Calling from javascript a method which uses accesscontroller.dopriviledged

Question

Hello everybody!
I've a problem in accessing my pc resources from a signed applet when calling methods from Javascript.
If I try from start() or init() methods, I can do it, but as soon as I try from anoter method defined by myself, it throws this me an AccessControlException:access denied.
I googled and found that I should use this code:
KeyStore smartCardKeyStore= (KeyStore)
             AccessController.doPrivileged(
                       new PrivilegedExceptionAction() {
                         public Object run() throws KeyStoreException, NoSuchProviderException, NoSuchAlgorithmException, CertificateException, IOException {
                             KeyStore alfa;
                             alfa = KeyStore.getInstance("PKCS11",pkcs11Provider.getName());
                             alfa.load(null,null);//this is the point where it trhew the AccessControlException
                             return alfa;
                     );The problem is that with this code, I can't get it work with Firefox (which doesn't throw any exception, just won't work!) neither with IE, which throws this:
netscape.javascript.JSException: Nome sconosciuto.
java.lang.Exception: netscape.javascript.JSException: Nome sconosciuto.
     at sun.plugin.com.DispatchImpl.invokeImpl(Unknown Source)
     at sun.plugin.com.DispatchImpl$1.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at sun.plugin.com.DispatchImpl.invoke(Unknown Source)Please, help me! I'm in a big trouble, since I should finish my project asap and I am not able to pass this cumbersome obstacle...
Thank you in advance! :)

Answer 1

Hi! Don,
You cannot call methods which breach Security from Javascript. That is what SUN says.
But there is a hack, or a work around...
Declare a boolean Variable , say named buttonClicked.
Initailly keep its value false(default).
Write an inner class that extends a thread class whose RUN method will contain the following piece of Code:
public void run(){
    while(buttonClicked){
                 KeyStore smartCardKeyStore= (KeyStore)
             AccessController.doPrivileged(
                       new PrivilegedExceptionAction() {
                         public Object run() throws KeyStoreException, NoSuchProviderException, NoSuchAlgorithmException, CertificateException, IOException {
                             KeyStore alfa;
                             alfa = KeyStore.getInstance("PKCS11",pkcs11Provider.getName());
                             alfa.load(null,null);//this is the point where it trhew the AccessControlException
                             return alfa;
}You start the Thread inner class in your init method.
So, its RUN method will continuously be waiting to go into the while loop.
And in your start method you will set the +"buttonClicked"+ variable to true upon a Javascript onclick event of a button.
So, the moment you click a button, you only set the buttonClciked variable to true in your start method--------
This does, in no way breach security. So no exception is thrown.. But the code which breaches security is initiated by another thread other than that spawned the Applet; so the browser does not care anything about its privileges. It just lets the execution of the code.
I hope it works for you; be in contact, if it doesn't.
Thanks and Regards,
Samba