PostgreSQL™ provides a way for developers to customize how a SSL connection is established. This may be used to provide a custom certificate source or other extensions by allowing the developer to create their own SSLContext instance. The connection URL parameters sslfactory and sslfactoryarg allow the user to specify which custom class to use for creating the SSLSocketFactory. The class name specified by sslfactory must extend javax.net.ssl.SSLSocketFactory and be available to the driver's classloader. This class must have a zero argument constructor or a single argument constructor taking a String argument. This argument may optionally be supplied by sslfactoryarg.

Information on how to actually implement such a class is beyond the scope of this documentation. Places to look for help are the JSSE Reference Guide and the source to the NonValidatingFactory provided by the JDBC driver.

The Java SSL API is not very well known to the JDBC driver developers and we would be interested in any interesting and generally useful extensions that you have implemented using this mechanism. Specifically it would be nice to be able to provide client certificates to be validated by the server.