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>

1 files changed, 14 insertions, 0 deletions

diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py
index 8fd0d711..13162046 100644
--- a/tests/hazmat/backends/test_openssl.py
+++ b/tests/hazmat/backends/test_openssl.py
@@ -534,6 +534,11 @@ class DummyLibrary(object):
     Cryptography_HAS_EC = 0
 
 
+class DummyLibraryECDH(object):
+    Cryptography_HAS_EC = 1
+    Cryptography_HAS_ECDH = 0
+
+
 class TestOpenSSLEllipticCurve(object):
     def test_elliptic_curve_supported(self, monkeypatch):
         monkeypatch.setattr(backend, "_lib", DummyLibrary())
@@ -551,6 +556,15 @@ class TestOpenSSLEllipticCurve(object):
         with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_ELLIPTIC_CURVE):
             _sn_to_elliptic_curve(backend, b"fake")
 
+    def test_elliptic_curve_exchange_algorithm_supported(self, monkeypatch):
+        monkeypatch.setattr(backend, "_lib", DummyLibrary())
+
+        assert backend.elliptic_curve_exchange_algorithm_supported() is False
+
+        monkeypatch.setattr(backend, "_lib", DummyLibraryECDH())
+
+        assert backend.elliptic_curve_exchange_algorithm_supported() is False
+
 
 @pytest.mark.requires_backend_interface(interface=RSABackend)
 class TestRSAPEMSerialization(object):