simplesamlphp IDP Initiated authentication using existing session

Question

I have a Zend project where users login through a login page backed by a database. I have implemented IdP initiated SSO functionality using simplesamlphp.

Current flow of the events is :-

1. User login into my website.
2. Clicks on the IDP initiated SSO link.
3. User is redirected to the login page I created for SSO login handling. ( Ideally it should happen if user is not logged in. )
4. After login user is sent to the required IDP.
5. After printing $_SESSION here and there I found that this is happening because proper session variables for simplesamlphp is not set.

What I want simplesaml to do is following :-

1. User login into to my website.
2. User click on IdP initiated SSO link.
3. User is redirected to the service provider.

But I am unable to find any method to do so. Please help.

Answer 1

To solve this, I initiated the simplesaml session before making user login using

 SimpleSAML_Session::getInstance(); 
//This method makes the $_SESSION empty and stores the required session parameters it wants.

After this I stored the user's login credentials on the session. I don't know if this is the best way to solve this.