Certificate Presentation

First, a peer certificate must be presented. Servers generally always have a certificate to present, as it is required by SSL. Client certificates are optional in SSL however, so remote browsers (or remote Vortex clients) may have to have a certificate configured (e.g. via sslcertificatefile, here). Note that if the sslverifyserver or SSL Verify Client setting is "optional" (or contains "-No_Peer_Certificate"), failure to present a certificate is not an error (though presented certificates still go through the checks that follow); this may reduce security however.