From: Chris Duncan <chris@zoso.dev>
Date: Mon, 18 Aug 2025 14:20:45 +0000 (-0700)
Subject: Refactor vn and document behavior.
X-Git-Tag: v0.10.5~41^2~76
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=380951c8ad3eeeeba470b9066707f70c3818f343;p=libnemo.git

Refactor vn and document behavior.
---

diff --git a/src/lib/crypto/nano-nacl.ts b/src/lib/crypto/nano-nacl.ts
index 63273a0..9d6d1b9 100644
--- a/src/lib/crypto/nano-nacl.ts
+++ b/src/lib/crypto/nano-nacl.ts
@@ -26,12 +26,17 @@ export class NanoNaCl {
 	static I: Float64Array = new Float64Array([0xa0b0, 0x4a0e, 0x1b27, 0xc4ee, 0xe478, 0xad2f, 0x1806, 0x2f43, 0xd7a7, 0x3dfb, 0x0099, 0x2b4d, 0xdf0b, 0x4fc1, 0x2480, 0x2b83])
 	static XY: Float64Array = new Float64Array([0xdd90, 0xa5b7, 0x8ab3, 0x6dde, 0x52f5, 0x7751, 0x9f80, 0x20f0, 0xe37d, 0x64ab, 0x4e8e, 0x66ea, 0x7665, 0xd78b, 0x5f0f, 0xe787])
 
-	static #vn (x: Uint8Array, xi: number, y: Uint8Array, yi: number, n: number): number {
+	/**
+	* Checks first 32 bytes of two byte arrays to see if they are equivalent.
+	*
+	* @returns 0 if first 32 bytes are equal, else 1 if there is at least one bit difference
+	*/
+	static #vn (x: Uint8Array, y: Uint8Array): number {
 		let d: number = 0
-		for (let i = 0; i < n; i++) {
-			d |= x[xi + i] ^ y[yi + i]
+		for (let i = 0; i < 32; i++) {
+			d |= x[i] ^ y[i]
 		}
-		return (1 & ((d - 1) >>> 8)) - 1
+		return ((1 & ((d - 1) >>> 8)) - 1) & 1
 	}
 
 	static pow2523 (out: Float64Array, i: Float64Array): void {
@@ -82,7 +87,7 @@ export class NanoNaCl {
 		const d: Uint8Array = new Uint8Array(32)
 		this.pack25519(c, a)
 		this.pack25519(d, b)
-		return this.#vn(c, 0, d, 0, 32)
+		return this.#vn(c, d)
 	}
 
 	static pack25519 (out: Uint8Array, n: Float64Array): void {