def challenge34():
p = 197
g = 3
dh1 = DiffieHellman()
dh2 = DiffieHellman()
dh1._p = dh2._p = p
dh1._g = dh2._g = g
A = dh1.gen_pub()
B = dh2.gen_pub()
#dh2.gen_secret(A)
dh2.gen_secret(p)
#dh1.gen_secret(B)
dh1.gen_secret(p)
message = b'hello, MITM'
key1 = hashlib.sha1(dh1.secret.to_bytes(64, 'big')).digest()[:16]
iv1 = os.urandom(16)
ct1 = set2.aes_cbc_encrypt(message, key1, iv1)
key2 = hashlib.sha1(dh2.secret.to_bytes(64, 'big')).digest()[:16]
iv2 = os.urandom(16)
message2 = set2.aes_cbc_decrypt(ct1, key2, iv1)
ct2 = set2.aes_cbc_encrypt(message2, key2, iv2)
message3 = set2.aes_cbc_decrypt(ct2, key1, iv2)
assert message == message3
key3 = hashlib.sha1((0).to_bytes(64, 'big')).digest()[:16]
message4 = set2.aes_cbc_decrypt(ct1, key3, iv1)
assert message == message4
def challenge35():
p = 197
g = 3
dh1 = DiffieHellman()
dh2 = DiffieHellman()
for fg in [1, p, p - 1]:
dh1._p = dh2._p = p
dh1._g = dh2._g = fg
A = dh1.gen_pub()
B = dh2.gen_pub()
dh2.gen_secret(A)
dh1.gen_secret(B)
message = b'hello, MITM'
key1 = hashlib.sha1(dh1.secret.to_bytes(64, 'big')).digest()[:16]
iv1 = os.urandom(16)
ct1 = set2.aes_cbc_encrypt(message, key1, iv1)
key2 = hashlib.sha1(dh2.secret.to_bytes(64, 'big')).digest()[:16]
iv2 = os.urandom(16)
message2 = set2.aes_cbc_decrypt(ct1, key2, iv1)
ct2 = set2.aes_cbc_encrypt(message2, key2, iv2)
message3 = set2.aes_cbc_decrypt(ct2, key1, iv2)
assert message == message3
if fg == 1:
s = 1
elif fg == p:
s = 0
else:
if A == p - 1 and B == p - 1:
s = p - 1
else:
s = 1
key3 = hashlib.sha1((s).to_bytes(64, 'big')).digest()[:16]
message4 = set2.aes_cbc_decrypt(ct1, key3, iv1)
assert message == message4
def test_challenge33():
dh1 = DiffieHellman()
dh2 = DiffieHellman()
dh1._p = dh2._p = int(
'ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024'
'e088a67cc74020bbea63b139b22514a08798e3404ddef9519b3cd'
'3a431b302b0a6df25f14374fe1356d6d51c245e485b576625e7ec'
'6f44c42e9a637ed6b0bff5cb6f406b7edee386bfb5a899fa5ae9f'
'24117c4b1fe649286651ece45b3dc2007cb8a163bf0598da48361'
'c55d39a69163fa8fd24cf5f83655d23dca3ad961c62f356208552'
'bb9ed529077096966d670c354e4abc9804f1746c08ca237327fff'
'fffffffffffff', 16)
dh1._g = dh2._g = 2
pub1 = dh1.gen_pub()
pub2 = dh2.gen_pub()
dh1.gen_secret(pub2)
dh2.gen_secret(pub1)
assert dh1.secret == dh2.secret
