def test_encrypt_large_bytes_padding():
des = DES(b"PASSWORD")
expected = b"\x15\x14\x4f\x75\x8c\x83\xd0\x34" \
b"\xe6\x19\x4b\xe6\x51\x22\xe3\x91" \
b"\x68\x02\xa9\xd8\x6c\x04\x1f\x2d" \
b"\x95\x1d\xc7\x12\xe4\x7c\x79\x04"
actual = des.encrypt(b"abcdefghijklmnopqrstuvwxyz")
assert actual == expected
def test_encrypt_decrypt_multiple_keys():
# run random tests with random keys and data
for i in range(512):
des = DES(os.urandom(8))
data = os.urandom(16)
enc_data = des.encrypt(data)
dec_data = des.decrypt(enc_data)
assert enc_data != data
assert dec_data == data
def test_expand_56bit_key():
expected = b"\x01\x80\x80\x61\x40\x29\x19\x0E"
actual = DES.key56_to_key64(b"\x01\x02\x03\x04\x05\x06\x07")
assert actual == expected
expected = b"\x51\x20\x54\x6b\x34\xba\x3d\xa4"
actual = DES.key56_to_key64(b"PASSWOR")
assert actual == expected
expected = b"\x45\x01\x01\x01\x01\x01\x01\x01"
actual = DES.key56_to_key64(b"D\x00\x00\x00\x00\x00\x00")
assert actual == expected
def des(k, d): # type: (bytes, bytes) -> bytes
"""DES encryption.
Indicates the encryption of an 8-byte data item `d` with the 7-byte key `k` using the Data Encryption Standard
(DES) algorithm in Electronic Codebook (ECB) mode. The result is 8 bytes in length ([FIPS46-2]).
Args:
k: The 7-byte key to use in the DES cipher.
d: The 8-byte data block to encrypt.
Returns:
bytes: The encrypted data block.
"""
return DES(DES.key56_to_key64(k)).encrypt(d)
def test_decrypt_fail_invalid_size():
with pytest.raises(
ValueError,
match="DES decryption block must be a multiple of 8 bytes") as exc:
des = DES(b"PASSWORD")
des.decrypt(b"\x01\x02\x03\x04")
def test_decrypt():
des = DES(b"PASSWORD")
expected = b"abcdefgh"
actual = des.decrypt(b"\x15\x14\x4f\x75\x8c\x83\xd0\x34")
assert actual == expected
def test_encrypt_block():
with pytest.raises(
ValueError,
match="DES 7-byte key is not 7 bytes in length, actual: 1") as exc:
DES.key56_to_key64(b"\x00")
def test_des_invalid_key_size():
with pytest.raises(
ValueError,
match="DES encryption key should be 8 bytes in length") as exc:
DES(b"\x01\x02")