#!/usr/bin/env python3

import sys, hashlib

def decrypt_password(user, pass_enc):
    key = hashlib.md5(user + b"283i4jfkai3389").digest()

    passw = ""
    for i in range(0, len(pass_enc)):
        passw += chr(pass_enc[i] ^ key[i % len(key)])
    
    return passw.split("\x00")[0]

def extract_user_pass_from_entry(entry):
    user_data = entry.split(b"\x01\x00\x00\x21")[1]
    pass_data = entry.split(b"\x11\x00\x00\x21")[1]

    user_len = user_data[0]
    pass_len = pass_data[0]

    username = user_data[1:1 + user_len]
    password = pass_data[1:1 + pass_len]

    return username, password

def get_pair(data):

    user_list = []

    entries = data.split(b"M2")[1:]
    for entry in entries:
        try:
            user, pass_encrypted = extract_user_pass_from_entry(entry)
        except:
            continue

        pass_plain = decrypt_password(user, pass_encrypted)
        user = user.decode("utf_8", "backslashreplace")

        user_list.append((user, pass_plain))

    return user_list

def dump(data):
    user_pass = get_pair(data)
    for u, p in user_pass:
        print("User:", u)
        print("Pass:", p)
        print()

if __name__ == "__main__":
    if len(sys.argv) == 2:
        if sys.argv[1] == "-":
            user_file = sys.stdin.buffer.read()
        else:
            user_file = open(sys.argv[1], "rb").read()
        dump(user_file)
         
    else:
        print("Usage:")
        print("\tFrom file: \t", sys.argv[0], "user.dat")
        print("\tFrom stdin:\t", sys.argv[0], "-")