I'm facing some problems accessing by Claim Based to my web service.

On my App there's only Claim Based: windows auth is disabled and NTLM also. If I access to Sharepoint by web based interface, this recognise me as UserX and everything goes.

If I access by WS there are 2 scenarios:

  • Call by UserY (System Account) -> Everything goes well
  • Call by UserX (NO SA but SCAdmin) -> Object reference not set to an instance of an object

The code is very simple, gets only current user Login Name:

using (SPSite sito = new SPSite("https://to0wss2k10rey03:50000/sites/Test1"))
                using (SPWeb web = sito.OpenWeb())
                    string Username =  web.CurrentUser.LoginName;

The exception is raised when i try to get the CurrentUser, wich appears to be null..

  • Hmmm... where are you using the web services? This is plain 'ol server side OM code!? Do you run this in a console app, in a web part...? Which line do you get the null ref exception? Please provide us with more details... May 15, 2012 at 17:06

1 Answer 1


I'm quiet mystified by how it works with UserY, it should always fail.

When running with Claims without NTLM the only way to pass credentials is through a FedAuth cookie with your SharePoint STS SAML token. To get that token you have to call the SharePoint STS with a SAML token from your identityprovider (ADFS?). To get that token you have to call the identity provider with login info.

See Claims Proxy – A C# Library for Calling Claims Protected Web Services Connecting to SharePoint with Claims Authentication or the main blog about SharePoint with claims Share-n-dipity

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