Michael Webster at Long White Virtual Clouds has a great post on changing the SSL certificates for the vCenter Server Virtual Appliance (VCVA):

…because the vCenter Server Virtual Appliance is Suse Linux Enterprise Server based you will have to be used to a Linux command line, using scp, and generally navigating around in order to successfully change your certificates. All operations will be done as root. The default password is vmware. Like in my previous articles regarding changing SSL Certificates I have included an example OpenSSL configuration file that you can use to generate your certificates.

The following directories on the VCVA contain SSL certificates in one form or another:

/opt/vmware/etc/lighttpd/

/etc/vmware-vpx/ssl

/usr/lib/vmware-vpx/inventoryservice/ssl

/usr/lib/vmware-vsphere-client/server/config

I will go through what needs to go where after I’ve given you what you need to create the certificates.