Question

Write a password cracker program for the passwords created according to the policy outlined in assignment 15 (exactly 8 characters: 5 letters and 3 digits). You are to write a function that takes one parameter that is a hash of a password and should return a possible password (a string) that has the same hash. Use python secure hash function sha1 from hashlib module. Hint: brute force method will be more than adequate to the task.  

Please I need it as python program

Answer 1

import hashlib


# function takes one parameter that is a hash of a password
# returns a possible password (a string) that has the same hash
def get_password(password_hash):
    # use brute force method to crack the password
    # password is exactly 8 characters: 5 letters and 3 digits
    password = [0, 0, 0, 0, 0, 0, 0, 0]  # create a password array of size 8
    possible_letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    # create password with all possible combinations
    # loop 8 times for 8 character in password
    # loop for all possible letters
    for ch1 in possible_letters:
        password[0] = ch1
        for ch2 in possible_letters:
            password[1] = ch2
            for ch3 in possible_letters:
                password[2] = ch3
                for ch4 in possible_letters:
                    password[3] = ch4
                    for ch5 in possible_letters:
                        password[4] = ch5
                        for ch6 in possible_letters:
                            password[5] = ch6
                            for ch7 in possible_letters:
                                password[6] = ch7
                                for ch8 in possible_letters:
                                    password[7] = ch8
                                    # convert array into string
                                    string = ""
                                    for i in range(8):
                                        string = string + password[i]
                                    # create a hash for the string
                                    string_hash = hashlib.sha1(string.encode())
                                    # now compare string hash and password hash
                                    if string_hash.digest() == password_hash.digest():
                                        # return the string as it is the password
                                        return string


# main method to run the program
def main():
    # create a password (with 5 letters and 3 digits) to hash
    password = "aR3fg57Q"
    # hash the password by using sha1 function
    password_hash = hashlib.sha1(password.encode())
    # crack the password using our function
    cracked_password = get_password(password_hash)
    # print the password
    print(cracked_password)


if __name__ == '__main__':
    main()