IIS removes If-None-Match and If-Modified-Since headers

Question

I have an ASHX handler or an ASPX page (the problem happens in both cases). The web client sends a request containing If-None-Match and/or If-Modified-Since headers but context.Request.Headers.Get("If-None-Match") or context.Request.Headers.Get("If-Modified-Since") is null in the handler.

The same script works in my local development machine but it doesn't work in the online machine (both are running IIS7 on Win 2008, .NET 3.5)

Answer 1

Hello, You may use 3rd-party module to create duplicates of those headers before apsx page is executed. For example with Helicon Ape (http://www.helicontech.com/ape) these rules may do the trick:

SetEnvIf If-None-Match (.*) e-if-none-match=$1
SetEnvIf If-Modified-Since (.*) e-if-modified-since=$1

RequestHeader set My-If-None-Match %{e-if-none-match}e
RequestHeader set My-If-Modified-Since %{e-if-modified-since}e

Basically they get the headers and set the new ones with My- prefix. This will work only if IIS doesn’t remove headers before Ape.