Dry-up witnessScript in sign_remote_htlc_transaction

[rust-lightning] / lightning / src / ln / chan_utils.rs

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index d833eca91c5fcf185f347bf88f788cb6b1dff20e..e619716a3cc8cfea5cd4c4688da6f5dad5056729 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -11,8 +11,7 @@ use bitcoin::util::bip143;
 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::hash_types::Txid;
+use bitcoin::hash_types::{Txid, PubkeyHash};
 
 use ln::channelmanager::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
@@ -174,7 +173,7 @@ impl Readable for CounterpartyCommitmentSecrets {
 
 /// 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<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
+pub(crate) fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
        let mut sha = Sha256::engine();
        sha.input(&per_commitment_point.serialize());
        sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
@@ -185,7 +184,7 @@ pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_co
        Ok(key)
 }
 
-pub(super) fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
+pub(crate) fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
        let mut sha = Sha256::engine();
        sha.input(&per_commitment_point.serialize());
        sha.input(&base_point.serialize());
@@ -198,7 +197,7 @@ pub(super) fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>,
 /// 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<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, revocation_base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
+pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_secret: &SecretKey, revocation_base_secret: &SecretKey) -> Result<SecretKey, secp256k1::Error> {
        let revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &revocation_base_secret);
        let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
 
@@ -225,7 +224,7 @@ pub(super) fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Se
        Ok(part_a)
 }
 
-pub(super) fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, revocation_base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
+pub(crate) fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, revocation_base_point: &PublicKey) -> Result<PublicKey, secp256k1::Error> {
        let rev_append_commit_hash_key = {
                let mut sha = Sha256::engine();
                sha.input(&revocation_base_point.serialize());
@@ -263,11 +262,9 @@ pub struct TxCreationKeys {
        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,
 }
 impl_writeable!(TxCreationKeys, 33*6,
-       { per_commitment_point, revocation_key, a_htlc_key, b_htlc_key, a_delayed_payment_key, b_payment_key });
+       { per_commitment_point, revocation_key, a_htlc_key, b_htlc_key, a_delayed_payment_key });
 
 /// One counterparty's public keys which do not change over the life of a channel.
 #[derive(Clone, PartialEq)]
@@ -280,9 +277,10 @@ pub struct ChannelPublicKeys {
        /// a commitment transaction so that their counterparty can claim all available funds if they
        /// broadcast an old state.
        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 which receives our immediately spendable primary channel balance in
+       /// remote-broadcasted commitment transactions. 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).
@@ -295,28 +293,27 @@ pub struct ChannelPublicKeys {
 impl_writeable!(ChannelPublicKeys, 33*5, {
        funding_pubkey,
        revocation_basepoint,
-       payment_basepoint,
+       payment_point,
        delayed_payment_basepoint,
        htlc_basepoint
 });
 
 
 impl TxCreationKeys {
-       pub(crate) fn new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, 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<TxCreationKeys, secp256k1::Error> {
+       pub(crate) fn new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, a_delayed_payment_base: &PublicKey, a_htlc_base: &PublicKey, b_revocation_base: &PublicKey, b_htlc_base: &PublicKey) -> Result<TxCreationKeys, secp256k1::Error> {
                Ok(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)?,
                })
        }
 }
 
 /// 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 {
+pub(crate) fn get_revokeable_redeemscript(revocation_key: &PublicKey, to_self_delay: u16, delayed_payment_key: &PublicKey) -> Script {
        Builder::new().push_opcode(opcodes::all::OP_IF)
                      .push_slice(&revocation_key.serialize())
                      .push_opcode(opcodes::all::OP_ELSE)
@@ -364,7 +361,7 @@ pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit
        if htlc.offered {
                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)
@@ -392,7 +389,7 @@ pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit
        } else {
                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)
@@ -538,7 +535,6 @@ impl LocalCommitmentTransaction {
                                        a_htlc_key: dummy_key.clone(),
                                        b_htlc_key: dummy_key.clone(),
                                        a_delayed_payment_key: dummy_key.clone(),
-                                       b_payment_key: dummy_key.clone(),
                                },
                        feerate_per_kw: 0,
                        per_htlc: Vec::new()