From bde6fb52129909cf319157dba95d65fb557d5013 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Fri, 18 Oct 2013 18:08:49 -0500 Subject: Hash Saga Part 3 - API changes + SHA1 support + tests --- cryptography/bindings/openssl/api.py | 30 +++++++++++++++++++ cryptography/primitives/hashes.py | 48 ++++++++++++++++++++++++++++++ tests/primitives/test_hash_vectors.py | 35 ++++++++++++++++++++++ tests/primitives/test_hashes.py | 28 ++++++++++++++++++ tests/primitives/test_utils.py | 24 ++++++++++++++- tests/primitives/utils.py | 55 +++++++++++++++++++++++++++++++++++ 6 files changed, 219 insertions(+), 1 deletion(-) create mode 100644 cryptography/primitives/hashes.py create mode 100644 tests/primitives/test_hash_vectors.py create mode 100644 tests/primitives/test_hashes.py diff --git a/cryptography/bindings/openssl/api.py b/cryptography/bindings/openssl/api.py index 79ec5eea..548a9e66 100644 --- a/cryptography/bindings/openssl/api.py +++ b/cryptography/bindings/openssl/api.py @@ -139,5 +139,35 @@ class API(object): assert res != 0 return self.ffi.buffer(buf)[:outlen[0]] + def supports_hash(self, hashname): + return (self.ffi.NULL != + self.lib.EVP_get_digestbyname(hashname.encode("ascii"))) + + def create_hash_context(self, hashobject): + ctx = self.lib.EVP_MD_CTX_create() + ctx = self.ffi.gc(ctx, self.lib.EVP_MD_CTX_destroy) + evp_md = self.lib.EVP_get_digestbyname(hashobject.name.encode("ascii")) + assert evp_md != self.ffi.NULL + res = self.lib.EVP_DigestInit_ex(ctx, evp_md, self.ffi.NULL) + assert res != 0 + return ctx + + def update_hash_context(self, ctx, data): + res = self.lib.EVP_DigestUpdate(ctx, data, len(data)) + assert res != 0 + + def finalize_hash_context(self, ctx, digest_size): + buf = self.ffi.new("unsigned char[]", digest_size) + res = self.lib.EVP_DigestFinal_ex(ctx, buf, self.ffi.NULL) + assert res != 0 + return self.ffi.buffer(buf)[:digest_size] + + def copy_hash_context(self, ctx): + copied_ctx = self.lib.EVP_MD_CTX_create() + copied_ctx = self.ffi.gc(copied_ctx, self.lib.EVP_MD_CTX_destroy) + res = self.lib.EVP_MD_CTX_copy_ex(copied_ctx, ctx) + assert res != 0 + return copied_ctx + api = API() diff --git a/cryptography/primitives/hashes.py b/cryptography/primitives/hashes.py new file mode 100644 index 00000000..d74287f9 --- /dev/null +++ b/cryptography/primitives/hashes.py @@ -0,0 +1,48 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or +# implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from __future__ import absolute_import, division, print_function + +import binascii + +from cryptography.bindings import _default_api + + +class BaseHash(object): + def __init__(self, api=None, ctx=None): + if api is None: + api = _default_api + self._api = api + self._ctx = self._api.create_hash_context(self) if ctx is None else ctx + + def update(self, string): + self._api.update_hash_context(self._ctx, string) + + def copy(self): + return self.__class__(ctx=self._copy_ctx()) + + def digest(self): + return self._api.finalize_hash_context(self._copy_ctx(), + self.digest_size) + + def hexdigest(self): + return binascii.hexlify(self.digest()).decode("ascii") + + def _copy_ctx(self): + return self._api.copy_hash_context(self._ctx) + + +class SHA1(BaseHash): + name = "sha1" + digest_size = 20 + block_size = 64 diff --git a/tests/primitives/test_hash_vectors.py b/tests/primitives/test_hash_vectors.py new file mode 100644 index 00000000..4b71ad70 --- /dev/null +++ b/tests/primitives/test_hash_vectors.py @@ -0,0 +1,35 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or +# implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from __future__ import absolute_import, division, print_function + +import os + +from cryptography.primitives import hashes + +from .utils import generate_hash_test +from ..utils import load_hash_vectors_from_file + + +class TestSHA1(object): + test_SHA1 = generate_hash_test( + load_hash_vectors_from_file, + os.path.join("NIST", "SHABYTE"), + [ + "SHA1LongMsg.rsp", + "SHA1ShortMsg.rsp", + ], + lambda api: hashes.SHA1(api=api), + only_if=lambda api: api.supports_hash("sha1"), + skip_message="Does not support SHA1", + ) diff --git a/tests/primitives/test_hashes.py b/tests/primitives/test_hashes.py new file mode 100644 index 00000000..3419b14d --- /dev/null +++ b/tests/primitives/test_hashes.py @@ -0,0 +1,28 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or +# implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from __future__ import absolute_import, division, print_function + +from cryptography.primitives import hashes + +from .utils import generate_base_hash_test + + +class TestSHA1(object): + test_SHA1 = generate_base_hash_test( + lambda api: hashes.SHA1(api=api), + digest_size=20, + block_size=64, + only_if=lambda api: api.supports_hash("sha1"), + skip_message="Does not support SHA1", + ) diff --git a/tests/primitives/test_utils.py b/tests/primitives/test_utils.py index 4666ece7..43ec8a71 100644 --- a/tests/primitives/test_utils.py +++ b/tests/primitives/test_utils.py @@ -1,6 +1,6 @@ import pytest -from .utils import encrypt_test +from .utils import encrypt_test, hash_test, base_hash_test class TestEncryptTest(object): @@ -12,3 +12,25 @@ class TestEncryptTest(object): skip_message="message!" ) assert exc_info.value.args[0] == "message!" + + +class TestHashTest(object): + def test_skips_if_only_if_returns_false(self): + with pytest.raises(pytest.skip.Exception) as exc_info: + hash_test( + None, None, None, + only_if=lambda api: False, + skip_message="message!" + ) + assert exc_info.value.args[0] == "message!" + + +class TestBaseHashTest(object): + def test_skips_if_only_if_returns_false(self): + with pytest.raises(pytest.skip.Exception) as exc_info: + base_hash_test( + None, None, None, None, + only_if=lambda api: False, + skip_message="message!" + ) + assert exc_info.value.args[0] == "message!" diff --git a/tests/primitives/utils.py b/tests/primitives/utils.py index 3cf08c28..f301199c 100644 --- a/tests/primitives/utils.py +++ b/tests/primitives/utils.py @@ -40,3 +40,58 @@ def encrypt_test(api, cipher_factory, mode_factory, params, only_if, actual_ciphertext = cipher.encrypt(binascii.unhexlify(plaintext)) actual_ciphertext += cipher.finalize() assert actual_ciphertext == binascii.unhexlify(ciphertext) + + +def generate_hash_test(param_loader, path, file_names, hash_factory, + only_if=lambda api: True, skip_message=None): + def test_hash(self): + for api in _ALL_APIS: + for file_name in file_names: + for params in param_loader(os.path.join(path, file_name)): + yield ( + hash_test, + api, + hash_factory, + params, + only_if, + skip_message + ) + return test_hash + + +def hash_test(api, hash_factory, params, only_if, skip_message): + if not only_if(api): + pytest.skip(skip_message) + msg = params[0] + md = params[1] + m = hash_factory(api) + m.update(binascii.unhexlify(msg)) + assert m.hexdigest() == md.replace(" ", "").lower() + + +def generate_base_hash_test(hash_factory, digest_size, block_size, + only_if=lambda api: True, skip_message=None): + def test_base_hash(self): + for api in _ALL_APIS: + yield ( + base_hash_test, + api, + hash_factory, + digest_size, + block_size, + only_if, + skip_message, + ) + return test_base_hash + + +def base_hash_test(api, hash_factory, digest_size, block_size, only_if, + skip_message): + if not only_if(api): + pytest.skip(skip_message) + m = hash_factory(api=api) + assert m.digest_size == digest_size + assert m.block_size == block_size + m_copy = m.copy() + assert m != m_copy + assert m._ctx != m_copy._ctx -- cgit v1.2.3