_ Git - rust-lightning/blob - lightning/src/chain/package.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Various utilities to assemble claimable outpoints in package of one or more transactions. Those
  11 //! packages are attached metadata, guiding their aggregable or fee-bumping re-schedule. This file
  12 //! also includes witness weight computation and fee computation methods.
  13
  14 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
  15 use bitcoin::blockdata::transaction::{TxOut,TxIn, Transaction, EcdsaSighashType};
  16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  17 use bitcoin::blockdata::script::Script;
  18
  19 use bitcoin::hash_types::Txid;
  20
  21 use bitcoin::secp256k1::{SecretKey,PublicKey};
  22
  23 use crate::ln::PaymentPreimage;
  24 use crate::ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment};
  25 use crate::ln::chan_utils;
  26 use crate::ln::msgs::DecodeError;
  27 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  28 use crate::chain::keysinterface::WriteableEcdsaChannelSigner;
  29 #[cfg(anchors)]
  30 use crate::chain::onchaintx::ExternalHTLCClaim;
  31 use crate::chain::onchaintx::OnchainTxHandler;
  32 use crate::util::logger::Logger;
  33 use crate::util::ser::{Readable, Writer, Writeable};
  34
  35 use crate::io;
  36 use crate::prelude::*;
  37 use core::cmp;
  38 #[cfg(anchors)]
  39 use core::convert::TryInto;
  40 use core::mem;
  41 use core::ops::Deref;
  42 use bitcoin::{PackedLockTime, Sequence, Witness};
  43
  44 use super::chaininterface::LowerBoundedFeeEstimator;
  45
  46 const MAX_ALLOC_SIZE: usize = 64*1024;
  47
  48
  49 pub(crate) fn weight_revoked_offered_htlc(opt_anchors: bool) -> u64 {
  50         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  51         const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
  52         const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  53         if opt_anchors { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
  54 }
  55
  56 pub(crate) fn weight_revoked_received_htlc(opt_anchors: bool) -> u64 {
  57         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  58         const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 +  139;
  59         const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  60         if opt_anchors { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
  61 }
  62
  63 pub(crate) fn weight_offered_htlc(opt_anchors: bool) -> u64 {
  64         // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
  65         const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
  66         const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  67         if opt_anchors { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
  68 }
  69
  70 pub(crate) fn weight_received_htlc(opt_anchors: bool) -> u64 {
  71         // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
  72         const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
  73         const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  74         if opt_anchors { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
  75 }
  76
  77 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
  78 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
  79
  80 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
  81 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
  82 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
  83 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
  84 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
  85 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
  86
  87 /// A struct to describe a revoked output and corresponding information to generate a solving
  88 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
  89 ///
  90 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
  91 /// as part of the signature hash and revocation secret to generate a satisfying witness.
  92 #[derive(Clone, PartialEq, Eq)]
  93 pub(crate) struct RevokedOutput {
  94         per_commitment_point: PublicKey,
  95         counterparty_delayed_payment_base_key: PublicKey,
  96         counterparty_htlc_base_key: PublicKey,
  97         per_commitment_key: SecretKey,
  98         weight: u64,
  99         amount: u64,
 100         on_counterparty_tx_csv: u16,
 101 }
 102
 103 impl RevokedOutput {
 104         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, on_counterparty_tx_csv: u16) -> Self {
 105                 RevokedOutput {
 106                         per_commitment_point,
 107                         counterparty_delayed_payment_base_key,
 108                         counterparty_htlc_base_key,
 109                         per_commitment_key,
 110                         weight: WEIGHT_REVOKED_OUTPUT,
 111                         amount,
 112                         on_counterparty_tx_csv
 113                 }
 114         }
 115 }
 116
 117 impl_writeable_tlv_based!(RevokedOutput, {
 118         (0, per_commitment_point, required),
 119         (2, counterparty_delayed_payment_base_key, required),
 120         (4, counterparty_htlc_base_key, required),
 121         (6, per_commitment_key, required),
 122         (8, weight, required),
 123         (10, amount, required),
 124         (12, on_counterparty_tx_csv, required),
 125 });
 126
 127 /// A struct to describe a revoked offered output and corresponding information to generate a
 128 /// solving witness.
 129 ///
 130 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
 131 /// witnessScript.
 132 ///
 133 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
 134 /// of the signature hash and revocation secret to generate a satisfying witness.
 135 #[derive(Clone, PartialEq, Eq)]
 136 pub(crate) struct RevokedHTLCOutput {
 137         per_commitment_point: PublicKey,
 138         counterparty_delayed_payment_base_key: PublicKey,
 139         counterparty_htlc_base_key: PublicKey,
 140         per_commitment_key: SecretKey,
 141         weight: u64,
 142         amount: u64,
 143         htlc: HTLCOutputInCommitment,
 144 }
 145
 146 impl RevokedHTLCOutput {
 147         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 148                 let weight = if htlc.offered { weight_revoked_offered_htlc(opt_anchors) } else { weight_revoked_received_htlc(opt_anchors) };
 149                 RevokedHTLCOutput {
 150                         per_commitment_point,
 151                         counterparty_delayed_payment_base_key,
 152                         counterparty_htlc_base_key,
 153                         per_commitment_key,
 154                         weight,
 155                         amount,
 156                         htlc
 157                 }
 158         }
 159 }
 160
 161 impl_writeable_tlv_based!(RevokedHTLCOutput, {
 162         (0, per_commitment_point, required),
 163         (2, counterparty_delayed_payment_base_key, required),
 164         (4, counterparty_htlc_base_key, required),
 165         (6, per_commitment_key, required),
 166         (8, weight, required),
 167         (10, amount, required),
 168         (12, htlc, required),
 169 });
 170
 171 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 172 ///
 173 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 174 /// witnessScript.
 175 ///
 176 /// The preimage is used as part of the witness.
 177 #[derive(Clone, PartialEq, Eq)]
 178 pub(crate) struct CounterpartyOfferedHTLCOutput {
 179         per_commitment_point: PublicKey,
 180         counterparty_delayed_payment_base_key: PublicKey,
 181         counterparty_htlc_base_key: PublicKey,
 182         preimage: PaymentPreimage,
 183         htlc: HTLCOutputInCommitment,
 184         opt_anchors: Option<()>,
 185 }
 186
 187 impl CounterpartyOfferedHTLCOutput {
 188         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 189                 CounterpartyOfferedHTLCOutput {
 190                         per_commitment_point,
 191                         counterparty_delayed_payment_base_key,
 192                         counterparty_htlc_base_key,
 193                         preimage,
 194                         htlc,
 195                         opt_anchors: if opt_anchors { Some(()) } else { None },
 196                 }
 197         }
 198
 199         fn opt_anchors(&self) -> bool {
 200                 self.opt_anchors.is_some()
 201         }
 202 }
 203
 204 impl_writeable_tlv_based!(CounterpartyOfferedHTLCOutput, {
 205         (0, per_commitment_point, required),
 206         (2, counterparty_delayed_payment_base_key, required),
 207         (4, counterparty_htlc_base_key, required),
 208         (6, preimage, required),
 209         (8, htlc, required),
 210         (10, opt_anchors, option),
 211 });
 212
 213 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 214 ///
 215 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 216 /// witnessScript.
 217 #[derive(Clone, PartialEq, Eq)]
 218 pub(crate) struct CounterpartyReceivedHTLCOutput {
 219         per_commitment_point: PublicKey,
 220         counterparty_delayed_payment_base_key: PublicKey,
 221         counterparty_htlc_base_key: PublicKey,
 222         htlc: HTLCOutputInCommitment,
 223         opt_anchors: Option<()>,
 224 }
 225
 226 impl CounterpartyReceivedHTLCOutput {
 227         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 228                 CounterpartyReceivedHTLCOutput {
 229                         per_commitment_point,
 230                         counterparty_delayed_payment_base_key,
 231                         counterparty_htlc_base_key,
 232                         htlc,
 233                         opt_anchors: if opt_anchors { Some(()) } else { None },
 234                 }
 235         }
 236
 237         fn opt_anchors(&self) -> bool {
 238                 self.opt_anchors.is_some()
 239         }
 240 }
 241
 242 impl_writeable_tlv_based!(CounterpartyReceivedHTLCOutput, {
 243         (0, per_commitment_point, required),
 244         (2, counterparty_delayed_payment_base_key, required),
 245         (4, counterparty_htlc_base_key, required),
 246         (6, htlc, required),
 247         (8, opt_anchors, option),
 248 });
 249
 250 /// A struct to describe a HTLC output on holder commitment transaction.
 251 ///
 252 /// Either offered or received, the amount is always used as part of the bip143 sighash.
 253 /// Preimage is only included as part of the witness in former case.
 254 #[derive(Clone, PartialEq, Eq)]
 255 pub(crate) struct HolderHTLCOutput {
 256         preimage: Option<PaymentPreimage>,
 257         amount_msat: u64,
 258         /// Defaults to 0 for HTLC-Success transactions, which have no expiry
 259         cltv_expiry: u32,
 260         opt_anchors: Option<()>,
 261 }
 262
 263 impl HolderHTLCOutput {
 264         pub(crate) fn build_offered(amount_msat: u64, cltv_expiry: u32, opt_anchors: bool) -> Self {
 265                 HolderHTLCOutput {
 266                         preimage: None,
 267                         amount_msat,
 268                         cltv_expiry,
 269                         opt_anchors: if opt_anchors { Some(()) } else { None } ,
 270                 }
 271         }
 272
 273         pub(crate) fn build_accepted(preimage: PaymentPreimage, amount_msat: u64, opt_anchors: bool) -> Self {
 274                 HolderHTLCOutput {
 275                         preimage: Some(preimage),
 276                         amount_msat,
 277                         cltv_expiry: 0,
 278                         opt_anchors: if opt_anchors { Some(()) } else { None } ,
 279                 }
 280         }
 281
 282         fn opt_anchors(&self) -> bool {
 283                 self.opt_anchors.is_some()
 284         }
 285 }
 286
 287 impl_writeable_tlv_based!(HolderHTLCOutput, {
 288         (0, amount_msat, required),
 289         (2, cltv_expiry, required),
 290         (4, preimage, option),
 291         (6, opt_anchors, option)
 292 });
 293
 294 /// A struct to describe the channel output on the funding transaction.
 295 ///
 296 /// witnessScript is used as part of the witness redeeming the funding utxo.
 297 #[derive(Clone, PartialEq, Eq)]
 298 pub(crate) struct HolderFundingOutput {
 299         funding_redeemscript: Script,
 300         funding_amount: Option<u64>,
 301         opt_anchors: Option<()>,
 302 }
 303
 304
 305 impl HolderFundingOutput {
 306         pub(crate) fn build(funding_redeemscript: Script, funding_amount: u64, opt_anchors: bool) -> Self {
 307                 HolderFundingOutput {
 308                         funding_redeemscript,
 309                         funding_amount: Some(funding_amount),
 310                         opt_anchors: if opt_anchors { Some(()) } else { None },
 311                 }
 312         }
 313
 314         fn opt_anchors(&self) -> bool {
 315                 self.opt_anchors.is_some()
 316         }
 317 }
 318
 319 impl_writeable_tlv_based!(HolderFundingOutput, {
 320         (0, funding_redeemscript, required),
 321         (2, opt_anchors, option),
 322         (3, funding_amount, option),
 323 });
 324
 325 /// A wrapper encapsulating all in-protocol differing outputs types.
 326 ///
 327 /// The generic API offers access to an outputs common attributes or allow transformation such as
 328 /// finalizing an input claiming the output.
 329 #[derive(Clone, PartialEq, Eq)]
 330 pub(crate) enum PackageSolvingData {
 331         RevokedOutput(RevokedOutput),
 332         RevokedHTLCOutput(RevokedHTLCOutput),
 333         CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
 334         CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
 335         HolderHTLCOutput(HolderHTLCOutput),
 336         HolderFundingOutput(HolderFundingOutput),
 337 }
 338
 339 impl PackageSolvingData {
 340         fn amount(&self) -> u64 {
 341                 let amt = match self {
 342                         PackageSolvingData::RevokedOutput(ref outp) => outp.amount,
 343                         PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
 344                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 345                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 346                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 347                                 debug_assert!(outp.opt_anchors());
 348                                 outp.amount_msat / 1000
 349                         },
 350                         PackageSolvingData::HolderFundingOutput(ref outp) => {
 351                                 debug_assert!(outp.opt_anchors());
 352                                 outp.funding_amount.unwrap()
 353                         }
 354                 };
 355                 amt
 356         }
 357         fn weight(&self) -> usize {
 358                 match self {
 359                         PackageSolvingData::RevokedOutput(ref outp) => outp.weight as usize,
 360                         PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.weight as usize,
 361                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => weight_offered_htlc(outp.opt_anchors()) as usize,
 362                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => weight_received_htlc(outp.opt_anchors()) as usize,
 363                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 364                                 debug_assert!(outp.opt_anchors());
 365                                 if outp.preimage.is_none() {
 366                                         weight_offered_htlc(true) as usize
 367                                 } else {
 368                                         weight_received_htlc(true) as usize
 369                                 }
 370                         },
 371                         // Since HolderFundingOutput maps to an untractable package that is already signed, its
 372                         // weight can be determined from the transaction itself.
 373                         PackageSolvingData::HolderFundingOutput(..) => unreachable!(),
 374                 }
 375         }
 376         fn is_compatible(&self, input: &PackageSolvingData) -> bool {
 377                 match self {
 378                         PackageSolvingData::RevokedOutput(..) => {
 379                                 match input {
 380                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 381                                         PackageSolvingData::RevokedOutput(..) => { true },
 382                                         _ => { false }
 383                                 }
 384                         },
 385                         PackageSolvingData::RevokedHTLCOutput(..) => {
 386                                 match input {
 387                                         PackageSolvingData::RevokedOutput(..) => { true },
 388                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 389                                         _ => { false }
 390                                 }
 391                         },
 392                         _ => { mem::discriminant(self) == mem::discriminant(&input) }
 393                 }
 394         }
 395         fn finalize_input<Signer: WriteableEcdsaChannelSigner>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
 396                 match self {
 397                         PackageSolvingData::RevokedOutput(ref outp) => {
 398                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 399                                 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
 400                                 //TODO: should we panic on signer failure ?
 401                                 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
 402                                         let mut ser_sig = sig.serialize_der().to_vec();
 403                                         ser_sig.push(EcdsaSighashType::All as u8);
 404                                         bumped_tx.input[i].witness.push(ser_sig);
 405                                         bumped_tx.input[i].witness.push(vec!(1));
 406                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 407                                 } else { return false; }
 408                         },
 409                         PackageSolvingData::RevokedHTLCOutput(ref outp) => {
 410                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 411                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 412                                 //TODO: should we panic on signer failure ?
 413                                 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_htlc(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &outp.htlc, &onchain_handler.secp_ctx) {
 414                                         let mut ser_sig = sig.serialize_der().to_vec();
 415                                         ser_sig.push(EcdsaSighashType::All as u8);
 416                                         bumped_tx.input[i].witness.push(ser_sig);
 417                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 418                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 419                                 } else { return false; }
 420                         },
 421                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
 422                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 423                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 424
 425                                 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
 426                                         let mut ser_sig = sig.serialize_der().to_vec();
 427                                         ser_sig.push(EcdsaSighashType::All as u8);
 428                                         bumped_tx.input[i].witness.push(ser_sig);
 429                                         bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
 430                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 431                                 }
 432                         },
 433                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
 434                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 435                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 436
 437                                 bumped_tx.lock_time = PackedLockTime(outp.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
 438                                 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
 439                                         let mut ser_sig = sig.serialize_der().to_vec();
 440                                         ser_sig.push(EcdsaSighashType::All as u8);
 441                                         bumped_tx.input[i].witness.push(ser_sig);
 442                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 443                                         bumped_tx.input[i].witness.push(vec![]);
 444                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 445                                 }
 446                         },
 447                         _ => { panic!("API Error!"); }
 448                 }
 449                 true
 450         }
 451         fn get_finalized_tx<Signer: WriteableEcdsaChannelSigner>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
 452                 match self {
 453                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 454                                 debug_assert!(!outp.opt_anchors());
 455                                 return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage);
 456                         }
 457                         PackageSolvingData::HolderFundingOutput(ref outp) => {
 458                                 return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript));
 459                         }
 460                         _ => { panic!("API Error!"); }
 461                 }
 462         }
 463         fn absolute_tx_timelock(&self, current_height: u32) -> u32 {
 464                 // We use `current_height + 1` as our default locktime to discourage fee sniping and because
 465                 // transactions with it always propagate.
 466                 let absolute_timelock = match self {
 467                         PackageSolvingData::RevokedOutput(_) => current_height + 1,
 468                         PackageSolvingData::RevokedHTLCOutput(_) => current_height + 1,
 469                         PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => current_height + 1,
 470                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, current_height + 1),
 471                         // HTLC timeout/success transactions rely on a fixed timelock due to the counterparty's
 472                         // signature.
 473                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 474                                 if outp.preimage.is_some() {
 475                                         debug_assert_eq!(outp.cltv_expiry, 0);
 476                                 }
 477                                 outp.cltv_expiry
 478                         },
 479                         PackageSolvingData::HolderFundingOutput(_) => current_height + 1,
 480                 };
 481                 absolute_timelock
 482         }
 483 }
 484
 485 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
 486         (0, RevokedOutput),
 487         (1, RevokedHTLCOutput),
 488         (2, CounterpartyOfferedHTLCOutput),
 489         (3, CounterpartyReceivedHTLCOutput),
 490         (4, HolderHTLCOutput),
 491         (5, HolderFundingOutput),
 492 );
 493
 494 /// A malleable package might be aggregated with other packages to save on fees.
 495 /// A untractable package has been counter-signed and aggregable will break cached counterparty
 496 /// signatures.
 497 #[derive(Clone, PartialEq, Eq)]
 498 pub(crate) enum PackageMalleability {
 499         Malleable,
 500         Untractable,
 501 }
 502
 503 /// A structure to describe a package content that is generated by ChannelMonitor and
 504 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
 505 ///
 506 /// A package is defined as one or more transactions claiming onchain outputs in reaction
 507 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
 508 /// fees, if satisfaction of outputs's witnessScript let's us do so.
 509 ///
 510 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
 511 /// Failing to confirm a package translate as a loss of funds for the user.
 512 #[derive(Clone, PartialEq, Eq)]
 513 pub struct PackageTemplate {
 514         // List of onchain outputs and solving data to generate satisfying witnesses.
 515         inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
 516         // Packages are deemed as malleable if we have local knwoledge of at least one set of
 517         // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
 518         // packages among them to save on fees or rely on RBF to bump their feerates.
 519         // Untractable packages have been counter-signed and thus imply that we can't aggregate
 520         // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
 521         malleability: PackageMalleability,
 522         // Block height after which the earlier-output belonging to this package is mature for a
 523         // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
 524         // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
 525         soonest_conf_deadline: u32,
 526         // Determines if this package can be aggregated.
 527         // Timelocked outputs belonging to the same transaction might have differing
 528         // satisfying heights. Picking up the later height among the output set would be a valid
 529         // aggregable strategy but it comes with at least 2 trade-offs :
 530         // * earlier-output fund are going to take longer to come back
 531         // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
 532         // by the requirement of the later-output part of the set
 533         // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
 534         // smarter aggregable strategy in the future.
 535         aggregable: bool,
 536         // Cache of package feerate committed at previous (re)broadcast. If bumping resources
 537         // (either claimed output value or external utxo), it will keep increasing until holder
 538         // or counterparty successful claim.
 539         feerate_previous: u64,
 540         // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
 541         // the future, we might abstract it to an observed mempool fluctuation.
 542         height_timer: Option<u32>,
 543         // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
 544         // it, we wipe out and forget the package.
 545         height_original: u32,
 546 }
 547
 548 impl PackageTemplate {
 549         pub(crate) fn is_malleable(&self) -> bool {
 550                 self.malleability == PackageMalleability::Malleable
 551         }
 552         pub(crate) fn timelock(&self) -> u32 {
 553                 self.soonest_conf_deadline
 554         }
 555         pub(crate) fn aggregable(&self) -> bool {
 556                 self.aggregable
 557         }
 558         pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
 559                 self.feerate_previous = new_feerate;
 560         }
 561         pub(crate) fn timer(&self) -> Option<u32> {
 562                 if let Some(ref timer) = self.height_timer {
 563                         return Some(*timer);
 564                 }
 565                 None
 566         }
 567         pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
 568                 self.height_timer = new_timer;
 569         }
 570         pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
 571                 self.inputs.iter().map(|(o, _)| o).collect()
 572         }
 573         pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
 574                 self.inputs.iter().map(|(_, i)| i)
 575         }
 576         pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
 577                 match self.malleability {
 578                         PackageMalleability::Malleable => {
 579                                 let mut split_package = None;
 580                                 let timelock = self.soonest_conf_deadline;
 581                                 let aggregable = self.aggregable;
 582                                 let feerate_previous = self.feerate_previous;
 583                                 let height_timer = self.height_timer;
 584                                 let height_original = self.height_original;
 585                                 self.inputs.retain(|outp| {
 586                                         if *split_outp == outp.0 {
 587                                                 split_package = Some(PackageTemplate {
 588                                                         inputs: vec![(outp.0, outp.1.clone())],
 589                                                         malleability: PackageMalleability::Malleable,
 590                                                         soonest_conf_deadline: timelock,
 591                                                         aggregable,
 592                                                         feerate_previous,
 593                                                         height_timer,
 594                                                         height_original,
 595                                                 });
 596                                                 return false;
 597                                         }
 598                                         return true;
 599                                 });
 600                                 return split_package;
 601                         },
 602                         _ => {
 603                                 // Note, we may try to split on remote transaction for
 604                                 // which we don't have a competing one (HTLC-Success before
 605                                 // timelock expiration). This explain we don't panic!
 606                                 // We should refactor OnchainTxHandler::block_connected to
 607                                 // only test equality on competing claims.
 608                                 return None;
 609                         }
 610                 }
 611         }
 612         pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
 613                 assert_eq!(self.height_original, merge_from.height_original);
 614                 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
 615                         panic!("Merging template on untractable packages");
 616                 }
 617                 if !self.aggregable || !merge_from.aggregable {
 618                         panic!("Merging non aggregatable packages");
 619                 }
 620                 if let Some((_, lead_input)) = self.inputs.first() {
 621                         for (_, v) in merge_from.inputs.iter() {
 622                                 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
 623                         }
 624                 } else { panic!("Merging template on an empty package"); }
 625                 for (k, v) in merge_from.inputs.drain(..) {
 626                         self.inputs.push((k, v));
 627                 }
 628                 //TODO: verify coverage and sanity?
 629                 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
 630                         self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
 631                 }
 632                 if self.feerate_previous > merge_from.feerate_previous {
 633                         self.feerate_previous = merge_from.feerate_previous;
 634                 }
 635                 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
 636         }
 637         /// Gets the amount of all outptus being spent by this package, only valid for malleable
 638         /// packages.
 639         pub(crate) fn package_amount(&self) -> u64 {
 640                 let mut amounts = 0;
 641                 for (_, outp) in self.inputs.iter() {
 642                         amounts += outp.amount();
 643                 }
 644                 amounts
 645         }
 646         pub(crate) fn package_locktime(&self, current_height: u32) -> u32 {
 647                 let locktime = self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(current_height))
 648                         .max().expect("There must always be at least one output to spend in a PackageTemplate");
 649
 650                 // If we ever try to aggregate a `HolderHTLCOutput`s with another output type, we'll likely
 651                 // end up with an incorrect transaction locktime since the counterparty has included it in
 652                 // its HTLC signature. This should never happen unless we decide to aggregate outputs across
 653                 // different channel commitments.
 654                 #[cfg(debug_assertions)] {
 655                         if self.inputs.iter().any(|(_, outp)|
 656                                 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
 657                                         outp.preimage.is_some()
 658                                 } else {
 659                                         false
 660                                 }
 661                         ) {
 662                                 debug_assert_eq!(locktime, 0);
 663                         };
 664                         for timeout_htlc_expiry in self.inputs.iter().filter_map(|(_, outp)|
 665                                 if let PackageSolvingData::HolderHTLCOutput(outp) = outp {
 666                                         if outp.preimage.is_none() {
 667                                                 Some(outp.cltv_expiry)
 668                                         } else { None }
 669                                 } else { None }
 670                         ) {
 671                                 debug_assert_eq!(locktime, timeout_htlc_expiry);
 672                         }
 673                 }
 674
 675                 locktime
 676         }
 677         pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
 678                 let mut inputs_weight = 0;
 679                 let mut witnesses_weight = 2; // count segwit flags
 680                 for (_, outp) in self.inputs.iter() {
 681                         // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
 682                         inputs_weight += 41 * WITNESS_SCALE_FACTOR;
 683                         witnesses_weight += outp.weight();
 684                 }
 685                 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
 686                 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
 687                 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
 688                 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
 689                 inputs_weight + witnesses_weight + transaction_weight + output_weight
 690         }
 691         #[cfg(anchors)]
 692         pub(crate) fn construct_malleable_package_with_external_funding<Signer: WriteableEcdsaChannelSigner>(
 693                 &self, onchain_handler: &mut OnchainTxHandler<Signer>,
 694         ) -> Option<Vec<ExternalHTLCClaim>> {
 695                 debug_assert!(self.requires_external_funding());
 696                 let mut htlcs: Option<Vec<ExternalHTLCClaim>> = None;
 697                 for (previous_output, input) in &self.inputs {
 698                         match input {
 699                                 PackageSolvingData::HolderHTLCOutput(ref outp) => {
 700                                         debug_assert!(outp.opt_anchors());
 701                                         onchain_handler.generate_external_htlc_claim(&previous_output, &outp.preimage).map(|htlc| {
 702                                                 htlcs.get_or_insert_with(|| Vec::with_capacity(self.inputs.len())).push(htlc);
 703                                         });
 704                                 }
 705                                 _ => debug_assert!(false, "Expected HolderHTLCOutputs to not be aggregated with other input types"),
 706                         }
 707                 }
 708                 htlcs
 709         }
 710         pub(crate) fn finalize_malleable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
 711                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L
 712         ) -> Option<Transaction> where L::Target: Logger {
 713                 debug_assert!(self.is_malleable());
 714                 let mut bumped_tx = Transaction {
 715                         version: 2,
 716                         lock_time: PackedLockTime::ZERO,
 717                         input: vec![],
 718                         output: vec![TxOut {
 719                                 script_pubkey: destination_script,
 720                                 value,
 721                         }],
 722                 };
 723                 for (outpoint, _) in self.inputs.iter() {
 724                         bumped_tx.input.push(TxIn {
 725                                 previous_output: *outpoint,
 726                                 script_sig: Script::new(),
 727                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 728                                 witness: Witness::new(),
 729                         });
 730                 }
 731                 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
 732                         log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 733                         if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
 734                 }
 735                 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
 736                 Some(bumped_tx)
 737         }
 738         pub(crate) fn finalize_untractable_package<L: Deref, Signer: WriteableEcdsaChannelSigner>(
 739                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
 740         ) -> Option<Transaction> where L::Target: Logger {
 741                 debug_assert!(!self.is_malleable());
 742                 if let Some((outpoint, outp)) = self.inputs.first() {
 743                         if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
 744                                 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 745                                 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
 746                                 return Some(final_tx);
 747                         }
 748                         return None;
 749                 } else { panic!("API Error: Package must not be inputs empty"); }
 750         }
 751         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 752         /// 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
 753         /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
 754         /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
 755         /// frequency of the bump and so increase our bets of success.
 756         pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
 757                 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
 758                         return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
 759                 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
 760                         return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
 761                 }
 762                 current_height + LOW_FREQUENCY_BUMP_INTERVAL
 763         }
 764
 765         /// Returns value in satoshis to be included as package outgoing output amount and feerate
 766         /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
 767         /// value.
 768         pub(crate) fn compute_package_output<F: Deref, L: Deref>(&self, predicted_weight: usize, dust_limit_sats: u64, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 769                 where F::Target: FeeEstimator,
 770                       L::Target: Logger,
 771         {
 772                 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
 773                 let input_amounts = self.package_amount();
 774                 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
 775                 // If old feerate is 0, first iteration of this claim, use normal fee calculation
 776                 if self.feerate_previous != 0 {
 777                         if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, self.feerate_previous, fee_estimator, logger) {
 778                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 779                         }
 780                 } else {
 781                         if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 782                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 783                         }
 784                 }
 785                 None
 786         }
 787
 788         #[cfg(anchors)]
 789         /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
 790         /// and the new feerate is below it, we'll use a 25% increase of the previous feerate instead of
 791         /// the new one.
 792         pub(crate) fn compute_package_feerate<F: Deref>(
 793                 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
 794         ) -> u32 where F::Target: FeeEstimator {
 795                 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
 796                 if self.feerate_previous != 0 {
 797                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 798                         if feerate_estimate as u64 > self.feerate_previous {
 799                                 feerate_estimate
 800                         } else {
 801                                 // ...else just increase the previous feerate by 25% (because that's a nice number)
 802                                 (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
 803                         }
 804                 } else {
 805                         feerate_estimate
 806                 }
 807         }
 808
 809         /// Determines whether a package contains an input which must have additional external inputs
 810         /// attached to help the spending transaction reach confirmation.
 811         pub(crate) fn requires_external_funding(&self) -> bool {
 812                 self.inputs.iter().find(|input| match input.1 {
 813                         PackageSolvingData::HolderFundingOutput(ref outp) => outp.opt_anchors(),
 814                         PackageSolvingData::HolderHTLCOutput(ref outp) => outp.opt_anchors(),
 815                         _ => false,
 816                 }).is_some()
 817         }
 818
 819         pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
 820                 let malleability = match input_solving_data {
 821                         PackageSolvingData::RevokedOutput(..) => PackageMalleability::Malleable,
 822                         PackageSolvingData::RevokedHTLCOutput(..) => PackageMalleability::Malleable,
 823                         PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => PackageMalleability::Malleable,
 824                         PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => PackageMalleability::Malleable,
 825                         PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.opt_anchors() {
 826                                 PackageMalleability::Malleable
 827                         } else {
 828                                 PackageMalleability::Untractable
 829                         },
 830                         PackageSolvingData::HolderFundingOutput(..) => PackageMalleability::Untractable,
 831                 };
 832                 let mut inputs = Vec::with_capacity(1);
 833                 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
 834                 PackageTemplate {
 835                         inputs,
 836                         malleability,
 837                         soonest_conf_deadline,
 838                         aggregable,
 839                         feerate_previous: 0,
 840                         height_timer: None,
 841                         height_original,
 842                 }
 843         }
 844 }
 845
 846 impl Writeable for PackageTemplate {
 847         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 848                 writer.write_all(&(self.inputs.len() as u64).to_be_bytes())?;
 849                 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
 850                         outpoint.write(writer)?;
 851                         rev_outp.write(writer)?;
 852                 }
 853                 write_tlv_fields!(writer, {
 854                         (0, self.soonest_conf_deadline, required),
 855                         (2, self.feerate_previous, required),
 856                         (4, self.height_original, required),
 857                         (6, self.height_timer, option)
 858                 });
 859                 Ok(())
 860         }
 861 }
 862
 863 impl Readable for PackageTemplate {
 864         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 865                 let inputs_count = <u64 as Readable>::read(reader)?;
 866                 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
 867                 for _ in 0..inputs_count {
 868                         let outpoint = Readable::read(reader)?;
 869                         let rev_outp = Readable::read(reader)?;
 870                         inputs.push((outpoint, rev_outp));
 871                 }
 872                 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
 873                         match lead_input {
 874                                 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
 875                                 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 876                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 877                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
 878                                 PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.opt_anchors() {
 879                                         (PackageMalleability::Malleable, outp.preimage.is_some())
 880                                 } else {
 881                                         (PackageMalleability::Untractable, false)
 882                                 },
 883                                 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
 884                         }
 885                 } else { return Err(DecodeError::InvalidValue); };
 886                 let mut soonest_conf_deadline = 0;
 887                 let mut feerate_previous = 0;
 888                 let mut height_timer = None;
 889                 let mut height_original = 0;
 890                 read_tlv_fields!(reader, {
 891                         (0, soonest_conf_deadline, required),
 892                         (2, feerate_previous, required),
 893                         (4, height_original, required),
 894                         (6, height_timer, option),
 895                 });
 896                 Ok(PackageTemplate {
 897                         inputs,
 898                         malleability,
 899                         soonest_conf_deadline,
 900                         aggregable,
 901                         feerate_previous,
 902                         height_timer,
 903                         height_original,
 904                 })
 905         }
 906 }
 907
 908 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 909 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
 910 /// fall-back to lower priorities until we have enough value available to suck from.
 911 ///
 912 /// If the proposed fee is less than the available spent output's values, we return the proposed
 913 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
 914 /// available spent output's values, we return nothing
 915 fn compute_fee_from_spent_amounts<F: Deref, L: Deref>(input_amounts: u64, predicted_weight: usize, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 916         where F::Target: FeeEstimator,
 917               L::Target: Logger,
 918 {
 919         let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
 920         let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
 921         if input_amounts <= fee {
 922                 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
 923                 fee = updated_feerate * (predicted_weight as u64) / 1000;
 924                 if input_amounts <= fee {
 925                         updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
 926                         fee = updated_feerate * (predicted_weight as u64) / 1000;
 927                         if input_amounts <= fee {
 928                                 log_error!(logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 929                                         fee, input_amounts);
 930                                 None
 931                         } else {
 932                                 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 933                                         input_amounts);
 934                                 Some((fee, updated_feerate))
 935                         }
 936                 } else {
 937                         log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 938                                 input_amounts);
 939                         Some((fee, updated_feerate))
 940                 }
 941         } else {
 942                 Some((fee, updated_feerate))
 943         }
 944 }
 945
 946 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 947 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
 948 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
 949 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
 950 /// the new fee to meet the RBF policy requirement.
 951 fn feerate_bump<F: Deref, L: Deref>(predicted_weight: usize, input_amounts: u64, previous_feerate: u64, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 952         where F::Target: FeeEstimator,
 953               L::Target: Logger,
 954 {
 955         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 956         let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 957                 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
 958                 if updated_feerate > previous_feerate {
 959                         new_fee
 960                 } else {
 961                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 962                         let new_fee = previous_feerate * (predicted_weight as u64) / 750;
 963                         if input_amounts <= new_fee {
 964                                 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
 965                                 return None;
 966                         }
 967                         new_fee
 968                 }
 969         } else {
 970                 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
 971                 return None;
 972         };
 973
 974         let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
 975         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
 976         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 977         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 978         //      * 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.
 979         let new_fee = if new_fee < previous_fee + min_relay_fee {
 980                 new_fee + previous_fee + min_relay_fee - new_fee
 981         } else {
 982                 new_fee
 983         };
 984         Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
 985 }
 986
 987 #[cfg(test)]
 988 mod tests {
 989         use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
 990         use crate::chain::Txid;
 991         use crate::ln::chan_utils::HTLCOutputInCommitment;
 992         use crate::ln::{PaymentPreimage, PaymentHash};
 993
 994         use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
 995         use bitcoin::blockdata::script::Script;
 996         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 997
 998         use bitcoin::hashes::hex::FromHex;
 999
1000         use bitcoin::secp256k1::{PublicKey,SecretKey};
1001         use bitcoin::secp256k1::Secp256k1;
1002
1003         macro_rules! dumb_revk_output {
1004                 ($secp_ctx: expr) => {
1005                         {
1006                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1007                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1008                                 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0))
1009                         }
1010                 }
1011         }
1012
1013         macro_rules! dumb_counterparty_output {
1014                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1015                         {
1016                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1017                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1018                                 let hash = PaymentHash([1; 32]);
1019                                 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
1020                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
1021                         }
1022                 }
1023         }
1024
1025         macro_rules! dumb_counterparty_offered_output {
1026                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
1027                         {
1028                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
1029                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
1030                                 let hash = PaymentHash([1; 32]);
1031                                 let preimage = PaymentPreimage([2;32]);
1032                                 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
1033                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
1034                         }
1035                 }
1036         }
1037
1038         macro_rules! dumb_htlc_output {
1039                 () => {
1040                         {
1041                                 let preimage = PaymentPreimage([2;32]);
1042                                 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0, false))
1043                         }
1044                 }
1045         }
1046
1047         #[test]
1048         #[should_panic]
1049         fn test_package_differing_heights() {
1050                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1051                 let secp_ctx = Secp256k1::new();
1052                 let revk_outp = dumb_revk_output!(secp_ctx);
1053
1054                 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1055                 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 200);
1056                 package_one_hundred.merge_package(package_two_hundred);
1057         }
1058
1059         #[test]
1060         #[should_panic]
1061         fn test_package_untractable_merge_to() {
1062                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1063                 let secp_ctx = Secp256k1::new();
1064                 let revk_outp = dumb_revk_output!(secp_ctx);
1065                 let htlc_outp = dumb_htlc_output!();
1066
1067                 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1068                 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, true, 100);
1069                 untractable_package.merge_package(malleable_package);
1070         }
1071
1072         #[test]
1073         #[should_panic]
1074         fn test_package_untractable_merge_from() {
1075                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1076                 let secp_ctx = Secp256k1::new();
1077                 let htlc_outp = dumb_htlc_output!();
1078                 let revk_outp = dumb_revk_output!(secp_ctx);
1079
1080                 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, true, 100);
1081                 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1082                 malleable_package.merge_package(untractable_package);
1083         }
1084
1085         #[test]
1086         #[should_panic]
1087         fn test_package_noaggregation_to() {
1088                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1089                 let secp_ctx = Secp256k1::new();
1090                 let revk_outp = dumb_revk_output!(secp_ctx);
1091
1092                 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, false, 100);
1093                 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1094                 noaggregation_package.merge_package(aggregation_package);
1095         }
1096
1097         #[test]
1098         #[should_panic]
1099         fn test_package_noaggregation_from() {
1100                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1101                 let secp_ctx = Secp256k1::new();
1102                 let revk_outp = dumb_revk_output!(secp_ctx);
1103
1104                 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1105                 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, false, 100);
1106                 aggregation_package.merge_package(noaggregation_package);
1107         }
1108
1109         #[test]
1110         #[should_panic]
1111         fn test_package_empty() {
1112                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1113                 let secp_ctx = Secp256k1::new();
1114                 let revk_outp = dumb_revk_output!(secp_ctx);
1115
1116                 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1117                 empty_package.inputs = vec![];
1118                 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1119                 empty_package.merge_package(package);
1120         }
1121
1122         #[test]
1123         #[should_panic]
1124         fn test_package_differing_categories() {
1125                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1126                 let secp_ctx = Secp256k1::new();
1127                 let revk_outp = dumb_revk_output!(secp_ctx);
1128                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, false);
1129
1130                 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1131                 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, true, 100);
1132                 revoked_package.merge_package(counterparty_package);
1133         }
1134
1135         #[test]
1136         fn test_package_split_malleable() {
1137                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1138                 let secp_ctx = Secp256k1::new();
1139                 let revk_outp_one = dumb_revk_output!(secp_ctx);
1140                 let revk_outp_two = dumb_revk_output!(secp_ctx);
1141                 let revk_outp_three = dumb_revk_output!(secp_ctx);
1142
1143                 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, true, 100);
1144                 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, true, 100);
1145                 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, true, 100);
1146
1147                 package_one.merge_package(package_two);
1148                 package_one.merge_package(package_three);
1149                 assert_eq!(package_one.outpoints().len(), 3);
1150
1151                 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1152                         // Packages attributes should be identical
1153                         assert!(split_package.is_malleable());
1154                         assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1155                         assert_eq!(split_package.aggregable, package_one.aggregable);
1156                         assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1157                         assert_eq!(split_package.height_timer, package_one.height_timer);
1158                         assert_eq!(split_package.height_original, package_one.height_original);
1159                 } else { panic!(); }
1160                 assert_eq!(package_one.outpoints().len(), 2);
1161         }
1162
1163         #[test]
1164         fn test_package_split_untractable() {
1165                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1166                 let htlc_outp_one = dumb_htlc_output!();
1167
1168                 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, true, 100);
1169                 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1170                 assert!(ret_split.is_none());
1171         }
1172
1173         #[test]
1174         fn test_package_timer() {
1175                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1176                 let secp_ctx = Secp256k1::new();
1177                 let revk_outp = dumb_revk_output!(secp_ctx);
1178
1179                 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1180                 let timer_none = package.timer();
1181                 assert!(timer_none.is_none());
1182                 package.set_timer(Some(100));
1183                 if let Some(timer_some) = package.timer() {
1184                         assert_eq!(timer_some, 100);
1185                 } else { panic!() }
1186         }
1187
1188         #[test]
1189         fn test_package_amounts() {
1190                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1191                 let secp_ctx = Secp256k1::new();
1192                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, false);
1193
1194                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1195                 assert_eq!(package.package_amount(), 1000);
1196         }
1197
1198         #[test]
1199         fn test_package_weight() {
1200                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1201                 let secp_ctx = Secp256k1::new();
1202
1203                 // (nVersion (4) + nLocktime (4) + count_tx_in (1) + prevout (36) + sequence (4) + script_length (1) + count_tx_out (1) + value (8) + var_int (1)) * WITNESS_SCALE_FACTOR + witness marker (2)
1204                 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1205
1206                 {
1207                         let revk_outp = dumb_revk_output!(secp_ctx);
1208                         let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, true, 100);
1209                         assert_eq!(package.package_weight(&Script::new()),  weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1210                 }
1211
1212                 {
1213                         for &opt_anchors in [false, true].iter() {
1214                                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, opt_anchors);
1215                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1216                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(opt_anchors) as usize);
1217                         }
1218                 }
1219
1220                 {
1221                         for &opt_anchors in [false, true].iter() {
1222                                 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, opt_anchors);
1223                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1224                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(opt_anchors) as usize);
1225                         }
1226                 }
1227         }
1228 }