Merge pull request #1839 from ariard/2022-11-increase-visibility-helpers

Chan_utils helpers visibility relaxation

Author: TheBlueMatt

lightning/src/ln/chan_utils.rs

@@ -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;
@@ -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::*;
@@ -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]
@@ -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;
@@ -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)
@@ -1284,7 +1298,7 @@ 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 {
@@ -1590,25 +1604,21 @@ 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() {
@@ -1648,7 +1658,7 @@ 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(