amazon-web-services mysql rds ssl wordpress

Using amazon RDS with WordPress over SSL

I’m migrating our WordPress database to RDS which is also being used by other services in our infrastructure. But I couldn’t find any configuration option for wp-config.php where I could specify that SSL to be used while connecting to the server. This would also need a reference to the certificate authority file provided by Amazon. The app server on which WordPress is currently running, is outside AWS cluster.

The answers I could find were fairly old (I’m using WordPress 4.2 here) and don’t provide much guidance.

How can I configure WordPress to use Amazon RDS over an SSL connection (specifying the public key)?