Allow AL internal UniqueID to be used as attribute

If configured, map AL internal unique id as an attribute to be used
by satosa, microservices and other plugins.

Author: Ioannis Kakavas

example/plugins/microservices/account_linking.yaml.example

@@ -3,4 +3,5 @@ name: AccountLinking
 config:
   api_url: "https://localhost:8167"
   redirect_url: "https://localhost:8167/approve"
-  sign_key: "pki/account_linking.key"
+  sign_key: "pki/account_linking.key"
+  id_to_attr: "uniqueid"

src/satosa/micro_services/account_linking.py

@@ -52,6 +52,10 @@ def _handle_al_response(self, context):
             satosa_logging(logger, logging.INFO, "issuer/id pair is linked in AL service",
                            context.state)
             internal_response.user_id = message
+            id_to_attr = self.config.get("id_to_attr", None)
+            if id_to_attr:
+                internal_response.attributes[id_to_attr] = message
+
             del context.state[self.name]
             return super().process(context, internal_response)
         else:
@@ -76,6 +80,9 @@ def process(self, context, internal_response):
             satosa_logging(logger, logging.INFO, "issuer/id pair is linked in AL service",
                            context.state)
             internal_response.user_id = message
+            id_to_attr = self.config.get("id_to_attr", None)
+            if id_to_attr:
+                internal_response.attributes[id_to_attr] = message
             try:
                 del context.state[self.name]
             except KeyError: