From b06a652e585735b3d37a795b03c0246026baa1e2 Mon Sep 17 00:00:00 2001 From: Wilmer Paulino Date: Mon, 16 Oct 2023 12:21:52 -0700 Subject: [PATCH] Move HTLCDescriptor to sign module Now that `HTLCDescriptor` is no longer specific to anchors, it doesn't make sense for it to live in the `bump_transaction` module anymore. --- lightning/src/chain/channelmonitor.rs | 4 +- lightning/src/chain/onchaintx.rs | 4 +- lightning/src/events/bump_transaction.rs | 160 +--------------------- lightning/src/ln/channel.rs | 3 +- lightning/src/sign/mod.rs | 148 +++++++++++++++++++- lightning/src/util/test_channel_signer.rs | 2 +- 6 files changed, 158 insertions(+), 163 deletions(-) diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs index d855fdd81..37c3383a3 100644 --- a/lightning/src/chain/channelmonitor.rs +++ b/lightning/src/chain/channelmonitor.rs @@ -42,7 +42,7 @@ use crate::chain; use crate::chain::{BestBlock, WatchedOutput}; use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator, LowerBoundedFeeEstimator}; use crate::chain::transaction::{OutPoint, TransactionData}; -use crate::sign::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource}; +use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, WriteableEcdsaChannelSigner, SignerProvider, EntropySource}; use crate::chain::onchaintx::{ClaimEvent, OnchainTxHandler}; use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderFundingOutput, HolderHTLCOutput, PackageSolvingData, PackageTemplate, RevokedOutput, RevokedHTLCOutput}; use crate::chain::Filter; @@ -50,7 +50,7 @@ use crate::util::logger::Logger; use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, MaybeReadable, UpgradableRequired, Writer, Writeable, U48}; use crate::util::byte_utils; use crate::events::{Event, EventHandler}; -use crate::events::bump_transaction::{ChannelDerivationParameters, AnchorDescriptor, HTLCDescriptor, BumpTransactionEvent}; +use crate::events::bump_transaction::{AnchorDescriptor, BumpTransactionEvent}; use crate::prelude::*; use core::{cmp, mem}; diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index 95824f910..e19493540 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -23,15 +23,13 @@ use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature}; use bitcoin::secp256k1; use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight; -use crate::events::bump_transaction::{ChannelDerivationParameters, HTLCDescriptor}; -use crate::sign::{ChannelSigner, EntropySource, SignerProvider}; +use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, WriteableEcdsaChannelSigner}; use crate::ln::msgs::DecodeError; use crate::ln::PaymentPreimage; use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction}; use crate::chain::ClaimId; use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator}; use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER}; -use crate::sign::WriteableEcdsaChannelSigner; use crate::chain::package::{PackageSolvingData, PackageTemplate}; use crate::util::logger::Logger; use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter}; diff --git a/lightning/src/events/bump_transaction.rs b/lightning/src/events/bump_transaction.rs index 5d5161a67..1fd533d2f 100644 --- a/lightning/src/events/bump_transaction.rs +++ b/lightning/src/events/bump_transaction.rs @@ -21,19 +21,21 @@ use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI; use crate::ln::chan_utils; use crate::ln::chan_utils::{ ANCHOR_INPUT_WITNESS_WEIGHT, HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT, - HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT, ChannelTransactionParameters, HTLCOutputInCommitment + HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT, HTLCOutputInCommitment }; -use crate::ln::PaymentPreimage; use crate::prelude::*; -use crate::sign::{EcdsaChannelSigner, SignerProvider, WriteableEcdsaChannelSigner, P2WPKH_WITNESS_WEIGHT}; +use crate::sign::{ + ChannelDerivationParameters, HTLCDescriptor, EcdsaChannelSigner, SignerProvider, + WriteableEcdsaChannelSigner, P2WPKH_WITNESS_WEIGHT +}; use crate::sync::Mutex; use crate::util::logger::Logger; -use bitcoin::{OutPoint, PackedLockTime, PubkeyHash, Sequence, Script, Transaction, Txid, TxIn, TxOut, Witness, WPubkeyHash}; +use bitcoin::{OutPoint, PackedLockTime, PubkeyHash, Sequence, Script, Transaction, TxIn, TxOut, Witness, WPubkeyHash}; use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR; use bitcoin::consensus::Encodable; use bitcoin::secp256k1; -use bitcoin::secp256k1::{PublicKey, Secp256k1}; +use bitcoin::secp256k1::Secp256k1; use bitcoin::secp256k1::ecdsa::Signature; const EMPTY_SCRIPT_SIG_WEIGHT: u64 = 1 /* empty script_sig */ * WITNESS_SCALE_FACTOR as u64; @@ -42,26 +44,6 @@ const BASE_INPUT_SIZE: u64 = 32 /* txid */ + 4 /* vout */ + 4 /* sequence */; const BASE_INPUT_WEIGHT: u64 = BASE_INPUT_SIZE * WITNESS_SCALE_FACTOR as u64; -/// The parameters required to derive a channel signer via [`SignerProvider`]. -#[derive(Clone, Debug, PartialEq, Eq)] -pub struct ChannelDerivationParameters { - /// The value in satoshis of the channel we're attempting to spend the anchor output of. - pub value_satoshis: u64, - /// The unique identifier to re-derive the signer for the associated channel. - pub keys_id: [u8; 32], - /// The necessary channel parameters that need to be provided to the re-derived signer through - /// [`ChannelSigner::provide_channel_parameters`]. - /// - /// [`ChannelSigner::provide_channel_parameters`]: crate::sign::ChannelSigner::provide_channel_parameters - pub transaction_parameters: ChannelTransactionParameters, -} - -impl_writeable_tlv_based!(ChannelDerivationParameters, { - (0, value_satoshis, required), - (2, keys_id, required), - (4, transaction_parameters, required), -}); - /// A descriptor used to sign for a commitment transaction's anchor output. #[derive(Clone, Debug, PartialEq, Eq)] pub struct AnchorDescriptor { @@ -120,133 +102,6 @@ impl AnchorDescriptor { } } -/// A descriptor used to sign for a commitment transaction's HTLC output. -#[derive(Clone, Debug, PartialEq, Eq)] -pub struct HTLCDescriptor { - /// The parameters required to derive the signer for the HTLC input. - pub channel_derivation_parameters: ChannelDerivationParameters, - /// The txid of the commitment transaction in which the HTLC output lives. - pub commitment_txid: Txid, - /// The number of the commitment transaction in which the HTLC output lives. - pub per_commitment_number: u64, - /// The key tweak corresponding to the number of the commitment transaction in which the HTLC - /// output lives. This tweak is applied to all the basepoints for both parties in the channel to - /// arrive at unique keys per commitment. - /// - /// See for more info. - pub per_commitment_point: PublicKey, - /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs - /// originating from a channel supporting anchor outputs, otherwise it is the channel's - /// negotiated feerate at the time the commitment transaction was built. - pub feerate_per_kw: u32, - /// The details of the HTLC as it appears in the commitment transaction. - pub htlc: HTLCOutputInCommitment, - /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be - /// taken. - pub preimage: Option, - /// The counterparty's signature required to spend the HTLC output. - pub counterparty_sig: Signature -} - -impl_writeable_tlv_based!(HTLCDescriptor, { - (0, channel_derivation_parameters, required), - (1, feerate_per_kw, (default_value, 0)), - (2, commitment_txid, required), - (4, per_commitment_number, required), - (6, per_commitment_point, required), - (8, htlc, required), - (10, preimage, option), - (12, counterparty_sig, required), -}); - -impl HTLCDescriptor { - /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint - /// being spent by the HTLC input in the HTLC transaction. - pub fn outpoint(&self) -> OutPoint { - OutPoint { - txid: self.commitment_txid, - vout: self.htlc.transaction_output_index.unwrap(), - } - } - - /// Returns the UTXO to be spent by the HTLC input, which can be obtained via - /// [`Self::unsigned_tx_input`]. - pub fn previous_utxo(&self, secp: &Secp256k1) -> TxOut { - TxOut { - script_pubkey: self.witness_script(secp).to_v0_p2wsh(), - value: self.htlc.amount_msat / 1000, - } - } - - /// Returns the unsigned transaction input spending the HTLC output in the commitment - /// transaction. - pub fn unsigned_tx_input(&self) -> TxIn { - chan_utils::build_htlc_input( - &self.commitment_txid, &self.htlc, &self.channel_derivation_parameters.transaction_parameters.channel_type_features - ) - } - - /// Returns the delayed output created as a result of spending the HTLC output in the commitment - /// transaction. - pub fn tx_output(&self, secp: &Secp256k1) -> TxOut { - let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); - let broadcaster_keys = channel_params.broadcaster_pubkeys(); - let counterparty_keys = channel_params.countersignatory_pubkeys(); - let broadcaster_delayed_key = chan_utils::derive_public_key( - secp, &self.per_commitment_point, &broadcaster_keys.delayed_payment_basepoint - ); - let counterparty_revocation_key = chan_utils::derive_public_revocation_key( - secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint - ); - chan_utils::build_htlc_output( - self.feerate_per_kw, channel_params.contest_delay(), &self.htlc, - channel_params.channel_type_features(), &broadcaster_delayed_key, &counterparty_revocation_key - ) - } - - /// Returns the witness script of the HTLC output in the commitment transaction. - pub fn witness_script(&self, secp: &Secp256k1) -> Script { - let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); - let broadcaster_keys = channel_params.broadcaster_pubkeys(); - let counterparty_keys = channel_params.countersignatory_pubkeys(); - let broadcaster_htlc_key = chan_utils::derive_public_key( - secp, &self.per_commitment_point, &broadcaster_keys.htlc_basepoint - ); - let counterparty_htlc_key = chan_utils::derive_public_key( - secp, &self.per_commitment_point, &counterparty_keys.htlc_basepoint - ); - let counterparty_revocation_key = chan_utils::derive_public_revocation_key( - secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint - ); - chan_utils::get_htlc_redeemscript_with_explicit_keys( - &self.htlc, channel_params.channel_type_features(), &broadcaster_htlc_key, &counterparty_htlc_key, - &counterparty_revocation_key, - ) - } - - /// Returns the fully signed witness required to spend the HTLC output in the commitment - /// transaction. - pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness { - chan_utils::build_htlc_input_witness( - signature, &self.counterparty_sig, &self.preimage, witness_script, - &self.channel_derivation_parameters.transaction_parameters.channel_type_features - ) - } - - /// Derives the channel signer required to sign the HTLC input. - pub fn derive_channel_signer(&self, signer_provider: &SP) -> S - where - SP::Target: SignerProvider - { - let mut signer = signer_provider.derive_channel_signer( - self.channel_derivation_parameters.value_satoshis, - self.channel_derivation_parameters.keys_id, - ); - signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters); - signer - } -} - /// Represents the different types of transactions, originating from LDK, to be bumped. #[derive(Clone, Debug, PartialEq, Eq)] pub enum BumpTransactionEvent { @@ -342,7 +197,6 @@ pub enum BumpTransactionEvent { /// /// [`EcdsaChannelSigner`]: crate::sign::EcdsaChannelSigner /// [`EcdsaChannelSigner::sign_holder_htlc_transaction`]: crate::sign::EcdsaChannelSigner::sign_holder_htlc_transaction - /// [`HTLCDescriptor::tx_input_witness`]: HTLCDescriptor::tx_input_witness HTLCResolution { /// The unique identifier for the claim of the HTLCs in the confirmed commitment /// transaction. diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 7b14573a1..10ce63770 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -8184,8 +8184,7 @@ mod tests { use bitcoin::hashes::hex::FromHex; use bitcoin::hash_types::Txid; use bitcoin::secp256k1::Message; - use crate::events::bump_transaction::{ChannelDerivationParameters, HTLCDescriptor}; - use crate::sign::EcdsaChannelSigner; + use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, EcdsaChannelSigner}; use crate::ln::PaymentPreimage; use crate::ln::channel::{HTLCOutputInCommitment ,TxCreationKeys}; use crate::ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters}; diff --git a/lightning/src/sign/mod.rs b/lightning/src/sign/mod.rs index 6abf4bd25..5912b7b84 100644 --- a/lightning/src/sign/mod.rs +++ b/lightning/src/sign/mod.rs @@ -30,13 +30,12 @@ use bitcoin::secp256k1::{KeyPair, PublicKey, Scalar, Secp256k1, SecretKey, Signi use bitcoin::secp256k1::ecdh::SharedSecret; use bitcoin::secp256k1::ecdsa::{RecoverableSignature, Signature}; use bitcoin::secp256k1::schnorr; -use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness}; +use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness, Txid}; use crate::util::transaction_utils; use crate::util::crypto::{hkdf_extract_expand_twice, sign, sign_with_aux_rand}; use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs}; use crate::chain::transaction::OutPoint; -use crate::events::bump_transaction::HTLCDescriptor; use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI; use crate::ln::{chan_utils, PaymentPreimage}; use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction}; @@ -401,6 +400,151 @@ impl SpendableOutputDescriptor { } } +/// The parameters required to derive a channel signer via [`SignerProvider`]. +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct ChannelDerivationParameters { + /// The value in satoshis of the channel we're attempting to spend the anchor output of. + pub value_satoshis: u64, + /// The unique identifier to re-derive the signer for the associated channel. + pub keys_id: [u8; 32], + /// The necessary channel parameters that need to be provided to the re-derived signer through + /// [`ChannelSigner::provide_channel_parameters`]. + pub transaction_parameters: ChannelTransactionParameters, +} + +impl_writeable_tlv_based!(ChannelDerivationParameters, { + (0, value_satoshis, required), + (2, keys_id, required), + (4, transaction_parameters, required), +}); + +/// A descriptor used to sign for a commitment transaction's HTLC output. +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct HTLCDescriptor { + /// The parameters required to derive the signer for the HTLC input. + pub channel_derivation_parameters: ChannelDerivationParameters, + /// The txid of the commitment transaction in which the HTLC output lives. + pub commitment_txid: Txid, + /// The number of the commitment transaction in which the HTLC output lives. + pub per_commitment_number: u64, + /// The key tweak corresponding to the number of the commitment transaction in which the HTLC + /// output lives. This tweak is applied to all the basepoints for both parties in the channel to + /// arrive at unique keys per commitment. + /// + /// See for more info. + pub per_commitment_point: PublicKey, + /// The feerate to use on the HTLC claiming transaction. This is always `0` for HTLCs + /// originating from a channel supporting anchor outputs, otherwise it is the channel's + /// negotiated feerate at the time the commitment transaction was built. + pub feerate_per_kw: u32, + /// The details of the HTLC as it appears in the commitment transaction. + pub htlc: HTLCOutputInCommitment, + /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be + /// taken. + pub preimage: Option, + /// The counterparty's signature required to spend the HTLC output. + pub counterparty_sig: Signature +} + +impl_writeable_tlv_based!(HTLCDescriptor, { + (0, channel_derivation_parameters, required), + (1, feerate_per_kw, (default_value, 0)), + (2, commitment_txid, required), + (4, per_commitment_number, required), + (6, per_commitment_point, required), + (8, htlc, required), + (10, preimage, option), + (12, counterparty_sig, required), +}); + +impl HTLCDescriptor { + /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint + /// being spent by the HTLC input in the HTLC transaction. + pub fn outpoint(&self) -> bitcoin::OutPoint { + bitcoin::OutPoint { + txid: self.commitment_txid, + vout: self.htlc.transaction_output_index.unwrap(), + } + } + + /// Returns the UTXO to be spent by the HTLC input, which can be obtained via + /// [`Self::unsigned_tx_input`]. + pub fn previous_utxo(&self, secp: &Secp256k1) -> TxOut { + TxOut { + script_pubkey: self.witness_script(secp).to_v0_p2wsh(), + value: self.htlc.amount_msat / 1000, + } + } + + /// Returns the unsigned transaction input spending the HTLC output in the commitment + /// transaction. + pub fn unsigned_tx_input(&self) -> TxIn { + chan_utils::build_htlc_input( + &self.commitment_txid, &self.htlc, &self.channel_derivation_parameters.transaction_parameters.channel_type_features + ) + } + + /// Returns the delayed output created as a result of spending the HTLC output in the commitment + /// transaction. + pub fn tx_output(&self, secp: &Secp256k1) -> TxOut { + let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); + let broadcaster_keys = channel_params.broadcaster_pubkeys(); + let counterparty_keys = channel_params.countersignatory_pubkeys(); + let broadcaster_delayed_key = chan_utils::derive_public_key( + secp, &self.per_commitment_point, &broadcaster_keys.delayed_payment_basepoint + ); + let counterparty_revocation_key = chan_utils::derive_public_revocation_key( + secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint + ); + chan_utils::build_htlc_output( + self.feerate_per_kw, channel_params.contest_delay(), &self.htlc, + channel_params.channel_type_features(), &broadcaster_delayed_key, &counterparty_revocation_key + ) + } + + /// Returns the witness script of the HTLC output in the commitment transaction. + pub fn witness_script(&self, secp: &Secp256k1) -> Script { + let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable(); + let broadcaster_keys = channel_params.broadcaster_pubkeys(); + let counterparty_keys = channel_params.countersignatory_pubkeys(); + let broadcaster_htlc_key = chan_utils::derive_public_key( + secp, &self.per_commitment_point, &broadcaster_keys.htlc_basepoint + ); + let counterparty_htlc_key = chan_utils::derive_public_key( + secp, &self.per_commitment_point, &counterparty_keys.htlc_basepoint + ); + let counterparty_revocation_key = chan_utils::derive_public_revocation_key( + secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint + ); + chan_utils::get_htlc_redeemscript_with_explicit_keys( + &self.htlc, channel_params.channel_type_features(), &broadcaster_htlc_key, &counterparty_htlc_key, + &counterparty_revocation_key, + ) + } + + /// Returns the fully signed witness required to spend the HTLC output in the commitment + /// transaction. + pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness { + chan_utils::build_htlc_input_witness( + signature, &self.counterparty_sig, &self.preimage, witness_script, + &self.channel_derivation_parameters.transaction_parameters.channel_type_features + ) + } + + /// Derives the channel signer required to sign the HTLC input. + pub fn derive_channel_signer(&self, signer_provider: &SP) -> S + where + SP::Target: SignerProvider + { + let mut signer = signer_provider.derive_channel_signer( + self.channel_derivation_parameters.value_satoshis, + self.channel_derivation_parameters.keys_id, + ); + signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters); + signer + } +} + /// A trait to handle Lightning channel key material without concretizing the channel type or /// the signature mechanism. pub trait ChannelSigner { diff --git a/lightning/src/util/test_channel_signer.rs b/lightning/src/util/test_channel_signer.rs index 99240873f..942671cf4 100644 --- a/lightning/src/util/test_channel_signer.rs +++ b/lightning/src/util/test_channel_signer.rs @@ -23,7 +23,7 @@ use bitcoin::util::sighash; use bitcoin::secp256k1; use bitcoin::secp256k1::{SecretKey, PublicKey}; use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature}; -use crate::events::bump_transaction::HTLCDescriptor; +use crate::sign::HTLCDescriptor; use crate::util::ser::{Writeable, Writer}; use crate::io::Error; use crate::ln::features::ChannelTypeFeatures; -- 2.39.5