Explicitly pass around the API, and run all tests under all available APIs
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..d16be3b
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,5 @@
+def pytest_generate_tests(metafunc):
+    from cryptography.bindings.openssl import api
+
+    if "api" in metafunc.fixturenames:
+        metafunc.parametrize("api", [api])