diff options
| -rw-r--r-- | .coveragerc | 1 | ||||
| -rw-r--r-- | cryptography/hazmat/primitives/hashes.py | 59 | ||||
| -rw-r--r-- | cryptography/hazmat/primitives/interfaces.py | 46 | ||||
| -rw-r--r-- | docs/hazmat/primitives/cryptographic-hashes.rst | 28 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hash_vectors.py | 20 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_hashes.py | 39 | ||||
| -rw-r--r-- | tests/hazmat/primitives/utils.py | 29 |
7 files changed, 139 insertions, 83 deletions
diff --git a/.coveragerc b/.coveragerc index b891cb7c..20e3224e 100644 --- a/.coveragerc +++ b/.coveragerc @@ -4,3 +4,4 @@ branch = True [report] exclude_lines = @abc.abstractmethod + @abc.abstractproperty diff --git a/cryptography/hazmat/primitives/hashes.py b/cryptography/hazmat/primitives/hashes.py index 3ccb59d1..bdad5e16 100644 --- a/cryptography/hazmat/primitives/hashes.py +++ b/cryptography/hazmat/primitives/hashes.py @@ -13,89 +13,94 @@ from __future__ import absolute_import, division, print_function -import abc +import six -import binascii +from cryptography.hazmat.primitives import interfaces -import six +@interfaces.register(interfaces.HashContext) +class Hash(object): + def __init__(self, algorithm, backend=None, ctx=None): + if not isinstance(algorithm, interfaces.HashAlgorithm): + raise TypeError("Expected instance of interfaces.HashAlgorithm.") + self.algorithm = algorithm -class BaseHash(six.with_metaclass(abc.ABCMeta)): - def __init__(self, data=None, backend=None, ctx=None): if backend is None: from cryptography.hazmat.bindings import _default_backend backend = _default_backend + self._backend = backend + if ctx is None: - self._ctx = self._backend.hashes.create_ctx(self) + self._ctx = self._backend.hashes.create_ctx(self.algorithm) else: self._ctx = None - if data is not None: - self.update(data) - def update(self, data): if isinstance(data, six.text_type): raise TypeError("Unicode-objects must be encoded before hashing") self._backend.hashes.update_ctx(self._ctx, data) def copy(self): - return self.__class__(backend=self._backend, ctx=self._copy_ctx()) - - def digest(self): - return self._backend.hashes.finalize_ctx(self._copy_ctx(), - self.digest_size) - - def hexdigest(self): - return str(binascii.hexlify(self.digest()).decode("ascii")) + return self.__class__(self.algorithm, backend=self._backend, + ctx=self._backend.hashes.copy_ctx(self._ctx)) - def _copy_ctx(self): - return self._backend.hashes.copy_ctx(self._ctx) + def finalize(self): + return self._backend.hashes.finalize_ctx(self._ctx, + self.algorithm.digest_size) -class SHA1(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class SHA1(object): name = "sha1" digest_size = 20 block_size = 64 -class SHA224(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class SHA224(object): name = "sha224" digest_size = 28 block_size = 64 -class SHA256(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class SHA256(object): name = "sha256" digest_size = 32 block_size = 64 -class SHA384(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class SHA384(object): name = "sha384" digest_size = 48 block_size = 128 -class SHA512(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class SHA512(object): name = "sha512" digest_size = 64 block_size = 128 -class RIPEMD160(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class RIPEMD160(object): name = "ripemd160" digest_size = 20 block_size = 64 -class Whirlpool(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class Whirlpool(object): name = "whirlpool" digest_size = 64 block_size = 64 -class MD5(BaseHash): +@interfaces.register(interfaces.HashAlgorithm) +class MD5(object): name = "md5" digest_size = 16 block_size = 64 diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py index 217490fd..ebf5e31e 100644 --- a/cryptography/hazmat/primitives/interfaces.py +++ b/cryptography/hazmat/primitives/interfaces.py @@ -59,3 +59,49 @@ class PaddingContext(six.with_metaclass(abc.ABCMeta)): """ finalize return bytes """ + + +class HashAlgorithm(six.with_metaclass(abc.ABCMeta)): + @abc.abstractproperty + def name(self): + """ + A string naming this algorithm. (ex. sha256, md5) + """ + + @abc.abstractproperty + def digest_size(self): + """ + The size of the resulting digest in bytes. + """ + + @abc.abstractproperty + def block_size(self): + """ + The internal block size of the hash algorithm in bytes. + """ + + +class HashContext(six.with_metaclass(abc.ABCMeta)): + @abc.abstractproperty + def algorithm(self): + """ + A HashAlgorithm that will be used by this context. + """ + + @abc.abstractmethod + def update(self, data): + """ + hash data as bytes + """ + + @abc.abstractmethod + def finalize(self): + """ + finalize this copy of the hash and return the digest as bytes. + """ + + @abc.abstractmethod + def copy(self): + """ + return a HashContext that is a copy of the current context. + """ diff --git a/docs/hazmat/primitives/cryptographic-hashes.rst b/docs/hazmat/primitives/cryptographic-hashes.rst index c780dcb0..a939998d 100644 --- a/docs/hazmat/primitives/cryptographic-hashes.rst +++ b/docs/hazmat/primitives/cryptographic-hashes.rst @@ -5,21 +5,27 @@ Message Digests .. currentmodule:: cryptography.hazmat.primitives.hashes -.. class:: BaseHash(data=None) +.. class:: Hash(algorithm) - Abstract base class that implements a common interface for all hash - algorithms that follow here. + A cryptographic hash function takes an arbitrary block of data and + calculates a fixed-size bit string (a digest), such that different data + results (with a high probability) in different digests. - If ``data`` is provided ``update(data)`` is called upon construction. + This is an implementation of + :class:`cryptography.hazmat.primitives.interfaces.HashContext` meant to + be used with + :class:`cryptography.hazmat.primitives.interfaces.HashAlgorithm` + implementations to provide an incremental interface to calculating + various message digests. .. doctest:: >>> from cryptography.hazmat.primitives import hashes - >>> digest = hashes.SHA256() + >>> digest = hashes.Hash(hashes.SHA256()) >>> digest.update(b"abc") >>> digest.update(b"123") - >>> digest.hexdigest() - '6ca13d52ca70c883e0f0bb101e425a89e8624de51db2d2392593af6a84118090' + >>> digest.finalize() + 'l\xa1=R\xcap\xc8\x83\xe0\xf0\xbb\x10\x1eBZ\x89\xe8bM\xe5\x1d\xb2\xd29%\x93\xafj\x84\x11\x80\x90' .. method:: update(data) @@ -29,13 +35,13 @@ Message Digests :return: a new instance of this object with a copied internal state. - .. method:: digest() + .. method:: finalize() + Finalize the current context and return the message digest as bytes. - :return bytes: The message digest as bytes. + Once ``finalize`` is called this object can no longer be used. - .. method:: hexdigest() + :return bytes: The message digest as bytes. - :return str: The message digest as hex. SHA-1 ~~~~~ diff --git a/tests/hazmat/primitives/test_hash_vectors.py b/tests/hazmat/primitives/test_hash_vectors.py index 5c3e72d4..fca839c7 100644 --- a/tests/hazmat/primitives/test_hash_vectors.py +++ b/tests/hazmat/primitives/test_hash_vectors.py @@ -29,7 +29,7 @@ class TestSHA1(object): "SHA1LongMsg.rsp", "SHA1ShortMsg.rsp", ], - hashes.SHA1, + hashes.SHA1(), only_if=lambda backend: backend.hashes.supported(hashes.SHA1), skip_message="Does not support SHA1", ) @@ -43,7 +43,7 @@ class TestSHA224(object): "SHA224LongMsg.rsp", "SHA224ShortMsg.rsp", ], - hashes.SHA224, + hashes.SHA224(), only_if=lambda backend: backend.hashes.supported(hashes.SHA224), skip_message="Does not support SHA224", ) @@ -57,7 +57,7 @@ class TestSHA256(object): "SHA256LongMsg.rsp", "SHA256ShortMsg.rsp", ], - hashes.SHA256, + hashes.SHA256(), only_if=lambda backend: backend.hashes.supported(hashes.SHA256), skip_message="Does not support SHA256", ) @@ -71,7 +71,7 @@ class TestSHA384(object): "SHA384LongMsg.rsp", "SHA384ShortMsg.rsp", ], - hashes.SHA384, + hashes.SHA384(), only_if=lambda backend: backend.hashes.supported(hashes.SHA384), skip_message="Does not support SHA384", ) @@ -85,7 +85,7 @@ class TestSHA512(object): "SHA512LongMsg.rsp", "SHA512ShortMsg.rsp", ], - hashes.SHA512, + hashes.SHA512(), only_if=lambda backend: backend.hashes.supported(hashes.SHA512), skip_message="Does not support SHA512", ) @@ -98,13 +98,13 @@ class TestRIPEMD160(object): [ "ripevectors.txt", ], - hashes.RIPEMD160, + hashes.RIPEMD160(), only_if=lambda backend: backend.hashes.supported(hashes.RIPEMD160), skip_message="Does not support RIPEMD160", ) test_RIPEMD160_long_string = generate_long_string_hash_test( - hashes.RIPEMD160, + hashes.RIPEMD160(), "52783243c1697bdbe16d37f97f68f08325dc1528", only_if=lambda backend: backend.hashes.supported(hashes.RIPEMD160), skip_message="Does not support RIPEMD160", @@ -118,13 +118,13 @@ class TestWhirlpool(object): [ "iso-test-vectors.txt", ], - hashes.Whirlpool, + hashes.Whirlpool(), only_if=lambda backend: backend.hashes.supported(hashes.Whirlpool), skip_message="Does not support Whirlpool", ) test_whirlpool_long_string = generate_long_string_hash_test( - hashes.Whirlpool, + hashes.Whirlpool(), ("0c99005beb57eff50a7cf005560ddf5d29057fd86b2" "0bfd62deca0f1ccea4af51fc15490eddc47af32bb2b" "66c34ff9ad8c6008ad677f77126953b226e4ed8b01"), @@ -140,7 +140,7 @@ class TestMD5(object): [ "rfc-1321.txt", ], - hashes.MD5, + hashes.MD5(), only_if=lambda backend: backend.hashes.supported(hashes.MD5), skip_message="Does not support MD5", ) diff --git a/tests/hazmat/primitives/test_hashes.py b/tests/hazmat/primitives/test_hashes.py index 797fe4ff..07ab2489 100644 --- a/tests/hazmat/primitives/test_hashes.py +++ b/tests/hazmat/primitives/test_hashes.py @@ -25,39 +25,36 @@ from cryptography.hazmat.primitives import hashes from .utils import generate_base_hash_test -class TestBaseHash(object): - def test_base_hash_reject_unicode(self, backend): - m = hashes.SHA1(backend=backend) +class TestHashContext(object): + def test_hash_reject_unicode(self, backend): + m = hashes.Hash(hashes.SHA1(), backend=backend) with pytest.raises(TypeError): m.update(six.u("\u00FC")) - def test_base_hash_hexdigest_string_type(self, backend): - m = hashes.SHA1(backend=backend, data=b"") - assert isinstance(m.hexdigest(), str) - - -class TestCopyHash(object): def test_copy_backend_object(self): pretend_hashes = pretend.stub(copy_ctx=lambda a: "copiedctx") pretend_backend = pretend.stub(hashes=pretend_hashes) pretend_ctx = pretend.stub() - h = hashes.SHA1(backend=pretend_backend, ctx=pretend_ctx) + h = hashes.Hash(hashes.SHA1(), backend=pretend_backend, + ctx=pretend_ctx) assert h._backend is pretend_backend assert h.copy()._backend is h._backend - -class TestDefaultBackendSHA1(object): def test_default_backend_creation(self): """ This test assumes the presence of SHA1 in the default backend. """ - h = hashes.SHA1() + h = hashes.Hash(hashes.SHA1()) assert h._backend is _default_backend + def test_hash_algorithm_instance(self): + with pytest.raises(TypeError): + hashes.Hash(hashes.SHA1) + class TestSHA1(object): test_SHA1 = generate_base_hash_test( - hashes.SHA1, + hashes.SHA1(), digest_size=20, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.SHA1), @@ -67,7 +64,7 @@ class TestSHA1(object): class TestSHA224(object): test_SHA224 = generate_base_hash_test( - hashes.SHA224, + hashes.SHA224(), digest_size=28, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.SHA224), @@ -77,7 +74,7 @@ class TestSHA224(object): class TestSHA256(object): test_SHA256 = generate_base_hash_test( - hashes.SHA256, + hashes.SHA256(), digest_size=32, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.SHA256), @@ -87,7 +84,7 @@ class TestSHA256(object): class TestSHA384(object): test_SHA384 = generate_base_hash_test( - hashes.SHA384, + hashes.SHA384(), digest_size=48, block_size=128, only_if=lambda backend: backend.hashes.supported(hashes.SHA384), @@ -97,7 +94,7 @@ class TestSHA384(object): class TestSHA512(object): test_SHA512 = generate_base_hash_test( - hashes.SHA512, + hashes.SHA512(), digest_size=64, block_size=128, only_if=lambda backend: backend.hashes.supported(hashes.SHA512), @@ -107,7 +104,7 @@ class TestSHA512(object): class TestRIPEMD160(object): test_RIPEMD160 = generate_base_hash_test( - hashes.RIPEMD160, + hashes.RIPEMD160(), digest_size=20, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.RIPEMD160), @@ -117,7 +114,7 @@ class TestRIPEMD160(object): class TestWhirlpool(object): test_Whirlpool = generate_base_hash_test( - hashes.Whirlpool, + hashes.Whirlpool(), digest_size=64, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.Whirlpool), @@ -127,7 +124,7 @@ class TestWhirlpool(object): class TestMD5(object): test_MD5 = generate_base_hash_test( - hashes.MD5, + hashes.MD5(), digest_size=16, block_size=64, only_if=lambda backend: backend.hashes.supported(hashes.MD5), diff --git a/tests/hazmat/primitives/utils.py b/tests/hazmat/primitives/utils.py index c51fef52..efc5fbf0 100644 --- a/tests/hazmat/primitives/utils.py +++ b/tests/hazmat/primitives/utils.py @@ -4,6 +4,7 @@ import os import pytest from cryptography.hazmat.bindings import _ALL_BACKENDS +from cryptography.hazmat.primitives import hashes from cryptography.hazmat.primitives import hmac from cryptography.hazmat.primitives.block import BlockCipher @@ -65,26 +66,25 @@ def generate_hash_test(param_loader, path, file_names, hash_cls, return test_hash -def hash_test(backend, hash_cls, params, only_if, skip_message): +def hash_test(backend, algorithm, params, only_if, skip_message): if only_if is not None and not only_if(backend): pytest.skip(skip_message) msg = params[0] md = params[1] - m = hash_cls(backend=backend) + m = hashes.Hash(algorithm, backend=backend) m.update(binascii.unhexlify(msg)) - assert m.hexdigest() == md.replace(" ", "").lower() - digst = hash_cls(backend=backend, data=binascii.unhexlify(msg)).hexdigest() - assert digst == md.replace(" ", "").lower() + expected_md = md.replace(" ", "").lower().encode("ascii") + assert m.finalize() == binascii.unhexlify(expected_md) -def generate_base_hash_test(hash_cls, digest_size, block_size, +def generate_base_hash_test(algorithm, digest_size, block_size, only_if=None, skip_message=None): def test_base_hash(self): for backend in _ALL_BACKENDS: yield ( base_hash_test, backend, - hash_cls, + algorithm, digest_size, block_size, only_if, @@ -93,13 +93,14 @@ def generate_base_hash_test(hash_cls, digest_size, block_size, return test_base_hash -def base_hash_test(backend, digestmod, digest_size, block_size, only_if, +def base_hash_test(backend, algorithm, digest_size, block_size, only_if, skip_message): if only_if is not None and not only_if(backend): pytest.skip(skip_message) - m = digestmod(backend=backend) - assert m.digest_size == digest_size - assert m.block_size == block_size + + m = hashes.Hash(algorithm, backend=backend) + assert m.algorithm.digest_size == digest_size + assert m.algorithm.block_size == block_size m_copy = m.copy() assert m != m_copy assert m._ctx != m_copy._ctx @@ -120,12 +121,12 @@ def generate_long_string_hash_test(hash_factory, md, only_if=None, return test_long_string_hash -def long_string_hash_test(backend, hash_factory, md, only_if, skip_message): +def long_string_hash_test(backend, algorithm, md, only_if, skip_message): if only_if is not None and not only_if(backend): pytest.skip(skip_message) - m = hash_factory(backend=backend) + m = hashes.Hash(algorithm, backend=backend) m.update(b"a" * 1000000) - assert m.hexdigest() == md.lower() + assert m.finalize() == binascii.unhexlify(md.lower().encode("ascii")) def generate_hmac_test(param_loader, path, file_names, digestmod, |