Use an enum for determining BlockCipher operation
diff --git a/cryptography/primitives/block/base.py b/cryptography/primitives/block/base.py
index 207c83d..2018138 100644
--- a/cryptography/primitives/block/base.py
+++ b/cryptography/primitives/block/base.py
@@ -12,9 +12,16 @@
# limitations under the License.
# TODO: which binding is used should be an option somewhere
+from enum import Enum
+
from cryptography.bindings.openssl import api
+class _Operation(Enum):
+ encrypt = "encrypt"
+ decrypt = "decrypt"
+
+
class BlockCipher(object):
def __init__(self, cipher, mode):
super(BlockCipher, self).__init__()
@@ -34,10 +41,10 @@
raise ValueError("BlockCipher was already finalized")
if self._operation is None:
- self._operation = "encrypt"
- elif self._operation != "encrypt":
+ self._operation = _Operation.encrypt
+ elif self._operation is not _Operation.encrypt:
raise ValueError("BlockCipher cannot encrypt when the operation is"
- " set to %s" % self._operation)
+ " set to %s" % self._operation.name)
return api.update_encrypt_context(self._ctx, plaintext)
@@ -45,11 +52,11 @@
if self._ctx is None:
raise ValueError("BlockCipher was already finalized")
- if self._operation == "encrypt":
+ if self._operation is _Operation.encrypt:
result = api.finalize_encrypt_context(self._ctx)
else:
raise ValueError("BlockCipher cannot finalize the unknown "
- "operation %s" % self._operation)
+ "operation %s" % self._operation.name)
self._ctx = None
return result
diff --git a/setup.py b/setup.py
index c3b754f..8fd8a72 100644
--- a/setup.py
+++ b/setup.py
@@ -10,12 +10,19 @@
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
+import sys
from setuptools import setup
+install_requires = [
+ "cffi>=0.6",
+]
+
+if sys.version_info[:2] < (3, 4):
+ install_requires += ["enum34"]
setup(
name="cryptography",
license="Apache License, Version 2.0",
- install_requires=["cffi>=0.6"],
+ install_requires=install_requires,
)
diff --git a/tests/primitives/test_block.py b/tests/primitives/test_block.py
index 799e5f0..9059a88 100644
--- a/tests/primitives/test_block.py
+++ b/tests/primitives/test_block.py
@@ -13,9 +13,11 @@
import binascii
+import pretend
import pytest
from cryptography.primitives.block import BlockCipher, ciphers, modes
+from cryptography.primitives.block.base import _Operation
class TestBlockCipher(object):
@@ -43,7 +45,7 @@
ciphers.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32))
)
- cipher._operation = "decrypt"
+ cipher._operation = _Operation.decrypt
with pytest.raises(ValueError):
cipher.encrypt(b"b" * 16)
@@ -53,7 +55,7 @@
ciphers.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32))
)
- cipher._operation = "wat"
+ cipher._operation = pretend.stub(name="wat")
with pytest.raises(ValueError):
cipher.encrypt(b"b" * 16)
diff --git a/tox.ini b/tox.ini
index 81c6675..80e0a15 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,7 +2,7 @@
envlist = py26,py27,pypy,py32,py33,docs,pep8
[testenv]
-deps = pytest-cov
+deps = pytest-cov pretend
commands = py.test --cov=cryptography/ --cov=tests/
[testenv:docs]