Irc client Identify protocol "No Ident repsonse"

Question

My client isn't able to connect to the irc server I am trying to connect to. I did some research and it says that I need to listen on port 113 and respond back to the server in a certain format. I am not sure exactly how to do this. When I tried doing it before I got an error message. Here is the code before I tried listening. The irc sends the message to my client "No ident response". Do I need to create an entire different all together that will listen respond on port 113 or can I do it in here?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;

namespace ConnectIRC
{
    class Program
    {
        static void Main(string[] args)
        {
            string ip = "asimov.freenode.net";
            string nick = " NICK IKESBOT \r\n";
            string join = "JOIN #NetChat\r\n";
            int port = 6667;

            const int recvBufSize = 8162;
            byte[] recvbBuf = new byte[recvBufSize];
            //stores the nick
            byte[] nickBuf = Encoding.ASCII.GetBytes(nick);
            //Stores the room join
            byte[] joinBuf = Encoding.ASCII.GetBytes(join);

            Socket conn = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            conn.Connect(ip, port);

            conn.Send(nickBuf, nickBuf.Length, SocketFlags.None);
            conn.Send(joinBuf, joinBuf.Length, SocketFlags.None);


            for(;;){              
                byte[] buffer = new byte[3000];
                int rec = conn.Receive(buffer, 0, buffer.Length, 0);
                Array.Resize(ref buffer, rec);
               Console.WriteLine(Encoding.Default.GetString(buffer));
            }   
        }
    }
}

Answer 1

Despite @Saruman's answer above, you don't need to create an ident server to connect to most IRC networks (including freenode). You can completely ignore the error about "No ident response". It's an outdated technology which is no longer secure and only ever worked properly on Unix-based multiuser systems.

Your actual issue appears to be that you never finish registering the connection to the IRC server. The specification states that you need to send both USER and NICK messages:

string ip = "asimov.freenode.net";
string nick = "NICK IKESBOT \r\n";
// format is: USER <username> * * :<realname>
string user = "USER IKESBOT * * :IKESBOT\r\n";
string join = "JOIN #NetChat\r\n";
int port = 6667;

const int recvBufSize = 8162;
byte[] recvbBuf = new byte[recvBufSize];
//stores the nick
byte[] nickBuf = Encoding.ASCII.GetBytes(nick);

byte[] userBuf = Encoding.ASCII.GetBytes(user);
//Stores the room join
byte[] joinBuf = Encoding.ASCII.GetBytes(join);

Socket conn = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
conn.Connect(ip, port);

conn.Send(nickBuf, nickBuf.Length, SocketFlags.None);
conn.Send(userBuf, userBuf.Length, SocketFlags.None);
conn.Send(joinBuf, joinBuf.Length, SocketFlags.None);

(You've got an extra space before the NICK - this may or may not break things.)

---

Aside:

You may find it easier to use TcpClient, StreamReader and StreamWriter to access the underlying socket - they wrap it and deal with the buffers for you. You can then read the response line by line directly into a string, and write to the socket by just passing a string. No fiddling around with encoding and buffers.

TcpClient client = new TcpClient("chat.freenode.net", 6667);
StreamReader reader = new StreamReader(client.GetStream());
StreamWriter writer = new StreamWriter(client.GetStream());

string recievedData = reader.ReadLine();

writer.WriteLine("NICK IKESBOT");
writer.Flush();