From: Gary Wright <gwtmp01@...>
Date: 2011-12-19T09:01:07+09:00
Subject: Re: Ruby, SAFE, method interception, and plugins


On Dec 18, 2011, at 3:16 AM, Garthy D wrote:
> As some app users might run plugins other app users have written, being able to limit the damage they can cause is also important. I'm not fussed if certain operations could cause a denial of service (eg. just run "while true; end"), as the environment would be such that the affected user could just kill the process and disable the plugin- it's not a web server. I *would* be fussed though if the plugin was able to read and write files to the system directly, or cause lasting damage outside of the application itself.

I'm not sure that I would want to rely on any language enforced constraints for executing 'hostile' code within the same address space as my main application.  I think a better solution is to run the foreign code (that sounds nicer) in an external process or even on a completely separate system and then use some sort of communication scheme to interact with the foreign code. If the communication scheme is well defined it also means that the plugin doesn't have to even be in Ruby.

If you want to run it on the same system but in a different process you can arrange for the process to be 'locked down' in a sandbox or other restricted environment.  The specifics on how to do this are going to be very dependent on your production environment but perhaps someone will pipe up with some specific suggestions if you tell us about your environment.

Gary Wright