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, 8 insertions, 2 deletions

diff --git a/src/cryptography/hazmat/primitives/asymmetric/x448.py b/src/cryptography/hazmat/primitives/asymmetric/x448.py
index 69bfa408..992ec0fd 100644
--- a/src/cryptography/hazmat/primitives/asymmetric/x448.py
+++ b/src/cryptography/hazmat/primitives/asymmetric/x448.py
@@ -25,7 +25,7 @@ class X448PublicKey(object):
         return backend.x448_load_public_bytes(data)
 
     @abc.abstractmethod
-    def public_bytes(self):
+    def public_bytes(self, encoding, format):
         """
         The serialized bytes of the public key.
         """
@@ -44,7 +44,7 @@ class X448PrivateKey(object):
         return backend.x448_generate_key()
 
     @classmethod
-    def _from_private_bytes(cls, data):
+    def from_private_bytes(cls, data):
         from cryptography.hazmat.backends.openssl.backend import backend
         return backend.x448_load_private_bytes(data)
 
@@ -55,6 +55,12 @@ class X448PrivateKey(object):
         """
 
     @abc.abstractmethod
+    def private_bytes(self, encoding, format, encryption_algorithm):
+        """
+        The serialized bytes of the private key.
+        """
+
+    @abc.abstractmethod
     def exchange(self, peer_public_key):
         """
         Performs a key exchange operation using the provided peer's public key.