_ Git - rust-lightning/blob - lightning/src/ln/chan_utils.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 for building scripts and deriving keys related to channels. These are
  11 //! largely of interest for those implementing chain::keysinterface::Sign message signing by hand.
  12
  13 use bitcoin::blockdata::script::{Script,Builder};
  14 use bitcoin::blockdata::opcodes;
  15 use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, SigHashType};
  16 use bitcoin::util::bip143;
  17
  18 use bitcoin::hashes::{Hash, HashEngine};
  19 use bitcoin::hashes::sha256::Hash as Sha256;
  20 use bitcoin::hashes::ripemd160::Hash as Ripemd160;
  21 use bitcoin::hash_types::{Txid, PubkeyHash};
  22
  23 use ln::{PaymentHash, PaymentPreimage};
  24 use ln::msgs::DecodeError;
  25 use util::ser::{Readable, Writeable, Writer};
  26 use util::{byte_utils, transaction_utils};
  27
  28 use bitcoin::hash_types::WPubkeyHash;
  29 use bitcoin::secp256k1::key::{SecretKey, PublicKey};
  30 use bitcoin::secp256k1::{Secp256k1, Signature, Message};
  31 use bitcoin::secp256k1::Error as SecpError;
  32 use bitcoin::secp256k1;
  33
  34 use io;
  35 use prelude::*;
  36 use core::cmp;
  37 use ln::chan_utils;
  38 use util::transaction_utils::sort_outputs;
  39 use ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI};
  40 use core::ops::Deref;
  41 use chain;
  42
  43 pub(crate) const MAX_HTLCS: u16 = 483;
  44
  45 pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
  46 pub(super) const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
  47
  48 #[derive(PartialEq)]
  49 pub(crate) enum HTLCType {
  50         AcceptedHTLC,
  51         OfferedHTLC
  52 }
  53
  54 impl HTLCType {
  55         /// Check if a given tx witnessScript len matchs one of a pre-signed HTLC
  56         pub(crate) fn scriptlen_to_htlctype(witness_script_len: usize) ->  Option<HTLCType> {
  57                 if witness_script_len == 133 {
  58                         Some(HTLCType::OfferedHTLC)
  59                 } else if witness_script_len >= 136 && witness_script_len <= 139 {
  60                         Some(HTLCType::AcceptedHTLC)
  61                 } else {
  62                         None
  63                 }
  64         }
  65 }
  66
  67 // Various functions for key derivation and transaction creation for use within channels. Primarily
  68 // used in Channel and ChannelMonitor.
  69
  70 /// Build the commitment secret from the seed and the commitment number
  71 pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] {
  72         let mut res: [u8; 32] = commitment_seed.clone();
  73         for i in 0..48 {
  74                 let bitpos = 47 - i;
  75                 if idx & (1 << bitpos) == (1 << bitpos) {
  76                         res[bitpos / 8] ^= 1 << (bitpos & 7);
  77                         res = Sha256::hash(&res).into_inner();
  78                 }
  79         }
  80         res
  81 }
  82
  83 /// Build a closing transaction
  84 pub fn build_closing_transaction(value_to_holder: u64, value_to_counterparty: u64, holder_shutdown_script: Script, counterparty_shutdown_script: Script, funding_outpoint: OutPoint) -> Transaction {
  85         let txins = {
  86                 let mut ins: Vec<TxIn> = Vec::new();
  87                 ins.push(TxIn {
  88                         previous_output: funding_outpoint,
  89                         script_sig: Script::new(),
  90                         sequence: 0xffffffff,
  91                         witness: Vec::new(),
  92                 });
  93                 ins
  94         };
  95
  96         let mut txouts: Vec<(TxOut, ())> = Vec::new();
  97
  98         if value_to_counterparty > 0 {
  99                 txouts.push((TxOut {
 100                         script_pubkey: counterparty_shutdown_script,
 101                         value: value_to_counterparty
 102                 }, ()));
 103         }
 104
 105         if value_to_holder > 0 {
 106                 txouts.push((TxOut {
 107                         script_pubkey: holder_shutdown_script,
 108                         value: value_to_holder
 109                 }, ()));
 110         }
 111
 112         transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
 113
 114         let mut outputs: Vec<TxOut> = Vec::new();
 115         for out in txouts.drain(..) {
 116                 outputs.push(out.0);
 117         }
 118
 119         Transaction {
 120                 version: 2,
 121                 lock_time: 0,
 122                 input: txins,
 123                 output: outputs,
 124         }
 125 }
 126
 127 /// Implements the per-commitment secret storage scheme from
 128 /// [BOLT 3](https://github.com/lightningnetwork/lightning-rfc/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
 129 ///
 130 /// Allows us to keep track of all of the revocation secrets of counterarties in just 50*32 bytes
 131 /// or so.
 132 #[derive(Clone)]
 133 pub(crate) struct CounterpartyCommitmentSecrets {
 134         old_secrets: [([u8; 32], u64); 49],
 135 }
 136
 137 impl PartialEq for CounterpartyCommitmentSecrets {
 138         fn eq(&self, other: &Self) -> bool {
 139                 for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
 140                         if secret != o_secret || idx != o_idx {
 141                                 return false
 142                         }
 143                 }
 144                 true
 145         }
 146 }
 147
 148 impl CounterpartyCommitmentSecrets {
 149         pub(crate) fn new() -> Self {
 150                 Self { old_secrets: [([0; 32], 1 << 48); 49], }
 151         }
 152
 153         #[inline]
 154         fn place_secret(idx: u64) -> u8 {
 155                 for i in 0..48 {
 156                         if idx & (1 << i) == (1 << i) {
 157                                 return i
 158                         }
 159                 }
 160                 48
 161         }
 162
 163         pub(crate) fn get_min_seen_secret(&self) -> u64 {
 164                 //TODO This can be optimized?
 165                 let mut min = 1 << 48;
 166                 for &(_, idx) in self.old_secrets.iter() {
 167                         if idx < min {
 168                                 min = idx;
 169                         }
 170                 }
 171                 min
 172         }
 173
 174         #[inline]
 175         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
 176                 let mut res: [u8; 32] = secret;
 177                 for i in 0..bits {
 178                         let bitpos = bits - 1 - i;
 179                         if idx & (1 << bitpos) == (1 << bitpos) {
 180                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
 181                                 res = Sha256::hash(&res).into_inner();
 182                         }
 183                 }
 184                 res
 185         }
 186
 187         pub(crate) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
 188                 let pos = Self::place_secret(idx);
 189                 for i in 0..pos {
 190                         let (old_secret, old_idx) = self.old_secrets[i as usize];
 191                         if Self::derive_secret(secret, pos, old_idx) != old_secret {
 192                                 return Err(());
 193                         }
 194                 }
 195                 if self.get_min_seen_secret() <= idx {
 196                         return Ok(());
 197                 }
 198                 self.old_secrets[pos as usize] = (secret, idx);
 199                 Ok(())
 200         }
 201
 202         /// Can only fail if idx is < get_min_seen_secret
 203         pub(crate) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
 204                 for i in 0..self.old_secrets.len() {
 205                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
 206                                 return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
 207                         }
 208                 }
 209                 assert!(idx < self.get_min_seen_secret());
 210                 None
 211         }
 212 }
 213
 214 impl Writeable for CounterpartyCommitmentSecrets {
 215         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 216                 for &(ref secret, ref idx) in self.old_secrets.iter() {
 217                         writer.write_all(secret)?;
 218                         writer.write_all(&byte_utils::be64_to_array(*idx))?;
 219                 }
 220                 write_tlv_fields!(writer, {});
 221                 Ok(())
 222         }
 223 }
 224 impl Readable for CounterpartyCommitmentSecrets {
 225         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 226                 let mut old_secrets = [([0; 32], 1 << 48); 49];
 227                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
 228                         *secret = Readable::read(reader)?;
 229                         *idx = Readable::read(reader)?;
 230                 }
 231                 read_tlv_fields!(reader, {});
 232                 Ok(Self { old_secrets })
 233         }
 234 }
 235
 236 /// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
 237 /// from the base secret and the per_commitment_point.
 238 ///
 239 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
 240 /// generated (ie our own).
 241 pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, SecpError> {
 242         let mut sha = Sha256::engine();
 243         sha.input(&per_commitment_point.serialize());
 244         sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
 245         let res = Sha256::from_engine(sha).into_inner();
 246
 247         let mut key = base_secret.clone();
 248         key.add_assign(&res)?;
 249         Ok(key)
 250 }
 251
 252 /// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
 253 /// from the base point and the per_commitment_key. This is the public equivalent of
 254 /// derive_private_key - using only public keys to derive a public key instead of private keys.
 255 ///
 256 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
 257 /// generated (ie our own).
 258 pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, SecpError> {
 259         let mut sha = Sha256::engine();
 260         sha.input(&per_commitment_point.serialize());
 261         sha.input(&base_point.serialize());
 262         let res = Sha256::from_engine(sha).into_inner();
 263
 264         let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&res)?);
 265         base_point.combine(&hashkey)
 266 }
 267
 268 /// Derives a per-commitment-transaction revocation key from its constituent parts.
 269 ///
 270 /// Only the cheating participant owns a valid witness to propagate a revoked
 271 /// commitment transaction, thus per_commitment_secret always come from cheater
 272 /// and revocation_base_secret always come from punisher, which is the broadcaster
 273 /// of the transaction spending with this key knowledge.
 274 ///
 275 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
 276 /// generated (ie our own).
 277 pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey) -> Result<SecretKey, SecpError> {
 278         let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret);
 279         let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
 280
 281         let rev_append_commit_hash_key = {
 282                 let mut sha = Sha256::engine();
 283                 sha.input(&countersignatory_revocation_base_point.serialize());
 284                 sha.input(&per_commitment_point.serialize());
 285
 286                 Sha256::from_engine(sha).into_inner()
 287         };
 288         let commit_append_rev_hash_key = {
 289                 let mut sha = Sha256::engine();
 290                 sha.input(&per_commitment_point.serialize());
 291                 sha.input(&countersignatory_revocation_base_point.serialize());
 292
 293                 Sha256::from_engine(sha).into_inner()
 294         };
 295
 296         let mut countersignatory_contrib = countersignatory_revocation_base_secret.clone();
 297         countersignatory_contrib.mul_assign(&rev_append_commit_hash_key)?;
 298         let mut broadcaster_contrib = per_commitment_secret.clone();
 299         broadcaster_contrib.mul_assign(&commit_append_rev_hash_key)?;
 300         countersignatory_contrib.add_assign(&broadcaster_contrib[..])?;
 301         Ok(countersignatory_contrib)
 302 }
 303
 304 /// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
 305 /// the public equivalend of derive_private_revocation_key - using only public keys to derive a
 306 /// public key instead of private keys.
 307 ///
 308 /// Only the cheating participant owns a valid witness to propagate a revoked
 309 /// commitment transaction, thus per_commitment_point always come from cheater
 310 /// and revocation_base_point always come from punisher, which is the broadcaster
 311 /// of the transaction spending with this key knowledge.
 312 ///
 313 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
 314 /// generated (ie our own).
 315 pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey) -> Result<PublicKey, SecpError> {
 316         let rev_append_commit_hash_key = {
 317                 let mut sha = Sha256::engine();
 318                 sha.input(&countersignatory_revocation_base_point.serialize());
 319                 sha.input(&per_commitment_point.serialize());
 320
 321                 Sha256::from_engine(sha).into_inner()
 322         };
 323         let commit_append_rev_hash_key = {
 324                 let mut sha = Sha256::engine();
 325                 sha.input(&per_commitment_point.serialize());
 326                 sha.input(&countersignatory_revocation_base_point.serialize());
 327
 328                 Sha256::from_engine(sha).into_inner()
 329         };
 330
 331         let mut countersignatory_contrib = countersignatory_revocation_base_point.clone();
 332         countersignatory_contrib.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?;
 333         let mut broadcaster_contrib = per_commitment_point.clone();
 334         broadcaster_contrib.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?;
 335         countersignatory_contrib.combine(&broadcaster_contrib)
 336 }
 337
 338 /// The set of public keys which are used in the creation of one commitment transaction.
 339 /// These are derived from the channel base keys and per-commitment data.
 340 ///
 341 /// A broadcaster key is provided from potential broadcaster of the computed transaction.
 342 /// A countersignatory key is coming from a protocol participant unable to broadcast the
 343 /// transaction.
 344 ///
 345 /// These keys are assumed to be good, either because the code derived them from
 346 /// channel basepoints via the new function, or they were obtained via
 347 /// CommitmentTransaction.trust().keys() because we trusted the source of the
 348 /// pre-calculated keys.
 349 #[derive(PartialEq, Clone)]
 350 pub struct TxCreationKeys {
 351         /// The broadcaster's per-commitment public key which was used to derive the other keys.
 352         pub per_commitment_point: PublicKey,
 353         /// The revocation key which is used to allow the broadcaster of the commitment
 354         /// transaction to provide their counterparty the ability to punish them if they broadcast
 355         /// an old state.
 356         pub revocation_key: PublicKey,
 357         /// Broadcaster's HTLC Key
 358         pub broadcaster_htlc_key: PublicKey,
 359         /// Countersignatory's HTLC Key
 360         pub countersignatory_htlc_key: PublicKey,
 361         /// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay)
 362         pub broadcaster_delayed_payment_key: PublicKey,
 363 }
 364
 365 impl_writeable_tlv_based!(TxCreationKeys, {
 366         (0, per_commitment_point, required),
 367         (2, revocation_key, required),
 368         (4, broadcaster_htlc_key, required),
 369         (6, countersignatory_htlc_key, required),
 370         (8, broadcaster_delayed_payment_key, required),
 371 });
 372
 373 /// One counterparty's public keys which do not change over the life of a channel.
 374 #[derive(Clone, PartialEq)]
 375 pub struct ChannelPublicKeys {
 376         /// The public key which is used to sign all commitment transactions, as it appears in the
 377         /// on-chain channel lock-in 2-of-2 multisig output.
 378         pub funding_pubkey: PublicKey,
 379         /// The base point which is used (with derive_public_revocation_key) to derive per-commitment
 380         /// revocation keys. This is combined with the per-commitment-secret generated by the
 381         /// counterparty to create a secret which the counterparty can reveal to revoke previous
 382         /// states.
 383         pub revocation_basepoint: PublicKey,
 384         /// The public key on which the non-broadcaster (ie the countersignatory) receives an immediately
 385         /// spendable primary channel balance on the broadcaster's commitment transaction. This key is
 386         /// static across every commitment transaction.
 387         pub payment_point: PublicKey,
 388         /// The base point which is used (with derive_public_key) to derive a per-commitment payment
 389         /// public key which receives non-HTLC-encumbered funds which are only available for spending
 390         /// after some delay (or can be claimed via the revocation path).
 391         pub delayed_payment_basepoint: PublicKey,
 392         /// The base point which is used (with derive_public_key) to derive a per-commitment public key
 393         /// which is used to encumber HTLC-in-flight outputs.
 394         pub htlc_basepoint: PublicKey,
 395 }
 396
 397 impl_writeable_tlv_based!(ChannelPublicKeys, {
 398         (0, funding_pubkey, required),
 399         (2, revocation_basepoint, required),
 400         (4, payment_point, required),
 401         (6, delayed_payment_basepoint, required),
 402         (8, htlc_basepoint, required),
 403 });
 404
 405 impl TxCreationKeys {
 406         /// Create per-state keys from channel base points and the per-commitment point.
 407         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
 408         pub fn derive_new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, broadcaster_delayed_payment_base: &PublicKey, broadcaster_htlc_base: &PublicKey, countersignatory_revocation_base: &PublicKey, countersignatory_htlc_base: &PublicKey) -> Result<TxCreationKeys, SecpError> {
 409                 Ok(TxCreationKeys {
 410                         per_commitment_point: per_commitment_point.clone(),
 411                         revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base)?,
 412                         broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base)?,
 413                         countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base)?,
 414                         broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base)?,
 415                 })
 416         }
 417
 418         /// Generate per-state keys from channel static keys.
 419         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
 420         pub fn from_channel_static_keys<T: secp256k1::Signing + secp256k1::Verification>(per_commitment_point: &PublicKey, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TxCreationKeys, SecpError> {
 421                 TxCreationKeys::derive_new(
 422                         &secp_ctx,
 423                         &per_commitment_point,
 424                         &broadcaster_keys.delayed_payment_basepoint,
 425                         &broadcaster_keys.htlc_basepoint,
 426                         &countersignatory_keys.revocation_basepoint,
 427                         &countersignatory_keys.htlc_basepoint,
 428                 )
 429         }
 430 }
 431
 432 /// The maximum length of a script returned by get_revokeable_redeemscript.
 433 // Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public
 434 // keys of 33 bytes (+ 1 push).
 435 pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2;
 436
 437 /// A script either spendable by the revocation
 438 /// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
 439 /// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions.
 440 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> Script {
 441         let res = Builder::new().push_opcode(opcodes::all::OP_IF)
 442                       .push_slice(&revocation_key.serialize())
 443                       .push_opcode(opcodes::all::OP_ELSE)
 444                       .push_int(contest_delay as i64)
 445                       .push_opcode(opcodes::all::OP_CSV)
 446                       .push_opcode(opcodes::all::OP_DROP)
 447                       .push_slice(&broadcaster_delayed_payment_key.serialize())
 448                       .push_opcode(opcodes::all::OP_ENDIF)
 449                       .push_opcode(opcodes::all::OP_CHECKSIG)
 450                       .into_script();
 451         debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH);
 452         res
 453 }
 454
 455 #[derive(Clone, PartialEq)]
 456 /// Information about an HTLC as it appears in a commitment transaction
 457 pub struct HTLCOutputInCommitment {
 458         /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
 459         /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
 460         /// need to compare this value to whether the commitment transaction in question is that of
 461         /// the counterparty or our own.
 462         pub offered: bool,
 463         /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is
 464         /// this divided by 1000.
 465         pub amount_msat: u64,
 466         /// The CLTV lock-time at which this HTLC expires.
 467         pub cltv_expiry: u32,
 468         /// The hash of the preimage which unlocks this HTLC.
 469         pub payment_hash: PaymentHash,
 470         /// The position within the commitment transactions' outputs. This may be None if the value is
 471         /// below the dust limit (in which case no output appears in the commitment transaction and the
 472         /// value is spent to additional transaction fees).
 473         pub transaction_output_index: Option<u32>,
 474 }
 475
 476 impl_writeable_tlv_based!(HTLCOutputInCommitment, {
 477         (0, offered, required),
 478         (2, amount_msat, required),
 479         (4, cltv_expiry, required),
 480         (6, payment_hash, required),
 481         (8, transaction_output_index, option),
 482 });
 483
 484 #[inline]
 485 pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script {
 486         let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner();
 487         if htlc.offered {
 488                 Builder::new().push_opcode(opcodes::all::OP_DUP)
 489                               .push_opcode(opcodes::all::OP_HASH160)
 490                               .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
 491                               .push_opcode(opcodes::all::OP_EQUAL)
 492                               .push_opcode(opcodes::all::OP_IF)
 493                               .push_opcode(opcodes::all::OP_CHECKSIG)
 494                               .push_opcode(opcodes::all::OP_ELSE)
 495                               .push_slice(&countersignatory_htlc_key.serialize()[..])
 496                               .push_opcode(opcodes::all::OP_SWAP)
 497                               .push_opcode(opcodes::all::OP_SIZE)
 498                               .push_int(32)
 499                               .push_opcode(opcodes::all::OP_EQUAL)
 500                               .push_opcode(opcodes::all::OP_NOTIF)
 501                               .push_opcode(opcodes::all::OP_DROP)
 502                               .push_int(2)
 503                               .push_opcode(opcodes::all::OP_SWAP)
 504                               .push_slice(&broadcaster_htlc_key.serialize()[..])
 505                               .push_int(2)
 506                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
 507                               .push_opcode(opcodes::all::OP_ELSE)
 508                               .push_opcode(opcodes::all::OP_HASH160)
 509                               .push_slice(&payment_hash160)
 510                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
 511                               .push_opcode(opcodes::all::OP_CHECKSIG)
 512                               .push_opcode(opcodes::all::OP_ENDIF)
 513                               .push_opcode(opcodes::all::OP_ENDIF)
 514                               .into_script()
 515         } else {
 516                 Builder::new().push_opcode(opcodes::all::OP_DUP)
 517                               .push_opcode(opcodes::all::OP_HASH160)
 518                               .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
 519                               .push_opcode(opcodes::all::OP_EQUAL)
 520                               .push_opcode(opcodes::all::OP_IF)
 521                               .push_opcode(opcodes::all::OP_CHECKSIG)
 522                               .push_opcode(opcodes::all::OP_ELSE)
 523                               .push_slice(&countersignatory_htlc_key.serialize()[..])
 524                               .push_opcode(opcodes::all::OP_SWAP)
 525                               .push_opcode(opcodes::all::OP_SIZE)
 526                               .push_int(32)
 527                               .push_opcode(opcodes::all::OP_EQUAL)
 528                               .push_opcode(opcodes::all::OP_IF)
 529                               .push_opcode(opcodes::all::OP_HASH160)
 530                               .push_slice(&payment_hash160)
 531                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
 532                               .push_int(2)
 533                               .push_opcode(opcodes::all::OP_SWAP)
 534                               .push_slice(&broadcaster_htlc_key.serialize()[..])
 535                               .push_int(2)
 536                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
 537                               .push_opcode(opcodes::all::OP_ELSE)
 538                               .push_opcode(opcodes::all::OP_DROP)
 539                               .push_int(htlc.cltv_expiry as i64)
 540                               .push_opcode(opcodes::all::OP_CLTV)
 541                               .push_opcode(opcodes::all::OP_DROP)
 542                               .push_opcode(opcodes::all::OP_CHECKSIG)
 543                               .push_opcode(opcodes::all::OP_ENDIF)
 544                               .push_opcode(opcodes::all::OP_ENDIF)
 545                               .into_script()
 546         }
 547 }
 548
 549 /// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc
 550 /// does not need to have its previous_output_index filled.
 551 #[inline]
 552 pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Script {
 553         get_htlc_redeemscript_with_explicit_keys(htlc, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key)
 554 }
 555
 556 /// Gets the redeemscript for a funding output from the two funding public keys.
 557 /// Note that the order of funding public keys does not matter.
 558 pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &PublicKey) -> Script {
 559         let broadcaster_funding_key = broadcaster.serialize();
 560         let countersignatory_funding_key = countersignatory.serialize();
 561
 562         let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
 563         if broadcaster_funding_key[..] < countersignatory_funding_key[..] {
 564                 builder.push_slice(&broadcaster_funding_key)
 565                         .push_slice(&countersignatory_funding_key)
 566         } else {
 567                 builder.push_slice(&countersignatory_funding_key)
 568                         .push_slice(&broadcaster_funding_key)
 569         }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
 570 }
 571
 572 /// Builds an unsigned HTLC-Success or HTLC-Timeout transaction from the given channel and HTLC
 573 /// parameters. This is used by [`TrustedCommitmentTransaction::get_htlc_sigs`] to fetch the
 574 /// transaction which needs signing, and can be used to construct an HTLC transaction which is
 575 /// broadcastable given a counterparty HTLC signature.
 576 ///
 577 /// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the
 578 /// commitment transaction).
 579 pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
 580         let mut txins: Vec<TxIn> = Vec::new();
 581         txins.push(TxIn {
 582                 previous_output: OutPoint {
 583                         txid: commitment_txid.clone(),
 584                         vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
 585                 },
 586                 script_sig: Script::new(),
 587                 sequence: 0,
 588                 witness: Vec::new(),
 589         });
 590
 591         let total_fee = if htlc.offered {
 592                         feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000
 593                 } else {
 594                         feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000
 595                 };
 596
 597         let mut txouts: Vec<TxOut> = Vec::new();
 598         txouts.push(TxOut {
 599                 script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
 600                 value: htlc.amount_msat / 1000 - total_fee //TODO: BOLT 3 does not specify if we should add amount_msat before dividing or if we should divide by 1000 before subtracting (as we do here)
 601         });
 602
 603         Transaction {
 604                 version: 2,
 605                 lock_time: if htlc.offered { htlc.cltv_expiry } else { 0 },
 606                 input: txins,
 607                 output: txouts,
 608         }
 609 }
 610
 611 /// Gets the witnessScript for an anchor output from the funding public key.
 612 /// The witness in the spending input must be:
 613 /// <BIP 143 funding_signature>
 614 /// After 16 blocks of confirmation, an alternative satisfying witness could be:
 615 /// <>
 616 /// (empty vector required to satisfy compliance with MINIMALIF-standard rule)
 617 #[inline]
 618 pub(crate) fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script {
 619         Builder::new().push_slice(&funding_pubkey.serialize()[..])
 620                 .push_opcode(opcodes::all::OP_CHECKSIG)
 621                 .push_opcode(opcodes::all::OP_IFDUP)
 622                 .push_opcode(opcodes::all::OP_NOTIF)
 623                 .push_int(16)
 624                 .push_opcode(opcodes::all::OP_CSV)
 625                 .push_opcode(opcodes::all::OP_ENDIF)
 626                 .into_script()
 627 }
 628
 629 /// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
 630 /// The fields are organized by holder/counterparty.
 631 ///
 632 /// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters
 633 /// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions.
 634 #[derive(Clone)]
 635 pub struct ChannelTransactionParameters {
 636         /// Holder public keys
 637         pub holder_pubkeys: ChannelPublicKeys,
 638         /// The contest delay selected by the holder, which applies to counterparty-broadcast transactions
 639         pub holder_selected_contest_delay: u16,
 640         /// Whether the holder is the initiator of this channel.
 641         /// This is an input to the commitment number obscure factor computation.
 642         pub is_outbound_from_holder: bool,
 643         /// The late-bound counterparty channel transaction parameters.
 644         /// These parameters are populated at the point in the protocol where the counterparty provides them.
 645         pub counterparty_parameters: Option<CounterpartyChannelTransactionParameters>,
 646         /// The late-bound funding outpoint
 647         pub funding_outpoint: Option<chain::transaction::OutPoint>,
 648 }
 649
 650 /// Late-bound per-channel counterparty data used to build transactions.
 651 #[derive(Clone)]
 652 pub struct CounterpartyChannelTransactionParameters {
 653         /// Counter-party public keys
 654         pub pubkeys: ChannelPublicKeys,
 655         /// The contest delay selected by the counterparty, which applies to holder-broadcast transactions
 656         pub selected_contest_delay: u16,
 657 }
 658
 659 impl ChannelTransactionParameters {
 660         /// Whether the late bound parameters are populated.
 661         pub fn is_populated(&self) -> bool {
 662                 self.counterparty_parameters.is_some() && self.funding_outpoint.is_some()
 663         }
 664
 665         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
 666         /// given that the holder is the broadcaster.
 667         ///
 668         /// self.is_populated() must be true before calling this function.
 669         pub fn as_holder_broadcastable(&self) -> DirectedChannelTransactionParameters {
 670                 assert!(self.is_populated(), "self.late_parameters must be set before using as_holder_broadcastable");
 671                 DirectedChannelTransactionParameters {
 672                         inner: self,
 673                         holder_is_broadcaster: true
 674                 }
 675         }
 676
 677         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
 678         /// given that the counterparty is the broadcaster.
 679         ///
 680         /// self.is_populated() must be true before calling this function.
 681         pub fn as_counterparty_broadcastable(&self) -> DirectedChannelTransactionParameters {
 682                 assert!(self.is_populated(), "self.late_parameters must be set before using as_counterparty_broadcastable");
 683                 DirectedChannelTransactionParameters {
 684                         inner: self,
 685                         holder_is_broadcaster: false
 686                 }
 687         }
 688 }
 689
 690 impl_writeable_tlv_based!(CounterpartyChannelTransactionParameters, {
 691         (0, pubkeys, required),
 692         (2, selected_contest_delay, required),
 693 });
 694
 695 impl_writeable_tlv_based!(ChannelTransactionParameters, {
 696         (0, holder_pubkeys, required),
 697         (2, holder_selected_contest_delay, required),
 698         (4, is_outbound_from_holder, required),
 699         (6, counterparty_parameters, option),
 700         (8, funding_outpoint, option),
 701 });
 702
 703 /// Static channel fields used to build transactions given per-commitment fields, organized by
 704 /// broadcaster/countersignatory.
 705 ///
 706 /// This is derived from the holder/counterparty-organized ChannelTransactionParameters via the
 707 /// as_holder_broadcastable and as_counterparty_broadcastable functions.
 708 pub struct DirectedChannelTransactionParameters<'a> {
 709         /// The holder's channel static parameters
 710         inner: &'a ChannelTransactionParameters,
 711         /// Whether the holder is the broadcaster
 712         holder_is_broadcaster: bool,
 713 }
 714
 715 impl<'a> DirectedChannelTransactionParameters<'a> {
 716         /// Get the channel pubkeys for the broadcaster
 717         pub fn broadcaster_pubkeys(&self) -> &ChannelPublicKeys {
 718                 if self.holder_is_broadcaster {
 719                         &self.inner.holder_pubkeys
 720                 } else {
 721                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
 722                 }
 723         }
 724
 725         /// Get the channel pubkeys for the countersignatory
 726         pub fn countersignatory_pubkeys(&self) -> &ChannelPublicKeys {
 727                 if self.holder_is_broadcaster {
 728                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
 729                 } else {
 730                         &self.inner.holder_pubkeys
 731                 }
 732         }
 733
 734         /// Get the contest delay applicable to the transactions.
 735         /// Note that the contest delay was selected by the countersignatory.
 736         pub fn contest_delay(&self) -> u16 {
 737                 let counterparty_parameters = self.inner.counterparty_parameters.as_ref().unwrap();
 738                 if self.holder_is_broadcaster { counterparty_parameters.selected_contest_delay } else { self.inner.holder_selected_contest_delay }
 739         }
 740
 741         /// Whether the channel is outbound from the broadcaster.
 742         ///
 743         /// The boolean representing the side that initiated the channel is
 744         /// an input to the commitment number obscure factor computation.
 745         pub fn is_outbound(&self) -> bool {
 746                 if self.holder_is_broadcaster { self.inner.is_outbound_from_holder } else { !self.inner.is_outbound_from_holder }
 747         }
 748
 749         /// The funding outpoint
 750         pub fn funding_outpoint(&self) -> OutPoint {
 751                 self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint()
 752         }
 753 }
 754
 755 /// Information needed to build and sign a holder's commitment transaction.
 756 ///
 757 /// The transaction is only signed once we are ready to broadcast.
 758 #[derive(Clone)]
 759 pub struct HolderCommitmentTransaction {
 760         inner: CommitmentTransaction,
 761         /// Our counterparty's signature for the transaction
 762         pub counterparty_sig: Signature,
 763         /// All non-dust counterparty HTLC signatures, in the order they appear in the transaction
 764         pub counterparty_htlc_sigs: Vec<Signature>,
 765         // Which order the signatures should go in when constructing the final commitment tx witness.
 766         // The user should be able to reconstruct this themselves, so we don't bother to expose it.
 767         holder_sig_first: bool,
 768 }
 769
 770 impl Deref for HolderCommitmentTransaction {
 771         type Target = CommitmentTransaction;
 772
 773         fn deref(&self) -> &Self::Target { &self.inner }
 774 }
 775
 776 impl PartialEq for HolderCommitmentTransaction {
 777         // We dont care whether we are signed in equality comparison
 778         fn eq(&self, o: &Self) -> bool {
 779                 self.inner == o.inner
 780         }
 781 }
 782
 783 impl_writeable_tlv_based!(HolderCommitmentTransaction, {
 784         (0, inner, required),
 785         (2, counterparty_sig, required),
 786         (4, holder_sig_first, required),
 787         (6, counterparty_htlc_sigs, vec_type),
 788 });
 789
 790 impl HolderCommitmentTransaction {
 791         #[cfg(test)]
 792         pub fn dummy() -> Self {
 793                 let secp_ctx = Secp256k1::new();
 794                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 795                 let dummy_sig = secp_ctx.sign(&secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
 796
 797                 let keys = TxCreationKeys {
 798                         per_commitment_point: dummy_key.clone(),
 799                         revocation_key: dummy_key.clone(),
 800                         broadcaster_htlc_key: dummy_key.clone(),
 801                         countersignatory_htlc_key: dummy_key.clone(),
 802                         broadcaster_delayed_payment_key: dummy_key.clone(),
 803                 };
 804                 let channel_pubkeys = ChannelPublicKeys {
 805                         funding_pubkey: dummy_key.clone(),
 806                         revocation_basepoint: dummy_key.clone(),
 807                         payment_point: dummy_key.clone(),
 808                         delayed_payment_basepoint: dummy_key.clone(),
 809                         htlc_basepoint: dummy_key.clone()
 810                 };
 811                 let channel_parameters = ChannelTransactionParameters {
 812                         holder_pubkeys: channel_pubkeys.clone(),
 813                         holder_selected_contest_delay: 0,
 814                         is_outbound_from_holder: false,
 815                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }),
 816                         funding_outpoint: Some(chain::transaction::OutPoint { txid: Default::default(), index: 0 })
 817                 };
 818                 let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
 819                 let inner = CommitmentTransaction::new_with_auxiliary_htlc_data(0, 0, 0, false, dummy_key.clone(), dummy_key.clone(), keys, 0, &mut htlcs_with_aux, &channel_parameters.as_counterparty_broadcastable());
 820                 HolderCommitmentTransaction {
 821                         inner,
 822                         counterparty_sig: dummy_sig,
 823                         counterparty_htlc_sigs: Vec::new(),
 824                         holder_sig_first: false
 825                 }
 826         }
 827
 828         /// Create a new holder transaction with the given counterparty signatures.
 829         /// The funding keys are used to figure out which signature should go first when building the transaction for broadcast.
 830         pub fn new(commitment_tx: CommitmentTransaction, counterparty_sig: Signature, counterparty_htlc_sigs: Vec<Signature>, holder_funding_key: &PublicKey, counterparty_funding_key: &PublicKey) -> Self {
 831                 Self {
 832                         inner: commitment_tx,
 833                         counterparty_sig,
 834                         counterparty_htlc_sigs,
 835                         holder_sig_first: holder_funding_key.serialize()[..] < counterparty_funding_key.serialize()[..],
 836                 }
 837         }
 838
 839         pub(crate) fn add_holder_sig(&self, funding_redeemscript: &Script, holder_sig: Signature) -> Transaction {
 840                 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
 841                 let mut tx = self.inner.built.transaction.clone();
 842                 tx.input[0].witness.push(Vec::new());
 843
 844                 if self.holder_sig_first {
 845                         tx.input[0].witness.push(holder_sig.serialize_der().to_vec());
 846                         tx.input[0].witness.push(self.counterparty_sig.serialize_der().to_vec());
 847                 } else {
 848                         tx.input[0].witness.push(self.counterparty_sig.serialize_der().to_vec());
 849                         tx.input[0].witness.push(holder_sig.serialize_der().to_vec());
 850                 }
 851                 tx.input[0].witness[1].push(SigHashType::All as u8);
 852                 tx.input[0].witness[2].push(SigHashType::All as u8);
 853
 854                 tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
 855                 tx
 856         }
 857 }
 858
 859 /// A pre-built Bitcoin commitment transaction and its txid.
 860 #[derive(Clone)]
 861 pub struct BuiltCommitmentTransaction {
 862         /// The commitment transaction
 863         pub transaction: Transaction,
 864         /// The txid for the commitment transaction.
 865         ///
 866         /// This is provided as a performance optimization, instead of calling transaction.txid()
 867         /// multiple times.
 868         pub txid: Txid,
 869 }
 870
 871 impl_writeable_tlv_based!(BuiltCommitmentTransaction, {
 872         (0, transaction, required),
 873         (2, txid, required),
 874 });
 875
 876 impl BuiltCommitmentTransaction {
 877         /// Get the SIGHASH_ALL sighash value of the transaction.
 878         ///
 879         /// This can be used to verify a signature.
 880         pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
 881                 let sighash = &bip143::SigHashCache::new(&self.transaction).signature_hash(0, funding_redeemscript, channel_value_satoshis, SigHashType::All)[..];
 882                 hash_to_message!(sighash)
 883         }
 884
 885         /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
 886         /// because we are about to broadcast a holder transaction.
 887         pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
 888                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
 889                 secp_ctx.sign(&sighash, funding_key)
 890         }
 891 }
 892
 893 /// This class tracks the per-transaction information needed to build a commitment transaction and to
 894 /// actually build it and sign.  It is used for holder transactions that we sign only when needed
 895 /// and for transactions we sign for the counterparty.
 896 ///
 897 /// This class can be used inside a signer implementation to generate a signature given the relevant
 898 /// secret key.
 899 #[derive(Clone)]
 900 pub struct CommitmentTransaction {
 901         commitment_number: u64,
 902         to_broadcaster_value_sat: u64,
 903         to_countersignatory_value_sat: u64,
 904         feerate_per_kw: u32,
 905         htlcs: Vec<HTLCOutputInCommitment>,
 906         // A boolean that is serialization backwards-compatible
 907         opt_anchors: Option<()>,
 908         // A cache of the parties' pubkeys required to construct the transaction, see doc for trust()
 909         keys: TxCreationKeys,
 910         // For access to the pre-built transaction, see doc for trust()
 911         built: BuiltCommitmentTransaction,
 912 }
 913
 914 impl PartialEq for CommitmentTransaction {
 915         fn eq(&self, o: &Self) -> bool {
 916                 let eq = self.commitment_number == o.commitment_number &&
 917                         self.to_broadcaster_value_sat == o.to_broadcaster_value_sat &&
 918                         self.to_countersignatory_value_sat == o.to_countersignatory_value_sat &&
 919                         self.feerate_per_kw == o.feerate_per_kw &&
 920                         self.htlcs == o.htlcs &&
 921                         self.opt_anchors == o.opt_anchors &&
 922                         self.keys == o.keys;
 923                 if eq {
 924                         debug_assert_eq!(self.built.transaction, o.built.transaction);
 925                         debug_assert_eq!(self.built.txid, o.built.txid);
 926                 }
 927                 eq
 928         }
 929 }
 930
 931 impl_writeable_tlv_based!(CommitmentTransaction, {
 932         (0, commitment_number, required),
 933         (2, to_broadcaster_value_sat, required),
 934         (4, to_countersignatory_value_sat, required),
 935         (6, feerate_per_kw, required),
 936         (8, keys, required),
 937         (10, built, required),
 938         (12, htlcs, vec_type),
 939         (14, opt_anchors, option),
 940 });
 941
 942 impl CommitmentTransaction {
 943         /// Construct an object of the class while assigning transaction output indices to HTLCs.
 944         ///
 945         /// Populates HTLCOutputInCommitment.transaction_output_index in htlcs_with_aux.
 946         ///
 947         /// The generic T allows the caller to match the HTLC output index with auxiliary data.
 948         /// This auxiliary data is not stored in this object.
 949         ///
 950         /// Only include HTLCs that are above the dust limit for the channel.
 951         ///
 952         /// (C-not exported) due to the generic though we likely should expose a version without
 953         pub fn new_with_auxiliary_htlc_data<T>(commitment_number: u64, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, opt_anchors: bool, broadcaster_funding_key: PublicKey, countersignatory_funding_key: PublicKey, keys: TxCreationKeys, feerate_per_kw: u32, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters) -> CommitmentTransaction {
 954                 // Sort outputs and populate output indices while keeping track of the auxiliary data
 955                 let (outputs, htlcs) = Self::internal_build_outputs(&keys, to_broadcaster_value_sat, to_countersignatory_value_sat, htlcs_with_aux, channel_parameters, opt_anchors, &broadcaster_funding_key, &countersignatory_funding_key).unwrap();
 956
 957                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(commitment_number, channel_parameters);
 958                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
 959                 let txid = transaction.txid();
 960                 CommitmentTransaction {
 961                         commitment_number,
 962                         to_broadcaster_value_sat,
 963                         to_countersignatory_value_sat,
 964                         feerate_per_kw,
 965                         htlcs,
 966                         opt_anchors: if opt_anchors { Some(()) } else { None },
 967                         keys,
 968                         built: BuiltCommitmentTransaction {
 969                                 transaction,
 970                                 txid
 971                         },
 972                 }
 973         }
 974
 975         fn internal_rebuild_transaction(&self, keys: &TxCreationKeys, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<BuiltCommitmentTransaction, ()> {
 976                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(self.commitment_number, channel_parameters);
 977
 978                 let mut htlcs_with_aux = self.htlcs.iter().map(|h| (h.clone(), ())).collect();
 979                 let (outputs, _) = Self::internal_build_outputs(keys, self.to_broadcaster_value_sat, self.to_countersignatory_value_sat, &mut htlcs_with_aux, channel_parameters, self.opt_anchors.is_some(), broadcaster_funding_key, countersignatory_funding_key)?;
 980
 981                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
 982                 let txid = transaction.txid();
 983                 let built_transaction = BuiltCommitmentTransaction {
 984                         transaction,
 985                         txid
 986                 };
 987                 Ok(built_transaction)
 988         }
 989
 990         fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec<TxIn>, outputs: Vec<TxOut>) -> Transaction {
 991                 Transaction {
 992                         version: 2,
 993                         lock_time: ((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32),
 994                         input: txins,
 995                         output: outputs,
 996                 }
 997         }
 998
 999         // This is used in two cases:
1000         // - initial sorting of outputs / HTLCs in the constructor, in which case T is auxiliary data the
1001         //   caller needs to have sorted together with the HTLCs so it can keep track of the output index
1002         // - building of a bitcoin transaction during a verify() call, in which case T is just ()
1003         fn internal_build_outputs<T>(keys: &TxCreationKeys, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters, opt_anchors: bool, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<(Vec<TxOut>, Vec<HTLCOutputInCommitment>), ()> {
1004                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1005                 let contest_delay = channel_parameters.contest_delay();
1006
1007                 let mut txouts: Vec<(TxOut, Option<&mut HTLCOutputInCommitment>)> = Vec::new();
1008
1009                 if to_countersignatory_value_sat > 0 {
1010                         let script = script_for_p2wpkh(&countersignatory_pubkeys.payment_point);
1011                         txouts.push((
1012                                 TxOut {
1013                                         script_pubkey: script.clone(),
1014                                         value: to_countersignatory_value_sat,
1015                                 },
1016                                 None,
1017                         ))
1018                 }
1019
1020                 if to_broadcaster_value_sat > 0 {
1021                         let redeem_script = get_revokeable_redeemscript(
1022                                 &keys.revocation_key,
1023                                 contest_delay,
1024                                 &keys.broadcaster_delayed_payment_key,
1025                         );
1026                         txouts.push((
1027                                 TxOut {
1028                                         script_pubkey: redeem_script.to_v0_p2wsh(),
1029                                         value: to_broadcaster_value_sat,
1030                                 },
1031                                 None,
1032                         ));
1033                 }
1034
1035                 if opt_anchors {
1036                         if to_broadcaster_value_sat > 0 || !htlcs_with_aux.is_empty() {
1037                                 let anchor_script = get_anchor_redeemscript(broadcaster_funding_key);
1038                                 txouts.push((
1039                                         TxOut {
1040                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1041                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1042                                         },
1043                                         None,
1044                                 ));
1045                         }
1046
1047                         if to_countersignatory_value_sat > 0 || !htlcs_with_aux.is_empty() {
1048                                 let anchor_script = get_anchor_redeemscript(countersignatory_funding_key);
1049                                 txouts.push((
1050                                         TxOut {
1051                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1052                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1053                                         },
1054                                         None,
1055                                 ));
1056                         }
1057                 }
1058
1059                 let mut htlcs = Vec::with_capacity(htlcs_with_aux.len());
1060                 for (htlc, _) in htlcs_with_aux {
1061                         let script = chan_utils::get_htlc_redeemscript(&htlc, &keys);
1062                         let txout = TxOut {
1063                                 script_pubkey: script.to_v0_p2wsh(),
1064                                 value: htlc.amount_msat / 1000,
1065                         };
1066                         txouts.push((txout, Some(htlc)));
1067                 }
1068
1069                 // Sort output in BIP-69 order (amount, scriptPubkey).  Tie-breaks based on HTLC
1070                 // CLTV expiration height.
1071                 sort_outputs(&mut txouts, |a, b| {
1072                         if let &Some(ref a_htlcout) = a {
1073                                 if let &Some(ref b_htlcout) = b {
1074                                         a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
1075                                                 // Note that due to hash collisions, we have to have a fallback comparison
1076                                                 // here for fuzztarget mode (otherwise at least chanmon_fail_consistency
1077                                                 // may fail)!
1078                                                 .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
1079                                 // For non-HTLC outputs, if they're copying our SPK we don't really care if we
1080                                 // close the channel due to mismatches - they're doing something dumb:
1081                                 } else { cmp::Ordering::Equal }
1082                         } else { cmp::Ordering::Equal }
1083                 });
1084
1085                 let mut outputs = Vec::with_capacity(txouts.len());
1086                 for (idx, out) in txouts.drain(..).enumerate() {
1087                         if let Some(htlc) = out.1 {
1088                                 htlc.transaction_output_index = Some(idx as u32);
1089                                 htlcs.push(htlc.clone());
1090                         }
1091                         outputs.push(out.0);
1092                 }
1093                 Ok((outputs, htlcs))
1094         }
1095
1096         fn internal_build_inputs(commitment_number: u64, channel_parameters: &DirectedChannelTransactionParameters) -> (u64, Vec<TxIn>) {
1097                 let broadcaster_pubkeys = channel_parameters.broadcaster_pubkeys();
1098                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1099                 let commitment_transaction_number_obscure_factor = get_commitment_transaction_number_obscure_factor(
1100                         &broadcaster_pubkeys.payment_point,
1101                         &countersignatory_pubkeys.payment_point,
1102                         channel_parameters.is_outbound(),
1103                 );
1104
1105                 let obscured_commitment_transaction_number =
1106                         commitment_transaction_number_obscure_factor ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
1107
1108                 let txins = {
1109                         let mut ins: Vec<TxIn> = Vec::new();
1110                         ins.push(TxIn {
1111                                 previous_output: channel_parameters.funding_outpoint(),
1112                                 script_sig: Script::new(),
1113                                 sequence: ((0x80 as u32) << 8 * 3)
1114                                         | ((obscured_commitment_transaction_number >> 3 * 8) as u32),
1115                                 witness: Vec::new(),
1116                         });
1117                         ins
1118                 };
1119                 (obscured_commitment_transaction_number, txins)
1120         }
1121
1122         /// The backwards-counting commitment number
1123         pub fn commitment_number(&self) -> u64 {
1124                 self.commitment_number
1125         }
1126
1127         /// The value to be sent to the broadcaster
1128         pub fn to_broadcaster_value_sat(&self) -> u64 {
1129                 self.to_broadcaster_value_sat
1130         }
1131
1132         /// The value to be sent to the counterparty
1133         pub fn to_countersignatory_value_sat(&self) -> u64 {
1134                 self.to_countersignatory_value_sat
1135         }
1136
1137         /// The feerate paid per 1000-weight-unit in this commitment transaction.
1138         pub fn feerate_per_kw(&self) -> u32 {
1139                 self.feerate_per_kw
1140         }
1141
1142         /// The non-dust HTLCs (direction, amt, height expiration, hash, transaction output index)
1143         /// which were included in this commitment transaction in output order.
1144         /// The transaction index is always populated.
1145         ///
1146         /// (C-not exported) as we cannot currently convert Vec references to/from C, though we should
1147         /// expose a less effecient version which creates a Vec of references in the future.
1148         pub fn htlcs(&self) -> &Vec<HTLCOutputInCommitment> {
1149                 &self.htlcs
1150         }
1151
1152         /// Trust our pre-built transaction and derived transaction creation public keys.
1153         ///
1154         /// Applies a wrapper which allows access to these fields.
1155         ///
1156         /// This should only be used if you fully trust the builder of this object.  It should not
1157         ///     be used by an external signer - instead use the verify function.
1158         pub fn trust(&self) -> TrustedCommitmentTransaction {
1159                 TrustedCommitmentTransaction { inner: self }
1160         }
1161
1162         /// Verify our pre-built transaction and derived transaction creation public keys.
1163         ///
1164         /// Applies a wrapper which allows access to these fields.
1165         ///
1166         /// An external validating signer must call this method before signing
1167         /// or using the built transaction.
1168         pub fn verify<T: secp256k1::Signing + secp256k1::Verification>(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TrustedCommitmentTransaction, ()> {
1169                 // This is the only field of the key cache that we trust
1170                 let per_commitment_point = self.keys.per_commitment_point;
1171                 let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx).unwrap();
1172                 if keys != self.keys {
1173                         return Err(());
1174                 }
1175                 let tx = self.internal_rebuild_transaction(&keys, channel_parameters, &broadcaster_keys.funding_pubkey, &countersignatory_keys.funding_pubkey)?;
1176                 if self.built.transaction != tx.transaction || self.built.txid != tx.txid {
1177                         return Err(());
1178                 }
1179                 Ok(TrustedCommitmentTransaction { inner: self })
1180         }
1181 }
1182
1183 /// A wrapper on CommitmentTransaction indicating that the derived fields (the built bitcoin
1184 /// transaction and the transaction creation keys) are trusted.
1185 ///
1186 /// See trust() and verify() functions on CommitmentTransaction.
1187 ///
1188 /// This structure implements Deref.
1189 pub struct TrustedCommitmentTransaction<'a> {
1190         inner: &'a CommitmentTransaction,
1191 }
1192
1193 impl<'a> Deref for TrustedCommitmentTransaction<'a> {
1194         type Target = CommitmentTransaction;
1195
1196         fn deref(&self) -> &Self::Target { self.inner }
1197 }
1198
1199 impl<'a> TrustedCommitmentTransaction<'a> {
1200         /// The transaction ID of the built Bitcoin transaction
1201         pub fn txid(&self) -> Txid {
1202                 self.inner.built.txid
1203         }
1204
1205         /// The pre-built Bitcoin commitment transaction
1206         pub fn built_transaction(&self) -> &BuiltCommitmentTransaction {
1207                 &self.inner.built
1208         }
1209
1210         /// The pre-calculated transaction creation public keys.
1211         pub fn keys(&self) -> &TxCreationKeys {
1212                 &self.inner.keys
1213         }
1214
1215         /// Get a signature for each HTLC which was included in the commitment transaction (ie for
1216         /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
1217         ///
1218         /// The returned Vec has one entry for each HTLC, and in the same order.
1219         pub fn get_htlc_sigs<T: secp256k1::Signing>(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
1220                 let inner = self.inner;
1221                 let keys = &inner.keys;
1222                 let txid = inner.built.txid;
1223                 let mut ret = Vec::with_capacity(inner.htlcs.len());
1224                 let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key).map_err(|_| ())?;
1225
1226                 for this_htlc in inner.htlcs.iter() {
1227                         assert!(this_htlc.transaction_output_index.is_some());
1228                         let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1229
1230                         let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
1231
1232                         let sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, SigHashType::All)[..]);
1233                         ret.push(secp_ctx.sign(&sighash, &holder_htlc_key));
1234                 }
1235                 Ok(ret)
1236         }
1237
1238         /// Gets a signed HTLC transaction given a preimage (for !htlc.offered) and the holder HTLC transaction signature.
1239         pub(crate) fn get_signed_htlc_tx(&self, channel_parameters: &DirectedChannelTransactionParameters, htlc_index: usize, counterparty_signature: &Signature, signature: &Signature, preimage: &Option<PaymentPreimage>) -> Transaction {
1240                 let inner = self.inner;
1241                 let keys = &inner.keys;
1242                 let txid = inner.built.txid;
1243                 let this_htlc = &inner.htlcs[htlc_index];
1244                 assert!(this_htlc.transaction_output_index.is_some());
1245                 // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction.
1246                 if !this_htlc.offered && preimage.is_none() { unreachable!(); }
1247                 // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
1248                 if  this_htlc.offered && preimage.is_some() { unreachable!(); }
1249
1250                 let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1251
1252                 let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
1253
1254                 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
1255                 htlc_tx.input[0].witness.push(Vec::new());
1256
1257                 htlc_tx.input[0].witness.push(counterparty_signature.serialize_der().to_vec());
1258                 htlc_tx.input[0].witness.push(signature.serialize_der().to_vec());
1259                 htlc_tx.input[0].witness[1].push(SigHashType::All as u8);
1260                 htlc_tx.input[0].witness[2].push(SigHashType::All as u8);
1261
1262                 if this_htlc.offered {
1263                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
1264                         htlc_tx.input[0].witness.push(Vec::new());
1265                 } else {
1266                         htlc_tx.input[0].witness.push(preimage.unwrap().0.to_vec());
1267                 }
1268
1269                 htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
1270                 htlc_tx
1271         }
1272 }
1273
1274 /// Commitment transaction numbers which appear in the transactions themselves are XOR'd with a
1275 /// shared secret first. This prevents on-chain observers from discovering how many commitment
1276 /// transactions occurred in a channel before it was closed.
1277 ///
1278 /// This function gets the shared secret from relevant channel public keys and can be used to
1279 /// "decrypt" the commitment transaction number given a commitment transaction on-chain.
1280 pub fn get_commitment_transaction_number_obscure_factor(
1281         broadcaster_payment_basepoint: &PublicKey,
1282         countersignatory_payment_basepoint: &PublicKey,
1283         outbound_from_broadcaster: bool,
1284 ) -> u64 {
1285         let mut sha = Sha256::engine();
1286
1287         if outbound_from_broadcaster {
1288                 sha.input(&broadcaster_payment_basepoint.serialize());
1289                 sha.input(&countersignatory_payment_basepoint.serialize());
1290         } else {
1291                 sha.input(&countersignatory_payment_basepoint.serialize());
1292                 sha.input(&broadcaster_payment_basepoint.serialize());
1293         }
1294         let res = Sha256::from_engine(sha).into_inner();
1295
1296         ((res[26] as u64) << 5 * 8)
1297                 | ((res[27] as u64) << 4 * 8)
1298                 | ((res[28] as u64) << 3 * 8)
1299                 | ((res[29] as u64) << 2 * 8)
1300                 | ((res[30] as u64) << 1 * 8)
1301                 | ((res[31] as u64) << 0 * 8)
1302 }
1303
1304 fn script_for_p2wpkh(key: &PublicKey) -> Script {
1305         Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1306                 .push_slice(&WPubkeyHash::hash(&key.serialize())[..])
1307                 .into_script()
1308 }
1309
1310 #[cfg(test)]
1311 mod tests {
1312         use super::CounterpartyCommitmentSecrets;
1313         use ::{hex, chain};
1314         use prelude::*;
1315         use ln::chan_utils::{CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
1316         use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
1317         use util::test_utils;
1318         use chain::keysinterface::{KeysInterface, BaseSign};
1319         use bitcoin::Network;
1320         use ln::PaymentHash;
1321
1322         #[test]
1323         fn test_anchors() {
1324                 let secp_ctx = Secp256k1::new();
1325
1326                 let seed = [42; 32];
1327                 let network = Network::Testnet;
1328                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
1329                 let signer = keys_provider.get_channel_signer(false, 3000);
1330                 let counterparty_signer = keys_provider.get_channel_signer(false, 3000);
1331                 let delayed_payment_base = &signer.pubkeys().delayed_payment_basepoint;
1332                 let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
1333                 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
1334                 let htlc_basepoint = &signer.pubkeys().htlc_basepoint;
1335                 let holder_pubkeys = signer.pubkeys();
1336                 let counterparty_pubkeys = counterparty_signer.pubkeys();
1337                 let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();
1338                 let channel_parameters = ChannelTransactionParameters {
1339                         holder_pubkeys: holder_pubkeys.clone(),
1340                         holder_selected_contest_delay: 0,
1341                         is_outbound_from_holder: false,
1342                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }),
1343                         funding_outpoint: Some(chain::transaction::OutPoint { txid: Default::default(), index: 0 })
1344                 };
1345
1346                 let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
1347
1348                 // Generate broadcaster and counterparty outputs
1349                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1350                         0, 1000, 2000,
1351                         false,
1352                         holder_pubkeys.funding_pubkey,
1353                         counterparty_pubkeys.funding_pubkey,
1354                         keys.clone(), 1,
1355                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1356                 );
1357                 assert_eq!(tx.built.transaction.output.len(), 2);
1358
1359                 // Generate broadcaster and counterparty outputs as well as two anchors
1360                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1361                         0, 1000, 2000,
1362                         true,
1363                         holder_pubkeys.funding_pubkey,
1364                         counterparty_pubkeys.funding_pubkey,
1365                         keys.clone(), 1,
1366                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1367                 );
1368                 assert_eq!(tx.built.transaction.output.len(), 4);
1369
1370                 // Generate broadcaster output and anchor
1371                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1372                         0, 3000, 0,
1373                         true,
1374                         holder_pubkeys.funding_pubkey,
1375                         counterparty_pubkeys.funding_pubkey,
1376                         keys.clone(), 1,
1377                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1378                 );
1379                 assert_eq!(tx.built.transaction.output.len(), 2);
1380
1381                 // Generate counterparty output and anchor
1382                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1383                         0, 0, 3000,
1384                         true,
1385                         holder_pubkeys.funding_pubkey,
1386                         counterparty_pubkeys.funding_pubkey,
1387                         keys.clone(), 1,
1388                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1389                 );
1390                 assert_eq!(tx.built.transaction.output.len(), 2);
1391
1392                 // Generate broadcaster output, an HTLC output and two anchors
1393                 let payment_hash = PaymentHash([42; 32]);
1394                 let htlc_info = HTLCOutputInCommitment {
1395                         offered: false,
1396                         amount_msat: 1000000,
1397                         cltv_expiry: 100,
1398                         payment_hash,
1399                         transaction_output_index: None,
1400                 };
1401
1402                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1403                         0, 3000, 0,
1404                         true,
1405                         holder_pubkeys.funding_pubkey,
1406                         counterparty_pubkeys.funding_pubkey,
1407                         keys.clone(), 1,
1408                         &mut vec![(htlc_info, ())], &channel_parameters.as_holder_broadcastable()
1409                 );
1410                 assert_eq!(tx.built.transaction.output.len(), 4);
1411         }
1412
1413         #[test]
1414         fn test_per_commitment_storage() {
1415                 // Test vectors from BOLT 3:
1416                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1417                 let mut monitor;
1418
1419                 macro_rules! test_secrets {
1420                         () => {
1421                                 let mut idx = 281474976710655;
1422                                 for secret in secrets.iter() {
1423                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1424                                         idx -= 1;
1425                                 }
1426                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1427                                 assert!(monitor.get_secret(idx).is_none());
1428                         };
1429                 }
1430
1431                 {
1432                         // insert_secret correct sequence
1433                         monitor = CounterpartyCommitmentSecrets::new();
1434                         secrets.clear();
1435
1436                         secrets.push([0; 32]);
1437                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1438                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1439                         test_secrets!();
1440
1441                         secrets.push([0; 32]);
1442                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1443                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1444                         test_secrets!();
1445
1446                         secrets.push([0; 32]);
1447                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1448                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1449                         test_secrets!();
1450
1451                         secrets.push([0; 32]);
1452                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1453                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1454                         test_secrets!();
1455
1456                         secrets.push([0; 32]);
1457                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1458                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1459                         test_secrets!();
1460
1461                         secrets.push([0; 32]);
1462                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1463                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1464                         test_secrets!();
1465
1466                         secrets.push([0; 32]);
1467                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1468                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1469                         test_secrets!();
1470
1471                         secrets.push([0; 32]);
1472                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1473                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
1474                         test_secrets!();
1475                 }
1476
1477                 {
1478                         // insert_secret #1 incorrect
1479                         monitor = CounterpartyCommitmentSecrets::new();
1480                         secrets.clear();
1481
1482                         secrets.push([0; 32]);
1483                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1484                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1485                         test_secrets!();
1486
1487                         secrets.push([0; 32]);
1488                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1489                         assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err());
1490                 }
1491
1492                 {
1493                         // insert_secret #2 incorrect (#1 derived from incorrect)
1494                         monitor = CounterpartyCommitmentSecrets::new();
1495                         secrets.clear();
1496
1497                         secrets.push([0; 32]);
1498                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1499                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1500                         test_secrets!();
1501
1502                         secrets.push([0; 32]);
1503                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1504                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1505                         test_secrets!();
1506
1507                         secrets.push([0; 32]);
1508                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1509                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1510                         test_secrets!();
1511
1512                         secrets.push([0; 32]);
1513                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1514                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1515                 }
1516
1517                 {
1518                         // insert_secret #3 incorrect
1519                         monitor = CounterpartyCommitmentSecrets::new();
1520                         secrets.clear();
1521
1522                         secrets.push([0; 32]);
1523                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1524                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1525                         test_secrets!();
1526
1527                         secrets.push([0; 32]);
1528                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1529                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1530                         test_secrets!();
1531
1532                         secrets.push([0; 32]);
1533                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1534                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1535                         test_secrets!();
1536
1537                         secrets.push([0; 32]);
1538                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1539                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1540                 }
1541
1542                 {
1543                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1544                         monitor = CounterpartyCommitmentSecrets::new();
1545                         secrets.clear();
1546
1547                         secrets.push([0; 32]);
1548                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1549                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1550                         test_secrets!();
1551
1552                         secrets.push([0; 32]);
1553                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1554                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1555                         test_secrets!();
1556
1557                         secrets.push([0; 32]);
1558                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1559                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1560                         test_secrets!();
1561
1562                         secrets.push([0; 32]);
1563                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1564                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1565                         test_secrets!();
1566
1567                         secrets.push([0; 32]);
1568                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1569                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1570                         test_secrets!();
1571
1572                         secrets.push([0; 32]);
1573                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1574                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1575                         test_secrets!();
1576
1577                         secrets.push([0; 32]);
1578                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1579                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1580                         test_secrets!();
1581
1582                         secrets.push([0; 32]);
1583                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1584                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1585                 }
1586
1587                 {
1588                         // insert_secret #5 incorrect
1589                         monitor = CounterpartyCommitmentSecrets::new();
1590                         secrets.clear();
1591
1592                         secrets.push([0; 32]);
1593                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1594                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1595                         test_secrets!();
1596
1597                         secrets.push([0; 32]);
1598                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1599                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1600                         test_secrets!();
1601
1602                         secrets.push([0; 32]);
1603                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1604                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1605                         test_secrets!();
1606
1607                         secrets.push([0; 32]);
1608                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1609                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1610                         test_secrets!();
1611
1612                         secrets.push([0; 32]);
1613                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1614                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1615                         test_secrets!();
1616
1617                         secrets.push([0; 32]);
1618                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1619                         assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err());
1620                 }
1621
1622                 {
1623                         // insert_secret #6 incorrect (5 derived from incorrect)
1624                         monitor = CounterpartyCommitmentSecrets::new();
1625                         secrets.clear();
1626
1627                         secrets.push([0; 32]);
1628                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1629                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1630                         test_secrets!();
1631
1632                         secrets.push([0; 32]);
1633                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1634                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1635                         test_secrets!();
1636
1637                         secrets.push([0; 32]);
1638                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1639                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1640                         test_secrets!();
1641
1642                         secrets.push([0; 32]);
1643                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1644                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1645                         test_secrets!();
1646
1647                         secrets.push([0; 32]);
1648                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1649                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1650                         test_secrets!();
1651
1652                         secrets.push([0; 32]);
1653                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1654                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1655                         test_secrets!();
1656
1657                         secrets.push([0; 32]);
1658                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1659                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1660                         test_secrets!();
1661
1662                         secrets.push([0; 32]);
1663                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1664                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1665                 }
1666
1667                 {
1668                         // insert_secret #7 incorrect
1669                         monitor = CounterpartyCommitmentSecrets::new();
1670                         secrets.clear();
1671
1672                         secrets.push([0; 32]);
1673                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1674                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1675                         test_secrets!();
1676
1677                         secrets.push([0; 32]);
1678                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1679                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1680                         test_secrets!();
1681
1682                         secrets.push([0; 32]);
1683                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1684                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1685                         test_secrets!();
1686
1687                         secrets.push([0; 32]);
1688                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1689                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1690                         test_secrets!();
1691
1692                         secrets.push([0; 32]);
1693                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1694                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1695                         test_secrets!();
1696
1697                         secrets.push([0; 32]);
1698                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1699                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1700                         test_secrets!();
1701
1702                         secrets.push([0; 32]);
1703                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
1704                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1705                         test_secrets!();
1706
1707                         secrets.push([0; 32]);
1708                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1709                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1710                 }
1711
1712                 {
1713                         // insert_secret #8 incorrect
1714                         monitor = CounterpartyCommitmentSecrets::new();
1715                         secrets.clear();
1716
1717                         secrets.push([0; 32]);
1718                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1719                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1720                         test_secrets!();
1721
1722                         secrets.push([0; 32]);
1723                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1724                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1725                         test_secrets!();
1726
1727                         secrets.push([0; 32]);
1728                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1729                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1730                         test_secrets!();
1731
1732                         secrets.push([0; 32]);
1733                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1734                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1735                         test_secrets!();
1736
1737                         secrets.push([0; 32]);
1738                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1739                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1740                         test_secrets!();
1741
1742                         secrets.push([0; 32]);
1743                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1744                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1745                         test_secrets!();
1746
1747                         secrets.push([0; 32]);
1748                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1749                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1750                         test_secrets!();
1751
1752                         secrets.push([0; 32]);
1753                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
1754                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1755                 }
1756         }
1757 }