Is there another way to import a root CA certificate in the JRE storage (cacerts file) of the plug-in rather then running the keytool.exe tool which comes with the JDK ? I can hardly believe that the Java plug-in does not look for root CA certificates in the Netscape 6 certificates storage (cert7db) or in the Windows certificates storage and that there would be no other to deploy a root CA than running keytool.exe on end-user systems !
