46 lines
1.4 KiB
Python
46 lines
1.4 KiB
Python
from Crypto.Util.number import bytes_to_long, long_to_bytes
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from Crypto.Cipher import AES
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from Crypto.Util.Padding import pad
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from secret import password, flag
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from hashlib import sha256
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NB_ITERATIONS = 10871177237854734092489348927
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e = 65538
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#Old N : N = 16725961734830292192130856503318846470372809633859943564170796604233648911148664645199314305393113642834320744397102098813353759076302959550707448148205851497665038807780166936471173111197092391395808381534728287101705
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N = 14968794114523720195251887716913440457986979987674770429103169854116498198112478103466085455257317270930523061714030307370028304505577267672733143013124254253285088080041831478700041394909740024011681885623055622400205
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def derive_key(password):
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start = bytes_to_long(password)
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#Making sure I am safe from offline bruteforce attack
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for i in range(NB_ITERATIONS):
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start = start ** e
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start %= N
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#We are never too cautious let's make it harder
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key = 1
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for i in range(NB_ITERATIONS):
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key = key ** e
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key %= N
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key *= start
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key %= N
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return sha256(long_to_bytes(key)).digest()
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assert(len(password) == 2)
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assert(password.decode().isprintable())
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key = derive_key(password)
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IV = b"random_and_safe!"
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cipher = AES.new(key, AES.MODE_CBC,IV)
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enc = cipher.encrypt(pad(flag,16))
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with open("flag.enc","wb") as output_file:
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output_file.write(enc)
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