toBase64 & fromBase64 functions for front end javascript

front_end_JS_toBase64_fromBase64

// grr why is base64 encoding not easier in frontend js?

var fromBase64 = function fromBase64(base64) {
    var raw = window.atob(base64);
    var rawLength = raw.length;
    var ab = new ArrayBuffer(rawLength);
    var array = new Uint8Array(ab);
    for (var i = 0; i < rawLength; i++) {
        array[i] = raw.charCodeAt(i);
    }
    return ab;
};

var toBase64 = function(ab) {
    var raw = "";
    var array = new Uint8Array(ab);
    for (var i = 0; i < array.length; i++) {
        raw = raw + String.fromCharCode(array[i]);
    }
    return window.btoa(raw);
};