From: Chris Duncan <chris@zoso.dev>
Date: Sat, 22 Aug 2026 06:28:17 +0000 (-0700)
Subject: Revert to retrieving message buffer directly in wasm since it is fully synchronous... 
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=165e9953d7f954450f2d26fae19436445e7504e0;p=nano25519.git

Revert to retrieving message buffer directly in wasm since it is fully synchronous, has no re-entry points from host JS, and is never written but only read by Blake2b.
---

diff --git a/src/assembly/index.ts b/src/assembly/index.ts
index 38f8250..3541dc2 100644
--- a/src/assembly/index.ts
+++ b/src/assembly/index.ts
@@ -63,7 +63,6 @@ export function derive (): void {
 	derive_pub.fill(0)
 }
 
-const sign_msg = new StaticArray<u8>(MESSAGE_BUFFER_BYTES)
 const sign_prv = new StaticArray<u8>(PRIVATEKEY_BYTES)
 const sign_pub = new StaticArray<u8>(PUBLICKEY_BYTES)
 const sign_sig = new StaticArray<u8>(SIGNATURE_BYTES)
@@ -86,7 +85,6 @@ export function sign (mlen: i32): void {
 	}
 
 	// Clear local buffers
-	sign_msg.fill(0)
 	sign_prv.fill(0)
 	sign_pub.fill(0)
 	sign_sig.fill(0)
@@ -97,12 +95,10 @@ export function sign (mlen: i32): void {
 	INPUT_BUFFER.fill(0)
 
 	// Copy message buffer to local variable, then clear message buffer
-	memory.copy(changetype<usize>(sign_msg), changetype<usize>(MESSAGE_BUFFER), mlen)
-	MESSAGE_BUFFER.fill(0)
 
 	// Sign, then clear local input
-	crypto_sign(sign_sig, sign_msg, mlen, sign_prv, sign_pub)
-	sign_msg.fill(0)
+	crypto_sign(sign_sig, MESSAGE_BUFFER, mlen, sign_prv, sign_pub)
+	MESSAGE_BUFFER.fill(0)
 	sign_prv.fill(0)
 	sign_pub.fill(0)
 
@@ -114,7 +110,6 @@ export function sign (mlen: i32): void {
 	sign_sig.fill(0)
 }
 
-const verify_msg = new StaticArray<u8>(MESSAGE_BUFFER_BYTES)
 const verify_pub = new StaticArray<u8>(PUBLICKEY_BYTES)
 const verify_sig = new StaticArray<u8>(SIGNATURE_BYTES)
 /**
@@ -137,7 +132,6 @@ export function verify (mlen: i32): i32 {
 	}
 
 	// Clear local buffers
-	verify_msg.fill(0)
 	verify_pub.fill(0)
 	verify_sig.fill(0)
 
@@ -147,12 +141,10 @@ export function verify (mlen: i32): i32 {
 	INPUT_BUFFER.fill(0)
 
 	// Copy message buffer to local variable, then clear message buffer
-	memory.copy(changetype<usize>(verify_msg), changetype<usize>(MESSAGE_BUFFER), mlen)
-	MESSAGE_BUFFER.fill(0)
 
 	// Verify, then clear local input
-	const verified = crypto_verify(verify_sig, verify_msg, mlen, verify_pub)
-	verify_msg.fill(0)
+	const verified = crypto_verify(verify_sig, MESSAGE_BUFFER, mlen, verify_pub)
+	MESSAGE_BUFFER.fill(0)
 	verify_pub.fill(0)
 	verify_sig.fill(0)