def test_bad_key(self):
""" Raw AES requires keys of an exact size. """
with self.assertRaises(AssertionError):
AES(b'short key')
with self.assertRaises(AssertionError):
AES(b'long key' * 10)
def test_expected_values256(self):
message = b'\x00\x11\x22\x33\x44\x55\x66\x77\x88\x99\xAA\xBB\xCC\xDD\xEE\xFF'
aes = AES(
b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f'
)
ciphertext = aes.encrypt_block(message)
self.assertEqual(
ciphertext,
b'\x8e\xa2\xb7\xca\x51\x67\x45\xbf\xea\xfc\x49\x90\x4b\x49\x60\x89'
)
self.assertEqual(aes.decrypt_block(ciphertext), message)
def test_expected_values192(self):
message = b'\x00\x11\x22\x33\x44\x55\x66\x77\x88\x99\xAA\xBB\xCC\xDD\xEE\xFF'
aes = AES(
b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17'
)
ciphertext = aes.encrypt_block(message)
self.assertEqual(
ciphertext,
b'\xdd\xa9\x7c\xa4\x86\x4c\xdf\xe0\x6e\xaf\x70\xa0\xec\x0d\x71\x91'
)
self.assertEqual(aes.decrypt_block(ciphertext), message)
def test_expected_value(self):
"""
Tests taken from the NIST document, Appendix B:
http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
"""
message = b'\x32\x43\xF6\xA8\x88\x5A\x30\x8D\x31\x31\x98\xA2\xE0\x37\x07\x34'
key = b'\x2B\x7E\x15\x16\x28\xAE\xD2\xA6\xAB\xF7\x15\x88\x09\xCF\x4F\x3C'
ciphertext = AES(bytes(key)).encrypt_block(bytes(message))
self.assertEqual(
ciphertext,
b'\x39\x25\x84\x1D\x02\xDC\x09\xFB\xDC\x11\x85\x97\x19\x6A\x0B\x32'
)
class TestBlock(unittest.TestCase):
"""
Tests raw AES-128 block operations.
"""
def setUp(self):
self.aes = AES(b'\x00' * 16)
def test_success(self):
""" Should be able to encrypt and decrypt block messages. """
message = b'\x01' * 16
ciphertext = self.aes.encrypt_block(message)
self.assertEqual(self.aes.decrypt_block(ciphertext), message)
message = b'a secret message'
ciphertext = self.aes.encrypt_block(message)
self.assertEqual(self.aes.decrypt_block(ciphertext), message)
def test_bad_key(self):
""" Raw AES requires keys of an exact size. """
with self.assertRaises(AssertionError):
AES(b'short key')
with self.assertRaises(AssertionError):
AES(b'long key' * 10)
def test_expected_value(self):
"""
Tests taken from the NIST document, Appendix B:
http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
"""
message = b'\x32\x43\xF6\xA8\x88\x5A\x30\x8D\x31\x31\x98\xA2\xE0\x37\x07\x34'
key = b'\x2B\x7E\x15\x16\x28\xAE\xD2\xA6\xAB\xF7\x15\x88\x09\xCF\x4F\x3C'
ciphertext = AES(bytes(key)).encrypt_block(bytes(message))
self.assertEqual(
ciphertext,
b'\x39\x25\x84\x1D\x02\xDC\x09\xFB\xDC\x11\x85\x97\x19\x6A\x0B\x32'
)
def setUp(self):
self.aes = AES(b'\x00' * 16)
self.iv = b'\x01' * 16
self.message = b'my message'
class TestCbc(unittest.TestCase):
"""
Tests AES-128 in CBC mode.
"""
def setUp(self):
self.aes = AES(b'\x00' * 16)
self.iv = b'\x01' * 16
self.message = b'my message'
def test_single_block(self):
""" Should be able to encrypt and decrypt single block messages. """
ciphertext = self.aes.encrypt_cbc(self.message, self.iv)
self.assertEqual(self.aes.decrypt_cbc(ciphertext, self.iv),
self.message)
# Since len(message) < block size, padding won't create a new block.
self.assertEqual(len(ciphertext), 16)
def test_wrong_iv(self):
""" CBC mode should verify the IVs are of correct length."""
with self.assertRaises(AssertionError):
self.aes.encrypt_cbc(self.message, b'short iv')
with self.assertRaises(AssertionError):
self.aes.encrypt_cbc(self.message, b'long iv' * 16)
with self.assertRaises(AssertionError):
self.aes.decrypt_cbc(self.message, b'short iv')
with self.assertRaises(AssertionError):
self.aes.decrypt_cbc(self.message, b'long iv' * 16)
def test_different_iv(self):
""" Different IVs should generate different ciphertexts. """
iv2 = b'\x02' * 16
ciphertext1 = self.aes.encrypt_cbc(self.message, self.iv)
ciphertext2 = self.aes.encrypt_cbc(self.message, iv2)
self.assertNotEqual(ciphertext1, ciphertext2)
plaintext1 = self.aes.decrypt_cbc(ciphertext1, self.iv)
plaintext2 = self.aes.decrypt_cbc(ciphertext2, iv2)
self.assertEqual(plaintext1, plaintext2)
self.assertEqual(plaintext1, self.message)
def test_whole_block_padding(self):
""" When len(message) == block size, padding will add a block. """
block_message = b'M' * 16
ciphertext = self.aes.encrypt_cbc(block_message, self.iv)
self.assertEqual(len(ciphertext), 32)
self.assertEqual(self.aes.decrypt_cbc(ciphertext, self.iv),
block_message)
def test_long_message(self):
""" CBC should allow for messages longer than a single block. """
long_message = b'M' * 100
ciphertext = self.aes.encrypt_cbc(long_message, self.iv)
self.assertEqual(self.aes.decrypt_cbc(ciphertext, self.iv),
long_message)
def setUp(self):
self.aes = AES(b'\x00' * 16)
def test_256(self):
aes = AES(b'P' * 32)
message = b'M' * 16
ciphertext = aes.encrypt_block(message)
self.assertEqual(aes.decrypt_block(ciphertext), message)
class TestCtr(unittest.TestCase):
"""
Tests AES-128 in CBC mode.
"""
def setUp(self):
self.aes = AES(b'\x00' * 16)
self.iv = b'\x01' * 16
self.message = b'my message'
def test_single_block(self):
""" Should be able to encrypt and decrypt single block messages. """
ciphertext = self.aes.encrypt_ctr(self.message, self.iv)
self.assertEqual(self.aes.decrypt_ctr(ciphertext, self.iv),
self.message)
# Stream mode ciphers don't increase message size.
self.assertEqual(len(ciphertext), len(self.message))
def test_wrong_iv(self):
""" CBC mode should verify the IVs are of correct length."""
with self.assertRaises(AssertionError):
self.aes.encrypt_ctr(self.message, b'short iv')
with self.assertRaises(AssertionError):
self.aes.encrypt_ctr(self.message, b'long iv' * 16)
with self.assertRaises(AssertionError):
self.aes.decrypt_ctr(self.message, b'short iv')
with self.assertRaises(AssertionError):
self.aes.decrypt_ctr(self.message, b'long iv' * 16)
def test_different_iv(self):
""" Different IVs should generate different ciphertexts. """
iv2 = b'\x02' * 16
ciphertext1 = self.aes.encrypt_ctr(self.message, self.iv)
ciphertext2 = self.aes.encrypt_ctr(self.message, iv2)
self.assertNotEqual(ciphertext1, ciphertext2)
plaintext1 = self.aes.decrypt_ctr(ciphertext1, self.iv)
plaintext2 = self.aes.decrypt_ctr(ciphertext2, iv2)
self.assertEqual(plaintext1, plaintext2)
self.assertEqual(plaintext1, self.message)
def test_whole_block_padding(self):
block_message = b'M' * 16
ciphertext = self.aes.encrypt_ctr(block_message, self.iv)
self.assertEqual(len(ciphertext), len(block_message))
self.assertEqual(self.aes.decrypt_ctr(ciphertext, self.iv),
block_message)
def test_long_message(self):
long_message = b'M' * 100
ciphertext = self.aes.encrypt_ctr(long_message, self.iv)
self.assertEqual(self.aes.decrypt_ctr(ciphertext, self.iv),
long_message)