[Dev] Cynara

Patrick Ohly patrick.ohly at intel.com
Thu Apr 10 18:23:55 GMT 2014


On Thu, 2014-04-10 at 16:06 +0000, Schaufler, Casey wrote:
> > -----Original Message-----
> > From: Patrick Ohly [mailto:patrick.ohly at intel.com]
> > Sent: Thursday, April 10, 2014 2:05 AM
> > To: Schaufler, Casey
> > Cc: José Bollo; dev at lists.tizen.org; Lukasz Wojciechowski
> > Subject: Re: [Dev] Cynara
> > 
> > On Wed, 2014-04-09 at 16:34 +0000, Schaufler, Casey wrote:
> > > > On Wed, 2014-04-09 at 15:13 +0200, José Bollo wrote:
> > > > > On mer, 2014-04-09 at 14:35 +0200, Patrick Ohly wrote:
> > > > > You are right: apps not launched, not receiving the treatment have
> > > > > full accesses. But to my eyes it is not a problem because:
> > > > >  - Tizen enforces the use of launcher (for security) so what are the
> > > > > applications that aren't launched?
> > > >
> > > > Which Tizen profile do you refer to here?
> > > >
> > > > In Tizen IVI there are several user processes which do not get spawned
> > by
> > > > the launcher and thus have access to more data than they really need.
> > >
> > > Those are mostly services (weston, murphyd) and basic
> > > UI applications (weekeyboard). Everything on Tizen (true
> > > for Android, too BTW) has access to more data than it needs.
> > > The question is whether it has access to data that matters.
> > > Who cares if it can read /etc/tizen-release?
> > 
> > I guess it depends on the data and the goals. I'd certainly would be
> > more comfortable with a Tizen device where Weston, murphyd and
> > weekeyboard can't read or (worse) write my PIM data.
> 
> What is "PIM data"?

Personal information management. In my definition that's primarily
contacts, events, tasks and notes. Sometimes email is also included.

> You are already trusting weekeyboard with your passwords
> and weston with everything you display. If no one is making sure
> that these programs are worthy of trust we have much bigger
> problems than murphyd getting an accidental peek at your
> "PIM data".

Weston was a bad example and digressed (as far as I am concerned - I'm
sure Jussi disagrees ;-) into (admittedly interesting) discussion of how
to communicate reliably with components in the system.

My main concern is about the other, less privileged processes that
currently get started such that they can access everything although they
don't need to. If Tizen is going to treat system apps (for example: the
Lemolo dialer in IVI) like third-party apps from an app store, then that
concern gets addressed sufficiently well. If not, then I think we should
reconsider that approach.

Saying "these are trusted apps, we don't need to control them" doesn't
fly for me. Shit happens, so the less damage these apps can do when it
happens the better. This doesn't even have to be an exploit.
Accidentally erasing or trashing an important file would also be bad.

But of course that doesn't come for free, so I can accept the argument
"these are trusted apps, we've done as much as we could in our limited
time to make them reliable, further effort is better spent elsewhere".

> > Whether it's worth investing extra effort is up to the people defining
> > the product and its requirements.
> 
> We have to live within the security budget. That means we can't
> fix everything that's broken, we can't replace everything that's
> hopelessly broken and we can't wrap everything with a protective
> layer of magic that prevents good programs from doing bad things.
> We can take steps, and isolating user installed applications is much
> more important than anything else. Assuring that weekeyboard
> and murphyd have absolutely minimal mutual access is just not
> cost effective.

Fair enough.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.





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