Excellent article, and a sugestion [LWN.net]

Excellent article, and a sugestion

Posted Mar 7, 2012 22:12 UTC (Wed) by daniels (subscriber, #16193)
In reply to: Excellent article, and a sugestion by dgm
Parent article: The life story of the XInput multitouch extension

The problem is that this would preclude any global gestures from taking place anywhere inside your keypad at all, which would be really jarring. If you're allowing untrusted clients to connect and do arbitrary things to your display, then it's just as easy for one of them to pretend to be your keyboard/numpad and sniff your password. Or just cut out the middle man and impersonate your browser.

So what you've suggested doesn't really help in any meaningful way, but imposes a significant usability cost.

(Log in to post comments)

Excellent article, and a sugestion

Posted Mar 7, 2012 22:27 UTC (Wed) by josh (subscriber, #17465) [Link]

Whenever the onscreen keyboard gets a gesture it doesn't want to handle, it could cause that gesture to get forwarded to the rest of the system; only touch inputs that actually typed on the keyboard would get hidden from the rest of the system.

Excellent article, and a sugestion

Posted Mar 7, 2012 22:38 UTC (Wed) by daniels (subscriber, #16193) [Link]

This inverts the order from the rest of the system, where the window manager makes the decision on whether or not to forward to the event to the app. This is particularly problematic for cases where, for instance, you have a three-finger swipe to bring up an Exposé-style app overview. Now, if you do a three-finger swipe with two fingers over your browser and one over your keypad, the keypad has swallowed the gesture as regular movement/drag, and you've given the browser a two-finger scroll.

And even all this still doesn't solve any of the security problems. The long and short of it is that if you give untrusted clients complete access to your X server, then you cannot -- cannot -- win in any way.

Excellent article, and a sugestion

Posted Jun 7, 2012 11:07 UTC (Thu) by cheako (guest, #81350) [Link]

Life is hard, it's over when you give up. I like little nuggets like this, they really say something instead of me trying to convey some technical theory.

I don't believe any system is totally secure. I know that a lock on a door can be picked easily. This doesn't stop me from locking my front door every time I leave. Just because something is hard, just because something is challenging and most importantly when something is impossible. Are you just going to give up and let the rest of your life amount to nothing?

That's fine by me, but don't take others with you when you go. If you'r going to write the application equivalent of a poisoned punch(even if it's only fatal vary rarely and even then only for stupid ppl), do go giving it out at a party... That's not cool!

Excellent article, and a sugestion

Posted Mar 8, 2012 7:58 UTC (Thu) by michaeljt (subscriber, #39183) [Link]

daniels wrote:
> The problem is that this would preclude any global gestures from taking place anywhere inside your keypad at all, which would be really jarring.

Daniel, sorry for the really stupid question (never used multi-touch) but what is an example of a global gesture in a touch screen/multi-application context?