// When this method runs, the caller must be an authenticated user 
// and the ServiceSecurityContext is not a null instance. 
public double Add(double n1, double n2)
{
    // Write data from the ServiceSecurityContext to a file using the StreamWriter class.
    using (StreamWriter sw = new StreamWriter(@"c:\ServiceSecurityContextInfo.txt"))
    {
        // Write the primary identity and Windows identity. The primary identity is derived from 
        // 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);

        // Write the claimsets in the authorization context. By default, there is only one claimset
        // provided by the system. 
        foreach (ClaimSet claimset in ServiceSecurityContext.Current.AuthorizationContext.ClaimSets)
        {
            foreach (Claim 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}, Resource: {1} Right: {2}",
                    claim.ClaimType,
                    claim.Resource.ToString(),
                    claim.Right);
                sw.WriteLine();
            }
        }
    }
    return n1 + n2;
}

public class MyServiceAuthorizationManager : ServiceAuthorizationManager
{
    protected override bool CheckAccessCore(OperationContext operationContext)
    {                
        // Extract the action URI from the OperationContext. Match this against the claims
        // in the AuthorizationContext.
        string action = operationContext.RequestContext.RequestMessage.Headers.Action;
        Console.WriteLine("action: {0}", action);

        // Iterate through the various claimsets in the AuthorizationContext.
        foreach(ClaimSet cs in operationContext.ServiceSecurityContext.AuthorizationContext.ClaimSets)
        {
            // Examine only those claim sets issued by System.
            if (cs.Issuer == ClaimSet.System)
            {
                // Iterate through claims of type "http://example.org/claims/allowedoperation".
                foreach (Claim c in cs.FindClaims("http://example.org/claims/allowedoperation", 
                    Rights.PossessProperty))
                {
                    // Write the Claim resource to the console.
                    Console.WriteLine("resource: {0}", c.Resource.ToString());

                    // If the Claim resource matches the action URI then return true to allow access.
                    if (action == c.Resource.ToString())
                        return true;
                }
            }
        }

        // If this point is reached, return false to deny access.
         return false;                 
    }
}