I have a problem with Apache certs in a really paranoid organisation which wants to keep the private key as secure as possible.

I could encrypt the key, but this requires a passphrase dialogue on service start/restart, which probably won't fly with them.

Also could automate passphrase entry, but this requires that the passphrase is stored somewhere that the box can get to, even less likely to fly.

So, I was wondering if I could leverage SELinux to restrict access to the private key to the httpd process. i.e. no users, even root, would be able to view (vi or cat etc) or copy the file.

However, I have no idea how to do this, or even if it's possible, does anyone have a clue?

SELinux, or rather its default "targeted" policy, is a "hard on the outside, chewy on the inside" policy: it tightens security for 'net-facing services confining them to their own context while leaving movement of local users mostly unrestricted. I'd venture you would either need to strip out and redefine parts of the current policy or build a MLS policy yourself to accomplish what you want.

The problem is that apache must be able to access the key to decrypt the stream... If apache can access the key, then a vulnerability within apache can expose the key.

I don't believe there is a way around it...