Udp.Main C# (CSharp) Method

    static void Main(string[] args)
    {
        string serverIp;
        int httpPort;
        int serverPort;
        const string STOP = "stop";

        Console.WriteLine("Enter server IP address:");

        serverIp = Console.ReadLine();

        Console.WriteLine("Enter HTTP port number:");

        httpPort = int.Parse(Console.ReadLine());

        Console.WriteLine("Connection to {0}:{1}", serverIp, httpPort);

        var request = (HttpWebRequest)WebRequest.Create("http://" + serverIp + ":" + httpPort + "/auth");
        var postData = "thing1=hello";
        postData += "&thing2=world";
        var data = Encoding.ASCII.GetBytes(postData);
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = data.Length;
        var stream = request.GetRequestStream();
        stream.Write(data, 0, data.Length);
        var response = (HttpWebResponse)request.GetResponse();
        var authRes = new StreamReader(response.GetResponseStream()).ReadToEnd();

        Console.WriteLine("Auth response:{0}", authRes);

        JSONNode auth = JSON.Parse(authRes);

        Console.WriteLine("Session ID is {0}", auth["sessionId"]);
        Console.WriteLine(
            "Cipher Key, Nonce, and MacKey:{0}, {1}, {2}",
            auth["cipherData"]["base64"]["cipherKey"],
            auth["cipherData"]["base64"]["cipherNonce"],
            auth["cipherData"]["base64"]["macKey"]
        );

        Console.WriteLine("Enter UDP server port number:");

        serverPort = int.Parse(Console.ReadLine());

        Console.WriteLine("Connection to {0}:{1}", serverIp, serverPort);

        int myPort = 54061;

        // connect to UDP server and send message
        UdpClient client = new UdpClient(myPort);
        IPEndPoint endPoint = new IPEndPoint(IPAddress.Parse(serverIp), serverPort);
        client.Connect(endPoint);

        Console.WriteLine("Prepare encryption");

        // prepare encryption
        Guid sid = new Guid(auth["sessionId"]);
        byte[] cipherKey = System.Convert.FromBase64String(auth["cipherData"]["base64"]["cipherKey"]);
        byte[] cipherNonce = System.Convert.FromBase64String(auth["cipherData"]["base64"]["cipherNonce"]);
        byte[] macKey = System.Convert.FromBase64String(auth["cipherData"]["base64"]["macKey"]);
        var crypto = new Crypto(sid, cipherKey, cipherNonce, macKey);

        byte[] packet = Encoding.ASCII.GetBytes("{\"command\":1,\"payload\":\"Hello\"}");
        var epacket = crypto.Encrypt(packet);

        client.Send(epacket, epacket.Length);

        Console.WriteLine("UDP message sent: size is {0}", epacket.Length);

        Console.WriteLine("Waiting for server message...");

        byte[] recData = client.Receive(ref endPoint);

        Console.WriteLine("Try decrypting...");

        var dpack = crypto.Decrypt(recData);

        Console.WriteLine("message from server: {0}", Encoding.UTF8.GetString(dpack));
    }