These days, I was working hard about using MariaDB with Secure Connections. First, I did SHOW VARIABLES LIKE 'have_ssl'; and got this:
+---------------+----------+ | Variable_name | Value | +---------------+----------+ | have_ssl | DISABLED | +---------------+----------+
DISABLED means that the server was compiled with TLS support, but was not started with TLS support. So I can use MariaDB with Secure Connections on my server.