Interceptor, HttpModule, WSE

[oliver.wulff]

I've developed a framework for ASP.NET with a custom authentication module
(HttpModule). This module is already working. This framework should also
delegate the authenticated principal automatically therefore the
application developer doesn't have to worry about principal delegation.
I'm looking for an interceptor mechanism to delegate the principal. I
haven't found an outbound interceptor in ASP.NET. I want to set either the
authorization header or set a custom http header. The outbound filter of
WSE has only access to the soap message. The HttpModule is the interceptor
mechanism for inbound requests but is there no way to intercept the
outgoing http communication for webservices?

Hope somebody can help me
Oliver