I am trying to use an embedded Excel work book within a SharePoint site. This workbook connects to SSAS using Integrated Security. It works correctly when I log in to SharePoint using windows authentication, but when logging using claims (from our custom claims provider which passes a valid UPN claim), the error "The data connection uses Windows Authentication and user credentials could not be delegated" occurs, and the following is found in the log.
Verbose CredentialsProvider.GetCredentials: Getting credentials for external source: DBNAME, with CredentialsMethod Integrated Verbose MossHost.TryGetWindowsIdentity: Current identity is ClaimsIdentity. We need to get a WindowsIdentity. Medium MossHost.TryGetWindowsIdentity: Cannot get WindowsIdentity: identity is a Claims identity, but does not have a Windows token. Medium CredentialsProvider.GetCredentials: Failed to get WindowsIdentity. Warning Credential delegation failed because Excel Services Application was unable to obtain a Windows Identity. [Session: 1.V22.32rno3Y4NdyzpSirO8TPl590.5.en-US5.en-US73.+0000#0000-10-00-05T02:00:00:0000#+0000#0000-03-00-05T01:00:00:0000#-006036.fa715221-d2cc-4848-a14d-8f5db6fb19911.N User: email@example.com]
Should this work at all? I thought that Excel Services could use c2wts to obtain a Windows Identity from my UPN claim. I need to use Integrated Security on the workbook because the SSAS behind it has dynamic security based on this, but is there an alternative? (I know that PerformancePoint you can pass the username as custom data within the connection string)