python – How to create a brute-force password cracker for alphabetical and alphanumerical passwords?

python – How to create a brute-force password cracker for alphabetical and alphanumerical passwords?

Heres a naiive brute force method that will guess numbers (string.digits) and lower case letters (string.ascii_lowercase). You can use itertools.product with repeat set to the current password length guessed. You can start at 1 character passwords (or whatever your lower bound is) then cap it at a maximum length too. Then just return when you find the match.

import itertools
import string

def guess_password(real):
    chars = string.ascii_lowercase + string.digits
    attempts = 0
    for password_length in range(1, 9):
        for guess in itertools.product(chars, repeat=password_length):
            attempts += 1
            guess = .join(guess)
            if guess == real:
                return password is {}. found in {} guesses..format(guess, attempts)
            # uncomment to display attempts, though will be slower
            #print(guess, attempts)

print(guess_password(abc))

Output

a 1
b 2
c 3
d 4
...
aba 1369
abb 1370
password is abc. found in 1371 guesses.

One possible option which would preserve almost exactly your current code is to convert to base 36 with the following digits: 0-9a-z. This will give you every possible alpha-numeric combination for n characters if you search in range(36**n).

Using a simplified function from How to convert an integer in any base to a string?:

def baseN(num, b=36, numerals=0123456789abcdefghijklmnopqrstuvwxyz):
    return ((num == 0) and numerals[0]) or (baseN(num // b, b, numerals).lstrip(numerals[0]) + numerals[num % b])

You can then loop through numbers as in your example:

>>> for i in range(10000, 10005):
...     print(baseN(i).zfill(5))
...
007ps
007pt
007pu
007pv
007pw

To get all 3-letter possibilities, you can loop as follows:

for i in range(36**3):
    possible = baseN(i).zfill(3)

python – How to create a brute-force password cracker for alphabetical and alphanumerical passwords?