Sample C++ ISAPI filter and extension for debugging issues with filters related to other extensions (or ASP.net) eating POST requests.
This is a sample IIS filter & extension that prints out a custom header and echos the post back. It is also a simple example of creating a combo filter & extension for IIS 7.0, 7.5, 8.0, 8.5.
In order to use the UMFilter.dll ISAPI filter+extension you need to install the Visual C++ 2017 redistributable.
This UMFilter.dll was built using Visual Studio 2017 (Community Edition) using the following settings:
- Configuration: 64bit Release build
- Target Platform: Windows 10
- Windows SDK Version: 10.0.16299.0
- Platform Toolset: Visual Studio 2017 (v141)
- Use of MFC: Use Standard Windows Libraries
- Common Language Runtime Support: No Common Language Runtime Support
Using a utility that can make POST http requests, like curl, you need to POST data to a url that matches the ISAPI script mapping you setup.
An example would be if you are testing your local IIS that has mapped the dll to *.sso then you would POST "param1=test1¶m2=test2" to "http://localhost/Shibboleth.sso"
using curl: curl -v -d "param1=test¶m2=test2" "http://localhost/Shibboleth.sso"
The successful response back would be:
<html><body><pre>param1=test1¶m2=test2</pre></body></html> showing that all your POSTed data is printed in the pre element tag, you will also see the custom header in the response headers.