How show CLIENT-CERT Realm

[Antony GUILLOTEAU]

I'm able to show the login window of a basic realm with following code :
   response.setHeader("WWW-Authenticate", "BASIC realm=\"myName\"");
   response.sendError(HttpServletResponse.SC_UNAUTHORIZED);

Now I wish to show the window like CLIENT-CERT : when all realm parameters are 
set in the web.xml that 's work fine. But I want to do the same thing 
programmaticly with response.sendError(HttpServletResponse.SC_UNAUTHORIZED).

I think it is done in the tomcat code ... but where ?

Thanks