Hi,
usually vCenter generates the certificates for the connected ESXi hosts. This is done by the VMCA and can be triggered by the vCenter GUI => Browser to the ESXi Host -> System -> Configure -> Certificate -> Renew.
To generate a new ESXi Host certificate, which is used for https connections at TCP/443 and for the CIM service TCP/5989, a script is located in /sbin.
Set the host into maintenance mode and remove it from the cluster
Call
~ # /sbin/generate-certificates
to generate a new host certificate and restart services
~ # /etc/init.d/sfcbd-watchdog restart ~ # /sbin/services.sh restart
reconnect the host to the cluster
Michael