How to validate a github webhook in pure Javascript using crypto.

validate_github_webhook.js

const crypto = require('crypto')

const webhookSecret = 'my-webhook-secret-that-i-put-in-github';
/**
 * 
 * @param rawBody {Buffer} the raw payload of the request
 * @param sig {string} the x-hub-signature-256 header value
 * @returns true if the signature matches
 */
const validGithubSignature = (rawBody, sig) => {
  const hmac = crypto.createHmac('sha256', webhookSecret');
	hmac.update(rawBody);
	const digest = hmac.digest('hex');
	return sig === `sha256=${digest}`;
};