Overview
I want to be able to modify request parameters and content to 3rd party web services (ArcGIS Server). This will be used to create a securit
As Chris McKeown states, this is not really the best technique for filtering unless you promise to not modify the size of the data. For completeness of this answer, I've posted a sample project which demonstrates how to handle filtering the request and the response using the buffered technique if you are interested.
https://github.com/snives/HttpModuleRewrite
Also for questions relating to troubleshooting HttpModules for filtering this post was also very helpful Is it possible to modify the content of HttpRequest POST in an IIS HttpModule?