decodeCredentials.js

// decode credentials upon receiving them from store
function decodeCredentials(crd){
	// decrypt it first
	const dec = CryptoJS.AES.decrypt(crd, saltCredentials).toString(CryptoJS.enc.Utf8);
	// extract the creds length and pepper step
	const len = dec.charCodeAt(0) - 96;
	const step = dec.charCodeAt(1) - 96;
	let i = 0, j = 2, d = [];

	// extract the pepper from the salt
	while( i < len ){
		d[i++] = dec[j];
		j += step;
	}
	// return the json object
	return JSON.parse(d.join(''));
}