Apache ServerName, handlerURL, and Reverse Proxy

[Peter Schober]

* Martin Haase <martin.haase at daasi.de> [2013-01-09 16:51]:
> we have a reverse proxy scenario with SP 2.5.1. For several reasons, we 
> cannot set Apache's ServerName to the proxy's name, but must leave it on 
> the target's name.

How about not setting ServerName on the backend ("target") at all?
Probably opens up vectors for circumventing vhost based ACLs?

I also know of a reverse proxy (which also terminates SSL) scenario by
an institution from our constituency where the proxy would set custom
http headers for the request (request_uri, scheme, hostname, port) as
seen by the proxy and have local code in httpd and mod_shib so that
the values set by the proxy are used for processing.
-peter