X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchan_utils.rs;h=d1489e2716836f928d5bdc04450f3d8722d4fbc9;hb=e0fe325402862978c66603e598cdf7f6fa628606;hp=aa212b2d2d2d4920b3bc1860449c6aa6f0f8d13d;hpb=b65035f5e9fcb2b5953e6c87451b6f7064db537b;p=rust-lightning diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs index aa212b2d..d1489e27 100644 --- a/lightning/src/ln/chan_utils.rs +++ b/lightning/src/ln/chan_utils.rs @@ -1,34 +1,174 @@ +// This file is Copyright its original authors, visible in version control +// history. +// +// This file is licensed under the Apache License, Version 2.0 or the MIT license +// , at your option. +// You may not use this file except in accordance with one or both of these +// licenses. + //! Various utilities for building scripts and deriving keys related to channels. These are -//! largely of interest for those implementing chain::keysinterface::ChannelKeys message signing -//! by hand. +//! largely of interest for those implementing the traits on [`crate::sign`] by hand. use bitcoin::blockdata::script::{Script,Builder}; use bitcoin::blockdata::opcodes; -use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, SigHashType}; -use bitcoin::consensus::encode::{self, Decodable, Encodable}; -use bitcoin::util::bip143; +use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, EcdsaSighashType}; +use bitcoin::util::sighash; +use bitcoin::util::address::Payload; + +use bitcoin::hashes::{Hash, HashEngine}; +use bitcoin::hashes::sha256::Hash as Sha256; +use bitcoin::hashes::ripemd160::Hash as Ripemd160; +use bitcoin::hash_types::{Txid, PubkeyHash, WPubkeyHash}; + +use crate::chain::chaininterface::fee_for_weight; +use crate::chain::package::WEIGHT_REVOKED_OUTPUT; +use crate::sign::EntropySource; +use crate::ln::{PaymentHash, PaymentPreimage}; +use crate::ln::msgs::DecodeError; +use crate::util::ser::{Readable, RequiredWrapper, Writeable, Writer}; +use crate::util::transaction_utils; + +use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar}; +use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message}; +use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness}; +use bitcoin::PublicKey as BitcoinPublicKey; -use bitcoin_hashes::{Hash, HashEngine}; -use bitcoin_hashes::sha256::Hash as Sha256; -use bitcoin_hashes::ripemd160::Hash as Ripemd160; -use bitcoin_hashes::hash160::Hash as Hash160; -use bitcoin_hashes::sha256d::Hash as Sha256dHash; +use crate::io; +use crate::prelude::*; +use core::cmp; +use crate::ln::chan_utils; +use crate::util::transaction_utils::sort_outputs; +use crate::ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI}; +use core::ops::Deref; +use crate::chain; +use crate::ln::features::ChannelTypeFeatures; +use crate::util::crypto::{sign, sign_with_aux_rand}; -use ln::channelmanager::{PaymentHash, PaymentPreimage}; -use ln::msgs::DecodeError; -use util::ser::{Readable, Writeable, Writer, WriterWriteAdaptor}; +/// Maximum number of one-way in-flight HTLC (protocol-level value). +pub const MAX_HTLCS: u16 = 483; +/// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, non-anchor variant. +pub const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133; +/// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, anchor variant. +pub const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136; -use secp256k1::key::{SecretKey,PublicKey}; -use secp256k1::{Secp256k1, Signature}; -use secp256k1; +/// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value. +/// We define a range that encompasses both its non-anchors and anchors variants. +pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136; +/// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value. +/// We define a range that encompasses both its non-anchors and anchors variants. +/// This is the maximum post-anchor value. +pub const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143; -pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703; -pub(super) const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663; +/// The upper bound weight of an anchor input. +pub const ANCHOR_INPUT_WITNESS_WEIGHT: u64 = 116; +/// The upper bound weight of an HTLC timeout input from a commitment transaction with anchor +/// outputs. +pub const HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 288; +/// The upper bound weight of an HTLC success input from a commitment transaction with anchor +/// outputs. +pub const HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 327; + +/// Gets the weight for an HTLC-Success transaction. +#[inline] +pub fn htlc_success_tx_weight(channel_type_features: &ChannelTypeFeatures) -> u64 { + const HTLC_SUCCESS_TX_WEIGHT: u64 = 703; + const HTLC_SUCCESS_ANCHOR_TX_WEIGHT: u64 = 706; + if channel_type_features.supports_anchors_zero_fee_htlc_tx() { HTLC_SUCCESS_ANCHOR_TX_WEIGHT } else { HTLC_SUCCESS_TX_WEIGHT } +} + +/// Gets the weight for an HTLC-Timeout transaction. +#[inline] +pub fn htlc_timeout_tx_weight(channel_type_features: &ChannelTypeFeatures) -> u64 { + const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663; + const HTLC_TIMEOUT_ANCHOR_TX_WEIGHT: u64 = 666; + if channel_type_features.supports_anchors_zero_fee_htlc_tx() { HTLC_TIMEOUT_ANCHOR_TX_WEIGHT } else { HTLC_TIMEOUT_TX_WEIGHT } +} + +/// Describes the type of HTLC claim as determined by analyzing the witness. +#[derive(PartialEq, Eq)] +pub enum HTLCClaim { + /// Claims an offered output on a commitment transaction through the timeout path. + OfferedTimeout, + /// Claims an offered output on a commitment transaction through the success path. + OfferedPreimage, + /// Claims an accepted output on a commitment transaction through the timeout path. + AcceptedTimeout, + /// Claims an accepted output on a commitment transaction through the success path. + AcceptedPreimage, + /// Claims an offered/accepted output on a commitment transaction through the revocation path. + Revocation, +} + +impl HTLCClaim { + /// Check if a given input witness attempts to claim a HTLC. + pub fn from_witness(witness: &Witness) -> Option { + debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT); + if witness.len() < 2 { + return None; + } + let witness_script = witness.last().unwrap(); + let second_to_last = witness.second_to_last().unwrap(); + if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT { + if witness.len() == 3 && second_to_last.len() == 33 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 32 { + // + Some(Self::OfferedPreimage) + } else if witness.len() == 5 && second_to_last.len() == 0 { + // 0 <> + Some(Self::OfferedTimeout) + } else { + None + } + } else if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS { + // It's possible for the weight of `offered_htlc_script` and `accepted_htlc_script` to + // match so we check for both here. + if witness.len() == 3 && second_to_last.len() == 33 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 32 { + // + Some(Self::OfferedPreimage) + } else if witness.len() == 5 && second_to_last.len() == 0 { + // 0 <> + Some(Self::OfferedTimeout) + } else if witness.len() == 3 && second_to_last.len() == 0 { + // <> + Some(Self::AcceptedTimeout) + } else if witness.len() == 5 && second_to_last.len() == 32 { + // 0 + Some(Self::AcceptedPreimage) + } else { + None + } + } else if witness_script.len() > MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT && + witness_script.len() <= MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT { + // Handle remaining range of ACCEPTED_HTLC_SCRIPT_WEIGHT. + if witness.len() == 3 && second_to_last.len() == 33 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 0 { + // <> + Some(Self::AcceptedTimeout) + } else if witness.len() == 5 && second_to_last.len() == 32 { + // 0 + Some(Self::AcceptedPreimage) + } else { + None + } + } else { + None + } + } +} // Various functions for key derivation and transaction creation for use within channels. Primarily // used in Channel and ChannelMonitor. -pub(super) fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] { +/// Build the commitment secret from the seed and the commitment number +pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] { let mut res: [u8; 32] = commitment_seed.clone(); for i in 0..48 { let bitpos = 47 - i; @@ -40,39 +180,208 @@ pub(super) fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [ res } -/// Derives a per-commitment-transaction private key (eg an htlc key or payment key) from the base -/// private key for that type of key and the per_commitment_point (available in TxCreationKeys) -pub fn derive_private_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result { +/// Build a closing transaction +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 { + let txins = { + let mut ins: Vec = Vec::new(); + ins.push(TxIn { + previous_output: funding_outpoint, + script_sig: Script::new(), + sequence: Sequence::MAX, + witness: Witness::new(), + }); + ins + }; + + let mut txouts: Vec<(TxOut, ())> = Vec::new(); + + if to_counterparty_value_sat > 0 { + txouts.push((TxOut { + script_pubkey: to_counterparty_script, + value: to_counterparty_value_sat + }, ())); + } + + if to_holder_value_sat > 0 { + txouts.push((TxOut { + script_pubkey: to_holder_script, + value: to_holder_value_sat + }, ())); + } + + transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey... + + let mut outputs: Vec = Vec::new(); + for out in txouts.drain(..) { + outputs.push(out.0); + } + + Transaction { + version: 2, + lock_time: PackedLockTime::ZERO, + input: txins, + output: outputs, + } +} + +/// Implements the per-commitment secret storage scheme from +/// [BOLT 3](https://github.com/lightning/bolts/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage). +/// +/// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes +/// or so. +#[derive(Clone)] +pub struct CounterpartyCommitmentSecrets { + old_secrets: [([u8; 32], u64); 49], +} + +impl Eq for CounterpartyCommitmentSecrets {} +impl PartialEq for CounterpartyCommitmentSecrets { + fn eq(&self, other: &Self) -> bool { + for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) { + if secret != o_secret || idx != o_idx { + return false + } + } + true + } +} + +impl CounterpartyCommitmentSecrets { + /// Creates a new empty `CounterpartyCommitmentSecrets` structure. + pub fn new() -> Self { + Self { old_secrets: [([0; 32], 1 << 48); 49], } + } + + #[inline] + fn place_secret(idx: u64) -> u8 { + for i in 0..48 { + if idx & (1 << i) == (1 << i) { + return i + } + } + 48 + } + + /// Returns the minimum index of all stored secrets. Note that indexes start + /// at 1 << 48 and get decremented by one for each new secret. + pub fn get_min_seen_secret(&self) -> u64 { + //TODO This can be optimized? + let mut min = 1 << 48; + for &(_, idx) in self.old_secrets.iter() { + if idx < min { + min = idx; + } + } + min + } + + #[inline] + fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] { + let mut res: [u8; 32] = secret; + for i in 0..bits { + let bitpos = bits - 1 - i; + if idx & (1 << bitpos) == (1 << bitpos) { + res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7); + res = Sha256::hash(&res).into_inner(); + } + } + res + } + + /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret + /// was generated in accordance with BOLT 3 and is consistent with previous secrets. + pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> { + let pos = Self::place_secret(idx); + for i in 0..pos { + let (old_secret, old_idx) = self.old_secrets[i as usize]; + if Self::derive_secret(secret, pos, old_idx) != old_secret { + return Err(()); + } + } + if self.get_min_seen_secret() <= idx { + return Ok(()); + } + self.old_secrets[pos as usize] = (secret, idx); + Ok(()) + } + + /// Returns the secret at `idx`. + /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`]. + pub fn get_secret(&self, idx: u64) -> Option<[u8; 32]> { + for i in 0..self.old_secrets.len() { + if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 { + return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx)) + } + } + assert!(idx < self.get_min_seen_secret()); + None + } +} + +impl Writeable for CounterpartyCommitmentSecrets { + fn write(&self, writer: &mut W) -> Result<(), io::Error> { + for &(ref secret, ref idx) in self.old_secrets.iter() { + writer.write_all(secret)?; + writer.write_all(&idx.to_be_bytes())?; + } + write_tlv_fields!(writer, {}); + Ok(()) + } +} +impl Readable for CounterpartyCommitmentSecrets { + fn read(reader: &mut R) -> Result { + let mut old_secrets = [([0; 32], 1 << 48); 49]; + for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() { + *secret = Readable::read(reader)?; + *idx = Readable::read(reader)?; + } + read_tlv_fields!(reader, {}); + Ok(Self { old_secrets }) + } +} + +/// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key) +/// from the base secret and the per_commitment_point. +pub fn derive_private_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> SecretKey { let mut sha = Sha256::engine(); sha.input(&per_commitment_point.serialize()); sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize()); let res = Sha256::from_engine(sha).into_inner(); - let mut key = base_secret.clone(); - key.add_assign(&res)?; - Ok(key) + base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap()) + .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.") } -pub(super) fn derive_public_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result { +/// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key) +/// from the base point and the per_commitment_key. This is the public equivalent of +/// derive_private_key - using only public keys to derive a public key instead of private keys. +pub fn derive_public_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, base_point: &PublicKey) -> PublicKey { let mut sha = Sha256::engine(); sha.input(&per_commitment_point.serialize()); sha.input(&base_point.serialize()); let res = Sha256::from_engine(sha).into_inner(); - let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&res)?); + let hashkey = PublicKey::from_secret_key(&secp_ctx, + &SecretKey::from_slice(&res).expect("Hashes should always be valid keys unless SHA-256 is broken")); base_point.combine(&hashkey) + .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.") } -/// Derives a revocation key from its constituent parts. -/// Note that this is infallible iff we trust that at least one of the two input keys are randomly -/// generated (ie our own). -pub(super) fn derive_private_revocation_key(secp_ctx: &Secp256k1, per_commitment_secret: &SecretKey, revocation_base_secret: &SecretKey) -> Result { - let revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &revocation_base_secret); +/// Derives a per-commitment-transaction revocation key from its constituent parts. +/// +/// Only the cheating participant owns a valid witness to propagate a revoked +/// commitment transaction, thus per_commitment_secret always come from cheater +/// and revocation_base_secret always come from punisher, which is the broadcaster +/// of the transaction spending with this key knowledge. +pub fn derive_private_revocation_key(secp_ctx: &Secp256k1, + per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey) +-> SecretKey { + let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret); let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret); let rev_append_commit_hash_key = { let mut sha = Sha256::engine(); - sha.input(&revocation_base_point.serialize()); + sha.input(&countersignatory_revocation_base_point.serialize()); sha.input(&per_commitment_point.serialize()); Sha256::from_engine(sha).into_inner() @@ -80,23 +389,36 @@ pub(super) fn derive_private_revocation_key(secp_ctx: &Se let commit_append_rev_hash_key = { let mut sha = Sha256::engine(); sha.input(&per_commitment_point.serialize()); - sha.input(&revocation_base_point.serialize()); + sha.input(&countersignatory_revocation_base_point.serialize()); Sha256::from_engine(sha).into_inner() }; - let mut part_a = revocation_base_secret.clone(); - part_a.mul_assign(&rev_append_commit_hash_key)?; - let mut part_b = per_commitment_secret.clone(); - part_b.mul_assign(&commit_append_rev_hash_key)?; - part_a.add_assign(&part_b[..])?; - Ok(part_a) + let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap()) + .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs"); + let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap()) + .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs"); + countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap()) + .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.") } -pub(super) fn derive_public_revocation_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, revocation_base_point: &PublicKey) -> Result { +/// Derives a per-commitment-transaction revocation public key from its constituent parts. This is +/// the public equivalend of derive_private_revocation_key - using only public keys to derive a +/// public key instead of private keys. +/// +/// Only the cheating participant owns a valid witness to propagate a revoked +/// commitment transaction, thus per_commitment_point always come from cheater +/// and revocation_base_point always come from punisher, which is the broadcaster +/// of the transaction spending with this key knowledge. +/// +/// Note that this is infallible iff we trust that at least one of the two input keys are randomly +/// generated (ie our own). +pub fn derive_public_revocation_key(secp_ctx: &Secp256k1, + per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey) +-> PublicKey { let rev_append_commit_hash_key = { let mut sha = Sha256::engine(); - sha.input(&revocation_base_point.serialize()); + sha.input(&countersignatory_revocation_base_point.serialize()); sha.input(&per_commitment_point.serialize()); Sha256::from_engine(sha).into_inner() @@ -104,51 +426,69 @@ pub(super) fn derive_public_revocation_key(secp_ctx: let commit_append_rev_hash_key = { let mut sha = Sha256::engine(); sha.input(&per_commitment_point.serialize()); - sha.input(&revocation_base_point.serialize()); + sha.input(&countersignatory_revocation_base_point.serialize()); Sha256::from_engine(sha).into_inner() }; - let mut part_a = revocation_base_point.clone(); - part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?; - let mut part_b = per_commitment_point.clone(); - part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?; - part_a.combine(&part_b) + let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap()) + .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs"); + let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap()) + .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs"); + countersignatory_contrib.combine(&broadcaster_contrib) + .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.") } /// The set of public keys which are used in the creation of one commitment transaction. /// These are derived from the channel base keys and per-commitment data. -#[derive(PartialEq)] +/// +/// A broadcaster key is provided from potential broadcaster of the computed transaction. +/// A countersignatory key is coming from a protocol participant unable to broadcast the +/// transaction. +/// +/// These keys are assumed to be good, either because the code derived them from +/// channel basepoints via the new function, or they were obtained via +/// CommitmentTransaction.trust().keys() because we trusted the source of the +/// pre-calculated keys. +#[derive(PartialEq, Eq, Clone, Debug)] pub struct TxCreationKeys { - /// The per-commitment public key which was used to derive the other keys. + /// The broadcaster's per-commitment public key which was used to derive the other keys. pub per_commitment_point: PublicKey, - /// The revocation key which is used to allow the owner of the commitment transaction to - /// provide their counterparty the ability to punish them if they broadcast an old state. - pub(crate) revocation_key: PublicKey, - /// A's HTLC Key - pub(crate) a_htlc_key: PublicKey, - /// B's HTLC Key - pub(crate) b_htlc_key: PublicKey, - /// A's Payment Key (which isn't allowed to be spent from for some delay) - pub(crate) a_delayed_payment_key: PublicKey, - /// B's Payment Key - pub(crate) b_payment_key: PublicKey, + /// The revocation key which is used to allow the broadcaster of the commitment + /// transaction to provide their counterparty the ability to punish them if they broadcast + /// an old state. + pub revocation_key: PublicKey, + /// Broadcaster's HTLC Key + pub broadcaster_htlc_key: PublicKey, + /// Countersignatory's HTLC Key + pub countersignatory_htlc_key: PublicKey, + /// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay) + pub broadcaster_delayed_payment_key: PublicKey, } +impl_writeable_tlv_based!(TxCreationKeys, { + (0, per_commitment_point, required), + (2, revocation_key, required), + (4, broadcaster_htlc_key, required), + (6, countersignatory_htlc_key, required), + (8, broadcaster_delayed_payment_key, required), +}); + /// One counterparty's public keys which do not change over the life of a channel. -#[derive(Clone)] +#[derive(Clone, Debug, Hash, PartialEq, Eq)] pub struct ChannelPublicKeys { /// The public key which is used to sign all commitment transactions, as it appears in the /// on-chain channel lock-in 2-of-2 multisig output. pub funding_pubkey: PublicKey, /// The base point which is used (with derive_public_revocation_key) to derive per-commitment - /// revocation keys. The per-commitment revocation private key is then revealed by the owner of - /// a commitment transaction so that their counterparty can claim all available funds if they - /// broadcast an old state. + /// revocation keys. This is combined with the per-commitment-secret generated by the + /// counterparty to create a secret which the counterparty can reveal to revoke previous + /// states. pub revocation_basepoint: PublicKey, - /// The base point which is used (with derive_public_key) to derive a per-commitment payment - /// public key which receives immediately-spendable non-HTLC-encumbered funds. - pub payment_basepoint: PublicKey, + /// The public key on which the non-broadcaster (ie the countersignatory) receives an immediately + /// spendable primary channel balance on the broadcaster's commitment transaction. This key is + /// static across every commitment transaction. + pub payment_point: PublicKey, /// The base point which is used (with derive_public_key) to derive a per-commitment payment /// public key which receives non-HTLC-encumbered funds which are only available for spending /// after some delay (or can be claimed via the revocation path). @@ -158,50 +498,81 @@ pub struct ChannelPublicKeys { pub htlc_basepoint: PublicKey, } -impl_writeable!(ChannelPublicKeys, 33*5, { - funding_pubkey, - revocation_basepoint, - payment_basepoint, - delayed_payment_basepoint, - htlc_basepoint +impl_writeable_tlv_based!(ChannelPublicKeys, { + (0, funding_pubkey, required), + (2, revocation_basepoint, required), + (4, payment_point, required), + (6, delayed_payment_basepoint, required), + (8, htlc_basepoint, required), }); - impl TxCreationKeys { - pub(crate) fn new(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, a_delayed_payment_base: &PublicKey, a_htlc_base: &PublicKey, b_revocation_base: &PublicKey, b_payment_base: &PublicKey, b_htlc_base: &PublicKey) -> Result { - Ok(TxCreationKeys { + /// Create per-state keys from channel base points and the per-commitment point. + /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions. + pub fn derive_new(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, broadcaster_delayed_payment_base: &PublicKey, broadcaster_htlc_base: &PublicKey, countersignatory_revocation_base: &PublicKey, countersignatory_htlc_base: &PublicKey) -> TxCreationKeys { + TxCreationKeys { per_commitment_point: per_commitment_point.clone(), - revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &b_revocation_base)?, - a_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_htlc_base)?, - b_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &b_htlc_base)?, - a_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_delayed_payment_base)?, - b_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &b_payment_base)?, - }) + revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base), + broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base), + countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base), + broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base), + } + } + + /// Generate per-state keys from channel static keys. + /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions. + pub fn from_channel_static_keys(per_commitment_point: &PublicKey, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1) -> TxCreationKeys { + TxCreationKeys::derive_new( + &secp_ctx, + &per_commitment_point, + &broadcaster_keys.delayed_payment_basepoint, + &broadcaster_keys.htlc_basepoint, + &countersignatory_keys.revocation_basepoint, + &countersignatory_keys.htlc_basepoint, + ) } } -/// Gets the "to_local" output redeemscript, ie the script which is time-locked or spendable by -/// the revocation key -pub(super) fn get_revokeable_redeemscript(revocation_key: &PublicKey, to_self_delay: u16, delayed_payment_key: &PublicKey) -> Script { - Builder::new().push_opcode(opcodes::all::OP_IF) +/// The maximum length of a script returned by get_revokeable_redeemscript. +// Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public +// keys of 33 bytes (+ 1 push). +pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2; + +/// A script either spendable by the revocation +/// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain. +/// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions. +pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> Script { + let res = Builder::new().push_opcode(opcodes::all::OP_IF) .push_slice(&revocation_key.serialize()) .push_opcode(opcodes::all::OP_ELSE) - .push_int(to_self_delay as i64) + .push_int(contest_delay as i64) .push_opcode(opcodes::all::OP_CSV) .push_opcode(opcodes::all::OP_DROP) - .push_slice(&delayed_payment_key.serialize()) + .push_slice(&broadcaster_delayed_payment_key.serialize()) .push_opcode(opcodes::all::OP_ENDIF) .push_opcode(opcodes::all::OP_CHECKSIG) - .into_script() + .into_script(); + debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH); + res +} + +/// Returns the script for the counterparty's output on a holder's commitment transaction based on +/// the channel type. +pub fn get_counterparty_payment_script(channel_type_features: &ChannelTypeFeatures, payment_key: &PublicKey) -> Script { + if channel_type_features.supports_anchors_zero_fee_htlc_tx() { + get_to_countersignatory_with_anchors_redeemscript(payment_key).to_v0_p2wsh() + } else { + Script::new_v0_p2wpkh(&WPubkeyHash::hash(&payment_key.serialize())) + } } -#[derive(Clone, PartialEq)] /// Information about an HTLC as it appears in a commitment transaction +#[derive(Clone, Debug, PartialEq, Eq)] pub struct HTLCOutputInCommitment { /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction). /// Note that this is not the same as whether it is ountbound *from us*. To determine that you /// need to compare this value to whether the commitment transaction in question is that of - /// the remote party or our own. + /// the counterparty or our own. pub offered: bool, /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is /// this divided by 1000. @@ -216,18 +587,26 @@ pub struct HTLCOutputInCommitment { pub transaction_output_index: Option, } +impl_writeable_tlv_based!(HTLCOutputInCommitment, { + (0, offered, required), + (2, amount_msat, required), + (4, cltv_expiry, required), + (6, payment_hash, required), + (8, transaction_output_index, option), +}); + #[inline] -pub(super) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script { +pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script { let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner(); if htlc.offered { - Builder::new().push_opcode(opcodes::all::OP_DUP) + let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP) .push_opcode(opcodes::all::OP_HASH160) - .push_slice(&Hash160::hash(&revocation_key.serialize())[..]) + .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..]) .push_opcode(opcodes::all::OP_EQUAL) .push_opcode(opcodes::all::OP_IF) .push_opcode(opcodes::all::OP_CHECKSIG) .push_opcode(opcodes::all::OP_ELSE) - .push_slice(&b_htlc_key.serialize()[..]) + .push_slice(&countersignatory_htlc_key.serialize()[..]) .push_opcode(opcodes::all::OP_SWAP) .push_opcode(opcodes::all::OP_SIZE) .push_int(32) @@ -236,7 +615,7 @@ pub(super) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_opcode(opcodes::all::OP_DROP) .push_int(2) .push_opcode(opcodes::all::OP_SWAP) - .push_slice(&a_htlc_key.serialize()[..]) + .push_slice(&broadcaster_htlc_key.serialize()[..]) .push_int(2) .push_opcode(opcodes::all::OP_CHECKMULTISIG) .push_opcode(opcodes::all::OP_ELSE) @@ -244,18 +623,23 @@ pub(super) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_slice(&payment_hash160) .push_opcode(opcodes::all::OP_EQUALVERIFY) .push_opcode(opcodes::all::OP_CHECKSIG) - .push_opcode(opcodes::all::OP_ENDIF) - .push_opcode(opcodes::all::OP_ENDIF) - .into_script() + .push_opcode(opcodes::all::OP_ENDIF); + if channel_type_features.supports_anchors_zero_fee_htlc_tx() { + bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1) + .push_opcode(opcodes::all::OP_CSV) + .push_opcode(opcodes::all::OP_DROP); + } + bldr.push_opcode(opcodes::all::OP_ENDIF) + .into_script() } else { - Builder::new().push_opcode(opcodes::all::OP_DUP) + let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP) .push_opcode(opcodes::all::OP_HASH160) - .push_slice(&Hash160::hash(&revocation_key.serialize())[..]) + .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..]) .push_opcode(opcodes::all::OP_EQUAL) .push_opcode(opcodes::all::OP_IF) .push_opcode(opcodes::all::OP_CHECKSIG) .push_opcode(opcodes::all::OP_ELSE) - .push_slice(&b_htlc_key.serialize()[..]) + .push_slice(&countersignatory_htlc_key.serialize()[..]) .push_opcode(opcodes::all::OP_SWAP) .push_opcode(opcodes::all::OP_SIZE) .push_int(32) @@ -266,7 +650,7 @@ pub(super) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_opcode(opcodes::all::OP_EQUALVERIFY) .push_int(2) .push_opcode(opcodes::all::OP_SWAP) - .push_slice(&a_htlc_key.serialize()[..]) + .push_slice(&broadcaster_htlc_key.serialize()[..]) .push_int(2) .push_opcode(opcodes::all::OP_CHECKMULTISIG) .push_opcode(opcodes::all::OP_ELSE) @@ -275,214 +659,1721 @@ pub(super) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_opcode(opcodes::all::OP_CLTV) .push_opcode(opcodes::all::OP_DROP) .push_opcode(opcodes::all::OP_CHECKSIG) - .push_opcode(opcodes::all::OP_ENDIF) - .push_opcode(opcodes::all::OP_ENDIF) - .into_script() + .push_opcode(opcodes::all::OP_ENDIF); + if channel_type_features.supports_anchors_zero_fee_htlc_tx() { + bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1) + .push_opcode(opcodes::all::OP_CSV) + .push_opcode(opcodes::all::OP_DROP); + } + bldr.push_opcode(opcodes::all::OP_ENDIF) + .into_script() } } -/// note here that 'a_revocation_key' is generated using b_revocation_basepoint and a's -/// commitment secret. 'htlc' does *not* need to have its previous_output_index filled. +/// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc +/// does not need to have its previous_output_index filled. #[inline] -pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Script { - get_htlc_redeemscript_with_explicit_keys(htlc, &keys.a_htlc_key, &keys.b_htlc_key, &keys.revocation_key) +pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, keys: &TxCreationKeys) -> Script { + get_htlc_redeemscript_with_explicit_keys(htlc, channel_type_features, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key) } /// Gets the redeemscript for a funding output from the two funding public keys. /// Note that the order of funding public keys does not matter. -pub fn make_funding_redeemscript(a: &PublicKey, b: &PublicKey) -> Script { - let our_funding_key = a.serialize(); - let their_funding_key = b.serialize(); +pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &PublicKey) -> Script { + let broadcaster_funding_key = broadcaster.serialize(); + let countersignatory_funding_key = countersignatory.serialize(); + + make_funding_redeemscript_from_slices(&broadcaster_funding_key, &countersignatory_funding_key) +} +pub(crate) fn make_funding_redeemscript_from_slices(broadcaster_funding_key: &[u8], countersignatory_funding_key: &[u8]) -> Script { let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2); - if our_funding_key[..] < their_funding_key[..] { - builder.push_slice(&our_funding_key) - .push_slice(&their_funding_key) + if broadcaster_funding_key[..] < countersignatory_funding_key[..] { + builder.push_slice(broadcaster_funding_key) + .push_slice(countersignatory_funding_key) } else { - builder.push_slice(&their_funding_key) - .push_slice(&our_funding_key) + builder.push_slice(countersignatory_funding_key) + .push_slice(broadcaster_funding_key) }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script() } -/// panics if htlc.transaction_output_index.is_none()! -pub fn build_htlc_transaction(prev_hash: &Sha256dHash, feerate_per_kw: u64, to_self_delay: u16, htlc: &HTLCOutputInCommitment, a_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction { +/// Builds an unsigned HTLC-Success or HTLC-Timeout transaction from the given channel and HTLC +/// parameters. This is used by [`TrustedCommitmentTransaction::get_htlc_sigs`] to fetch the +/// transaction which needs signing, and can be used to construct an HTLC transaction which is +/// broadcastable given a counterparty HTLC signature. +/// +/// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the +/// commitment transaction). +pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction { let mut txins: Vec = Vec::new(); - txins.push(TxIn { - previous_output: OutPoint { - txid: prev_hash.clone(), - vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"), - }, - script_sig: Script::new(), - sequence: 0, - witness: Vec::new(), - }); - - let total_fee = if htlc.offered { - feerate_per_kw * HTLC_TIMEOUT_TX_WEIGHT / 1000 - } else { - feerate_per_kw * HTLC_SUCCESS_TX_WEIGHT / 1000 - }; + txins.push(build_htlc_input(commitment_txid, htlc, channel_type_features)); let mut txouts: Vec = Vec::new(); - txouts.push(TxOut { - script_pubkey: get_revokeable_redeemscript(revocation_key, to_self_delay, a_delayed_payment_key).to_v0_p2wsh(), - value: htlc.amount_msat / 1000 - total_fee //TODO: BOLT 3 does not specify if we should add amount_msat before dividing or if we should divide by 1000 before subtracting (as we do here) - }); + txouts.push(build_htlc_output( + feerate_per_kw, contest_delay, htlc, channel_type_features, + broadcaster_delayed_payment_key, revocation_key + )); Transaction { version: 2, - lock_time: if htlc.offered { htlc.cltv_expiry } else { 0 }, + lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }), input: txins, output: txouts, } } -/// Signs a transaction created by build_htlc_transaction. If the transaction is an -/// HTLC-Success transaction (ie htlc.offered is false), preimage must be set! -pub(crate) fn sign_htlc_transaction(tx: &mut Transaction, their_sig: &Signature, preimage: &Option, htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey, per_commitment_point: &PublicKey, htlc_base_key: &SecretKey, secp_ctx: &Secp256k1) -> Result<(Signature, Script), ()> { - if tx.input.len() != 1 { return Err(()); } - if tx.input[0].witness.len() != 0 { return Err(()); } +pub(crate) fn build_htlc_input(commitment_txid: &Txid, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures) -> TxIn { + TxIn { + previous_output: OutPoint { + txid: commitment_txid.clone(), + vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"), + }, + script_sig: Script::new(), + sequence: Sequence(if channel_type_features.supports_anchors_zero_fee_htlc_tx() { 1 } else { 0 }), + witness: Witness::new(), + } +} - let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&htlc, a_htlc_key, b_htlc_key, revocation_key); +pub(crate) fn build_htlc_output( + feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey +) -> TxOut { + let weight = if htlc.offered { + htlc_timeout_tx_weight(channel_type_features) + } else { + htlc_success_tx_weight(channel_type_features) + }; + let output_value = if channel_type_features.supports_anchors_zero_fee_htlc_tx() && !channel_type_features.supports_anchors_nonzero_fee_htlc_tx() { + htlc.amount_msat / 1000 + } else { + let total_fee = feerate_per_kw as u64 * weight / 1000; + htlc.amount_msat / 1000 - total_fee + }; - let our_htlc_key = derive_private_key(secp_ctx, per_commitment_point, htlc_base_key).map_err(|_| ())?; - let sighash = hash_to_message!(&bip143::SighashComponents::new(&tx).sighash_all(&tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]); - let local_tx = PublicKey::from_secret_key(&secp_ctx, &our_htlc_key) == *a_htlc_key; - let our_sig = secp_ctx.sign(&sighash, &our_htlc_key); + TxOut { + script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(), + value: output_value, + } +} - tx.input[0].witness.push(Vec::new()); // First is the multisig dummy +/// Returns the witness required to satisfy and spend a HTLC input. +pub fn build_htlc_input_witness( + local_sig: &Signature, remote_sig: &Signature, preimage: &Option, + redeem_script: &Script, channel_type_features: &ChannelTypeFeatures, +) -> Witness { + let remote_sighash_type = if channel_type_features.supports_anchors_zero_fee_htlc_tx() { + EcdsaSighashType::SinglePlusAnyoneCanPay + } else { + EcdsaSighashType::All + }; - if local_tx { // b, then a - tx.input[0].witness.push(their_sig.serialize_der().to_vec()); - tx.input[0].witness.push(our_sig.serialize_der().to_vec()); + let mut witness = Witness::new(); + // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element. + witness.push(vec![]); + witness.push_bitcoin_signature(&remote_sig.serialize_der(), remote_sighash_type); + witness.push_bitcoin_signature(&local_sig.serialize_der(), EcdsaSighashType::All); + if let Some(preimage) = preimage { + witness.push(preimage.0.to_vec()); } else { - tx.input[0].witness.push(our_sig.serialize_der().to_vec()); - tx.input[0].witness.push(their_sig.serialize_der().to_vec()); + // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay. + witness.push(vec![]); } - tx.input[0].witness[1].push(SigHashType::All as u8); - tx.input[0].witness[2].push(SigHashType::All as u8); + witness.push(redeem_script.to_bytes()); + witness +} - if htlc.offered { - tx.input[0].witness.push(Vec::new()); - assert!(preimage.is_none()); +/// Pre-anchors channel type features did not use to get serialized in the following six structs: +/// — [`ChannelTransactionParameters`] +/// — [`CommitmentTransaction`] +/// — [`CounterpartyOfferedHTLCOutput`] +/// — [`CounterpartyReceivedHTLCOutput`] +/// — [`HolderHTLCOutput`] +/// — [`HolderFundingOutput`] +/// +/// To ensure a forwards-compatible serialization, we use odd TLV fields. However, if new features +/// are used that could break security, where old signers should be prevented from handling the +/// serialized data, an optional even-field TLV will be used as a stand-in to break compatibility. +/// +/// This method determines whether or not that option needs to be set based on the chanenl type +/// features, and returns it. +/// +/// [`CounterpartyOfferedHTLCOutput`]: crate::chain::package::CounterpartyOfferedHTLCOutput +/// [`CounterpartyReceivedHTLCOutput`]: crate::chain::package::CounterpartyReceivedHTLCOutput +/// [`HolderHTLCOutput`]: crate::chain::package::HolderHTLCOutput +/// [`HolderFundingOutput`]: crate::chain::package::HolderFundingOutput +pub(crate) fn legacy_deserialization_prevention_marker_for_channel_type_features(features: &ChannelTypeFeatures) -> Option<()> { + let mut legacy_version_bit_set = ChannelTypeFeatures::only_static_remote_key(); + legacy_version_bit_set.set_scid_privacy_required(); + legacy_version_bit_set.set_zero_conf_required(); + + if features.is_subset(&legacy_version_bit_set) { + None } else { - tx.input[0].witness.push(preimage.unwrap().0.to_vec()); + Some(()) } +} - tx.input[0].witness.push(htlc_redeemscript.as_bytes().to_vec()); +/// Gets the witnessScript for the to_remote output when anchors are enabled. +#[inline] +pub fn get_to_countersignatory_with_anchors_redeemscript(payment_point: &PublicKey) -> Script { + Builder::new() + .push_slice(&payment_point.serialize()[..]) + .push_opcode(opcodes::all::OP_CHECKSIGVERIFY) + .push_int(1) + .push_opcode(opcodes::all::OP_CSV) + .into_script() +} - Ok((our_sig, htlc_redeemscript)) +/// Gets the witnessScript for an anchor output from the funding public key. +/// The witness in the spending input must be: +/// +/// After 16 blocks of confirmation, an alternative satisfying witness could be: +/// <> +/// (empty vector required to satisfy compliance with MINIMALIF-standard rule) +#[inline] +pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script { + Builder::new().push_slice(&funding_pubkey.serialize()[..]) + .push_opcode(opcodes::all::OP_CHECKSIG) + .push_opcode(opcodes::all::OP_IFDUP) + .push_opcode(opcodes::all::OP_NOTIF) + .push_int(16) + .push_opcode(opcodes::all::OP_CSV) + .push_opcode(opcodes::all::OP_ENDIF) + .into_script() } -#[derive(Clone)] -/// We use this to track local commitment transactions and put off signing them until we are ready -/// to broadcast. Eventually this will require a signer which is possibly external, but for now we -/// just pass in the SecretKeys required. -pub(crate) struct LocalCommitmentTransaction { - tx: Transaction +/// Locates the output with an anchor script paying to `funding_pubkey` within `commitment_tx`. +pub(crate) fn get_anchor_output<'a>(commitment_tx: &'a Transaction, funding_pubkey: &PublicKey) -> Option<(u32, &'a TxOut)> { + let anchor_script = chan_utils::get_anchor_redeemscript(funding_pubkey).to_v0_p2wsh(); + commitment_tx.output.iter().enumerate() + .find(|(_, txout)| txout.script_pubkey == anchor_script) + .map(|(idx, txout)| (idx as u32, txout)) } -impl LocalCommitmentTransaction { - #[cfg(test)] - pub fn dummy() -> Self { - Self { tx: Transaction { - version: 2, - input: Vec::new(), - output: Vec::new(), - lock_time: 0, - } } + +/// Returns the witness required to satisfy and spend an anchor input. +pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness { + let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key); + let mut ret = Witness::new(); + ret.push_bitcoin_signature(&funding_sig.serialize_der(), EcdsaSighashType::All); + ret.push(anchor_redeem_script.as_bytes()); + ret +} + +/// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction). +/// The fields are organized by holder/counterparty. +/// +/// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters +/// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions. +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +pub struct ChannelTransactionParameters { + /// Holder public keys + pub holder_pubkeys: ChannelPublicKeys, + /// The contest delay selected by the holder, which applies to counterparty-broadcast transactions + pub holder_selected_contest_delay: u16, + /// Whether the holder is the initiator of this channel. + /// This is an input to the commitment number obscure factor computation. + pub is_outbound_from_holder: bool, + /// The late-bound counterparty channel transaction parameters. + /// These parameters are populated at the point in the protocol where the counterparty provides them. + pub counterparty_parameters: Option, + /// The late-bound funding outpoint + pub funding_outpoint: Option, + /// This channel's type, as negotiated during channel open. For old objects where this field + /// wasn't serialized, it will default to static_remote_key at deserialization. + pub channel_type_features: ChannelTypeFeatures +} + +/// Late-bound per-channel counterparty data used to build transactions. +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +pub struct CounterpartyChannelTransactionParameters { + /// Counter-party public keys + pub pubkeys: ChannelPublicKeys, + /// The contest delay selected by the counterparty, which applies to holder-broadcast transactions + pub selected_contest_delay: u16, +} + +impl ChannelTransactionParameters { + /// Whether the late bound parameters are populated. + pub fn is_populated(&self) -> bool { + self.counterparty_parameters.is_some() && self.funding_outpoint.is_some() } - pub fn new_missing_local_sig(mut tx: Transaction, their_sig: &Signature, our_funding_key: &PublicKey, their_funding_key: &PublicKey) -> LocalCommitmentTransaction { - if tx.input.len() != 1 { panic!("Tried to store a commitment transaction that had input count != 1!"); } - if tx.input[0].witness.len() != 0 { panic!("Tried to store a signed commitment transaction?"); } + /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters, + /// given that the holder is the broadcaster. + /// + /// self.is_populated() must be true before calling this function. + pub fn as_holder_broadcastable(&self) -> DirectedChannelTransactionParameters { + assert!(self.is_populated(), "self.late_parameters must be set before using as_holder_broadcastable"); + DirectedChannelTransactionParameters { + inner: self, + holder_is_broadcaster: true + } + } + + /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters, + /// given that the counterparty is the broadcaster. + /// + /// self.is_populated() must be true before calling this function. + pub fn as_counterparty_broadcastable(&self) -> DirectedChannelTransactionParameters { + assert!(self.is_populated(), "self.late_parameters must be set before using as_counterparty_broadcastable"); + DirectedChannelTransactionParameters { + inner: self, + holder_is_broadcaster: false + } + } +} + +impl_writeable_tlv_based!(CounterpartyChannelTransactionParameters, { + (0, pubkeys, required), + (2, selected_contest_delay, required), +}); + +impl Writeable for ChannelTransactionParameters { + fn write(&self, writer: &mut W) -> Result<(), io::Error> { + let legacy_deserialization_prevention_marker = legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features); + write_tlv_fields!(writer, { + (0, self.holder_pubkeys, required), + (2, self.holder_selected_contest_delay, required), + (4, self.is_outbound_from_holder, required), + (6, self.counterparty_parameters, option), + (8, self.funding_outpoint, option), + (10, legacy_deserialization_prevention_marker, option), + (11, self.channel_type_features, required), + }); + Ok(()) + } +} + +impl Readable for ChannelTransactionParameters { + fn read(reader: &mut R) -> Result { + let mut holder_pubkeys = RequiredWrapper(None); + let mut holder_selected_contest_delay = RequiredWrapper(None); + let mut is_outbound_from_holder = RequiredWrapper(None); + let mut counterparty_parameters = None; + let mut funding_outpoint = None; + let mut _legacy_deserialization_prevention_marker: Option<()> = None; + let mut channel_type_features = None; + + read_tlv_fields!(reader, { + (0, holder_pubkeys, required), + (2, holder_selected_contest_delay, required), + (4, is_outbound_from_holder, required), + (6, counterparty_parameters, option), + (8, funding_outpoint, option), + (10, _legacy_deserialization_prevention_marker, option), + (11, channel_type_features, option), + }); - tx.input[0].witness.push(Vec::new()); // First is the multisig dummy + let mut additional_features = ChannelTypeFeatures::empty(); + additional_features.set_anchors_nonzero_fee_htlc_tx_required(); + chain::package::verify_channel_type_features(&channel_type_features, Some(&additional_features))?; - if our_funding_key.serialize()[..] < their_funding_key.serialize()[..] { - tx.input[0].witness.push(Vec::new()); - tx.input[0].witness.push(their_sig.serialize_der().to_vec()); - tx.input[0].witness[2].push(SigHashType::All as u8); + Ok(Self { + holder_pubkeys: holder_pubkeys.0.unwrap(), + holder_selected_contest_delay: holder_selected_contest_delay.0.unwrap(), + is_outbound_from_holder: is_outbound_from_holder.0.unwrap(), + counterparty_parameters, + funding_outpoint, + channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key()) + }) + } +} + +/// Static channel fields used to build transactions given per-commitment fields, organized by +/// broadcaster/countersignatory. +/// +/// This is derived from the holder/counterparty-organized ChannelTransactionParameters via the +/// as_holder_broadcastable and as_counterparty_broadcastable functions. +pub struct DirectedChannelTransactionParameters<'a> { + /// The holder's channel static parameters + inner: &'a ChannelTransactionParameters, + /// Whether the holder is the broadcaster + holder_is_broadcaster: bool, +} + +impl<'a> DirectedChannelTransactionParameters<'a> { + /// Get the channel pubkeys for the broadcaster + pub fn broadcaster_pubkeys(&self) -> &'a ChannelPublicKeys { + if self.holder_is_broadcaster { + &self.inner.holder_pubkeys + } else { + &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys + } + } + + /// Get the channel pubkeys for the countersignatory + pub fn countersignatory_pubkeys(&self) -> &'a ChannelPublicKeys { + if self.holder_is_broadcaster { + &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys } else { - tx.input[0].witness.push(their_sig.serialize_der().to_vec()); - tx.input[0].witness[1].push(SigHashType::All as u8); - tx.input[0].witness.push(Vec::new()); + &self.inner.holder_pubkeys } + } - Self { tx } + /// Get the contest delay applicable to the transactions. + /// Note that the contest delay was selected by the countersignatory. + pub fn contest_delay(&self) -> u16 { + let counterparty_parameters = self.inner.counterparty_parameters.as_ref().unwrap(); + if self.holder_is_broadcaster { counterparty_parameters.selected_contest_delay } else { self.inner.holder_selected_contest_delay } } - pub fn txid(&self) -> Sha256dHash { - self.tx.txid() + /// Whether the channel is outbound from the broadcaster. + /// + /// The boolean representing the side that initiated the channel is + /// an input to the commitment number obscure factor computation. + pub fn is_outbound(&self) -> bool { + if self.holder_is_broadcaster { self.inner.is_outbound_from_holder } else { !self.inner.is_outbound_from_holder } } - pub fn has_local_sig(&self) -> bool { - if self.tx.input.len() != 1 { panic!("Commitment transactions must have input count == 1!"); } - if self.tx.input[0].witness.len() == 4 { - assert!(!self.tx.input[0].witness[1].is_empty()); - assert!(!self.tx.input[0].witness[2].is_empty()); - true - } else { - assert_eq!(self.tx.input[0].witness.len(), 3); - assert!(self.tx.input[0].witness[0].is_empty()); - assert!(self.tx.input[0].witness[1].is_empty() || self.tx.input[0].witness[2].is_empty()); - false + /// The funding outpoint + pub fn funding_outpoint(&self) -> OutPoint { + self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint() + } + + /// Whether to use anchors for this channel + pub fn channel_type_features(&self) -> &'a ChannelTypeFeatures { + &self.inner.channel_type_features + } +} + +/// Information needed to build and sign a holder's commitment transaction. +/// +/// The transaction is only signed once we are ready to broadcast. +#[derive(Clone, Debug)] +pub struct HolderCommitmentTransaction { + inner: CommitmentTransaction, + /// Our counterparty's signature for the transaction + pub counterparty_sig: Signature, + /// All non-dust counterparty HTLC signatures, in the order they appear in the transaction + pub counterparty_htlc_sigs: Vec, + // Which order the signatures should go in when constructing the final commitment tx witness. + // The user should be able to reconstruct this themselves, so we don't bother to expose it. + holder_sig_first: bool, +} + +impl Deref for HolderCommitmentTransaction { + type Target = CommitmentTransaction; + + fn deref(&self) -> &Self::Target { &self.inner } +} + +impl Eq for HolderCommitmentTransaction {} +impl PartialEq for HolderCommitmentTransaction { + // We dont care whether we are signed in equality comparison + fn eq(&self, o: &Self) -> bool { + self.inner == o.inner + } +} + +impl_writeable_tlv_based!(HolderCommitmentTransaction, { + (0, inner, required), + (2, counterparty_sig, required), + (4, holder_sig_first, required), + (6, counterparty_htlc_sigs, required_vec), +}); + +impl HolderCommitmentTransaction { + #[cfg(test)] + pub fn dummy(htlcs: &mut Vec<(HTLCOutputInCommitment, ())>) -> Self { + let secp_ctx = Secp256k1::new(); + let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); + let dummy_sig = sign(&secp_ctx, &secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap()); + + let keys = TxCreationKeys { + per_commitment_point: dummy_key.clone(), + revocation_key: dummy_key.clone(), + broadcaster_htlc_key: dummy_key.clone(), + countersignatory_htlc_key: dummy_key.clone(), + broadcaster_delayed_payment_key: dummy_key.clone(), + }; + let channel_pubkeys = ChannelPublicKeys { + funding_pubkey: dummy_key.clone(), + revocation_basepoint: dummy_key.clone(), + payment_point: dummy_key.clone(), + delayed_payment_basepoint: dummy_key.clone(), + htlc_basepoint: dummy_key.clone() + }; + let channel_parameters = ChannelTransactionParameters { + holder_pubkeys: channel_pubkeys.clone(), + holder_selected_contest_delay: 0, + is_outbound_from_holder: false, + counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }), + funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }), + channel_type_features: ChannelTypeFeatures::only_static_remote_key(), + }; + let mut counterparty_htlc_sigs = Vec::new(); + for _ in 0..htlcs.len() { + counterparty_htlc_sigs.push(dummy_sig); + } + let inner = CommitmentTransaction::new_with_auxiliary_htlc_data(0, 0, 0, dummy_key.clone(), dummy_key.clone(), keys, 0, htlcs, &channel_parameters.as_counterparty_broadcastable()); + htlcs.sort_by_key(|htlc| htlc.0.transaction_output_index); + HolderCommitmentTransaction { + inner, + counterparty_sig: dummy_sig, + counterparty_htlc_sigs, + holder_sig_first: false } } - pub fn add_local_sig(&mut self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) { - if self.has_local_sig() { return; } - let sighash = hash_to_message!(&bip143::SighashComponents::new(&self.tx) - .sighash_all(&self.tx.input[0], funding_redeemscript, channel_value_satoshis)[..]); - let our_sig = secp_ctx.sign(&sighash, funding_key); + /// Create a new holder transaction with the given counterparty signatures. + /// The funding keys are used to figure out which signature should go first when building the transaction for broadcast. + pub fn new(commitment_tx: CommitmentTransaction, counterparty_sig: Signature, counterparty_htlc_sigs: Vec, holder_funding_key: &PublicKey, counterparty_funding_key: &PublicKey) -> Self { + Self { + inner: commitment_tx, + counterparty_sig, + counterparty_htlc_sigs, + holder_sig_first: holder_funding_key.serialize()[..] < counterparty_funding_key.serialize()[..], + } + } + + pub(crate) fn add_holder_sig(&self, funding_redeemscript: &Script, holder_sig: Signature) -> Transaction { + // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element. + let mut tx = self.inner.built.transaction.clone(); + tx.input[0].witness.push(Vec::new()); - if self.tx.input[0].witness[1].is_empty() { - self.tx.input[0].witness[1] = our_sig.serialize_der().to_vec(); - self.tx.input[0].witness[1].push(SigHashType::All as u8); + if self.holder_sig_first { + tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All); + tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All); } else { - self.tx.input[0].witness[2] = our_sig.serialize_der().to_vec(); - self.tx.input[0].witness[2].push(SigHashType::All as u8); + tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All); + tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All); + } + + tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec()); + tx + } +} + +/// A pre-built Bitcoin commitment transaction and its txid. +#[derive(Clone, Debug)] +pub struct BuiltCommitmentTransaction { + /// The commitment transaction + pub transaction: Transaction, + /// The txid for the commitment transaction. + /// + /// This is provided as a performance optimization, instead of calling transaction.txid() + /// multiple times. + pub txid: Txid, +} + +impl_writeable_tlv_based!(BuiltCommitmentTransaction, { + (0, transaction, required), + (2, txid, required), +}); + +impl BuiltCommitmentTransaction { + /// Get the SIGHASH_ALL sighash value of the transaction. + /// + /// This can be used to verify a signature. + pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message { + let sighash = &sighash::SighashCache::new(&self.transaction).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..]; + hash_to_message!(sighash) + } + + /// Signs the counterparty's commitment transaction. + pub fn sign_counterparty_commitment(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) -> Signature { + let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis); + sign(secp_ctx, &sighash, funding_key) + } + + /// Signs the holder commitment transaction because we are about to broadcast it. + pub fn sign_holder_commitment( + &self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, + entropy_source: &ES, secp_ctx: &Secp256k1 + ) -> Signature where ES::Target: EntropySource { + let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis); + sign_with_aux_rand(secp_ctx, &sighash, funding_key, entropy_source) + } +} + +/// This class tracks the per-transaction information needed to build a closing transaction and will +/// actually build it and sign. +/// +/// This class can be used inside a signer implementation to generate a signature given the relevant +/// secret key. +#[derive(Clone, Hash, PartialEq, Eq)] +pub struct ClosingTransaction { + to_holder_value_sat: u64, + to_counterparty_value_sat: u64, + to_holder_script: Script, + to_counterparty_script: Script, + built: Transaction, +} + +impl ClosingTransaction { + /// Construct an object of the class + pub fn new( + to_holder_value_sat: u64, + to_counterparty_value_sat: u64, + to_holder_script: Script, + to_counterparty_script: Script, + funding_outpoint: OutPoint, + ) -> Self { + let built = build_closing_transaction( + to_holder_value_sat, to_counterparty_value_sat, + to_holder_script.clone(), to_counterparty_script.clone(), + funding_outpoint + ); + ClosingTransaction { + to_holder_value_sat, + to_counterparty_value_sat, + to_holder_script, + to_counterparty_script, + built } + } + + /// Trust our pre-built transaction. + /// + /// Applies a wrapper which allows access to the transaction. + /// + /// This should only be used if you fully trust the builder of this object. It should not + /// be used by an external signer - instead use the verify function. + pub fn trust(&self) -> TrustedClosingTransaction { + TrustedClosingTransaction { inner: self } + } + + /// Verify our pre-built transaction. + /// + /// Applies a wrapper which allows access to the transaction. + /// + /// An external validating signer must call this method before signing + /// or using the built transaction. + pub fn verify(&self, funding_outpoint: OutPoint) -> Result { + let built = build_closing_transaction( + self.to_holder_value_sat, self.to_counterparty_value_sat, + self.to_holder_script.clone(), self.to_counterparty_script.clone(), + funding_outpoint + ); + if self.built != built { + return Err(()) + } + Ok(TrustedClosingTransaction { inner: self }) + } - self.tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec()); + /// The value to be sent to the holder, or zero if the output will be omitted + pub fn to_holder_value_sat(&self) -> u64 { + self.to_holder_value_sat } - pub fn without_valid_witness(&self) -> &Transaction { &self.tx } - pub fn with_valid_witness(&self) -> &Transaction { - assert!(self.has_local_sig()); - &self.tx + /// The value to be sent to the counterparty, or zero if the output will be omitted + pub fn to_counterparty_value_sat(&self) -> u64 { + self.to_counterparty_value_sat + } + + /// The destination of the holder's output + pub fn to_holder_script(&self) -> &Script { + &self.to_holder_script + } + + /// The destination of the counterparty's output + pub fn to_counterparty_script(&self) -> &Script { + &self.to_counterparty_script } } -impl PartialEq for LocalCommitmentTransaction { - // We dont care whether we are signed in equality comparison + +/// A wrapper on ClosingTransaction indicating that the built bitcoin +/// transaction is trusted. +/// +/// See trust() and verify() functions on CommitmentTransaction. +/// +/// This structure implements Deref. +pub struct TrustedClosingTransaction<'a> { + inner: &'a ClosingTransaction, +} + +impl<'a> Deref for TrustedClosingTransaction<'a> { + type Target = ClosingTransaction; + + fn deref(&self) -> &Self::Target { self.inner } +} + +impl<'a> TrustedClosingTransaction<'a> { + /// The pre-built Bitcoin commitment transaction + pub fn built_transaction(&self) -> &'a Transaction { + &self.inner.built + } + + /// Get the SIGHASH_ALL sighash value of the transaction. + /// + /// This can be used to verify a signature. + pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message { + let sighash = &sighash::SighashCache::new(&self.inner.built).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..]; + hash_to_message!(sighash) + } + + /// Sign a transaction, either because we are counter-signing the counterparty's transaction or + /// because we are about to broadcast a holder transaction. + pub fn sign(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) -> Signature { + let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis); + sign(secp_ctx, &sighash, funding_key) + } +} + +/// This class tracks the per-transaction information needed to build a commitment transaction and will +/// actually build it and sign. It is used for holder transactions that we sign only when needed +/// and for transactions we sign for the counterparty. +/// +/// This class can be used inside a signer implementation to generate a signature given the relevant +/// secret key. +#[derive(Clone, Debug)] +pub struct CommitmentTransaction { + commitment_number: u64, + to_broadcaster_value_sat: u64, + to_countersignatory_value_sat: u64, + to_broadcaster_delay: Option, // Added in 0.0.117 + feerate_per_kw: u32, + htlcs: Vec, + // Note that on upgrades, some features of existing outputs may be missed. + channel_type_features: ChannelTypeFeatures, + // A cache of the parties' pubkeys required to construct the transaction, see doc for trust() + keys: TxCreationKeys, + // For access to the pre-built transaction, see doc for trust() + built: BuiltCommitmentTransaction, +} + +impl Eq for CommitmentTransaction {} +impl PartialEq for CommitmentTransaction { fn eq(&self, o: &Self) -> bool { - self.txid() == o.txid() + let eq = self.commitment_number == o.commitment_number && + self.to_broadcaster_value_sat == o.to_broadcaster_value_sat && + self.to_countersignatory_value_sat == o.to_countersignatory_value_sat && + self.feerate_per_kw == o.feerate_per_kw && + self.htlcs == o.htlcs && + self.channel_type_features == o.channel_type_features && + self.keys == o.keys; + if eq { + debug_assert_eq!(self.built.transaction, o.built.transaction); + debug_assert_eq!(self.built.txid, o.built.txid); + } + eq } } -impl Writeable for LocalCommitmentTransaction { - fn write(&self, writer: &mut W) -> Result<(), ::std::io::Error> { - if let Err(e) = self.tx.consensus_encode(&mut WriterWriteAdaptor(writer)) { - match e { - encode::Error::Io(e) => return Err(e), - _ => panic!("local tx must have been well-formed!"), + +impl Writeable for CommitmentTransaction { + fn write(&self, writer: &mut W) -> Result<(), io::Error> { + let legacy_deserialization_prevention_marker = legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features); + write_tlv_fields!(writer, { + (0, self.commitment_number, required), + (1, self.to_broadcaster_delay, option), + (2, self.to_broadcaster_value_sat, required), + (4, self.to_countersignatory_value_sat, required), + (6, self.feerate_per_kw, required), + (8, self.keys, required), + (10, self.built, required), + (12, self.htlcs, required_vec), + (14, legacy_deserialization_prevention_marker, option), + (15, self.channel_type_features, required), + }); + Ok(()) + } +} + +impl Readable for CommitmentTransaction { + fn read(reader: &mut R) -> Result { + _init_and_read_len_prefixed_tlv_fields!(reader, { + (0, commitment_number, required), + (1, to_broadcaster_delay, option), + (2, to_broadcaster_value_sat, required), + (4, to_countersignatory_value_sat, required), + (6, feerate_per_kw, required), + (8, keys, required), + (10, built, required), + (12, htlcs, required_vec), + (14, _legacy_deserialization_prevention_marker, option), + (15, channel_type_features, option), + }); + + let mut additional_features = ChannelTypeFeatures::empty(); + additional_features.set_anchors_nonzero_fee_htlc_tx_required(); + chain::package::verify_channel_type_features(&channel_type_features, Some(&additional_features))?; + + Ok(Self { + commitment_number: commitment_number.0.unwrap(), + to_broadcaster_value_sat: to_broadcaster_value_sat.0.unwrap(), + to_countersignatory_value_sat: to_countersignatory_value_sat.0.unwrap(), + to_broadcaster_delay, + feerate_per_kw: feerate_per_kw.0.unwrap(), + keys: keys.0.unwrap(), + built: built.0.unwrap(), + htlcs, + channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key()) + }) + } +} + +impl CommitmentTransaction { + /// Construct an object of the class while assigning transaction output indices to HTLCs. + /// + /// Populates HTLCOutputInCommitment.transaction_output_index in htlcs_with_aux. + /// + /// The generic T allows the caller to match the HTLC output index with auxiliary data. + /// This auxiliary data is not stored in this object. + /// + /// Only include HTLCs that are above the dust limit for the channel. + /// + /// This is not exported to bindings users due to the generic though we likely should expose a version without + pub fn new_with_auxiliary_htlc_data(commitment_number: u64, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, 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 { + // Sort outputs and populate output indices while keeping track of the auxiliary data + let (outputs, htlcs) = Self::internal_build_outputs(&keys, to_broadcaster_value_sat, to_countersignatory_value_sat, htlcs_with_aux, channel_parameters, &broadcaster_funding_key, &countersignatory_funding_key).unwrap(); + + let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(commitment_number, channel_parameters); + let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs); + let txid = transaction.txid(); + CommitmentTransaction { + commitment_number, + to_broadcaster_value_sat, + to_countersignatory_value_sat, + to_broadcaster_delay: Some(channel_parameters.contest_delay()), + feerate_per_kw, + htlcs, + channel_type_features: channel_parameters.channel_type_features().clone(), + keys, + built: BuiltCommitmentTransaction { + transaction, + txid + }, + } + } + + /// Use non-zero fee anchors + /// + /// This is not exported to bindings users due to move, and also not likely to be useful for binding users + pub fn with_non_zero_fee_anchors(mut self) -> Self { + self.channel_type_features.set_anchors_nonzero_fee_htlc_tx_required(); + self + } + + fn internal_rebuild_transaction(&self, keys: &TxCreationKeys, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result { + let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(self.commitment_number, channel_parameters); + + let mut htlcs_with_aux = self.htlcs.iter().map(|h| (h.clone(), ())).collect(); + let (outputs, _) = Self::internal_build_outputs(keys, self.to_broadcaster_value_sat, self.to_countersignatory_value_sat, &mut htlcs_with_aux, channel_parameters, broadcaster_funding_key, countersignatory_funding_key)?; + + let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs); + let txid = transaction.txid(); + let built_transaction = BuiltCommitmentTransaction { + transaction, + txid + }; + Ok(built_transaction) + } + + fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec, outputs: Vec) -> Transaction { + Transaction { + version: 2, + lock_time: PackedLockTime(((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32)), + input: txins, + output: outputs, + } + } + + // This is used in two cases: + // - initial sorting of outputs / HTLCs in the constructor, in which case T is auxiliary data the + // caller needs to have sorted together with the HTLCs so it can keep track of the output index + // - building of a bitcoin transaction during a verify() call, in which case T is just () + fn internal_build_outputs(keys: &TxCreationKeys, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<(Vec, Vec), ()> { + let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys(); + let contest_delay = channel_parameters.contest_delay(); + + let mut txouts: Vec<(TxOut, Option<&mut HTLCOutputInCommitment>)> = Vec::new(); + + if to_countersignatory_value_sat > 0 { + let script = if channel_parameters.channel_type_features().supports_anchors_zero_fee_htlc_tx() { + get_to_countersignatory_with_anchors_redeemscript(&countersignatory_pubkeys.payment_point).to_v0_p2wsh() + } else { + Payload::p2wpkh(&BitcoinPublicKey::new(countersignatory_pubkeys.payment_point)).unwrap().script_pubkey() + }; + txouts.push(( + TxOut { + script_pubkey: script.clone(), + value: to_countersignatory_value_sat, + }, + None, + )) + } + + if to_broadcaster_value_sat > 0 { + let redeem_script = get_revokeable_redeemscript( + &keys.revocation_key, + contest_delay, + &keys.broadcaster_delayed_payment_key, + ); + txouts.push(( + TxOut { + script_pubkey: redeem_script.to_v0_p2wsh(), + value: to_broadcaster_value_sat, + }, + None, + )); + } + + if channel_parameters.channel_type_features().supports_anchors_zero_fee_htlc_tx() { + if to_broadcaster_value_sat > 0 || !htlcs_with_aux.is_empty() { + let anchor_script = get_anchor_redeemscript(broadcaster_funding_key); + txouts.push(( + TxOut { + script_pubkey: anchor_script.to_v0_p2wsh(), + value: ANCHOR_OUTPUT_VALUE_SATOSHI, + }, + None, + )); + } + + if to_countersignatory_value_sat > 0 || !htlcs_with_aux.is_empty() { + let anchor_script = get_anchor_redeemscript(countersignatory_funding_key); + txouts.push(( + TxOut { + script_pubkey: anchor_script.to_v0_p2wsh(), + value: ANCHOR_OUTPUT_VALUE_SATOSHI, + }, + None, + )); } } - Ok(()) + + let mut htlcs = Vec::with_capacity(htlcs_with_aux.len()); + for (htlc, _) in htlcs_with_aux { + let script = chan_utils::get_htlc_redeemscript(&htlc, &channel_parameters.channel_type_features(), &keys); + let txout = TxOut { + script_pubkey: script.to_v0_p2wsh(), + value: htlc.amount_msat / 1000, + }; + txouts.push((txout, Some(htlc))); + } + + // Sort output in BIP-69 order (amount, scriptPubkey). Tie-breaks based on HTLC + // CLTV expiration height. + sort_outputs(&mut txouts, |a, b| { + if let &Some(ref a_htlcout) = a { + if let &Some(ref b_htlcout) = b { + a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry) + // Note that due to hash collisions, we have to have a fallback comparison + // here for fuzzing mode (otherwise at least chanmon_fail_consistency + // may fail)! + .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0)) + // For non-HTLC outputs, if they're copying our SPK we don't really care if we + // close the channel due to mismatches - they're doing something dumb: + } else { cmp::Ordering::Equal } + } else { cmp::Ordering::Equal } + }); + + let mut outputs = Vec::with_capacity(txouts.len()); + for (idx, out) in txouts.drain(..).enumerate() { + if let Some(htlc) = out.1 { + htlc.transaction_output_index = Some(idx as u32); + htlcs.push(htlc.clone()); + } + outputs.push(out.0); + } + Ok((outputs, htlcs)) } + + fn internal_build_inputs(commitment_number: u64, channel_parameters: &DirectedChannelTransactionParameters) -> (u64, Vec) { + let broadcaster_pubkeys = channel_parameters.broadcaster_pubkeys(); + let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys(); + let commitment_transaction_number_obscure_factor = get_commitment_transaction_number_obscure_factor( + &broadcaster_pubkeys.payment_point, + &countersignatory_pubkeys.payment_point, + channel_parameters.is_outbound(), + ); + + let obscured_commitment_transaction_number = + commitment_transaction_number_obscure_factor ^ (INITIAL_COMMITMENT_NUMBER - commitment_number); + + let txins = { + let mut ins: Vec = Vec::new(); + ins.push(TxIn { + previous_output: channel_parameters.funding_outpoint(), + script_sig: Script::new(), + sequence: Sequence(((0x80 as u32) << 8 * 3) + | ((obscured_commitment_transaction_number >> 3 * 8) as u32)), + witness: Witness::new(), + }); + ins + }; + (obscured_commitment_transaction_number, txins) + } + + /// The backwards-counting commitment number + pub fn commitment_number(&self) -> u64 { + self.commitment_number + } + + /// The value to be sent to the broadcaster + pub fn to_broadcaster_value_sat(&self) -> u64 { + self.to_broadcaster_value_sat + } + + /// The value to be sent to the counterparty + pub fn to_countersignatory_value_sat(&self) -> u64 { + self.to_countersignatory_value_sat + } + + /// The feerate paid per 1000-weight-unit in this commitment transaction. + pub fn feerate_per_kw(&self) -> u32 { + self.feerate_per_kw + } + + /// The non-dust HTLCs (direction, amt, height expiration, hash, transaction output index) + /// which were included in this commitment transaction in output order. + /// The transaction index is always populated. + /// + /// This is not exported to bindings users as we cannot currently convert Vec references to/from C, though we should + /// expose a less effecient version which creates a Vec of references in the future. + pub fn htlcs(&self) -> &Vec { + &self.htlcs + } + + /// Trust our pre-built transaction and derived transaction creation public keys. + /// + /// Applies a wrapper which allows access to these fields. + /// + /// This should only be used if you fully trust the builder of this object. It should not + /// be used by an external signer - instead use the verify function. + pub fn trust(&self) -> TrustedCommitmentTransaction { + TrustedCommitmentTransaction { inner: self } + } + + /// Verify our pre-built transaction and derived transaction creation public keys. + /// + /// Applies a wrapper which allows access to these fields. + /// + /// An external validating signer must call this method before signing + /// or using the built transaction. + pub fn verify(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1) -> Result { + // This is the only field of the key cache that we trust + let per_commitment_point = self.keys.per_commitment_point; + let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx); + if keys != self.keys { + return Err(()); + } + let tx = self.internal_rebuild_transaction(&keys, channel_parameters, &broadcaster_keys.funding_pubkey, &countersignatory_keys.funding_pubkey)?; + if self.built.transaction != tx.transaction || self.built.txid != tx.txid { + return Err(()); + } + Ok(TrustedCommitmentTransaction { inner: self }) + } +} + +/// A wrapper on CommitmentTransaction indicating that the derived fields (the built bitcoin +/// transaction and the transaction creation keys) are trusted. +/// +/// See trust() and verify() functions on CommitmentTransaction. +/// +/// This structure implements Deref. +pub struct TrustedCommitmentTransaction<'a> { + inner: &'a CommitmentTransaction, +} + +impl<'a> Deref for TrustedCommitmentTransaction<'a> { + type Target = CommitmentTransaction; + + fn deref(&self) -> &Self::Target { self.inner } } -impl Readable for LocalCommitmentTransaction { - fn read(reader: &mut R) -> Result { - let tx = match Transaction::consensus_decode(reader.by_ref()) { - Ok(tx) => tx, - Err(e) => match e { - encode::Error::Io(ioe) => return Err(DecodeError::Io(ioe)), - _ => return Err(DecodeError::InvalidValue), + +impl<'a> TrustedCommitmentTransaction<'a> { + /// The transaction ID of the built Bitcoin transaction + pub fn txid(&self) -> Txid { + self.inner.built.txid + } + + /// The pre-built Bitcoin commitment transaction + pub fn built_transaction(&self) -> &'a BuiltCommitmentTransaction { + &self.inner.built + } + + /// The pre-calculated transaction creation public keys. + pub fn keys(&self) -> &'a TxCreationKeys { + &self.inner.keys + } + + /// Should anchors be used. + pub fn channel_type_features(&self) -> &'a ChannelTypeFeatures { + &self.inner.channel_type_features + } + + /// Get a signature for each HTLC which was included in the commitment transaction (ie for + /// which HTLCOutputInCommitment::transaction_output_index.is_some()). + /// + /// The returned Vec has one entry for each HTLC, and in the same order. + /// + /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All. + pub fn get_htlc_sigs( + &self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, + entropy_source: &ES, secp_ctx: &Secp256k1, + ) -> Result, ()> where ES::Target: EntropySource { + let inner = self.inner; + let keys = &inner.keys; + let txid = inner.built.txid; + let mut ret = Vec::with_capacity(inner.htlcs.len()); + let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key); + + for this_htlc in inner.htlcs.iter() { + assert!(this_htlc.transaction_output_index.is_some()); + let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &self.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); + + let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &self.channel_type_features, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key); + + let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]); + ret.push(sign_with_aux_rand(secp_ctx, &sighash, &holder_htlc_key, entropy_source)); + } + Ok(ret) + } + + /// Gets a signed HTLC transaction given a preimage (for !htlc.offered) and the holder HTLC transaction signature. + pub(crate) fn get_signed_htlc_tx(&self, channel_parameters: &DirectedChannelTransactionParameters, htlc_index: usize, counterparty_signature: &Signature, signature: &Signature, preimage: &Option) -> Transaction { + let inner = self.inner; + let keys = &inner.keys; + let txid = inner.built.txid; + let this_htlc = &inner.htlcs[htlc_index]; + assert!(this_htlc.transaction_output_index.is_some()); + // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction. + if !this_htlc.offered && preimage.is_none() { unreachable!(); } + // Further, we should never be provided the preimage for an HTLC-Timeout transaction. + if this_htlc.offered && preimage.is_some() { unreachable!(); } + + let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &self.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); + + let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &self.channel_type_features, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key); + + htlc_tx.input[0].witness = chan_utils::build_htlc_input_witness( + signature, counterparty_signature, preimage, &htlc_redeemscript, &self.channel_type_features, + ); + htlc_tx + } + + /// Returns the index of the revokeable output, i.e. the `to_local` output sending funds to + /// the broadcaster, in the built transaction, if any exists. + /// + /// There are two cases where this may return `None`: + /// - The balance of the revokeable output is below the dust limit (only found on commitments + /// early in the channel's lifetime, i.e. before the channel reserve is met). + /// - This commitment was created before LDK 0.0.117. In this case, the + /// commitment transaction previously didn't contain enough information to locate the + /// revokeable output. + pub fn revokeable_output_index(&self) -> Option { + let revokeable_redeemscript = get_revokeable_redeemscript( + &self.keys.revocation_key, + self.to_broadcaster_delay?, + &self.keys.broadcaster_delayed_payment_key, + ); + let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh(); + let outputs = &self.inner.built.transaction.output; + outputs.iter().enumerate() + .find(|(_, out)| out.script_pubkey == revokeable_p2wsh) + .map(|(idx, _)| idx) + } + + /// Helper method to build an unsigned justice transaction spending the revokeable + /// `to_local` output to a destination script. Fee estimation accounts for the expected + /// revocation witness data that will be added when signed. + /// + /// This method will error if the given fee rate results in a fee greater than the value + /// of the output being spent, or if there exists no revokeable `to_local` output on this + /// commitment transaction. See [`Self::revokeable_output_index`] for more details. + /// + /// The built transaction will allow fee bumping with RBF, and this method takes + /// `feerate_per_kw` as an input such that multiple copies of a justice transaction at different + /// fee rates may be built. + pub fn build_to_local_justice_tx(&self, feerate_per_kw: u64, destination_script: Script) + -> Result { + let output_idx = self.revokeable_output_index().ok_or(())?; + let input = vec![TxIn { + previous_output: OutPoint { + txid: self.trust().txid(), + vout: output_idx as u32, }, + script_sig: Script::new(), + sequence: Sequence::ENABLE_RBF_NO_LOCKTIME, + witness: Witness::new(), + }]; + let value = self.inner.built.transaction.output[output_idx].value; + let output = vec![TxOut { + script_pubkey: destination_script, + value, + }]; + let mut justice_tx = Transaction { + version: 2, + lock_time: PackedLockTime::ZERO, + input, + output, + }; + let weight = justice_tx.weight() as u64 + WEIGHT_REVOKED_OUTPUT; + let fee = fee_for_weight(feerate_per_kw as u32, weight); + justice_tx.output[0].value = value.checked_sub(fee).ok_or(())?; + Ok(justice_tx) + } + +} + +/// Commitment transaction numbers which appear in the transactions themselves are XOR'd with a +/// shared secret first. This prevents on-chain observers from discovering how many commitment +/// transactions occurred in a channel before it was closed. +/// +/// This function gets the shared secret from relevant channel public keys and can be used to +/// "decrypt" the commitment transaction number given a commitment transaction on-chain. +pub fn get_commitment_transaction_number_obscure_factor( + broadcaster_payment_basepoint: &PublicKey, + countersignatory_payment_basepoint: &PublicKey, + outbound_from_broadcaster: bool, +) -> u64 { + let mut sha = Sha256::engine(); + + if outbound_from_broadcaster { + sha.input(&broadcaster_payment_basepoint.serialize()); + sha.input(&countersignatory_payment_basepoint.serialize()); + } else { + sha.input(&countersignatory_payment_basepoint.serialize()); + sha.input(&broadcaster_payment_basepoint.serialize()); + } + let res = Sha256::from_engine(sha).into_inner(); + + ((res[26] as u64) << 5 * 8) + | ((res[27] as u64) << 4 * 8) + | ((res[28] as u64) << 3 * 8) + | ((res[29] as u64) << 2 * 8) + | ((res[30] as u64) << 1 * 8) + | ((res[31] as u64) << 0 * 8) +} + +#[cfg(test)] +mod tests { + use super::{CounterpartyCommitmentSecrets, ChannelPublicKeys}; + use crate::{hex, chain}; + use crate::prelude::*; + use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment}; + use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1}; + use crate::util::test_utils; + use crate::sign::{ChannelSigner, SignerProvider}; + use bitcoin::{Network, Txid, Script}; + use bitcoin::hashes::Hash; + use crate::ln::PaymentHash; + use bitcoin::hashes::hex::ToHex; + use bitcoin::util::address::Payload; + use bitcoin::PublicKey as BitcoinPublicKey; + use crate::ln::features::ChannelTypeFeatures; + + struct TestCommitmentTxBuilder { + commitment_number: u64, + holder_funding_pubkey: PublicKey, + counterparty_funding_pubkey: PublicKey, + keys: TxCreationKeys, + feerate_per_kw: u32, + htlcs_with_aux: Vec<(HTLCOutputInCommitment, ())>, + channel_parameters: ChannelTransactionParameters, + counterparty_pubkeys: ChannelPublicKeys, + } + + impl TestCommitmentTxBuilder { + fn new() -> Self { + let secp_ctx = Secp256k1::new(); + let seed = [42; 32]; + let network = Network::Testnet; + let keys_provider = test_utils::TestKeysInterface::new(&seed, network); + let signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(false, 1_000_000, 0)); + let counterparty_signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(true, 1_000_000, 1)); + let delayed_payment_base = &signer.pubkeys().delayed_payment_basepoint; + let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap(); + let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret); + let htlc_basepoint = &signer.pubkeys().htlc_basepoint; + let holder_pubkeys = signer.pubkeys(); + let counterparty_pubkeys = counterparty_signer.pubkeys().clone(); + let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint); + let channel_parameters = ChannelTransactionParameters { + holder_pubkeys: holder_pubkeys.clone(), + holder_selected_contest_delay: 0, + is_outbound_from_holder: false, + counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }), + funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }), + channel_type_features: ChannelTypeFeatures::only_static_remote_key(), + }; + let htlcs_with_aux = Vec::new(); + + Self { + commitment_number: 0, + holder_funding_pubkey: holder_pubkeys.funding_pubkey, + counterparty_funding_pubkey: counterparty_pubkeys.funding_pubkey, + keys, + feerate_per_kw: 1, + htlcs_with_aux, + channel_parameters, + counterparty_pubkeys, + } + } + + fn build(&mut self, to_broadcaster_sats: u64, to_countersignatory_sats: u64) -> CommitmentTransaction { + CommitmentTransaction::new_with_auxiliary_htlc_data( + self.commitment_number, to_broadcaster_sats, to_countersignatory_sats, + self.holder_funding_pubkey.clone(), + self.counterparty_funding_pubkey.clone(), + self.keys.clone(), self.feerate_per_kw, + &mut self.htlcs_with_aux, &self.channel_parameters.as_holder_broadcastable() + ) + } + } + + #[test] + fn test_anchors() { + let mut builder = TestCommitmentTxBuilder::new(); + + // Generate broadcaster and counterparty outputs + let tx = builder.build(1000, 2000); + assert_eq!(tx.built.transaction.output.len(), 2); + assert_eq!(tx.built.transaction.output[1].script_pubkey, Payload::p2wpkh(&BitcoinPublicKey::new(builder.counterparty_pubkeys.payment_point)).unwrap().script_pubkey()); + + // Generate broadcaster and counterparty outputs as well as two anchors + builder.channel_parameters.channel_type_features = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(); + let tx = builder.build(1000, 2000); + assert_eq!(tx.built.transaction.output.len(), 4); + assert_eq!(tx.built.transaction.output[3].script_pubkey, get_to_countersignatory_with_anchors_redeemscript(&builder.counterparty_pubkeys.payment_point).to_v0_p2wsh()); + + // Generate broadcaster output and anchor + let tx = builder.build(3000, 0); + assert_eq!(tx.built.transaction.output.len(), 2); + + // Generate counterparty output and anchor + let tx = builder.build(0, 3000); + assert_eq!(tx.built.transaction.output.len(), 2); + + let received_htlc = HTLCOutputInCommitment { + offered: false, + amount_msat: 400000, + cltv_expiry: 100, + payment_hash: PaymentHash([42; 32]), + transaction_output_index: None, + }; + + let offered_htlc = HTLCOutputInCommitment { + offered: true, + amount_msat: 600000, + cltv_expiry: 100, + payment_hash: PaymentHash([43; 32]), + transaction_output_index: None, }; - if tx.input.len() != 1 { - // Ensure tx didn't hit the 0-input ambiguity case. - return Err(DecodeError::InvalidValue); + // Generate broadcaster output and received and offered HTLC outputs, w/o anchors + builder.channel_parameters.channel_type_features = ChannelTypeFeatures::only_static_remote_key(); + builder.htlcs_with_aux = vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())]; + let tx = builder.build(3000, 0); + let keys = &builder.keys.clone(); + assert_eq!(tx.built.transaction.output.len(), 3); + assert_eq!(tx.built.transaction.output[0].script_pubkey, get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh()); + assert_eq!(tx.built.transaction.output[1].script_pubkey, get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh()); + assert_eq!(get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh().to_hex(), + "0020e43a7c068553003fe68fcae424fb7b28ec5ce48cd8b6744b3945631389bad2fb"); + assert_eq!(get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh().to_hex(), + "0020215d61bba56b19e9eadb6107f5a85d7f99c40f65992443f69229c290165bc00d"); + + // Generate broadcaster output and received and offered HTLC outputs, with anchors + builder.channel_parameters.channel_type_features = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(); + builder.htlcs_with_aux = vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())]; + let tx = builder.build(3000, 0); + assert_eq!(tx.built.transaction.output.len(), 5); + assert_eq!(tx.built.transaction.output[2].script_pubkey, get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh()); + assert_eq!(tx.built.transaction.output[3].script_pubkey, get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh()); + assert_eq!(get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh().to_hex(), + "0020b70d0649c72b38756885c7a30908d912a7898dd5d79457a7280b8e9a20f3f2bc"); + assert_eq!(get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh().to_hex(), + "002087a3faeb1950a469c0e2db4a79b093a41b9526e5a6fc6ef5cb949bde3be379c7"); + } + + #[test] + fn test_finding_revokeable_output_index() { + let mut builder = TestCommitmentTxBuilder::new(); + + // Revokeable output present + let tx = builder.build(1000, 2000); + assert_eq!(tx.built.transaction.output.len(), 2); + assert_eq!(tx.trust().revokeable_output_index(), Some(0)); + + // Revokeable output present (but to_broadcaster_delay missing) + let tx = CommitmentTransaction { to_broadcaster_delay: None, ..tx }; + assert_eq!(tx.built.transaction.output.len(), 2); + assert_eq!(tx.trust().revokeable_output_index(), None); + + // Revokeable output not present (our balance is dust) + let tx = builder.build(0, 2000); + assert_eq!(tx.built.transaction.output.len(), 1); + assert_eq!(tx.trust().revokeable_output_index(), None); + } + + #[test] + fn test_building_to_local_justice_tx() { + let mut builder = TestCommitmentTxBuilder::new(); + + // Revokeable output not present (our balance is dust) + let tx = builder.build(0, 2000); + assert_eq!(tx.built.transaction.output.len(), 1); + assert!(tx.trust().build_to_local_justice_tx(253, Script::new()).is_err()); + + // Revokeable output present + let tx = builder.build(1000, 2000); + assert_eq!(tx.built.transaction.output.len(), 2); + + // Too high feerate + assert!(tx.trust().build_to_local_justice_tx(100_000, Script::new()).is_err()); + + // Generate a random public key for destination script + let secret_key = SecretKey::from_slice( + &hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100") + .unwrap()[..]).unwrap(); + let pubkey_hash = BitcoinPublicKey::new( + PublicKey::from_secret_key(&Secp256k1::new(), &secret_key)).wpubkey_hash().unwrap(); + let destination_script = Script::new_v0_p2wpkh(&pubkey_hash); + + let justice_tx = tx.trust().build_to_local_justice_tx(253, destination_script.clone()).unwrap(); + assert_eq!(justice_tx.input.len(), 1); + assert_eq!(justice_tx.input[0].previous_output.txid, tx.built.transaction.txid()); + assert_eq!(justice_tx.input[0].previous_output.vout, tx.trust().revokeable_output_index().unwrap() as u32); + assert!(justice_tx.input[0].sequence.is_rbf()); + + assert_eq!(justice_tx.output.len(), 1); + assert!(justice_tx.output[0].value < 1000); + assert_eq!(justice_tx.output[0].script_pubkey, destination_script); + } + + #[test] + fn test_per_commitment_storage() { + // Test vectors from BOLT 3: + let mut secrets: Vec<[u8; 32]> = Vec::new(); + let mut monitor; + + macro_rules! test_secrets { + () => { + let mut idx = 281474976710655; + for secret in secrets.iter() { + assert_eq!(monitor.get_secret(idx).unwrap(), *secret); + idx -= 1; + } + assert_eq!(monitor.get_min_seen_secret(), idx + 1); + assert!(monitor.get_secret(idx).is_none()); + }; + } + + { + // insert_secret correct sequence + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap()); + monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap()); + monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap()); + monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + } + + { + // insert_secret #1 incorrect + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #2 incorrect (#1 derived from incorrect) + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #3 incorrect + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #4 incorrect (1,2,3 derived from incorrect) + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap()); + monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap()); + monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap()); + assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #5 incorrect + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap()); + assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #6 incorrect (5 derived from incorrect) + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap()); + monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap()); + monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap()); + assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #7 incorrect + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap()); + monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap()); + monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap()); + assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err()); + } + + { + // insert_secret #8 incorrect + monitor = CounterpartyCommitmentSecrets::new(); + secrets.clear(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()); + monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap()); + monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap()); + monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap()); + monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap()); + monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap()); + monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap()); + monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap(); + test_secrets!(); + + secrets.push([0; 32]); + secrets.last_mut().unwrap()[0..32].clone_from_slice(&hex::decode("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap()); + assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err()); } - Ok(Self { tx }) } }