ELB and Backend Authentication with Apache 2.4

Question

I tried looking at AWS guides, and other things but can't seem to figure this one out. When using ELB there is a backend authentication option. I want to enable it, but I am not sure what certificate to use. We currently have a key from GoDaddy with a certificate chain added on. The cert is working with the ELB no issues, but backend is current disabled. It is asking for a backend certificate. Which file do I use for this? The GoDaddy cert?

Answer 1

Yes and no... it depends.

If you've installed that same cert on the backend server, then, yes, that's the correct cert to use in ELB for backend auth.

Otherwise, no, if your backend machines use a different cert, then you want to use the certificate installed on the backend machines, instead.

You need to verify that you are able to connect directly from a browser to the backend server using SSL, independent of the ELB, before backend auth will work. If the backend isn't correctly configured for SSL in general, it's much easier to troubleshoot this independently of ELB, since ELB doesn't offer much in the way of explanation when the backend SSL negotiation isn't working.