Using SSL to Encrypt a Connection to a DB Instance
You can use SSL from your application to encrypt a connection to a DB instance running MySQL, MariaDB, Amazon Aurora, SQL Server, Oracle, or PostgreSQL. Each DB engine has its own process for implementing SSL. To learn how to implement SSL for your DB instance, use the link following that corresponds to your DB engine:
A root certificate that works for all regions can be downloaded at https://s3.amazonaws.com/rds-downloads/rds-ca-2015-root.pem . It is the trusted root entity and should work in most cases but might fail if your application does not accept certificate chains. If your application does not accept certificate chains, download the region-specific certificate from the list of intermediate certificates found later in this section.
A certificate bundle that contains both the old and new root certificates can be downloaded at https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem .
If your application is on the Microsoft Windows platform and requires a PKCS7 file, you can download the PKCS7 certificate bundle that contains both the old and new certificates at https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.p7b .
If you need an intermediate certificate for a particular region, download the certificate by selecting the region the DB instance resides in from the following list: