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

   1 //! The logic to build claims and bump in-flight transactions until confirmations.
   2 //!
   3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
   4 //! building, tracking, bumping and notifications functions.
   5
   6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
   7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
   8 use bitcoin::blockdata::script::Script;
   9
  10 use bitcoin::hash_types::Txid;
  11
  12 use bitcoin::secp256k1::{Secp256k1, Signature};
  13 use bitcoin::secp256k1;
  14
  15 use ln::msgs::DecodeError;
  16 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  17 use ln::channelmanager::PaymentPreimage;
  18 use ln::chan_utils;
  19 use ln::chan_utils::{TxCreationKeys, LocalCommitmentTransaction};
  20 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  21 use chain::keysinterface::ChannelKeys;
  22 use util::logger::Logger;
  23 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
  24 use util::byte_utils;
  25
  26 use std::collections::{HashMap, hash_map};
  27 use std::sync::Arc;
  28 use std::cmp;
  29 use std::ops::Deref;
  30
  31 const MAX_ALLOC_SIZE: usize = 64*1024;
  32
  33 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  34 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  35 #[derive(Clone, PartialEq)]
  36 enum OnchainEvent {
  37         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  38         /// bump-txn candidate buffer.
  39         Claim {
  40                 claim_request: Txid,
  41         },
  42         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
  43         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  44         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  45         ContentiousOutpoint {
  46                 outpoint: BitcoinOutPoint,
  47                 input_material: InputMaterial,
  48         }
  49 }
  50
  51 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
  52 #[derive(Clone, PartialEq)]
  53 pub struct ClaimTxBumpMaterial {
  54         // At every block tick, used to check if pending claiming tx is taking too
  55         // much time for confirmation and we need to bump it.
  56         height_timer: Option<u32>,
  57         // Tracked in case of reorg to wipe out now-superflous bump material
  58         feerate_previous: u64,
  59         // Soonest timelocks among set of outpoints claimed, used to compute
  60         // a priority of not feerate
  61         soonest_timelock: u32,
  62         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
  63         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
  64 }
  65
  66 impl Writeable for ClaimTxBumpMaterial  {
  67         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  68                 self.height_timer.write(writer)?;
  69                 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
  70                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
  71                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
  72                 for (outp, tx_material) in self.per_input_material.iter() {
  73                         outp.write(writer)?;
  74                         tx_material.write(writer)?;
  75                 }
  76                 Ok(())
  77         }
  78 }
  79
  80 impl Readable for ClaimTxBumpMaterial {
  81         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  82                 let height_timer = Readable::read(reader)?;
  83                 let feerate_previous = Readable::read(reader)?;
  84                 let soonest_timelock = Readable::read(reader)?;
  85                 let per_input_material_len: u64 = Readable::read(reader)?;
  86                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
  87                 for _ in 0 ..per_input_material_len {
  88                         let outpoint = Readable::read(reader)?;
  89                         let input_material = Readable::read(reader)?;
  90                         per_input_material.insert(outpoint, input_material);
  91                 }
  92                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
  93         }
  94 }
  95
  96 #[derive(PartialEq, Clone, Copy)]
  97 pub(crate) enum InputDescriptors {
  98         RevokedOfferedHTLC,
  99         RevokedReceivedHTLC,
 100         OfferedHTLC,
 101         ReceivedHTLC,
 102         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 103 }
 104
 105 impl Writeable for InputDescriptors {
 106         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 107                 match self {
 108                         &InputDescriptors::RevokedOfferedHTLC => {
 109                                 writer.write_all(&[0; 1])?;
 110                         },
 111                         &InputDescriptors::RevokedReceivedHTLC => {
 112                                 writer.write_all(&[1; 1])?;
 113                         },
 114                         &InputDescriptors::OfferedHTLC => {
 115                                 writer.write_all(&[2; 1])?;
 116                         },
 117                         &InputDescriptors::ReceivedHTLC => {
 118                                 writer.write_all(&[3; 1])?;
 119                         }
 120                         &InputDescriptors::RevokedOutput => {
 121                                 writer.write_all(&[4; 1])?;
 122                         }
 123                 }
 124                 Ok(())
 125         }
 126 }
 127
 128 impl Readable for InputDescriptors {
 129         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 130                 let input_descriptor = match <u8 as Readable>::read(reader)? {
 131                         0 => {
 132                                 InputDescriptors::RevokedOfferedHTLC
 133                         },
 134                         1 => {
 135                                 InputDescriptors::RevokedReceivedHTLC
 136                         },
 137                         2 => {
 138                                 InputDescriptors::OfferedHTLC
 139                         },
 140                         3 => {
 141                                 InputDescriptors::ReceivedHTLC
 142                         },
 143                         4 => {
 144                                 InputDescriptors::RevokedOutput
 145                         }
 146                         _ => return Err(DecodeError::InvalidValue),
 147                 };
 148                 Ok(input_descriptor)
 149         }
 150 }
 151
 152 macro_rules! subtract_high_prio_fee {
 153         ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 154                 {
 155                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
 156                         let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
 157                         if $value <= fee {
 158                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 159                                 fee = $used_feerate * ($predicted_weight as u64) / 1000;
 160                                 if $value <= fee {
 161                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 162                                         fee = $used_feerate * ($predicted_weight as u64) / 1000;
 163                                         if $value <= fee {
 164                                                 log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 165                                                         fee, $value);
 166                                                 false
 167                                         } else {
 168                                                 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 169                                                         $value);
 170                                                 $value -= fee;
 171                                                 true
 172                                         }
 173                                 } else {
 174                                         log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 175                                                 $value);
 176                                         $value -= fee;
 177                                         true
 178                                 }
 179                         } else {
 180                                 $value -= fee;
 181                                 true
 182                         }
 183                 }
 184         }
 185 }
 186
 187 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 188         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 189                 match Readable::read(reader)? {
 190                         0u8 => Ok(None),
 191                         1u8 => {
 192                                 let vlen: u64 = Readable::read(reader)?;
 193                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
 194                                 for _ in 0..vlen {
 195                                         ret.push(match Readable::read(reader)? {
 196                                                 0u8 => None,
 197                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 198                                                 _ => return Err(DecodeError::InvalidValue)
 199                                         });
 200                                 }
 201                                 Ok(Some(ret))
 202                         },
 203                         _ => Err(DecodeError::InvalidValue),
 204                 }
 205         }
 206 }
 207
 208 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 209         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 210                 match self {
 211                         &Some(ref vec) => {
 212                                 1u8.write(writer)?;
 213                                 (vec.len() as u64).write(writer)?;
 214                                 for opt in vec.iter() {
 215                                         match opt {
 216                                                 &Some((ref idx, ref sig)) => {
 217                                                         1u8.write(writer)?;
 218                                                         (*idx as u64).write(writer)?;
 219                                                         sig.write(writer)?;
 220                                                 },
 221                                                 &None => 0u8.write(writer)?,
 222                                         }
 223                                 }
 224                         },
 225                         &None => 0u8.write(writer)?,
 226                 }
 227                 Ok(())
 228         }
 229 }
 230
 231
 232 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 233 /// do RBF bumping if possible.
 234 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 235         destination_script: Script,
 236         local_commitment: Option<LocalCommitmentTransaction>,
 237         // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
 238         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 239         // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
 240         // the commitment transaction).
 241         local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 242         prev_local_commitment: Option<LocalCommitmentTransaction>,
 243         prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 244         on_local_tx_csv: u16,
 245
 246         key_storage: ChanSigner,
 247
 248         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 249         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 250         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 251         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 252         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 253         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 254         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 255         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 256         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 257         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 258         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 259         #[cfg(test)] // Used in functional_test to verify sanitization
 260         pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 261         #[cfg(not(test))]
 262         pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 263
 264         // Used to link outpoints claimed in a connected block to a pending claim request.
 265         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 266         // Value is (pending claim request identifier, confirmation_block), identifier
 267         // is txid of the initial claiming transaction and is immutable until outpoint is
 268         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 269         // block with output gets disconnected.
 270         #[cfg(test)] // Used in functional_test to verify sanitization
 271         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 272         #[cfg(not(test))]
 273         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 274
 275         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 276
 277         secp_ctx: Secp256k1<secp256k1::All>,
 278         logger: Arc<Logger>
 279 }
 280
 281 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
 282         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 283                 self.destination_script.write(writer)?;
 284                 self.local_commitment.write(writer)?;
 285                 self.local_htlc_sigs.write(writer)?;
 286                 self.prev_local_commitment.write(writer)?;
 287                 self.prev_local_htlc_sigs.write(writer)?;
 288
 289                 self.on_local_tx_csv.write(writer)?;
 290
 291                 self.key_storage.write(writer)?;
 292
 293                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 294                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 295                         ancestor_claim_txid.write(writer)?;
 296                         claim_tx_data.write(writer)?;
 297                 }
 298
 299                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 300                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 301                         outp.write(writer)?;
 302                         claim_and_height.0.write(writer)?;
 303                         claim_and_height.1.write(writer)?;
 304                 }
 305
 306                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 307                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 308                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 309                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 310                         for ev in events.iter() {
 311                                 match *ev {
 312                                         OnchainEvent::Claim { ref claim_request } => {
 313                                                 writer.write_all(&[0; 1])?;
 314                                                 claim_request.write(writer)?;
 315                                         },
 316                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 317                                                 writer.write_all(&[1; 1])?;
 318                                                 outpoint.write(writer)?;
 319                                                 input_material.write(writer)?;
 320                                         }
 321                                 }
 322                         }
 323                 }
 324                 Ok(())
 325         }
 326 }
 327
 328 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
 329         fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
 330                 let destination_script = Readable::read(reader)?;
 331
 332                 let local_commitment = Readable::read(reader)?;
 333                 let local_htlc_sigs = Readable::read(reader)?;
 334                 let prev_local_commitment = Readable::read(reader)?;
 335                 let prev_local_htlc_sigs = Readable::read(reader)?;
 336
 337                 let on_local_tx_csv = Readable::read(reader)?;
 338
 339                 let key_storage = Readable::read(reader)?;
 340
 341                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 342                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 343                 for _ in 0..pending_claim_requests_len {
 344                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 345                 }
 346
 347                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 348                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 349                 for _ in 0..claimable_outpoints_len {
 350                         let outpoint = Readable::read(reader)?;
 351                         let ancestor_claim_txid = Readable::read(reader)?;
 352                         let height = Readable::read(reader)?;
 353                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 354                 }
 355                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 356                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 357                 for _ in 0..waiting_threshold_conf_len {
 358                         let height_target = Readable::read(reader)?;
 359                         let events_len: u64 = Readable::read(reader)?;
 360                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 361                         for _ in 0..events_len {
 362                                 let ev = match <u8 as Readable>::read(reader)? {
 363                                         0 => {
 364                                                 let claim_request = Readable::read(reader)?;
 365                                                 OnchainEvent::Claim {
 366                                                         claim_request
 367                                                 }
 368                                         },
 369                                         1 => {
 370                                                 let outpoint = Readable::read(reader)?;
 371                                                 let input_material = Readable::read(reader)?;
 372                                                 OnchainEvent::ContentiousOutpoint {
 373                                                         outpoint,
 374                                                         input_material
 375                                                 }
 376                                         }
 377                                         _ => return Err(DecodeError::InvalidValue),
 378                                 };
 379                                 events.push(ev);
 380                         }
 381                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 382                 }
 383
 384                 Ok(OnchainTxHandler {
 385                         destination_script,
 386                         local_commitment,
 387                         local_htlc_sigs,
 388                         prev_local_commitment,
 389                         prev_local_htlc_sigs,
 390                         on_local_tx_csv,
 391                         key_storage,
 392                         claimable_outpoints,
 393                         pending_claim_requests,
 394                         onchain_events_waiting_threshold_conf,
 395                         secp_ctx: Secp256k1::new(),
 396                         logger,
 397                 })
 398         }
 399 }
 400
 401 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 402         pub(super) fn new(destination_script: Script, keys: ChanSigner, on_local_tx_csv: u16, logger: Arc<Logger>) -> Self {
 403
 404                 let key_storage = keys;
 405
 406                 OnchainTxHandler {
 407                         destination_script,
 408                         local_commitment: None,
 409                         local_htlc_sigs: None,
 410                         prev_local_commitment: None,
 411                         prev_local_htlc_sigs: None,
 412                         on_local_tx_csv,
 413                         key_storage,
 414                         pending_claim_requests: HashMap::new(),
 415                         claimable_outpoints: HashMap::new(),
 416                         onchain_events_waiting_threshold_conf: HashMap::new(),
 417
 418                         secp_ctx: Secp256k1::new(),
 419                         logger,
 420                 }
 421         }
 422
 423         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 424                 let mut tx_weight = 2; // count segwit flags
 425                 for inp in inputs {
 426                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 427                         tx_weight +=  match inp {
 428                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 429                                 &InputDescriptors::RevokedOfferedHTLC => {
 430                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 431                                 },
 432                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 433                                 &InputDescriptors::RevokedReceivedHTLC => {
 434                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 435                                 },
 436                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 437                                 &InputDescriptors::OfferedHTLC => {
 438                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 439                                 },
 440                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 441                                 &InputDescriptors::ReceivedHTLC => {
 442                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 443                                 },
 444                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 445                                 &InputDescriptors::RevokedOutput => {
 446                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 447                                 },
 448                         };
 449                 }
 450                 tx_weight
 451         }
 452
 453         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 454         /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
 455         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 456         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 457         /// frequency of the bump and so increase our bets of success.
 458         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 459                 if timelock_expiration <= current_height + 3 {
 460                         return current_height + 1
 461                 } else if timelock_expiration - current_height <= 15 {
 462                         return current_height + 3
 463                 }
 464                 current_height + 15
 465         }
 466
 467         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
 468         /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
 469         fn generate_claim_tx<F: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
 470                 where F::Target: FeeEstimator
 471         {
 472                 if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
 473                 let mut inputs = Vec::new();
 474                 for outp in cached_claim_datas.per_input_material.keys() {
 475                         log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
 476                         inputs.push(TxIn {
 477                                 previous_output: *outp,
 478                                 script_sig: Script::new(),
 479                                 sequence: 0xfffffffd,
 480                                 witness: Vec::new(),
 481                         });
 482                 }
 483                 let mut bumped_tx = Transaction {
 484                         version: 2,
 485                         lock_time: 0,
 486                         input: inputs,
 487                         output: vec![TxOut {
 488                                 script_pubkey: self.destination_script.clone(),
 489                                 value: 0
 490                         }],
 491                 };
 492
 493                 macro_rules! RBF_bump {
 494                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 495                                 {
 496                                         let mut used_feerate;
 497                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 498                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 499                                                 let mut value = $amount;
 500                                                 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
 501                                                         // Overflow check is done in subtract_high_prio_fee
 502                                                         $amount - value
 503                                                 } else {
 504                                                         log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 505                                                         return None;
 506                                                 }
 507                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 508                                         } else {
 509                                                 let fee = $old_feerate * $predicted_weight / 750;
 510                                                 if $amount <= fee {
 511                                                         log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 512                                                         return None;
 513                                                 }
 514                                                 fee
 515                                         };
 516
 517                                         let previous_fee = $old_feerate * $predicted_weight / 1000;
 518                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
 519                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 520                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 521                                         //      * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
 522                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 523                                                 new_fee + previous_fee + min_relay_fee - new_fee
 524                                         } else {
 525                                                 new_fee
 526                                         };
 527                                         Some((new_fee, new_fee * 1000 / $predicted_weight))
 528                                 }
 529                         }
 530                 }
 531
 532                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 533                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 534                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
 535                 let mut inputs_witnesses_weight = 0;
 536                 let mut amt = 0;
 537                 let mut dynamic_fee = true;
 538                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 539                         match per_outp_material {
 540                                 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
 541                                         inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
 542                                         amt += *amount;
 543                                 },
 544                                 &InputMaterial::RemoteHTLC { ref preimage, ref htlc, .. } => {
 545                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 546                                         amt += htlc.amount_msat / 1000;
 547                                 },
 548                                 &InputMaterial::LocalHTLC { .. } => {
 549                                         dynamic_fee = false;
 550                                 },
 551                                 &InputMaterial::Funding { .. } => {
 552                                         dynamic_fee = false;
 553                                 }
 554                         }
 555                 }
 556                 if dynamic_fee {
 557                         let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
 558                         let mut new_feerate;
 559                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
 560                         if cached_claim_datas.feerate_previous != 0 {
 561                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
 562                                         // If new computed fee is superior at the whole claimable amount burn all in fees
 563                                         if new_fee > amt {
 564                                                 bumped_tx.output[0].value = 0;
 565                                         } else {
 566                                                 bumped_tx.output[0].value = amt - new_fee;
 567                                         }
 568                                         new_feerate = feerate;
 569                                 } else { return None; }
 570                         } else {
 571                                 if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
 572                                         bumped_tx.output[0].value = amt;
 573                                 } else { return None; }
 574                         }
 575                         assert!(new_feerate != 0);
 576
 577                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 578                                 match per_outp_material {
 579                                         &InputMaterial::Revoked { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_remote_tx_csv } => {
 580                                                 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, remote_delayed_payment_base_key, remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
 581
 582                                                         let witness_script = if let Some(ref htlc) = *htlc {
 583                                                                 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key)
 584                                                         } else {
 585                                                                 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, *on_remote_tx_csv, &chan_keys.a_delayed_payment_key)
 586                                                         };
 587
 588                                                         if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, *on_remote_tx_csv, &self.secp_ctx) {
 589                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 590                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 591                                                                 if htlc.is_some() {
 592                                                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 593                                                                 } else {
 594                                                                         bumped_tx.input[i].witness.push(vec!(1));
 595                                                                 }
 596                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 597                                                         } else { return None; }
 598                                                         //TODO: panic ?
 599
 600                                                         log_trace!(self, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_local" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
 601                                                 }
 602                                         },
 603                                         &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc } => {
 604                                                 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, remote_delayed_payment_base_key, remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
 605                                                         let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key);
 606
 607                                                         if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
 608                                                         if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx) {
 609                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 610                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 611                                                                 if let &Some(preimage) = preimage {
 612                                                                         bumped_tx.input[i].witness.push(preimage.0.to_vec());
 613                                                                 } else {
 614                                                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 615                                                                         bumped_tx.input[i].witness.push(vec![]);
 616                                                                 }
 617                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 618                                                         }
 619                                                         log_trace!(self, "Going to broadcast Claim Transaction {} claiming remote {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
 620                                                 }
 621                                         },
 622                                         _ => unreachable!()
 623                                 }
 624                         }
 625                         log_trace!(self, "...with timer {}", new_timer.unwrap());
 626                         assert!(predicted_weight >= bumped_tx.get_weight());
 627                         return Some((new_timer, new_feerate, bumped_tx))
 628                 } else {
 629                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 630                                 match per_outp_material {
 631                                         &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
 632                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
 633                                                 if let Some(htlc_tx) = htlc_tx {
 634                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
 635                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
 636                                                         log_trace!(self, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
 637                                                         return Some((None, feerate, htlc_tx));
 638                                                 }
 639                                                 return None;
 640                                         },
 641                                         &InputMaterial::Funding { ref funding_redeemscript } => {
 642                                                 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
 643                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
 644                                                 log_trace!(self, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
 645                                                 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
 646                                         }
 647                                         _ => unreachable!()
 648                                 }
 649                         }
 650                 }
 651                 None
 652         }
 653
 654         pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F)
 655                 where B::Target: BroadcasterInterface,
 656                       F::Target: FeeEstimator
 657         {
 658                 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
 659                 let mut new_claims = Vec::new();
 660                 let mut aggregated_claim = HashMap::new();
 661                 let mut aggregated_soonest = ::std::u32::MAX;
 662
 663                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 664                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 665                 for req in claimable_outpoints {
 666                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 667                         if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
 668                                 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 669                                 if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable
 670                                         let mut single_input = HashMap::new();
 671                                         single_input.insert(req.outpoint, req.witness_data);
 672                                         new_claims.push((req.absolute_timelock, single_input));
 673                                 } else {
 674                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 675                                         if req.absolute_timelock < aggregated_soonest {
 676                                                 aggregated_soonest = req.absolute_timelock;
 677                                         }
 678                                 }
 679                         }
 680                 }
 681                 new_claims.push((aggregated_soonest, aggregated_claim));
 682
 683                 // Generate claim transactions and track them to bump if necessary at
 684                 // height timer expiration (i.e in how many blocks we're going to take action).
 685                 for (soonest_timelock, claim) in new_claims.drain(..) {
 686                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
 687                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 688                                 claim_material.height_timer = new_timer;
 689                                 claim_material.feerate_previous = new_feerate;
 690                                 let txid = tx.txid();
 691                                 for k in claim_material.per_input_material.keys() {
 692                                         log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
 693                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 694                                 }
 695                                 self.pending_claim_requests.insert(txid, claim_material);
 696                                 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
 697                                 broadcaster.broadcast_transaction(&tx);
 698                         }
 699                 }
 700
 701                 let mut bump_candidates = HashMap::new();
 702                 for tx in txn_matched {
 703                         // Scan all input to verify is one of the outpoint spent is of interest for us
 704                         let mut claimed_outputs_material = Vec::new();
 705                         for inp in &tx.input {
 706                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 707                                         // If outpoint has claim request pending on it...
 708                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 709                                                 //... we need to verify equality between transaction outpoints and claim request
 710                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 711                                                 // by us.
 712                                                 let mut set_equality = true;
 713                                                 if claim_material.per_input_material.len() != tx.input.len() {
 714                                                         set_equality = false;
 715                                                 } else {
 716                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 717                                                                 if *claim_inp != tx_inp.previous_output {
 718                                                                         set_equality = false;
 719                                                                 }
 720                                                         }
 721                                                 }
 722
 723                                                 macro_rules! clean_claim_request_after_safety_delay {
 724                                                         () => {
 725                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 726                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 727                                                                         hash_map::Entry::Occupied(mut entry) => {
 728                                                                                 if !entry.get().contains(&new_event) {
 729                                                                                         entry.get_mut().push(new_event);
 730                                                                                 }
 731                                                                         },
 732                                                                         hash_map::Entry::Vacant(entry) => {
 733                                                                                 entry.insert(vec![new_event]);
 734                                                                         }
 735                                                                 }
 736                                                         }
 737                                                 }
 738
 739                                                 // If this is our transaction (or our counterparty spent all the outputs
 740                                                 // before we could anyway with same inputs order than us), wait for
 741                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 742                                                 if set_equality {
 743                                                         clean_claim_request_after_safety_delay!();
 744                                                 } else { // If false, generate new claim request with update outpoint set
 745                                                         let mut at_least_one_drop = false;
 746                                                         for input in tx.input.iter() {
 747                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 748                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 749                                                                         at_least_one_drop = true;
 750                                                                 }
 751                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 752                                                                 if claim_material.per_input_material.is_empty() {
 753                                                                         clean_claim_request_after_safety_delay!();
 754                                                                 }
 755                                                         }
 756                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 757                                                         if at_least_one_drop {
 758                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
 759                                                         }
 760                                                 }
 761                                                 break; //No need to iterate further, either tx is our or their
 762                                         } else {
 763                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 764                                         }
 765                                 }
 766                         }
 767                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 768                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 769                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 770                                         hash_map::Entry::Occupied(mut entry) => {
 771                                                 if !entry.get().contains(&new_event) {
 772                                                         entry.get_mut().push(new_event);
 773                                                 }
 774                                         },
 775                                         hash_map::Entry::Vacant(entry) => {
 776                                                 entry.insert(vec![new_event]);
 777                                         }
 778                                 }
 779                         }
 780                 }
 781
 782                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 783                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 784                         for ev in events {
 785                                 match ev {
 786                                         OnchainEvent::Claim { claim_request } => {
 787                                                 // We may remove a whole set of claim outpoints here, as these one may have
 788                                                 // been aggregated in a single tx and claimed so atomically
 789                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 790                                                         for outpoint in bump_material.per_input_material.keys() {
 791                                                                 self.claimable_outpoints.remove(&outpoint);
 792                                                         }
 793                                                 }
 794                                         },
 795                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 796                                                 self.claimable_outpoints.remove(&outpoint);
 797                                         }
 798                                 }
 799                         }
 800                 }
 801
 802                 // Check if any pending claim request must be rescheduled
 803                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 804                         if let Some(h) = claim_data.height_timer {
 805                                 if h == height {
 806                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
 807                                 }
 808                         }
 809                 }
 810
 811                 // Build, bump and rebroadcast tx accordingly
 812                 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
 813                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
 814                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 815                                 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
 816                                 broadcaster.broadcast_transaction(&bump_tx);
 817                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 818                                         claim_material.height_timer = new_timer;
 819                                         claim_material.feerate_previous = new_feerate;
 820                                 }
 821                         }
 822                 }
 823         }
 824
 825         pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
 826                 where B::Target: BroadcasterInterface,
 827                       F::Target: FeeEstimator
 828         {
 829                 let mut bump_candidates = HashMap::new();
 830                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 831                         //- our claim tx on a commitment tx output
 832                         //- resurect outpoint back in its claimable set and regenerate tx
 833                         for ev in events {
 834                                 match ev {
 835                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 836                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 837                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 838                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 839                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 840                                                                 // resurrected only one bump claim tx is going to be broadcast
 841                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 842                                                         }
 843                                                 }
 844                                         },
 845                                         _ => {},
 846                                 }
 847                         }
 848                 }
 849                 for (_, claim_material) in bump_candidates.iter_mut() {
 850                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 851                                 claim_material.height_timer = new_timer;
 852                                 claim_material.feerate_previous = new_feerate;
 853                                 broadcaster.broadcast_transaction(&bump_tx);
 854                         }
 855                 }
 856                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 857                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 858                 }
 859                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 860                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 861                 let mut remove_request = Vec::new();
 862                 self.claimable_outpoints.retain(|_, ref v|
 863                         if v.1 == height {
 864                         remove_request.push(v.0.clone());
 865                         false
 866                         } else { true });
 867                 for req in remove_request {
 868                         self.pending_claim_requests.remove(&req);
 869                 }
 870         }
 871
 872         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
 873                 // To prevent any unsafe state discrepancy between offchain and onchain, once local
 874                 // commitment transaction has been signed due to an event (either block height for
 875                 // HTLC-timeout or channel force-closure), don't allow any further update of local
 876                 // commitment transaction view to avoid delivery of revocation secret to counterparty
 877                 // for the aformentionned signed transaction.
 878                 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
 879                         return Err(());
 880                 }
 881                 self.prev_local_commitment = self.local_commitment.take();
 882                 self.local_commitment = Some(tx);
 883                 Ok(())
 884         }
 885
 886         fn sign_latest_local_htlcs(&mut self) {
 887                 if let Some(ref local_commitment) = self.local_commitment {
 888                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.on_local_tx_csv, &self.secp_ctx) {
 889                                 self.local_htlc_sigs = Some(Vec::new());
 890                                 let ret = self.local_htlc_sigs.as_mut().unwrap();
 891                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 892                                         if let Some(tx_idx) = htlc.transaction_output_index {
 893                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 894                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 895                                         } else {
 896                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 897                                         }
 898                                 }
 899                         }
 900                 }
 901         }
 902         fn sign_prev_local_htlcs(&mut self) {
 903                 if let Some(ref local_commitment) = self.prev_local_commitment {
 904                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.on_local_tx_csv, &self.secp_ctx) {
 905                                 self.prev_local_htlc_sigs = Some(Vec::new());
 906                                 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
 907                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 908                                         if let Some(tx_idx) = htlc.transaction_output_index {
 909                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 910                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 911                                         } else {
 912                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 913                                         }
 914                                 }
 915                         }
 916                 }
 917         }
 918
 919         //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
 920         // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 921         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 922         // to monitor before.
 923         pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 924                 if let Some(ref mut local_commitment) = self.local_commitment {
 925                         match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
 926                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 927                                 Err(_) => return None,
 928                         }
 929                 } else {
 930                         None
 931                 }
 932         }
 933
 934         #[cfg(test)]
 935         pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 936                 if let Some(ref mut local_commitment) = self.local_commitment {
 937                         let local_commitment = local_commitment.clone();
 938                         match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
 939                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 940                                 Err(_) => return None,
 941                         }
 942                 } else {
 943                         None
 944                 }
 945         }
 946
 947         pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 948                 let mut htlc_tx = None;
 949                 if self.local_commitment.is_some() {
 950                         let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
 951                         if commitment_txid == outp.txid {
 952                                 self.sign_latest_local_htlcs();
 953                                 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
 954                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 955                                         htlc_tx = Some(self.local_commitment.as_ref().unwrap()
 956                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_local_tx_csv));
 957                                 }
 958                         }
 959                 }
 960                 if self.prev_local_commitment.is_some() {
 961                         let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
 962                         if commitment_txid == outp.txid {
 963                                 self.sign_prev_local_htlcs();
 964                                 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
 965                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 966                                         htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
 967                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_local_tx_csv));
 968                                 }
 969                         }
 970                 }
 971                 htlc_tx
 972         }
 973
 974         #[cfg(test)]
 975         pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 976                 let latest_had_sigs = self.local_htlc_sigs.is_some();
 977                 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
 978                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
 979                 if !latest_had_sigs {
 980                         self.local_htlc_sigs = None;
 981                 }
 982                 if !prev_had_sigs {
 983                         self.prev_local_htlc_sigs = None;
 984                 }
 985                 ret
 986         }
 987 }