How to check what SSL/TLS protocols are enabled in Apache configuration

Question

How to check what SSL/TLS protocols are enabled in Apache configuration?

Answer

SSL/TLS protocols used by Apache are defined by the "SSLProtocol" Apache directive. To check which protocols are allowed:

1. Connect to a Plesk server via SSH.

2. Run the command:

   • on CentOS/RHEL-based distributions

     # grep SSLProtocol /etc/httpd/conf.d/ssl.conf

     SSLProtocol +TLSv1.2

   • on Debian/Ubuntu-based distributions

     # grep -ir SSLProtocol /etc/apache2/*

     /etc/apache2/mods-available/ssl.conf:SSLProtocol +TLSv1.2 +TLSv1.3

      

     To enable/disable SSL/TLS protocols, see this KB article.