KSocks5

Standard Socks5 Server implementation in Java

Features

• TCP Streaming, Bind
• Username/Password Authentication
• Intercept/Monitor incoming clients and connections
• Reverse Proxy

Written in pure Java, no additional libraries, requires Java >= 8

Setup

<dependency>
    <groupId>space.themelon</groupId>
    <artifactId>KSocks5</artifactId>
    <version>1.1</version>
</dependency>

implementation("space.themelon:KSocks5:1.1")

Usage

• Spawn a simple open proxy server

ProxyServer server = new ProxyServer.Builder(port).build();
...
server.close();

• Create a proxy server with Username / Password Authentication

AuthMode userPassAuth = new AuthMode((username, password) -> 
    username.equals("secureusername") && password.equals("securepassword"));

ProxyServer proxy = new ProxyServer.Builder(port)
    .auth(userPassAuth)
    .build();

• Monitor incoming client connections (clientMonitor)

ClientCallback monitor = address -> {
  System.out.println("New client " + address);
  return true; // approve client
};
ProxyServer server = new ProxyServer.Builder(port)
    .clientMonitor(monitor)
    .build();

• Monitor outgoing connection requests (connectionMonitor)

ConnectionCallback monitor = (client, destination, port) -> {
  if (isBlacklisted(destination)) {
    System.out.println("Blocking connection to " + destination);
    return false;
  }
  return true;
};

ProxyServer server = new ProxyServer.Builder(port)
    .connectionMonitor(monitor)
    .build();

• Create a reverse proxy to outside, rather than awaiting connection

ProxyServer server = new ProxyServer.Builder(remoteHost, remotePort)
    .reverseProxy()
    .build();