First Hacking Tool - A Password Cracker (Python for Hackers Part-8)

Python’s strength lies in the robust libraries that you can use when creating your own programs. This Python program will not only teach you how you can crack passwords, but also help you learn how to embed a library in your code and get results that you want.

To write this password cracker, you will need to have a crypt() algorithm that will allow you to hash passwords that are in the UNIX format. When you launch the Python interpreter, you will actually see that the crypt library that you need for this code is already right in the standard library. Now, to compute for an encrypted hash of a UNIX password, all you need to do is to call the function crypt.crypt() and then set password and salt as parameters. The code should return with a string that contains the hashed password.

Here is how it should be done:

Now, you can try hashing a target’s password with the function crypt(). Once you are able to import the necessary library, you can now send the parameters salt “HX” and the password “egg” to the function. When you run the code, you will get a hashed password that contains the string “HX9LLTdc/jiDE”. This is how the output should look like:

When that happens, you can simply write a program that uses iteration throughout an entire dictionary, which will try against each word that will be possibly yield the word used for the password.

Now, you will need to create two functions that you can use in the program that you are going to write, which are testPass and main. The main function will pull up the file that contains the encrypted password, which is password.txt, and will then read all the contents in the lines that the password file contains. Afterwards, it will then split the lines into the hashed password and its corresponding username. After that, the main function will call the testPass function to test the hashed passwords against the dictionary.

The testPass function will take the password that is still encrypted as a parameter and then will return after exhausting the words available in the dictionary or when it has successfully decrypted the password. This is how the program will look like:

When you run this code, you will be able to see this output:

Judging from these results, you will be able to deduce that the password for the username ‘victim’ is right in the dictionary that you have available. However, the password for the username ‘root’ is a word that your dictionary does not contain. This means that the administrator’s password in the system that you are trying to exploit is more sophisticated, but can possibly be contained in another dictionary type. 

At this point, you are now able to set up an ideal hacking environment for Python and learn how to make use of available resources from other hackers. Now that you are able to create your first hacking tool, it’s time for you to discover how you can make your own hacking scripts!