You should already have done some brute-force attacks in previous chapters, but its important to repeat the exercise until you develop intuition for the concept. Using our preceding fake HMAC, have the computer generate a random password of specific sizes and use brute-force methods to find out what it is. To be more specific, assume that you already know what the message is (e.g., hello world, happy birthday, or a message of your choosing). Write a program to create a random password of characters, prepend the password to the message, and then print out the MAC (hash). Take the output and iterate through all possible passwords until you find the right one. Start with a simple test of a single-letter character, then try two characters, and so forth. Mix things up by using different sets of characters such as all lowercase, lowercase and uppercase, either case plus numbers, and so forth.