Provide Fault Method in WCF receives FaultException with no details

Question

I have implemented an IErrorHandler for my service witch needs to return 403 instead o 400 in case of wrong Authorization.
This is how my ProvideFault method looks like:

public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
    if (((FaultException)error).Code.SubCode.Name == "FailedAuthentication")
    {
        WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.Forbidden;
        WebOperationContext.Current.OutgoingResponse.StatusDescription =
            "StatusCode is forced to change in order to have the correct response on authentication.";
    }
}

I wonder if there is any way to write a more nicer check for the error and its status code, or how to get an authorization exception not a FaultException witch is more general?. I don't find it nice to check after the FailedAuthentication string, and in fact its authorization not authentication...

Answer 1

If your are using C# 6.0 and above, you can use Exception Filters. The example is:

public string Example() 
{
   try
   {
      /* Method Logic */
      return string.Empty;
   }
   catch (System.Net.Http.HttpRequestException e) when (e.Message.Contains("400"))
   {
      return "unauthorized";
   }
}

In your case:

public string Example() 
{
   try
   {
      /* Method Logic */
      return string.Empty;
   }
   catch (System.Net.Http.HttpRequestException e) when (e.Message.Contains("400"))
   {
      ProvideFault(e, "", e.Message);
   }
}

public void ProvideFault(System.Net.Http.HttpRequestException error, MessageVersion version, ref Message fault)
{
   /* your logic according to your needs. */
}