Passing Shibboleth SP Headers to Tomcat on IIS 7 with Tomcat Connector

[Gary Gwin]

I have a Shibboleth SP IIS 7 configuration working with multiple 
applications in the same "Default Web Site" vhost using <RequestMaps> 
that match on patterns like this:

<PathRegex regex="idp/1" applicationId="idp1" authType="shibboleth" 
requireSession="true"/>
<PathRegex regex="idp/2" applicationId="idp2" authType="shibboleth" 
requireSession="true"/>

Shibboleth SP only populates headers when the path above is matched, 
which makes sense. If I map the same path to the Tomcat Connector, then 
Shibboleth SP appears to be bypassed and the request is sent to Tomcat 
directly. I've tried various orderings of the respective ISAPI filters 
with no luck.

Is there a known way to configure Shibboleth SP with IIS 7, the Tomcat 
Connector and Tomcat such that the Shibboleth headers are sent to Tomcat?

Or, is there an alternative way for a Servlet in Tomcat to get a handle 
to such Shibboleth information?

Cheers,

Gary