🛂(backend) oidc userinfo endpoint json format

The userinfo endpoint can return 2 content types:
- application/json
- application/jwt

Gitlab oidc returns a json object, while
Agent Connect oidc returns a jwt token.
We are adapting the authentication to handle both cases.

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to
 
 - 🐛 Fix forcing ID when creating a document via API endpoint #234
 - 🐛 Rebuild frontend dev container from makefile #248
+- 🐛 (backend) gitlab oicd userinfo endpoint #232
 
 
 ## [1.3.0] - 2024-09-05

src/backend/core/authentication/backends.py

@@ -18,6 +18,11 @@ class OIDCAuthenticationBackend(MozillaOIDCAuthenticationBackend):
     in the User and Identity models, and handles signed and/or encrypted UserInfo response.
     """
 
+    def is_jwt(self, token):
+        """Check if the token is a JWT token."""
+        parts = token.split(".")
+        return len(parts) == 3
+
     def get_userinfo(self, access_token, id_token, payload):
         """Return user details dictionary.
 
@@ -45,7 +50,16 @@ def get_userinfo(self, access_token, id_token, payload):
             proxies=self.get_settings("OIDC_PROXY", None),
         )
         user_response.raise_for_status()
-        userinfo = self.verify_token(user_response.text)
+
+        try:
+            userinfo = (
+                self.verify_token(user_response.text)
+                if self.is_jwt(user_response.text)
+                else user_response.json()
+            )
+        except ValueError as e:
+            raise SuspiciousOperation(_("Invalid response format")) from e
+
         return userinfo
 
     def get_or_create_user(self, access_token, id_token, payload):