Skip to content

Chan_utils helpers visibility relaxation #1839

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Nov 30, 2022
Merged

Chan_utils helpers visibility relaxation #1839

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
2e4fab0
Increase visibility of protocol-level consts
ariard Nov 10, 2022
263d76e
Increase visibility of script helper
ariard Nov 10, 2022
605d30e
Remove get_p2wpkh_redeemscript in favor of lib helper
ariard Nov 11, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
48 changes: 29 additions & 19 deletions lightning/src/ln/chan_utils.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ use bitcoin::blockdata::script::{Script,Builder};
use bitcoin::blockdata::opcodes;
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;
Expand All @@ -25,11 +26,11 @@ use crate::ln::msgs::DecodeError;
use crate::util::ser::{Readable, Writeable, Writer};
use crate::util::{byte_utils, transaction_utils};

use bitcoin::hash_types::WPubkeyHash;
use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
use bitcoin::secp256k1::Error as SecpError;
use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
use bitcoin::PublicKey as BitcoinPublicKey;

use crate::io;
use crate::prelude::*;
Expand All @@ -41,13 +42,20 @@ use core::ops::Deref;
use crate::chain;
use crate::util::crypto::sign;

pub(crate) const MAX_HTLCS: u16 = 483;
pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136;
// The weight of `accepted_htlc_script` can vary in function of its CLTV argument value. We define a
// range that encompasses both its non-anchors and anchors variants.
/// 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;

/// 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;
pub(crate) const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
/// 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;

/// Gets the weight for an HTLC-Success transaction.
#[inline]
Expand All @@ -65,18 +73,24 @@ pub fn htlc_timeout_tx_weight(opt_anchors: bool) -> u64 {
if opt_anchors { 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(crate) enum HTLCClaim {
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(crate) fn from_witness(witness: &Witness) -> Option<Self> {
pub fn from_witness(witness: &Witness) -> Option<Self> {
debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT);
if witness.len() < 2 {
return None;
Expand Down Expand Up @@ -700,7 +714,7 @@ pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, conte

/// Gets the witnessScript for the to_remote output when anchors are enabled.
#[inline]
pub(crate) fn get_to_countersignatory_with_anchors_redeemscript(payment_point: &PublicKey) -> Script {
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)
Expand Down Expand Up @@ -1266,7 +1280,7 @@ impl CommitmentTransaction {
let script = if opt_anchors {
get_to_countersignatory_with_anchors_redeemscript(&countersignatory_pubkeys.payment_point).to_v0_p2wsh()
} else {
get_p2wpkh_redeemscript(&countersignatory_pubkeys.payment_point)
Payload::p2wpkh(&BitcoinPublicKey::new(countersignatory_pubkeys.payment_point)).unwrap().script_pubkey()
};
txouts.push((
TxOut {
Expand Down Expand Up @@ -1572,25 +1586,21 @@ pub fn get_commitment_transaction_number_obscure_factor(
| ((res[31] as u64) << 0 * 8)
}

fn get_p2wpkh_redeemscript(key: &PublicKey) -> Script {
Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
.push_slice(&WPubkeyHash::hash(&key.serialize())[..])
.into_script()
}

#[cfg(test)]
mod tests {
use super::CounterpartyCommitmentSecrets;
use crate::{hex, chain};
use crate::prelude::*;
use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, get_p2wpkh_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
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::chain::keysinterface::{KeysInterface, BaseSign};
use bitcoin::{Network, Txid};
use bitcoin::hashes::Hash;
use crate::ln::PaymentHash;
use bitcoin::hashes::hex::ToHex;
use bitcoin::util::address::Payload;
use bitcoin::PublicKey as BitcoinPublicKey;

#[test]
fn test_anchors() {
Expand Down Expand Up @@ -1629,7 +1639,7 @@ mod tests {
&mut htlcs_with_aux, &channel_parameters.as_holder_broadcastable()
);
assert_eq!(tx.built.transaction.output.len(), 2);
assert_eq!(tx.built.transaction.output[1].script_pubkey, get_p2wpkh_redeemscript(&counterparty_pubkeys.payment_point));
assert_eq!(tx.built.transaction.output[1].script_pubkey, Payload::p2wpkh(&BitcoinPublicKey::new(counterparty_pubkeys.payment_point)).unwrap().script_pubkey());

// Generate broadcaster and counterparty outputs as well as two anchors
let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(
Expand Down