EonaCat.Connections/README.md

EonaCat.Connections

.NET Framework 4.8+ / .NET (Core) compatible library providing high-throughput TCP/UDP servers and clients with optional TLS (for TCP) and optional application-layer encryption (TCP/UDP).

Design goals:

• High performance and low latency
• Scalable to tens of thousands of concurrent connections
• Scalable socket I/O via SocketAsyncEventArgs (SAEA) for raw TCP and UDP
• TLS (SSL) over TCP using SslStream (built-in)
• Optional encryption (AES-CBC + PBKDF2_SHA256) for TCP/UDP payloads
• Minimal allocations, event-driven callbacks

- For highest throughput, run x64, enable LargePage, set appropriate Socket options and OS registry tuning.

Generate self-signed certificate for TLS (TCP):

Run as Administrator

$cert = New-SelfSignedCertificate `
    -DnsName "localhost" `
    -CertStoreLocation "Cert:\LocalMachine\My" `
    -KeyExportPolicy Exportable `
    -NotAfter (Get-Date).AddYears(5) `
    -FriendlyName "EonaCat Connections Test Certificate"

$password = ConvertTo-SecureString -String "p@ss" -Force -AsPlainText

Export-PfxCertificate `
    -Cert "Cert:\LocalMachine\My\$($cert.Thumbprint)" `
    -FilePath "C:\temp\server.pfx" `
    -Password $password

This will create a self-signed certificate with the password 'p@ss' in the folder C:\temp\server.pfx.

Server example:

using EonaCat.Connections.Models;

namespace EonaCat.Connections.Server.Example
{
    // This file is part of the EonaCat project(s) which is released under the Apache License.
    // See the LICENSE file or go to https://EonaCat.com/license for full license details.

    public class Program
    {
        private static NetworkServer _server;

        public static void Main(string[] args)
        {
            CreateServerAsync().ConfigureAwait(false);

            while (true)
            {
                Console.Write("Enter message to send (or 'exit' to quit): ");
                var message = Console.ReadLine();
                if (!string.IsNullOrEmpty(message) && message.Equals("exit", StringComparison.OrdinalIgnoreCase))
                {
                    _server.Stop();
                    _server.Dispose();
                    Console.WriteLine("Server stopped.");
                    break;
                }

                if (!string.IsNullOrEmpty(message))
                {
                    _server.BroadcastAsync(message).ConfigureAwait(false);
                }
            }
        }

        private static async Task CreateServerAsync()
        {
            var config = new Configuration
            {
                Protocol = ProtocolType.TCP,
                Port = 1111,
                UseSsl = true,
                UseAesEncryption = true,
                MaxConnections = 100000,
                AesPassword = "EonaCat.Connections.Password",
                Certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2("server.pfx", "p@ss")
            };

            _server = new NetworkServer(config);

            // Subscribe to events
            _server.OnConnected += (sender, e) =>
                Console.WriteLine($"Client {e.ClientId} connected from {e.RemoteEndPoint}");

            _server.OnConnectedWithNickname += (sender, e) =>
                Console.WriteLine($"Client {e.ClientId} connected with nickname: {e.Nickname}");

            _server.OnDataReceived += async (sender, e) =>
            {
                if (e.HasNickname)
                {
                    Console.WriteLine($"Received from {e.Nickname}: {(e.IsBinary ? $"{e.Data.Length} bytes" : e.StringData)}");
                }
                else
                {
                    Console.WriteLine($"Received from {e.ClientId}: {(e.IsBinary ? $"{e.Data.Length} bytes" : e.StringData)}");
                }                    

                // Echo back the message
                if (e.IsBinary)
                {
                    await _server.SendToClientAsync(e.ClientId, e.Data);
                }
                else
                {
                    await _server.SendToClientAsync(e.ClientId, $"Echo: {e.StringData}");
                }
            };

            _server.OnDisconnected += (sender, e) =>
            {
                if (e.HasNickname)
                {
                    Console.WriteLine($"Client {e.Nickname} disconnected");
                }
                else
                {
                    Console.WriteLine($"Client {e.ClientId} disconnected");
                }
            };

            await _server.StartAsync();
        }
    }
}

Client example:

using EonaCat.Connections.Models;

namespace EonaCat.Connections.Client.Example
{
    // This file is part of the EonaCat project(s) which is released under the Apache License.
    // See the LICENSE file or go to https://EonaCat.com/license for full license details.

    public class Program
    {
        private static NetworkClient _client;

        public static async Task Main(string[] args)
        {
            await CreateClientAsync().ConfigureAwait(false);

            while (true)
            {
                if (!_client.IsConnected)
                {
                    await Task.Delay(1000).ConfigureAwait(false);
                    continue;
                }

                Console.Write("Enter message to send (or 'exit' to quit): ");
                var message = Console.ReadLine();

                if (!string.IsNullOrEmpty(message) && message.Equals("exit", StringComparison.OrdinalIgnoreCase))
                {
                    await _client.DisconnectAsync().ConfigureAwait(false);
                    break;
                }

                if (!string.IsNullOrEmpty(message))
                {
                    await _client.SendAsync(message).ConfigureAwait(false);
                }
            }
        }

        private static async Task CreateClientAsync()
        {
            var config = new Configuration
            {
                Protocol = ProtocolType.TCP,
                Host = "127.0.0.1",
                Port = 1111,
                UseSsl = true,
                UseAesEncryption = true,
                AesPassword = "EonaCat.Connections.Password",
                Certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2("client.pfx", "p@ss"),
            };

            _client = new NetworkClient(config);

            _client.OnGeneralError += (sender, e) =>
                Console.WriteLine($"Error: {e.Message}");

            // Subscribe to events
            _client.OnConnected += async (sender, e) =>
            {
                Console.WriteLine($"Connected to server at {e.RemoteEndPoint}");

                // Set nickname
                await _client.SetNicknameAsync("TestUser");

                // Send a message
                await _client.SendAsync("Hello server!");
            };

            _client.OnDataReceived += (sender, e) =>
                Console.WriteLine($"Server says: {(e.IsBinary ? $"{e.Data.Length} bytes" : e.StringData)}");

            _client.OnDisconnected += (sender, e) =>
            {
                Console.WriteLine("Disconnected from server");
            };

            Console.WriteLine("Connecting to server...");
            await _client.ConnectAsync();
        }
    }
}