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[rust-lightning] / 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 the traits on [`chain::keysinterface`] by hand.
12
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;
17 use bitcoin::util::address::Payload;
18
19 use bitcoin::hashes::{Hash, HashEngine};
20 use bitcoin::hashes::sha256::Hash as Sha256;
21 use bitcoin::hashes::ripemd160::Hash as Ripemd160;
22 use bitcoin::hash_types::{Txid, PubkeyHash};
23
24 use crate::ln::{PaymentHash, PaymentPreimage};
25 use crate::ln::msgs::DecodeError;
26 use crate::util::ser::{Readable, Writeable, Writer};
27 use crate::util::transaction_utils;
28
29 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
30 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
31 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
32 use bitcoin::PublicKey as BitcoinPublicKey;
33
34 use crate::io;
35 use crate::prelude::*;
36 use core::cmp;
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};
40 use core::ops::Deref;
41 use crate::chain;
42 use crate::util::crypto::sign;
43
44 /// Maximum number of one-way in-flight HTLC (protocol-level value).
45 pub const MAX_HTLCS: u16 = 483;
46 /// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, non-anchor variant.
47 pub const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
48 /// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, anchor variant.
49 pub const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136;
50
51 /// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value.
52 /// We define a range that encompasses both its non-anchors and anchors variants.
53 pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136;
54 /// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value.
55 /// We define a range that encompasses both its non-anchors and anchors variants.
56 /// This is the maximum post-anchor value.
57 pub const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
58
59 /// Gets the weight for an HTLC-Success transaction.
60 #[inline]
61 pub fn htlc_success_tx_weight(opt_anchors: bool) -> u64 {
62         const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
63         const HTLC_SUCCESS_ANCHOR_TX_WEIGHT: u64 = 706;
64         if opt_anchors { HTLC_SUCCESS_ANCHOR_TX_WEIGHT } else { HTLC_SUCCESS_TX_WEIGHT }
65 }
66
67 /// Gets the weight for an HTLC-Timeout transaction.
68 #[inline]
69 pub fn htlc_timeout_tx_weight(opt_anchors: bool) -> u64 {
70         const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
71         const HTLC_TIMEOUT_ANCHOR_TX_WEIGHT: u64 = 666;
72         if opt_anchors { HTLC_TIMEOUT_ANCHOR_TX_WEIGHT } else { HTLC_TIMEOUT_TX_WEIGHT }
73 }
74
75 /// Describes the type of HTLC claim as determined by analyzing the witness.
76 #[derive(PartialEq, Eq)]
77 pub enum HTLCClaim {
78         /// Claims an offered output on a commitment transaction through the timeout path.
79         OfferedTimeout,
80         /// Claims an offered output on a commitment transaction through the success path.
81         OfferedPreimage,
82         /// Claims an accepted output on a commitment transaction through the timeout path.
83         AcceptedTimeout,
84         /// Claims an accepted output on a commitment transaction through the success path.
85         AcceptedPreimage,
86         /// Claims an offered/accepted output on a commitment transaction through the revocation path.
87         Revocation,
88 }
89
90 impl HTLCClaim {
91         /// Check if a given input witness attempts to claim a HTLC.
92         pub fn from_witness(witness: &Witness) -> Option<Self> {
93                 debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT);
94                 if witness.len() < 2 {
95                         return None;
96                 }
97                 let witness_script = witness.last().unwrap();
98                 let second_to_last = witness.second_to_last().unwrap();
99                 if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT {
100                         if witness.len() == 3 && second_to_last.len() == 33 {
101                                 // <revocation sig> <revocationpubkey> <witness_script>
102                                 Some(Self::Revocation)
103                         } else if witness.len() == 3 && second_to_last.len() == 32 {
104                                 // <remotehtlcsig> <payment_preimage> <witness_script>
105                                 Some(Self::OfferedPreimage)
106                         } else if witness.len() == 5 && second_to_last.len() == 0 {
107                                 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
108                                 Some(Self::OfferedTimeout)
109                         } else {
110                                 None
111                         }
112                 } else if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS {
113                         // It's possible for the weight of `offered_htlc_script` and `accepted_htlc_script` to
114                         // match so we check for both here.
115                         if witness.len() == 3 && second_to_last.len() == 33 {
116                                 // <revocation sig> <revocationpubkey> <witness_script>
117                                 Some(Self::Revocation)
118                         } else if witness.len() == 3 && second_to_last.len() == 32 {
119                                 // <remotehtlcsig> <payment_preimage> <witness_script>
120                                 Some(Self::OfferedPreimage)
121                         } else if witness.len() == 5 && second_to_last.len() == 0 {
122                                 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
123                                 Some(Self::OfferedTimeout)
124                         } else if witness.len() == 3 && second_to_last.len() == 0 {
125                                 // <remotehtlcsig> <> <witness_script>
126                                 Some(Self::AcceptedTimeout)
127                         } else if witness.len() == 5 && second_to_last.len() == 32 {
128                                 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
129                                 Some(Self::AcceptedPreimage)
130                         } else {
131                                 None
132                         }
133                 } else if witness_script.len() > MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT &&
134                         witness_script.len() <= MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT {
135                         // Handle remaining range of ACCEPTED_HTLC_SCRIPT_WEIGHT.
136                         if witness.len() == 3 && second_to_last.len() == 33 {
137                                 // <revocation sig> <revocationpubkey> <witness_script>
138                                 Some(Self::Revocation)
139                         } else if witness.len() == 3 && second_to_last.len() == 0 {
140                                 // <remotehtlcsig> <> <witness_script>
141                                 Some(Self::AcceptedTimeout)
142                         } else if witness.len() == 5 && second_to_last.len() == 32 {
143                                 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
144                                 Some(Self::AcceptedPreimage)
145                         } else {
146                                 None
147                         }
148                 } else {
149                         None
150                 }
151         }
152 }
153
154 // Various functions for key derivation and transaction creation for use within channels. Primarily
155 // used in Channel and ChannelMonitor.
156
157 /// Build the commitment secret from the seed and the commitment number
158 pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] {
159         let mut res: [u8; 32] = commitment_seed.clone();
160         for i in 0..48 {
161                 let bitpos = 47 - i;
162                 if idx & (1 << bitpos) == (1 << bitpos) {
163                         res[bitpos / 8] ^= 1 << (bitpos & 7);
164                         res = Sha256::hash(&res).into_inner();
165                 }
166         }
167         res
168 }
169
170 /// Build a closing transaction
171 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 {
172         let txins = {
173                 let mut ins: Vec<TxIn> = Vec::new();
174                 ins.push(TxIn {
175                         previous_output: funding_outpoint,
176                         script_sig: Script::new(),
177                         sequence: Sequence::MAX,
178                         witness: Witness::new(),
179                 });
180                 ins
181         };
182
183         let mut txouts: Vec<(TxOut, ())> = Vec::new();
184
185         if to_counterparty_value_sat > 0 {
186                 txouts.push((TxOut {
187                         script_pubkey: to_counterparty_script,
188                         value: to_counterparty_value_sat
189                 }, ()));
190         }
191
192         if to_holder_value_sat > 0 {
193                 txouts.push((TxOut {
194                         script_pubkey: to_holder_script,
195                         value: to_holder_value_sat
196                 }, ()));
197         }
198
199         transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
200
201         let mut outputs: Vec<TxOut> = Vec::new();
202         for out in txouts.drain(..) {
203                 outputs.push(out.0);
204         }
205
206         Transaction {
207                 version: 2,
208                 lock_time: PackedLockTime::ZERO,
209                 input: txins,
210                 output: outputs,
211         }
212 }
213
214 /// Implements the per-commitment secret storage scheme from
215 /// [BOLT 3](https://github.com/lightning/bolts/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
216 ///
217 /// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes
218 /// or so.
219 #[derive(Clone)]
220 pub struct CounterpartyCommitmentSecrets {
221         old_secrets: [([u8; 32], u64); 49],
222 }
223
224 impl Eq for CounterpartyCommitmentSecrets {}
225 impl PartialEq for CounterpartyCommitmentSecrets {
226         fn eq(&self, other: &Self) -> bool {
227                 for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
228                         if secret != o_secret || idx != o_idx {
229                                 return false
230                         }
231                 }
232                 true
233         }
234 }
235
236 impl CounterpartyCommitmentSecrets {
237         /// Creates a new empty `CounterpartyCommitmentSecrets` structure.
238         pub fn new() -> Self {
239                 Self { old_secrets: [([0; 32], 1 << 48); 49], }
240         }
241
242         #[inline]
243         fn place_secret(idx: u64) -> u8 {
244                 for i in 0..48 {
245                         if idx & (1 << i) == (1 << i) {
246                                 return i
247                         }
248                 }
249                 48
250         }
251
252         /// Returns the minimum index of all stored secrets. Note that indexes start
253         /// at 1 << 48 and get decremented by one for each new secret.
254         pub fn get_min_seen_secret(&self) -> u64 {
255                 //TODO This can be optimized?
256                 let mut min = 1 << 48;
257                 for &(_, idx) in self.old_secrets.iter() {
258                         if idx < min {
259                                 min = idx;
260                         }
261                 }
262                 min
263         }
264
265         #[inline]
266         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
267                 let mut res: [u8; 32] = secret;
268                 for i in 0..bits {
269                         let bitpos = bits - 1 - i;
270                         if idx & (1 << bitpos) == (1 << bitpos) {
271                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
272                                 res = Sha256::hash(&res).into_inner();
273                         }
274                 }
275                 res
276         }
277
278         /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret
279         /// was generated in accordance with BOLT 3 and is consistent with previous secrets.
280         pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
281                 let pos = Self::place_secret(idx);
282                 for i in 0..pos {
283                         let (old_secret, old_idx) = self.old_secrets[i as usize];
284                         if Self::derive_secret(secret, pos, old_idx) != old_secret {
285                                 return Err(());
286                         }
287                 }
288                 if self.get_min_seen_secret() <= idx {
289                         return Ok(());
290                 }
291                 self.old_secrets[pos as usize] = (secret, idx);
292                 Ok(())
293         }
294
295         /// Returns the secret at `idx`.
296         /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`].
297         pub fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
298                 for i in 0..self.old_secrets.len() {
299                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
300                                 return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
301                         }
302                 }
303                 assert!(idx < self.get_min_seen_secret());
304                 None
305         }
306 }
307
308 impl Writeable for CounterpartyCommitmentSecrets {
309         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
310                 for &(ref secret, ref idx) in self.old_secrets.iter() {
311                         writer.write_all(secret)?;
312                         writer.write_all(&idx.to_be_bytes())?;
313                 }
314                 write_tlv_fields!(writer, {});
315                 Ok(())
316         }
317 }
318 impl Readable for CounterpartyCommitmentSecrets {
319         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
320                 let mut old_secrets = [([0; 32], 1 << 48); 49];
321                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
322                         *secret = Readable::read(reader)?;
323                         *idx = Readable::read(reader)?;
324                 }
325                 read_tlv_fields!(reader, {});
326                 Ok(Self { old_secrets })
327         }
328 }
329
330 /// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
331 /// from the base secret and the per_commitment_point.
332 pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> SecretKey {
333         let mut sha = Sha256::engine();
334         sha.input(&per_commitment_point.serialize());
335         sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
336         let res = Sha256::from_engine(sha).into_inner();
337
338         base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap())
339                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
340 }
341
342 /// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
343 /// from the base point and the per_commitment_key. This is the public equivalent of
344 /// derive_private_key - using only public keys to derive a public key instead of private keys.
345 pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> PublicKey {
346         let mut sha = Sha256::engine();
347         sha.input(&per_commitment_point.serialize());
348         sha.input(&base_point.serialize());
349         let res = Sha256::from_engine(sha).into_inner();
350
351         let hashkey = PublicKey::from_secret_key(&secp_ctx,
352                 &SecretKey::from_slice(&res).expect("Hashes should always be valid keys unless SHA-256 is broken"));
353         base_point.combine(&hashkey)
354                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
355 }
356
357 /// Derives a per-commitment-transaction revocation key from its constituent parts.
358 ///
359 /// Only the cheating participant owns a valid witness to propagate a revoked
360 /// commitment transaction, thus per_commitment_secret always come from cheater
361 /// and revocation_base_secret always come from punisher, which is the broadcaster
362 /// of the transaction spending with this key knowledge.
363 pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>,
364         per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey)
365 -> SecretKey {
366         let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret);
367         let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
368
369         let rev_append_commit_hash_key = {
370                 let mut sha = Sha256::engine();
371                 sha.input(&countersignatory_revocation_base_point.serialize());
372                 sha.input(&per_commitment_point.serialize());
373
374                 Sha256::from_engine(sha).into_inner()
375         };
376         let commit_append_rev_hash_key = {
377                 let mut sha = Sha256::engine();
378                 sha.input(&per_commitment_point.serialize());
379                 sha.input(&countersignatory_revocation_base_point.serialize());
380
381                 Sha256::from_engine(sha).into_inner()
382         };
383
384         let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
385                 .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
386         let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
387                 .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
388         countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap())
389                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
390 }
391
392 /// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
393 /// the public equivalend of derive_private_revocation_key - using only public keys to derive a
394 /// public key instead of private keys.
395 ///
396 /// Only the cheating participant owns a valid witness to propagate a revoked
397 /// commitment transaction, thus per_commitment_point always come from cheater
398 /// and revocation_base_point always come from punisher, which is the broadcaster
399 /// of the transaction spending with this key knowledge.
400 ///
401 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
402 /// generated (ie our own).
403 pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>,
404         per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey)
405 -> PublicKey {
406         let rev_append_commit_hash_key = {
407                 let mut sha = Sha256::engine();
408                 sha.input(&countersignatory_revocation_base_point.serialize());
409                 sha.input(&per_commitment_point.serialize());
410
411                 Sha256::from_engine(sha).into_inner()
412         };
413         let commit_append_rev_hash_key = {
414                 let mut sha = Sha256::engine();
415                 sha.input(&per_commitment_point.serialize());
416                 sha.input(&countersignatory_revocation_base_point.serialize());
417
418                 Sha256::from_engine(sha).into_inner()
419         };
420
421         let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
422                 .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
423         let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
424                 .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
425         countersignatory_contrib.combine(&broadcaster_contrib)
426                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
427 }
428
429 /// The set of public keys which are used in the creation of one commitment transaction.
430 /// These are derived from the channel base keys and per-commitment data.
431 ///
432 /// A broadcaster key is provided from potential broadcaster of the computed transaction.
433 /// A countersignatory key is coming from a protocol participant unable to broadcast the
434 /// transaction.
435 ///
436 /// These keys are assumed to be good, either because the code derived them from
437 /// channel basepoints via the new function, or they were obtained via
438 /// CommitmentTransaction.trust().keys() because we trusted the source of the
439 /// pre-calculated keys.
440 #[derive(PartialEq, Eq, Clone)]
441 pub struct TxCreationKeys {
442         /// The broadcaster's per-commitment public key which was used to derive the other keys.
443         pub per_commitment_point: PublicKey,
444         /// The revocation key which is used to allow the broadcaster of the commitment
445         /// transaction to provide their counterparty the ability to punish them if they broadcast
446         /// an old state.
447         pub revocation_key: PublicKey,
448         /// Broadcaster's HTLC Key
449         pub broadcaster_htlc_key: PublicKey,
450         /// Countersignatory's HTLC Key
451         pub countersignatory_htlc_key: PublicKey,
452         /// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay)
453         pub broadcaster_delayed_payment_key: PublicKey,
454 }
455
456 impl_writeable_tlv_based!(TxCreationKeys, {
457         (0, per_commitment_point, required),
458         (2, revocation_key, required),
459         (4, broadcaster_htlc_key, required),
460         (6, countersignatory_htlc_key, required),
461         (8, broadcaster_delayed_payment_key, required),
462 });
463
464 /// One counterparty's public keys which do not change over the life of a channel.
465 #[derive(Clone, Debug, PartialEq, Eq)]
466 pub struct ChannelPublicKeys {
467         /// The public key which is used to sign all commitment transactions, as it appears in the
468         /// on-chain channel lock-in 2-of-2 multisig output.
469         pub funding_pubkey: PublicKey,
470         /// The base point which is used (with derive_public_revocation_key) to derive per-commitment
471         /// revocation keys. This is combined with the per-commitment-secret generated by the
472         /// counterparty to create a secret which the counterparty can reveal to revoke previous
473         /// states.
474         pub revocation_basepoint: PublicKey,
475         /// The public key on which the non-broadcaster (ie the countersignatory) receives an immediately
476         /// spendable primary channel balance on the broadcaster's commitment transaction. This key is
477         /// static across every commitment transaction.
478         pub payment_point: PublicKey,
479         /// The base point which is used (with derive_public_key) to derive a per-commitment payment
480         /// public key which receives non-HTLC-encumbered funds which are only available for spending
481         /// after some delay (or can be claimed via the revocation path).
482         pub delayed_payment_basepoint: PublicKey,
483         /// The base point which is used (with derive_public_key) to derive a per-commitment public key
484         /// which is used to encumber HTLC-in-flight outputs.
485         pub htlc_basepoint: PublicKey,
486 }
487
488 impl_writeable_tlv_based!(ChannelPublicKeys, {
489         (0, funding_pubkey, required),
490         (2, revocation_basepoint, required),
491         (4, payment_point, required),
492         (6, delayed_payment_basepoint, required),
493         (8, htlc_basepoint, required),
494 });
495
496 impl TxCreationKeys {
497         /// Create per-state keys from channel base points and the per-commitment point.
498         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
499         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) -> TxCreationKeys {
500                 TxCreationKeys {
501                         per_commitment_point: per_commitment_point.clone(),
502                         revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base),
503                         broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base),
504                         countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base),
505                         broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base),
506                 }
507         }
508
509         /// Generate per-state keys from channel static keys.
510         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
511         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>) -> TxCreationKeys {
512                 TxCreationKeys::derive_new(
513                         &secp_ctx,
514                         &per_commitment_point,
515                         &broadcaster_keys.delayed_payment_basepoint,
516                         &broadcaster_keys.htlc_basepoint,
517                         &countersignatory_keys.revocation_basepoint,
518                         &countersignatory_keys.htlc_basepoint,
519                 )
520         }
521 }
522
523 /// The maximum length of a script returned by get_revokeable_redeemscript.
524 // Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public
525 // keys of 33 bytes (+ 1 push).
526 pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2;
527
528 /// A script either spendable by the revocation
529 /// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
530 /// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions.
531 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> Script {
532         let res = Builder::new().push_opcode(opcodes::all::OP_IF)
533                       .push_slice(&revocation_key.serialize())
534                       .push_opcode(opcodes::all::OP_ELSE)
535                       .push_int(contest_delay as i64)
536                       .push_opcode(opcodes::all::OP_CSV)
537                       .push_opcode(opcodes::all::OP_DROP)
538                       .push_slice(&broadcaster_delayed_payment_key.serialize())
539                       .push_opcode(opcodes::all::OP_ENDIF)
540                       .push_opcode(opcodes::all::OP_CHECKSIG)
541                       .into_script();
542         debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH);
543         res
544 }
545
546 /// Information about an HTLC as it appears in a commitment transaction
547 #[derive(Clone, Debug, PartialEq, Eq)]
548 pub struct HTLCOutputInCommitment {
549         /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
550         /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
551         /// need to compare this value to whether the commitment transaction in question is that of
552         /// the counterparty or our own.
553         pub offered: bool,
554         /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is
555         /// this divided by 1000.
556         pub amount_msat: u64,
557         /// The CLTV lock-time at which this HTLC expires.
558         pub cltv_expiry: u32,
559         /// The hash of the preimage which unlocks this HTLC.
560         pub payment_hash: PaymentHash,
561         /// The position within the commitment transactions' outputs. This may be None if the value is
562         /// below the dust limit (in which case no output appears in the commitment transaction and the
563         /// value is spent to additional transaction fees).
564         pub transaction_output_index: Option<u32>,
565 }
566
567 impl_writeable_tlv_based!(HTLCOutputInCommitment, {
568         (0, offered, required),
569         (2, amount_msat, required),
570         (4, cltv_expiry, required),
571         (6, payment_hash, required),
572         (8, transaction_output_index, option),
573 });
574
575 #[inline]
576 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 {
577         let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner();
578         if htlc.offered {
579                 let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
580                               .push_opcode(opcodes::all::OP_HASH160)
581                               .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
582                               .push_opcode(opcodes::all::OP_EQUAL)
583                               .push_opcode(opcodes::all::OP_IF)
584                               .push_opcode(opcodes::all::OP_CHECKSIG)
585                               .push_opcode(opcodes::all::OP_ELSE)
586                               .push_slice(&countersignatory_htlc_key.serialize()[..])
587                               .push_opcode(opcodes::all::OP_SWAP)
588                               .push_opcode(opcodes::all::OP_SIZE)
589                               .push_int(32)
590                               .push_opcode(opcodes::all::OP_EQUAL)
591                               .push_opcode(opcodes::all::OP_NOTIF)
592                               .push_opcode(opcodes::all::OP_DROP)
593                               .push_int(2)
594                               .push_opcode(opcodes::all::OP_SWAP)
595                               .push_slice(&broadcaster_htlc_key.serialize()[..])
596                               .push_int(2)
597                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
598                               .push_opcode(opcodes::all::OP_ELSE)
599                               .push_opcode(opcodes::all::OP_HASH160)
600                               .push_slice(&payment_hash160)
601                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
602                               .push_opcode(opcodes::all::OP_CHECKSIG)
603                               .push_opcode(opcodes::all::OP_ENDIF);
604                 if opt_anchors {
605                         bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
606                                 .push_opcode(opcodes::all::OP_CSV)
607                                 .push_opcode(opcodes::all::OP_DROP);
608                 }
609                 bldr.push_opcode(opcodes::all::OP_ENDIF)
610                         .into_script()
611         } else {
612                         let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
613                               .push_opcode(opcodes::all::OP_HASH160)
614                               .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..])
615                               .push_opcode(opcodes::all::OP_EQUAL)
616                               .push_opcode(opcodes::all::OP_IF)
617                               .push_opcode(opcodes::all::OP_CHECKSIG)
618                               .push_opcode(opcodes::all::OP_ELSE)
619                               .push_slice(&countersignatory_htlc_key.serialize()[..])
620                               .push_opcode(opcodes::all::OP_SWAP)
621                               .push_opcode(opcodes::all::OP_SIZE)
622                               .push_int(32)
623                               .push_opcode(opcodes::all::OP_EQUAL)
624                               .push_opcode(opcodes::all::OP_IF)
625                               .push_opcode(opcodes::all::OP_HASH160)
626                               .push_slice(&payment_hash160)
627                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
628                               .push_int(2)
629                               .push_opcode(opcodes::all::OP_SWAP)
630                               .push_slice(&broadcaster_htlc_key.serialize()[..])
631                               .push_int(2)
632                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
633                               .push_opcode(opcodes::all::OP_ELSE)
634                               .push_opcode(opcodes::all::OP_DROP)
635                               .push_int(htlc.cltv_expiry as i64)
636                               .push_opcode(opcodes::all::OP_CLTV)
637                               .push_opcode(opcodes::all::OP_DROP)
638                               .push_opcode(opcodes::all::OP_CHECKSIG)
639                               .push_opcode(opcodes::all::OP_ENDIF);
640                 if opt_anchors {
641                         bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
642                                 .push_opcode(opcodes::all::OP_CSV)
643                                 .push_opcode(opcodes::all::OP_DROP);
644                 }
645                 bldr.push_opcode(opcodes::all::OP_ENDIF)
646                         .into_script()
647         }
648 }
649
650 /// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc
651 /// does not need to have its previous_output_index filled.
652 #[inline]
653 pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, opt_anchors: bool, keys: &TxCreationKeys) -> Script {
654         get_htlc_redeemscript_with_explicit_keys(htlc, opt_anchors, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key)
655 }
656
657 /// Gets the redeemscript for a funding output from the two funding public keys.
658 /// Note that the order of funding public keys does not matter.
659 pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &PublicKey) -> Script {
660         let broadcaster_funding_key = broadcaster.serialize();
661         let countersignatory_funding_key = countersignatory.serialize();
662
663         make_funding_redeemscript_from_slices(&broadcaster_funding_key, &countersignatory_funding_key)
664 }
665
666 pub(crate) fn make_funding_redeemscript_from_slices(broadcaster_funding_key: &[u8], countersignatory_funding_key: &[u8]) -> Script {
667         let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
668         if broadcaster_funding_key[..] < countersignatory_funding_key[..] {
669                 builder.push_slice(broadcaster_funding_key)
670                         .push_slice(countersignatory_funding_key)
671         } else {
672                 builder.push_slice(countersignatory_funding_key)
673                         .push_slice(broadcaster_funding_key)
674         }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
675 }
676
677 /// Builds an unsigned HTLC-Success or HTLC-Timeout transaction from the given channel and HTLC
678 /// parameters. This is used by [`TrustedCommitmentTransaction::get_htlc_sigs`] to fetch the
679 /// transaction which needs signing, and can be used to construct an HTLC transaction which is
680 /// broadcastable given a counterparty HTLC signature.
681 ///
682 /// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the
683 /// commitment transaction).
684 pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool, use_non_zero_fee_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
685         let mut txins: Vec<TxIn> = Vec::new();
686         txins.push(build_htlc_input(commitment_txid, htlc, opt_anchors));
687
688         let mut txouts: Vec<TxOut> = Vec::new();
689         txouts.push(build_htlc_output(
690                 feerate_per_kw, contest_delay, htlc, opt_anchors, use_non_zero_fee_anchors,
691                 broadcaster_delayed_payment_key, revocation_key
692         ));
693
694         Transaction {
695                 version: 2,
696                 lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }),
697                 input: txins,
698                 output: txouts,
699         }
700 }
701
702 pub(crate) fn build_htlc_input(commitment_txid: &Txid, htlc: &HTLCOutputInCommitment, opt_anchors: bool) -> TxIn {
703         TxIn {
704                 previous_output: OutPoint {
705                         txid: commitment_txid.clone(),
706                         vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
707                 },
708                 script_sig: Script::new(),
709                 sequence: Sequence(if opt_anchors { 1 } else { 0 }),
710                 witness: Witness::new(),
711         }
712 }
713
714 pub(crate) fn build_htlc_output(
715         feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool,
716         use_non_zero_fee_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey
717 ) -> TxOut {
718         let weight = if htlc.offered {
719                 htlc_timeout_tx_weight(opt_anchors)
720         } else {
721                 htlc_success_tx_weight(opt_anchors)
722         };
723         let output_value = if opt_anchors && !use_non_zero_fee_anchors {
724                 htlc.amount_msat / 1000
725         } else {
726                 let total_fee = feerate_per_kw as u64 * weight / 1000;
727                 htlc.amount_msat / 1000 - total_fee
728         };
729
730         TxOut {
731                 script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
732                 value: output_value,
733         }
734 }
735
736 /// Returns the witness required to satisfy and spend a HTLC input.
737 pub fn build_htlc_input_witness(
738         local_sig: &Signature, remote_sig: &Signature, preimage: &Option<PaymentPreimage>,
739         redeem_script: &Script, opt_anchors: bool,
740 ) -> Witness {
741         let remote_sighash_type = if opt_anchors {
742                 EcdsaSighashType::SinglePlusAnyoneCanPay
743         } else {
744                 EcdsaSighashType::All
745         };
746
747         let mut witness = Witness::new();
748         // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
749         witness.push(vec![]);
750         witness.push_bitcoin_signature(&remote_sig.serialize_der(), remote_sighash_type);
751         witness.push_bitcoin_signature(&local_sig.serialize_der(), EcdsaSighashType::All);
752         if let Some(preimage) = preimage {
753                 witness.push(preimage.0.to_vec());
754         } else {
755                 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
756                 witness.push(vec![]);
757         }
758         witness.push(redeem_script.to_bytes());
759         witness
760 }
761
762 /// Gets the witnessScript for the to_remote output when anchors are enabled.
763 #[inline]
764 pub fn get_to_countersignatory_with_anchors_redeemscript(payment_point: &PublicKey) -> Script {
765         Builder::new()
766                 .push_slice(&payment_point.serialize()[..])
767                 .push_opcode(opcodes::all::OP_CHECKSIGVERIFY)
768                 .push_int(1)
769                 .push_opcode(opcodes::all::OP_CSV)
770                 .into_script()
771 }
772
773 /// Gets the witnessScript for an anchor output from the funding public key.
774 /// The witness in the spending input must be:
775 /// <BIP 143 funding_signature>
776 /// After 16 blocks of confirmation, an alternative satisfying witness could be:
777 /// <>
778 /// (empty vector required to satisfy compliance with MINIMALIF-standard rule)
779 #[inline]
780 pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script {
781         Builder::new().push_slice(&funding_pubkey.serialize()[..])
782                 .push_opcode(opcodes::all::OP_CHECKSIG)
783                 .push_opcode(opcodes::all::OP_IFDUP)
784                 .push_opcode(opcodes::all::OP_NOTIF)
785                 .push_int(16)
786                 .push_opcode(opcodes::all::OP_CSV)
787                 .push_opcode(opcodes::all::OP_ENDIF)
788                 .into_script()
789 }
790
791 #[cfg(anchors)]
792 /// Locates the output with an anchor script paying to `funding_pubkey` within `commitment_tx`.
793 pub(crate) fn get_anchor_output<'a>(commitment_tx: &'a Transaction, funding_pubkey: &PublicKey) -> Option<(u32, &'a TxOut)> {
794         let anchor_script = chan_utils::get_anchor_redeemscript(funding_pubkey).to_v0_p2wsh();
795         commitment_tx.output.iter().enumerate()
796                 .find(|(_, txout)| txout.script_pubkey == anchor_script)
797                 .map(|(idx, txout)| (idx as u32, txout))
798 }
799
800 /// Returns the witness required to satisfy and spend an anchor input.
801 pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness {
802         let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key);
803         let mut ret = Witness::new();
804         ret.push_bitcoin_signature(&funding_sig.serialize_der(), EcdsaSighashType::All);
805         ret.push(anchor_redeem_script.as_bytes());
806         ret
807 }
808
809 /// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
810 /// The fields are organized by holder/counterparty.
811 ///
812 /// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters
813 /// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions.
814 #[derive(Clone, Debug, PartialEq, Eq)]
815 pub struct ChannelTransactionParameters {
816         /// Holder public keys
817         pub holder_pubkeys: ChannelPublicKeys,
818         /// The contest delay selected by the holder, which applies to counterparty-broadcast transactions
819         pub holder_selected_contest_delay: u16,
820         /// Whether the holder is the initiator of this channel.
821         /// This is an input to the commitment number obscure factor computation.
822         pub is_outbound_from_holder: bool,
823         /// The late-bound counterparty channel transaction parameters.
824         /// These parameters are populated at the point in the protocol where the counterparty provides them.
825         pub counterparty_parameters: Option<CounterpartyChannelTransactionParameters>,
826         /// The late-bound funding outpoint
827         pub funding_outpoint: Option<chain::transaction::OutPoint>,
828         /// Are anchors (zero fee HTLC transaction variant) used for this channel. Boolean is
829         /// serialization backwards-compatible.
830         pub opt_anchors: Option<()>,
831         /// Are non-zero-fee anchors are enabled (used in conjuction with opt_anchors)
832         /// It is intended merely for backwards compatibility with signers that need it.
833         /// There is no support for this feature in LDK channel negotiation.
834         pub opt_non_zero_fee_anchors: Option<()>,
835 }
836
837 /// Late-bound per-channel counterparty data used to build transactions.
838 #[derive(Clone, Debug, PartialEq, Eq)]
839 pub struct CounterpartyChannelTransactionParameters {
840         /// Counter-party public keys
841         pub pubkeys: ChannelPublicKeys,
842         /// The contest delay selected by the counterparty, which applies to holder-broadcast transactions
843         pub selected_contest_delay: u16,
844 }
845
846 impl ChannelTransactionParameters {
847         /// Whether the late bound parameters are populated.
848         pub fn is_populated(&self) -> bool {
849                 self.counterparty_parameters.is_some() && self.funding_outpoint.is_some()
850         }
851
852         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
853         /// given that the holder is the broadcaster.
854         ///
855         /// self.is_populated() must be true before calling this function.
856         pub fn as_holder_broadcastable(&self) -> DirectedChannelTransactionParameters {
857                 assert!(self.is_populated(), "self.late_parameters must be set before using as_holder_broadcastable");
858                 DirectedChannelTransactionParameters {
859                         inner: self,
860                         holder_is_broadcaster: true
861                 }
862         }
863
864         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
865         /// given that the counterparty is the broadcaster.
866         ///
867         /// self.is_populated() must be true before calling this function.
868         pub fn as_counterparty_broadcastable(&self) -> DirectedChannelTransactionParameters {
869                 assert!(self.is_populated(), "self.late_parameters must be set before using as_counterparty_broadcastable");
870                 DirectedChannelTransactionParameters {
871                         inner: self,
872                         holder_is_broadcaster: false
873                 }
874         }
875 }
876
877 impl_writeable_tlv_based!(CounterpartyChannelTransactionParameters, {
878         (0, pubkeys, required),
879         (2, selected_contest_delay, required),
880 });
881
882 impl_writeable_tlv_based!(ChannelTransactionParameters, {
883         (0, holder_pubkeys, required),
884         (2, holder_selected_contest_delay, required),
885         (4, is_outbound_from_holder, required),
886         (6, counterparty_parameters, option),
887         (8, funding_outpoint, option),
888         (10, opt_anchors, option),
889         (12, opt_non_zero_fee_anchors, option),
890 });
891
892 /// Static channel fields used to build transactions given per-commitment fields, organized by
893 /// broadcaster/countersignatory.
894 ///
895 /// This is derived from the holder/counterparty-organized ChannelTransactionParameters via the
896 /// as_holder_broadcastable and as_counterparty_broadcastable functions.
897 pub struct DirectedChannelTransactionParameters<'a> {
898         /// The holder's channel static parameters
899         inner: &'a ChannelTransactionParameters,
900         /// Whether the holder is the broadcaster
901         holder_is_broadcaster: bool,
902 }
903
904 impl<'a> DirectedChannelTransactionParameters<'a> {
905         /// Get the channel pubkeys for the broadcaster
906         pub fn broadcaster_pubkeys(&self) -> &ChannelPublicKeys {
907                 if self.holder_is_broadcaster {
908                         &self.inner.holder_pubkeys
909                 } else {
910                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
911                 }
912         }
913
914         /// Get the channel pubkeys for the countersignatory
915         pub fn countersignatory_pubkeys(&self) -> &ChannelPublicKeys {
916                 if self.holder_is_broadcaster {
917                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
918                 } else {
919                         &self.inner.holder_pubkeys
920                 }
921         }
922
923         /// Get the contest delay applicable to the transactions.
924         /// Note that the contest delay was selected by the countersignatory.
925         pub fn contest_delay(&self) -> u16 {
926                 let counterparty_parameters = self.inner.counterparty_parameters.as_ref().unwrap();
927                 if self.holder_is_broadcaster { counterparty_parameters.selected_contest_delay } else { self.inner.holder_selected_contest_delay }
928         }
929
930         /// Whether the channel is outbound from the broadcaster.
931         ///
932         /// The boolean representing the side that initiated the channel is
933         /// an input to the commitment number obscure factor computation.
934         pub fn is_outbound(&self) -> bool {
935                 if self.holder_is_broadcaster { self.inner.is_outbound_from_holder } else { !self.inner.is_outbound_from_holder }
936         }
937
938         /// The funding outpoint
939         pub fn funding_outpoint(&self) -> OutPoint {
940                 self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint()
941         }
942
943         /// Whether to use anchors for this channel
944         pub fn opt_anchors(&self) -> bool {
945                 self.inner.opt_anchors.is_some()
946         }
947 }
948
949 /// Information needed to build and sign a holder's commitment transaction.
950 ///
951 /// The transaction is only signed once we are ready to broadcast.
952 #[derive(Clone)]
953 pub struct HolderCommitmentTransaction {
954         inner: CommitmentTransaction,
955         /// Our counterparty's signature for the transaction
956         pub counterparty_sig: Signature,
957         /// All non-dust counterparty HTLC signatures, in the order they appear in the transaction
958         pub counterparty_htlc_sigs: Vec<Signature>,
959         // Which order the signatures should go in when constructing the final commitment tx witness.
960         // The user should be able to reconstruct this themselves, so we don't bother to expose it.
961         holder_sig_first: bool,
962 }
963
964 impl Deref for HolderCommitmentTransaction {
965         type Target = CommitmentTransaction;
966
967         fn deref(&self) -> &Self::Target { &self.inner }
968 }
969
970 impl Eq for HolderCommitmentTransaction {}
971 impl PartialEq for HolderCommitmentTransaction {
972         // We dont care whether we are signed in equality comparison
973         fn eq(&self, o: &Self) -> bool {
974                 self.inner == o.inner
975         }
976 }
977
978 impl_writeable_tlv_based!(HolderCommitmentTransaction, {
979         (0, inner, required),
980         (2, counterparty_sig, required),
981         (4, holder_sig_first, required),
982         (6, counterparty_htlc_sigs, vec_type),
983 });
984
985 impl HolderCommitmentTransaction {
986         #[cfg(test)]
987         pub fn dummy(htlcs: &mut Vec<(HTLCOutputInCommitment, ())>) -> Self {
988                 let secp_ctx = Secp256k1::new();
989                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
990                 let dummy_sig = sign(&secp_ctx, &secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
991
992                 let keys = TxCreationKeys {
993                         per_commitment_point: dummy_key.clone(),
994                         revocation_key: dummy_key.clone(),
995                         broadcaster_htlc_key: dummy_key.clone(),
996                         countersignatory_htlc_key: dummy_key.clone(),
997                         broadcaster_delayed_payment_key: dummy_key.clone(),
998                 };
999                 let channel_pubkeys = ChannelPublicKeys {
1000                         funding_pubkey: dummy_key.clone(),
1001                         revocation_basepoint: dummy_key.clone(),
1002                         payment_point: dummy_key.clone(),
1003                         delayed_payment_basepoint: dummy_key.clone(),
1004                         htlc_basepoint: dummy_key.clone()
1005                 };
1006                 let channel_parameters = ChannelTransactionParameters {
1007                         holder_pubkeys: channel_pubkeys.clone(),
1008                         holder_selected_contest_delay: 0,
1009                         is_outbound_from_holder: false,
1010                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }),
1011                         funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
1012                         opt_anchors: None,
1013                         opt_non_zero_fee_anchors: None,
1014                 };
1015                 let mut counterparty_htlc_sigs = Vec::new();
1016                 for _ in 0..htlcs.len() {
1017                         counterparty_htlc_sigs.push(dummy_sig);
1018                 }
1019                 let inner = CommitmentTransaction::new_with_auxiliary_htlc_data(0, 0, 0, false, dummy_key.clone(), dummy_key.clone(), keys, 0, htlcs, &channel_parameters.as_counterparty_broadcastable());
1020                 htlcs.sort_by_key(|htlc| htlc.0.transaction_output_index);
1021                 HolderCommitmentTransaction {
1022                         inner,
1023                         counterparty_sig: dummy_sig,
1024                         counterparty_htlc_sigs,
1025                         holder_sig_first: false
1026                 }
1027         }
1028
1029         /// Create a new holder transaction with the given counterparty signatures.
1030         /// The funding keys are used to figure out which signature should go first when building the transaction for broadcast.
1031         pub fn new(commitment_tx: CommitmentTransaction, counterparty_sig: Signature, counterparty_htlc_sigs: Vec<Signature>, holder_funding_key: &PublicKey, counterparty_funding_key: &PublicKey) -> Self {
1032                 Self {
1033                         inner: commitment_tx,
1034                         counterparty_sig,
1035                         counterparty_htlc_sigs,
1036                         holder_sig_first: holder_funding_key.serialize()[..] < counterparty_funding_key.serialize()[..],
1037                 }
1038         }
1039
1040         pub(crate) fn add_holder_sig(&self, funding_redeemscript: &Script, holder_sig: Signature) -> Transaction {
1041                 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
1042                 let mut tx = self.inner.built.transaction.clone();
1043                 tx.input[0].witness.push(Vec::new());
1044
1045                 if self.holder_sig_first {
1046                         tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
1047                         tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
1048                 } else {
1049                         tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
1050                         tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
1051                 }
1052
1053                 tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
1054                 tx
1055         }
1056 }
1057
1058 /// A pre-built Bitcoin commitment transaction and its txid.
1059 #[derive(Clone)]
1060 pub struct BuiltCommitmentTransaction {
1061         /// The commitment transaction
1062         pub transaction: Transaction,
1063         /// The txid for the commitment transaction.
1064         ///
1065         /// This is provided as a performance optimization, instead of calling transaction.txid()
1066         /// multiple times.
1067         pub txid: Txid,
1068 }
1069
1070 impl_writeable_tlv_based!(BuiltCommitmentTransaction, {
1071         (0, transaction, required),
1072         (2, txid, required),
1073 });
1074
1075 impl BuiltCommitmentTransaction {
1076         /// Get the SIGHASH_ALL sighash value of the transaction.
1077         ///
1078         /// This can be used to verify a signature.
1079         pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1080                 let sighash = &sighash::SighashCache::new(&self.transaction).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1081                 hash_to_message!(sighash)
1082         }
1083
1084         /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
1085         /// because we are about to broadcast a holder transaction.
1086         pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1087                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1088                 sign(secp_ctx, &sighash, funding_key)
1089         }
1090 }
1091
1092 /// This class tracks the per-transaction information needed to build a closing transaction and will
1093 /// actually build it and sign.
1094 ///
1095 /// This class can be used inside a signer implementation to generate a signature given the relevant
1096 /// secret key.
1097 #[derive(Clone, Hash, PartialEq, Eq)]
1098 pub struct ClosingTransaction {
1099         to_holder_value_sat: u64,
1100         to_counterparty_value_sat: u64,
1101         to_holder_script: Script,
1102         to_counterparty_script: Script,
1103         built: Transaction,
1104 }
1105
1106 impl ClosingTransaction {
1107         /// Construct an object of the class
1108         pub fn new(
1109                 to_holder_value_sat: u64,
1110                 to_counterparty_value_sat: u64,
1111                 to_holder_script: Script,
1112                 to_counterparty_script: Script,
1113                 funding_outpoint: OutPoint,
1114         ) -> Self {
1115                 let built = build_closing_transaction(
1116                         to_holder_value_sat, to_counterparty_value_sat,
1117                         to_holder_script.clone(), to_counterparty_script.clone(),
1118                         funding_outpoint
1119                 );
1120                 ClosingTransaction {
1121                         to_holder_value_sat,
1122                         to_counterparty_value_sat,
1123                         to_holder_script,
1124                         to_counterparty_script,
1125                         built
1126                 }
1127         }
1128
1129         /// Trust our pre-built transaction.
1130         ///
1131         /// Applies a wrapper which allows access to the transaction.
1132         ///
1133         /// This should only be used if you fully trust the builder of this object. It should not
1134         /// be used by an external signer - instead use the verify function.
1135         pub fn trust(&self) -> TrustedClosingTransaction {
1136                 TrustedClosingTransaction { inner: self }
1137         }
1138
1139         /// Verify our pre-built transaction.
1140         ///
1141         /// Applies a wrapper which allows access to the transaction.
1142         ///
1143         /// An external validating signer must call this method before signing
1144         /// or using the built transaction.
1145         pub fn verify(&self, funding_outpoint: OutPoint) -> Result<TrustedClosingTransaction, ()> {
1146                 let built = build_closing_transaction(
1147                         self.to_holder_value_sat, self.to_counterparty_value_sat,
1148                         self.to_holder_script.clone(), self.to_counterparty_script.clone(),
1149                         funding_outpoint
1150                 );
1151                 if self.built != built {
1152                         return Err(())
1153                 }
1154                 Ok(TrustedClosingTransaction { inner: self })
1155         }
1156
1157         /// The value to be sent to the holder, or zero if the output will be omitted
1158         pub fn to_holder_value_sat(&self) -> u64 {
1159                 self.to_holder_value_sat
1160         }
1161
1162         /// The value to be sent to the counterparty, or zero if the output will be omitted
1163         pub fn to_counterparty_value_sat(&self) -> u64 {
1164                 self.to_counterparty_value_sat
1165         }
1166
1167         /// The destination of the holder's output
1168         pub fn to_holder_script(&self) -> &Script {
1169                 &self.to_holder_script
1170         }
1171
1172         /// The destination of the counterparty's output
1173         pub fn to_counterparty_script(&self) -> &Script {
1174                 &self.to_counterparty_script
1175         }
1176 }
1177
1178 /// A wrapper on ClosingTransaction indicating that the built bitcoin
1179 /// transaction is trusted.
1180 ///
1181 /// See trust() and verify() functions on CommitmentTransaction.
1182 ///
1183 /// This structure implements Deref.
1184 pub struct TrustedClosingTransaction<'a> {
1185         inner: &'a ClosingTransaction,
1186 }
1187
1188 impl<'a> Deref for TrustedClosingTransaction<'a> {
1189         type Target = ClosingTransaction;
1190
1191         fn deref(&self) -> &Self::Target { self.inner }
1192 }
1193
1194 impl<'a> TrustedClosingTransaction<'a> {
1195         /// The pre-built Bitcoin commitment transaction
1196         pub fn built_transaction(&self) -> &Transaction {
1197                 &self.inner.built
1198         }
1199
1200         /// Get the SIGHASH_ALL sighash value of the transaction.
1201         ///
1202         /// This can be used to verify a signature.
1203         pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1204                 let sighash = &sighash::SighashCache::new(&self.inner.built).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1205                 hash_to_message!(sighash)
1206         }
1207
1208         /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
1209         /// because we are about to broadcast a holder transaction.
1210         pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1211                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1212                 sign(secp_ctx, &sighash, funding_key)
1213         }
1214 }
1215
1216 /// This class tracks the per-transaction information needed to build a commitment transaction and will
1217 /// actually build it and sign.  It is used for holder transactions that we sign only when needed
1218 /// and for transactions we sign for the counterparty.
1219 ///
1220 /// This class can be used inside a signer implementation to generate a signature given the relevant
1221 /// secret key.
1222 #[derive(Clone)]
1223 pub struct CommitmentTransaction {
1224         commitment_number: u64,
1225         to_broadcaster_value_sat: u64,
1226         to_countersignatory_value_sat: u64,
1227         feerate_per_kw: u32,
1228         htlcs: Vec<HTLCOutputInCommitment>,
1229         // A boolean that is serialization backwards-compatible
1230         opt_anchors: Option<()>,
1231         // Whether non-zero-fee anchors should be used
1232         opt_non_zero_fee_anchors: Option<()>,
1233         // A cache of the parties' pubkeys required to construct the transaction, see doc for trust()
1234         keys: TxCreationKeys,
1235         // For access to the pre-built transaction, see doc for trust()
1236         built: BuiltCommitmentTransaction,
1237 }
1238
1239 impl Eq for CommitmentTransaction {}
1240 impl PartialEq for CommitmentTransaction {
1241         fn eq(&self, o: &Self) -> bool {
1242                 let eq = self.commitment_number == o.commitment_number &&
1243                         self.to_broadcaster_value_sat == o.to_broadcaster_value_sat &&
1244                         self.to_countersignatory_value_sat == o.to_countersignatory_value_sat &&
1245                         self.feerate_per_kw == o.feerate_per_kw &&
1246                         self.htlcs == o.htlcs &&
1247                         self.opt_anchors == o.opt_anchors &&
1248                         self.keys == o.keys;
1249                 if eq {
1250                         debug_assert_eq!(self.built.transaction, o.built.transaction);
1251                         debug_assert_eq!(self.built.txid, o.built.txid);
1252                 }
1253                 eq
1254         }
1255 }
1256
1257 impl_writeable_tlv_based!(CommitmentTransaction, {
1258         (0, commitment_number, required),
1259         (2, to_broadcaster_value_sat, required),
1260         (4, to_countersignatory_value_sat, required),
1261         (6, feerate_per_kw, required),
1262         (8, keys, required),
1263         (10, built, required),
1264         (12, htlcs, vec_type),
1265         (14, opt_anchors, option),
1266         (16, opt_non_zero_fee_anchors, option),
1267 });
1268
1269 impl CommitmentTransaction {
1270         /// Construct an object of the class while assigning transaction output indices to HTLCs.
1271         ///
1272         /// Populates HTLCOutputInCommitment.transaction_output_index in htlcs_with_aux.
1273         ///
1274         /// The generic T allows the caller to match the HTLC output index with auxiliary data.
1275         /// This auxiliary data is not stored in this object.
1276         ///
1277         /// Only include HTLCs that are above the dust limit for the channel.
1278         ///
1279         /// This is not exported to bindings users due to the generic though we likely should expose a version without
1280         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 {
1281                 // Sort outputs and populate output indices while keeping track of the auxiliary data
1282                 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();
1283
1284                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(commitment_number, channel_parameters);
1285                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1286                 let txid = transaction.txid();
1287                 CommitmentTransaction {
1288                         commitment_number,
1289                         to_broadcaster_value_sat,
1290                         to_countersignatory_value_sat,
1291                         feerate_per_kw,
1292                         htlcs,
1293                         opt_anchors: if opt_anchors { Some(()) } else { None },
1294                         keys,
1295                         built: BuiltCommitmentTransaction {
1296                                 transaction,
1297                                 txid
1298                         },
1299                         opt_non_zero_fee_anchors: None,
1300                 }
1301         }
1302
1303         /// Use non-zero fee anchors
1304         ///
1305         /// This is not exported to bindings users due to move, and also not likely to be useful for binding users
1306         pub fn with_non_zero_fee_anchors(mut self) -> Self {
1307                 self.opt_non_zero_fee_anchors = Some(());
1308                 self
1309         }
1310
1311         fn internal_rebuild_transaction(&self, keys: &TxCreationKeys, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<BuiltCommitmentTransaction, ()> {
1312                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(self.commitment_number, channel_parameters);
1313
1314                 let mut htlcs_with_aux = self.htlcs.iter().map(|h| (h.clone(), ())).collect();
1315                 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)?;
1316
1317                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1318                 let txid = transaction.txid();
1319                 let built_transaction = BuiltCommitmentTransaction {
1320                         transaction,
1321                         txid
1322                 };
1323                 Ok(built_transaction)
1324         }
1325
1326         fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec<TxIn>, outputs: Vec<TxOut>) -> Transaction {
1327                 Transaction {
1328                         version: 2,
1329                         lock_time: PackedLockTime(((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32)),
1330                         input: txins,
1331                         output: outputs,
1332                 }
1333         }
1334
1335         // This is used in two cases:
1336         // - initial sorting of outputs / HTLCs in the constructor, in which case T is auxiliary data the
1337         //   caller needs to have sorted together with the HTLCs so it can keep track of the output index
1338         // - building of a bitcoin transaction during a verify() call, in which case T is just ()
1339         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>), ()> {
1340                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1341                 let contest_delay = channel_parameters.contest_delay();
1342
1343                 let mut txouts: Vec<(TxOut, Option<&mut HTLCOutputInCommitment>)> = Vec::new();
1344
1345                 if to_countersignatory_value_sat > 0 {
1346                         let script = if opt_anchors {
1347                             get_to_countersignatory_with_anchors_redeemscript(&countersignatory_pubkeys.payment_point).to_v0_p2wsh()
1348                         } else {
1349                             Payload::p2wpkh(&BitcoinPublicKey::new(countersignatory_pubkeys.payment_point)).unwrap().script_pubkey()
1350                         };
1351                         txouts.push((
1352                                 TxOut {
1353                                         script_pubkey: script.clone(),
1354                                         value: to_countersignatory_value_sat,
1355                                 },
1356                                 None,
1357                         ))
1358                 }
1359
1360                 if to_broadcaster_value_sat > 0 {
1361                         let redeem_script = get_revokeable_redeemscript(
1362                                 &keys.revocation_key,
1363                                 contest_delay,
1364                                 &keys.broadcaster_delayed_payment_key,
1365                         );
1366                         txouts.push((
1367                                 TxOut {
1368                                         script_pubkey: redeem_script.to_v0_p2wsh(),
1369                                         value: to_broadcaster_value_sat,
1370                                 },
1371                                 None,
1372                         ));
1373                 }
1374
1375                 if opt_anchors {
1376                         if to_broadcaster_value_sat > 0 || !htlcs_with_aux.is_empty() {
1377                                 let anchor_script = get_anchor_redeemscript(broadcaster_funding_key);
1378                                 txouts.push((
1379                                         TxOut {
1380                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1381                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1382                                         },
1383                                         None,
1384                                 ));
1385                         }
1386
1387                         if to_countersignatory_value_sat > 0 || !htlcs_with_aux.is_empty() {
1388                                 let anchor_script = get_anchor_redeemscript(countersignatory_funding_key);
1389                                 txouts.push((
1390                                         TxOut {
1391                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1392                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1393                                         },
1394                                         None,
1395                                 ));
1396                         }
1397                 }
1398
1399                 let mut htlcs = Vec::with_capacity(htlcs_with_aux.len());
1400                 for (htlc, _) in htlcs_with_aux {
1401                         let script = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys);
1402                         let txout = TxOut {
1403                                 script_pubkey: script.to_v0_p2wsh(),
1404                                 value: htlc.amount_msat / 1000,
1405                         };
1406                         txouts.push((txout, Some(htlc)));
1407                 }
1408
1409                 // Sort output in BIP-69 order (amount, scriptPubkey).  Tie-breaks based on HTLC
1410                 // CLTV expiration height.
1411                 sort_outputs(&mut txouts, |a, b| {
1412                         if let &Some(ref a_htlcout) = a {
1413                                 if let &Some(ref b_htlcout) = b {
1414                                         a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
1415                                                 // Note that due to hash collisions, we have to have a fallback comparison
1416                                                 // here for fuzzing mode (otherwise at least chanmon_fail_consistency
1417                                                 // may fail)!
1418                                                 .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
1419                                 // For non-HTLC outputs, if they're copying our SPK we don't really care if we
1420                                 // close the channel due to mismatches - they're doing something dumb:
1421                                 } else { cmp::Ordering::Equal }
1422                         } else { cmp::Ordering::Equal }
1423                 });
1424
1425                 let mut outputs = Vec::with_capacity(txouts.len());
1426                 for (idx, out) in txouts.drain(..).enumerate() {
1427                         if let Some(htlc) = out.1 {
1428                                 htlc.transaction_output_index = Some(idx as u32);
1429                                 htlcs.push(htlc.clone());
1430                         }
1431                         outputs.push(out.0);
1432                 }
1433                 Ok((outputs, htlcs))
1434         }
1435
1436         fn internal_build_inputs(commitment_number: u64, channel_parameters: &DirectedChannelTransactionParameters) -> (u64, Vec<TxIn>) {
1437                 let broadcaster_pubkeys = channel_parameters.broadcaster_pubkeys();
1438                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1439                 let commitment_transaction_number_obscure_factor = get_commitment_transaction_number_obscure_factor(
1440                         &broadcaster_pubkeys.payment_point,
1441                         &countersignatory_pubkeys.payment_point,
1442                         channel_parameters.is_outbound(),
1443                 );
1444
1445                 let obscured_commitment_transaction_number =
1446                         commitment_transaction_number_obscure_factor ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
1447
1448                 let txins = {
1449                         let mut ins: Vec<TxIn> = Vec::new();
1450                         ins.push(TxIn {
1451                                 previous_output: channel_parameters.funding_outpoint(),
1452                                 script_sig: Script::new(),
1453                                 sequence: Sequence(((0x80 as u32) << 8 * 3)
1454                                         | ((obscured_commitment_transaction_number >> 3 * 8) as u32)),
1455                                 witness: Witness::new(),
1456                         });
1457                         ins
1458                 };
1459                 (obscured_commitment_transaction_number, txins)
1460         }
1461
1462         /// The backwards-counting commitment number
1463         pub fn commitment_number(&self) -> u64 {
1464                 self.commitment_number
1465         }
1466
1467         /// The value to be sent to the broadcaster
1468         pub fn to_broadcaster_value_sat(&self) -> u64 {
1469                 self.to_broadcaster_value_sat
1470         }
1471
1472         /// The value to be sent to the counterparty
1473         pub fn to_countersignatory_value_sat(&self) -> u64 {
1474                 self.to_countersignatory_value_sat
1475         }
1476
1477         /// The feerate paid per 1000-weight-unit in this commitment transaction.
1478         pub fn feerate_per_kw(&self) -> u32 {
1479                 self.feerate_per_kw
1480         }
1481
1482         /// The non-dust HTLCs (direction, amt, height expiration, hash, transaction output index)
1483         /// which were included in this commitment transaction in output order.
1484         /// The transaction index is always populated.
1485         ///
1486         /// This is not exported to bindings users as we cannot currently convert Vec references to/from C, though we should
1487         /// expose a less effecient version which creates a Vec of references in the future.
1488         pub fn htlcs(&self) -> &Vec<HTLCOutputInCommitment> {
1489                 &self.htlcs
1490         }
1491
1492         /// Trust our pre-built transaction and derived transaction creation public keys.
1493         ///
1494         /// Applies a wrapper which allows access to these fields.
1495         ///
1496         /// This should only be used if you fully trust the builder of this object.  It should not
1497         /// be used by an external signer - instead use the verify function.
1498         pub fn trust(&self) -> TrustedCommitmentTransaction {
1499                 TrustedCommitmentTransaction { inner: self }
1500         }
1501
1502         /// Verify our pre-built transaction and derived transaction creation public keys.
1503         ///
1504         /// Applies a wrapper which allows access to these fields.
1505         ///
1506         /// An external validating signer must call this method before signing
1507         /// or using the built transaction.
1508         pub fn verify<T: secp256k1::Signing + secp256k1::Verification>(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TrustedCommitmentTransaction, ()> {
1509                 // This is the only field of the key cache that we trust
1510                 let per_commitment_point = self.keys.per_commitment_point;
1511                 let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx);
1512                 if keys != self.keys {
1513                         return Err(());
1514                 }
1515                 let tx = self.internal_rebuild_transaction(&keys, channel_parameters, &broadcaster_keys.funding_pubkey, &countersignatory_keys.funding_pubkey)?;
1516                 if self.built.transaction != tx.transaction || self.built.txid != tx.txid {
1517                         return Err(());
1518                 }
1519                 Ok(TrustedCommitmentTransaction { inner: self })
1520         }
1521 }
1522
1523 /// A wrapper on CommitmentTransaction indicating that the derived fields (the built bitcoin
1524 /// transaction and the transaction creation keys) are trusted.
1525 ///
1526 /// See trust() and verify() functions on CommitmentTransaction.
1527 ///
1528 /// This structure implements Deref.
1529 pub struct TrustedCommitmentTransaction<'a> {
1530         inner: &'a CommitmentTransaction,
1531 }
1532
1533 impl<'a> Deref for TrustedCommitmentTransaction<'a> {
1534         type Target = CommitmentTransaction;
1535
1536         fn deref(&self) -> &Self::Target { self.inner }
1537 }
1538
1539 impl<'a> TrustedCommitmentTransaction<'a> {
1540         /// The transaction ID of the built Bitcoin transaction
1541         pub fn txid(&self) -> Txid {
1542                 self.inner.built.txid
1543         }
1544
1545         /// The pre-built Bitcoin commitment transaction
1546         pub fn built_transaction(&self) -> &BuiltCommitmentTransaction {
1547                 &self.inner.built
1548         }
1549
1550         /// The pre-calculated transaction creation public keys.
1551         pub fn keys(&self) -> &TxCreationKeys {
1552                 &self.inner.keys
1553         }
1554
1555         /// Should anchors be used.
1556         pub fn opt_anchors(&self) -> bool {
1557                 self.opt_anchors.is_some()
1558         }
1559
1560         /// Get a signature for each HTLC which was included in the commitment transaction (ie for
1561         /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
1562         ///
1563         /// The returned Vec has one entry for each HTLC, and in the same order.
1564         ///
1565         /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All.
1566         pub fn get_htlc_sigs<T: secp256k1::Signing>(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
1567                 let inner = self.inner;
1568                 let keys = &inner.keys;
1569                 let txid = inner.built.txid;
1570                 let mut ret = Vec::with_capacity(inner.htlcs.len());
1571                 let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key);
1572
1573                 for this_htlc in inner.htlcs.iter() {
1574                         assert!(this_htlc.transaction_output_index.is_some());
1575                         let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), self.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1576
1577                         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);
1578
1579                         let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]);
1580                         ret.push(sign(secp_ctx, &sighash, &holder_htlc_key));
1581                 }
1582                 Ok(ret)
1583         }
1584
1585         /// Gets a signed HTLC transaction given a preimage (for !htlc.offered) and the holder HTLC transaction signature.
1586         pub(crate) fn get_signed_htlc_tx(&self, channel_parameters: &DirectedChannelTransactionParameters, htlc_index: usize, counterparty_signature: &Signature, signature: &Signature, preimage: &Option<PaymentPreimage>) -> Transaction {
1587                 let inner = self.inner;
1588                 let keys = &inner.keys;
1589                 let txid = inner.built.txid;
1590                 let this_htlc = &inner.htlcs[htlc_index];
1591                 assert!(this_htlc.transaction_output_index.is_some());
1592                 // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction.
1593                 if !this_htlc.offered && preimage.is_none() { unreachable!(); }
1594                 // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
1595                 if  this_htlc.offered && preimage.is_some() { unreachable!(); }
1596
1597                 let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), self.opt_non_zero_fee_anchors.is_some(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1598
1599                 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);
1600
1601                 htlc_tx.input[0].witness = chan_utils::build_htlc_input_witness(
1602                         signature, counterparty_signature, preimage, &htlc_redeemscript, self.opt_anchors(),
1603                 );
1604                 htlc_tx
1605         }
1606 }
1607
1608 /// Commitment transaction numbers which appear in the transactions themselves are XOR'd with a
1609 /// shared secret first. This prevents on-chain observers from discovering how many commitment
1610 /// transactions occurred in a channel before it was closed.
1611 ///
1612 /// This function gets the shared secret from relevant channel public keys and can be used to
1613 /// "decrypt" the commitment transaction number given a commitment transaction on-chain.
1614 pub fn get_commitment_transaction_number_obscure_factor(
1615         broadcaster_payment_basepoint: &PublicKey,
1616         countersignatory_payment_basepoint: &PublicKey,
1617         outbound_from_broadcaster: bool,
1618 ) -> u64 {
1619         let mut sha = Sha256::engine();
1620
1621         if outbound_from_broadcaster {
1622                 sha.input(&broadcaster_payment_basepoint.serialize());
1623                 sha.input(&countersignatory_payment_basepoint.serialize());
1624         } else {
1625                 sha.input(&countersignatory_payment_basepoint.serialize());
1626                 sha.input(&broadcaster_payment_basepoint.serialize());
1627         }
1628         let res = Sha256::from_engine(sha).into_inner();
1629
1630         ((res[26] as u64) << 5 * 8)
1631                 | ((res[27] as u64) << 4 * 8)
1632                 | ((res[28] as u64) << 3 * 8)
1633                 | ((res[29] as u64) << 2 * 8)
1634                 | ((res[30] as u64) << 1 * 8)
1635                 | ((res[31] as u64) << 0 * 8)
1636 }
1637
1638 #[cfg(test)]
1639 mod tests {
1640         use super::CounterpartyCommitmentSecrets;
1641         use crate::{hex, chain};
1642         use crate::prelude::*;
1643         use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
1644         use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
1645         use crate::util::test_utils;
1646         use crate::chain::keysinterface::{ChannelSigner, SignerProvider};
1647         use bitcoin::{Network, Txid};
1648         use bitcoin::hashes::Hash;
1649         use crate::ln::PaymentHash;
1650         use bitcoin::hashes::hex::ToHex;
1651         use bitcoin::util::address::Payload;
1652         use bitcoin::PublicKey as BitcoinPublicKey;
1653
1654         #[test]
1655         fn test_anchors() {
1656                 let secp_ctx = Secp256k1::new();
1657
1658                 let seed = [42; 32];
1659                 let network = Network::Testnet;
1660                 let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
1661                 let signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(false, 1_000_000, 0));
1662                 let counterparty_signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(true, 1_000_000, 1));
1663                 let delayed_payment_base = &signer.pubkeys().delayed_payment_basepoint;
1664                 let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
1665                 let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
1666                 let htlc_basepoint = &signer.pubkeys().htlc_basepoint;
1667                 let holder_pubkeys = signer.pubkeys();
1668                 let counterparty_pubkeys = counterparty_signer.pubkeys();
1669                 let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint);
1670                 let mut channel_parameters = ChannelTransactionParameters {
1671                         holder_pubkeys: holder_pubkeys.clone(),
1672                         holder_selected_contest_delay: 0,
1673                         is_outbound_from_holder: false,
1674                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }),
1675                         funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
1676                         opt_anchors: None,
1677                         opt_non_zero_fee_anchors: None,
1678                 };
1679
1680                 let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
1681
1682                 // Generate broadcaster and counterparty outputs
1683                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1684                         0, 1000, 2000,
1685                         false,
1686                         holder_pubkeys.funding_pubkey,
1687                         counterparty_pubkeys.funding_pubkey,
1688                         keys.clone(), 1,
1689                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1690                 );
1691                 assert_eq!(tx.built.transaction.output.len(), 2);
1692                 assert_eq!(tx.built.transaction.output[1].script_pubkey, Payload::p2wpkh(&BitcoinPublicKey::new(counterparty_pubkeys.payment_point)).unwrap().script_pubkey());
1693
1694                 // Generate broadcaster and counterparty outputs as well as two anchors
1695                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1696                         0, 1000, 2000,
1697                         true,
1698                         holder_pubkeys.funding_pubkey,
1699                         counterparty_pubkeys.funding_pubkey,
1700                         keys.clone(), 1,
1701                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1702                 );
1703                 assert_eq!(tx.built.transaction.output.len(), 4);
1704                 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_to_countersignatory_with_anchors_redeemscript(&counterparty_pubkeys.payment_point).to_v0_p2wsh());
1705
1706                 // Generate broadcaster output and anchor
1707                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1708                         0, 3000, 0,
1709                         true,
1710                         holder_pubkeys.funding_pubkey,
1711                         counterparty_pubkeys.funding_pubkey,
1712                         keys.clone(), 1,
1713                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1714                 );
1715                 assert_eq!(tx.built.transaction.output.len(), 2);
1716
1717                 // Generate counterparty output and anchor
1718                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1719                         0, 0, 3000,
1720                         true,
1721                         holder_pubkeys.funding_pubkey,
1722                         counterparty_pubkeys.funding_pubkey,
1723                         keys.clone(), 1,
1724                         &mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
1725                 );
1726                 assert_eq!(tx.built.transaction.output.len(), 2);
1727
1728                 let received_htlc = HTLCOutputInCommitment {
1729                         offered: false,
1730                         amount_msat: 400000,
1731                         cltv_expiry: 100,
1732                         payment_hash: PaymentHash([42; 32]),
1733                         transaction_output_index: None,
1734                 };
1735
1736                 let offered_htlc = HTLCOutputInCommitment {
1737                         offered: true,
1738                         amount_msat: 600000,
1739                         cltv_expiry: 100,
1740                         payment_hash: PaymentHash([43; 32]),
1741                         transaction_output_index: None,
1742                 };
1743
1744                 // Generate broadcaster output and received and offered HTLC outputs,  w/o anchors
1745                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1746                         0, 3000, 0,
1747                         false,
1748                         holder_pubkeys.funding_pubkey,
1749                         counterparty_pubkeys.funding_pubkey,
1750                         keys.clone(), 1,
1751                         &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())],
1752                         &channel_parameters.as_holder_broadcastable()
1753                 );
1754                 assert_eq!(tx.built.transaction.output.len(), 3);
1755                 assert_eq!(tx.built.transaction.output[0].script_pubkey, get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh());
1756                 assert_eq!(tx.built.transaction.output[1].script_pubkey, get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh());
1757                 assert_eq!(get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh().to_hex(),
1758                                    "0020e43a7c068553003fe68fcae424fb7b28ec5ce48cd8b6744b3945631389bad2fb");
1759                 assert_eq!(get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh().to_hex(),
1760                                    "0020215d61bba56b19e9eadb6107f5a85d7f99c40f65992443f69229c290165bc00d");
1761
1762                 // Generate broadcaster output and received and offered HTLC outputs,  with anchors
1763                 channel_parameters.opt_anchors = Some(());
1764                 let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
1765                         0, 3000, 0,
1766                         true,
1767                         holder_pubkeys.funding_pubkey,
1768                         counterparty_pubkeys.funding_pubkey,
1769                         keys.clone(), 1,
1770                         &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())],
1771                         &channel_parameters.as_holder_broadcastable()
1772                 );
1773                 assert_eq!(tx.built.transaction.output.len(), 5);
1774                 assert_eq!(tx.built.transaction.output[2].script_pubkey, get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh());
1775                 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh());
1776                 assert_eq!(get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh().to_hex(),
1777                                    "0020b70d0649c72b38756885c7a30908d912a7898dd5d79457a7280b8e9a20f3f2bc");
1778                 assert_eq!(get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh().to_hex(),
1779                                    "002087a3faeb1950a469c0e2db4a79b093a41b9526e5a6fc6ef5cb949bde3be379c7");
1780         }
1781
1782         #[test]
1783         fn test_per_commitment_storage() {
1784                 // Test vectors from BOLT 3:
1785                 let mut secrets: Vec<[u8; 32]> = Vec::new();
1786                 let mut monitor;
1787
1788                 macro_rules! test_secrets {
1789                         () => {
1790                                 let mut idx = 281474976710655;
1791                                 for secret in secrets.iter() {
1792                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
1793                                         idx -= 1;
1794                                 }
1795                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
1796                                 assert!(monitor.get_secret(idx).is_none());
1797                         };
1798                 }
1799
1800                 {
1801                         // insert_secret correct sequence
1802                         monitor = CounterpartyCommitmentSecrets::new();
1803                         secrets.clear();
1804
1805                         secrets.push([0; 32]);
1806                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1807                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1808                         test_secrets!();
1809
1810                         secrets.push([0; 32]);
1811                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1812                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1813                         test_secrets!();
1814
1815                         secrets.push([0; 32]);
1816                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1817                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1818                         test_secrets!();
1819
1820                         secrets.push([0; 32]);
1821                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1822                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1823                         test_secrets!();
1824
1825                         secrets.push([0; 32]);
1826                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1827                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1828                         test_secrets!();
1829
1830                         secrets.push([0; 32]);
1831                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1832                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1833                         test_secrets!();
1834
1835                         secrets.push([0; 32]);
1836                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1837                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1838                         test_secrets!();
1839
1840                         secrets.push([0; 32]);
1841                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1842                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
1843                         test_secrets!();
1844                 }
1845
1846                 {
1847                         // insert_secret #1 incorrect
1848                         monitor = CounterpartyCommitmentSecrets::new();
1849                         secrets.clear();
1850
1851                         secrets.push([0; 32]);
1852                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1853                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1854                         test_secrets!();
1855
1856                         secrets.push([0; 32]);
1857                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1858                         assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err());
1859                 }
1860
1861                 {
1862                         // insert_secret #2 incorrect (#1 derived from incorrect)
1863                         monitor = CounterpartyCommitmentSecrets::new();
1864                         secrets.clear();
1865
1866                         secrets.push([0; 32]);
1867                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1868                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1869                         test_secrets!();
1870
1871                         secrets.push([0; 32]);
1872                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1873                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1874                         test_secrets!();
1875
1876                         secrets.push([0; 32]);
1877                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1878                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1879                         test_secrets!();
1880
1881                         secrets.push([0; 32]);
1882                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1883                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1884                 }
1885
1886                 {
1887                         // insert_secret #3 incorrect
1888                         monitor = CounterpartyCommitmentSecrets::new();
1889                         secrets.clear();
1890
1891                         secrets.push([0; 32]);
1892                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1893                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1894                         test_secrets!();
1895
1896                         secrets.push([0; 32]);
1897                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1898                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1899                         test_secrets!();
1900
1901                         secrets.push([0; 32]);
1902                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1903                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1904                         test_secrets!();
1905
1906                         secrets.push([0; 32]);
1907                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1908                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
1909                 }
1910
1911                 {
1912                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
1913                         monitor = CounterpartyCommitmentSecrets::new();
1914                         secrets.clear();
1915
1916                         secrets.push([0; 32]);
1917                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
1918                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1919                         test_secrets!();
1920
1921                         secrets.push([0; 32]);
1922                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
1923                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1924                         test_secrets!();
1925
1926                         secrets.push([0; 32]);
1927                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
1928                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1929                         test_secrets!();
1930
1931                         secrets.push([0; 32]);
1932                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
1933                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1934                         test_secrets!();
1935
1936                         secrets.push([0; 32]);
1937                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
1938                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1939                         test_secrets!();
1940
1941                         secrets.push([0; 32]);
1942                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1943                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
1944                         test_secrets!();
1945
1946                         secrets.push([0; 32]);
1947                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
1948                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
1949                         test_secrets!();
1950
1951                         secrets.push([0; 32]);
1952                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
1953                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
1954                 }
1955
1956                 {
1957                         // insert_secret #5 incorrect
1958                         monitor = CounterpartyCommitmentSecrets::new();
1959                         secrets.clear();
1960
1961                         secrets.push([0; 32]);
1962                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1963                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1964                         test_secrets!();
1965
1966                         secrets.push([0; 32]);
1967                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
1968                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
1969                         test_secrets!();
1970
1971                         secrets.push([0; 32]);
1972                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
1973                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
1974                         test_secrets!();
1975
1976                         secrets.push([0; 32]);
1977                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
1978                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
1979                         test_secrets!();
1980
1981                         secrets.push([0; 32]);
1982                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
1983                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
1984                         test_secrets!();
1985
1986                         secrets.push([0; 32]);
1987                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
1988                         assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err());
1989                 }
1990
1991                 {
1992                         // insert_secret #6 incorrect (5 derived from incorrect)
1993                         monitor = CounterpartyCommitmentSecrets::new();
1994                         secrets.clear();
1995
1996                         secrets.push([0; 32]);
1997                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
1998                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
1999                         test_secrets!();
2000
2001                         secrets.push([0; 32]);
2002                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2003                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2004                         test_secrets!();
2005
2006                         secrets.push([0; 32]);
2007                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2008                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2009                         test_secrets!();
2010
2011                         secrets.push([0; 32]);
2012                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2013                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2014                         test_secrets!();
2015
2016                         secrets.push([0; 32]);
2017                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2018                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2019                         test_secrets!();
2020
2021                         secrets.push([0; 32]);
2022                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
2023                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2024                         test_secrets!();
2025
2026                         secrets.push([0; 32]);
2027                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2028                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2029                         test_secrets!();
2030
2031                         secrets.push([0; 32]);
2032                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2033                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2034                 }
2035
2036                 {
2037                         // insert_secret #7 incorrect
2038                         monitor = CounterpartyCommitmentSecrets::new();
2039                         secrets.clear();
2040
2041                         secrets.push([0; 32]);
2042                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2043                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2044                         test_secrets!();
2045
2046                         secrets.push([0; 32]);
2047                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2048                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2049                         test_secrets!();
2050
2051                         secrets.push([0; 32]);
2052                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2053                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2054                         test_secrets!();
2055
2056                         secrets.push([0; 32]);
2057                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2058                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2059                         test_secrets!();
2060
2061                         secrets.push([0; 32]);
2062                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2063                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2064                         test_secrets!();
2065
2066                         secrets.push([0; 32]);
2067                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2068                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2069                         test_secrets!();
2070
2071                         secrets.push([0; 32]);
2072                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
2073                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2074                         test_secrets!();
2075
2076                         secrets.push([0; 32]);
2077                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2078                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2079                 }
2080
2081                 {
2082                         // insert_secret #8 incorrect
2083                         monitor = CounterpartyCommitmentSecrets::new();
2084                         secrets.clear();
2085
2086                         secrets.push([0; 32]);
2087                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2088                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2089                         test_secrets!();
2090
2091                         secrets.push([0; 32]);
2092                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2093                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2094                         test_secrets!();
2095
2096                         secrets.push([0; 32]);
2097                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2098                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2099                         test_secrets!();
2100
2101                         secrets.push([0; 32]);
2102                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2103                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2104                         test_secrets!();
2105
2106                         secrets.push([0; 32]);
2107                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2108                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2109                         test_secrets!();
2110
2111                         secrets.push([0; 32]);
2112                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2113                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2114                         test_secrets!();
2115
2116                         secrets.push([0; 32]);
2117                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2118                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2119                         test_secrets!();
2120
2121                         secrets.push([0; 32]);
2122                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
2123                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2124                 }
2125         }
2126 }