support x448 public/private serialization both raw and pkcs8 (#4653)

* support x448 public/private serialization both raw and pkcs8

* add tests for all other asym key types to prevent Raw

* more tests

* better tests

* fix a test

* funny story, I'm actually illiterate.

* pep8

* require PrivateFormat.Raw or PublicFormat.Raw with Encoding.Raw

* missing docs

* parametrize

* docs fixes

* remove dupe line

* assert something

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/hazmat/primitives/test_dh.py b/tests/hazmat/primitives/test_dh.py
index a70ae745..c63e520f 100644
--- a/tests/hazmat/primitives/test_dh.py
+++ b/tests/hazmat/primitives/test_dh.py
@@ -425,6 +425,20 @@ class TestDHPrivateKeySerialization(object):
         assert loaded_priv_num == priv_num
 
     @pytest.mark.parametrize(
+        ("encoding", "fmt"),
+        [
+            (serialization.Encoding.Raw, serialization.PrivateFormat.PKCS8),
+            (serialization.Encoding.DER, serialization.PrivateFormat.Raw),
+            (serialization.Encoding.Raw, serialization.PrivateFormat.Raw),
+        ]
+    )
+    def test_private_bytes_rejects_raw(self, encoding, fmt, backend):
+        parameters = dh.generate_parameters(2, 512, backend)
+        key = parameters.generate_private_key()
+        with pytest.raises(ValueError):
+            key.private_bytes(encoding, fmt, serialization.NoEncryption())
+
+    @pytest.mark.parametrize(
         ("key_path", "loader_func", "encoding", "is_dhx"),
         [
             (
@@ -806,6 +820,23 @@ class TestDHParameterSerialization(object):
         else:
             assert parameter_numbers.q is None
 
+    @pytest.mark.parametrize(
+        ("encoding", "fmt"),
+        [
+            (serialization.Encoding.Raw, serialization.PublicFormat.Raw),
+            (serialization.Encoding.PEM, serialization.PublicFormat.Raw),
+            (
+                serialization.Encoding.Raw,
+                serialization.PublicFormat.SubjectPublicKeyInfo
+            ),
+        ]
+    )
+    def test_public_bytes_rejects_raw(self, encoding, fmt, backend):
+        parameters = dh.generate_parameters(2, 512, backend)
+        key = parameters.generate_private_key().public_key()
+        with pytest.raises(ValueError):
+            key.public_bytes(encoding, fmt)
+
     def test_parameter_bytes_invalid_encoding(self, backend):
         parameters = dh.generate_parameters(2, 512, backend)
         with pytest.raises(TypeError):