block cipher decryption support
This is a squash of previous commits plus new ones. Ran into a pile of
conflicts during the rebase and decided this was an easier way to retain
a sane commit history
diff --git a/tests/primitives/test_block.py b/tests/primitives/test_block.py
index 9f5905b..4a67002 100644
--- a/tests/primitives/test_block.py
+++ b/tests/primitives/test_block.py
@@ -15,11 +15,9 @@
import binascii
-import pretend
import pytest
from cryptography.primitives.block import BlockCipher, ciphers, modes
-from cryptography.primitives.block.base import _Operation
class TestBlockCipher(object):
@@ -29,40 +27,42 @@
modes.CBC(binascii.unhexlify(b"0" * 32))
)
+ def test_creates_encryptor(self):
+ cipher = BlockCipher(
+ ciphers.AES(binascii.unhexlify(b"0" * 32)),
+ modes.CBC(binascii.unhexlify(b"0" * 32))
+ )
+ assert cipher.encryptor() is not None
+
+ def test_creates_decryptor(self):
+ cipher = BlockCipher(
+ ciphers.AES(binascii.unhexlify(b"0" * 32)),
+ modes.CBC(binascii.unhexlify(b"0" * 32))
+ )
+ assert cipher.decryptor() is not None
+
+
+class TestBlockCipherContext(object):
def test_use_after_finalize(self, api):
cipher = BlockCipher(
ciphers.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32)),
api
)
- cipher.encrypt(b"a" * 16)
- cipher.finalize()
+ context = cipher.encryptor()
+ context.update(b"a" * 16)
+ context.finalize()
with pytest.raises(ValueError):
- cipher.encrypt(b"b" * 16)
+ context.update(b"b" * 16)
with pytest.raises(ValueError):
- cipher.finalize()
-
- def test_encrypt_with_invalid_operation(self, api):
- cipher = BlockCipher(
- ciphers.AES(binascii.unhexlify(b"0" * 32)),
- modes.CBC(binascii.unhexlify(b"0" * 32)),
- api
- )
- cipher._operation = _Operation.decrypt
-
+ context.finalize()
+ context = cipher.decryptor()
+ context.update(b"a" * 16)
+ context.finalize()
with pytest.raises(ValueError):
- cipher.encrypt(b"b" * 16)
-
- def test_finalize_with_invalid_operation(self, api):
- cipher = BlockCipher(
- ciphers.AES(binascii.unhexlify(b"0" * 32)),
- modes.CBC(binascii.unhexlify(b"0" * 32)),
- api
- )
- cipher._operation = pretend.stub(name="wat")
-
+ context.update(b"b" * 16)
with pytest.raises(ValueError):
- cipher.finalize()
+ context.finalize()
def test_unaligned_block_encryption(self, api):
cipher = BlockCipher(
@@ -70,7 +70,15 @@
modes.ECB(),
api
)
- ct = cipher.encrypt(b"a" * 15)
+ context = cipher.encryptor()
+ ct = context.update(b"a" * 15)
assert ct == b""
- ct += cipher.encrypt(b"a" * 65)
+ ct += context.update(b"a" * 65)
assert len(ct) == 80
+ ct += context.finalize()
+ context = cipher.decryptor()
+ pt = context.update(ct[:3])
+ assert pt == b""
+ pt += context.update(ct[3:])
+ assert len(pt) == 80
+ context.finalize()