From: Chris Duncan <chris@codecow.com>
Date: Thu, 3 Sep 2026 05:17:45 +0000 (-0700)
Subject: Expand unit tests for equalbytes.
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=94457aaa9f7098ac84f5af1abd8b3ec40cce3360;p=nano25519.git

Expand unit tests for equalbytes.
---

diff --git a/src/assembly/tests.ts b/src/assembly/tests.ts
index fef7ee7..2e56d66 100644
--- a/src/assembly/tests.ts
+++ b/src/assembly/tests.ts
@@ -6,16 +6,39 @@ import { equalbytes } from './utils'
 /**
  * Tests run on initialization to ensure build is correct.
  */
-const testbytesA = new StaticArray<u8>(32).fill(0)
-const testbytesB = new StaticArray<u8>(32).fill(0)
 
-/** equalbytes */
+/**
+ * equalbytes - checks masked bytes against the following test keys:
+ * - random bytes
+ * - all zeros
+ * - all ones
+ */
+const zeros = new StaticArray<u8>(32).fill(0)
+const ones = new StaticArray<u8>(32).fill(255)
+const random = new StaticArray<u8>(32)
 for (let i = 0; i < 32; i++) {
-	for (let j: u8 = 0; j < 8; j++) {
-		testbytesA[i] = 1 << j
-		if (equalbytes(testbytesA, testbytesB, 32)) {
-			throw new Error('equalbytes failed build test')
+	random[i] = u8(Math.random() * 255)
+}
+
+const vectors = ['zeros', 'ones', 'random',]
+const expecteds = [zeros, ones, random,]
+
+const actual = new StaticArray<u8>(32)
+
+for (let i = 0; i < vectors.length; i++) {
+	const vector = vectors[i]
+	const expected = expecteds[i]
+	memory.copy(changetype<usize>(actual), changetype<usize>(expected), 32)
+	for (let i = 0; i < 32; i++) {
+		if (!equalbytes(actual, expected, 32)) {
+			throw new Error(`equalbytes build error: ${vector} failed instead of passing (expected [${expected}], actual [${actual}])`)
+		}
+		for (let j: u8 = 1; j < 255; j++) {
+			actual[i] ^= j
+			if (equalbytes(actual, expected, 32)) {
+				throw new Error(`equalbytes build error: ${vector} passed instead of failing (expected [${expected}], actual [${actual}])`)
+			}
+			actual[i] = expected[i]
 		}
-		testbytesA[i] = 0
 	}
 }
diff --git a/src/lib/wasm.ts b/src/lib/wasm.ts
index 50f4bf1..6f95e93 100644
--- a/src/lib/wasm.ts
+++ b/src/lib/wasm.ts
@@ -51,6 +51,7 @@ const module = new WebAssembly.Module(wasm)
 export const { exports } = new WebAssembly.Instance(module, {
 	env: {
 		memory,
+		seed: (): number => new Float64Array((crypto.getRandomValues(new BigUint64Array(1)).buffer))[0],
 		abort: (msg: any, file: any, row: any, col: any): never => {
 			const getString = (pointer: number): string | null => {
 				const end = pointer + new Uint32Array(memory.buffer)[pointer - 4 >>> 2] >>> 1