diff options
| -rw-r--r-- | cryptography/hazmat/primitives/hashes.py | 7 | ||||
| -rw-r--r-- | docs/hazmat/primitives/cryptographic-hashes.rst | 4 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hashes.py | 18 |
3 files changed, 26 insertions, 3 deletions
diff --git a/cryptography/hazmat/primitives/hashes.py b/cryptography/hazmat/primitives/hashes.py index bee188b3..409f564e 100644 --- a/cryptography/hazmat/primitives/hashes.py +++ b/cryptography/hazmat/primitives/hashes.py @@ -16,13 +16,18 @@ from __future__ import absolute_import, division, print_function import six from cryptography import utils -from cryptography.exceptions import AlreadyFinalized +from cryptography.exceptions import AlreadyFinalized, UnsupportedInterface +from cryptography.hazmat.backends.interfaces import HashBackend from cryptography.hazmat.primitives import interfaces @utils.register_interface(interfaces.HashContext) class Hash(object): def __init__(self, algorithm, backend, ctx=None): + if not isinstance(backend, HashBackend): + raise UnsupportedInterface( + "Backend object does not implement HashBackend") + if not isinstance(algorithm, interfaces.HashAlgorithm): raise TypeError("Expected instance of interfaces.HashAlgorithm.") self.algorithm = algorithm diff --git a/docs/hazmat/primitives/cryptographic-hashes.rst b/docs/hazmat/primitives/cryptographic-hashes.rst index 627ca7bd..b7eee2f5 100644 --- a/docs/hazmat/primitives/cryptographic-hashes.rst +++ b/docs/hazmat/primitives/cryptographic-hashes.rst @@ -45,6 +45,10 @@ Message Digests :class:`~cryptography.hazmat.backends.interfaces.HashBackend` provider. + :raises cryptography.exceptions.UnsupportedInterface: This is raised if the + provided ``backend`` does not implement + :class:`~cryptography.hazmat.backends.interfaces.HashBackend` + .. method:: update(data) :param bytes data: The bytes to be hashed. diff --git a/tests/hazmat/primitives/test_hashes.py b/tests/hazmat/primitives/test_hashes.py index fc53d635..a7af8a8d 100644 --- a/tests/hazmat/primitives/test_hashes.py +++ b/tests/hazmat/primitives/test_hashes.py @@ -20,7 +20,10 @@ import pytest import six from cryptography import utils -from cryptography.exceptions import AlreadyFinalized, UnsupportedHash +from cryptography.exceptions import ( + AlreadyFinalized, UnsupportedHash, UnsupportedInterface) + +from cryptography.hazmat.backends.interfaces import HashBackend from cryptography.hazmat.primitives import hashes, interfaces from .utils import generate_base_hash_test @@ -39,7 +42,11 @@ class TestHashContext(object): m.update(six.u("\u00FC")) def test_copy_backend_object(self): - pretend_backend = pretend.stub() + @utils.register_interface(HashBackend) + class PretendBackend(object): + pass + + pretend_backend = PretendBackend() copied_ctx = pretend.stub() pretend_ctx = pretend.stub(copy=lambda: copied_ctx) h = hashes.Hash(hashes.SHA1(), backend=pretend_backend, @@ -171,3 +178,10 @@ class TestMD5(object): digest_size=16, block_size=64, ) + + +def test_invalid_backend(): + pretend_backend = object() + + with pytest.raises(UnsupportedInterface): + hashes.Hash(hashes.SHA1(), pretend_backend) |