1 // This file is Copyright its original authors, visible in version control
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
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.
13 use bitcoin::blockdata::script::{Script,Builder};
14 use bitcoin::blockdata::opcodes;
15 use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, EcdsaSighashType};
16 use bitcoin::util::sighash;
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};
23 use crate::ln::{PaymentHash, PaymentPreimage};
24 use crate::ln::msgs::DecodeError;
25 use crate::util::ser::{Readable, Writeable, Writer};
26 use crate::util::{byte_utils, transaction_utils};
28 use bitcoin::hash_types::WPubkeyHash;
29 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
30 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
31 use bitcoin::secp256k1::Error as SecpError;
32 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
35 use crate::prelude::*;
37 use crate::ln::chan_utils;
38 use crate::util::transaction_utils::sort_outputs;
39 use crate::ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI};
42 use crate::util::crypto::sign;
44 pub(crate) const MAX_HTLCS: u16 = 483;
45 pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
46 pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136;
47 // The weight of `accepted_htlc_script` can vary in function of its CLTV argument value. We define a
48 // range that encompasses both its non-anchors and anchors variants.
49 pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136;
50 pub(crate) const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
52 /// Gets the weight for an HTLC-Success transaction.
54 pub fn htlc_success_tx_weight(opt_anchors: bool) -> u64 {
55 const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
56 const HTLC_SUCCESS_ANCHOR_TX_WEIGHT: u64 = 706;
57 if opt_anchors { HTLC_SUCCESS_ANCHOR_TX_WEIGHT } else { HTLC_SUCCESS_TX_WEIGHT }
60 /// Gets the weight for an HTLC-Timeout transaction.
62 pub fn htlc_timeout_tx_weight(opt_anchors: bool) -> u64 {
63 const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
64 const HTLC_TIMEOUT_ANCHOR_TX_WEIGHT: u64 = 666;
65 if opt_anchors { HTLC_TIMEOUT_ANCHOR_TX_WEIGHT } else { HTLC_TIMEOUT_TX_WEIGHT }
68 #[derive(PartialEq, Eq)]
69 pub(crate) enum HTLCClaim {
78 /// Check if a given input witness attempts to claim a HTLC.
79 pub(crate) fn from_witness(witness: &Witness) -> Option<Self> {
80 debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT);
81 if witness.len() < 2 {
84 let witness_script = witness.last().unwrap();
85 let second_to_last = witness.second_to_last().unwrap();
86 if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT {
87 if witness.len() == 3 && second_to_last.len() == 33 {
88 // <revocation sig> <revocationpubkey> <witness_script>
89 Some(Self::Revocation)
90 } else if witness.len() == 3 && second_to_last.len() == 32 {
91 // <remotehtlcsig> <payment_preimage> <witness_script>
92 Some(Self::OfferedPreimage)
93 } else if witness.len() == 5 && second_to_last.len() == 0 {
94 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
95 Some(Self::OfferedTimeout)
99 } else if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS {
100 // It's possible for the weight of `offered_htlc_script` and `accepted_htlc_script` to
101 // match so we check for both here.
102 if witness.len() == 3 && second_to_last.len() == 33 {
103 // <revocation sig> <revocationpubkey> <witness_script>
104 Some(Self::Revocation)
105 } else if witness.len() == 3 && second_to_last.len() == 32 {
106 // <remotehtlcsig> <payment_preimage> <witness_script>
107 Some(Self::OfferedPreimage)
108 } else if witness.len() == 5 && second_to_last.len() == 0 {
109 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
110 Some(Self::OfferedTimeout)
111 } else if witness.len() == 3 && second_to_last.len() == 0 {
112 // <remotehtlcsig> <> <witness_script>
113 Some(Self::AcceptedTimeout)
114 } else if witness.len() == 5 && second_to_last.len() == 32 {
115 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
116 Some(Self::AcceptedPreimage)
120 } else if witness_script.len() > MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT &&
121 witness_script.len() <= MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT {
122 // Handle remaining range of ACCEPTED_HTLC_SCRIPT_WEIGHT.
123 if witness.len() == 3 && second_to_last.len() == 33 {
124 // <revocation sig> <revocationpubkey> <witness_script>
125 Some(Self::Revocation)
126 } else if witness.len() == 3 && second_to_last.len() == 0 {
127 // <remotehtlcsig> <> <witness_script>
128 Some(Self::AcceptedTimeout)
129 } else if witness.len() == 5 && second_to_last.len() == 32 {
130 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
131 Some(Self::AcceptedPreimage)
141 // Various functions for key derivation and transaction creation for use within channels. Primarily
142 // used in Channel and ChannelMonitor.
144 /// Build the commitment secret from the seed and the commitment number
145 pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] {
146 let mut res: [u8; 32] = commitment_seed.clone();
149 if idx & (1 << bitpos) == (1 << bitpos) {
150 res[bitpos / 8] ^= 1 << (bitpos & 7);
151 res = Sha256::hash(&res).into_inner();
157 /// Build a closing transaction
158 pub fn build_closing_transaction(to_holder_value_sat: u64, to_counterparty_value_sat: u64, to_holder_script: Script, to_counterparty_script: Script, funding_outpoint: OutPoint) -> Transaction {
160 let mut ins: Vec<TxIn> = Vec::new();
162 previous_output: funding_outpoint,
163 script_sig: Script::new(),
164 sequence: Sequence::MAX,
165 witness: Witness::new(),
170 let mut txouts: Vec<(TxOut, ())> = Vec::new();
172 if to_counterparty_value_sat > 0 {
174 script_pubkey: to_counterparty_script,
175 value: to_counterparty_value_sat
179 if to_holder_value_sat > 0 {
181 script_pubkey: to_holder_script,
182 value: to_holder_value_sat
186 transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
188 let mut outputs: Vec<TxOut> = Vec::new();
189 for out in txouts.drain(..) {
195 lock_time: PackedLockTime::ZERO,
201 /// Implements the per-commitment secret storage scheme from
202 /// [BOLT 3](https://github.com/lightning/bolts/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
204 /// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes
207 pub struct CounterpartyCommitmentSecrets {
208 old_secrets: [([u8; 32], u64); 49],
211 impl Eq for CounterpartyCommitmentSecrets {}
212 impl PartialEq for CounterpartyCommitmentSecrets {
213 fn eq(&self, other: &Self) -> bool {
214 for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
215 if secret != o_secret || idx != o_idx {
223 impl CounterpartyCommitmentSecrets {
224 /// Creates a new empty `CounterpartyCommitmentSecrets` structure.
225 pub fn new() -> Self {
226 Self { old_secrets: [([0; 32], 1 << 48); 49], }
230 fn place_secret(idx: u64) -> u8 {
232 if idx & (1 << i) == (1 << i) {
239 /// Returns the minimum index of all stored secrets. Note that indexes start
240 /// at 1 << 48 and get decremented by one for each new secret.
241 pub fn get_min_seen_secret(&self) -> u64 {
242 //TODO This can be optimized?
243 let mut min = 1 << 48;
244 for &(_, idx) in self.old_secrets.iter() {
253 fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
254 let mut res: [u8; 32] = secret;
256 let bitpos = bits - 1 - i;
257 if idx & (1 << bitpos) == (1 << bitpos) {
258 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
259 res = Sha256::hash(&res).into_inner();
265 /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret
266 /// was generated in accordance with BOLT 3 and is consistent with previous secrets.
267 pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
268 let pos = Self::place_secret(idx);
270 let (old_secret, old_idx) = self.old_secrets[i as usize];
271 if Self::derive_secret(secret, pos, old_idx) != old_secret {
275 if self.get_min_seen_secret() <= idx {
278 self.old_secrets[pos as usize] = (secret, idx);
282 /// Returns the secret at `idx`.
283 /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`].
284 pub fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
285 for i in 0..self.old_secrets.len() {
286 if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
287 return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
290 assert!(idx < self.get_min_seen_secret());
295 impl Writeable for CounterpartyCommitmentSecrets {
296 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
297 for &(ref secret, ref idx) in self.old_secrets.iter() {
298 writer.write_all(secret)?;
299 writer.write_all(&byte_utils::be64_to_array(*idx))?;
301 write_tlv_fields!(writer, {});
305 impl Readable for CounterpartyCommitmentSecrets {
306 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
307 let mut old_secrets = [([0; 32], 1 << 48); 49];
308 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
309 *secret = Readable::read(reader)?;
310 *idx = Readable::read(reader)?;
312 read_tlv_fields!(reader, {});
313 Ok(Self { old_secrets })
317 /// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
318 /// from the base secret and the per_commitment_point.
320 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
321 /// generated (ie our own).
322 pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, SecpError> {
323 let mut sha = Sha256::engine();
324 sha.input(&per_commitment_point.serialize());
325 sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
326 let res = Sha256::from_engine(sha).into_inner();
328 base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap())
331 /// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
332 /// from the base point and the per_commitment_key. This is the public equivalent of
333 /// derive_private_key - using only public keys to derive a public key instead of private keys.
335 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
336 /// generated (ie our own).
337 pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, SecpError> {
338 let mut sha = Sha256::engine();
339 sha.input(&per_commitment_point.serialize());
340 sha.input(&base_point.serialize());
341 let res = Sha256::from_engine(sha).into_inner();
343 let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&res)?);
344 base_point.combine(&hashkey)
347 /// Derives a per-commitment-transaction revocation key from its constituent parts.
349 /// Only the cheating participant owns a valid witness to propagate a revoked
350 /// commitment transaction, thus per_commitment_secret always come from cheater
351 /// and revocation_base_secret always come from punisher, which is the broadcaster
352 /// of the transaction spending with this key knowledge.
354 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
355 /// generated (ie our own).
356 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> {
357 let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret);
358 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
360 let rev_append_commit_hash_key = {
361 let mut sha = Sha256::engine();
362 sha.input(&countersignatory_revocation_base_point.serialize());
363 sha.input(&per_commitment_point.serialize());
365 Sha256::from_engine(sha).into_inner()
367 let commit_append_rev_hash_key = {
368 let mut sha = Sha256::engine();
369 sha.input(&per_commitment_point.serialize());
370 sha.input(&countersignatory_revocation_base_point.serialize());
372 Sha256::from_engine(sha).into_inner()
375 let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
376 let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
377 countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap())
380 /// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
381 /// the public equivalend of derive_private_revocation_key - using only public keys to derive a
382 /// public key instead of private keys.
384 /// Only the cheating participant owns a valid witness to propagate a revoked
385 /// commitment transaction, thus per_commitment_point always come from cheater
386 /// and revocation_base_point always come from punisher, which is the broadcaster
387 /// of the transaction spending with this key knowledge.
389 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
390 /// generated (ie our own).
391 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> {
392 let rev_append_commit_hash_key = {
393 let mut sha = Sha256::engine();
394 sha.input(&countersignatory_revocation_base_point.serialize());
395 sha.input(&per_commitment_point.serialize());
397 Sha256::from_engine(sha).into_inner()
399 let commit_append_rev_hash_key = {
400 let mut sha = Sha256::engine();
401 sha.input(&per_commitment_point.serialize());
402 sha.input(&countersignatory_revocation_base_point.serialize());
404 Sha256::from_engine(sha).into_inner()
407 let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
408 let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
409 countersignatory_contrib.combine(&broadcaster_contrib)
412 /// The set of public keys which are used in the creation of one commitment transaction.
413 /// These are derived from the channel base keys and per-commitment data.
415 /// A broadcaster key is provided from potential broadcaster of the computed transaction.
416 /// A countersignatory key is coming from a protocol participant unable to broadcast the
419 /// These keys are assumed to be good, either because the code derived them from
420 /// channel basepoints via the new function, or they were obtained via
421 /// CommitmentTransaction.trust().keys() because we trusted the source of the
422 /// pre-calculated keys.
423 #[derive(PartialEq, Eq, Clone)]
424 pub struct TxCreationKeys {
425 /// The broadcaster's per-commitment public key which was used to derive the other keys.
426 pub per_commitment_point: PublicKey,
427 /// The revocation key which is used to allow the broadcaster of the commitment
428 /// transaction to provide their counterparty the ability to punish them if they broadcast
430 pub revocation_key: PublicKey,
431 /// Broadcaster's HTLC Key
432 pub broadcaster_htlc_key: PublicKey,
433 /// Countersignatory's HTLC Key
434 pub countersignatory_htlc_key: PublicKey,
435 /// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay)
436 pub broadcaster_delayed_payment_key: PublicKey,
439 impl_writeable_tlv_based!(TxCreationKeys, {
440 (0, per_commitment_point, required),
441 (2, revocation_key, required),
442 (4, broadcaster_htlc_key, required),
443 (6, countersignatory_htlc_key, required),
444 (8, broadcaster_delayed_payment_key, required),
447 /// One counterparty's public keys which do not change over the life of a channel.
448 #[derive(Clone, PartialEq, Eq)]
449 pub struct ChannelPublicKeys {
450 /// The public key which is used to sign all commitment transactions, as it appears in the
451 /// on-chain channel lock-in 2-of-2 multisig output.
452 pub funding_pubkey: PublicKey,
453 /// The base point which is used (with derive_public_revocation_key) to derive per-commitment
454 /// revocation keys. This is combined with the per-commitment-secret generated by the
455 /// counterparty to create a secret which the counterparty can reveal to revoke previous
457 pub revocation_basepoint: PublicKey,
458 /// The public key on which the non-broadcaster (ie the countersignatory) receives an immediately
459 /// spendable primary channel balance on the broadcaster's commitment transaction. This key is
460 /// static across every commitment transaction.
461 pub payment_point: PublicKey,
462 /// The base point which is used (with derive_public_key) to derive a per-commitment payment
463 /// public key which receives non-HTLC-encumbered funds which are only available for spending
464 /// after some delay (or can be claimed via the revocation path).
465 pub delayed_payment_basepoint: PublicKey,
466 /// The base point which is used (with derive_public_key) to derive a per-commitment public key
467 /// which is used to encumber HTLC-in-flight outputs.
468 pub htlc_basepoint: PublicKey,
471 impl_writeable_tlv_based!(ChannelPublicKeys, {
472 (0, funding_pubkey, required),
473 (2, revocation_basepoint, required),
474 (4, payment_point, required),
475 (6, delayed_payment_basepoint, required),
476 (8, htlc_basepoint, required),
479 impl TxCreationKeys {
480 /// Create per-state keys from channel base points and the per-commitment point.
481 /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
482 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> {
484 per_commitment_point: per_commitment_point.clone(),
485 revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base)?,
486 broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base)?,
487 countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base)?,
488 broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base)?,
492 /// Generate per-state keys from channel static keys.
493 /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
494 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> {
495 TxCreationKeys::derive_new(
497 &per_commitment_point,
498 &broadcaster_keys.delayed_payment_basepoint,
499 &broadcaster_keys.htlc_basepoint,
500 &countersignatory_keys.revocation_basepoint,
501 &countersignatory_keys.htlc_basepoint,
506 /// The maximum length of a script returned by get_revokeable_redeemscript.
507 // Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public
508 // keys of 33 bytes (+ 1 push).
509 pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2;
511 /// A script either spendable by the revocation
512 /// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
513 /// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions.
514 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> Script {
515 let res = Builder::new().push_opcode(opcodes::all::OP_IF)
516 .push_slice(&revocation_key.serialize())
517 .push_opcode(opcodes::all::OP_ELSE)
518 .push_int(contest_delay as i64)
519 .push_opcode(opcodes::all::OP_CSV)
520 .push_opcode(opcodes::all::OP_DROP)
521 .push_slice(&broadcaster_delayed_payment_key.serialize())
522 .push_opcode(opcodes::all::OP_ENDIF)
523 .push_opcode(opcodes::all::OP_CHECKSIG)
525 debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH);
529 /// Information about an HTLC as it appears in a commitment transaction
530 #[derive(Clone, Debug, PartialEq, Eq)]
531 pub struct HTLCOutputInCommitment {
532 /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
533 /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
534 /// need to compare this value to whether the commitment transaction in question is that of
535 /// the counterparty or our own.
537 /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is
538 /// this divided by 1000.
539 pub amount_msat: u64,
540 /// The CLTV lock-time at which this HTLC expires.
541 pub cltv_expiry: u32,
542 /// The hash of the preimage which unlocks this HTLC.
543 pub payment_hash: PaymentHash,
544 /// The position within the commitment transactions' outputs. This may be None if the value is
545 /// below the dust limit (in which case no output appears in the commitment transaction and the
546 /// value is spent to additional transaction fees).
547 pub transaction_output_index: Option<u32>,
550 impl_writeable_tlv_based!(HTLCOutputInCommitment, {
551 (0, offered, required),
552 (2, amount_msat, required),
553 (4, cltv_expiry, required),
554 (6, payment_hash, required),
555 (8, transaction_output_index, option),
559 pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, opt_anchors: bool, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script {
560 let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner();
562 let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
563 .push_opcode(opcodes::all::OP_HASH160)
564 .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
565 .push_opcode(opcodes::all::OP_EQUAL)
566 .push_opcode(opcodes::all::OP_IF)
567 .push_opcode(opcodes::all::OP_CHECKSIG)
568 .push_opcode(opcodes::all::OP_ELSE)
569 .push_slice(&countersignatory_htlc_key.serialize()[..])
570 .push_opcode(opcodes::all::OP_SWAP)
571 .push_opcode(opcodes::all::OP_SIZE)
573 .push_opcode(opcodes::all::OP_EQUAL)
574 .push_opcode(opcodes::all::OP_NOTIF)
575 .push_opcode(opcodes::all::OP_DROP)
577 .push_opcode(opcodes::all::OP_SWAP)
578 .push_slice(&broadcaster_htlc_key.serialize()[..])
580 .push_opcode(opcodes::all::OP_CHECKMULTISIG)
581 .push_opcode(opcodes::all::OP_ELSE)
582 .push_opcode(opcodes::all::OP_HASH160)
583 .push_slice(&payment_hash160)
584 .push_opcode(opcodes::all::OP_EQUALVERIFY)
585 .push_opcode(opcodes::all::OP_CHECKSIG)
586 .push_opcode(opcodes::all::OP_ENDIF);
588 bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
589 .push_opcode(opcodes::all::OP_CSV)
590 .push_opcode(opcodes::all::OP_DROP);
592 bldr.push_opcode(opcodes::all::OP_ENDIF)
595 let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
596 .push_opcode(opcodes::all::OP_HASH160)
597 .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
598 .push_opcode(opcodes::all::OP_EQUAL)
599 .push_opcode(opcodes::all::OP_IF)
600 .push_opcode(opcodes::all::OP_CHECKSIG)
601 .push_opcode(opcodes::all::OP_ELSE)
602 .push_slice(&countersignatory_htlc_key.serialize()[..])
603 .push_opcode(opcodes::all::OP_SWAP)
604 .push_opcode(opcodes::all::OP_SIZE)
606 .push_opcode(opcodes::all::OP_EQUAL)
607 .push_opcode(opcodes::all::OP_IF)
608 .push_opcode(opcodes::all::OP_HASH160)
609 .push_slice(&payment_hash160)
610 .push_opcode(opcodes::all::OP_EQUALVERIFY)
612 .push_opcode(opcodes::all::OP_SWAP)
613 .push_slice(&broadcaster_htlc_key.serialize()[..])
615 .push_opcode(opcodes::all::OP_CHECKMULTISIG)
616 .push_opcode(opcodes::all::OP_ELSE)
617 .push_opcode(opcodes::all::OP_DROP)
618 .push_int(htlc.cltv_expiry as i64)
619 .push_opcode(opcodes::all::OP_CLTV)
620 .push_opcode(opcodes::all::OP_DROP)
621 .push_opcode(opcodes::all::OP_CHECKSIG)
622 .push_opcode(opcodes::all::OP_ENDIF);
624 bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
625 .push_opcode(opcodes::all::OP_CSV)
626 .push_opcode(opcodes::all::OP_DROP);
628 bldr.push_opcode(opcodes::all::OP_ENDIF)
633 /// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc
634 /// does not need to have its previous_output_index filled.
636 pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, opt_anchors: bool, keys: &TxCreationKeys) -> Script {
637 get_htlc_redeemscript_with_explicit_keys(htlc, opt_anchors, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key)
640 /// Gets the redeemscript for a funding output from the two funding public keys.
641 /// Note that the order of funding public keys does not matter.
642 pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &PublicKey) -> Script {
643 let broadcaster_funding_key = broadcaster.serialize();
644 let countersignatory_funding_key = countersignatory.serialize();
646 let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
647 if broadcaster_funding_key[..] < countersignatory_funding_key[..] {
648 builder.push_slice(&broadcaster_funding_key)
649 .push_slice(&countersignatory_funding_key)
651 builder.push_slice(&countersignatory_funding_key)
652 .push_slice(&broadcaster_funding_key)
653 }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
656 /// Builds an unsigned HTLC-Success or HTLC-Timeout transaction from the given channel and HTLC
657 /// parameters. This is used by [`TrustedCommitmentTransaction::get_htlc_sigs`] to fetch the
658 /// transaction which needs signing, and can be used to construct an HTLC transaction which is
659 /// broadcastable given a counterparty HTLC signature.
661 /// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the
662 /// commitment transaction).
663 pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
664 let mut txins: Vec<TxIn> = Vec::new();
666 previous_output: OutPoint {
667 txid: commitment_txid.clone(),
668 vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
670 script_sig: Script::new(),
671 sequence: Sequence(if opt_anchors { 1 } else { 0 }),
672 witness: Witness::new(),
675 let weight = if htlc.offered {
676 htlc_timeout_tx_weight(opt_anchors)
678 htlc_success_tx_weight(opt_anchors)
680 let output_value = if opt_anchors {
681 htlc.amount_msat / 1000
683 let total_fee = feerate_per_kw as u64 * weight / 1000;
684 htlc.amount_msat / 1000 - total_fee
687 let mut txouts: Vec<TxOut> = Vec::new();
689 script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
695 lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }),
701 /// Gets the witnessScript for the to_remote output when anchors are enabled.
703 pub(crate) fn get_to_countersignatory_with_anchors_redeemscript(payment_point: &PublicKey) -> Script {
705 .push_slice(&payment_point.serialize()[..])
706 .push_opcode(opcodes::all::OP_CHECKSIGVERIFY)
708 .push_opcode(opcodes::all::OP_CSV)
712 /// Gets the witnessScript for an anchor output from the funding public key.
713 /// The witness in the spending input must be:
714 /// <BIP 143 funding_signature>
715 /// After 16 blocks of confirmation, an alternative satisfying witness could be:
717 /// (empty vector required to satisfy compliance with MINIMALIF-standard rule)
719 pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script {
720 Builder::new().push_slice(&funding_pubkey.serialize()[..])
721 .push_opcode(opcodes::all::OP_CHECKSIG)
722 .push_opcode(opcodes::all::OP_IFDUP)
723 .push_opcode(opcodes::all::OP_NOTIF)
725 .push_opcode(opcodes::all::OP_CSV)
726 .push_opcode(opcodes::all::OP_ENDIF)
731 /// Locates the output with an anchor script paying to `funding_pubkey` within `commitment_tx`.
732 pub(crate) fn get_anchor_output<'a>(commitment_tx: &'a Transaction, funding_pubkey: &PublicKey) -> Option<(u32, &'a TxOut)> {
733 let anchor_script = chan_utils::get_anchor_redeemscript(funding_pubkey).to_v0_p2wsh();
734 commitment_tx.output.iter().enumerate()
735 .find(|(_, txout)| txout.script_pubkey == anchor_script)
736 .map(|(idx, txout)| (idx as u32, txout))
739 /// Returns the witness required to satisfy and spend an anchor input.
740 pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness {
741 let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key);
742 let mut funding_sig = funding_sig.serialize_der().to_vec();
743 funding_sig.push(EcdsaSighashType::All as u8);
744 Witness::from_vec(vec![funding_sig, anchor_redeem_script.to_bytes()])
747 /// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
748 /// The fields are organized by holder/counterparty.
750 /// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters
751 /// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions.
753 pub struct ChannelTransactionParameters {
754 /// Holder public keys
755 pub holder_pubkeys: ChannelPublicKeys,
756 /// The contest delay selected by the holder, which applies to counterparty-broadcast transactions
757 pub holder_selected_contest_delay: u16,
758 /// Whether the holder is the initiator of this channel.
759 /// This is an input to the commitment number obscure factor computation.
760 pub is_outbound_from_holder: bool,
761 /// The late-bound counterparty channel transaction parameters.
762 /// These parameters are populated at the point in the protocol where the counterparty provides them.
763 pub counterparty_parameters: Option<CounterpartyChannelTransactionParameters>,
764 /// The late-bound funding outpoint
765 pub funding_outpoint: Option<chain::transaction::OutPoint>,
766 /// Are anchors (zero fee HTLC transaction variant) used for this channel. Boolean is
767 /// serialization backwards-compatible.
768 pub opt_anchors: Option<()>
771 /// Late-bound per-channel counterparty data used to build transactions.
773 pub struct CounterpartyChannelTransactionParameters {
774 /// Counter-party public keys
775 pub pubkeys: ChannelPublicKeys,
776 /// The contest delay selected by the counterparty, which applies to holder-broadcast transactions
777 pub selected_contest_delay: u16,
780 impl ChannelTransactionParameters {
781 /// Whether the late bound parameters are populated.
782 pub fn is_populated(&self) -> bool {
783 self.counterparty_parameters.is_some() && self.funding_outpoint.is_some()
786 /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
787 /// given that the holder is the broadcaster.
789 /// self.is_populated() must be true before calling this function.
790 pub fn as_holder_broadcastable(&self) -> DirectedChannelTransactionParameters {
791 assert!(self.is_populated(), "self.late_parameters must be set before using as_holder_broadcastable");
792 DirectedChannelTransactionParameters {
794 holder_is_broadcaster: true
798 /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
799 /// given that the counterparty is the broadcaster.
801 /// self.is_populated() must be true before calling this function.
802 pub fn as_counterparty_broadcastable(&self) -> DirectedChannelTransactionParameters {
803 assert!(self.is_populated(), "self.late_parameters must be set before using as_counterparty_broadcastable");
804 DirectedChannelTransactionParameters {
806 holder_is_broadcaster: false
811 impl_writeable_tlv_based!(CounterpartyChannelTransactionParameters, {
812 (0, pubkeys, required),
813 (2, selected_contest_delay, required),
816 impl_writeable_tlv_based!(ChannelTransactionParameters, {
817 (0, holder_pubkeys, required),
818 (2, holder_selected_contest_delay, required),
819 (4, is_outbound_from_holder, required),
820 (6, counterparty_parameters, option),
821 (8, funding_outpoint, option),
822 (10, opt_anchors, option),
825 /// Static channel fields used to build transactions given per-commitment fields, organized by
826 /// broadcaster/countersignatory.
828 /// This is derived from the holder/counterparty-organized ChannelTransactionParameters via the
829 /// as_holder_broadcastable and as_counterparty_broadcastable functions.
830 pub struct DirectedChannelTransactionParameters<'a> {
831 /// The holder's channel static parameters
832 inner: &'a ChannelTransactionParameters,
833 /// Whether the holder is the broadcaster
834 holder_is_broadcaster: bool,
837 impl<'a> DirectedChannelTransactionParameters<'a> {
838 /// Get the channel pubkeys for the broadcaster
839 pub fn broadcaster_pubkeys(&self) -> &ChannelPublicKeys {
840 if self.holder_is_broadcaster {
841 &self.inner.holder_pubkeys
843 &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
847 /// Get the channel pubkeys for the countersignatory
848 pub fn countersignatory_pubkeys(&self) -> &ChannelPublicKeys {
849 if self.holder_is_broadcaster {
850 &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
852 &self.inner.holder_pubkeys
856 /// Get the contest delay applicable to the transactions.
857 /// Note that the contest delay was selected by the countersignatory.
858 pub fn contest_delay(&self) -> u16 {
859 let counterparty_parameters = self.inner.counterparty_parameters.as_ref().unwrap();
860 if self.holder_is_broadcaster { counterparty_parameters.selected_contest_delay } else { self.inner.holder_selected_contest_delay }
863 /// Whether the channel is outbound from the broadcaster.
865 /// The boolean representing the side that initiated the channel is
866 /// an input to the commitment number obscure factor computation.
867 pub fn is_outbound(&self) -> bool {
868 if self.holder_is_broadcaster { self.inner.is_outbound_from_holder } else { !self.inner.is_outbound_from_holder }
871 /// The funding outpoint
872 pub fn funding_outpoint(&self) -> OutPoint {
873 self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint()
876 /// Whether to use anchors for this channel
877 pub fn opt_anchors(&self) -> bool {
878 self.inner.opt_anchors.is_some()
882 /// Information needed to build and sign a holder's commitment transaction.
884 /// The transaction is only signed once we are ready to broadcast.
886 pub struct HolderCommitmentTransaction {
887 inner: CommitmentTransaction,
888 /// Our counterparty's signature for the transaction
889 pub counterparty_sig: Signature,
890 /// All non-dust counterparty HTLC signatures, in the order they appear in the transaction
891 pub counterparty_htlc_sigs: Vec<Signature>,
892 // Which order the signatures should go in when constructing the final commitment tx witness.
893 // The user should be able to reconstruct this themselves, so we don't bother to expose it.
894 holder_sig_first: bool,
897 impl Deref for HolderCommitmentTransaction {
898 type Target = CommitmentTransaction;
900 fn deref(&self) -> &Self::Target { &self.inner }
903 impl Eq for HolderCommitmentTransaction {}
904 impl PartialEq for HolderCommitmentTransaction {
905 // We dont care whether we are signed in equality comparison
906 fn eq(&self, o: &Self) -> bool {
907 self.inner == o.inner
911 impl_writeable_tlv_based!(HolderCommitmentTransaction, {
912 (0, inner, required),
913 (2, counterparty_sig, required),
914 (4, holder_sig_first, required),
915 (6, counterparty_htlc_sigs, vec_type),
918 impl HolderCommitmentTransaction {
920 pub fn dummy() -> Self {
921 let secp_ctx = Secp256k1::new();
922 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
923 let dummy_sig = sign(&secp_ctx, &secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
925 let keys = TxCreationKeys {
926 per_commitment_point: dummy_key.clone(),
927 revocation_key: dummy_key.clone(),
928 broadcaster_htlc_key: dummy_key.clone(),
929 countersignatory_htlc_key: dummy_key.clone(),
930 broadcaster_delayed_payment_key: dummy_key.clone(),
932 let channel_pubkeys = ChannelPublicKeys {
933 funding_pubkey: dummy_key.clone(),
934 revocation_basepoint: dummy_key.clone(),
935 payment_point: dummy_key.clone(),
936 delayed_payment_basepoint: dummy_key.clone(),
937 htlc_basepoint: dummy_key.clone()
939 let channel_parameters = ChannelTransactionParameters {
940 holder_pubkeys: channel_pubkeys.clone(),
941 holder_selected_contest_delay: 0,
942 is_outbound_from_holder: false,
943 counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }),
944 funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
947 let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
948 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());
949 HolderCommitmentTransaction {
951 counterparty_sig: dummy_sig,
952 counterparty_htlc_sigs: Vec::new(),
953 holder_sig_first: false
957 /// Create a new holder transaction with the given counterparty signatures.
958 /// The funding keys are used to figure out which signature should go first when building the transaction for broadcast.
959 pub fn new(commitment_tx: CommitmentTransaction, counterparty_sig: Signature, counterparty_htlc_sigs: Vec<Signature>, holder_funding_key: &PublicKey, counterparty_funding_key: &PublicKey) -> Self {
961 inner: commitment_tx,
963 counterparty_htlc_sigs,
964 holder_sig_first: holder_funding_key.serialize()[..] < counterparty_funding_key.serialize()[..],
968 pub(crate) fn add_holder_sig(&self, funding_redeemscript: &Script, holder_sig: Signature) -> Transaction {
969 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
970 let mut tx = self.inner.built.transaction.clone();
971 tx.input[0].witness.push(Vec::new());
972 let mut ser_holder_sig = holder_sig.serialize_der().to_vec();
973 ser_holder_sig.push(EcdsaSighashType::All as u8);
974 let mut ser_cp_sig = self.counterparty_sig.serialize_der().to_vec();
975 ser_cp_sig.push(EcdsaSighashType::All as u8);
977 if self.holder_sig_first {
978 tx.input[0].witness.push(ser_holder_sig);
979 tx.input[0].witness.push(ser_cp_sig);
981 tx.input[0].witness.push(ser_cp_sig);
982 tx.input[0].witness.push(ser_holder_sig);
985 tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
990 /// A pre-built Bitcoin commitment transaction and its txid.
992 pub struct BuiltCommitmentTransaction {
993 /// The commitment transaction
994 pub transaction: Transaction,
995 /// The txid for the commitment transaction.
997 /// This is provided as a performance optimization, instead of calling transaction.txid()
1002 impl_writeable_tlv_based!(BuiltCommitmentTransaction, {
1003 (0, transaction, required),
1004 (2, txid, required),
1007 impl BuiltCommitmentTransaction {
1008 /// Get the SIGHASH_ALL sighash value of the transaction.
1010 /// This can be used to verify a signature.
1011 pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1012 let sighash = &sighash::SighashCache::new(&self.transaction).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1013 hash_to_message!(sighash)
1016 /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
1017 /// because we are about to broadcast a holder transaction.
1018 pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1019 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1020 sign(secp_ctx, &sighash, funding_key)
1024 /// This class tracks the per-transaction information needed to build a closing transaction and will
1025 /// actually build it and sign.
1027 /// This class can be used inside a signer implementation to generate a signature given the relevant
1029 #[derive(Clone, Hash, PartialEq, Eq)]
1030 pub struct ClosingTransaction {
1031 to_holder_value_sat: u64,
1032 to_counterparty_value_sat: u64,
1033 to_holder_script: Script,
1034 to_counterparty_script: Script,
1038 impl ClosingTransaction {
1039 /// Construct an object of the class
1041 to_holder_value_sat: u64,
1042 to_counterparty_value_sat: u64,
1043 to_holder_script: Script,
1044 to_counterparty_script: Script,
1045 funding_outpoint: OutPoint,
1047 let built = build_closing_transaction(
1048 to_holder_value_sat, to_counterparty_value_sat,
1049 to_holder_script.clone(), to_counterparty_script.clone(),
1052 ClosingTransaction {
1053 to_holder_value_sat,
1054 to_counterparty_value_sat,
1056 to_counterparty_script,
1061 /// Trust our pre-built transaction.
1063 /// Applies a wrapper which allows access to the transaction.
1065 /// This should only be used if you fully trust the builder of this object. It should not
1066 /// be used by an external signer - instead use the verify function.
1067 pub fn trust(&self) -> TrustedClosingTransaction {
1068 TrustedClosingTransaction { inner: self }
1071 /// Verify our pre-built transaction.
1073 /// Applies a wrapper which allows access to the transaction.
1075 /// An external validating signer must call this method before signing
1076 /// or using the built transaction.
1077 pub fn verify(&self, funding_outpoint: OutPoint) -> Result<TrustedClosingTransaction, ()> {
1078 let built = build_closing_transaction(
1079 self.to_holder_value_sat, self.to_counterparty_value_sat,
1080 self.to_holder_script.clone(), self.to_counterparty_script.clone(),
1083 if self.built != built {
1086 Ok(TrustedClosingTransaction { inner: self })
1089 /// The value to be sent to the holder, or zero if the output will be omitted
1090 pub fn to_holder_value_sat(&self) -> u64 {
1091 self.to_holder_value_sat
1094 /// The value to be sent to the counterparty, or zero if the output will be omitted
1095 pub fn to_counterparty_value_sat(&self) -> u64 {
1096 self.to_counterparty_value_sat
1099 /// The destination of the holder's output
1100 pub fn to_holder_script(&self) -> &Script {
1101 &self.to_holder_script
1104 /// The destination of the counterparty's output
1105 pub fn to_counterparty_script(&self) -> &Script {
1106 &self.to_counterparty_script
1110 /// A wrapper on ClosingTransaction indicating that the built bitcoin
1111 /// transaction is trusted.
1113 /// See trust() and verify() functions on CommitmentTransaction.
1115 /// This structure implements Deref.
1116 pub struct TrustedClosingTransaction<'a> {
1117 inner: &'a ClosingTransaction,
1120 impl<'a> Deref for TrustedClosingTransaction<'a> {
1121 type Target = ClosingTransaction;
1123 fn deref(&self) -> &Self::Target { self.inner }
1126 impl<'a> TrustedClosingTransaction<'a> {
1127 /// The pre-built Bitcoin commitment transaction
1128 pub fn built_transaction(&self) -> &Transaction {
1132 /// Get the SIGHASH_ALL sighash value of the transaction.
1134 /// This can be used to verify a signature.
1135 pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1136 let sighash = &sighash::SighashCache::new(&self.inner.built).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1137 hash_to_message!(sighash)
1140 /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
1141 /// because we are about to broadcast a holder transaction.
1142 pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1143 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1144 sign(secp_ctx, &sighash, funding_key)
1148 /// This class tracks the per-transaction information needed to build a commitment transaction and will
1149 /// actually build it and sign. It is used for holder transactions that we sign only when needed
1150 /// and for transactions we sign for the counterparty.
1152 /// This class can be used inside a signer implementation to generate a signature given the relevant
1155 pub struct CommitmentTransaction {
1156 commitment_number: u64,
1157 to_broadcaster_value_sat: u64,
1158 to_countersignatory_value_sat: u64,
1159 feerate_per_kw: u32,
1160 htlcs: Vec<HTLCOutputInCommitment>,
1161 // A boolean that is serialization backwards-compatible
1162 opt_anchors: Option<()>,
1163 // A cache of the parties' pubkeys required to construct the transaction, see doc for trust()
1164 keys: TxCreationKeys,
1165 // For access to the pre-built transaction, see doc for trust()
1166 built: BuiltCommitmentTransaction,
1169 impl Eq for CommitmentTransaction {}
1170 impl PartialEq for CommitmentTransaction {
1171 fn eq(&self, o: &Self) -> bool {
1172 let eq = self.commitment_number == o.commitment_number &&
1173 self.to_broadcaster_value_sat == o.to_broadcaster_value_sat &&
1174 self.to_countersignatory_value_sat == o.to_countersignatory_value_sat &&
1175 self.feerate_per_kw == o.feerate_per_kw &&
1176 self.htlcs == o.htlcs &&
1177 self.opt_anchors == o.opt_anchors &&
1178 self.keys == o.keys;
1180 debug_assert_eq!(self.built.transaction, o.built.transaction);
1181 debug_assert_eq!(self.built.txid, o.built.txid);
1187 impl_writeable_tlv_based!(CommitmentTransaction, {
1188 (0, commitment_number, required),
1189 (2, to_broadcaster_value_sat, required),
1190 (4, to_countersignatory_value_sat, required),
1191 (6, feerate_per_kw, required),
1192 (8, keys, required),
1193 (10, built, required),
1194 (12, htlcs, vec_type),
1195 (14, opt_anchors, option),
1198 impl CommitmentTransaction {
1199 /// Construct an object of the class while assigning transaction output indices to HTLCs.
1201 /// Populates HTLCOutputInCommitment.transaction_output_index in htlcs_with_aux.
1203 /// The generic T allows the caller to match the HTLC output index with auxiliary data.
1204 /// This auxiliary data is not stored in this object.
1206 /// Only include HTLCs that are above the dust limit for the channel.
1208 /// (C-not exported) due to the generic though we likely should expose a version without
1209 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 {
1210 // Sort outputs and populate output indices while keeping track of the auxiliary data
1211 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();
1213 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(commitment_number, channel_parameters);
1214 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1215 let txid = transaction.txid();
1216 CommitmentTransaction {
1218 to_broadcaster_value_sat,
1219 to_countersignatory_value_sat,
1222 opt_anchors: if opt_anchors { Some(()) } else { None },
1224 built: BuiltCommitmentTransaction {
1231 fn internal_rebuild_transaction(&self, keys: &TxCreationKeys, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<BuiltCommitmentTransaction, ()> {
1232 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(self.commitment_number, channel_parameters);
1234 let mut htlcs_with_aux = self.htlcs.iter().map(|h| (h.clone(), ())).collect();
1235 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)?;
1237 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1238 let txid = transaction.txid();
1239 let built_transaction = BuiltCommitmentTransaction {
1243 Ok(built_transaction)
1246 fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec<TxIn>, outputs: Vec<TxOut>) -> Transaction {
1249 lock_time: PackedLockTime(((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32)),
1255 // This is used in two cases:
1256 // - initial sorting of outputs / HTLCs in the constructor, in which case T is auxiliary data the
1257 // caller needs to have sorted together with the HTLCs so it can keep track of the output index
1258 // - building of a bitcoin transaction during a verify() call, in which case T is just ()
1259 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>), ()> {
1260 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1261 let contest_delay = channel_parameters.contest_delay();
1263 let mut txouts: Vec<(TxOut, Option<&mut HTLCOutputInCommitment>)> = Vec::new();
1265 if to_countersignatory_value_sat > 0 {
1266 let script = if opt_anchors {
1267 get_to_countersignatory_with_anchors_redeemscript(&countersignatory_pubkeys.payment_point).to_v0_p2wsh()
1269 get_p2wpkh_redeemscript(&countersignatory_pubkeys.payment_point)
1273 script_pubkey: script.clone(),
1274 value: to_countersignatory_value_sat,
1280 if to_broadcaster_value_sat > 0 {
1281 let redeem_script = get_revokeable_redeemscript(
1282 &keys.revocation_key,
1284 &keys.broadcaster_delayed_payment_key,
1288 script_pubkey: redeem_script.to_v0_p2wsh(),
1289 value: to_broadcaster_value_sat,
1296 if to_broadcaster_value_sat > 0 || !htlcs_with_aux.is_empty() {
1297 let anchor_script = get_anchor_redeemscript(broadcaster_funding_key);
1300 script_pubkey: anchor_script.to_v0_p2wsh(),
1301 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1307 if to_countersignatory_value_sat > 0 || !htlcs_with_aux.is_empty() {
1308 let anchor_script = get_anchor_redeemscript(countersignatory_funding_key);
1311 script_pubkey: anchor_script.to_v0_p2wsh(),
1312 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1319 let mut htlcs = Vec::with_capacity(htlcs_with_aux.len());
1320 for (htlc, _) in htlcs_with_aux {
1321 let script = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys);
1323 script_pubkey: script.to_v0_p2wsh(),
1324 value: htlc.amount_msat / 1000,
1326 txouts.push((txout, Some(htlc)));
1329 // Sort output in BIP-69 order (amount, scriptPubkey). Tie-breaks based on HTLC
1330 // CLTV expiration height.
1331 sort_outputs(&mut txouts, |a, b| {
1332 if let &Some(ref a_htlcout) = a {
1333 if let &Some(ref b_htlcout) = b {
1334 a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
1335 // Note that due to hash collisions, we have to have a fallback comparison
1336 // here for fuzzing mode (otherwise at least chanmon_fail_consistency
1338 .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
1339 // For non-HTLC outputs, if they're copying our SPK we don't really care if we
1340 // close the channel due to mismatches - they're doing something dumb:
1341 } else { cmp::Ordering::Equal }
1342 } else { cmp::Ordering::Equal }
1345 let mut outputs = Vec::with_capacity(txouts.len());
1346 for (idx, out) in txouts.drain(..).enumerate() {
1347 if let Some(htlc) = out.1 {
1348 htlc.transaction_output_index = Some(idx as u32);
1349 htlcs.push(htlc.clone());
1351 outputs.push(out.0);
1353 Ok((outputs, htlcs))
1356 fn internal_build_inputs(commitment_number: u64, channel_parameters: &DirectedChannelTransactionParameters) -> (u64, Vec<TxIn>) {
1357 let broadcaster_pubkeys = channel_parameters.broadcaster_pubkeys();
1358 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1359 let commitment_transaction_number_obscure_factor = get_commitment_transaction_number_obscure_factor(
1360 &broadcaster_pubkeys.payment_point,
1361 &countersignatory_pubkeys.payment_point,
1362 channel_parameters.is_outbound(),
1365 let obscured_commitment_transaction_number =
1366 commitment_transaction_number_obscure_factor ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
1369 let mut ins: Vec<TxIn> = Vec::new();
1371 previous_output: channel_parameters.funding_outpoint(),
1372 script_sig: Script::new(),
1373 sequence: Sequence(((0x80 as u32) << 8 * 3)
1374 | ((obscured_commitment_transaction_number >> 3 * 8) as u32)),
1375 witness: Witness::new(),
1379 (obscured_commitment_transaction_number, txins)
1382 /// The backwards-counting commitment number
1383 pub fn commitment_number(&self) -> u64 {
1384 self.commitment_number
1387 /// The value to be sent to the broadcaster
1388 pub fn to_broadcaster_value_sat(&self) -> u64 {
1389 self.to_broadcaster_value_sat
1392 /// The value to be sent to the counterparty
1393 pub fn to_countersignatory_value_sat(&self) -> u64 {
1394 self.to_countersignatory_value_sat
1397 /// The feerate paid per 1000-weight-unit in this commitment transaction.
1398 pub fn feerate_per_kw(&self) -> u32 {
1402 /// The non-dust HTLCs (direction, amt, height expiration, hash, transaction output index)
1403 /// which were included in this commitment transaction in output order.
1404 /// The transaction index is always populated.
1406 /// (C-not exported) as we cannot currently convert Vec references to/from C, though we should
1407 /// expose a less effecient version which creates a Vec of references in the future.
1408 pub fn htlcs(&self) -> &Vec<HTLCOutputInCommitment> {
1412 /// Trust our pre-built transaction and derived transaction creation public keys.
1414 /// Applies a wrapper which allows access to these fields.
1416 /// This should only be used if you fully trust the builder of this object. It should not
1417 /// be used by an external signer - instead use the verify function.
1418 pub fn trust(&self) -> TrustedCommitmentTransaction {
1419 TrustedCommitmentTransaction { inner: self }
1422 /// Verify our pre-built transaction and derived transaction creation public keys.
1424 /// Applies a wrapper which allows access to these fields.
1426 /// An external validating signer must call this method before signing
1427 /// or using the built transaction.
1428 pub fn verify<T: secp256k1::Signing + secp256k1::Verification>(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TrustedCommitmentTransaction, ()> {
1429 // This is the only field of the key cache that we trust
1430 let per_commitment_point = self.keys.per_commitment_point;
1431 let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx).unwrap();
1432 if keys != self.keys {
1435 let tx = self.internal_rebuild_transaction(&keys, channel_parameters, &broadcaster_keys.funding_pubkey, &countersignatory_keys.funding_pubkey)?;
1436 if self.built.transaction != tx.transaction || self.built.txid != tx.txid {
1439 Ok(TrustedCommitmentTransaction { inner: self })
1443 /// A wrapper on CommitmentTransaction indicating that the derived fields (the built bitcoin
1444 /// transaction and the transaction creation keys) are trusted.
1446 /// See trust() and verify() functions on CommitmentTransaction.
1448 /// This structure implements Deref.
1449 pub struct TrustedCommitmentTransaction<'a> {
1450 inner: &'a CommitmentTransaction,
1453 impl<'a> Deref for TrustedCommitmentTransaction<'a> {
1454 type Target = CommitmentTransaction;
1456 fn deref(&self) -> &Self::Target { self.inner }
1459 impl<'a> TrustedCommitmentTransaction<'a> {
1460 /// The transaction ID of the built Bitcoin transaction
1461 pub fn txid(&self) -> Txid {
1462 self.inner.built.txid
1465 /// The pre-built Bitcoin commitment transaction
1466 pub fn built_transaction(&self) -> &BuiltCommitmentTransaction {
1470 /// The pre-calculated transaction creation public keys.
1471 pub fn keys(&self) -> &TxCreationKeys {
1475 /// Should anchors be used.
1476 pub fn opt_anchors(&self) -> bool {
1477 self.opt_anchors.is_some()
1480 /// Get a signature for each HTLC which was included in the commitment transaction (ie for
1481 /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
1483 /// The returned Vec has one entry for each HTLC, and in the same order.
1485 /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All.
1486 pub fn get_htlc_sigs<T: secp256k1::Signing>(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
1487 let inner = self.inner;
1488 let keys = &inner.keys;
1489 let txid = inner.built.txid;
1490 let mut ret = Vec::with_capacity(inner.htlcs.len());
1491 let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key).map_err(|_| ())?;
1493 for this_htlc in inner.htlcs.iter() {
1494 assert!(this_htlc.transaction_output_index.is_some());
1495 let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1497 let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
1499 let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]);
1500 ret.push(sign(secp_ctx, &sighash, &holder_htlc_key));
1505 /// Gets a signed HTLC transaction given a preimage (for !htlc.offered) and the holder HTLC transaction signature.
1506 pub(crate) fn get_signed_htlc_tx(&self, channel_parameters: &DirectedChannelTransactionParameters, htlc_index: usize, counterparty_signature: &Signature, signature: &Signature, preimage: &Option<PaymentPreimage>) -> Transaction {
1507 let inner = self.inner;
1508 let keys = &inner.keys;
1509 let txid = inner.built.txid;
1510 let this_htlc = &inner.htlcs[htlc_index];
1511 assert!(this_htlc.transaction_output_index.is_some());
1512 // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction.
1513 if !this_htlc.offered && preimage.is_none() { unreachable!(); }
1514 // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
1515 if this_htlc.offered && preimage.is_some() { unreachable!(); }
1517 let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1519 let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
1521 let sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
1523 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
1524 htlc_tx.input[0].witness.push(Vec::new());
1526 let mut cp_sig_ser = counterparty_signature.serialize_der().to_vec();
1527 cp_sig_ser.push(sighashtype as u8);
1528 htlc_tx.input[0].witness.push(cp_sig_ser);
1529 let mut holder_sig_ser = signature.serialize_der().to_vec();
1530 holder_sig_ser.push(EcdsaSighashType::All as u8);
1531 htlc_tx.input[0].witness.push(holder_sig_ser);
1533 if this_htlc.offered {
1534 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
1535 htlc_tx.input[0].witness.push(Vec::new());
1537 htlc_tx.input[0].witness.push(preimage.unwrap().0.to_vec());
1540 htlc_tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec());
1545 /// Commitment transaction numbers which appear in the transactions themselves are XOR'd with a
1546 /// shared secret first. This prevents on-chain observers from discovering how many commitment
1547 /// transactions occurred in a channel before it was closed.
1549 /// This function gets the shared secret from relevant channel public keys and can be used to
1550 /// "decrypt" the commitment transaction number given a commitment transaction on-chain.
1551 pub fn get_commitment_transaction_number_obscure_factor(
1552 broadcaster_payment_basepoint: &PublicKey,
1553 countersignatory_payment_basepoint: &PublicKey,
1554 outbound_from_broadcaster: bool,
1556 let mut sha = Sha256::engine();
1558 if outbound_from_broadcaster {
1559 sha.input(&broadcaster_payment_basepoint.serialize());
1560 sha.input(&countersignatory_payment_basepoint.serialize());
1562 sha.input(&countersignatory_payment_basepoint.serialize());
1563 sha.input(&broadcaster_payment_basepoint.serialize());
1565 let res = Sha256::from_engine(sha).into_inner();
1567 ((res[26] as u64) << 5 * 8)
1568 | ((res[27] as u64) << 4 * 8)
1569 | ((res[28] as u64) << 3 * 8)
1570 | ((res[29] as u64) << 2 * 8)
1571 | ((res[30] as u64) << 1 * 8)
1572 | ((res[31] as u64) << 0 * 8)
1575 fn get_p2wpkh_redeemscript(key: &PublicKey) -> Script {
1576 Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
1577 .push_slice(&WPubkeyHash::hash(&key.serialize())[..])
1583 use super::CounterpartyCommitmentSecrets;
1584 use crate::{hex, chain};
1585 use crate::prelude::*;
1586 use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, get_p2wpkh_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
1587 use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
1588 use crate::util::test_utils;
1589 use crate::chain::keysinterface::{KeysInterface, BaseSign};
1590 use bitcoin::{Network, Txid};
1591 use bitcoin::hashes::Hash;
1592 use crate::ln::PaymentHash;
1593 use bitcoin::hashes::hex::ToHex;
1597 let secp_ctx = Secp256k1::new();
1599 let seed = [42; 32];
1600 let network = Network::Testnet;
1601 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
1602 let signer = keys_provider.get_channel_signer(false, 3000);
1603 let counterparty_signer = keys_provider.get_channel_signer(false, 3000);
1604 let delayed_payment_base = &signer.pubkeys().delayed_payment_basepoint;
1605 let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
1606 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
1607 let htlc_basepoint = &signer.pubkeys().htlc_basepoint;
1608 let holder_pubkeys = signer.pubkeys();
1609 let counterparty_pubkeys = counterparty_signer.pubkeys();
1610 let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();
1611 let mut channel_parameters = ChannelTransactionParameters {
1612 holder_pubkeys: holder_pubkeys.clone(),
1613 holder_selected_contest_delay: 0,
1614 is_outbound_from_holder: false,
1615 counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }),
1616 funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
1620 let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
1622 // Generate broadcaster and counterparty outputs
1623 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1626 holder_pubkeys.funding_pubkey,
1627 counterparty_pubkeys.funding_pubkey,
1629 &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1631 assert_eq!(tx.built.transaction.output.len(), 2);
1632 assert_eq!(tx.built.transaction.output[1].script_pubkey, get_p2wpkh_redeemscript(&counterparty_pubkeys.payment_point));
1634 // Generate broadcaster and counterparty outputs as well as two anchors
1635 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1638 holder_pubkeys.funding_pubkey,
1639 counterparty_pubkeys.funding_pubkey,
1641 &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1643 assert_eq!(tx.built.transaction.output.len(), 4);
1644 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_to_countersignatory_with_anchors_redeemscript(&counterparty_pubkeys.payment_point).to_v0_p2wsh());
1646 // Generate broadcaster output and anchor
1647 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1650 holder_pubkeys.funding_pubkey,
1651 counterparty_pubkeys.funding_pubkey,
1653 &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1655 assert_eq!(tx.built.transaction.output.len(), 2);
1657 // Generate counterparty output and anchor
1658 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1661 holder_pubkeys.funding_pubkey,
1662 counterparty_pubkeys.funding_pubkey,
1664 &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1666 assert_eq!(tx.built.transaction.output.len(), 2);
1668 let received_htlc = HTLCOutputInCommitment {
1670 amount_msat: 400000,
1672 payment_hash: PaymentHash([42; 32]),
1673 transaction_output_index: None,
1676 let offered_htlc = HTLCOutputInCommitment {
1678 amount_msat: 600000,
1680 payment_hash: PaymentHash([43; 32]),
1681 transaction_output_index: None,
1684 // Generate broadcaster output and received and offered HTLC outputs, w/o anchors
1685 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1688 holder_pubkeys.funding_pubkey,
1689 counterparty_pubkeys.funding_pubkey,
1691 &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())],
1692 &channel_parameters.as_holder_broadcastable()
1694 assert_eq!(tx.built.transaction.output.len(), 3);
1695 assert_eq!(tx.built.transaction.output[0].script_pubkey, get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh());
1696 assert_eq!(tx.built.transaction.output[1].script_pubkey, get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh());
1697 assert_eq!(get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh().to_hex(),
1698 "002085cf52e41ba7c099a39df504e7b61f6de122971ceb53b06731876eaeb85e8dc5");
1699 assert_eq!(get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh().to_hex(),
1700 "002049f0736bb335c61a04d2623a24df878a7592a3c51fa7258d41b2c85318265e73");
1702 // Generate broadcaster output and received and offered HTLC outputs, with anchors
1703 channel_parameters.opt_anchors = Some(());
1704 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1707 holder_pubkeys.funding_pubkey,
1708 counterparty_pubkeys.funding_pubkey,
1710 &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())],
1711 &channel_parameters.as_holder_broadcastable()
1713 assert_eq!(tx.built.transaction.output.len(), 5);
1714 assert_eq!(tx.built.transaction.output[2].script_pubkey, get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh());
1715 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh());
1716 assert_eq!(get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh().to_hex(),
1717 "002067114123af3f95405bae4fd930fc95de03e3c86baaee8b2dd29b43dd26cf613c");
1718 assert_eq!(get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh().to_hex(),
1719 "0020a06e3b0d4fcf704f2b9c41e16a70099e39989466c3142b8573a1154542f28f57");
1723 fn test_per_commitment_storage() {
1724 // Test vectors from BOLT 3:
1725 let mut secrets: Vec<[u8; 32]> = Vec::new();
1728 macro_rules! test_secrets {
1730 let mut idx = 281474976710655;
1731 for secret in secrets.iter() {
1732 assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1735 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1736 assert!(monitor.get_secret(idx).is_none());
1741 // insert_secret correct sequence
1742 monitor = CounterpartyCommitmentSecrets::new();
1745 secrets.push([0; 32]);
1746 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1747 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1750 secrets.push([0; 32]);
1751 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1752 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1755 secrets.push([0; 32]);
1756 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1757 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1760 secrets.push([0; 32]);
1761 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1762 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1765 secrets.push([0; 32]);
1766 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1767 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1770 secrets.push([0; 32]);
1771 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1772 monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1775 secrets.push([0; 32]);
1776 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1777 monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1780 secrets.push([0; 32]);
1781 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1782 monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
1787 // insert_secret #1 incorrect
1788 monitor = CounterpartyCommitmentSecrets::new();
1791 secrets.push([0; 32]);
1792 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1793 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1796 secrets.push([0; 32]);
1797 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1798 assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err());
1802 // insert_secret #2 incorrect (#1 derived from incorrect)
1803 monitor = CounterpartyCommitmentSecrets::new();
1806 secrets.push([0; 32]);
1807 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1808 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1811 secrets.push([0; 32]);
1812 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1813 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1816 secrets.push([0; 32]);
1817 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1818 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1821 secrets.push([0; 32]);
1822 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1823 assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1827 // insert_secret #3 incorrect
1828 monitor = CounterpartyCommitmentSecrets::new();
1831 secrets.push([0; 32]);
1832 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1833 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1836 secrets.push([0; 32]);
1837 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1838 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1841 secrets.push([0; 32]);
1842 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1843 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1846 secrets.push([0; 32]);
1847 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1848 assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1852 // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1853 monitor = CounterpartyCommitmentSecrets::new();
1856 secrets.push([0; 32]);
1857 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1858 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1861 secrets.push([0; 32]);
1862 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1863 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1866 secrets.push([0; 32]);
1867 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1868 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1871 secrets.push([0; 32]);
1872 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1873 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1876 secrets.push([0; 32]);
1877 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1878 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1881 secrets.push([0; 32]);
1882 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1883 monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1886 secrets.push([0; 32]);
1887 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1888 monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1891 secrets.push([0; 32]);
1892 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1893 assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1897 // insert_secret #5 incorrect
1898 monitor = CounterpartyCommitmentSecrets::new();
1901 secrets.push([0; 32]);
1902 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1903 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1906 secrets.push([0; 32]);
1907 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1908 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1911 secrets.push([0; 32]);
1912 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1913 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1916 secrets.push([0; 32]);
1917 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1918 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1921 secrets.push([0; 32]);
1922 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1923 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1926 secrets.push([0; 32]);
1927 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1928 assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err());
1932 // insert_secret #6 incorrect (5 derived from incorrect)
1933 monitor = CounterpartyCommitmentSecrets::new();
1936 secrets.push([0; 32]);
1937 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1938 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1941 secrets.push([0; 32]);
1942 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1943 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1946 secrets.push([0; 32]);
1947 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1948 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1951 secrets.push([0; 32]);
1952 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1953 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1956 secrets.push([0; 32]);
1957 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1958 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1961 secrets.push([0; 32]);
1962 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
1963 monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1966 secrets.push([0; 32]);
1967 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1968 monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1971 secrets.push([0; 32]);
1972 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1973 assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1977 // insert_secret #7 incorrect
1978 monitor = CounterpartyCommitmentSecrets::new();
1981 secrets.push([0; 32]);
1982 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1983 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1986 secrets.push([0; 32]);
1987 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1988 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1991 secrets.push([0; 32]);
1992 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1993 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1996 secrets.push([0; 32]);
1997 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1998 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2001 secrets.push([0; 32]);
2002 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2003 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2006 secrets.push([0; 32]);
2007 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2008 monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2011 secrets.push([0; 32]);
2012 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
2013 monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2016 secrets.push([0; 32]);
2017 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2018 assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2022 // insert_secret #8 incorrect
2023 monitor = CounterpartyCommitmentSecrets::new();
2026 secrets.push([0; 32]);
2027 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2028 monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2031 secrets.push([0; 32]);
2032 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2033 monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2036 secrets.push([0; 32]);
2037 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2038 monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2041 secrets.push([0; 32]);
2042 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2043 monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2046 secrets.push([0; 32]);
2047 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2048 monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2051 secrets.push([0; 32]);
2052 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2053 monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2056 secrets.push([0; 32]);
2057 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2058 monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2061 secrets.push([0; 32]);
2062 secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
2063 assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());