How to add SSL to subdomain that points to a different server?

Question

I don't know much about secure certificates, so please bear with me...

I've got a webserver that has a single domain SSL certificate

https://secure.mysite.com

I also have a couple of subdomains that point to different servers.

http://www.mysite.com ( main server) 

http://subdomain.mysite.com (completely different server)

I am wondering: What is the best way to add SSL to the subdomain:

https://subdomain.mysite.com

Is it possible to configure something like this with a wildcard certificate? Or is it better to purchase another single-domain certificate and install it on the seperate server?

Are there any special considerations / pitfalls in doing something like this?

Thanks, in advance, for your help.

Answer 1

Wild card certificates only cover domains on the same server. I believe it's because the key used in the certificate is tied back to the server.

If you want to add a certificate for sites on other servers you will need specific certificates for those server/domain combinations.

Answer 2

You can get a wildcard cert but that is probably more expensive than you need and you'd need to copy your private key to each server -- which really is not recommended unless you are a crypto expert. You are better off simply purchasing two more certs for the two additional machines.