Dry-up witnessScript in sign_remote_htlc_transaction
[rust-lightning] / lightning / src / ln / chan_utils.rs
index 9be3f38a78e6c027c7328a6d5e6c35e69013c8bd..e619716a3cc8cfea5cd4c4688da6f5dad5056729 100644 (file)
@@ -173,7 +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());
@@ -184,7 +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());
@@ -197,7 +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);
 
@@ -224,7 +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());
@@ -262,11 +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)]
@@ -279,9 +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).
@@ -294,28 +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)
@@ -537,7 +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()