First we took the SAML code sample references from https://github.com/onelogin/php-saml and set up the integration with our project.
Before going to company SSO, we created trial account with a third party service provider one login, to test our code for Single sign on is proper.
On local this worked perfectly. We deployed same on GCP with changed references and test failed. Next we went with our company SSO on GCP with certificates and necessary changes. It failed in similar manner as as not authenticated
- When the site is accessed redirection to company sso OK
- Successful Authentication at company SSO and redirection back to Application OK
- Validating the response from company SSO in the application NO
On using SAML Tracer it was clear that the authentication at the company SSO side was proper, only that our code wasn’t able to receive it properly.
Since on local things are working as intended we doubt with respect to GAE/PHP we may be missing something as the application cannot verify the object returned from SSO, may be losing cache/session.
we are using Google app engine standard with our application being PHP 7.4