ShibRequestSetting and Apache Environment Variables

[Andrew D.]

Hey,

I'm attempting to support two identity providers.  I would like to
provide "friendly names" for the end users, e.g.,
https://sp.example.org/secure/name1 and
https://sp.example.org/secure/name2.

I'm trying to set an environment variable using mod_rewrite, but I'm
not sure if I will be able to use the variable in the Directory
directive.  Here is what I have so far:

RewriteEngine On
RewriteRule ^/secure/name1(.*) /secure$1
[E=ENTITY_ID:https://idp1.example.org/idp/shibboleth,L]
RewriteRule ^/secure/name2(.*) /secure$1
[E=ENTITY_ID:https://idp2.example.org/idp/shibboleth,L]
<Directory "/srv/http/secure">
    AuthType shibboleth
    ShibRequestSetting requireSession On
    ShibRequestSetting entityID env=ENTITY_ID
    Require valid-user
    ShibUseHeaders On
</Directory>

The part I'm having trouble with is figuring out the syntax for
"ShibRequestSetting entityID env=ENTITY_ID".  Is what I'm attempting
even possible?  If so, how and is it the correct solution?

Thanks!