don't really use this as ChannelManager
 182                                                 // will fail/claim backwards after the first block. We really should delay
 183                                                 // a few blocks before failing backwards (but can claim backwards
 184                                                 // immediately) as long as we have a few blocks of headroom.
 185                                                 let mut existing_claim = false;
 186                                                 e.get_mut().retain(|htlc_data| {
 187                                                         if htlc.0 == htlc_data.0 {
 188                                                                 if htlc_data.1.is_some() {
 189                                                                         existing_claim = true;
 190                                                                         true
 191                                                                 } else { false }
 192                                                         } else { true }
 193                                                 });
 194                                                 if !existing_claim {
 195                                                         e.get_mut().push((htlc.0, htlc.1));
 196                                                 }
 197                                         }
 198                                         hash_map::Entry::Vacant(e) => {
 199                                                 e.insert(vec![(htlc.0, htlc.1)]);
 200                                         }
 201                                 }
 202                         }
 203                 }
 204                 let mut pending_events = self.pending_events.lock().unwrap();
 205                 pending_events.append(&mut new_events);
 206         }
 207
 208         fn block_disconnected(&self, _: &BlockHeader) { }
 209 }
 210
 211 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
 212         /// Creates a new object which can be used to monitor several channels given the chain
 213         /// interface with which to register to receive notifications.
 214         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>, logger: Arc<Logger>, feeest: Arc<FeeEstimator>) -> Arc<SimpleManyChannelMonitor<Key>> {
 215                 let res = Arc::new(SimpleManyChannelMonitor {
 216                         monitors: Mutex::new(HashMap::new()),
 217                         chain_monitor,
 218                         broadcaster,
 219                         pending_events: Mutex::new(Vec::new()),
 220                         pending_htlc_updated: Mutex::new(HashMap::new()),
 221                         logger,
 222                         fee_estimator: feeest,
 223                 });
 224                 let weak_res = Arc::downgrade(&res);
 225                 res.chain_monitor.register_listener(weak_res);
 226                 res
 227         }
 228
 229         /// Adds or updates the monitor which monitors the channel referred to by the given key.
 230         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), MonitorUpdateError> {
 231                 let mut monitors = self.monitors.lock().unwrap();
 232                 match monitors.get_mut(&key) {
 233                         Some(orig_monitor) => {
 234                                 log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(monitor.key_storage));
 235                                 return orig_monitor.insert_combine(monitor);
 236                         },
 237                         None => {}
 238                 };
 239                 match monitor.key_storage {
 240                         Storage::Local { ref funding_info, .. } => {
 241                                 match funding_info {
 242                                         &None => {
 243                                                 return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !"));
 244                                         },
 245                                         &Some((ref outpoint, ref script)) => {
 246                                                 log_trace!(self, "Got new Channel Monitor for channel {}", log_bytes!(outpoint.to_channel_id()[..]));
 247                                                 self.chain_monitor.install_watch_tx(&outpoint.txid, script);
 248                                                 self.chain_monitor.install_watch_outpoint((outpoint.txid, outpoint.index as u32), script);
 249                                         },
 250                                 }
 251                         },
 252                         Storage::Watchtower { .. } => {
 253                                 self.chain_monitor.watch_all_txn();
 254                         }
 255                 }
 256                 monitors.insert(key, monitor);
 257                 Ok(())
 258         }
 259 }
 260
 261 impl ManyChannelMonitor for SimpleManyChannelMonitor<OutPoint> {
 262         fn add_update_monitor(&self, funding_txo: OutPoint, monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 263                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 264                         Ok(_) => Ok(()),
 265                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 266                 }
 267         }
 268
 269         fn fetch_pending_htlc_updated(&self) -> Vec<HTLCUpdate> {
 270                 let mut updated = self.pending_htlc_updated.lock().unwrap();
 271                 let mut pending_htlcs_updated = Vec::with_capacity(updated.len());
 272                 for (k, v) in updated.drain() {
 273                         for htlc_data in v {
 274                                 pending_htlcs_updated.push(HTLCUpdate {
 275                                         payment_hash: k,
 276                                         payment_preimage: htlc_data.1,
 277                                         source: htlc_data.0,
 278                                 });
 279                         }
 280                 }
 281                 pending_htlcs_updated
 282         }
 283 }
 284
 285 impl<Key : Send + cmp::Eq + hash::Hash> events::EventsProvider for SimpleManyChannelMonitor<Key> {
 286         fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
 287                 let mut pending_events = self.pending_events.lock().unwrap();
 288                 let mut ret = Vec::new();
 289                 mem::swap(&mut ret, &mut *pending_events);
 290                 ret
 291         }
 292 }
 293
 294 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 295 /// instead claiming it in its own individual transaction.
 296 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 297 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 298 /// HTLC-Success transaction.
 299 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
 300 /// transaction confirmed (and we use it in a few more, equivalent, places).
 301 pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
 302 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
 303 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
 304 /// copies of ChannelMonitors, including watchtowers).
 305 pub(crate) const HTLC_FAIL_TIMEOUT_BLOCKS: u32 = 3;
 306 /// Number of blocks we wait on seeing a confirmed HTLC-Timeout or previous revoked commitment
 307 /// transaction before we fail corresponding inbound HTLCs. This prevents us from failing backwards
 308 /// and then getting a reorg resulting in us losing money.
 309 //TODO: We currently don't actually use this...we should
 310 pub(crate) const HTLC_FAIL_ANTI_REORG_DELAY: u32 = 6;
 311
 312 #[derive(Clone, PartialEq)]
 313 enum Storage {
 314         Local {
 315                 revocation_base_key: SecretKey,
 316                 htlc_base_key: SecretKey,
 317                 delayed_payment_base_key: SecretKey,
 318                 payment_base_key: SecretKey,
 319                 shutdown_pubkey: PublicKey,
 320                 prev_latest_per_commitment_point: Option<PublicKey>,
 321                 latest_per_commitment_point: Option<PublicKey>,
 322                 funding_info: Option<(OutPoint, Script)>,
 323                 current_remote_commitment_txid: Option<Sha256dHash>,
 324                 prev_remote_commitment_txid: Option<Sha256dHash>,
 325         },
 326         Watchtower {
 327                 revocation_base_key: PublicKey,
 328                 htlc_base_key: PublicKey,
 329         }
 330 }
 331
 332 #[derive(Clone, PartialEq)]
 333 struct LocalSignedTx {
 334         /// txid of the transaction in tx, just used to make comparison faster
 335         txid: Sha256dHash,
 336         tx: Transaction,
 337         revocation_key: PublicKey,
 338         a_htlc_key: PublicKey,
 339         b_htlc_key: PublicKey,
 340         delayed_payment_key: PublicKey,
 341         feerate_per_kw: u64,
 342         htlc_outputs: Vec<(HTLCOutputInCommitment, Option<(Signature, Signature)>, Option<HTLCSource>)>,
 343 }
 344
 345 #[derive(PartialEq)]
 346 enum InputDescriptors {
 347         RevokedOfferedHTLC,
 348         RevokedReceivedHTLC,
 349         OfferedHTLC,
 350         ReceivedHTLC,
 351         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 352 }
 353
 354 const SERIALIZATION_VERSION: u8 = 1;
 355 const MIN_SERIALIZATION_VERSION: u8 = 1;
 356
 357 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
 358 /// on-chain transactions to ensure no loss of funds occurs.
 359 ///
 360 /// You MUST ensure that no ChannelMonitors for a given channel anywhere contain out-of-date
 361 /// information and are actively monitoring the chain.
 362 #[derive(Clone)]
 363 pub struct ChannelMonitor {
 364         commitment_transaction_number_obscure_factor: u64,
 365
 366         key_storage: Storage,
 367         their_htlc_base_key: Option<PublicKey>,
 368         their_delayed_payment_base_key: Option<PublicKey>,
 369         // first is the idx of the first of the two revocation points
 370         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 371
 372         our_to_self_delay: u16,
 373         their_to_self_delay: Option<u16>,
 374
 375         old_secrets: [([u8; 32], u64); 49],
 376         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>>,
 377         /// We cannot identify HTLC-Success or HTLC-Timeout transactions by themselves on the chain.
 378         /// Nor can we figure out their commitment numbers without the commitment transaction they are
 379         /// spending. Thus, in order to claim them via revocation key, we track all the remote
 380         /// commitment transactions which we find on-chain, mapping them to the commitment number which
 381         /// can be used to derive the revocation key and claim the transactions.
 382         remote_commitment_txn_on_chain: HashMap<Sha256dHash, (u64, Vec<Script>)>,
 383         /// Cache used to make pruning of payment_preimages faster.
 384         /// Maps payment_hash values to commitment numbers for remote transactions for non-revoked
 385         /// remote transactions (ie should remain pretty small).
 386         /// Serialized to disk but should generally not be sent to Watchtowers.
 387         remote_hash_commitment_number: HashMap<PaymentHash, u64>,
 388
 389         // We store two local commitment transactions to avoid any race conditions where we may update
 390         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 391         // various monitors for one channel being out of sync, and us broadcasting a local
 392         // transaction for which we have deleted claim information on some watchtowers.
 393         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 394         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 395
 396         // Used just for ChannelManager to make sure it has the latest channel data during
 397         // deserialization
 398         current_remote_commitment_number: u64,
 399
 400         payment_preimages: HashMap<PaymentHash, PaymentPreimage>,
 401
 402         destination_script: Script,
 403
 404         // We simply modify last_block_hash in Channel's block_connected so that serialization is
 405         // consistent but hopefully the users' copy handles block_connected in a consistent way.
 406         // (we do *not*, however, update them in insert_combine to ensure any local user copies keep
 407         // their last_block_hash from its state and not based on updated copies that didn't run through
 408         // the full block_connected).
 409         pub(crate) last_block_hash: Sha256dHash,
 410         secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 411         logger: Arc<Logger>,
 412 }
 413
 414 #[cfg(any(test, feature = "fuzztarget"))]
 415 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 416 /// underlying object
 417 impl PartialEq for ChannelMonitor {
 418         fn eq(&self, other: &Self) -> bool {
 419                 if self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
 420                         self.key_storage != other.key_storage ||
 421                         self.their_htlc_base_key != other.their_htlc_base_key ||
 422                         self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 423                         self.their_cur_revocation_points != other.their_cur_revocation_points ||
 424                         self.our_to_self_delay != other.our_to_self_delay ||
 425                         self.their_to_self_delay != other.their_to_self_delay ||
 426                         self.remote_claimable_outpoints != other.remote_claimable_outpoints ||
 427                         self.remote_commitment_txn_on_chain != other.remote_commitment_txn_on_chain ||
 428                         self.remote_hash_commitment_number != other.remote_hash_commitment_number ||
 429                         self.prev_local_signed_commitment_tx != other.prev_local_signed_commitment_tx ||
 430                         self.current_remote_commitment_number != other.current_remote_commitment_number ||
 431                         self.current_local_signed_commitment_tx != other.current_local_signed_commitment_tx ||
 432                         self.payment_preimages != other.payment_preimages ||
 433                         self.destination_script != other.destination_script
 434                 {
 435                         false
 436                 } else {
 437                         for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 438                                 if secret != o_secret || idx != o_idx {
 439                                         return false
 440                                 }
 441                         }
 442                         true
 443                 }
 444         }
 445 }
 446
 447 impl ChannelMonitor {
 448         pub(super) fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey, payment_base_key: &SecretKey, shutdown_pubkey: &PublicKey, our_to_self_delay: u16, destination_script: Script, logger: Arc<Logger>) -> ChannelMonitor {
 449                 ChannelMonitor {
 450                         commitment_transaction_number_obscure_factor: 0,
 451
 452                         key_storage: Storage::Local {
 453                                 revocation_base_key: revocation_base_key.clone(),
 454                                 htlc_base_key: htlc_base_key.clone(),
 455                                 delayed_payment_base_key: delayed_payment_base_key.clone(),
 456                                 payment_base_key: payment_base_key.clone(),
 457                                 shutdown_pubkey: shutdown_pubkey.clone(),
 458                                 prev_latest_per_commitment_point: None,
 459                                 latest_per_commitment_point: None,
 460                                 funding_info: None,
 461                                 current_remote_commitment_txid: None,
 462                                 prev_remote_commitment_txid: None,
 463                         },
 464                         their_htlc_base_key: None,
 465                         their_delayed_payment_base_key: None,
 466                         their_cur_revocation_points: None,
 467
 468                         our_to_self_delay: our_to_self_delay,
 469                         their_to_self_delay: None,
 470
 471                         old_secrets: [([0; 32], 1 << 48); 49],
 472                         remote_claimable_outpoints: HashMap::new(),
 473                         remote_commitment_txn_on_chain: HashMap::new(),
 474                         remote_hash_commitment_number: HashMap::new(),
 475
 476                         prev_local_signed_commitment_tx: None,
 477                         current_local_signed_commitment_tx: None,
 478                         current_remote_commitment_number: 1 << 48,
 479
 480                         payment_preimages: HashMap::new(),
 481                         destination_script: destination_script,
 482
 483                         last_block_hash: Default::default(),
 484                         secp_ctx: Secp256k1::new(),
 485                         logger,
 486                 }
 487         }
 488
 489         fn get_witnesses_weight(inputs: &[InputDescriptors]) -> u64 {
 490                 let mut tx_weight = 2; // count segwit flags
 491                 for inp in inputs {
 492                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 493                         tx_weight +=  match inp {
 494                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 495                                 &InputDescriptors::RevokedOfferedHTLC => {
 496                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 497                                 },
 498                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 499                                 &InputDescriptors::RevokedReceivedHTLC => {
 500                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 501                                 },
 502                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 503                                 &InputDescriptors::OfferedHTLC => {
 504                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 505                                 },
 506                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 507                                 &InputDescriptors::ReceivedHTLC => {
 508                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 509                                 },
 510                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 511                                 &InputDescriptors::RevokedOutput => {
 512                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 513                                 },
 514                         };
 515                 }
 516                 tx_weight
 517         }
 518
 519         #[inline]
 520         fn place_secret(idx: u64) -> u8 {
 521                 for i in 0..48 {
 522                         if idx & (1 << i) == (1 << i) {
 523                                 return i
 524                         }
 525                 }
 526                 48
 527         }
 528
 529         #[inline]
 530         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 531                 let mut res: [u8; 32] = secret;
 532                 for i in 0..bits {
 533                         let bitpos = bits - 1 - i;
 534                         if idx & (1 << bitpos) == (1 << bitpos) {
 535                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 536                                 res = Sha256::hash(&res).into_inner();
 537                         }
 538                 }
 539                 res
 540         }
 541
 542         /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
 543         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 544         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 545         pub(super) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
 546                 let pos = ChannelMonitor::place_secret(idx);
 547                 for i in 0..pos {
 548                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 549                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 550                                 return Err(MonitorUpdateError("Previous secret did not match new one"));
 551                         }
 552                 }
 553                 if self.get_min_seen_secret() <= idx {
 554                         return Ok(());
 555                 }
 556                 self.old_secrets[pos as usize] = (secret, idx);
 557
 558                 // Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
 559                 // events for now-revoked/fulfilled HTLCs.
 560                 // TODO: We should probably consider whether we're really getting the next secret here.
 561                 if let Storage::Local { ref mut prev_remote_commitment_txid, .. } = self.key_storage {
 562                         if let Some(txid) = prev_remote_commitment_txid.take() {
 563                                 for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
 564                                         *source = None;
 565                                 }
 566                         }
 567                 }
 568
 569                 if !self.payment_preimages.is_empty() {
 570                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 571                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 572                         let min_idx = self.get_min_seen_secret();
 573                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 574
 575                         self.payment_preimages.retain(|&k, _| {
 576                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 577                                         if k == htlc.payment_hash {
 578                                                 return true
 579                                         }
 580                                 }
 581                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 582                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 583                                                 if k == htlc.payment_hash {
 584                                                         return true
 585                                                 }
 586                                         }
 587                                 }
 588                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 589                                         if *cn < min_idx {
 590                                                 return true
 591                                         }
 592                                         true
 593                                 } else { false };
 594                                 if contains {
 595                                         remote_hash_commitment_number.remove(&k);
 596                                 }
 597                                 false
 598                         });
 599                 }
 600
 601                 Ok(())
 602         }
 603
 604         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 605         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 606         /// possibly future revocation/preimage information) to claim outputs where possible.
 607         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 608         pub(super) fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey) {
 609                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 610                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 611                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 612                 // timeouts)
 613                 for &(ref htlc, _) in &htlc_outputs {
 614                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 615                 }
 616
 617                 let new_txid = unsigned_commitment_tx.txid();
 618                 log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
 619                 log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
 620                 if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage {
 621                         *prev_remote_commitment_txid = current_remote_commitment_txid.take();
 622                         *current_remote_commitment_txid = Some(new_txid);
 623                 }
 624                 self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
 625                 self.current_remote_commitment_number = commitment_number;
 626                 //TODO: Merge this into the other per-remote-transaction output storage stuff
 627                 match self.their_cur_revocation_points {
 628                         Some(old_points) => {
 629                                 if old_points.0 == commitment_number + 1 {
 630                                         self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(their_revocation_point)));
 631                                 } else if old_points.0 == commitment_number + 2 {
 632                                         if let Some(old_second_point) = old_points.2 {
 633                                                 self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(their_revocation_point)));
 634                                         } else {
 635                                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
 636                                         }
 637                                 } else {
 638                                         self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
 639                                 }
 640                         },
 641                         None => {
 642                                 self.their_cur_revocation_points = Some((commitment_number, their_revocation_point, None));
 643                         }
 644                 }
 645         }
 646
 647         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 648         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 649         /// is important that any clones of this channel monitor (including remote clones) by kept
 650         /// up-to-date as our local commitment transaction is updated.
 651         /// Panics if set_their_to_self_delay has never been called.
 652         /// Also update Storage with latest local per_commitment_point to derive local_delayedkey in
 653         /// case of onchain HTLC tx
 654         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, Option<(Signature, Signature)>, Option<HTLCSource>)>) {
 655                 assert!(self.their_to_self_delay.is_some());
 656                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 657                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 658                         txid: signed_commitment_tx.txid(),
 659                         tx: signed_commitment_tx,
 660                         revocation_key: local_keys.revocation_key,
 661                         a_htlc_key: local_keys.a_htlc_key,
 662                         b_htlc_key: local_keys.b_htlc_key,
 663                         delayed_payment_key: local_keys.a_delayed_payment_key,
 664                         feerate_per_kw,
 665                         htlc_outputs,
 666                 });
 667
 668                 if let Storage::Local { ref mut latest_per_commitment_point, .. } = self.key_storage {
 669                         *latest_per_commitment_point = Some(local_keys.per_commitment_point);
 670                 } else {
 671                         panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
 672                 }
 673         }
 674
 675         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 676         /// commitment_tx_infos which contain the payment hash have been revoked.
 677         pub(super) fn provide_payment_preimage(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage) {
 678                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 679         }
 680
 681         /// Combines this ChannelMonitor with the information contained in the other ChannelMonitor.
 682         /// After a successful call this ChannelMonitor is up-to-date and is safe to use to monitor the
 683         /// chain for new blocks/transactions.
 684         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), MonitorUpdateError> {
 685                 match self.key_storage {
 686                         Storage::Local { ref funding_info, .. } => {
 687                                 if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
 688                                 let our_funding_info = funding_info;
 689                                 if let Storage::Local { ref funding_info, .. } = other.key_storage {
 690                                         if funding_info.is_none() { return Err(MonitorUpdateError("Try to combine a Local monitor without funding_info")); }
 691                                         // We should be able to compare the entire funding_txo, but in fuzztarget it's trivially
 692                                         // easy to collide the funding_txo hash and have a different scriptPubKey.
 693                                         if funding_info.as_ref().unwrap().0 != our_funding_info.as_ref().unwrap().0 {
 694                                                 return Err(MonitorUpdateError("Funding transaction outputs are not identical!"));
 695                                         }
 696                                 } else {
 697                                         return Err(MonitorUpdateError("Try to combine a Local monitor with a Watchtower one !"));
 698                                 }
 699                         },
 700                         Storage::Watchtower { .. } => {
 701                                 if let Storage::Watchtower { .. } = other.key_storage {
 702                                         unimplemented!();
 703                                 } else {
 704                                         return Err(MonitorUpdateError("Try to combine a Watchtower monitor with a Local one !"));
 705                                 }
 706                         },
 707                 }
 708                 let other_min_secret = other.get_min_seen_secret();
 709                 let our_min_secret = self.get_min_seen_secret();
 710                 if our_min_secret > other_min_secret {
 711                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap())?;
 712                 }
 713                 if let Some(ref local_tx) = self.current_local_signed_commitment_tx {
 714                         if let Some(ref other_local_tx) = other.current_local_signed_commitment_tx {
 715                                 let our_commitment_number = 0xffffffffffff - ((((local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor);
 716                                 let other_commitment_number = 0xffffffffffff - ((((other_local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (other_local_tx.tx.lock_time as u64 & 0xffffff)) ^ other.commitment_transaction_number_obscure_factor);
 717                                 if our_commitment_number >= other_commitment_number {
 718                                         self.key_storage = other.key_storage;
 719                                 }
 720                         }
 721                 }
 722                 // TODO: We should use current_remote_commitment_number and the commitment number out of
 723                 // local transactions to decide how to merge
 724                 if our_min_secret >= other_min_secret {
 725                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 726                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 727                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 728                         }
 729                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 730                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 731                         }
 732                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 733                                 self.current_local_signed_commitment_tx = Some(local_tx);
 734                         }
 735                         self.payment_preimages = other.payment_preimages;
 736                 }
 737
 738                 self.current_remote_commitment_number = cmp::min(self.current_remote_commitment_number, other.current_remote_commitment_number);
 739                 Ok(())
 740         }
 741
 742         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 743         pub(super) fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 744                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 745                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 746         }
 747
 748         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 749         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 750         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 751         /// provides slightly better privacy.
 752         /// It's the responsibility of the caller to register outpoint and script with passing the former
 753         /// value as key to add_update_monitor.
 754         pub(super) fn set_funding_info(&mut self, new_funding_info: (OutPoint, Script)) {
 755                 match self.key_storage {
 756                         Storage::Local { ref mut funding_info, .. } => {
 757                                 *funding_info = Some(new_funding_info);
 758                         },
 759                         Storage::Watchtower { .. } => {
 760                                 panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
 761                         }
 762                 }
 763         }
 764
 765         /// We log these base keys at channel opening to being able to rebuild redeemscript in case of leaked revoked commit tx
 766         pub(super) fn set_their_base_keys(&mut self, their_htlc_base_key: &PublicKey, their_delayed_payment_base_key: &PublicKey) {
 767                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 768                 self.their_delayed_payment_base_key = Some(their_delayed_payment_base_key.clone());
 769         }
 770
 771         pub(super) fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 772                 self.their_to_self_delay = Some(their_to_self_delay);
 773         }
 774
 775         pub(super) fn unset_funding_info(&mut self) {
 776                 match self.key_storage {
 777                         Storage::Local { ref mut funding_info, .. } => {
 778                                 *funding_info = None;
 779                         },
 780                         Storage::Watchtower { .. } => {
 781                                 panic!("Channel somehow ended up with its internal ChannelMonitor being in Watchtower mode?");
 782                         },
 783                 }
 784         }
 785
 786         /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
 787         pub fn get_funding_txo(&self) -> Option<OutPoint> {
 788                 match self.key_storage {
 789                         Storage::Local { ref funding_info, .. } => {
 790                                 match funding_info {
 791                                         &Some((outpoint, _)) => Some(outpoint),
 792                                         &None => None
 793                                 }
 794                         },
 795                         Storage::Watchtower { .. } => {
 796                                 return None;
 797                         }
 798                 }
 799         }
 800
 801         /// Gets the sets of all outpoints which this ChannelMonitor expects to hear about spends of.
 802         /// Generally useful when deserializing as during normal operation the return values of
 803         /// block_connected are sufficient to ensure all relevant outpoints are being monitored (note
 804         /// that the get_funding_txo outpoint and transaction must also be monitored for!).
 805         pub fn get_monitored_outpoints(&self) -> Vec<(Sha256dHash, u32, &Script)> {
 806                 let mut res = Vec::with_capacity(self.remote_commitment_txn_on_chain.len() * 2);
 807                 for (ref txid, &(_, ref outputs)) in self.remote_commitment_txn_on_chain.iter() {
 808                         for (idx, output) in outputs.iter().enumerate() {
 809                                 res.push(((*txid).clone(), idx as u32, output));
 810                         }
 811                 }
 812                 res
 813         }
 814
 815         /// Serializes into a vec, with various modes for the exposed pub fns
 816         fn write<W: Writer>(&self, writer: &mut W, for_local_storage: bool) -> Result<(), ::std::io::Error> {
 817                 //TODO: We still write out all the serialization here manually instead of using the fancy
 818                 //serialization framework we have, we should migrate things over to it.
 819                 writer.write_all(&[SERIALIZATION_VERSION; 1])?;
 820                 writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
 821
 822                 // Set in initial Channel-object creation, so should always be set by now:
 823                 U48(self.commitment_transaction_number_obscure_factor).write(writer)?;
 824
 825                 macro_rules! write_option {
 826                         ($thing: expr) => {
 827                                 match $thing {
 828                                         &Some(ref t) => {
 829                                                 1u8.write(writer)?;
 830                                                 t.write(writer)?;
 831                                         },
 832                                         &None => 0u8.write(writer)?,
 833                                 }
 834                         }
 835                 }
 836
 837                 match self.key_storage {
 838                         Storage::Local { ref revocation_base_key, ref htlc_base_key, ref delayed_payment_base_key, ref payment_base_key, ref shutdown_pubkey, ref prev_latest_per_commitment_point, ref latest_per_commitment_point, ref funding_info, ref current_remote_commitment_txid, ref prev_remote_commitment_txid } => {
 839                                 writer.write_all(&[0; 1])?;
 840                                 writer.write_all(&revocation_base_key[..])?;
 841                                 writer.write_all(&htlc_base_key[..])?;
 842                                 writer.write_all(&delayed_payment_base_key[..])?;
 843                                 writer.write_all(&payment_base_key[..])?;
 844                                 writer.write_all(&shutdown_pubkey.serialize())?;
 845                                 if let Some(ref prev_latest_per_commitment_point) = *prev_latest_per_commitment_point {
 846                                         writer.write_all(&[1; 1])?;
 847                                         writer.write_all(&prev_latest_per_commitment_point.serialize())?;
 848                                 } else {
 849                                         writer.write_all(&[0; 1])?;
 850                                 }
 851                                 if let Some(ref latest_per_commitment_point) = *latest_per_commitment_point {
 852                                         writer.write_all(&[1; 1])?;
 853                                         writer.write_all(&latest_per_commitment_point.serialize())?;
 854                                 } else {
 855                                         writer.write_all(&[0; 1])?;
 856                                 }
 857                                 match funding_info  {
 858                                         &Some((ref outpoint, ref script)) => {
 859                                                 writer.write_all(&outpoint.txid[..])?;
 860                                                 writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
 861                                                 script.write(writer)?;
 862                                         },
 863                                         &None => {
 864                                                 debug_assert!(false, "Try to serialize a useless Local monitor !");
 865                                         },
 866                                 }
 867                                 write_option!(current_remote_commitment_txid);
 868                                 write_option!(prev_remote_commitment_txid);
 869                         },
 870                         Storage::Watchtower { .. } => unimplemented!(),
 871                 }
 872
 873                 writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
 874                 writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
 875
 876                 match self.their_cur_revocation_points {
 877                         Some((idx, pubkey, second_option)) => {
 878                                 writer.write_all(&byte_utils::be48_to_array(idx))?;
 879                                 writer.write_all(&pubkey.serialize())?;
 880                                 match second_option {
 881                                         Some(second_pubkey) => {
 882                                                 writer.write_all(&second_pubkey.serialize())?;
 883                                         },
 884                                         None => {
 885                                                 writer.write_all(&[0; 33])?;
 886                                         },
 887                                 }
 888                         },
 889                         None => {
 890                                 writer.write_all(&byte_utils::be48_to_array(0))?;
 891                         },
 892                 }
 893
 894                 writer.write_all(&byte_utils::be16_to_array(self.our_to_self_delay))?;
 895                 writer.write_all(&byte_utils::be16_to_array(self.their_to_self_delay.unwrap()))?;
 896
 897                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 898                         writer.write_all(secret)?;
 899                         writer.write_all(&byte_utils::be64_to_array(*idx))?;
 900                 }
 901
 902                 macro_rules! serialize_htlc_in_commitment {
 903                         ($htlc_output: expr) => {
 904                                 writer.write_all(&[$htlc_output.offered as u8; 1])?;
 905                                 writer.write_all(&byte_utils::be64_to_array($htlc_output.amount_msat))?;
 906                                 writer.write_all(&byte_utils::be32_to_array($htlc_output.cltv_expiry))?;
 907                                 writer.write_all(&$htlc_output.payment_hash.0[..])?;
 908                                 write_option!(&$htlc_output.transaction_output_index);
 909                         }
 910                 }
 911
 912                 writer.write_all(&byte_utils::be64_to_array(self.remote_claimable_outpoints.len() as u64))?;
 913                 for (ref txid, ref htlc_infos) in self.remote_claimable_outpoints.iter() {
 914                         writer.write_all(&txid[..])?;
 915                         writer.write_all(&byte_utils::be64_to_array(htlc_infos.len() as u64))?;
 916                         for &(ref htlc_output, ref htlc_source) in htlc_infos.iter() {
 917                                 serialize_htlc_in_commitment!(htlc_output);
 918                                 write_option!(htlc_source);
 919                         }
 920                 }
 921
 922                 writer.write_all(&byte_utils::be64_to_array(self.remote_commitment_txn_on_chain.len() as u64))?;
 923                 for (ref txid, &(commitment_number, ref txouts)) in self.remote_commitment_txn_on_chain.iter() {
 924                         writer.write_all(&txid[..])?;
 925                         writer.write_all(&byte_utils::be48_to_array(commitment_number))?;
 926                         (txouts.len() as u64).write(writer)?;
 927                         for script in txouts.iter() {
 928                                 script.write(writer)?;
 929                         }
 930                 }
 931
 932                 if for_local_storage {
 933                         writer.write_all(&byte_utils::be64_to_array(self.remote_hash_commitment_number.len() as u64))?;
 934                         for (ref payment_hash, commitment_number) in self.remote_hash_commitment_number.iter() {
 935                                 writer.write_all(&payment_hash.0[..])?;
 936                                 writer.write_all(&byte_utils::be48_to_array(*commitment_number))?;
 937                         }
 938                 } else {
 939                         writer.write_all(&byte_utils::be64_to_array(0))?;
 940                 }
 941
 942                 macro_rules! serialize_local_tx {
 943                         ($local_tx: expr) => {
 944                                 if let Err(e) = $local_tx.tx.consensus_encode(&mut WriterWriteAdaptor(writer)) {
 945                                         match e {
 946                                                 encode::Error::Io(e) => return Err(e),
 947                                                 _ => panic!("local tx must have been well-formed!"),
 948                                         }
 949                                 }
 950
 951                                 writer.write_all(&$local_tx.revocation_key.serialize())?;
 952                                 writer.write_all(&$local_tx.a_htlc_key.serialize())?;
 953                                 writer.write_all(&$local_tx.b_htlc_key.serialize())?;
 954                                 writer.write_all(&$local_tx.delayed_payment_key.serialize())?;
 955
 956                                 writer.write_all(&byte_utils::be64_to_array($local_tx.feerate_per_kw))?;
 957                                 writer.write_all(&byte_utils::be64_to_array($local_tx.htlc_outputs.len() as u64))?;
 958                                 for &(ref htlc_output, ref sigs, ref htlc_source) in $local_tx.htlc_outputs.iter() {
 959                                         serialize_htlc_in_commitment!(htlc_output);
 960                                         if let &Some((ref their_sig, ref our_sig)) = sigs {
 961                                                 1u8.write(writer)?;
 962                                                 writer.write_all(&their_sig.serialize_compact())?;
 963                                                 writer.write_all(&our_sig.serialize_compact())?;
 964                                         } else {
 965                                                 0u8.write(writer)?;
 966                                         }
 967                                         write_option!(htlc_source);
 968                                 }
 969                         }
 970                 }
 971
 972                 if let Some(ref prev_local_tx) = self.prev_local_signed_commitment_tx {
 973                         writer.write_all(&[1; 1])?;
 974                         serialize_local_tx!(prev_local_tx);
 975                 } else {
 976                         writer.write_all(&[0; 1])?;
 977                 }
 978
 979                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 980                         writer.write_all(&[1; 1])?;
 981                         serialize_local_tx!(cur_local_tx);
 982                 } else {
 983                         writer.write_all(&[0; 1])?;
 984                 }
 985
 986                 if for_local_storage {
 987                         writer.write_all(&byte_utils::be48_to_array(self.current_remote_commitment_number))?;
 988                 } else {
 989                         writer.write_all(&byte_utils::be48_to_array(0))?;
 990                 }
 991
 992                 writer.write_all(&byte_utils::be64_to_array(self.payment_preimages.len() as u64))?;
 993                 for payment_preimage in self.payment_preimages.values() {
 994                         writer.write_all(&payment_preimage.0[..])?;
 995                 }
 996
 997                 self.last_block_hash.write(writer)?;
 998                 self.destination_script.write(writer)?;
 999
1000                 Ok(())
1001         }
1002
1003         /// Writes this monitor into the given writer, suitable for writing to disk.
1004         ///
1005         /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1006         /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1007         /// the "reorg path" (ie not just starting at the same height but starting at the highest
1008         /// common block that appears on your best chain as well as on the chain which contains the
1009         /// last block hash returned) upon deserializing the object!
1010         pub fn write_for_disk<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1011                 self.write(writer, true)
1012         }
1013
1014         /// Encodes this monitor into the given writer, suitable for sending to a remote watchtower
1015         ///
1016         /// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
1017         /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
1018         /// the "reorg path" (ie not just starting at the same height but starting at the highest
1019         /// common block that appears on your best chain as well as on the chain which contains the
1020         /// last block hash returned) upon deserializing the object!
1021         pub fn write_for_watchtower<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
1022                 self.write(writer, false)
1023         }
1024
1025         /// Can only fail if idx is < get_min_seen_secret
1026         pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
1027                 for i in 0..self.old_secrets.len() {
1028                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
1029                                 return Some(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
1030                         }
1031                 }
1032                 assert!(idx < self.get_min_seen_secret());
1033                 None
1034         }
1035
1036         pub(super) fn get_min_seen_secret(&self) -> u64 {
1037                 //TODO This can be optimized?
1038                 let mut min = 1 << 48;
1039                 for &(_, idx) in self.old_secrets.iter() {
1040                         if idx < min {
1041                                 min = idx;
1042                         }
1043                 }
1044                 min
1045         }
1046
1047         pub(super) fn get_cur_remote_commitment_number(&self) -> u64 {
1048                 self.current_remote_commitment_number
1049         }
1050
1051         pub(super) fn get_cur_local_commitment_number(&self) -> u64 {
1052                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1053                         0xffff_ffff_ffff - ((((local_tx.tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (local_tx.tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor)
1054                 } else { 0xffff_ffff_ffff }
1055         }
1056
1057         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
1058         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
1059         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
1060         /// HTLC-Success/HTLC-Timeout transactions.
1061         /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
1062         /// revoked remote commitment tx
1063         fn check_spend_remote_transaction(&mut self, tx: &Transaction, height: u32, fee_estimator: &FeeEstimator) -> (Vec<Transaction>, (Sha256dHash, Vec<TxOut>), Vec<SpendableOutputDescriptor>, Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)>)  {
1064                 // Most secp and related errors trying to create keys means we have no hope of constructing
1065                 // a spend transaction...so we return no transactions to broadcast
1066                 let mut txn_to_broadcast = Vec::new();
1067                 let mut watch_outputs = Vec::new();
1068                 let mut spendable_outputs = Vec::new();
1069                 let mut htlc_updated = Vec::new();
1070
1071                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1072                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
1073
1074                 macro_rules! ignore_error {
1075                         ( $thing : expr ) => {
1076                                 match $thing {
1077                                         Ok(a) => a,
1078                                         Err(_) => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated)
1079                                 }
1080                         };
1081                 }
1082
1083                 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);
1084                 if commitment_number >= self.get_min_seen_secret() {
1085                         let secret = self.get_secret(commitment_number).unwrap();
1086                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1087                         let (revocation_pubkey, b_htlc_key, local_payment_key) = match self.key_storage {
1088                                 Storage::Local { ref revocation_base_key, ref htlc_base_key, ref payment_base_key, .. } => {
1089                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1090                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1091                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))),
1092                                         Some(ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &payment_base_key))))
1093                                 },
1094                                 Storage::Watchtower { ref revocation_base_key, ref htlc_base_key, .. } => {
1095                                         let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1096                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
1097                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)),
1098                                         None)
1099                                 },
1100                         };
1101                         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()));
1102                         let a_htlc_key = match self.their_htlc_base_key {
1103                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated),
1104                                 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)),
1105                         };
1106
1107                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
1108                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1109
1110                         let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key {
1111                                 // Note that the Network here is ignored as we immediately drop the address for the
1112                                 // script_pubkey version.
1113                                 let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
1114                                 Some(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script())
1115                         } else { None };
1116
1117                         let mut total_value = 0;
1118                         let mut values = Vec::new();
1119                         let mut inputs = Vec::new();
1120                         let mut htlc_idxs = Vec::new();
1121                         let mut input_descriptors = Vec::new();
1122
1123                         for (idx, outp) in tx.output.iter().enumerate() {
1124                                 if outp.script_pubkey == revokeable_p2wsh {
1125                                         inputs.push(TxIn {
1126                                                 previous_output: BitcoinOutPoint {
1127                                                         txid: commitment_txid,
1128                                                         vout: idx as u32,
1129                                                 },
1130                                                 script_sig: Script::new(),
1131                                                 sequence: 0xfffffffd,
1132                                                 witness: Vec::new(),
1133                                         });
1134                                         htlc_idxs.push(None);
1135                                         values.push(outp.value);
1136                                         total_value += outp.value;
1137                                         input_descriptors.push(InputDescriptors::RevokedOutput);
1138                                 } else if Some(&outp.script_pubkey) == local_payment_p2wpkh.as_ref() {
1139                                         spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1140                                                 outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1141                                                 key: local_payment_key.unwrap(),
1142                                                 output: outp.clone(),
1143                                         });
1144                                 }
1145                         }
1146
1147                         macro_rules! sign_input {
1148                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
1149                                         {
1150                                                 let (sig, redeemscript) = match self.key_storage {
1151                                                         Storage::Local { ref revocation_base_key, .. } => {
1152                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
1153                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()].0;
1154                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
1155                                                                 };
1156                                                                 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
1157                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1158                                                                 (self.secp_ctx.sign(&sighash, &revocation_key), redeemscript)
1159                                                         },
1160                                                         Storage::Watchtower { .. } => {
1161                                                                 unimplemented!();
1162                                                         }
1163                                                 };
1164                                                 $input.witness.push(sig.serialize_der().to_vec());
1165                                                 $input.witness[0].push(SigHashType::All as u8);
1166                                                 if $htlc_idx.is_none() {
1167                                                         $input.witness.push(vec!(1));
1168                                                 } else {
1169                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
1170                                                 }
1171                                                 $input.witness.push(redeemscript.into_bytes());
1172                                         }
1173                                 }
1174                         }
1175
1176                         if let Some(ref per_commitment_data) = per_commitment_option {
1177                                 inputs.reserve_exact(per_commitment_data.len());
1178
1179                                 for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1180                                         if let Some(transaction_output_index) = htlc.transaction_output_index {
1181                                                 let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1182                                                 if transaction_output_index as usize >= tx.output.len() ||
1183                                                                 tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1184                                                                 tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1185                                                         return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user
1186                                                 }
1187                                                 let input = TxIn {
1188                                                         previous_output: BitcoinOutPoint {
1189                                                                 txid: commitment_txid,
1190                                                                 vout: transaction_output_index,
1191                                                         },
1192                                                         script_sig: Script::new(),
1193                                                         sequence: 0xfffffffd,
1194                                                         witness: Vec::new(),
1195                                                 };
1196                                                 if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1197                                                         inputs.push(input);
1198                                                         htlc_idxs.push(Some(idx));
1199                                                         values.push(tx.output[transaction_output_index as usize].value);
1200                                                         total_value += htlc.amount_msat / 1000;
1201                                                         input_descriptors.push(if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC });
1202                                                 } else {
1203                                                         let mut single_htlc_tx = Transaction {
1204                                                                 version: 2,
1205                                                                 lock_time: 0,
1206                                                                 input: vec![input],
1207                                                                 output: vec!(TxOut {
1208                                                                         script_pubkey: self.destination_script.clone(),
1209                                                                         value: htlc.amount_msat / 1000,
1210                                                                 }),
1211                                                         };
1212                                                         single_htlc_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::RevokedOfferedHTLC } else { InputDescriptors::RevokedReceivedHTLC }])) / 1000;
1213                                                         let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1214                                                         sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
1215                                                         txn_to_broadcast.push(single_htlc_tx);
1216                                                 }
1217                                         }
1218                                 }
1219                         }
1220
1221                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
1222                                 // We're definitely a remote commitment transaction!
1223                                 log_trace!(self, "Got broadcast of revoked remote commitment transaction, generating general spend tx with {} inputs and {} other txn to broadcast", inputs.len(), txn_to_broadcast.len());
1224                                 watch_outputs.append(&mut tx.output.clone());
1225                                 self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1226
1227                                 // TODO: We really should only fail backwards after our revocation claims have been
1228                                 // confirmed, but we also need to do more other tracking of in-flight pre-confirm
1229                                 // on-chain claims, so we can do that at the same time.
1230                                 macro_rules! check_htlc_fails {
1231                                         ($txid: expr, $commitment_tx: expr) => {
1232                                                 if let Some(ref outpoints) = self.remote_claimable_outpoints.get($txid) {
1233                                                         for &(ref htlc, ref source_option) in outpoints.iter() {
1234                                                                 if let &Some(ref source) = source_option {
1235                                                                         log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of revoked remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1236                                                                         htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone()));
1237                                                                 }
1238                                                         }
1239                                                 }
1240                                         }
1241                                 }
1242                                 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1243                                         if let &Some(ref txid) = current_remote_commitment_txid {
1244                                                 check_htlc_fails!(txid, "current");
1245                                         }
1246                                         if let &Some(ref txid) = prev_remote_commitment_txid {
1247                                                 check_htlc_fails!(txid, "remote");
1248                                         }
1249                                 }
1250                                 // No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
1251                         }
1252                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx
1253
1254                         let outputs = vec!(TxOut {
1255                                 script_pubkey: self.destination_script.clone(),
1256                                 value: total_value,
1257                         });
1258                         let mut spend_tx = Transaction {
1259                                 version: 2,
1260                                 lock_time: 0,
1261                                 input: inputs,
1262                                 output: outputs,
1263                         };
1264                         spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..])) / 1000;
1265
1266                         let mut values_drain = values.drain(..);
1267                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1268
1269                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
1270                                 let value = values_drain.next().unwrap();
1271                                 sign_input!(sighash_parts, input, htlc_idx, value);
1272                         }
1273
1274                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1275                                 outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
1276                                 output: spend_tx.output[0].clone(),
1277                         });
1278                         txn_to_broadcast.push(spend_tx);
1279                 } else if let Some(per_commitment_data) = per_commitment_option {
1280                         // While this isn't useful yet, there is a potential race where if a counterparty
1281                         // revokes a state at the same time as the commitment transaction for that state is
1282                         // confirmed, and the watchtower receives the block before the user, the user could
1283                         // upload a new ChannelMonitor with the revocation secret but the watchtower has
1284                         // already processed the block, resulting in the remote_commitment_txn_on_chain entry
1285                         // not being generated by the above conditional. Thus, to be safe, we go ahead and
1286                         // insert it here.
1287                         watch_outputs.append(&mut tx.output.clone());
1288                         self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
1289
1290                         log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
1291
1292                         // TODO: We really should only fail backwards after our revocation claims have been
1293                         // confirmed, but we also need to do more other tracking of in-flight pre-confirm
1294                         // on-chain claims, so we can do that at the same time.
1295                         macro_rules! check_htlc_fails {
1296                                 ($txid: expr, $commitment_tx: expr, $id: tt) => {
1297                                         if let Some(ref latest_outpoints) = self.remote_claimable_outpoints.get($txid) {
1298                                                 $id: for &(ref htlc, ref source_option) in latest_outpoints.iter() {
1299                                                         if let &Some(ref source) = source_option {
1300                                                                 // Check if the HTLC is present in the commitment transaction that was
1301                                                                 // broadcast, but not if it was below the dust limit, which we should
1302                                                                 // fail backwards immediately as there is no way for us to learn the
1303                                                                 // payment_preimage.
1304                                                                 // Note that if the dust limit were allowed to change between
1305                                                                 // commitment transactions we'd want to be check whether *any*
1306                                                                 // broadcastable commitment transaction has the HTLC in it, but it
1307                                                                 // cannot currently change after channel initialization, so we don't
1308                                                                 // need to here.
1309                                                                 for &(ref broadcast_htlc, ref broadcast_source) in per_commitment_data.iter() {
1310                                                                         if broadcast_htlc.transaction_output_index.is_some() && Some(source) == broadcast_source.as_ref() {
1311                                                                                 continue $id;
1312                                                                         }
1313                                                                 }
1314                                                                 log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
1315                                                                 htlc_updated.push(((**source).clone(), None, htlc.payment_hash.clone()));
1316                                                         }
1317                                                 }
1318                                         }
1319                                 }
1320                         }
1321                         if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1322                                 if let &Some(ref txid) = current_remote_commitment_txid {
1323                                         check_htlc_fails!(txid, "current", 'current_loop);
1324                                 }
1325                                 if let &Some(ref txid) = prev_remote_commitment_txid {
1326                                         check_htlc_fails!(txid, "previous", 'prev_loop);
1327                                 }
1328                         }
1329
1330                         if let Some(revocation_points) = self.their_cur_revocation_points {
1331                                 let revocation_point_option =
1332                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
1333                                         else if let Some(point) = revocation_points.2.as_ref() {
1334                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
1335                                         } else { None };
1336                                 if let Some(revocation_point) = revocation_point_option {
1337                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
1338                                                 Storage::Local { ref revocation_base_key, ref htlc_base_key, .. } => {
1339                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key))),
1340                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key))))
1341                                                 },
1342                                                 Storage::Watchtower { ref revocation_base_key, ref htlc_base_key, .. } => {
1343                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
1344                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
1345                                                 },
1346                                         };
1347                                         let a_htlc_key = match self.their_htlc_base_key {
1348                                                 None => return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated),
1349                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
1350                                         };
1351
1352                                         for (idx, outp) in tx.output.iter().enumerate() {
1353                                                 if outp.script_pubkey.is_v0_p2wpkh() {
1354                                                         match self.key_storage {
1355                                                                 Storage::Local { ref payment_base_key, .. } => {
1356                                                                         if let Ok(local_key) = chan_utils::derive_private_key(&self.secp_ctx, &revocation_point, &payment_base_key) {
1357                                                                                 spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WPKH {
1358                                                                                         outpoint: BitcoinOutPoint { txid: commitment_txid, vout: idx as u32 },
1359                                                                                         key: local_key,
1360                                                                                         output: outp.clone(),
1361                                                                                 });
1362                                                                         }
1363                                                                 },
1364                                                                 Storage::Watchtower { .. } => {}
1365                                                         }
1366                                                         break; // Only to_remote ouput is claimable
1367                                                 }
1368                                         }
1369
1370                                         let mut total_value = 0;
1371                                         let mut values = Vec::new();
1372                                         let mut inputs = Vec::new();
1373                                         let mut input_descriptors = Vec::new();
1374
1375                                         macro_rules! sign_input {
1376                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
1377                                                         {
1378                                                                 let (sig, redeemscript) = match self.key_storage {
1379                                                                         Storage::Local { ref htlc_base_key, .. } => {
1380                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize].0;
1381                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1382                                                                                 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]);
1383                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
1384                                                                                 (self.secp_ctx.sign(&sighash, &htlc_key), redeemscript)
1385                                                                         },
1386                                                                         Storage::Watchtower { .. } => {
1387                                                                                 unimplemented!();
1388                                                                         }
1389                                                                 };
1390                                                                 $input.witness.push(sig.serialize_der().to_vec());
1391                                                                 $input.witness[0].push(SigHashType::All as u8);
1392                                                                 $input.witness.push($preimage);
1393                                                                 $input.witness.push(redeemscript.into_bytes());
1394                                                         }
1395                                                 }
1396                                         }
1397
1398                                         for (idx, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
1399                                                 if let Some(transaction_output_index) = htlc.transaction_output_index {
1400                                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
1401                                                         if transaction_output_index as usize >= tx.output.len() ||
1402                                                                         tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
1403                                                                         tx.output[transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
1404                                                                 return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); // Corrupted per_commitment_data, fuck this user
1405                                                         }
1406                                                         if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1407                                                                 let input = TxIn {
1408                                                                         previous_output: BitcoinOutPoint {
1409                                                                                 txid: commitment_txid,
1410                                                                                 vout: transaction_output_index,
1411                                                                         },
1412                                                                         script_sig: Script::new(),
1413                                                                         sequence: idx as u32, // reset to 0xfffffffd in sign_input
1414                                                                         witness: Vec::new(),
1415                                                                 };
1416                                                                 if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
1417                                                                         inputs.push(input);
1418                                                                         values.push((tx.output[transaction_output_index as usize].value, payment_preimage));
1419                                                                         total_value += htlc.amount_msat / 1000;
1420                                                                         input_descriptors.push(if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC });
1421                                                                 } else {
1422                                                                         let mut single_htlc_tx = Transaction {
1423                                                                                 version: 2,
1424                                                                                 lock_time: 0,
1425                                                                                 input: vec![input],
1426                                                                                 output: vec!(TxOut {
1427                                                                                         script_pubkey: self.destination_script.clone(),
1428                                                                                         value: htlc.amount_msat / 1000,
1429                                                                                 }),
1430                                                                         };
1431                                                                         single_htlc_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (single_htlc_tx.get_weight() + Self::get_witnesses_weight(&[if htlc.offered { InputDescriptors::OfferedHTLC } else { InputDescriptors::ReceivedHTLC }])) / 1000;
1432                                                                         let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
1433                                                                         sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.0.to_vec());
1434                                                                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1435                                                                                 outpoint: BitcoinOutPoint { txid: single_htlc_tx.txid(), vout: 0 },
1436                                                                                 output: single_htlc_tx.output[0].clone(),
1437                                                                         });
1438                                                                         txn_to_broadcast.push(single_htlc_tx);
1439                                                                 }
1440                                                         }
1441                                                         if !htlc.offered {
1442                                                                 // TODO: If the HTLC has already expired, potentially merge it with the
1443                                                                 // rest of the claim transaction, as above.
1444                                                                 let input = TxIn {
1445                                                                         previous_output: BitcoinOutPoint {
1446                                                                                 txid: commitment_txid,
1447                                                                                 vout: transaction_output_index,
1448                                                                         },
1449                                                                         script_sig: Script::new(),
1450                                                                         sequence: idx as u32,
1451                                                                         witness: Vec::new(),
1452                                                                 };
1453                                                                 let mut timeout_tx = Transaction {
1454                                                                         version: 2,
1455                                                                         lock_time: htlc.cltv_expiry,
1456                                                                         input: vec![input],
1457                                                                         output: vec!(TxOut {
1458                                                                                 script_pubkey: self.destination_script.clone(),
1459                                                                                 value: htlc.amount_msat / 1000,
1460                                                                         }),
1461                                                                 };
1462                                                                 let sighash_parts = bip143::SighashComponents::new(&timeout_tx);
1463                                                                 sign_input!(sighash_parts, timeout_tx.input[0], htlc.amount_msat / 1000, vec![0]);
1464                                                                 txn_to_broadcast.push(timeout_tx);
1465                                                         }
1466                                                 }
1467                                         }
1468
1469                                         if inputs.is_empty() { return (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated); } // Nothing to be done...probably a false positive/local tx
1470
1471                                         let outputs = vec!(TxOut {
1472                                                 script_pubkey: self.destination_script.clone(),
1473                                                 value: total_value
1474                                         });
1475                                         let mut spend_tx = Transaction {
1476                                                 version: 2,
1477                                                 lock_time: 0,
1478                                                 input: inputs,
1479                                                 output: outputs,
1480                                         };
1481                                         spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&input_descriptors[..])) / 1000;
1482
1483                                         let mut values_drain = values.drain(..);
1484                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1485
1486                                         for input in spend_tx.input.iter_mut() {
1487                                                 let value = values_drain.next().unwrap();
1488                                                 sign_input!(sighash_parts, input, value.0, (value.1).0.to_vec());
1489                                         }
1490
1491                                         spendable_outputs.push(SpendableOutputDescriptor::StaticOutput {
1492                                                 outpoint: BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 },
1493                                                 output: spend_tx.output[0].clone(),
1494                                         });
1495                                         txn_to_broadcast.push(spend_tx);
1496                                 }
1497                         }
1498                 }
1499
1500                 (txn_to_broadcast, (commitment_txid, watch_outputs), spendable_outputs, htlc_updated)
1501         }
1502
1503         /// Attempts to claim a remote HTLC-Success/HTLC-Timeout's outputs using the revocation key
1504         fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64, fee_estimator: &FeeEstimator) -> (Option<Transaction>, Option<SpendableOutputDescriptor>) {
1505                 if tx.input.len() != 1 || tx.output.len() != 1 {
1506                         return (None, None)
1507                 }
1508
1509                 macro_rules! ignore_error {
1510                         ( $thing : expr ) => {
1511                                 match $thing {
1512                                         Ok(a) => a,
1513                                         Err(_) => return (None, None)
1514                                 }
1515                         };
1516                 }
1517
1518                 let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (None, None); };
1519                 let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
1520                 let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
1521                 let revocation_pubkey = match self.key_storage {
1522                         Storage::Local { ref revocation_base_key, .. } => {
1523                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))
1524                         },
1525                         Storage::Watchtower { ref revocation_base_key, .. } => {
1526                                 ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key))
1527                         },
1528                 };
1529                 let delayed_key = match self.their_delayed_payment_base_key {
1530                         None => return (None, None),
1531                         Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
1532                 };
1533                 let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
1534                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1535                 let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
1536
1537                 let mut inputs = Vec::new();
1538                 let mut amount = 0;
1539
1540                 if tx.output[0].script_pubkey == revokeable_p2wsh { //HTLC transactions have one txin, one txout
1541                         inputs.push(TxIn {
1542                                 previous_output: BitcoinOutPoint {
1543                                         txid: htlc_txid,
1544                                         vout: 0,
1545                                 },
1546                                 script_sig: Script::new(),
1547                                 sequence: 0xfffffffd,
1548                                 witness: Vec::new(),
1549                         });
1550                         amount = tx.output[0].value;
1551                 }
1552
1553                 if !inputs.is_empty() {
1554                         let outputs = vec!(TxOut {
1555                                 script_pubkey: self.destination_script.clone(),
1556                                 value: amount
1557                         });
1558
1559                         let mut spend_tx = Transaction {
1560                                 version: 2,
1561                                 lock_time: 0,
1562                                 input: inputs,
1563                                 output: outputs,
1564                         };
1565                         spend_tx.output[0].value -= fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) * (spend_tx.get_weight() + Self::get_witnesses_weight(&vec![InputDescriptors::RevokedOutput])) / 1000;
1566
1567                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
1568
1569                         let sig = match self.key_storage {
1570                                 Storage::Local { ref revocation_base_key, .. } => {
1571                                         let sighash = hash_to_message!(&sighash_parts.sighash_all(&spend_tx.input[0], &redeemscript, amount)[..]);
1572                                         let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
1573                                         self.secp_ctx.sign(&sighash, &revocation_key)
1574                                 }
1575                                 Storage::Watchtower { .. } => {
1576                                         unimplemented!();
1577                                 }
1578                         };
1579                         spend_tx.input[0].witness.push(sig.serialize_der().to_vec());
1580                         spend_tx.input[0].witness[0].push(SigHashType::All as u8);
1581                         spend_tx.input[0].witness.push(vec!(1));
1582                         spend_tx.input[0].witness.push(redeemscript.into_bytes());
1583
1584                         let outpoint = BitcoinOutPoint { txid: spend_tx.txid(), vout: 0 };
1585                         let output = spend_tx.output[0].clone();
1586                         (Some(spend_tx), Some(SpendableOutputDescriptor::StaticOutput { outpoint, output }))
1587                 } else { (None, None) }
1588         }
1589
1590         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx, per_commitment_point: &Option<PublicKey>, delayed_payment_base_key: &Option<SecretKey>) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, Vec<TxOut>) {
1591                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
1592                 let mut spendable_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1593                 let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
1594
1595                 macro_rules! add_dynamic_output {
1596                         ($father_tx: expr, $vout: expr) => {
1597                                 if let Some(ref per_commitment_point) = *per_commitment_point {
1598                                         if let Some(ref delayed_payment_base_key) = *delayed_payment_base_key {
1599                                                 if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, per_commitment_point, delayed_payment_base_key) {
1600                                                         spendable_outputs.push(SpendableOutputDescriptor::DynamicOutputP2WSH {
1601                                                                 outpoint: BitcoinOutPoint { txid: $father_tx.txid(), vout: $vout },
1602                                                                 key: local_delayedkey,
1603                                                                 witness_script: chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.our_to_self_delay, &local_tx.delayed_payment_key),
1604                                                                 to_self_delay: self.our_to_self_delay,
1605                                                                 output: $father_tx.output[$vout as usize].clone(),
1606                                                         });
1607                                                 }
1608                                         }
1609                                 }
1610                         }
1611                 }
1612
1613
1614                 let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
1615                 let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
1616                 for (idx, output) in local_tx.tx.output.iter().enumerate() {
1617                         if output.script_pubkey == revokeable_p2wsh {
1618                                 add_dynamic_output!(local_tx.tx, idx as u32);
1619                                 break;
1620                         }
1621                 }
1622
1623                 for &(ref htlc, ref sigs, _) in local_tx.htlc_outputs.iter() {
1624                         if let Some(transaction_output_index) = htlc.transaction_output_index {
1625                                 if let &Some((ref their_sig, ref our_sig)) = sigs {
1626                                         if htlc.offered {
1627                                                 log_trace!(self, "Broadcasting HTLC-Timeout transaction against local commitment transactions");
1628                                                 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);
1629
1630                                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1631
1632                                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
1633                                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
1634                                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
1635                                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
1636
1637                                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
1638                                                 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());
1639
1640                                                 add_dynamic_output!(htlc_timeout_tx, 0);
1641                                                 res.push(htlc_timeout_tx);
1642                                         } else {
1643                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
1644                                                         log_trace!(self, "Broadcasting HTLC-Success transaction against local commitment transactions");
1645                                                         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);
1646
1647                                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
1648
1649                                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der().to_vec());
1650                                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
1651                                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der().to_vec());
1652                                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
1653
1654                                                         htlc_success_tx.input[0].witness.push(payment_preimage.0.to_vec());
1655                                                         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());
1656
1657                                                         add_dynamic_output!(htlc_success_tx, 0);
1658                                                         res.push(htlc_success_tx);
1659                                                 }
1660                                         }
1661                                         watch_outputs.push(local_tx.tx.output[transaction_output_index as usize].clone());
1662                                 } else { panic!("Should have sigs for non-dust local tx outputs!") }
1663                         }
1664                 }
1665
1666                 (res, spendable_outputs, watch_outputs)
1667         }
1668
1669         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
1670         /// revoked using data in local_claimable_outpoints.
1671         /// Should not be used if check_spend_revoked_transaction succeeds.
1672         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
1673                 let commitment_txid = tx.txid();
1674                 // TODO: If we find a match here we need to fail back HTLCs that weren't included in the
1675                 // broadcast commitment transaction, either because they didn't meet dust or because they
1676                 // weren't yet included in our commitment transaction(s).
1677                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1678                         if local_tx.txid == commitment_txid {
1679                                 log_trace!(self, "Got latest local commitment tx broadcast, searching for available HTLCs to claim");
1680                                 match self.key_storage {
1681                                         Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
1682                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
1683                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1684                                         },
1685                                         Storage::Watchtower { .. } => {
1686                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
1687                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1688                                         }
1689                                 }
1690                         }
1691                 }
1692                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
1693                         if local_tx.txid == commitment_txid {
1694                                 log_trace!(self, "Got previous local commitment tx broadcast, searching for available HTLCs to claim");
1695                                 match self.key_storage {
1696                                         Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
1697                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key));
1698                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1699                                         },
1700                                         Storage::Watchtower { .. } => {
1701                                                 let (local_txn, spendable_outputs, watch_outputs) = self.broadcast_by_local_state(local_tx, &None, &None);
1702                                                 return (local_txn, spendable_outputs, (commitment_txid, watch_outputs));
1703                                         }
1704                                 }
1705                         }
1706                 }
1707                 (Vec::new(), Vec::new(), (commitment_txid, Vec::new()))
1708         }
1709
1710         /// Generate a spendable output event when closing_transaction get registered onchain.
1711         fn check_spend_closing_transaction(&self, tx: &Transaction) -> Option<SpendableOutputDescriptor> {
1712                 if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 {
1713                         match self.key_storage {
1714                                 Storage::Local { ref shutdown_pubkey, .. } =>  {
1715                                         let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
1716                                         let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
1717                                         for (idx, output) in tx.output.iter().enumerate() {
1718                                                 if shutdown_script == output.script_pubkey {
1719                                                         return Some(SpendableOutputDescriptor::StaticOutput {
1720                                                                 outpoint: BitcoinOutPoint { txid: tx.txid(), vout: idx as u32 },
1721                                                                 output: output.clone(),
1722                                                         });
1723                                                 }
1724                                         }
1725                                 }
1726                                 Storage::Watchtower { .. } => {
1727                                         //TODO: we need to ensure an offline client will generate the event when it
1728                                         // comes back online after only the watchtower saw the transaction
1729                                 }
1730                         }
1731                 }
1732                 None
1733         }
1734
1735         /// Used by ChannelManager deserialization to broadcast the latest local state if it's copy of
1736         /// the Channel was out-of-date.
1737         pub(super) fn get_latest_local_commitment_txn(&self) -> Vec<Transaction> {
1738                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
1739                         let mut res = vec![local_tx.tx.clone()];
1740                         match self.key_storage {
1741                                 Storage::Local { ref delayed_payment_base_key, ref prev_latest_per_commitment_point, .. } => {
1742                                         res.append(&mut self.broadcast_by_local_state(local_tx, prev_latest_per_commitment_point, &Some(*delayed_payment_base_key)).0);
1743                                 },
1744                                 _ => panic!("Can only broadcast by local channelmonitor"),
1745                         };
1746                         res
1747                 } else {
1748                         Vec::new()
1749                 }
1750         }
1751
1752         fn block_connected(&mut self, txn_matched: &[&Transaction], height: u32, block_hash: &Sha256dHash, broadcaster: &BroadcasterInterface, fee_estimator: &FeeEstimator)-> (Vec<(Sha256dHash, Vec<TxOut>)>, Vec<SpendableOutputDescriptor>, Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)>) {
1753                 let mut watch_outputs = Vec::new();
1754                 let mut spendable_outputs = Vec::new();
1755                 let mut htlc_updated = Vec::new();
1756                 for tx in txn_matched {
1757                         if tx.input.len() == 1 {
1758                                 // Assuming our keys were not leaked (in which case we're screwed no matter what),
1759                                 // commitment transactions and HTLC transactions will all only ever have one input,
1760                                 // which is an easy way to filter out any potential non-matching txn for lazy
1761                                 // filters.
1762                                 let prevout = &tx.input[0].previous_output;
1763                                 let mut txn: Vec<Transaction> = Vec::new();
1764                                 let funding_txo = match self.key_storage {
1765                                         Storage::Local { ref funding_info, .. } => {
1766                                                 funding_info.clone()
1767                                         }
1768                                         Storage::Watchtower { .. } => {
1769                                                 unimplemented!();
1770                                         }
1771                                 };
1772                                 if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) {
1773                                         let (remote_txn, new_outputs, mut spendable_output, mut updated) = self.check_spend_remote_transaction(tx, height, fee_estimator);
1774                                         txn = remote_txn;
1775                                         spendable_outputs.append(&mut spendable_output);
1776                                         if !new_outputs.1.is_empty() {
1777                                                 watch_outputs.push(new_outputs);
1778                                         }
1779                                         if txn.is_empty() {
1780                                                 let (local_txn, mut spendable_output, new_outputs) = self.check_spend_local_transaction(tx, height);
1781                                                 spendable_outputs.append(&mut spendable_output);
1782                                                 txn = local_txn;
1783                                                 if !new_outputs.1.is_empty() {
1784                                                         watch_outputs.push(new_outputs);
1785                                                 }
1786                                         }
1787                                         if !funding_txo.is_none() && txn.is_empty() {
1788                                                 if let Some(spendable_output) = self.check_spend_closing_transaction(tx) {
1789                                                         spendable_outputs.push(spendable_output);
1790                                                 }
1791                                         }
1792                                         if updated.len() > 0 {
1793                                                 htlc_updated.append(&mut updated);
1794                                         }
1795                                 } else {
1796                                         if let Some(&(commitment_number, _)) = self.remote_commitment_txn_on_chain.get(&prevout.txid) {
1797                                                 let (tx, spendable_output) = self.check_spend_remote_htlc(tx, commitment_number, fee_estimator);
1798                                                 if let Some(tx) = tx {
1799                                                         txn.push(tx);
1800                                                 }
1801                                                 if let Some(spendable_output) = spendable_output {
1802                                                         spendable_outputs.push(spendable_output);
1803                                                 }
1804                                         }
1805                                 }
1806                                 for tx in txn.iter() {
1807                                         broadcaster.broadcast_transaction(tx);
1808                                 }
1809                         }
1810                         // While all commitment/HTLC-Success/HTLC-Timeout transactions have one input, HTLCs
1811                         // can also be resolved in a few other ways which can have more than one output. Thus,
1812                         // we call is_resolving_htlc_output here outside of the tx.input.len() == 1 check.
1813                         let mut updated = self.is_resolving_htlc_output(tx);
1814                         if updated.len() > 0 {
1815                                 htlc_updated.append(&mut updated);
1816                         }
1817                 }
1818                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1819                         if self.would_broadcast_at_height(height) {
1820                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
1821                                 match self.key_storage {
1822                                         Storage::Local { ref delayed_payment_base_key, ref latest_per_commitment_point, .. } => {
1823                                                 let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, latest_per_commitment_point, &Some(*delayed_payment_base_key));
1824                                                 spendable_outputs.append(&mut spendable_output);
1825                                                 if !new_outputs.is_empty() {
1826                                                         watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
1827                                                 }
1828                                                 for tx in txs {
1829                                                         broadcaster.broadcast_transaction(&tx);
1830                                                 }
1831                                         },
1832                                         Storage::Watchtower { .. } => {
1833                                                 let (txs, mut spendable_output, new_outputs) = self.broadcast_by_local_state(&cur_local_tx, &None, &None);
1834                                                 spendable_outputs.append(&mut spendable_output);
1835                                                 if !new_outputs.is_empty() {
1836                                                         watch_outputs.push((cur_local_tx.txid.clone(), new_outputs));
1837                                                 }
1838                                                 for tx in txs {
1839                                                         broadcaster.broadcast_transaction(&tx);
1840                                                 }
1841                                         }
1842                                 }
1843                         }
1844                 }
1845                 self.last_block_hash = block_hash.clone();
1846                 (watch_outputs, spendable_outputs, htlc_updated)
1847         }
1848
1849         pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
1850                 // We need to consider all HTLCs which are:
1851                 //  * in any unrevoked remote commitment transaction, as they could broadcast said
1852                 //    transactions and we'd end up in a race, or
1853                 //  * are in our latest local commitment transaction, as this is the thing we will
1854                 //    broadcast if we go on-chain.
1855                 // Note that we consider HTLCs which were below dust threshold here - while they don't
1856                 // strictly imply that we need to fail the channel, we need to go ahead and fail them back
1857                 // to the source, and if we don't fail the channel we will have to ensure that the next
1858                 // updates that peer sends us are update_fails, failing the channel if not. It's probably
1859                 // easier to just fail the channel as this case should be rare enough anyway.
1860                 macro_rules! scan_commitment {
1861                         ($htlcs: expr, $local_tx: expr) => {
1862                                 for ref htlc in $htlcs {
1863                                         // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
1864                                         // chain with enough room to claim the HTLC without our counterparty being able to
1865                                         // time out the HTLC first.
1866                                         // For outbound HTLCs which our counterparty hasn't failed/claimed, our primary
1867                                         // concern is being able to claim the corresponding inbound HTLC (on another
1868                                         // channel) before it expires. In fact, we don't even really care if our
1869                                         // counterparty here claims such an outbound HTLC after it expired as long as we
1870                                         // can still claim the corresponding HTLC. Thus, to avoid needlessly hitting the
1871                                         // chain when our counterparty is waiting for expiration to off-chain fail an HTLC
1872                                         // we give ourselves a few blocks of headroom after expiration before going
1873                                         // on-chain for an expired HTLC.
1874                                         // Note that, to avoid a potential attack whereby a node delays claiming an HTLC
1875                                         // from us until we've reached the point where we go on-chain with the
1876                                         // corresponding inbound HTLC, we must ensure that outbound HTLCs go on chain at
1877                                         // least CLTV_CLAIM_BUFFER blocks prior to the inbound HTLC.
1878                                         //  aka outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS == height - CLTV_CLAIM_BUFFER
1879                                         //      inbound_cltv == height + CLTV_CLAIM_BUFFER
1880                                         //      outbound_cltv + HTLC_FAIL_TIMEOUT_BLOCKS + CLTV_CLAIM_BUFFER <= inbound_cltv - CLTV_CLAIM_BUFFER
1881                                         //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= inbound_cltv - outbound_cltv
1882                                         //      CLTV_EXPIRY_DELTA <= inbound_cltv - outbound_cltv (by check in ChannelManager::decode_update_add_htlc_onion)
1883                                         //      HTLC_FAIL_TIMEOUT_BLOCKS + 2*CLTV_CLAIM_BUFFER <= CLTV_EXPIRY_DELTA
1884                                         //  The final, above, condition is checked for statically in channelmanager
1885                                         //  with CHECK_CLTV_EXPIRY_SANITY_2.
1886                                         let htlc_outbound = $local_tx == htlc.offered;
1887                                         if ( htlc_outbound && htlc.cltv_expiry + HTLC_FAIL_TIMEOUT_BLOCKS <= height) ||
1888                                            (!htlc_outbound && htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER && self.payment_preimages.contains_key(&htlc.payment_hash)) {
1889                                                 log_info!(self, "Force-closing channel due to {} HTLC timeout, HTLC expiry is {}", if htlc_outbound { "outbound" } else { "inbound "}, htlc.cltv_expiry);
1890                                                 return true;
1891                                         }
1892                                 }
1893                         }
1894                 }
1895
1896                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
1897                         scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
1898                 }
1899
1900                 if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
1901                         if let &Some(ref txid) = current_remote_commitment_txid {
1902                                 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
1903                                         scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1904                                 }
1905                         }
1906                         if let &Some(ref txid) = prev_remote_commitment_txid {
1907                                 if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
1908                                         scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
1909                                 }
1910                         }
1911                 }
1912
1913                 false
1914         }
1915
1916         /// Check if any transaction broadcasted is resolving HTLC output by a success or timeout on a local
1917         /// or remote commitment tx, if so send back the source, preimage if found and payment_hash of resolved HTLC
1918         fn is_resolving_htlc_output(&mut self, tx: &Transaction) -> Vec<(HTLCSource, Option<PaymentPreimage>, PaymentHash)> {
1919                 let mut htlc_updated = Vec::new();
1920
1921                 'outer_loop: for input in &tx.input {
1922                         let mut payment_data = None;
1923                         let revocation_sig_claim = (input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33)
1924                                 || (input.witness.len() == 3 && input.witness[2].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT && input.witness[1].len() == 33);
1925                         let accepted_preimage_claim = input.witness.len() == 5 && input.witness[4].len() == ACCEPTED_HTLC_SCRIPT_WEIGHT;
1926                         let offered_preimage_claim = input.witness.len() == 3 && input.witness[2].len() == OFFERED_HTLC_SCRIPT_WEIGHT;
1927
1928                         macro_rules! log_claim {
1929                                 ($tx_info: expr, $local_tx: expr, $htlc: expr, $source_avail: expr) => {
1930                                         // We found the output in question, but aren't failing it backwards
1931                                         // as we have no corresponding source and no valid remote commitment txid
1932                                         // to try a weak source binding with same-hash, same-value still-valid offered HTLC.
1933                                         // This implies either it is an inbound HTLC or an outbound HTLC on a revoked transaction.
1934                                         let outbound_htlc = $local_tx == $htlc.offered;
1935                                         if ($local_tx && revocation_sig_claim) ||
1936                                                         (outbound_htlc && !$source_avail && (accepted_preimage_claim || offered_preimage_claim)) {
1937                                                 log_error!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}!",
1938                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
1939                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
1940                                                         if revocation_sig_claim { "revocation sig" } else { "preimage claim after we'd passed the HTLC resolution back" });
1941                                         } else {
1942                                                 log_info!(self, "Input spending {} ({}:{}) in {} resolves {} HTLC with payment hash {} with {}",
1943                                                         $tx_info, input.previous_output.txid, input.previous_output.vout, tx.txid(),
1944                                                         if outbound_htlc { "outbound" } else { "inbound" }, log_bytes!($htlc.payment_hash.0),
1945                                                         if revocation_sig_claim { "revocation sig" } else if accepted_preimage_claim || offered_preimage_claim { "preimage" } else { "timeout" });
1946                                         }
1947                                 }
1948                         }
1949
1950                         macro_rules! check_htlc_valid_remote {
1951                                 ($remote_txid: expr, $htlc_output: expr) => {
1952                                         if let &Some(txid) = $remote_txid {
1953                                                 for &(ref pending_htlc, ref pending_source) in self.remote_claimable_outpoints.get(&txid).unwrap() {
1954                                                         if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
1955                                                                 if let &Some(ref source) = pending_source {
1956                                                                         log_claim!("revoked remote commitment tx", false, pending_htlc, true);
1957                                                                         payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
1958                                                                         break;
1959                                                                 }
1960                                                         }
1961                                                 }
1962                                         }
1963                                 }
1964                         }
1965
1966                         macro_rules! scan_commitment {
1967                                 ($htlcs: expr, $tx_info: expr, $local_tx: expr) => {
1968                                         for (ref htlc_output, source_option) in $htlcs {
1969                                                 if Some(input.previous_output.vout) == htlc_output.transaction_output_index {
1970                                                         if let Some(ref source) = source_option {
1971                                                                 log_claim!($tx_info, $local_tx, htlc_output, true);
1972                                                                 // We have a resolution of an HTLC either from one of our latest
1973                                                                 // local commitment transactions or an unrevoked remote commitment
1974                                                                 // transaction. This implies we either learned a preimage, the HTLC
1975                                                                 // has timed out, or we screwed up. In any case, we should now
1976                                                                 // resolve the source HTLC with the original sender.
1977                                                                 payment_data = Some(((*source).clone(), htlc_output.payment_hash));
1978                                                         } else if !$local_tx {
1979                                                                 if let Storage::Local { ref current_remote_commitment_txid, .. } = self.key_storage {
1980                                                                         check_htlc_valid_remote!(current_remote_commitment_txid, htlc_output);
1981                                                                 }
1982                                                                 if payment_data.is_none() {
1983                                                                         if let Storage::Local { ref prev_remote_commitment_txid, .. } = self.key_storage {
1984                                                                                 check_htlc_valid_remote!(prev_remote_commitment_txid, htlc_output);
1985                                                                         }
1986                                                                 }
1987                                                         }
1988                                                         if payment_data.is_none() {
1989                                                                 log_claim!($tx_info, $local_tx, htlc_output, false);
1990                                                                 continue 'outer_loop;
1991                                                         }
1992                                                 }
1993                                         }
1994                                 }
1995                         }
1996
1997                         if let Some(ref current_local_signed_commitment_tx) = self.current_local_signed_commitment_tx {
1998                                 if input.previous_output.txid == current_local_signed_commitment_tx.txid {
1999                                         scan_commitment!(current_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2000                                                 "our latest local commitment tx", true);
2001                                 }
2002                         }
2003                         if let Some(ref prev_local_signed_commitment_tx) = self.prev_local_signed_commitment_tx {
2004                                 if input.previous_output.txid == prev_local_signed_commitment_tx.txid {
2005                                         scan_commitment!(prev_local_signed_commitment_tx.htlc_outputs.iter().map(|&(ref a, _, ref b)| (a, b.as_ref())),
2006                                                 "our previous local commitment tx", true);
2007                                 }
2008                         }
2009                         if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(&input.previous_output.txid) {
2010                                 scan_commitment!(htlc_outputs.iter().map(|&(ref a, ref b)| (a, (b.as_ref().clone()).map(|boxed| &**boxed))),
2011                                         "remote commitment tx", false);
2012                         }
2013
2014                         // Check that scan_commitment, above, decided there is some source worth relaying an
2015                         // HTLC resolution backwards to and figure out whether we learned a preimage from it.
2016                         if let Some((source, payment_hash)) = payment_data {
2017                                 let mut payment_preimage = PaymentPreimage([0; 32]);
2018                                 if accepted_preimage_claim {
2019                                         payment_preimage.0.copy_from_slice(&input.witness[3]);
2020                                         htlc_updated.push((source, Some(payment_preimage), payment_hash));
2021                                 } else if offered_preimage_claim {
2022                                         payment_preimage.0.copy_from_slice(&input.witness[1]);
2023                                         htlc_updated.push((source, Some(payment_preimage), payment_hash));
2024                                 } else {
2025                                         htlc_updated.push((source, None, payment_hash));
2026                                 }
2027                         }
2028                 }
2029                 htlc_updated
2030         }
2031 }
2032
2033 const MAX_ALLOC_SIZE: usize = 64*1024;
2034
2035 impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelMonitor) {
2036         fn read(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
2037                 let secp_ctx = Secp256k1::new();
2038                 macro_rules! unwrap_obj {
2039                         ($key: expr) => {
2040                                 match $key {
2041                                         Ok(res) => res,
2042                                         Err(_) => return Err(DecodeError::InvalidValue),
2043                                 }
2044                         }
2045                 }
2046
2047                 let _ver: u8 = Readable::read(reader)?;
2048                 let min_ver: u8 = Readable::read(reader)?;
2049                 if min_ver > SERIALIZATION_VERSION {
2050                         return Err(DecodeError::UnknownVersion);
2051                 }
2052
2053                 let commitment_transaction_number_obscure_factor = <U48 as Readable<R>>::read(reader)?.0;
2054
2055                 let key_storage = match <u8 as Readable<R>>::read(reader)? {
2056                         0 => {
2057                                 let revocation_base_key = Readable::read(reader)?;
2058                                 let htlc_base_key = Readable::read(reader)?;
2059                                 let delayed_payment_base_key = Readable::read(reader)?;
2060                                 let payment_base_key = Readable::read(reader)?;
2061                                 let shutdown_pubkey = Readable::read(reader)?;
2062                                 let prev_latest_per_commitment_point = Readable::read(reader)?;
2063                                 let latest_per_commitment_point = Readable::read(reader)?;
2064                                 // Technically this can fail and serialize fail a round-trip, but only for serialization of
2065                                 // barely-init'd ChannelMonitors that we can't do anything with.
2066                                 let outpoint = OutPoint {
2067                                         txid: Readable::read(reader)?,
2068                                         index: Readable::read(reader)?,
2069                                 };
2070                                 let funding_info = Some((outpoint, Readable::read(reader)?));
2071                                 let current_remote_commitment_txid = Readable::read(reader)?;
2072                                 let prev_remote_commitment_txid = Readable::read(reader)?;
2073                                 Storage::Local {
2074                                         revocation_base_key,
2075                                         htlc_base_key,
2076                                         delayed_payment_base_key,
2077                                         payment_base_key,
2078                                         shutdown_pubkey,
2079                                         prev_latest_per_commitment_point,
2080                                         latest_per_commitment_point,
2081                                         funding_info,
2082                                         current_remote_commitment_txid,
2083                                         prev_remote_commitment_txid,
2084                                 }
2085                         },
2086                         _ => return Err(DecodeError::InvalidValue),
2087                 };
2088
2089                 let their_htlc_base_key = Some(Readable::read(reader)?);
2090                 let their_delayed_payment_base_key = Some(Readable::read(reader)?);
2091
2092                 let their_cur_revocation_points = {
2093                         let first_idx = <U48 as Readable<R>>::read(reader)?.0;
2094                         if first_idx == 0 {
2095                                 None
2096                         } else {
2097                                 let first_point = Readable::read(reader)?;
2098                                 let second_point_slice: [u8; 33] = Readable::read(reader)?;
2099                                 if second_point_slice[0..32] == [0; 32] && second_point_slice[32] == 0 {
2100                                         Some((first_idx, first_point, None))
2101                                 } else {
2102                                         Some((first_idx, first_point, Some(unwrap_obj!(PublicKey::from_slice(&second_point_slice)))))
2103                                 }
2104                         }
2105                 };
2106
2107                 let our_to_self_delay: u16 = Readable::read(reader)?;
2108                 let their_to_self_delay: Option<u16> = Some(Readable::read(reader)?);
2109
2110                 let mut old_secrets = [([0; 32], 1 << 48); 49];
2111                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
2112                         *secret = Readable::read(reader)?;
2113                         *idx = Readable::read(reader)?;
2114                 }
2115
2116                 macro_rules! read_htlc_in_commitment {
2117                         () => {
2118                                 {
2119                                         let offered: bool = Readable::read(reader)?;
2120                                         let amount_msat: u64 = Readable::read(reader)?;
2121                                         let cltv_expiry: u32 = Readable::read(reader)?;
2122                                         let payment_hash: PaymentHash = Readable::read(reader)?;
2123                                         let transaction_output_index: Option<u32> = Readable::read(reader)?;
2124
2125                                         HTLCOutputInCommitment {
2126                                                 offered, amount_msat, cltv_expiry, payment_hash, transaction_output_index
2127                                         }
2128                                 }
2129                         }
2130                 }
2131
2132                 let remote_claimable_outpoints_len: u64 = Readable::read(reader)?;
2133                 let mut remote_claimable_outpoints = HashMap::with_capacity(cmp::min(remote_claimable_outpoints_len as usize, MAX_ALLOC_SIZE / 64));
2134                 for _ in 0..remote_claimable_outpoints_len {
2135                         let txid: Sha256dHash = Readable::read(reader)?;
2136                         let htlcs_count: u64 = Readable::read(reader)?;
2137                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
2138                         for _ in 0..htlcs_count {
2139                                 htlcs.push((read_htlc_in_commitment!(), <Option<HTLCSource> as Readable<R>>::read(reader)?.map(|o: HTLCSource| Box::new(o))));
2140                         }
2141                         if let Some(_) = remote_claimable_outpoints.insert(txid, htlcs) {
2142                                 return Err(DecodeError::InvalidValue);
2143                         }
2144                 }
2145
2146                 let remote_commitment_txn_on_chain_len: u64 = Readable::read(reader)?;
2147                 let mut remote_commitment_txn_on_chain = HashMap::with_capacity(cmp::min(remote_commitment_txn_on_chain_len as usize, MAX_ALLOC_SIZE / 32));
2148                 for _ in 0..remote_commitment_txn_on_chain_len {
2149                         let txid: Sha256dHash = Readable::read(reader)?;
2150                         let commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2151                         let outputs_count = <u64 as Readable<R>>::read(reader)?;
2152                         let mut outputs = Vec::with_capacity(cmp::min(outputs_count as usize, MAX_ALLOC_SIZE / 8));
2153                         for _ in 0..outputs_count {
2154                                 outputs.push(Readable::read(reader)?);
2155                         }
2156                         if let Some(_) = remote_commitment_txn_on_chain.insert(txid, (commitment_number, outputs)) {
2157                                 return Err(DecodeError::InvalidValue);
2158                         }
2159                 }
2160
2161                 let remote_hash_commitment_number_len: u64 = Readable::read(reader)?;
2162                 let mut remote_hash_commitment_number = HashMap::with_capacity(cmp::min(remote_hash_commitment_number_len as usize, MAX_ALLOC_SIZE / 32));
2163                 for _ in 0..remote_hash_commitment_number_len {
2164                         let payment_hash: PaymentHash = Readable::read(reader)?;
2165                         let commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2166                         if let Some(_) = remote_hash_commitment_number.insert(payment_hash, commitment_number) {
2167                                 return Err(DecodeError::InvalidValue);
2168                         }
2169                 }
2170
2171                 macro_rules! read_local_tx {
2172                         () => {
2173                                 {
2174                                         let tx = match Transaction::consensus_decode(reader.by_ref()) {
2175                                                 Ok(tx) => tx,
2176                                                 Err(e) => match e {
2177                                                         encode::Error::Io(ioe) => return Err(DecodeError::Io(ioe)),
2178                                                         _ => return Err(DecodeError::InvalidValue),
2179                                                 },
2180                                         };
2181
2182                                         if tx.input.is_empty() {
2183                                                 // Ensure tx didn't hit the 0-input ambiguity case.
2184                                                 return Err(DecodeError::InvalidValue);
2185                                         }
2186
2187                                         let revocation_key = Readable::read(reader)?;
2188                                         let a_htlc_key = Readable::read(reader)?;
2189                                         let b_htlc_key = Readable::read(reader)?;
2190                                         let delayed_payment_key = Readable::read(reader)?;
2191                                         let feerate_per_kw: u64 = Readable::read(reader)?;
2192
2193                                         let htlcs_len: u64 = Readable::read(reader)?;
2194                                         let mut htlcs = Vec::with_capacity(cmp::min(htlcs_len as usize, MAX_ALLOC_SIZE / 128));
2195                                         for _ in 0..htlcs_len {
2196                                                 let htlc = read_htlc_in_commitment!();
2197                                                 let sigs = match <u8 as Readable<R>>::read(reader)? {
2198                                                         0 => None,
2199                                                         1 => Some((Readable::read(reader)?, Readable::read(reader)?)),
2200                                                         _ => return Err(DecodeError::InvalidValue),
2201                                                 };
2202                                                 htlcs.push((htlc, sigs, Readable::read(reader)?));
2203                                         }
2204
2205                                         LocalSignedTx {
2206                                                 txid: tx.txid(),
2207                                                 tx, revocation_key, a_htlc_key, b_htlc_key, delayed_payment_key, feerate_per_kw,
2208                                                 htlc_outputs: htlcs
2209                                         }
2210                                 }
2211                         }
2212                 }
2213
2214                 let prev_local_signed_commitment_tx = match <u8 as Readable<R>>::read(reader)? {
2215                         0 => None,
2216                         1 => {
2217                                 Some(read_local_tx!())
2218                         },
2219                         _ => return Err(DecodeError::InvalidValue),
2220                 };
2221
2222                 let current_local_signed_commitment_tx = match <u8 as Readable<R>>::read(reader)? {
2223                         0 => None,
2224                         1 => {
2225                                 Some(read_local_tx!())
2226                         },
2227                         _ => return Err(DecodeError::InvalidValue),
2228                 };
2229
2230                 let current_remote_commitment_number = <U48 as Readable<R>>::read(reader)?.0;
2231
2232                 let payment_preimages_len: u64 = Readable::read(reader)?;
2233                 let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
2234                 for _ in 0..payment_preimages_len {
2235                         let preimage: PaymentPreimage = Readable::read(reader)?;
2236                         let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2237                         if let Some(_) = payment_preimages.insert(hash, preimage) {
2238                                 return Err(DecodeError::InvalidValue);
2239                         }
2240                 }
2241
2242                 let last_block_hash: Sha256dHash = Readable::read(reader)?;
2243                 let destination_script = Readable::read(reader)?;
2244
2245                 Ok((last_block_hash.clone(), ChannelMonitor {
2246                         commitment_transaction_number_obscure_factor,
2247
2248                         key_storage,
2249                         their_htlc_base_key,
2250                         their_delayed_payment_base_key,
2251                         their_cur_revocation_points,
2252
2253                         our_to_self_delay,
2254                         their_to_self_delay,
2255
2256                         old_secrets,
2257                         remote_claimable_outpoints,
2258                         remote_commitment_txn_on_chain,
2259                         remote_hash_commitment_number,
2260
2261                         prev_local_signed_commitment_tx,
2262                         current_local_signed_commitment_tx,
2263                         current_remote_commitment_number,
2264
2265                         payment_preimages,
2266
2267                         destination_script,
2268                         last_block_hash,
2269                         secp_ctx,
2270                         logger,
2271                 }))
2272         }
2273
2274 }
2275
2276 #[cfg(test)]
2277 mod tests {
2278         use bitcoin::blockdata::script::{Script, Builder};
2279         use bitcoin::blockdata::opcodes;
2280         use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
2281         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
2282         use bitcoin::util::bip143;
2283         use bitcoin_hashes::Hash;
2284         use bitcoin_hashes::sha256::Hash as Sha256;
2285         use bitcoin_hashes::sha256d::Hash as Sha256dHash;
2286         use bitcoin_hashes::hex::FromHex;
2287         use hex;
2288         use ln::channelmanager::{PaymentPreimage, PaymentHash};
2289         use ln::channelmonitor::{ChannelMonitor, InputDescriptors};
2290         use ln::chan_utils;
2291         use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
2292         use util::test_utils::TestLogger;
2293         use secp256k1::key::{SecretKey,PublicKey};
2294         use secp256k1::Secp256k1;
2295         use rand::{thread_rng,Rng};
2296         use std::sync::Arc;
2297
2298         #[test]
2299         fn test_per_commitment_storage() {
2300                 // Test vectors from BOLT 3:
2301                 let mut secrets: Vec<[u8; 32]> = Vec::new();
2302                 let mut monitor: ChannelMonitor;
2303                 let secp_ctx = Secp256k1::new();
2304                 let logger = Arc::new(TestLogger::new());
2305
2306                 macro_rules! test_secrets {
2307                         () => {
2308                                 let mut idx = 281474976710655;
2309                                 for secret in secrets.iter() {
2310                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
2311                                         idx -= 1;
2312                                 }
2313                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
2314                                 assert!(monitor.get_secret(idx).is_none());
2315                         };
2316                 }
2317
2318                 {
2319                         // insert_secret correct sequence
2320                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2321                         secrets.clear();
2322
2323                         secrets.push([0; 32]);
2324                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2325                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2326                         test_secrets!();
2327
2328                         secrets.push([0; 32]);
2329                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2330                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2331                         test_secrets!();
2332
2333                         secrets.push([0; 32]);
2334                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2335                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2336                         test_secrets!();
2337
2338                         secrets.push([0; 32]);
2339                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2340                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2341                         test_secrets!();
2342
2343                         secrets.push([0; 32]);
2344                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2345                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2346                         test_secrets!();
2347
2348                         secrets.push([0; 32]);
2349                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2350                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2351                         test_secrets!();
2352
2353                         secrets.push([0; 32]);
2354                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2355                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2356                         test_secrets!();
2357
2358                         secrets.push([0; 32]);
2359                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2360                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
2361                         test_secrets!();
2362                 }
2363
2364                 {
2365                         // insert_secret #1 incorrect
2366                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2367                         secrets.clear();
2368
2369                         secrets.push([0; 32]);
2370                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2371                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2372                         test_secrets!();
2373
2374                         secrets.push([0; 32]);
2375                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2376                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap_err().0,
2377                                         "Previous secret did not match new one");
2378                 }
2379
2380                 {
2381                         // insert_secret #2 incorrect (#1 derived from incorrect)
2382                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2383                         secrets.clear();
2384
2385                         secrets.push([0; 32]);
2386                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2387                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2388                         test_secrets!();
2389
2390                         secrets.push([0; 32]);
2391                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2392                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2393                         test_secrets!();
2394
2395                         secrets.push([0; 32]);
2396                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2397                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2398                         test_secrets!();
2399
2400                         secrets.push([0; 32]);
2401                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2402                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
2403                                         "Previous secret did not match new one");
2404                 }
2405
2406                 {
2407                         // insert_secret #3 incorrect
2408                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2409                         secrets.clear();
2410
2411                         secrets.push([0; 32]);
2412                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2413                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2414                         test_secrets!();
2415
2416                         secrets.push([0; 32]);
2417                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2418                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2419                         test_secrets!();
2420
2421                         secrets.push([0; 32]);
2422                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2423                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2424                         test_secrets!();
2425
2426                         secrets.push([0; 32]);
2427                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2428                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap_err().0,
2429                                         "Previous secret did not match new one");
2430                 }
2431
2432                 {
2433                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
2434                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2435                         secrets.clear();
2436
2437                         secrets.push([0; 32]);
2438                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2439                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2440                         test_secrets!();
2441
2442                         secrets.push([0; 32]);
2443                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2444                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2445                         test_secrets!();
2446
2447                         secrets.push([0; 32]);
2448                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2449                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2450                         test_secrets!();
2451
2452                         secrets.push([0; 32]);
2453                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
2454                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2455                         test_secrets!();
2456
2457                         secrets.push([0; 32]);
2458                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2459                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2460                         test_secrets!();
2461
2462                         secrets.push([0; 32]);
2463                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2464                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2465                         test_secrets!();
2466
2467                         secrets.push([0; 32]);
2468                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2469                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2470                         test_secrets!();
2471
2472                         secrets.push([0; 32]);
2473                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2474                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2475                                         "Previous secret did not match new one");
2476                 }
2477
2478                 {
2479                         // insert_secret #5 incorrect
2480                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2481                         secrets.clear();
2482
2483                         secrets.push([0; 32]);
2484                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2485                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2486                         test_secrets!();
2487
2488                         secrets.push([0; 32]);
2489                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2490                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2491                         test_secrets!();
2492
2493                         secrets.push([0; 32]);
2494                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2495                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2496                         test_secrets!();
2497
2498                         secrets.push([0; 32]);
2499                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2500                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2501                         test_secrets!();
2502
2503                         secrets.push([0; 32]);
2504                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2505                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2506                         test_secrets!();
2507
2508                         secrets.push([0; 32]);
2509                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2510                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap_err().0,
2511                                         "Previous secret did not match new one");
2512                 }
2513
2514                 {
2515                         // insert_secret #6 incorrect (5 derived from incorrect)
2516                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2517                         secrets.clear();
2518
2519                         secrets.push([0; 32]);
2520                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2521                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2522                         test_secrets!();
2523
2524                         secrets.push([0; 32]);
2525                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2526                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2527                         test_secrets!();
2528
2529                         secrets.push([0; 32]);
2530                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2531                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2532                         test_secrets!();
2533
2534                         secrets.push([0; 32]);
2535                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2536                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2537                         test_secrets!();
2538
2539                         secrets.push([0; 32]);
2540                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2541                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2542                         test_secrets!();
2543
2544                         secrets.push([0; 32]);
2545                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
2546                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2547                         test_secrets!();
2548
2549                         secrets.push([0; 32]);
2550                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2551                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2552                         test_secrets!();
2553
2554                         secrets.push([0; 32]);
2555                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2556                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2557                                         "Previous secret did not match new one");
2558                 }
2559
2560                 {
2561                         // insert_secret #7 incorrect
2562                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2563                         secrets.clear();
2564
2565                         secrets.push([0; 32]);
2566                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2567                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2568                         test_secrets!();
2569
2570                         secrets.push([0; 32]);
2571                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2572                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2573                         test_secrets!();
2574
2575                         secrets.push([0; 32]);
2576                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2577                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2578                         test_secrets!();
2579
2580                         secrets.push([0; 32]);
2581                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2582                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2583                         test_secrets!();
2584
2585                         secrets.push([0; 32]);
2586                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2587                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2588                         test_secrets!();
2589
2590                         secrets.push([0; 32]);
2591                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2592                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2593                         test_secrets!();
2594
2595                         secrets.push([0; 32]);
2596                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
2597                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2598                         test_secrets!();
2599
2600                         secrets.push([0; 32]);
2601                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2602                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2603                                         "Previous secret did not match new one");
2604                 }
2605
2606                 {
2607                         // insert_secret #8 incorrect
2608                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2609                         secrets.clear();
2610
2611                         secrets.push([0; 32]);
2612                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2613                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2614                         test_secrets!();
2615
2616                         secrets.push([0; 32]);
2617                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2618                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2619                         test_secrets!();
2620
2621                         secrets.push([0; 32]);
2622                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2623                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2624                         test_secrets!();
2625
2626                         secrets.push([0; 32]);
2627                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2628                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2629                         test_secrets!();
2630
2631                         secrets.push([0; 32]);
2632                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2633                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2634                         test_secrets!();
2635
2636                         secrets.push([0; 32]);
2637                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2638                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2639                         test_secrets!();
2640
2641                         secrets.push([0; 32]);
2642                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2643                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2644                         test_secrets!();
2645
2646                         secrets.push([0; 32]);
2647                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
2648                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap_err().0,
2649                                         "Previous secret did not match new one");
2650                 }
2651         }
2652
2653         #[test]
2654         fn test_prune_preimages() {
2655                 let secp_ctx = Secp256k1::new();
2656                 let logger = Arc::new(TestLogger::new());
2657
2658                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2659                 macro_rules! dummy_keys {
2660                         () => {
2661                                 {
2662                                         TxCreationKeys {
2663                                                 per_commitment_point: dummy_key.clone(),
2664                                                 revocation_key: dummy_key.clone(),
2665                                                 a_htlc_key: dummy_key.clone(),
2666                                                 b_htlc_key: dummy_key.clone(),
2667                                                 a_delayed_payment_key: dummy_key.clone(),
2668                                                 b_payment_key: dummy_key.clone(),
2669                                         }
2670                                 }
2671                         }
2672                 }
2673                 let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2674
2675                 let mut preimages = Vec::new();
2676                 {
2677                         let mut rng  = thread_rng();
2678                         for _ in 0..20 {
2679                                 let mut preimage = PaymentPreimage([0; 32]);
2680                                 rng.fill_bytes(&mut preimage.0[..]);
2681                                 let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
2682                                 preimages.push((preimage, hash));
2683                         }
2684                 }
2685
2686                 macro_rules! preimages_slice_to_htlc_outputs {
2687                         ($preimages_slice: expr) => {
2688                                 {
2689                                         let mut res = Vec::new();
2690                                         for (idx, preimage) in $preimages_slice.iter().enumerate() {
2691                                                 res.push((HTLCOutputInCommitment {
2692                                                         offered: true,
2693                                                         amount_msat: 0,
2694                                                         cltv_expiry: 0,
2695                                                         payment_hash: preimage.1.clone(),
2696                                                         transaction_output_index: Some(idx as u32),
2697                                                 }, None));
2698                                         }
2699                                         res
2700                                 }
2701                         }
2702                 }
2703                 macro_rules! preimages_to_local_htlcs {
2704                         ($preimages_slice: expr) => {
2705                                 {
2706                                         let mut inp = preimages_slice_to_htlc_outputs!($preimages_slice);
2707                                         let res: Vec<_> = inp.drain(..).map(|e| { (e.0, None, e.1) }).collect();
2708                                         res
2709                                 }
2710                         }
2711                 }
2712
2713                 macro_rules! test_preimages_exist {
2714                         ($preimages_slice: expr, $monitor: expr) => {
2715                                 for preimage in $preimages_slice {
2716                                         assert!($monitor.payment_preimages.contains_key(&preimage.1));
2717                                 }
2718                         }
2719                 }
2720
2721                 // Prune with one old state and a local commitment tx holding a few overlaps with the
2722                 // old state.
2723                 let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[43; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &SecretKey::from_slice(&[44; 32]).unwrap(), &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[45; 32]).unwrap()), 0, Script::new(), logger.clone());
2724                 monitor.set_their_to_self_delay(10);
2725
2726                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..10]));
2727                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key);
2728                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[15..20]), 281474976710654, dummy_key);
2729                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[17..20]), 281474976710653, dummy_key);
2730                 monitor.provide_latest_remote_commitment_tx_info(&dummy_tx, preimages_slice_to_htlc_outputs!(preimages[18..20]), 281474976710652, dummy_key);
2731                 for &(ref preimage, ref hash) in preimages.iter() {
2732                         monitor.provide_payment_preimage(hash, preimage);
2733                 }
2734
2735                 // Now provide a secret, pruning preimages 10-15
2736                 let mut secret = [0; 32];
2737                 secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2738                 monitor.provide_secret(281474976710655, secret.clone()).unwrap();
2739                 assert_eq!(monitor.payment_preimages.len(), 15);
2740                 test_preimages_exist!(&preimages[0..10], monitor);
2741                 test_preimages_exist!(&preimages[15..20], monitor);
2742
2743                 // Now provide a further secret, pruning preimages 15-17
2744                 secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2745                 monitor.provide_secret(281474976710654, secret.clone()).unwrap();
2746                 assert_eq!(monitor.payment_preimages.len(), 13);
2747                 test_preimages_exist!(&preimages[0..10], monitor);
2748                 test_preimages_exist!(&preimages[17..20], monitor);
2749
2750                 // Now update local commitment tx info, pruning only element 18 as we still care about the
2751                 // previous commitment tx's preimages too
2752                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..5]));
2753                 secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2754                 monitor.provide_secret(281474976710653, secret.clone()).unwrap();
2755                 assert_eq!(monitor.payment_preimages.len(), 12);
2756                 test_preimages_exist!(&preimages[0..10], monitor);
2757                 test_preimages_exist!(&preimages[18..20], monitor);
2758
2759                 // But if we do it again, we'll prune 5-10
2760                 monitor.provide_latest_local_commitment_tx_info(dummy_tx.clone(), dummy_keys!(), 0, preimages_to_local_htlcs!(preimages[0..3]));
2761                 secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2762                 monitor.provide_secret(281474976710652, secret.clone()).unwrap();
2763                 assert_eq!(monitor.payment_preimages.len(), 5);
2764                 test_preimages_exist!(&preimages[0..5], monitor);
2765         }
2766
2767         #[test]
2768         fn test_claim_txn_weight_computation() {
2769                 // We test Claim txn weight, knowing that we want expected weigth and
2770                 // not actual case to avoid sigs and time-lock delays hell variances.
2771
2772                 let secp_ctx = Secp256k1::new();
2773                 let privkey = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
2774                 let pubkey = PublicKey::from_secret_key(&secp_ctx, &privkey);
2775                 let mut sum_actual_sigs: u64 = 0;
2776
2777                 macro_rules! sign_input {
2778                         ($sighash_parts: expr, $input: expr, $idx: expr, $amount: expr, $input_type: expr, $sum_actual_sigs: expr) => {
2779                                 let htlc = HTLCOutputInCommitment {
2780                                         offered: if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::OfferedHTLC { true } else { false },
2781                                         amount_msat: 0,
2782                                         cltv_expiry: 2 << 16,
2783                                         payment_hash: PaymentHash([1; 32]),
2784                                         transaction_output_index: Some($idx),
2785                                 };
2786                                 let redeem_script = if *$input_type == InputDescriptors::RevokedOutput { chan_utils::get_revokeable_redeemscript(&pubkey, 256, &pubkey) } else { chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &pubkey, &pubkey, &pubkey) };
2787                                 let sighash = hash_to_message!(&$sighash_parts.sighash_all(&$input, &redeem_script, $amount)[..]);
2788                                 let sig = secp_ctx.sign(&sighash, &privkey);
2789                                 $input.witness.push(sig.serialize_der().to_vec());
2790                                 $input.witness[0].push(SigHashType::All as u8);
2791                                 sum_actual_sigs += $input.witness[0].len() as u64;
2792                                 if *$input_type == InputDescriptors::RevokedOutput {
2793                                         $input.witness.push(vec!(1));
2794                                 } else if *$input_type == InputDescriptors::RevokedOfferedHTLC || *$input_type == InputDescriptors::RevokedReceivedHTLC {
2795                                         $input.witness.push(pubkey.clone().serialize().to_vec());
2796                                 } else if *$input_type == InputDescriptors::ReceivedHTLC {
2797                                         $input.witness.push(vec![0]);
2798                                 } else {
2799                                         $input.witness.push(PaymentPreimage([1; 32]).0.to_vec());
2800                                 }
2801                                 $input.witness.push(redeem_script.into_bytes());
2802                                 println!("witness[0] {}", $input.witness[0].len());
2803                                 println!("witness[1] {}", $input.witness[1].len());
2804                                 println!("witness[2] {}", $input.witness[2].len());
2805                         }
2806                 }
2807
2808                 let script_pubkey = Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script();
2809                 let txid = Sha256dHash::from_hex("56944c5d3f98413ef45cf54545538103cc9f298e0575820ad3591376e2e0f65d").unwrap();
2810
2811                 // Justice tx with 1 to_local, 2 revoked offered HTLCs, 1 revoked received HTLCs
2812                 let mut claim_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
2813                 for i in 0..4 {
2814                         claim_tx.input.push(TxIn {
2815                                 previous_output: BitcoinOutPoint {
2816                                         txid,
2817                                         vout: i,
2818                                 },
2819                                 script_sig: Script::new(),
2820                                 sequence: 0xfffffffd,
2821                                 witness: Vec::new(),
2822                         });
2823                 }
2824                 claim_tx.output.push(TxOut {
2825                         script_pubkey: script_pubkey.clone(),
2826                         value: 0,
2827                 });
2828                 let base_weight = claim_tx.get_weight();
2829                 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2830                 let inputs_des = vec![InputDescriptors::RevokedOutput, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedOfferedHTLC, InputDescriptors::RevokedReceivedHTLC];
2831                 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2832                         sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2833                 }
2834                 assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
2835
2836                 // Claim tx with 1 offered HTLCs, 3 received HTLCs
2837                 claim_tx.input.clear();
2838                 sum_actual_sigs = 0;
2839                 for i in 0..4 {
2840                         claim_tx.input.push(TxIn {
2841                                 previous_output: BitcoinOutPoint {
2842                                         txid,
2843                                         vout: i,
2844                                 },
2845                                 script_sig: Script::new(),
2846                                 sequence: 0xfffffffd,
2847                                 witness: Vec::new(),
2848                         });
2849                 }
2850                 let base_weight = claim_tx.get_weight();
2851                 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2852                 let inputs_des = vec![InputDescriptors::OfferedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC, InputDescriptors::ReceivedHTLC];
2853                 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2854                         sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2855                 }
2856                 assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
2857
2858                 // Justice tx with 1 revoked HTLC-Success tx output
2859                 claim_tx.input.clear();
2860                 sum_actual_sigs = 0;
2861                 claim_tx.input.push(TxIn {
2862                         previous_output: BitcoinOutPoint {
2863                                 txid,
2864                                 vout: 0,
2865                         },
2866                         script_sig: Script::new(),
2867                         sequence: 0xfffffffd,
2868                         witness: Vec::new(),
2869                 });
2870                 let base_weight = claim_tx.get_weight();
2871                 let sighash_parts = bip143::SighashComponents::new(&claim_tx);
2872                 let inputs_des = vec![InputDescriptors::RevokedOutput];
2873                 for (idx, inp) in claim_tx.input.iter_mut().zip(inputs_des.iter()).enumerate() {
2874                         sign_input!(sighash_parts, inp.0, idx as u32, 0, inp.1, sum_actual_sigs);
2875                 }
2876                 assert_eq!(base_weight + ChannelMonitor::get_witnesses_weight(&inputs_des), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() as u64 - sum_actual_sigs));
2877         }
2878
2879         // Further testing is done in the ChannelManager integration tests.
2880 }