Libprocess does not support server only SSL certificate verification.

Currently SSL certificate verification in Libprocess can be configured in the following ways:
(1) send certificate if in server mode, verify peer certificates if present;
(2) require valid peer certificates in both client and server modes.

It is currently impossible to configure a Libprocess instance to simultaneously:
(3) require valid peer certificate in client mode and send certificate in server mode.

Because Libprocess is often used by programs that act both as servers and clients, implementing (3) is necessary to enable the so-called webserver-browser model.