Java support - install a SecurityManager from JRuby

luislavena · March 9, 2011, 12:03pm

Not sure if I’m doing things 100% right.
I tried to extend a java class java.lang.SecurityManager and then
install it for the JVM (System.setSecurityManager) - I’ve expected for
this to work

gist.github.com

https://gist.github.com/kares/862023

jruby_set_security_manager.rb

require 'java'

class JRubySecurityManager < java.lang.SecurityManager
  def checkPermission( perm ) 
    puts perm.inspect 
  end
end

java.lang.System.setSecurityManager( JRubySecurityManager.new )

stack_trace.txt

# from 1.6.0.RC3 (it's about the same on 1.5.6)
JavaClass.java:835:in `installClassFields': java.lang.NullPointerException
	from JavaClass.java:702:in `setupProxy'
	from Java.java:524:in `createProxyClass'
	from Java.java:453:in `getProxyClass'
	from Java.java:362:in `getInstance'
	from JavaUtil.java:160:in `convertJavaToUsableRubyObject'
	from JavaProxyConstructor.java:220:in `invoke'
	from null:-1:in `checkPermission'
	from SecurityManager.java:871:in `checkRead'

This file has been truncated. show original

but it didn’t - same result for 1.5.6 as well as 1.6.0.RC3 !

Is this a JRuby bug or is the java support not that mature or is it just
me doing something wrong ?

karol_b · March 9, 2011, 2:27pm

Not really an answer, but I notice that it isn’t even managing to invoke
setSecurityManager.

What line of that script is it failing on - Is it the definition of that
JRubySecurityManager class, or when you invoke .new?

On Wed, 2011-03-09 at 12:03 +0100, Karol B. wrote:

me doing something wrong ?

–
Nick G.
Developer @ Media Service Provider
+44 207 729 4797

karol_b · March 9, 2011, 3:51pm

right maybe it’s not clear at first :

the JRubySecurityManager.new is OK

what fails is the java.lang.System.setSecurityManager with the new
“jruby” manager.

if I understand correctly JRuby attempts to create a proxy for the first
checkPermission call (triggered by SecurityManager.checkExit) -
while doing so another security manager check is triggered (checkRead)
and it fails …