def test_cbc_custom_decrypt(self):
k = b'\x81\x0ff\t\x04\xb6\xcf\x1f.\x10\x8frd\xb4E\x19'
cipher = b'e|\x92\xd0\x8b\xd9\x00\xc8X\xf2Noi\xa1\x155\x8b\xa5\xb7\xdcka\xaa\x94=a_!x\x1a\xcf\xf4'
n = 1
assert len(cipher) == 32
iv = b'e|\x92\xd0\x8b\xd9\x00\xc8X\xf2Noi\xa1\x155'
cipher_text = AES.new(k, AES.MODE_CBC, iv)
assert cipher_text.decrypt(cipher[16:]) == cbc_custom_decrypt(
k, n, cipher)
k = b'\x81\x0ff\t\x04\xb6\xcf\x1f.\x10\x8frd\xb4E\x19'
iv = b'9193470938756473'
cipher = iv + b'93746483900993873765345729285341'
n = 2
assert len(cipher) == 48
cipher_text = AES.new(k, AES.MODE_CBC, iv)
assert cipher_text.decrypt(cipher[16:]) == cbc_custom_decrypt(
k, n, cipher)
k = b'3939378487348557'
iv = b'8870123765252522'
cipher = iv + b'937464839009938737653457292853411010109394847645'
n = 3
assert len(cipher) == 64
cipher_text = AES.new(k, AES.MODE_CBC, iv)
assert cipher_text.decrypt(cipher[16:]) == cbc_custom_decrypt(
k, n, cipher)
def test_cbc_custom_decrypt(num_tests=1000):
from Crypto.Random import get_random_bytes
# we'll use AES CBC
key = get_random_bytes(block_size)
aes = AES.new(key, AES.MODE_CBC, iv=get_random_bytes(block_size))
total_cipher = aes.iv
total_message = bytes([])
for i in range(num_tests):
# create a random message
message = get_random_bytes(block_size)
# concatenate the new ciphertext and mdessage to the whole strings
total_cipher += aes.encrypt(message)
total_message += message
decryption = cbc_custom_decrypt(key, i + 1, total_cipher)
if decryption != total_message:
# raise Exception("Failed a test")
print("Failed a test")
break
else:
print(f"Passed all cbc_custom_decrypt tests ({num_tests} random tests)")
def output_example_test():
# key = b'\x81\x0ff\t\x04\xb6\xcf\x1f.\x10\x8frd\xb4E\x19'
# key_hex = '810f660904b6cf1f2e108f7264b44519'
# iv = b'e|\x92\xd0\x8b\xd9\x00\xc8X\xf2Noi\xa1\x155'
# cipher = b'e|\x92\xd0\x8b\xd9\x00\xc8X\xf2Noi\xa1\x155\xb5b\xe7r\xb1\xec\xb5\xed\xca\xca\x1f$\xf8\xe33%'
# output = b'\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01'
key = b'\x81\x0ff\t\x04\xb6\xcf\x1f.\x10\x8frd\xb4E\x19'
cipher = b'e|\x92\xd0\x8b\xd9\x00\xc8X\xf2Noi\xa1\x155\xb5b\xe7r\xb1\xec\xb5\xed\xca\xca\x1f$\xf8\xe33%'
message = b'1111111111111111'
dec = cbc_custom_decrypt(key, 1, cipher)
if message == dec:
print("Passed example test")
else:
print("Failed example test")
def testing_decrypt(testsing_dict):
errors = 1
test_num = 1
for test in testsing_dict:
key, iv = test["key"], test["iv"]
for plain_text, c in zip(test["plain"], test["cipher"]):
num_of_blocks = len(c) // 16
my_output = cbc_custom_decrypt(key, num_of_blocks, iv + c)
if my_output != plain_text:
print("Error #{} in Test #{}".format(errors, test_num))
print("in: {}\n\tplain text should be: {}\n\tcipher is: {}\n".format(errors, my_output, plain_text, c))
errors += 1
else:
print("Passed Test #{}".format(test_num))
test_num += 1
if errors == 1:
print("Passed The Test: testing_decrypt")
else:
print("Didn't Pass The Test")