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

   1 use bitcoin::blockdata::block::BlockHeader;
   2 use bitcoin::blockdata::transaction::{TxIn,TxOut,SigHashType,Transaction};
   3 use bitcoin::blockdata::script::Script;
   4 use bitcoin::util::hash::Sha256dHash;
   5 use bitcoin::util::bip143;
   6
   7 use crypto::digest::Digest;
   8
   9 use secp256k1::{Secp256k1,Message,Signature};
  10 use secp256k1::key::{SecretKey,PublicKey};
  11
  12 use ln::msgs::HandleError;
  13 use ln::chan_utils;
  14 use ln::chan_utils::HTLCOutputInCommitment;
  15 use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
  16 use util::sha2::Sha256;
  17
  18 use std::collections::HashMap;
  19 use std::sync::{Arc,Mutex};
  20 use std::{hash,cmp};
  21
  22 pub enum ChannelMonitorUpdateErr {
  23         /// Used to indicate a temporary failure (eg connection to a watchtower failed, but is expected
  24         /// to succeed at some point in the future).
  25         /// Such a failure will "freeze" a channel, preventing us from revoking old states or
  26         /// submitting new commitment transactions to the remote party.
  27         /// ChannelManager::test_restore_channel_monitor can be used to retry the update(s) and restore
  28         /// the channel to an operational state.
  29         TemporaryFailure,
  30         /// Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
  31         /// different watchtower and cannot update with all watchtowers that were previously informed
  32         /// of this channel). This will force-close the channel in question.
  33         PermanentFailure,
  34 }
  35
  36 /// Simple trait indicating ability to track a set of ChannelMonitors and multiplex events between
  37 /// them. Generally should be implemented by keeping a local SimpleManyChannelMonitor and passing
  38 /// events to it, while also taking any add_update_monitor events and passing them to some remote
  39 /// server(s).
  40 /// Note that any updates to a channel's monitor *must* be applied to each instance of the
  41 /// channel's monitor everywhere (including remote watchtowers) *before* this function returns. If
  42 /// an update occurs and a remote watchtower is left with old state, it may broadcast transactions
  43 /// which we have revoked, allowing our counterparty to claim all funds in the channel!
  44 pub trait ManyChannelMonitor: Send + Sync {
  45         /// Adds or updates a monitor for the given funding_txid+funding_output_index.
  46         fn add_update_monitor(&self, funding_txo: (Sha256dHash, u16), monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr>;
  47 }
  48
  49 /// A simple implementation of a ManyChannelMonitor and ChainListener. Can be used to create a
  50 /// watchtower or watch our own channels.
  51 /// Note that you must provide your own key by which to refer to channels.
  52 /// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
  53 /// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
  54 /// index by a PublicKey which is required to sign any updates.
  55 /// If you're using this for local monitoring of your own channels, you probably want to use
  56 /// (Sha256dHash, u16) as the key, which will give you a ManyChannelMonitor implementation.
  57 pub struct SimpleManyChannelMonitor<Key> {
  58         monitors: Mutex<HashMap<Key, ChannelMonitor>>,
  59         chain_monitor: Arc<ChainWatchInterface>,
  60         broadcaster: Arc<BroadcasterInterface>
  61 }
  62
  63 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
  64         fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
  65                 let monitors = self.monitors.lock().unwrap();
  66                 for monitor in monitors.values() {
  67                         monitor.block_connected(txn_matched, height, &*self.broadcaster);
  68                 }
  69         }
  70
  71         fn block_disconnected(&self, _: &BlockHeader) { }
  72 }
  73
  74 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
  75         pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
  76                 let res = Arc::new(SimpleManyChannelMonitor {
  77                         monitors: Mutex::new(HashMap::new()),
  78                         chain_monitor,
  79                         broadcaster
  80                 });
  81                 let weak_res = Arc::downgrade(&res);
  82                 res.chain_monitor.register_listener(weak_res);
  83                 res
  84         }
  85
  86         pub fn add_update_monitor_by_key(&self, key: Key, monitor: ChannelMonitor) -> Result<(), HandleError> {
  87                 let mut monitors = self.monitors.lock().unwrap();
  88                 match monitors.get_mut(&key) {
  89                         Some(orig_monitor) => return orig_monitor.insert_combine(monitor),
  90                         None => {}
  91                 };
  92                 match monitor.funding_txo {
  93                         None => self.chain_monitor.watch_all_txn(),
  94                         Some((funding_txid, funding_output_index)) => self.chain_monitor.install_watch_outpoint((funding_txid, funding_output_index as u32)),
  95                 }
  96                 monitors.insert(key, monitor);
  97                 Ok(())
  98         }
  99 }
 100
 101 impl ManyChannelMonitor for SimpleManyChannelMonitor<(Sha256dHash, u16)> {
 102         fn add_update_monitor(&self, funding_txo: (Sha256dHash, u16), monitor: ChannelMonitor) -> Result<(), ChannelMonitorUpdateErr> {
 103                 match self.add_update_monitor_by_key(funding_txo, monitor) {
 104                         Ok(_) => Ok(()),
 105                         Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 106                 }
 107         }
 108 }
 109
 110 /// If an HTLC expires within this many blocks, don't try to claim it in a shared transaction,
 111 /// instead claiming it in its own individual transaction.
 112 const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 113 /// If an HTLC expires within this many blocks, force-close the channel to broadcast the
 114 /// HTLC-Success transaction.
 115 const CLTV_CLAIM_BUFFER: u32 = 6;
 116
 117 #[derive(Clone)]
 118 enum KeyStorage {
 119         PrivMode {
 120                 revocation_base_key: SecretKey,
 121                 htlc_base_key: SecretKey,
 122         },
 123         SigsMode {
 124                 revocation_base_key: PublicKey,
 125                 htlc_base_key: PublicKey,
 126                 sigs: HashMap<Sha256dHash, Signature>,
 127         }
 128 }
 129
 130 #[derive(Clone)]
 131 struct LocalSignedTx {
 132         txid: Sha256dHash,
 133         tx: Transaction,
 134         revocation_key: PublicKey,
 135         a_htlc_key: PublicKey,
 136         b_htlc_key: PublicKey,
 137         delayed_payment_key: PublicKey,
 138         feerate_per_kw: u64,
 139         htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>,
 140 }
 141
 142 pub struct ChannelMonitor {
 143         funding_txo: Option<(Sha256dHash, u16)>,
 144         commitment_transaction_number_obscure_factor: u64,
 145
 146         key_storage: KeyStorage,
 147         delayed_payment_base_key: PublicKey,
 148         their_htlc_base_key: Option<PublicKey>,
 149         // first is the idx of the first of the two revocation points
 150         their_cur_revocation_points: Option<(u64, PublicKey, Option<PublicKey>)>,
 151
 152         our_to_self_delay: u16,
 153         their_to_self_delay: Option<u16>,
 154
 155         old_secrets: [([u8; 32], u64); 49],
 156         remote_claimable_outpoints: HashMap<Sha256dHash, Vec<HTLCOutputInCommitment>>,
 157         remote_htlc_outputs_on_chain: Mutex<HashMap<Sha256dHash, u64>>,
 158         //hash to commitment number mapping use to determine the state of transaction owning it
 159         // (revoked/non-revoked) and so lightnen pruning
 160         remote_hash_commitment_number: HashMap<[u8; 32], u64>,
 161
 162         // We store two local commitment transactions to avoid any race conditions where we may update
 163         // some monitors (potentially on watchtowers) but then fail to update others, resulting in the
 164         // various monitors for one channel being out of sync, and us broadcasting a local
 165         // transaction for which we have deleted claim information on some watchtowers.
 166         prev_local_signed_commitment_tx: Option<LocalSignedTx>,
 167         current_local_signed_commitment_tx: Option<LocalSignedTx>,
 168
 169         payment_preimages: HashMap<[u8; 32], [u8; 32]>,
 170
 171         destination_script: Script,
 172         secp_ctx: Secp256k1, //TODO: dedup this a bit...
 173 }
 174 impl Clone for ChannelMonitor {
 175         fn clone(&self) -> Self {
 176                 ChannelMonitor {
 177                         funding_txo: self.funding_txo.clone(),
 178                         commitment_transaction_number_obscure_factor: self.commitment_transaction_number_obscure_factor.clone(),
 179
 180                         key_storage: self.key_storage.clone(),
 181                         delayed_payment_base_key: self.delayed_payment_base_key.clone(),
 182                         their_htlc_base_key: self.their_htlc_base_key.clone(),
 183                         their_cur_revocation_points: self.their_cur_revocation_points.clone(),
 184
 185                         our_to_self_delay: self.our_to_self_delay,
 186                         their_to_self_delay: self.their_to_self_delay,
 187
 188                         old_secrets: self.old_secrets.clone(),
 189                         remote_claimable_outpoints: self.remote_claimable_outpoints.clone(),
 190                         remote_htlc_outputs_on_chain: Mutex::new((*self.remote_htlc_outputs_on_chain.lock().unwrap()).clone()),
 191                         remote_hash_commitment_number: self.remote_hash_commitment_number.clone(),
 192
 193                         prev_local_signed_commitment_tx: self.prev_local_signed_commitment_tx.clone(),
 194                         current_local_signed_commitment_tx: self.current_local_signed_commitment_tx.clone(),
 195
 196                         payment_preimages: self.payment_preimages.clone(),
 197
 198                         destination_script: self.destination_script.clone(),
 199                         secp_ctx: self.secp_ctx.clone(),
 200                 }
 201         }
 202 }
 203
 204 impl ChannelMonitor {
 205         pub fn new(revocation_base_key: &SecretKey, delayed_payment_base_key: &PublicKey, htlc_base_key: &SecretKey, our_to_self_delay: u16, destination_script: Script) -> ChannelMonitor {
 206                 ChannelMonitor {
 207                         funding_txo: None,
 208                         commitment_transaction_number_obscure_factor: 0,
 209
 210                         key_storage: KeyStorage::PrivMode {
 211                                 revocation_base_key: revocation_base_key.clone(),
 212                                 htlc_base_key: htlc_base_key.clone(),
 213                         },
 214                         delayed_payment_base_key: delayed_payment_base_key.clone(),
 215                         their_htlc_base_key: None,
 216                         their_cur_revocation_points: None,
 217
 218                         our_to_self_delay: our_to_self_delay,
 219                         their_to_self_delay: None,
 220
 221                         old_secrets: [([0; 32], 1 << 48); 49],
 222                         remote_claimable_outpoints: HashMap::new(),
 223                         remote_htlc_outputs_on_chain: Mutex::new(HashMap::new()),
 224                         remote_hash_commitment_number: HashMap::new(),
 225
 226                         prev_local_signed_commitment_tx: None,
 227                         current_local_signed_commitment_tx: None,
 228
 229                         payment_preimages: HashMap::new(),
 230
 231                         destination_script: destination_script,
 232                         secp_ctx: Secp256k1::new(),
 233                 }
 234         }
 235
 236         #[inline]
 237         fn place_secret(idx: u64) -> u8 {
 238                 for i in 0..48 {
 239                         if idx & (1 << i) == (1 << i) {
 240                                 return i
 241                         }
 242                 }
 243                 48
 244         }
 245
 246         #[inline]
 247         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 248                 let mut res: [u8; 32] = secret;
 249                 for i in 0..bits {
 250                         let bitpos = bits - 1 - i;
 251                         if idx & (1 << bitpos) == (1 << bitpos) {
 252                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 253                                 let mut sha = Sha256::new();
 254                                 sha.input(&res);
 255                                 sha.result(&mut res);
 256                         }
 257                 }
 258                 res
 259         }
 260
 261         /// Inserts a revocation secret into this channel monitor. Also optionally tracks the next
 262         /// revocation point which may be required to claim HTLC outputs which we know the preimage of
 263         /// in case the remote end force-closes using their latest state. Prunes old preimages if neither
 264         /// needed by local commitment transactions HTCLs nor by remote ones. Unless we haven't already seen remote
 265         /// commitment transaction's secret, they are de facto pruned (we can use revocation key).
 266         pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32], their_next_revocation_point: Option<(u64, PublicKey)>) -> Result<(), HandleError> {
 267                 let pos = ChannelMonitor::place_secret(idx);
 268                 for i in 0..pos {
 269                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 270                         if ChannelMonitor::derive_secret(secret, pos, old_idx) != old_secret {
 271                                 return Err(HandleError{err: "Previous secret did not match new one", msg: None})
 272                         }
 273                 }
 274                 self.old_secrets[pos as usize] = (secret, idx);
 275
 276                 if let Some(new_revocation_point) = their_next_revocation_point {
 277                         match self.their_cur_revocation_points {
 278                                 Some(old_points) => {
 279                                         if old_points.0 == new_revocation_point.0 + 1 {
 280                                                 self.their_cur_revocation_points = Some((old_points.0, old_points.1, Some(new_revocation_point.1)));
 281                                         } else if old_points.0 == new_revocation_point.0 + 2 {
 282                                                 if let Some(old_second_point) = old_points.2 {
 283                                                         self.their_cur_revocation_points = Some((old_points.0 - 1, old_second_point, Some(new_revocation_point.1)));
 284                                                 } else {
 285                                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 286                                                 }
 287                                         } else {
 288                                                 self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 289                                         }
 290                                 },
 291                                 None => {
 292                                         self.their_cur_revocation_points = Some((new_revocation_point.0, new_revocation_point.1, None));
 293                                 }
 294                         }
 295                 }
 296
 297                 if !self.payment_preimages.is_empty() {
 298                         let local_signed_commitment_tx = self.current_local_signed_commitment_tx.as_ref().expect("Channel needs at least an initial commitment tx !");
 299                         let prev_local_signed_commitment_tx = self.prev_local_signed_commitment_tx.as_ref();
 300                         let min_idx = self.get_min_seen_secret();
 301                         let remote_hash_commitment_number = &mut self.remote_hash_commitment_number;
 302
 303                         self.payment_preimages.retain(|&k, _| {
 304                                 for &(ref htlc, _, _) in &local_signed_commitment_tx.htlc_outputs {
 305                                         if k == htlc.payment_hash {
 306                                                 return true
 307                                         }
 308                                 }
 309                                 if let Some(prev_local_commitment_tx) = prev_local_signed_commitment_tx {
 310                                         for &(ref htlc, _, _) in prev_local_commitment_tx.htlc_outputs.iter() {
 311                                                 if k == htlc.payment_hash {
 312                                                         return true
 313                                                 }
 314                                         }
 315                                 }
 316                                 let contains = if let Some(cn) = remote_hash_commitment_number.get(&k) {
 317                                         if *cn < min_idx {
 318                                                 return true
 319                                         }
 320                                         true
 321                                 } else { false };
 322                                 if contains {
 323                                         remote_hash_commitment_number.remove(&k);
 324                                 }
 325                                 false
 326                         });
 327                 }
 328
 329                 Ok(())
 330         }
 331
 332         /// Informs this monitor of the latest remote (ie non-broadcastable) commitment transaction.
 333         /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
 334         /// possibly future revocation/preimage information) to claim outputs where possible.
 335         /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
 336         pub fn provide_latest_remote_commitment_tx_info(&mut self, unsigned_commitment_tx: &Transaction, htlc_outputs: Vec<HTLCOutputInCommitment>, commitment_number: u64) {
 337                 // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
 338                 // so that a remote monitor doesn't learn anything unless there is a malicious close.
 339                 // (only maybe, sadly we cant do the same for local info, as we need to be aware of
 340                 // timeouts)
 341                 for htlc in &htlc_outputs {
 342                         self.remote_hash_commitment_number.insert(htlc.payment_hash, commitment_number);
 343                 }
 344                 self.remote_claimable_outpoints.insert(unsigned_commitment_tx.txid(), htlc_outputs);
 345         }
 346
 347         /// Informs this monitor of the latest local (ie broadcastable) commitment transaction. The
 348         /// monitor watches for timeouts and may broadcast it if we approach such a timeout. Thus, it
 349         /// is important that any clones of this channel monitor (including remote clones) by kept
 350         /// up-to-date as our local commitment transaction is updated.
 351         /// Panics if set_their_to_self_delay has never been called.
 352         pub fn provide_latest_local_commitment_tx_info(&mut self, signed_commitment_tx: Transaction, local_keys: chan_utils::TxCreationKeys, feerate_per_kw: u64, htlc_outputs: Vec<(HTLCOutputInCommitment, Signature, Signature)>) {
 353                 assert!(self.their_to_self_delay.is_some());
 354                 self.prev_local_signed_commitment_tx = self.current_local_signed_commitment_tx.take();
 355                 self.current_local_signed_commitment_tx = Some(LocalSignedTx {
 356                         txid: signed_commitment_tx.txid(),
 357                         tx: signed_commitment_tx,
 358                         revocation_key: local_keys.revocation_key,
 359                         a_htlc_key: local_keys.a_htlc_key,
 360                         b_htlc_key: local_keys.b_htlc_key,
 361                         delayed_payment_key: local_keys.a_delayed_payment_key,
 362                         feerate_per_kw,
 363                         htlc_outputs,
 364                 });
 365         }
 366
 367         /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
 368         /// commitment_tx_infos which contain the payment hash have been revoked.
 369         pub fn provide_payment_preimage(&mut self, payment_hash: &[u8; 32], payment_preimage: &[u8; 32]) {
 370                 self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
 371         }
 372
 373         pub fn insert_combine(&mut self, mut other: ChannelMonitor) -> Result<(), HandleError> {
 374                 match self.funding_txo {
 375                         Some(txo) => if other.funding_txo.is_some() && other.funding_txo.unwrap() != txo {
 376                                 return Err(HandleError{err: "Funding transaction outputs are not identical!", msg: None});
 377                         },
 378                         None => if other.funding_txo.is_some() {
 379                                 self.funding_txo = other.funding_txo;
 380                         }
 381                 }
 382                 let other_min_secret = other.get_min_seen_secret();
 383                 let our_min_secret = self.get_min_seen_secret();
 384                 if our_min_secret > other_min_secret {
 385                         self.provide_secret(other_min_secret, other.get_secret(other_min_secret).unwrap(), None)?;
 386                 }
 387                 if our_min_secret >= other_min_secret {
 388                         self.their_cur_revocation_points = other.their_cur_revocation_points;
 389                         for (txid, htlcs) in other.remote_claimable_outpoints.drain() {
 390                                 self.remote_claimable_outpoints.insert(txid, htlcs);
 391                         }
 392                         if let Some(local_tx) = other.prev_local_signed_commitment_tx {
 393                                 self.prev_local_signed_commitment_tx = Some(local_tx);
 394                         }
 395                         if let Some(local_tx) = other.current_local_signed_commitment_tx {
 396                                 self.current_local_signed_commitment_tx = Some(local_tx);
 397                         }
 398                         self.payment_preimages = other.payment_preimages;
 399                 }
 400                 Ok(())
 401         }
 402
 403         /// Panics if commitment_transaction_number_obscure_factor doesn't fit in 48 bits
 404         pub fn set_commitment_obscure_factor(&mut self, commitment_transaction_number_obscure_factor: u64) {
 405                 assert!(commitment_transaction_number_obscure_factor < (1 << 48));
 406                 self.commitment_transaction_number_obscure_factor = commitment_transaction_number_obscure_factor;
 407         }
 408
 409         /// Allows this monitor to scan only for transactions which are applicable. Note that this is
 410         /// optional, without it this monitor cannot be used in an SPV client, but you may wish to
 411         /// avoid this (or call unset_funding_info) on a monitor you wish to send to a watchtower as it
 412         /// provides slightly better privacy.
 413         pub fn set_funding_info(&mut self, funding_txid: Sha256dHash, funding_output_index: u16) {
 414                 self.funding_txo = Some((funding_txid, funding_output_index));
 415         }
 416
 417         pub fn set_their_htlc_base_key(&mut self, their_htlc_base_key: &PublicKey) {
 418                 self.their_htlc_base_key = Some(their_htlc_base_key.clone());
 419         }
 420
 421         pub fn set_their_to_self_delay(&mut self, their_to_self_delay: u16) {
 422                 self.their_to_self_delay = Some(their_to_self_delay);
 423         }
 424
 425         pub fn unset_funding_info(&mut self) {
 426                 self.funding_txo = None;
 427         }
 428
 429         pub fn get_funding_txo(&self) -> Option<(Sha256dHash, u16)> {
 430                 self.funding_txo
 431         }
 432
 433         //TODO: Functions to serialize/deserialize (with different forms depending on which information
 434         //we want to leave out (eg funding_txo, etc).
 435
 436         /// Can only fail if idx is < get_min_seen_secret
 437         pub fn get_secret(&self, idx: u64) -> Result<[u8; 32], HandleError> {
 438                 for i in 0..self.old_secrets.len() {
 439                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 440                                 return Ok(ChannelMonitor::derive_secret(self.old_secrets[i].0, i as u8, idx))
 441                         }
 442                 }
 443                 assert!(idx < self.get_min_seen_secret());
 444                 Err(HandleError{err: "idx too low", msg: None})
 445         }
 446
 447         pub fn get_min_seen_secret(&self) -> u64 {
 448                 //TODO This can be optimized?
 449                 let mut min = 1 << 48;
 450                 for &(_, idx) in self.old_secrets.iter() {
 451                         if idx < min {
 452                                 min = idx;
 453                         }
 454                 }
 455                 min
 456         }
 457
 458         /// Attempts to claim a remote commitment transaction's outputs using the revocation key and
 459         /// data in remote_claimable_outpoints. Will directly claim any HTLC outputs which expire at a
 460         /// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 461         /// HTLC-Success/HTLC-Timeout transactions, and claim them using the revocation key (if
 462         /// applicable) as well.
 463         fn check_spend_remote_transaction(&self, tx: &Transaction, height: u32) -> Vec<Transaction> {
 464                 // Most secp and related errors trying to create keys means we have no hope of constructing
 465                 // a spend transaction...so we return no transactions to broadcast
 466                 let mut txn_to_broadcast = Vec::new();
 467                 macro_rules! ignore_error {
 468                         ( $thing : expr ) => {
 469                                 match $thing {
 470                                         Ok(a) => a,
 471                                         Err(_) => return txn_to_broadcast
 472                                 }
 473                         };
 474                 }
 475
 476                 let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 477                 let per_commitment_option = self.remote_claimable_outpoints.get(&commitment_txid);
 478
 479                 let commitment_number = (((tx.input[0].sequence as u64 & 0xffffff) << 3*8) | (tx.lock_time as u64 & 0xffffff)) ^ self.commitment_transaction_number_obscure_factor;
 480                 if commitment_number >= self.get_min_seen_secret() {
 481                         let secret = self.get_secret(commitment_number).unwrap();
 482                         let per_commitment_key = ignore_error!(SecretKey::from_slice(&self.secp_ctx, &secret));
 483                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 484                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 485                                         let per_commitment_point = ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key));
 486                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))),
 487                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key)))))
 488                                 },
 489                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 490                                         let per_commitment_point = ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key));
 491                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &revocation_base_key)),
 492                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &htlc_base_key)))
 493                                 },
 494                         };
 495                         let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key)), &self.delayed_payment_base_key));
 496                         let a_htlc_key = match self.their_htlc_base_key {
 497                                 None => return txn_to_broadcast,
 498                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key)), &their_htlc_base_key)),
 499                         };
 500
 501                         let revokeable_redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.our_to_self_delay, &delayed_key);
 502                         let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
 503
 504                         let mut total_value = 0;
 505                         let mut values = Vec::new();
 506                         let mut inputs = Vec::new();
 507                         let mut htlc_idxs = Vec::new();
 508
 509                         for (idx, outp) in tx.output.iter().enumerate() {
 510                                 if outp.script_pubkey == revokeable_p2wsh {
 511                                         inputs.push(TxIn {
 512                                                 prev_hash: commitment_txid,
 513                                                 prev_index: idx as u32,
 514                                                 script_sig: Script::new(),
 515                                                 sequence: 0xfffffffd,
 516                                                 witness: Vec::new(),
 517                                         });
 518                                         htlc_idxs.push(None);
 519                                         values.push(outp.value);
 520                                         total_value += outp.value;
 521                                         break; // There can only be one of these
 522                                 }
 523                         }
 524
 525                         macro_rules! sign_input {
 526                                 ($sighash_parts: expr, $input: expr, $htlc_idx: expr, $amount: expr) => {
 527                                         {
 528                                                 let (sig, redeemscript) = match self.key_storage {
 529                                                         KeyStorage::PrivMode { ref revocation_base_key, .. } => {
 530                                                                 let redeemscript = if $htlc_idx.is_none() { revokeable_redeemscript.clone() } else {
 531                                                                         let htlc = &per_commitment_option.unwrap()[$htlc_idx.unwrap()];
 532                                                                         chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey)
 533                                                                 };
 534                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 535                                                                 let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &revocation_base_key));
 536                                                                 (ignore_error!(self.secp_ctx.sign(&sighash, &revocation_key)), redeemscript)
 537                                                         },
 538                                                         KeyStorage::SigsMode { .. } => {
 539                                                                 unimplemented!();
 540                                                         }
 541                                                 };
 542                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 543                                                 $input.witness[0].push(SigHashType::All as u8);
 544                                                 if $htlc_idx.is_none() {
 545                                                         $input.witness.push(vec!(1));
 546                                                 } else {
 547                                                         $input.witness.push(revocation_pubkey.serialize().to_vec());
 548                                                 }
 549                                                 $input.witness.push(redeemscript.into_vec());
 550                                         }
 551                                 }
 552                         }
 553
 554                         if let Some(per_commitment_data) = per_commitment_option {
 555                                 inputs.reserve_exact(per_commitment_data.len());
 556
 557                                 for (idx, htlc) in per_commitment_data.iter().enumerate() {
 558                                         let expected_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 559                                         if htlc.transaction_output_index as usize >= tx.output.len() ||
 560                                                         tx.output[htlc.transaction_output_index as usize].value != htlc.amount_msat / 1000 ||
 561                                                         tx.output[htlc.transaction_output_index as usize].script_pubkey != expected_script.to_v0_p2wsh() {
 562                                                 return txn_to_broadcast; // Corrupted per_commitment_data, fuck this user
 563                                         }
 564                                         let input = TxIn {
 565                                                 prev_hash: commitment_txid,
 566                                                 prev_index: htlc.transaction_output_index,
 567                                                 script_sig: Script::new(),
 568                                                 sequence: 0xfffffffd,
 569                                                 witness: Vec::new(),
 570                                         };
 571                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 572                                                 inputs.push(input);
 573                                                 htlc_idxs.push(Some(idx));
 574                                                 values.push(tx.output[htlc.transaction_output_index as usize].value);
 575                                                 total_value += htlc.amount_msat / 1000;
 576                                         } else {
 577                                                 let mut single_htlc_tx = Transaction {
 578                                                         version: 2,
 579                                                         lock_time: 0,
 580                                                         input: vec![input],
 581                                                         output: vec!(TxOut {
 582                                                                 script_pubkey: self.destination_script.clone(),
 583                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 584                                                         }),
 585                                                 };
 586                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
 587                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], Some(idx), htlc.amount_msat / 1000);
 588                                                 txn_to_broadcast.push(single_htlc_tx); // TODO: This is not yet tested in ChannelManager!
 589                                         }
 590                                 }
 591                         }
 592
 593                         if !inputs.is_empty() || !txn_to_broadcast.is_empty() {
 594                                 // We're definitely a remote commitment transaction!
 595                                 // TODO: Register commitment_txid with the ChainWatchInterface!
 596                                 self.remote_htlc_outputs_on_chain.lock().unwrap().insert(commitment_txid, commitment_number);
 597                         }
 598                         if inputs.is_empty() { return txn_to_broadcast; } // Nothing to be done...probably a false positive/local tx
 599
 600                         let outputs = vec!(TxOut {
 601                                 script_pubkey: self.destination_script.clone(),
 602                                 value: total_value, //TODO: - fee
 603                         });
 604                         let mut spend_tx = Transaction {
 605                                 version: 2,
 606                                 lock_time: 0,
 607                                 input: inputs,
 608                                 output: outputs,
 609                         };
 610
 611                         let mut values_drain = values.drain(..);
 612                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 613
 614                         for (input, htlc_idx) in spend_tx.input.iter_mut().zip(htlc_idxs.iter()) {
 615                                 let value = values_drain.next().unwrap();
 616                                 sign_input!(sighash_parts, input, htlc_idx, value);
 617                         }
 618
 619                         txn_to_broadcast.push(spend_tx);
 620                 } else if let Some(per_commitment_data) = per_commitment_option {
 621                         if let Some(revocation_points) = self.their_cur_revocation_points {
 622                                 let revocation_point_option =
 623                                         if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
 624                                         else if let Some(point) = revocation_points.2.as_ref() {
 625                                                 if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
 626                                         } else { None };
 627                                 if let Some(revocation_point) = revocation_point_option {
 628                                         let (revocation_pubkey, b_htlc_key) = match self.key_storage {
 629                                                 KeyStorage::PrivMode { ref revocation_base_key, ref htlc_base_key } => {
 630                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &revocation_base_key)))),
 631                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &ignore_error!(PublicKey::from_secret_key(&self.secp_ctx, &htlc_base_key)))))
 632                                                 },
 633                                                 KeyStorage::SigsMode { ref revocation_base_key, ref htlc_base_key, .. } => {
 634                                                         (ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &revocation_base_key)),
 635                                                         ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &htlc_base_key)))
 636                                                 },
 637                                         };
 638                                         let a_htlc_key = match self.their_htlc_base_key {
 639                                                 None => return txn_to_broadcast,
 640                                                 Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
 641                                         };
 642
 643                                         let mut total_value = 0;
 644                                         let mut values = Vec::new();
 645                                         let mut inputs = Vec::new();
 646
 647                                         macro_rules! sign_input {
 648                                                 ($sighash_parts: expr, $input: expr, $amount: expr, $preimage: expr) => {
 649                                                         {
 650                                                                 let (sig, redeemscript) = match self.key_storage {
 651                                                                         KeyStorage::PrivMode { ref htlc_base_key, .. } => {
 652                                                                                 let htlc = &per_commitment_option.unwrap()[$input.sequence as usize];
 653                                                                                 let redeemscript = chan_utils::get_htlc_redeemscript_with_explicit_keys(htlc, &a_htlc_key, &b_htlc_key, &revocation_pubkey);
 654                                                                                 let sighash = ignore_error!(Message::from_slice(&$sighash_parts.sighash_all(&$input, &redeemscript, $amount)[..]));
 655                                                                                 let htlc_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &htlc_base_key));
 656                                                                                 (ignore_error!(self.secp_ctx.sign(&sighash, &htlc_key)), redeemscript)
 657                                                                         },
 658                                                                         KeyStorage::SigsMode { .. } => {
 659                                                                                 unimplemented!();
 660                                                                         }
 661                                                                 };
 662                                                                 $input.witness.push(sig.serialize_der(&self.secp_ctx).to_vec());
 663                                                                 $input.witness[0].push(SigHashType::All as u8);
 664                                                                 $input.witness.push($preimage);
 665                                                                 $input.witness.push(redeemscript.into_vec());
 666                                                         }
 667                                                 }
 668                                         }
 669
 670                                         for (idx, htlc) in per_commitment_data.iter().enumerate() {
 671                                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
 672                                                         let input = TxIn {
 673                                                                 prev_hash: commitment_txid,
 674                                                                 prev_index: htlc.transaction_output_index,
 675                                                                 script_sig: Script::new(),
 676                                                                 sequence: idx as u32, // reset to 0xfffffffd in sign_input
 677                                                                 witness: Vec::new(),
 678                                                         };
 679                                                         if htlc.cltv_expiry > height + CLTV_SHARED_CLAIM_BUFFER {
 680                                                                 inputs.push(input);
 681                                                                 values.push((tx.output[htlc.transaction_output_index as usize].value, payment_preimage));
 682                                                                 total_value += htlc.amount_msat / 1000;
 683                                                         } else {
 684                                                                 let mut single_htlc_tx = Transaction {
 685                                                                         version: 2,
 686                                                                         lock_time: 0,
 687                                                                         input: vec![input],
 688                                                                         output: vec!(TxOut {
 689                                                                                 script_pubkey: self.destination_script.clone(),
 690                                                                                 value: htlc.amount_msat / 1000, //TODO: - fee
 691                                                                         }),
 692                                                                 };
 693                                                                 let sighash_parts = bip143::SighashComponents::new(&single_htlc_tx);
 694                                                                 sign_input!(sighash_parts, single_htlc_tx.input[0], htlc.amount_msat / 1000, payment_preimage.to_vec());
 695                                                                 txn_to_broadcast.push(single_htlc_tx);
 696                                                         }
 697                                                 }
 698                                         }
 699
 700                                         if inputs.is_empty() { return txn_to_broadcast; } // Nothing to be done...probably a false positive/local tx
 701
 702                                         let outputs = vec!(TxOut {
 703                                                 script_pubkey: self.destination_script.clone(),
 704                                                 value: total_value, //TODO: - fee
 705                                         });
 706                                         let mut spend_tx = Transaction {
 707                                                 version: 2,
 708                                                 lock_time: 0,
 709                                                 input: inputs,
 710                                                 output: outputs,
 711                                         };
 712
 713                                         let mut values_drain = values.drain(..);
 714                                         let sighash_parts = bip143::SighashComponents::new(&spend_tx);
 715
 716                                         for input in spend_tx.input.iter_mut() {
 717                                                 let value = values_drain.next().unwrap();
 718                                                 sign_input!(sighash_parts, input, value.0, value.1.to_vec());
 719                                         }
 720
 721                                         txn_to_broadcast.push(spend_tx);
 722                                 }
 723                         }
 724                 } else {
 725                         //TODO: For each input check if its in our remote_htlc_outputs_on_chain map!
 726                 }
 727
 728                 txn_to_broadcast
 729         }
 730
 731         fn broadcast_by_local_state(&self, local_tx: &LocalSignedTx) -> Vec<Transaction> {
 732                 let mut res = Vec::with_capacity(local_tx.htlc_outputs.len());
 733
 734                 for &(ref htlc, ref their_sig, ref our_sig) in local_tx.htlc_outputs.iter() {
 735                         if htlc.offered {
 736                                 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);
 737
 738                                 htlc_timeout_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
 739
 740                                 htlc_timeout_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
 741                                 htlc_timeout_tx.input[0].witness[1].push(SigHashType::All as u8);
 742                                 htlc_timeout_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
 743                                 htlc_timeout_tx.input[0].witness[2].push(SigHashType::All as u8);
 744
 745                                 htlc_timeout_tx.input[0].witness.push(Vec::new());
 746                                 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_vec());
 747
 748                                 res.push(htlc_timeout_tx);
 749                         } else {
 750                                 if let Some(payment_preimage) = self.payment_preimages.get(&htlc.payment_hash) {
 751                                         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);
 752
 753                                         htlc_success_tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
 754
 755                                         htlc_success_tx.input[0].witness.push(their_sig.serialize_der(&self.secp_ctx).to_vec());
 756                                         htlc_success_tx.input[0].witness[1].push(SigHashType::All as u8);
 757                                         htlc_success_tx.input[0].witness.push(our_sig.serialize_der(&self.secp_ctx).to_vec());
 758                                         htlc_success_tx.input[0].witness[2].push(SigHashType::All as u8);
 759
 760                                         htlc_success_tx.input[0].witness.push(payment_preimage.to_vec());
 761                                         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_vec());
 762
 763                                         res.push(htlc_success_tx);
 764                                 }
 765                         }
 766                 }
 767
 768                 res
 769         }
 770
 771         /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
 772         /// revoked using data in local_claimable_outpoints.
 773         /// Should not be used if check_spend_revoked_transaction succeeds.
 774         fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> Vec<Transaction> {
 775                 let commitment_txid = tx.txid();
 776                 if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
 777                         if local_tx.txid == commitment_txid {
 778                                 return self.broadcast_by_local_state(local_tx);
 779                         }
 780                 }
 781                 if let &Some(ref local_tx) = &self.prev_local_signed_commitment_tx {
 782                         if local_tx.txid == commitment_txid {
 783                                 return self.broadcast_by_local_state(local_tx);
 784                         }
 785                 }
 786                 Vec::new()
 787         }
 788
 789         fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface) {
 790                 for tx in txn_matched {
 791                         for txin in tx.input.iter() {
 792                                 if self.funding_txo.is_none() || (txin.prev_hash == self.funding_txo.unwrap().0 && txin.prev_index == self.funding_txo.unwrap().1 as u32) {
 793                                         let mut txn = self.check_spend_remote_transaction(tx, height);
 794                                         if txn.is_empty() {
 795                                                 txn = self.check_spend_local_transaction(tx, height);
 796                                         }
 797                                         for tx in txn.iter() {
 798                                                 broadcaster.broadcast_transaction(tx);
 799                                         }
 800                                 }
 801                         }
 802                 }
 803                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 804                         let mut needs_broadcast = false;
 805                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
 806                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
 807                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
 808                                                 needs_broadcast = true;
 809                                         }
 810                                 }
 811                         }
 812
 813                         if needs_broadcast {
 814                                 broadcaster.broadcast_transaction(&cur_local_tx.tx);
 815                                 for tx in self.broadcast_by_local_state(&cur_local_tx) {
 816                                         broadcaster.broadcast_transaction(&tx);
 817                                 }
 818                         }
 819                 }
 820         }
 821
 822         pub fn would_broadcast_at_height(&self, height: u32) -> bool {
 823                 if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 824                         for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
 825                                 if htlc.cltv_expiry <= height + CLTV_CLAIM_BUFFER {
 826                                         if htlc.offered || self.payment_preimages.contains_key(&htlc.payment_hash) {
 827                                                 return true;
 828                                         }
 829                                 }
 830                         }
 831                 }
 832                 false
 833         }
 834 }
 835
 836 #[cfg(test)]
 837 mod tests {
 838         use bitcoin::util::misc::hex_bytes;
 839         use bitcoin::blockdata::script::Script;
 840         use bitcoin::util::hash::{Hash160,Sha256dHash};
 841         use bitcoin::blockdata::transaction::Transaction;
 842         use ln::channelmonitor::ChannelMonitor;
 843         use ln::channelmonitor::LocalSignedTx;
 844         use ln::chan_utils::HTLCOutputInCommitment;
 845         use secp256k1::key::{SecretKey,PublicKey};
 846         use secp256k1::{Secp256k1, Signature};
 847         use rand::{thread_rng,Rng};
 848
 849         #[test]
 850         fn test_per_commitment_storage() {
 851                 // Test vectors from BOLT 3:
 852                 let mut secrets: Vec<[u8; 32]> = Vec::new();
 853                 let mut monitor: ChannelMonitor;
 854                 let secp_ctx = Secp256k1::new();
 855
 856                 macro_rules! test_secrets {
 857                         () => {
 858                                 let mut idx = 281474976710655;
 859                                 for secret in secrets.iter() {
 860                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
 861                                         idx -= 1;
 862                                 }
 863                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
 864                                 assert!(monitor.get_secret(idx).is_err());
 865                         };
 866                 }
 867
 868                 {
 869                         // insert_secret correct sequence
 870                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
 871                         secrets.clear();
 872
 873                         secrets.push([0; 32]);
 874                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
 875                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
 876                         test_secrets!();
 877
 878                         secrets.push([0; 32]);
 879                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
 880                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
 881                         test_secrets!();
 882
 883                         secrets.push([0; 32]);
 884                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
 885                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
 886                         test_secrets!();
 887
 888                         secrets.push([0; 32]);
 889                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
 890                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
 891                         test_secrets!();
 892
 893                         secrets.push([0; 32]);
 894                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
 895                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
 896                         test_secrets!();
 897
 898                         secrets.push([0; 32]);
 899                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
 900                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
 901                         test_secrets!();
 902
 903                         secrets.push([0; 32]);
 904                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
 905                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
 906                         test_secrets!();
 907
 908                         secrets.push([0; 32]);
 909                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
 910                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap();
 911                         test_secrets!();
 912                 }
 913
 914                 {
 915                         // insert_secret #1 incorrect
 916                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
 917                         secrets.clear();
 918
 919                         secrets.push([0; 32]);
 920                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
 921                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
 922                         test_secrets!();
 923
 924                         secrets.push([0; 32]);
 925                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
 926                         assert_eq!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap_err().err,
 927                                         "Previous secret did not match new one");
 928                 }
 929
 930                 {
 931                         // insert_secret #2 incorrect (#1 derived from incorrect)
 932                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
 933                         secrets.clear();
 934
 935                         secrets.push([0; 32]);
 936                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
 937                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
 938                         test_secrets!();
 939
 940                         secrets.push([0; 32]);
 941                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
 942                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
 943                         test_secrets!();
 944
 945                         secrets.push([0; 32]);
 946                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
 947                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
 948                         test_secrets!();
 949
 950                         secrets.push([0; 32]);
 951                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
 952                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
 953                                         "Previous secret did not match new one");
 954                 }
 955
 956                 {
 957                         // insert_secret #3 incorrect
 958                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
 959                         secrets.clear();
 960
 961                         secrets.push([0; 32]);
 962                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
 963                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
 964                         test_secrets!();
 965
 966                         secrets.push([0; 32]);
 967                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
 968                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
 969                         test_secrets!();
 970
 971                         secrets.push([0; 32]);
 972                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
 973                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
 974                         test_secrets!();
 975
 976                         secrets.push([0; 32]);
 977                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
 978                         assert_eq!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap_err().err,
 979                                         "Previous secret did not match new one");
 980                 }
 981
 982                 {
 983                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
 984                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
 985                         secrets.clear();
 986
 987                         secrets.push([0; 32]);
 988                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
 989                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
 990                         test_secrets!();
 991
 992                         secrets.push([0; 32]);
 993                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
 994                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
 995                         test_secrets!();
 996
 997                         secrets.push([0; 32]);
 998                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
 999                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1000                         test_secrets!();
1001
1002                         secrets.push([0; 32]);
1003                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1004                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1005                         test_secrets!();
1006
1007                         secrets.push([0; 32]);
1008                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1009                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1010                         test_secrets!();
1011
1012                         secrets.push([0; 32]);
1013                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1014                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1015                         test_secrets!();
1016
1017                         secrets.push([0; 32]);
1018                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1019                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1020                         test_secrets!();
1021
1022                         secrets.push([0; 32]);
1023                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1024                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1025                                         "Previous secret did not match new one");
1026                 }
1027
1028                 {
1029                         // insert_secret #5 incorrect
1030                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1031                         secrets.clear();
1032
1033                         secrets.push([0; 32]);
1034                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1035                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1036                         test_secrets!();
1037
1038                         secrets.push([0; 32]);
1039                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1040                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1041                         test_secrets!();
1042
1043                         secrets.push([0; 32]);
1044                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1045                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1046                         test_secrets!();
1047
1048                         secrets.push([0; 32]);
1049                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1050                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1051                         test_secrets!();
1052
1053                         secrets.push([0; 32]);
1054                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1055                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1056                         test_secrets!();
1057
1058                         secrets.push([0; 32]);
1059                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1060                         assert_eq!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap_err().err,
1061                                         "Previous secret did not match new one");
1062                 }
1063
1064                 {
1065                         // insert_secret #6 incorrect (5 derived from incorrect)
1066                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1067                         secrets.clear();
1068
1069                         secrets.push([0; 32]);
1070                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1071                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1072                         test_secrets!();
1073
1074                         secrets.push([0; 32]);
1075                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1076                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1077                         test_secrets!();
1078
1079                         secrets.push([0; 32]);
1080                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1081                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1082                         test_secrets!();
1083
1084                         secrets.push([0; 32]);
1085                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1086                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1087                         test_secrets!();
1088
1089                         secrets.push([0; 32]);
1090                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1091                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1092                         test_secrets!();
1093
1094                         secrets.push([0; 32]);
1095                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1096                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1097                         test_secrets!();
1098
1099                         secrets.push([0; 32]);
1100                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1101                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1102                         test_secrets!();
1103
1104                         secrets.push([0; 32]);
1105                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1106                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1107                                         "Previous secret did not match new one");
1108                 }
1109
1110                 {
1111                         // insert_secret #7 incorrect
1112                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1113                         secrets.clear();
1114
1115                         secrets.push([0; 32]);
1116                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1117                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1118                         test_secrets!();
1119
1120                         secrets.push([0; 32]);
1121                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1122                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1123                         test_secrets!();
1124
1125                         secrets.push([0; 32]);
1126                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1127                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1128                         test_secrets!();
1129
1130                         secrets.push([0; 32]);
1131                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1132                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1133                         test_secrets!();
1134
1135                         secrets.push([0; 32]);
1136                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1137                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1138                         test_secrets!();
1139
1140                         secrets.push([0; 32]);
1141                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1142                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1143                         test_secrets!();
1144
1145                         secrets.push([0; 32]);
1146                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1147                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1148                         test_secrets!();
1149
1150                         secrets.push([0; 32]);
1151                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1152                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1153                                         "Previous secret did not match new one");
1154                 }
1155
1156                 {
1157                         // insert_secret #8 incorrect
1158                         monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1159                         secrets.clear();
1160
1161                         secrets.push([0; 32]);
1162                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1163                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone(), None).unwrap();
1164                         test_secrets!();
1165
1166                         secrets.push([0; 32]);
1167                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1168                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone(), None).unwrap();
1169                         test_secrets!();
1170
1171                         secrets.push([0; 32]);
1172                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1173                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone(), None).unwrap();
1174                         test_secrets!();
1175
1176                         secrets.push([0; 32]);
1177                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1178                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone(), None).unwrap();
1179                         test_secrets!();
1180
1181                         secrets.push([0; 32]);
1182                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1183                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone(), None).unwrap();
1184                         test_secrets!();
1185
1186                         secrets.push([0; 32]);
1187                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1188                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone(), None).unwrap();
1189                         test_secrets!();
1190
1191                         secrets.push([0; 32]);
1192                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1193                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone(), None).unwrap();
1194                         test_secrets!();
1195
1196                         secrets.push([0; 32]);
1197                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex_bytes("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1198                         assert_eq!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone(), None).unwrap_err().err,
1199                                         "Previous secret did not match new one");
1200                 }
1201         }
1202
1203         macro_rules! gen_local_tx {
1204                 ($hex : expr, $monitor : expr, $htlcs : expr, $rng : expr, $preimage : expr, $hash : expr) => {
1205                         {
1206                                 let mut htlcs = Vec::new();
1207                                 for _i in 0..$htlcs {
1208                                         $rng.fill_bytes(&mut $preimage);
1209                                         $hash[0..20].clone_from_slice(&Hash160::from_data(&$preimage)[0..20]);
1210                                         $monitor.provide_payment_preimage(&$hash, &$preimage);
1211                                         htlcs.push((HTLCOutputInCommitment {
1212                                                 offered : true,
1213                                                 amount_msat : 0,
1214                                                 cltv_expiry : 0,
1215                                                 payment_hash : $hash.clone(),
1216                                                 transaction_output_index : 0,
1217                                         }, Signature::from_der(&Secp256k1::new(), $hex).unwrap(),
1218                                         Signature::from_der(&Secp256k1::new(), $hex).unwrap()))
1219                                 }
1220
1221                                 Some(LocalSignedTx {
1222                                         txid: Sha256dHash::from_data(&[]),
1223                                         tx: Transaction {
1224                                                 version: 0,
1225                                                 lock_time: 0,
1226                                                 input: Vec::new(),
1227                                                 output: Vec::new(),
1228                                         },
1229                                         revocation_key: PublicKey::new(),
1230                                         a_htlc_key: PublicKey::new(),
1231                                         b_htlc_key: PublicKey::new(),
1232                                         delayed_payment_key: PublicKey::new(),
1233                                         feerate_per_kw: 0,
1234                                         htlc_outputs: htlcs,
1235                                 })
1236                         }
1237                 }
1238         }
1239
1240         macro_rules! gen_remote_outpoints {
1241                 ($monitor : expr, $tx : expr, $htlcs : expr, $rng : expr, $preimage : expr, $hash: expr, $number : expr) => {
1242                         {
1243                                 let mut commitment_number = $number;
1244                                 for i in 0..$tx {
1245                                         let tx_zero = Transaction {
1246                                                 version : 0,
1247                                                 lock_time : i,
1248                                                 input : Vec::new(),
1249                                                 output: Vec::new(),
1250                                         };
1251
1252                                         let mut htlcs = Vec::new();
1253                                         for _i in 0..$htlcs {
1254                                                 $rng.fill_bytes(&mut $preimage);
1255                                                 $hash[0..20].clone_from_slice(&Hash160::from_data(&$preimage)[0..20]);
1256                                                 $monitor.provide_payment_preimage(&$hash, &$preimage);
1257                                                 htlcs.push(HTLCOutputInCommitment {
1258                                                         offered : true,
1259                                                         amount_msat : 0,
1260                                                         cltv_expiry : 0,
1261                                                         payment_hash : $hash.clone(),
1262                                                         transaction_output_index : 0,
1263                                                 });
1264                                         }
1265                                         commitment_number -= 1;
1266                                         $monitor.provide_latest_remote_commitment_tx_info(&tx_zero, htlcs, commitment_number);
1267                                 }
1268                         }
1269                 }
1270         }
1271
1272         #[test]
1273         fn test_prune_preimages() {
1274                 let mut secret = [0; 32];
1275                 secret[0..32].clone_from_slice(&hex_bytes("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1276                 let secp_ctx = Secp256k1::new();
1277                 let mut preimage: [u8;32] = [0;32];
1278                 let mut hash: [u8;32] = [0;32];
1279                 let mut rng  = thread_rng();
1280
1281                 {
1282                         // insert 30 random hash, 10 from local, 10 from remote, prune 30/50
1283                         let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1284
1285                         for _i in 0..30 {
1286                                 rng.fill_bytes(&mut preimage);
1287                                 hash[0..20].clone_from_slice(&Hash160::from_data(&preimage)[0..20]);
1288                                 monitor.provide_payment_preimage(&hash, &preimage);
1289                         }
1290                         monitor.current_local_signed_commitment_tx = gen_local_tx!(&hex_bytes("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..], monitor, 10, rng, preimage, hash);
1291                         gen_remote_outpoints!(monitor, 1, 10, rng, preimage, hash, 281474976710654);
1292                         monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1293                         assert_eq!(monitor.payment_preimages.len(), 20);
1294                 }
1295
1296                 {
1297                         // insert 30 random hash, prune 30/30
1298                         let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1299
1300                         for _i in 0..30 {
1301                                 rng.fill_bytes(&mut preimage);
1302                                 hash[0..20].clone_from_slice(&Hash160::from_data(&preimage)[0..20]);
1303                                 monitor.provide_payment_preimage(&hash, &preimage);
1304                         }
1305                         monitor.current_local_signed_commitment_tx = gen_local_tx!(&hex_bytes("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..], monitor, 0, rng, preimage, hash);
1306                         gen_remote_outpoints!(monitor, 0, 0, rng, preimage, hash, 281474976710655);
1307                         monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1308                         assert_eq!(monitor.payment_preimages.len(), 0);
1309                 }
1310
1311                 {
1312                         // insert 30 random hash, 25 on 5 remotes, prune 30/55
1313                         let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1314
1315                         for _i in 0..30 {
1316                                 rng.fill_bytes(&mut preimage);
1317                                 hash[0..20].clone_from_slice(&Hash160::from_data(&preimage)[0..20]);
1318                                 monitor.provide_payment_preimage(&hash, &preimage);
1319                         }
1320                         monitor.current_local_signed_commitment_tx = gen_local_tx!(&hex_bytes("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..], monitor, 0, rng, preimage, hash);
1321                         gen_remote_outpoints!(monitor, 5, 5, rng, preimage, hash, 281474976710654);
1322                         monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1323                         assert_eq!(monitor.payment_preimages.len(), 25);
1324                 }
1325
1326                 {
1327                         // insert 30 random hash, 25 from local, prune 30/55
1328                         let mut monitor = ChannelMonitor::new(&SecretKey::from_slice(&secp_ctx, &[42; 32]).unwrap(), &PublicKey::new(), &SecretKey::from_slice(&secp_ctx, &[43; 32]).unwrap(), 0, Script::new());
1329
1330                         for _i in 0..30 {
1331                                 rng.fill_bytes(&mut preimage);
1332                                 hash[0..20].clone_from_slice(&Hash160::from_data(&preimage)[0..20]);
1333                                 monitor.provide_payment_preimage(&hash, &preimage);
1334                         }
1335                         monitor.current_local_signed_commitment_tx = gen_local_tx!(&hex_bytes("3045022100fa86fa9a36a8cd6a7bb8f06a541787d51371d067951a9461d5404de6b928782e02201c8b7c334c10aed8976a3a465be9a28abff4cb23acbf00022295b378ce1fa3cd").unwrap()[..], monitor, 25, rng, preimage, hash);
1336                         gen_remote_outpoints!(monitor, 0, 0, rng, preimage, hash, 281474976710655);
1337                         monitor.provide_secret(281474976710655, secret.clone(), None).unwrap();
1338                         assert_eq!(monitor.payment_preimages.len(), 25);
1339                 }
1340         }
1341
1342         // Further testing is done in the ChannelManager integration tests.
1343 }