function stringToUInt8Array(str) 
{
   var array = new Uint8Array(str.length);
   for (var i=0; i<str.length; i++)
		array[i] = str.charCodeAt(i);
   return array;
}
 
function uInt8ArrayToString(array) {
    var uint8array = new Uint8Array(array.buffer);
    return String.fromCharCode.apply(null, uint8array);
}

function base64EncodeUint8Array(input) {
    var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var output = "";
    var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
    var i = 0;

    while (i < input.length) {
        chr1 = input[i++];
        chr2 = i < input.length ? input[i++] : Number.NaN; // Not sure if the index
        chr3 = i < input.length ? input[i++] : Number.NaN; // checks are needed here

        enc1 = chr1 >> 2;
        enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
        enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
        enc4 = chr3 & 63;

        if (isNaN(chr2)) {
            enc3 = enc4 = 64;
        } else if (isNaN(chr3)) {
            enc4 = 64;
        }
        output += keyStr.charAt(enc1) + keyStr.charAt(enc2) +
            keyStr.charAt(enc3) + keyStr.charAt(enc4);
    }
    return output;
}