diff options
| -rw-r--r-- | cryptography/hazmat/primitives/hmac.py | 10 | ||||
| -rw-r--r-- | docs/hazmat/primitives/hmac.rst | 4 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hmac.py | 19 |
3 files changed, 29 insertions, 4 deletions
diff --git a/cryptography/hazmat/primitives/hmac.py b/cryptography/hazmat/primitives/hmac.py index 76d658aa..18cf7f09 100644 --- a/cryptography/hazmat/primitives/hmac.py +++ b/cryptography/hazmat/primitives/hmac.py @@ -16,13 +16,21 @@ from __future__ import absolute_import, division, print_function import six from cryptography import utils -from cryptography.exceptions import AlreadyFinalized, InvalidSignature +from cryptography.exceptions import ( + AlreadyFinalized, InvalidSignature, UnsupportedInterface +) + +from cryptography.hazmat.backends.interfaces import HMACBackend from cryptography.hazmat.primitives import constant_time, interfaces @utils.register_interface(interfaces.HashContext) class HMAC(object): def __init__(self, key, algorithm, backend, ctx=None): + if not isinstance(backend, HMACBackend): + raise UnsupportedInterface( + "Backend object does not implement HMACBackend") + if not isinstance(algorithm, interfaces.HashAlgorithm): raise TypeError("Expected instance of interfaces.HashAlgorithm.") self.algorithm = algorithm diff --git a/docs/hazmat/primitives/hmac.rst b/docs/hazmat/primitives/hmac.rst index 6ca9e167..ce4e8803 100644 --- a/docs/hazmat/primitives/hmac.rst +++ b/docs/hazmat/primitives/hmac.rst @@ -56,6 +56,10 @@ of a message. :class:`~cryptography.hazmat.backends.interfaces.HMACBackend` provider. + :raises cryptography.exceptions.UnsupportedInterface: This is raised if the + provided ``backend`` does not implement + :class:`~cryptography.hazmat.backends.interfaces.HMACBackend` + .. method:: update(msg) :param bytes msg: The bytes to hash and authenticate. diff --git a/tests/hazmat/primitives/test_hmac.py b/tests/hazmat/primitives/test_hmac.py index 88bed52c..af177d7a 100644 --- a/tests/hazmat/primitives/test_hmac.py +++ b/tests/hazmat/primitives/test_hmac.py @@ -21,8 +21,11 @@ import six from cryptography import utils from cryptography.exceptions import ( - AlreadyFinalized, UnsupportedHash, InvalidSignature + AlreadyFinalized, UnsupportedHash, InvalidSignature, + UnsupportedInterface ) + +from cryptography.hazmat.backends.interfaces import HMACBackend from cryptography.hazmat.primitives import hashes, hmac, interfaces from .utils import generate_base_hmac_test @@ -52,8 +55,11 @@ class TestHMAC(object): h.update(six.u("\u00FC")) def test_copy_backend_object(self): - pretend_hmac = pretend.stub() - pretend_backend = pretend.stub(hmacs=pretend_hmac) + @utils.register_interface(HMACBackend) + class PretendBackend(object): + pass + + pretend_backend = PretendBackend() copied_ctx = pretend.stub() pretend_ctx = pretend.stub(copy=lambda: copied_ctx) h = hmac.HMAC(b"key", hashes.SHA1(), backend=pretend_backend, @@ -104,3 +110,10 @@ class TestHMAC(object): def test_unsupported_hash(self, backend): with pytest.raises(UnsupportedHash): hmac.HMAC(b"key", UnsupportedDummyHash(), backend) + + +def test_invalid_backend(): + pretend_backend = object() + + with pytest.raises(UnsupportedInterface): + hmac.HMAC(b"key", hashes.SHA1(), pretend_backend) |