regular_zips.py

import re
import os, shutil, pathlib
from zipfile import ZipFile, BadZipFile
from string import ascii_uppercase, ascii_lowercase

whitespace = ["\r", "\n", "\t", "\f", "\v", " "]

rep_var = ["{i}", "{j}", "{k}"]

def solve_challenge():
    with open("hint.txt", "r") as f:
        regex = f.read()[1:-1]

    print(regex)

    count = 0
    while regex.find("[a-z]") != -1:
        regex = regex.replace("[a-z]", rep_var[count], 1)
        count += 1
        if count == 1:
            i_iter = ascii_lowercase
        elif count == 2:
            j_iter = ascii_lowercase
        elif count == 3:
            k_iter = ascii_lowercase

    while regex.find("[A-Z]") != -1:
        regex = regex.replace("[A-Z]", rep_var[count], 1)
        count += 1
        if count == 1:
            i_iter = ascii_uppercase
        elif count == 2:
            j_iter = ascii_uppercase
        elif count == 3:
            k_iter = ascii_uppercase

    while regex.find("\d") != -1:
        regex = regex.replace("\d", rep_var[count], 1)
        count += 1
        if count == 1:
            i_iter = range(0, 10)
        elif count == 2:
            j_iter = range(0, 10)
        elif count == 3:
            k_iter = range(0, 10)

    while regex.find("\s") != -1:
        regex = regex.replace("\s", rep_var[count], 1)
        count += 1
        if count == 1:
            i_iter = whitespace
        elif count == 2:
            j_iter = whitespace
        elif count == 3:
            k_iter = whitespace

    print(regex)
    print(i_iter, j_iter, k_iter)

    for i in i_iter:
        for j in j_iter:
            for k in k_iter:
                with ZipFile('archive.zip') as zf:
                    try:
                        password = regex.format(i=i, j=j, k=k).encode()
                        zf.extractall("output", pwd=password)
                        return password
                    except:
                        pass
    return None

for i in range(0, 10000):
    # Crack the zip file
    password = solve_challenge()
    if not password:
        quit()

    # Remove the cracking artifacts
    shutil.rmtree("output")

    # Extract the contents to ./solved
    with ZipFile('archive.zip') as zf:
        zf.extractall("solved", pwd=password)

    # Move the files for the next level up and replace current level
    shutil.move("solved/archive.zip", "archive.zip")
    shutil.move("solved/hint.txt", "hint.txt")

    # If there are any remnants, we most likely hit the flag
    for dirpath, dirnames, files in os.walk('solved'):
        if files:
            quit()

    # If we didn't hit the flag, rm -rf ./solved
    shutil.rmtree("solved")

Wow! Great project. Keep up the good work