Merge branch 'GREG-230-logout-redirect' into 'master'

Redirect on oidc logout

See merge request !306

gregsite/settings/base.py

@@ -165,6 +165,7 @@ OIDC_OP_AUTHORIZATION_ENDPOINT = "https://auth.dataporten.no/oauth/authorization
 OIDC_OP_TOKEN_ENDPOINT = "https://auth.dataporten.no/oauth/token"
 OIDC_OP_USER_ENDPOINT = "https://auth.dataporten.no/openid/userinfo"
 OIDC_OP_FEIDE_EXTENDED_USER_ENDPOINT = "https://api.dataporten.no/userinfo/v1/userinfo"
+OIDC_STORE_ID_TOKEN = True
 
 ALLOW_LOGOUT_GET_METHOD = True
 OIDC_END_SESSION_ENDPOINT = "https://auth.dataporten.no/openid/endsession"

gregui/authentication/auth_backends.py

 import datetime
 import re
 import time
+import urllib.parse
 from typing import Optional
 
 import requests
@@ -689,5 +690,12 @@ class GregOIDCBackend(ValidatingOIDCBackend):
 
 
 def provider_logout(request):
-    redirect_url = settings.OIDC_END_SESSION_ENDPOINT
-    return redirect_url
+    id_token = request.session.get("oidc_id_token")
+    query_params = urllib.parse.urlencode(
+        {
+            "id_token_hint": id_token,
+            "post_logout_redirect_uri": settings.LOGOUT_REDIRECT_URL,
+        }
+    )
+    logout_request_url = f"{settings.OIDC_END_SESSION_ENDPOINT}?{query_params}"
+    return logout_request_url