Granting different permissions to different codebases : policy file problem

Question

Hi all. I'm having a bit of a problem with policy files and granting different persmissions to different codebases. What I have at the moment is a server app that copies a class file from the client to a specified directory on the server, and then dynamically loads and runs that class. This all works fine, but obviously as user submitted code is going to be run on the server I want to restrict what they are allowed to do. My app is going to be bundled up in a single jar file, and the directory that the client code is being copied to a subdirectory of the app installtion (not that this should make much difference). What i want to do is grant all permissions to my code in the jar file and resrict the permssions granted to code in the strategies directory. I assumed i would just be able to do this using my own policy file, but at the moment i'm not having much luck.
Directory structure:
c:/project/code/
|
|-labyrinth.jar
|-strategies/
Contents of labyrinth.policy:
grant codeBase "file:../code/labyrinth.jar" {
permission java.security.AllPermission;
Command line arguments:
java -Djava.security.manager -Djava.security.policy==./labyrinth.policy -classpath .;./labyrinth.jar;./strategies/;%CLASSPATH%; labyrinth.LabyrinthServer
I've tried specifiying the absolute path to the jar file in the policy file as well as the relative path, i've tried including -Xbootclasspath/a and appending the jar file. All I seem to be able to manage though is either granting all permissions system wide, including the strategies dir, or none and getting security exceptions within my code. Anyone tried doing anything similair or got any idea where I might be going wrong? Any help would be appreciated as its really starting to doing my head in.
TIA. Matt.

Answer 1

Did you try putting a slash at the beginning of your "file" specification? e.g., instead of saying
grant codeBase "file:../code/labyrinth.jar" {
permission java.security.AllPermission;
say
grant codeBase "file:/../code/labyrinth.jar" {
permission java.security.AllPermission;
Hope this helps.