diff options
| -rw-r--r-- | cryptography/hazmat/backends/interfaces.py | 7 | ||||
| -rw-r--r-- | cryptography/hazmat/backends/openssl/backend.py | 3 | ||||
| -rw-r--r-- | docs/hazmat/backends/interfaces.rst | 11 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hmac.py | 2 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hmac_vectors.py | 14 |
5 files changed, 29 insertions, 8 deletions
diff --git a/cryptography/hazmat/backends/interfaces.py b/cryptography/hazmat/backends/interfaces.py index 912476bb..9a570968 100644 --- a/cryptography/hazmat/backends/interfaces.py +++ b/cryptography/hazmat/backends/interfaces.py @@ -60,6 +60,13 @@ class HashBackend(six.with_metaclass(abc.ABCMeta)): class HMACBackend(six.with_metaclass(abc.ABCMeta)): @abc.abstractmethod + def hmac_supported(self, algorithm): + """ + Return True if the hash algorithm is supported for HMAC by this + backend. + """ + + @abc.abstractmethod def create_hmac_ctx(self, key, algorithm): """ Create a HashContext for calculating a message authentication code. diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index f11ddf22..7b67fb0b 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -184,6 +184,9 @@ class Backend(object): digest = self.lib.EVP_get_digestbyname(algorithm.name.encode("ascii")) return digest != self.ffi.NULL + def hmac_supported(self, algorithm): + return self.hash_supported(algorithm) + def create_hash_ctx(self, algorithm): return _HashContext(self, algorithm) diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst index b524943d..5b6cd64d 100644 --- a/docs/hazmat/backends/interfaces.rst +++ b/docs/hazmat/backends/interfaces.rst @@ -126,6 +126,17 @@ A specific ``backend`` may provide one or more of these interfaces. A backend with methods for using cryptographic hash functions as message authentication codes. + .. method:: hmac_supported(algorithm) + + Check if the specified ``algorithm`` is supported by this backend. + + :param algorithm: An instance of a + :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm` + provider. + + :returns: ``True`` if the specified ``algorithm`` is supported for HMAC + by this backend, otherwise ``False``. + .. method:: create_hmac_ctx(algorithm) Create a diff --git a/tests/hazmat/primitives/test_hmac.py b/tests/hazmat/primitives/test_hmac.py index 124c4377..1e776c98 100644 --- a/tests/hazmat/primitives/test_hmac.py +++ b/tests/hazmat/primitives/test_hmac.py @@ -34,7 +34,7 @@ class UnsupportedDummyHash(object): class TestHMAC(object): test_copy = generate_base_hmac_test( hashes.MD5(), - only_if=lambda backend: backend.hash_supported(hashes.MD5), + only_if=lambda backend: backend.hmac_supported(hashes.MD5), skip_message="Does not support MD5", ) diff --git a/tests/hazmat/primitives/test_hmac_vectors.py b/tests/hazmat/primitives/test_hmac_vectors.py index 7d0f156a..f884d850 100644 --- a/tests/hazmat/primitives/test_hmac_vectors.py +++ b/tests/hazmat/primitives/test_hmac_vectors.py @@ -27,7 +27,7 @@ class TestHMAC_MD5(object): "rfc-2202-md5.txt", ], hashes.MD5(), - only_if=lambda backend: backend.hash_supported(hashes.MD5), + only_if=lambda backend: backend.hmac_supported(hashes.MD5), skip_message="Does not support MD5", ) @@ -40,7 +40,7 @@ class TestHMAC_SHA1(object): "rfc-2202-sha1.txt", ], hashes.SHA1(), - only_if=lambda backend: backend.hash_supported(hashes.SHA1), + only_if=lambda backend: backend.hmac_supported(hashes.SHA1), skip_message="Does not support SHA1", ) @@ -53,7 +53,7 @@ class TestHMAC_SHA224(object): "rfc-4231-sha224.txt", ], hashes.SHA224(), - only_if=lambda backend: backend.hash_supported(hashes.SHA224), + only_if=lambda backend: backend.hmac_supported(hashes.SHA224), skip_message="Does not support SHA224", ) @@ -66,7 +66,7 @@ class TestHMAC_SHA256(object): "rfc-4231-sha256.txt", ], hashes.SHA256(), - only_if=lambda backend: backend.hash_supported(hashes.SHA256), + only_if=lambda backend: backend.hmac_supported(hashes.SHA256), skip_message="Does not support SHA256", ) @@ -79,7 +79,7 @@ class TestHMAC_SHA384(object): "rfc-4231-sha384.txt", ], hashes.SHA384(), - only_if=lambda backend: backend.hash_supported(hashes.SHA384), + only_if=lambda backend: backend.hmac_supported(hashes.SHA384), skip_message="Does not support SHA384", ) @@ -92,7 +92,7 @@ class TestHMAC_SHA512(object): "rfc-4231-sha512.txt", ], hashes.SHA512(), - only_if=lambda backend: backend.hash_supported(hashes.SHA512), + only_if=lambda backend: backend.hmac_supported(hashes.SHA512), skip_message="Does not support SHA512", ) @@ -105,6 +105,6 @@ class TestHMAC_RIPEMD160(object): "rfc-2286-ripemd160.txt", ], hashes.RIPEMD160(), - only_if=lambda backend: backend.hash_supported(hashes.RIPEMD160), + only_if=lambda backend: backend.hmac_supported(hashes.RIPEMD160), skip_message="Does not support RIPEMD160", ) |