因為需要準備出差, 只做了一些小題
CVV
信用卡號碼算算號器和隨機生成器
https://zh.wikipedia.org/zh-hans/Luhn%E7%AE%97%E6%B3%95
從網(wǎng)上找的代碼，有問題按照Luhn代碼算法說明改
代碼很爛，都是粘的還有錯。。。
#!/usr/bin/env python
# author: garbu
from random import randint
from pwn import *
def generate_card(type):
"""
Prefill some values based on the card type
"""
card_types = ["americanexpress","visa11", "visa16","mastercard","discover"
def prefill(t):
# typical number of digits in credit card
def_length = 16
"""
Prefill with initial numbers and return it including the total number of digits
remaining to fill
"""
if 'num:' in t:
return [int(t[4]), int(t[5]), int(t[6]), int(t[7])], 12
if t == card_types[0]:
# american express starts with 3 and is 15 digits long
# override the def lengths
return [3, randint(4,7)], 13
elif t == card_types[1] or t == card_types[2]:
# visa starts with 4
if t.endswith("16"):
return [4], def_length - 1
else:
return [4], 10
elif t == card_types[3]:
# master card start with 5 and is 16 digits long
return [5, randint(1,5)], def_length - 2
elif t == card_types[4]:
# discover card starts with 6011 and is 16 digits long
return [6, 0, 1, 1], def_length - 4
else:
# this section probably not even needed here
return [], def_length
def finalize(nums):
"""
Make the current generated list pass the Luhn check by checking and adding
the last digit appropriately bia calculating the check sum
"""
check_sum = 0
#is_even = True if (len(nums) + 1 % 2) == 0 else False
"""
Reason for this check offset is to figure out whther the final list is going
to be even or odd which will affect calculating the check_sum.
This is mainly also to avoid reversing the list back and forth which is specified
on the Luhn algorithm.
"""
check_offset = (len(nums) + 1) % 2
for i, n in enumerate(nums):
if (i + check_offset) % 2 == 0:
n_ = n*2
check_sum += n_ -9 if n_ > 9 else n_
else:
check_sum += n
if check_sum % 10 == 0:
return nums + [0]
return nums + [10 - (check_sum % 10) ]
# main body
t = type.lower()
initial, rem = prefill(t)
so_far = initial + [randint(1,9) for x in xrange(rem - 1)]
#print "Card type: %s, " % t
cardnum = "".join(map(str,finalize(so_far))).strip('\n')
print cardnum
return cardnum
# # run - check
# generate_card("discover")
# generate_card("mastercard")
# generate_card("americanexpress")
# generate_card("visa13")
# generate_card("visa16")
def ck(nums):
"""
Make the current generated list pass the Luhn check by checking and adding
the last digit appropriately bia calculating the check sum
"""
check_sum = 0
is_even = True if ((len(nums) + 1 )% 2) == 0 else False
"""
Reason for this check offset is to figure out whther the final list is going
to be even or odd which will affect calculating the check_sum.
This is mainly also to avoid reversing the list back and forth which is specified
on the Luhn algorithm.
"""
check_offset = (len(nums) + 1) % 2
for i, n in enumerate(nums):
i = int(i)
n = int(n)
if i == 0:
if is_even:
n_ = n*2
check_sum += n_ -9 if n_ > 9 else n_
else:
check_sum += n
continue;
if (i + check_offset) % 2 == 0:
n_ = n*2
check_sum += n_ -9 if n_ > 9 else n_
else:
check_sum += n
if check_sum % 10 == 0:
return 0
return 10 - (check_sum % 10)
def ck2(nums):
digits = [int(i) for i in str(nums)]
odd_digits = digits[-1::-2]
even_digits = digits[-2::-2]
total = sum(odd_digits)
for digit in even_digits:
total += sum([int(i) for i in str(2 * digit)])
if total % 10 == 0:
return "1"
else:
return "0"
conn = remote("misc.chal.csaw.io", 8308)
while True:
cmd = conn.recvline()
print cmd,
if 'I need to know if ' in cmd:
card = "".join(filter(str.isdigit, cmd))
card = card[:-2]
print card
conn.sendline(ck2(card))
conn.recvline()
elif 'Visa' in cmd:
conn.sendline(generate_card('visa16'))
elif 'MasterCard' in cmd:
conn.sendline(generate_card('mastercard'))
elif 'Discover' in cmd:
conn.sendline(generate_card('discover'))
elif 'American Express' in cmd:
conn.sendline(generate_card('americanexpress'))
elif 'starts with' in cmd:
num = generate_card("num:" + cmd[-6:-2])
conn.sendline(num)
elif 'ends with' in cmd and cmd[-4] in '01234567890':
num = cmd[-6:-2]
while True:
card = generate_card('visa11') + '1' + num
if ck(card[:-1]) == int(card[-1]):
print card
conn.sendline(card)
break;
elif 'ends with' in cmd:
num = cmd[-3:-2]
while True:
card = generate_card('visa16')
if card[-1] == num:
conn.sendline(card)
break;
print conn.recvline(),
tabIEZ
Ascii值用表置換，長度不長直接手動查表逐位算出來的
tu.jpg
