Proxy Style

It means that the address of such a server changes periodically. This is useful if the user wants to be as anonymous as possible when surfing the web.

To send a UDP request to a STUN server in C++, you can use the following example code. This example uses the boost::asio library for handling asynchronous I/O operations and boost::beast for handling UDP communication. Make sure you have the Boost library installed on your system before running this code.

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

namespace http = boost::beast::http;

using tcp = boost::asio::ip::tcp;
using udp = boost::asio::ip::udp;

int main(int argc, char* argv[]) {
  if (argc != 3) {
    std::cerr << "Usage: stun_udp_request  " << std::endl;
    return EXIT_FAILURE;
  }

  boost::asio::io_context ioc;
  udp::resolver resolver(ioc);
  udp::resolver::results_type results = resolver.resolve(argv[1], argv[2]);

  if (results.empty()) {
    std::cerr << "Cannot resolve: " << argv[1] << ":" << argv[2] << std::endl;
    return EXIT_FAILURE;
  }

  udp::socket udp_socket(ioc);
  udp_socket.connect(results.begin()->endpoint());

  // Prepare the STUN Binding Request
  std::string stun_request =
      "BINDING_REQUEST\r\n"
      "MIXED_RELAY\r\n"
      "USER-AGENT: STUN-UDP-Example\r\n"
      "\r\n";

  // Send the STUN Binding Request
  boost::system::error_code ignored_error;
  udp_socket.send_to(boost::asio::buffer(stun_request), results.begin()->endpoint(), 0, ignored_error);

  // Receive the STUN Binding Response
  boost::beast::flat_buffer buffer;
  http::response response;
  udp_socket.receive_message(buffer, response);

  // Print the STUN Binding Response
  std::cout << "STUN Binding Response:\n";
  std::cout << response.what() << std::endl;

  return EXIT_SUCCESS;
}

To compile the example, you can use the following command:

g++ -std=c++17 -o stun_udp_request stun_udp_request.cpp -lboost_system -lboost_as

The term "public" should be understood to mean open proxy servers. That is, they can be used by all users without exception. They can be insecure and are often quite overloaded, so the connection speed or response time when using public proxies can be very slow.

In Key Collector settings, the user can specify parameters of the proxy server through which the program will connect to the network. In the application window, first select "Settings", then go to the "Network" tab and check "Use proxy". Its parameters can be set either manually or through a configuration file.

The reason for the lack of connection to the network can be due to incorrect proxy settings, that is, incorrect IP addresses were entered or specified, or the server simply does not work. Users also often forget that proxy settings must be disabled.