UniFi ID SAML Error

[huslage]

Describe the bug

I have set up a new SAML application in UniFi Identity (UID) that points to my Jellyfin instance. At first it was complaining about the ACS URL being wrong. It appears that the current documentation contains the wrong URL to be set up. After analyzing the error response, I put the correct ACS URL into the UID config. Now I'm getting a valid SAML Response, but the Linking page still shows an error: jellyfin log file extract

To Reproduce Steps to reproduce the behavior:

• Configure the saml endpoint by doing a POST to: /jellyfin/sso/SAML/Add/UID?api_key=[API_KEY] JSON Payload
• Visit jellyfin/SSOViews/linking in the browser and click the + button.
• SAML linking begins and the IdP sends back a success, however the linking fails with Error processing request. when redirected to jellyfin/sso/SAML/p/UID
• Log file shows that the response was not parseable.
• Use base64 -d -i file.b64 to verify that the response is indeed parseable (I can email you this base64 encoded response, but I don't want to share it publicly.)

Expected behavior I would expect the successful response from the IdP would be parsed and the linking would succeed.

Screenshots See this Gist

Configuration

See this Gist

Versions (please complete the following information):

• OS: MacOS 13.5.1
• Browser: Firefox
• Jellyfin Version: 10.8.10
• Plugin Version: 3.5.2.0

Additional context Jellyfin Mac App from the website. Installed plugin from repo listed in README.md.