Attempt 2 at fixing crypto

mastodon/Mastodon.py

@@ -27,6 +27,7 @@ try:
     import cryptography
     from cryptography.hazmat.backends import default_backend
     from cryptography.hazmat.primitives.asymmetric import ec
+    from cryptography.hazmat.primitives import serialization
 except:
     IMPL_HAS_CRYPTO = False
     
@@ -2588,8 +2589,12 @@ class Mastodon:
         
         push_key_pair = ec.generate_private_key(ec.SECP256R1(), default_backend())
         push_key_priv = push_key_pair.private_numbers().private_value
-        if bigger_version(cryptography.__version__, "2.5.0") == cryptography.__version__:
-            push_key_pub = push_key_pair.public_key().public_numbers().public_bytes() 
+        
+        crypto_ver = cryptography.__version__
+        if len(crypto_ver) > 5:
+            crypto_ver += ".0"
+        if bigger_version(crypto_ver, "2.5.0") == crypto_ver:
+            push_key_pub = push_key_pair.public_key().public_bytes(serialization.Encoding.X962, serialization.PublicFormat.UncompressedPoint)
         else:
             push_key_pub = push_key_pair.public_key().public_numbers().encode_point() 
         push_shared_secret = os.urandom(16)