cvv.py

import random

visaPrefix = ["4539", "4556", "4916", "4532", "4929", "40240071", "4485", "4716", "4"]
mcPrefix = ["51", "52", "53", "54", "55"]
amexPrefix = ["34", "37"]
disPrefix = ["6011"]
dinnerPrefix = ["300", "301", "302", "303", "36", "38"]

def get_last_digit(ccn):
    length = len(ccn) + 1
    _sum = 0
    pos = 0
    r_ccn = []
    r_ccn.extend(ccn)
    r_ccn.reverse()
    while pos < length - 1:
        odd = int(r_ccn[pos]) * 2
        if odd > 9:
            odd -= 9
        _sum += odd
        if pos != (length - 2):
            _sum += int(r_ccn[pos + 1])
        pos += 2
    return str(((_sum / 10 + 1) * 10 - _sum) % 10)

def gen_card(_type):
    if _type == "visa":
        ccn = random.choice(visaPrefix)
    elif _type == "master":
        ccn = random.choice(mcPrefix)
    elif _type == "dis":
        ccn = random.choice(disPrefix)
    elif _type == "amex":
        ccn = random.choice(amexPrefix)
    elif _type == "dinner":
        ccn = random.choice(dinnerPrefix)
    else:
        ccn = _type
    if ccn.startswith("4"):
        length = 16
    elif ccn.startswith("30") or ccn.startswith("36") or ccn.startswith("38"):
        length = 14
    elif ccn.startswith("34") or ccn.startswith("37"):
        length = 15
    elif ccn.startswith("5") or ccn.startswith("6011"):
        length = 16
    else:
        length = 16
    while len(ccn) < (length - 1):
        digit = str(random.choice(range(0, 10)))
        ccn += digit

    ccn += get_last_digit(ccn)
    return ccn

import socket
import re

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("misc.chal.csaw.io", 8308))
while 1:
    need = s.recv(1024)
    print need
    if "MasterCard" in need:
        answer = gen_card("master")
    elif "Visa" in need:
        answer = gen_card("visa")
    elif "American" in need:
        answer = gen_card("amex")
    elif "Discover"  in need:
        answer = gen_card("dis")
    elif "starts with" in need:
        answer = gen_card(re.findall("\d+", need)[0])
    elif "ends with" in need:
        answer = ""
        while not answer.endswith(re.findall("\d+", need)[0]):
            answer = gen_card(random.choice(["3", "4", "5", "6"]))
    elif "Yes" in need:
        ccn = re.findall("\d{10,}", need)[0]
        if len(ccn) != 16:  answer = "0"
        elif get_last_digit(ccn[:-1]) == ccn[-1]: answer = "1"
        else: answer = "0"
    else:
        print "hmmmm"
        break
    print "Sending %s" %answer
    s.send(answer + "\n")