f - pass Nonce instead of IV

Author: jkczyz

lightning/src/ln/inbound_payment.rs

@@ -89,8 +89,8 @@ impl ExpandedKey {
 
 	/// Encrypts or decrypts the given `bytes`. Used for data included in an offer message's
 	/// metadata (e.g., payment id).
-	pub(crate) fn crypt_for_offer(&self, mut bytes: [u8; 32], iv_bytes: &[u8; IV_LEN]) -> [u8; 32] {
-		let chacha_block = ChaCha20::get_single_block(&self.offers_encryption_key, iv_bytes);
+	pub(crate) fn crypt_for_offer(&self, mut bytes: [u8; 32], nonce: Nonce) -> [u8; 32] {
+		let chacha_block = ChaCha20::get_single_block(&self.offers_encryption_key, &nonce.0);
 		for i in 0..bytes.len() {
 			bytes[i] = chacha_block[i] ^ bytes[i];
 		}

lightning/src/offers/signer.rs

@@ -167,7 +167,7 @@ impl MetadataMaterial {
 	) -> Self {
 		// Encrypt payment_id
 		let encrypted_payment_id = payment_id.map(|payment_id| {
-			expanded_key.crypt_for_offer(payment_id.0, &nonce.0)
+			expanded_key.crypt_for_offer(payment_id.0, nonce)
 		});
 
 		Self {
@@ -254,7 +254,7 @@ pub(super) fn verify_payer_metadata<'a, T: secp256k1::Signing>(
 	)?;
 
 	let nonce = Nonce::try_from(&metadata[PaymentId::LENGTH..][..Nonce::LENGTH]).unwrap();
-	let payment_id = expanded_key.crypt_for_offer(encrypted_payment_id, &nonce.0);
+	let payment_id = expanded_key.crypt_for_offer(encrypted_payment_id, nonce);
 
 	Ok(PaymentId(payment_id))
 }