post_logout_redirect_uri is singleton.

Fixed dump conversion.

Author: rohe

src/oidcmsg/impexp.py

@@ -2,6 +2,7 @@
 from typing import List
 from typing import Optional
 
+from cryptojwt import as_unicode
 from cryptojwt.utils import as_bytes
 from cryptojwt.utils import importer
 from cryptojwt.utils import qualified_name
@@ -25,7 +26,7 @@ def __init__(self):
     def dump_attr(self, cls, item, exclude_attributes: Optional[List[str]] = None) -> dict:
         if cls in [None, 0, "", [], {}, bool, b'']:
             if cls == b'':
-                val = as_bytes(item)
+                val = as_unicode(item)
             else:
                 val = item
         elif cls == "DICT_TYPE":

src/oidcmsg/oidc/__init__.py

@@ -633,7 +633,7 @@ class RegistrationRequest(Message):
         # "client_id": SINGLE_OPTIONAL_STRING,
         # "client_secret": SINGLE_OPTIONAL_STRING,
         # "access_token": SINGLE_OPTIONAL_STRING,
-        "post_logout_redirect_uris": OPTIONAL_LIST_OF_STRINGS,
+        "post_logout_redirect_uri": SINGLE_OPTIONAL_STRING,
         "frontchannel_logout_uri": SINGLE_OPTIONAL_STRING,
         "frontchannel_logout_session_required": SINGLE_OPTIONAL_BOOLEAN,
         "backchannel_logout_uri": SINGLE_OPTIONAL_STRING,