Upgrade notes for SimpleSAMLphp 2.1

SimpleSAMLphp 2.1 is a minor new release which bumps some of the minimum requirements to be able to run SimpleSAMLphp. The following changes are relevant for installers and/or developers.

Software requirements

• The minimum PHP version required is now PHP 8.0.
• Dropped support for Symfony 5.4.

Two builds

As of SimpleSAMLphp 2.1 two builds are created for every release. The 'slim' build is a lightweight build without any modules other than the core modules installed (alike the 2.0 build). A new 'full' build is added that will come with the most used modules pre-installed.

Default security-headers

The default security headers have been adjusted to a more strict set. This may cause issues if you use any modules or custom themes that use inline CSS or JavaScript. You can adjust these settings in config.php using the headers.security setting, but we recommend updating the custom module/theme and move and inline CSS or JavaScript to a file. All modules within the simplesamlphp/* namespace are fixed and should not cause any issues.