Hello,
Did you find a solution? I am curious because I am researching ArcGIS Server security. My organization is will be using either arcGIS Server authentication or web authentication. Any advice will be appreciated!
"Generate" will generate a Certificate Signing Request for you to send to a CA to have the default certificate "authenticated" with a real trust chain. When you installed Server, by default, a self-signed certificate was provisioned. Have you enabled HTTP and HTTPS on your Arc GIS Server? If so, you should be able to hit
https://[host name]:6443/arcgis/admin
However, if you're going through the trouble to ssl-enable an ArcGIS Site, I'd consider using a Web Adaptor in front of it, as well as upgrading to 10.3 or higher.