Student Introduction and Possible Proposal

[Moritz Lenz]

Hello Justin,

welcome to the Parrot project, and thanks for your email.

Am 02.04.2012 18:47, schrieb Justin L. Harper:
> After further
> talks with @whiteknight and  @benabik I headed into the direction of
> proposing the Security Sandboxing project. It is a project that can be
> extended or shortened depending on time and possible constraints.

As a developer of a downstream project (Rakudo), I'd be very interested 
to see such a project implemented.

>  The
> over all goal of the project is to develop an interface that allows
> the parent to set permissions on the child but not allow the child to
> alter its own permissions.

There's no reason the child wouldn't be allowed to tighten its own 
security -- it just can't loosen it. In fact that's the model that UNIX 
systems use for things such as process priority (the "nice" value)

> If anyone has possible ideas
> or suggestions towards this project I am open to any and all ideas.

PDD 18 [1] describes the high-level goals and mechanism. A GSoC project 
surely isn't enough to implement all of it, but having *something* would 
be a good start.

Another good source for inspiration is prior art in linux. There is the 
ptrace mechanism for intercepting system calls [2], and selinux for 
capability-based access control [3].

I haven't spent too much time thinking about the security system, so 
take the following with a grain of salt.
I think the best approach to getting results fast is to implement 
something like ptrace, where possibly dangerous operations (memory 
allocations, IO, ...) trigger a callback, and that callback can then 
allow or forbid the operation. For performance reasons it might make 
sense to allow or forbid some operations right away without any 
callback, but I guess that's only a second step.

Once such a system is in place, you can write a capability-based system 
on top of that.

[1] 
http://docs.parrot.org/parrot/devel/html/docs/pdds/pdd18_security.pod.html
[2] http://www.linuxjournal.com/article/6100
[3] https://en.wikipedia.org/wiki/Security-Enhanced_Linux

> I
> look forward to proposing and hopefully working on this project. Have
> a great day!

And I look forward to see the actual project proposal and the code :-).

Remember that the application deadline is the upcoming Friday, so don't 
waste any time.

Cheers,
Moritz