The openacs 5.1.5 config.tcl[1] settings should work without modification. Search for the ns_section ending in "nsopenssl/sslcontext/client" (and subsequent "client" ones here:
http://cvs.openacs.org/cvs/*checkout*/openacs-4/etc/config.tcl
The section includes some brief documentation. Note that there are problems with the config.tcl included with 5.0.0 however --mainly due to the nsopenssl parameters being inconsistent with the code implementation.
The process for creating self-signed certificates for outbound connections are essentially the same for inbound ones:
https://openacs.org/doc/current/install-ssl.html