Custom, dumb, simple pow in the browser.

README.md

Inspired by https://github.com/174n/tiny-pow and is somehow way worse.

index.ts

export const computePow = async (
	data: Uint8Array,
	zero_prefix_length = 1
): Promise<ArrayBuffer> => {
	const salted = new Uint8Array(data.length + 16);
	for (let j = 0; j < data.length; j++) {
		salted[j] = data[j];
	}

	const salt = new Uint8Array(salted.buffer, data.length);
	crypto.getRandomValues(salt);

	let i = 0;
	const calcDigest = async (data: Uint8Array) => {
		return new Uint8Array(await crypto.subtle.digest('SHA-256', data)).slice(0, zero_prefix_length);
	};
	let digest = await calcDigest(salted);
	while (!digest.every((x) => x == 1)) {
		if (i++ > 999999) throw 'Failed to find answer to proof-of-work in 999999 iterations.';

		crypto.getRandomValues(salt);
		digest = await calcDigest(salted);
	}
	return salt;
};