One of the servers I manage has a Plesk control panel. I am not familiar with it having used cpanel/whm for the last 11 years since I first got a hosted server.

I was setting up what I thought would be an easy SSL certificate install. I’ve started this post because I am now delving into the core of the server <supposition>as the damn GUI hates me.</supposition>

Before you even start, if you want to have an SSL certificate on a sub-domain site, forget it unless you a) make it a wildcard certificate or b) are prepared to have the only ip address attached to that certificate.

Plesk 10.x only allows one IP address per subscription and that is set for all the sub-domains as well as the domain attached to the subscription.

So to apply a certificate that works for the subscription it must be a wildcard certificate. i.e.

subscription_domain.tld

sub-domains exist for

site1.subscription_domain.tld
site2.subscription_domain.tld

certificate is for

subscription_domain.tld

it will be applied to all the domains

https://subscription_domain.tld
https://site1.subscription_domain.tld
https://site2.subscription_domain.tld

While the option to have a specific SSL for

site1.subscription_domain.tld
and
site2.subscription_domain.tld

as it is not possible to split the IP addresses to isolate the SSL per IP address.