Password Cracking

Objectives

This is a practice project to help you learn C#. Your goal is to make a very simple password cracking program. While you may think of password cracking as something that an attacker does, this is actually a useful thing for a legitimate website to do — if your user’s passwords are easily cracked, then maybe an attacker will be able to get in easily!

Project Setup

Follow the instructions in this short tutorial. You should:

• Install Visual Studio Code if you haven’t already.
• Install the C# Dev Kit extension.
• Create the Hello World app.

After you have done this, convert the Hello World app to be object-oriented:

using System;

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Hello Again!");
    }
}

Practice both running and debugging the code.

Project

Now write a simple password cracker. This program should:

• Load a file containing words in the dictionary
• Prompt the user for their password
• Check the password against every password in the dictionary, and print the password if it is found.
• Print “Not Found” if not found.

Be sure to create a new project for this, instead of re-using the hello world projet.

To write this code, you may find the following resources helpful:

• A tour of the C# language.

• [A dictionary of American English words](http://wordlist.aspell.net/12dicts/](http://wordlist.aspell.net/12dicts/). You can use the file in American/2of12.txt.

• Read the lines in a file.

• Ask for user input.

• Import a cryptography library and use it to hash a word.

• Since hashing uses a byte array, convert a string into an array of bytes.

• Compare two hashes.

If you would like to go farther, you may also want to try checking for common substitutions that people use to disguise their password, such as:

• a -> @
• l -> 1
• e -> 3