diff options
Diffstat (limited to 'tests/hazmat/primitives/test_dh.py')
| -rw-r--r-- | tests/hazmat/primitives/test_dh.py | 207 |
1 files changed, 195 insertions, 12 deletions
diff --git a/tests/hazmat/primitives/test_dh.py b/tests/hazmat/primitives/test_dh.py index d8869de9..ba724bf0 100644 --- a/tests/hazmat/primitives/test_dh.py +++ b/tests/hazmat/primitives/test_dh.py @@ -4,22 +4,27 @@ from __future__ import absolute_import, division, print_function +import os + import pytest +from cryptography.hazmat.backends.interfaces import DHBackend from cryptography.hazmat.primitives.asymmetric import dh +from cryptography.utils import bit_length, int_from_bytes +from ...utils import load_nist_vectors, load_vectors_from_file def test_dh_parameternumbers(): params = dh.DHParameterNumbers( - 65537, 3 + 65537, 2 ) assert params.p == 65537 - assert params.g == 3 + assert params.g == 2 with pytest.raises(TypeError): dh.DHParameterNumbers( - None, 3 + None, 2 ) with pytest.raises(TypeError): @@ -32,10 +37,15 @@ def test_dh_parameternumbers(): None, None ) + with pytest.raises(ValueError): + dh.DHParameterNumbers( + 65537, 7 + ) + def test_dh_numbers(): params = dh.DHParameterNumbers( - 65537, 3 + 65537, 2 ) public = dh.DHPublicNumbers( @@ -74,14 +84,14 @@ def test_dh_numbers(): def test_dh_parameter_numbers_equality(): - assert dh.DHParameterNumbers(65537, 3) == dh.DHParameterNumbers(65537, 3) - assert dh.DHParameterNumbers(6, 3) != dh.DHParameterNumbers(65537, 3) - assert dh.DHParameterNumbers(65537, 0) != dh.DHParameterNumbers(65537, 3) - assert dh.DHParameterNumbers(65537, 0) != object() + assert dh.DHParameterNumbers(65537, 2) == dh.DHParameterNumbers(65537, 2) + assert dh.DHParameterNumbers(6, 2) != dh.DHParameterNumbers(65537, 2) + assert dh.DHParameterNumbers(65537, 5) != dh.DHParameterNumbers(65537, 2) + assert dh.DHParameterNumbers(65537, 2) != object() def test_dh_private_numbers_equality(): - params = dh.DHParameterNumbers(65537, 3) + params = dh.DHParameterNumbers(65537, 2) public = dh.DHPublicNumbers(1, params) private = dh.DHPrivateNumbers(2, public) @@ -89,16 +99,189 @@ def test_dh_private_numbers_equality(): assert private != dh.DHPrivateNumbers(0, public) assert private != dh.DHPrivateNumbers(2, dh.DHPublicNumbers(0, params)) assert private != dh.DHPrivateNumbers( - 2, dh.DHPublicNumbers(1, dh.DHParameterNumbers(65537, 0)) + 2, dh.DHPublicNumbers(1, dh.DHParameterNumbers(65537, 5)) ) assert private != object() def test_dh_public_numbers_equality(): - params = dh.DHParameterNumbers(65537, 3) + params = dh.DHParameterNumbers(65537, 2) public = dh.DHPublicNumbers(1, params) assert public == dh.DHPublicNumbers(1, params) assert public != dh.DHPublicNumbers(0, params) - assert public != dh.DHPublicNumbers(1, dh.DHParameterNumbers(65537, 0)) + assert public != dh.DHPublicNumbers(1, dh.DHParameterNumbers(65537, 5)) assert public != object() + + +@pytest.mark.requires_backend_interface(interface=DHBackend) +class TestDH(object): + def test_small_key_generate_dh(self, backend): + with pytest.raises(ValueError): + dh.generate_parameters(2, 511, backend) + + def test_unsupported_generator_generate_dh(self, backend): + with pytest.raises(ValueError): + dh.generate_parameters(7, 512, backend) + + def test_dh_parameters_supported(self, backend): + assert backend.dh_parameters_supported(23, 5) + assert not backend.dh_parameters_supported(23, 18) + + def test_convert_to_numbers(self, backend): + parameters = backend.generate_dh_private_key_and_parameters(2, 512) + + private = parameters.private_numbers() + + p = private.public_numbers.parameter_numbers.p + g = private.public_numbers.parameter_numbers.g + + params = dh.DHParameterNumbers(p, g) + public = dh.DHPublicNumbers(1, params) + private = dh.DHPrivateNumbers(2, public) + + deserialized_params = params.parameters(backend) + deserialized_public = public.public_key(backend) + deserialized_private = private.private_key(backend) + + assert isinstance(deserialized_params, + dh.DHParametersWithSerialization) + assert isinstance(deserialized_public, + dh.DHPublicKeyWithSerialization) + assert isinstance(deserialized_private, + dh.DHPrivateKeyWithSerialization) + + def test_numbers_unsupported_parameters(self, backend): + params = dh.DHParameterNumbers(23, 2) + public = dh.DHPublicNumbers(1, params) + private = dh.DHPrivateNumbers(2, public) + + with pytest.raises(ValueError): + private.private_key(backend) + + def test_generate_dh(self, backend): + generator = 2 + key_size = 512 + + parameters = dh.generate_parameters(generator, key_size, backend) + assert isinstance(parameters, dh.DHParameters) + + key = parameters.generate_private_key() + assert isinstance(key, dh.DHPrivateKey) + assert key.key_size == key_size + + public = key.public_key() + assert isinstance(public, dh.DHPublicKey) + assert public.key_size == key_size + + assert isinstance(parameters, dh.DHParametersWithSerialization) + parameter_numbers = parameters.parameter_numbers() + assert isinstance(parameter_numbers, dh.DHParameterNumbers) + assert bit_length(parameter_numbers.p) == key_size + + assert isinstance(public, dh.DHPublicKeyWithSerialization) + assert isinstance(public.public_numbers(), dh.DHPublicNumbers) + assert isinstance(public.parameters(), dh.DHParameters) + + assert isinstance(key, dh.DHPrivateKeyWithSerialization) + assert isinstance(key.private_numbers(), dh.DHPrivateNumbers) + assert isinstance(key.parameters(), dh.DHParameters) + + def test_exchange(self, backend): + parameters = dh.generate_parameters(2, 512, backend) + assert isinstance(parameters, dh.DHParameters) + + key1 = parameters.generate_private_key() + key2 = parameters.generate_private_key() + + symkey1 = key1.exchange(key2.public_key()) + assert symkey1 + assert len(symkey1) == 512 // 8 + + symkey2 = key2.exchange(key1.public_key()) + assert symkey1 == symkey2 + + def test_exchange_algorithm(self, backend): + parameters = dh.generate_parameters(2, 512, backend) + + key1 = parameters.generate_private_key() + key2 = parameters.generate_private_key() + + shared_key_bytes = key2.exchange(key1.public_key()) + symkey = int_from_bytes(shared_key_bytes, 'big') + + symkey_manual = pow(key1.public_key().public_numbers().y, + key2.private_numbers().x, + parameters.parameter_numbers().p) + + assert symkey == symkey_manual + + def test_symmetric_key_padding(self, backend): + """ + This test has specific parameters that produce a symmetric key + In length 63 bytes instead 64. We make sure here that we add + padding to the key. + """ + p = int("11859949538425015739337467917303613431031019140213666" + "129025407300654026585086345323066284800963463204246390" + "256567934582260424238844463330887962689642467123") + g = 2 + y = int("32155788395534640648739966373159697798396966919821525" + "72238852825117261342483718574508213761865276905503199" + "969908098203345481366464874759377454476688391248") + x = int("409364065449673443397833358558926598469347813468816037" + "268451847116982490733450463194921405069999008617231539" + "7147035896687401350877308899732826446337707128") + parameters = dh.DHParameterNumbers(p, g) + public = dh.DHPublicNumbers(y, parameters) + private = dh.DHPrivateNumbers(x, public) + key = private.private_key(backend) + symkey = key.exchange(public.public_key(backend)) + assert len(symkey) == 512 // 8 + assert symkey[:1] == b'\x00' + + @pytest.mark.parametrize( + "vector", + load_vectors_from_file( + os.path.join("asymmetric", "DH", "bad_exchange.txt"), + load_nist_vectors)) + def test_bad_exchange(self, backend, vector): + parameters1 = dh.DHParameterNumbers(int(vector["p1"]), + int(vector["g"])) + public1 = dh.DHPublicNumbers(int(vector["y1"]), parameters1) + private1 = dh.DHPrivateNumbers(int(vector["x1"]), public1) + key1 = private1.private_key(backend) + pub_key1 = key1.public_key() + + parameters2 = dh.DHParameterNumbers(int(vector["p2"]), + int(vector["g"])) + public2 = dh.DHPublicNumbers(int(vector["y2"]), parameters2) + private2 = dh.DHPrivateNumbers(int(vector["x2"]), public2) + key2 = private2.private_key(backend) + pub_key2 = key2.public_key() + + if pub_key2.public_numbers().y >= parameters1.p: + with pytest.raises(ValueError): + key1.exchange(pub_key2) + else: + symkey1 = key1.exchange(pub_key2) + assert symkey1 + + symkey2 = key2.exchange(pub_key1) + + assert symkey1 != symkey2 + + @pytest.mark.parametrize( + "vector", + load_vectors_from_file( + os.path.join("asymmetric", "DH", "vec.txt"), + load_nist_vectors)) + def test_dh_vectors(self, backend, vector): + parameters = dh.DHParameterNumbers(int(vector["p"]), + int(vector["g"])) + public = dh.DHPublicNumbers(int(vector["y"]), parameters) + private = dh.DHPrivateNumbers(int(vector["x"]), public) + key = private.private_key(backend) + symkey = key.exchange(public.public_key(backend)) + + assert int_from_bytes(symkey, 'big') == int(vector["k"], 16) |