core (memory/encryption): helper method to get currently utilised e2ee algorithm's namespace:

rel 379

sat/memory/encryption.py

@@ -346,6 +346,18 @@ class EncryptionHandler:
             raise ValueError("Full jid given when expecting bare jid")
         return self._sessions.get(entity)
 
+    def get_namespace(self, entity: jid.JID) -> Optional[str]:
+        """Helper method to get the current encryption namespace used
+
+        @param entity: get the namespace for this entity must be a bare jid
+        @return: the algorithm namespace currently used in this session, or None if no
+            e2ee is currently used.
+        """
+        session = self.getSession(entity)
+        if session is None:
+            return None
+        return session["plugin"].namespace
+
     def getTrustUI(self, entity_jid, namespace=None):
         """Retrieve encryption UI