The rui.crt for vCenter can be grabbed (assuming your server is 192.168.1.2) by:
openssl s_client -connect 192.168.1.2:443 < /dev/null | \
sed
-ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' >
rui-192.168.1.2.crt
So what’s up with this? When installing my company’s product, we always go through this goose-chase to find a rui.crt. Seriously, it’s a pain, we need to dig through a bunch of directories, and in the end, sometimes we’re still scratching our heads.
Our customers just want something they can cut-n-paste. Of course, the line above only works on non-windows, but I have reduced concern for those trying to fly with wings of lead: there’s a limit as to what you can do with windows. Accept it.