f - cache message digest

Author: jkczyz

lightning/src/offers/invoice.rs

@@ -383,7 +383,7 @@ impl<'a> UnsignedInvoice<'a> {
 	/// This is not exported to bindings users as functions aren't currently mapped.
 	pub fn sign<F, E>(self, sign: F) -> Result<Invoice, SignError<E>>
 	where
-		F: FnOnce(TaggedBytes, &[u8]) -> Result<Signature, E>
+		F: FnOnce(&TaggedBytes, &[u8]) -> Result<Signature, E>
 	{
 		// Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 		// have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or

lightning/src/offers/invoice_request.rs

@@ -354,7 +354,7 @@ impl<'a> UnsignedInvoiceRequest<'a> {
 	/// This is not exported to bindings users as functions are not yet mapped.
 	pub fn sign<F, E>(self, sign: F) -> Result<InvoiceRequest, SignError<E>>
 	where
-		F: FnOnce(TaggedBytes, &[u8]) -> Result<Signature, E>
+		F: FnOnce(&TaggedBytes, &[u8]) -> Result<Signature, E>
 	{
 		// Use the offer bytes instead of the offer TLV stream as the offer may have contained
 		// unknown TLV records, which are not stored in `OfferContents`.

lightning/src/offers/merkle.rs

@@ -12,6 +12,7 @@
 use bitcoin::hashes::{Hash, HashEngine, sha256};
 use bitcoin::secp256k1::{Message, PublicKey, Secp256k1, self};
 use bitcoin::secp256k1::schnorr::Signature;
+use core::cell::RefCell;
 use crate::io;
 use crate::util::ser::{BigSize, Readable, Writeable, Writer};
 
@@ -28,17 +29,18 @@ tlv_stream!(SignatureTlvStream, SignatureTlvStreamRef, SIGNATURE_TYPES, {
 pub struct TaggedBytes<'a> {
 	tag: &'a str,
 	bytes: &'a [u8],
+	digest: RefCell<Option<Message>>,
 }
 
 impl<'a> TaggedBytes<'a> {
 	/// Creates tagged bytes with the given parameters.
 	pub fn new(tag: &'a str, bytes: &'a [u8]) -> Self {
-		Self { tag, bytes }
+		Self { tag, bytes, digest: RefCell::new(None) }
 	}
 
 	/// Returns the digest to sign.
 	pub fn digest(&self) -> Message {
-		message_digest(self.tag, self.bytes)
+		*self.digest.borrow_mut().get_or_insert_with(|| message_digest(self.tag, self.bytes))
 	}
 }
 
@@ -62,9 +64,9 @@ pub(super) fn sign_message<F, E>(
 	sign: F, message: TaggedBytes, metadata: &[u8], pubkey: PublicKey,
 ) -> Result<Signature, SignError<E>>
 where
-	F: FnOnce(TaggedBytes, &[u8]) -> Result<Signature, E>
+	F: FnOnce(&TaggedBytes, &[u8]) -> Result<Signature, E>
 {
-	let signature = sign(message, metadata).map_err(|e| SignError::Signing(e))?;
+	let signature = sign(&message, metadata).map_err(|e| SignError::Signing(e))?;
 
 	let pubkey = pubkey.into();
 	let secp_ctx = Secp256k1::verification_only();

lightning/src/offers/test_utils.rs

@@ -25,7 +25,7 @@ pub(super) fn payer_keys() -> KeyPair {
 	KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
 }
 
-pub(super) fn payer_sign(message: TaggedBytes, _metadata: &[u8]) -> Result<Signature, Infallible> {
+pub(super) fn payer_sign(message: &TaggedBytes, _metadata: &[u8]) -> Result<Signature, Infallible> {
 	let secp_ctx = Secp256k1::new();
 	let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 	Ok(secp_ctx.sign_schnorr_no_aux_rand(&message.digest(), &keys))
@@ -41,7 +41,7 @@ pub(super) fn recipient_keys() -> KeyPair {
 }
 
 pub(super) fn recipient_sign(
-	message: TaggedBytes, _metadata: &[u8]
+	message: &TaggedBytes, _metadata: &[u8]
 ) -> Result<Signature, Infallible> {
 	let secp_ctx = Secp256k1::new();
 	let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());