Crypto-Js 3.0
by Miguel Roman
HTML
<script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/index.js"></script>
<p id="value"></p>JavaScript
var params = '';
var key = '';
var signature = CryptoJS.HmacSHA256(params, key);
var value = CryptoJS.enc.Base64.stringify(signature);
document.getElementById('value').innerHTML = value;