File proxy handler in IIS 7

Question

I have a file proxy IHttpHandler to ensure authentication and to log requests. It works fine on the development server and IIS 6. In IIS 7, I have two problems:

1. Microsoft Office (Word, Excel...) sends WebDAV requests with OPTION and PROPFIND verbs. ASP.NET throws an exception since it doesn't support them. Is there any way to disable these verbs at the IIS level so that it never reaches ASP.NET? I'm guessing it would be returning a 405 Method Not Allowed error (http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#4xx_Client_Error).

2. IIS 7 turns on chunked encoding. In that case the Content-Length header is not valid and apparently IIS 7 removes it: http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.4.4. However, it also removes the Content-Type header, causing the files to show up as text in the browser. So how can I stop IIS 7 from removing Content-Type, OR how do I turn off chunked encoding for this one page? Below are the response headers for you to compare.

Development server response:

HTTP/1.1 200 OK
Server: ASP.NET Development Server/9.0.0.0
Date: Thu, 23 Dec 2010 17:57:09 GMT
X-AspNet-Version: 2.0.50727
Content-Length: 68096
Content-Disposition: inline; filename=test.doc
Cache-Control: private
Last-Modified: Thu, 23 Dec 2010 09:14:18 GMT
Content-Type: application/msword
Connection: Close

IIS 7 response:

HTTP/1.1 200 OK
Cache-Control: private
Transfer-Encoding: chunked
Last-Modified: Thu, 23 Dec 2010 09:30:31 GMT
Server: Microsoft-IIS/7.5
Content-Disposition: inline; filename=test.doc
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
Date: Thu, 23 Dec 2010 17:57:59 GMT

Answer 1

My question on chunked encoding was inaccurate. I had made one small change on my development machine: I added Content-Length. On the development machine it didn't make a difference--it always worked. In IIS 7, adding Content-Length actually disabled chunked encoding and everything worked as expected.

For the WebDAV requests, IIS 7 doesn't send them through to ASP.NET so we're fine. The development server does, however. I saw a suggestion to add the DefaultHttpHandler to handle them, but on the development server that means the raw aspx page is served.