Java Reference
In-Depth Information
This compliant solution illustrates the use of an
AccessControlContext
in the two-
argument form of
doPrivileged()
.
class ACC {
private static class RestrictedAccessControlContext {
private static final AccessControlContext INSTANCE;
static {
INSTANCE =
new AccessControlContext(
new ProtectionDomain[] {
new ProtectionDomain(null, null) // No permissions
});
}
}
private static void evalScript(final String firstName)
throws ScriptException {
ScriptEngineManager manager = new ScriptEngineManager();
final ScriptEngine engine =
manager.getEngineByName("javascript");
// Restrict permission using the two-argument
// form of doPrivileged()
try {
AccessController.doPrivileged(
new PrivilegedExceptionAction<Object>() {
public Object run() throws ScriptException {
engine.eval("print('" + firstName + "')");
return null;
}
},
// From nested class
RestrictedAccessControlContext.INSTANCE);
} catch (PrivilegedActionException pae) {
// Handle error
}
}
}
This approach can be combined with whitelisting for additional security.
