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author | Simo Sorce <simo@redhat.com> | 2015-04-30 14:06:47 -0400 |
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committer | Simo Sorce <simo@redhat.com> | 2015-10-17 11:58:07 -0400 |
commit | 9aaeee0dc62189204f38097c815a0913fabe006c (patch) | |
tree | 37621d2d6a20898d9665520a30ecb7a68c0db30e /tests/hazmat/primitives/test_ec.py | |
parent | 7a0ed4a7e9443a0506ae5373a8e5cd1ce3539e97 (diff) | |
download | cryptography-9aaeee0dc62189204f38097c815a0913fabe006c.tar.gz cryptography-9aaeee0dc62189204f38097c815a0913fabe006c.tar.bz2 cryptography-9aaeee0dc62189204f38097c815a0913fabe006c.zip |
Add an Elliptic Curve Key Exchange Algorithm(ECDH)
The ECDH Key Exchange algorithm as standardized in NIST publication
800-56A Revision 2
Includes tests with vectors from NIST.
Signed-off-by: Simo Sorce <simo@redhat.com>
Diffstat (limited to 'tests/hazmat/primitives/test_ec.py')
-rw-r--r-- | tests/hazmat/primitives/test_ec.py | 94 |
1 files changed, 93 insertions, 1 deletions
diff --git a/tests/hazmat/primitives/test_ec.py b/tests/hazmat/primitives/test_ec.py index 5467464a..c3a99e5d 100644 --- a/tests/hazmat/primitives/test_ec.py +++ b/tests/hazmat/primitives/test_ec.py @@ -7,6 +7,8 @@ from __future__ import absolute_import, division, print_function import itertools import os +from binascii import hexlify + import pytest from cryptography import exceptions, utils @@ -21,7 +23,8 @@ from cryptography.hazmat.primitives.asymmetric.utils import ( from ...utils import ( load_fips_ecdsa_key_pair_vectors, load_fips_ecdsa_signing_vectors, - load_vectors_from_file, raises_unsupported_algorithm + load_kasvs_ecdh_vectors, load_vectors_from_file, + raises_unsupported_algorithm ) _HASH_TYPES = { @@ -54,6 +57,15 @@ def _skip_curve_unsupported(backend, curve): ) +def _skip_exchange_algorithm_unsupported(backend): + if not backend.elliptic_curve_exchange_algorithm_supported(): + pytest.skip( + "Exchange algorithm is not supported by this backend {0}".format( + backend + ) + ) + + @utils.register_interface(ec.EllipticCurve) class DummyCurve(object): name = "dummy-curve" @@ -749,3 +761,83 @@ class TestECDSAVerification(object): public_key = key.public_key() with pytest.raises(TypeError): public_key.verifier(1234, ec.ECDSA(hashes.SHA256())) + + +class DummyECDHBackend(object): + @classmethod + def elliptic_curve_exchange_algorithm_supported(cls): + return False + + +@pytest.mark.requires_backend_interface(interface=EllipticCurveBackend) +class TestECDHVectors(object): + + def test_unsupported_ecdh_arguments(self, backend): + with pytest.raises(TypeError): + ec.ECDH(None) + curve = ec.SECP521R1 + _skip_curve_unsupported(backend, curve) + prikey = ec.generate_private_key(curve, backend) + ecdh = ec.ECDH(prikey) + ecdh.compute_key(ecdh.public_key()) + with pytest.raises(TypeError): + ecdh.compute_key(None) + with pytest.raises(exceptions.UnsupportedAlgorithm): + prikey._backend = DummyECDHBackend() + ecdh = ec.ECDH(prikey) + _skip_exchange_algorithm_unsupported(DummyECDHBackend()) + + def key_exchange(self, backend, vector): + key_numbers = vector['IUT'] + peer_numbers = vector['CAVS'] + + prikey = ec.EllipticCurvePrivateNumbers( + key_numbers['d'], + ec.EllipticCurvePublicNumbers( + key_numbers['x'], + key_numbers['y'], + ec._CURVE_TYPES[vector['curve']]() + ) + ).private_key(backend) + + peerkey = ec.EllipticCurvePrivateNumbers( + peer_numbers['d'], + ec.EllipticCurvePublicNumbers( + peer_numbers['x'], + peer_numbers['y'], + ec._CURVE_TYPES[vector['curve']]() + ) + ).private_key(backend) + peerpubkey = peerkey.public_key() + + ecdh = ec.ECDH(prikey) + z = ecdh.compute_key(peerpubkey) + + return int(hexlify(z).decode('ascii'), 16) + + @pytest.mark.parametrize( + "vector", + load_vectors_from_file( + os.path.join( + "asymmetric", "ECDH", + "KASValidityTest_ECCStaticUnified_NOKC_ZZOnly_init.fax"), + load_kasvs_ecdh_vectors + ) + ) + def test_key_exchange_with_vectors(self, backend, vector): + _skip_curve_unsupported(backend, ec._CURVE_TYPES[vector['curve']]) + _skip_exchange_algorithm_unsupported(backend) + + try: + z = self.key_exchange(backend, vector) + except ValueError: + assert vector['fail'] is True + + if vector['fail']: + # Errno 7 denotes a changed private key. Errno 8 denotes a changed + # shared key. Both these errors will not cause a failure in the + # exchange but should lead to a non-matching derived shared key. + if vector['errno'] in [7, 8]: + assert z != vector['Z'] + else: + assert z == vector['Z'] |