md5截断比较(python3)版本

# -*- coding: utf-8 -*-

import multiprocessing
import hashlib
import random
import string
import sys


CHARS = string.ascii_letters + string.digits


def cmp_md5(substr, stop_event, str_len, start=0, size=20):
    global CHARS

    while not stop_event.is_set():
        rnds = ''.join(random.choice(CHARS) for _ in range(size))
        md5 = hashlib.md5()
        md5.update(rnds.encode("utf8"))

        if md5.hexdigest()[start: start+str_len] == substr:
            print (rnds)
            stop_event.set()


if __name__ == '__main__':
    substr = sys.argv[1].strip()

    start_pos = int(sys.argv[2]) if len(sys.argv) > 1 else 0

    str_len = len(substr)
    cpus = multiprocessing.cpu_count()
    stop_event = multiprocessing.Event()
    processes = [multiprocessing.Process(target=cmp_md5, args=(substr,stop_event, str_len, start_pos))
                 for i in range(cpus)]

    for p in processes:
        p.start()

    for p in processes:
        p.join()

参考：

http://www.beesfun.com/2017/03/21/%E3%80%90CTF%E3%80%91MD5%E6%88%AA%E6%96%AD%E6%AF%94%E8%BE%83/