have a client that issues an HTTP PUT to upload a file to a SharePoint server. This server requires authentication (NTLM or Negotiate). The client includes an "Expect: 100-Continue" header in the PUT request.
When I PUT the file to SharePoint2010 (IIS 7.5), the server immediately responds with a 401 error as soon as it receives the header. This allow the client to begin the authentication process without unnecessarily uploading the entire file.
When I PUT the file to SharePoint2013 (IIS 8.0), the server immediately responds with a 100-Continue. However, once the client has uploaded the file in the body of the request, it replies with a 401. This means that the client has uploaded the entire file just to receive an authentication error. The server should have been able to respond with the 401 prior to the client uploading all of the data, as IIS 7.5 does.
Is this change in behavior inherent in IIS8 and/or SharePoint 2013? Is there a configuration option that controls this? Is there something I can tweak in the header to change the server's behavior?