' Run this method from within a method protected by the PrincipalPermissionAttribute
' to see the security context data, including the primary identity.
Public Sub WriteServiceSecurityContextData(ByVal fileName As String)
    Dim sw As New StreamWriter(fileName)
    Try
        ' Write the primary identity and Windows identity. The primary identity is derived from the
        ' the credentials used to authenticate the user. The Windows identity may be a null string.
        sw.WriteLine("PrimaryIdentity: {0}", ServiceSecurityContext.Current.PrimaryIdentity.Name)
        sw.WriteLine("WindowsIdentity: {0}", ServiceSecurityContext.Current.WindowsIdentity.Name)
        sw.WriteLine()
        ' Write the claimsets in the authorization context. By default, there is only one claimset
        ' provided by the system. 
        Dim claimset As ClaimSet
        For Each claimset In ServiceSecurityContext.Current.AuthorizationContext.ClaimSets
            Dim claim As Claim
            For Each claim In claimset
                ' Write out each claim type, claim value, and the right. There are two
                ' possible values for the right: "identity" and "possessproperty". 
                sw.WriteLine("Claim Type = {0}", claim.ClaimType)
                sw.WriteLine(vbTab + " Resource = {0}", claim.Resource.ToString())
                sw.WriteLine(vbTab + " Right = {0}", claim.Right)
            Next claim
        Next claimset
    Finally
        sw.Dispose()
    End Try

End Sub