Java plugin:security exception even after selecting "grant this session"

Question

I have made a signed jar with a class in it which tries to access system properties "System.getProperties"
Now i am instantiating this class from an applet which is unsigned.
When i try to view the applet th' java plugin it shows the window asking for the permissions but when i say "grant this session " or grant always" it gives secuity exception.
I would like to know that is it possible to access the class which is signed from an unsigned applet.
I have used netscape signing tools 1.3 for making a test certificate and putting it in cacerts store of java plugin.
And signing the jar file with this certificate.
Kindly help.
Thanks in advance.

Answer 1

As far as I understand the Java security model, by default, the AccessController gives your class's method call the lowest common security permissions of all classes invoked. In order for a class in a more trusted/priveleged security domain (i.e. the signed jar) to be used by your unsigned applet you would have to use the doPriveleged() method of the AccessController class. See:
http://java.sun.com/j2se/1.3/docs/api/java/security/AccessController.html
Hope that's of use.
I have made a signed jar with a class in it which
tries to access system properties
"System.getProperties"
Now i am instantiating this class from an applet which
is unsigned.
When i try to view the applet th' java plugin it shows
the window asking for the permissions but when i say
"grant this session " or grant always" it gives
secuity exception.
I would like to know that is it possible to access the
class which is signed from an unsigned applet.
I have used netscape signing tools 1.3 for making a
test certificate and putting it in cacerts store of
java plugin.
And signing the jar file with this certificate.
Kindly help.
Thanks in advance.