I tryed to implement SimpleSAMLPHP (https://simplesamlphp.org/) with Symfony 2.4+ (http://symfony.com/). But since Symfony is managing the sessions, it destroy the SimpleSAML session before that one has been write.
Does anyone solve this problem ? I'm currently moving to another SAML library : onelogin/php-saml (https://github.com/onelogin/php-saml)