cryptoUtils.js

const sha256 = async (body) => {
	const enc = new TextEncoder();
	const hashBuffer = await crypto.subtle.digest("SHA-256", enc.encode(body));
	return new Uint8Array(hashBuffer);
}

const hmacSha256 = async (body, secret) => {
	// similar to https://stackoverflow.com/a/74428751/319229
		const enc = new TextEncoder();
		const algorithm = { name: "HMAC", hash: "SHA-256" };
		if (!(secret instanceof Uint8Array)) {
			secret = enc.encode(secret);
		}
		const key = await crypto.subtle.importKey(
			"raw",
			secret,
			algorithm,
			false,
			["sign", "verify"]
		);

		const signature = await crypto.subtle.sign(
			algorithm.name,
			key,
			enc.encode(body)
		);

		return new Uint8Array(signature);
}

const hex = (buffer) => {
	const hashArray = Array.from(buffer);
	
	// convert bytes to hex string
	const digest = hashArray
		.map((b) => b.toString(16).padStart(2, "0"))
		.join("");

	return digest;
}

const generateSecret = (bytes) => {
	return hex(crypto.getRandomValues(new Uint8Array(bytes)));
}


export { sha256, hmacSha256, hex, generateSecret }