def test_ctr256_decrypt(self):
key = bytes.fromhex("""
603DEB10 15CA71BE 2B73AEF0 857D7781
1F352C07 3B6108D7 2D9810A3 0914DFF4
""".replace(" ", "").replace("\n", ""))
iv = bytes.fromhex("""
F0F1F2F3 F4F5F6F7 F8F9FAFB FCFDFEFF
""".replace(" ", "").replace("\n", ""))
ciphertext = bytes.fromhex("""
601EC313 775789A5 B7A7F504 BBF3D228
F443E3CA 4D62B59A CA84E990 CACAF5C5
2B0930DA A23DE94C E87017BA 2D84988D
DFC9C58D B67AADA6 13C2DD08 457941A6
""".replace(" ", "").replace("\n", ""))
plaintext = bytes.fromhex("""
6BC1BEE2 2E409F96 E93D7E11 7393172A
AE2D8A57 1E03AC9C 9EB76FAC 45AF8E51
30C81C46 A35CE411 E5FBC119 1A0A52EF
F69F2445 DF4F9B17 AD2B417B E66C3710
""".replace(" ", "").replace("\n", ""))
self.assertEqual(
tgcrypto.ctr256_decrypt(ciphertext, key, iv, bytes(1)), plaintext)
def decrypt(self, data):
"""
Decrypts the given cipher text through AES CTR
:param data: the cipher text to be decrypted.
:return: the decrypted plain text.
"""
if tgcrypto:
return tgcrypto.ctr256_decrypt(data, *self._aes)
return self._aes.decrypt(data)
def ctr256_decrypt(data: bytes,
key: bytes,
iv: bytearray,
state: bytearray = None) -> bytes:
return tgcrypto.ctr256_decrypt(data, key, iv, state
or bytearray(1))
def test_ctr256_decrypt_invalid_state_value(self):
with self.assertRaisesRegex(
ValueError, r"State value must be in the range \[0, 15\]"):
tgcrypto.ctr256_decrypt(os.urandom(8), os.urandom(32),
os.urandom(16), bytes([16]))
def test_ctr256_decrypt_invalid_state_size(self):
with self.assertRaisesRegex(ValueError,
r"State size must be exactly 1 byte"):
tgcrypto.ctr256_decrypt(os.urandom(8), os.urandom(32),
os.urandom(16), bytes([1, 2, 3]))
def test_ctr256_decrypt_invalid_iv_size(self):
with self.assertRaisesRegex(ValueError,
r"IV size must be exactly 16 bytes"):
tgcrypto.ctr256_decrypt(os.urandom(8), os.urandom(32),
os.urandom(15), bytes(1))
def test_ctr256_decrypt_invalid_key_size(self):
with self.assertRaisesRegex(ValueError,
r"Key size must be exactly 32 bytes"):
tgcrypto.ctr256_decrypt(os.urandom(8), os.urandom(31),
os.urandom(16), bytes(1))
def test_ctr256_decrypt_empty_data(self):
with self.assertRaisesRegex(ValueError, r"Data must not be empty"):
tgcrypto.ctr256_decrypt(b"", os.urandom(32), os.urandom(16),
bytes(1))
def test_ctr256_decrypt_invalid_args_type(self):
with self.assertRaisesRegex(TypeError, self.TYPE_ERROR_PATTERN):
tgcrypto.ctr256_decrypt(1, 2, 3, 4)
def test_ctr256_decrypt_invalid_args_count(self):
with self.assertRaisesRegex(
TypeError,
r"function takes exactly \d arguments \(\d given\)"):
tgcrypto.ctr256_decrypt(os.urandom(8), os.urandom(32),
os.urandom(16))
def decrypt(self, data):
return tgcrypto.ctr256_decrypt(data, self.key, self.iv, bytes(1))
