62 lines
1.5 KiB
Python
Executable File
62 lines
1.5 KiB
Python
Executable File
#!python3
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import random
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import string
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import hashlib
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import time
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from Crypto.Util.number import inverse, getPrime, bytes_to_long, GCD
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from sympy.ntheory.modular import solve_congruence
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FLAG = open('flag.txt', 'r').read()
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def CRT(a, m, b, n):
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val, mod = solve_congruence((a, m), (b, n))
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return val
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def gen_key():
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while True:
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p = getPrime(512)
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q = getPrime(512)
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if GCD(p-1, q-1) == 2:
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return p, q
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def get_clue(p, q, BITS):
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while True:
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d_p = random.randint(1, 1 << BITS)
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d_q = random.randint(1, q - 1)
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if d_p % 2 == d_q % 2:
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d = CRT(d_p, p - 1, d_q, q - 1)
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e = inverse(d, (p - 1) * (q - 1))
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print("Clue : ", e)
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return
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def get_flag(p, q):
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start = time.time()
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ans = int(input())
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if (time.time() - start) > (15 * 60):
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print("Too long!")
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exit()
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else:
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if ans == p + q:
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print(FLAG)
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else:
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print("oops...")
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#PoW
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vals1 = "".join([random.choice(string.digits) for _ in range(5)])
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vals2 = "".join([random.choice(string.hexdigits.lower()) for _ in range(6)])
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vals1 = "63494"
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vals2 = "c8ecb7"
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user_input = input("Enter a string that starts with \"{}\" (no quotes) which creates an md5 hash that ends in these six hex digits: {}\n".format(vals1, vals2))
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user_hash = hashlib.md5(user_input.encode()).hexdigest()
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if user_input[:5] == vals1 and user_hash[-6:] == vals2:
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p, q = gen_key()
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n = p * q
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print("Public Modulus : ", n)
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get_clue(p, q, 20)
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get_flag(p, q)
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