Password required? The remote server returned an error: (401) Unauthorized

Question

I'm trying reference a sharepoint list item in my aspx page using the Sharepoint Client Object Model. I have been granted 'Full Control' privileges on this list. The problem is that I can only complete the request when I set the ClientContext.Credentials explicitly with my password hard-coded into the page. Obviously I don't want visitors to my site to have the access to things based on my credentials.

This gets it to work but does not meet the project requirements:

ClientContext cc = new ClientContext("http://sharepoint.site.com/sitename");
cc.Credentials = new NetworkCredential("username", "password", "domain");

I have set in the web.config and seems to be working fine. When I check WindowsIdentity.GetCurrent().Name it shows my correct "domain\username" information, which I think should mean my credentials are valid. Why then, is SharePoint rejecting the cc.ExecuteQuery(); with a "System.Net.WebException The remote server returned an error: (401) Unauthorized."?

I can put a textbox on the screen that lets the user enter their password to used to create a NetworkCredential object, but I can tell you right now the customer (my Boss) is not going to be happy with this and is going tell me he wants me to find a work around.

Edit: The sharepoint site is hosted on a different site, but within the same company intranet.

Answer 1

Are you using kerberos, ntlm, forms or claims? My guess is you are using NTLM and running into the NTLM double hop "issue".

http://blogs.msdn.com/b/besidethepoint/archive/2010/05/09/double-hop-authentication-why-ntlm-fails-and-kerberos-works.aspx

The easiest next step is probably to change your site over to Kerberos. I have a blog article where I outlined some resources that help when setting up kerberos in SharePoint.

http://steve.thelineberrys.com/resources-for-setting-up-kerberos-authentication-in-sharepoint/

Answer 2

Have you tried using DefaultCredentials instead, to pick up the identity of the current user?

Additionally: is this aspx running within your SharePoint site? If so, why are you using the Client Object Model? Just use the server OM. Far easier and much less hassle.