function hexStringToUint8Array(hexString)
{
    if (hexString.length % 2 != 0)
        throw "Invalid hexString";
    var arrayBuffer = new Uint8Array(hexString.length / 2);

    for (var i = 0; i < hexString.length; i += 2) {
        var byteValue = parseInt(hexString.substr(i, 2), 16);
        if (byteValue == NaN)
            throw "Invalid hexString";
        arrayBuffer[i/2] = byteValue;
    }

    return arrayBuffer;
}
function bytesToHexString(bytes)
{
    if (!bytes)
        return null;

    bytes = new Uint8Array(bytes);
    var hexBytes = [];

    for (var i = 0; i < bytes.length; ++i) {
        var byteString = bytes[i].toString(16);
        if (byteString.length < 2)
            byteString = "0" + byteString;
        hexBytes.push(byteString);
    }

    return hexBytes.join("");
}
function asciiToUint8Array(str)
{
    var chars = [];
    for (var i = 0; i < str.length; ++i)
        chars.push(str.charCodeAt(i));
    return new Uint8Array(chars);
}
function bytesToASCIIString(bytes)
{
    return String.fromCharCode.apply(null, new Uint8Array(bytes));
}
function failAndLog(error)
{
    console.log(error);
}