|
Java™
by example!
|
|
|
How do I connect to the daytime port (13)?
The daytime port 13 will return a datagram containing the server time.
On many systems, this port is being disabled, fearing hackers may use it to perform a denial-of-service attack of some sort. Based on the date format that the server returns, the hacker may also find out about the operating system.
Just open a socket and read a line. It will contain the server time if the port is enabled.
DaytimeClient.java:
import java.util.*;
import java.net.*;
import java.io.*;
public class DaytimeClient {
public static void main(String args[]) {
if (args.length != 1) {
System.out.println("java DaytimeClient <server>");
System.exit(1);
}
try {
Socket socket = new Socket(args[0], 13); // 7 is echo port
BufferedReader br = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
String ret = br.readLine();
System.out.println(ret);
socket.close();
}
catch(Exception e) {
e.printStackTrace();
}
}
}
|
Further Information
Author of answer: Joris Van den Bogaert
Comments to this answer are only viewable by members. Login or become a member!
|
|
|
|
|
In-house 