[libvirt] Do different Virgil3D users running have the same CANVAS fingerprint?

bancfc at openmailbox.org bancfc at openmailbox.org
Wed Jan 11 04:34:45 UTC 2017


ACK :)

On 2017-01-09 11:17, Martin Kletzander wrote:
> On Sun, Jan 08, 2017 at 07:17:07PM +0100, bancfc at openmailbox.org wrote:
>> On 2016-12-27 04:05, bancfc at openmailbox.org wrote:
>>> Background:
>>> Canvas fingerprinting is a technique to track users based on their
>>> GPUs. https://en.wikipedia.org/wiki/Canvas_fingerprinting
>>> 
>>> Someone did some testing and the good news is the fingerprint is
>>> common for all users of the same OS across all KVM users because it
>>> presents the same virtual GPU/drivers for everybody.
>>> 
>>> What I need your help to find out is whether this holds for Virgil3D
>>> users that enable graphics acceleration. (I am running on Debian and
>>> the libvirt version in the repos is too old to have this included 
>>> also
> 
> $ ./configure && make && make install # O:-)
> 
>>> I don't have multiple machines)
> 
> Oh, not even nested VMs won't hep here :(
> 
>>> 
>>> 
>>> To test this you need:
>>> 
>>> To run plain FireFox on a virtualized distro (with GL acceleration
>>> enabled in libvirt) of your choice and visit
>>> https://browserleaks.com/canvas . Then repeat the same steps with 
>>> that
>>> same distro (in a VM) on another physical machine and compare values.
>>> 
>>> A good result is if you see the same numbers for both machines. That
>>> means the virtual device  fingerprint is uniform for all virtual
>>> users.
>> 
>> Bumping. I realized I post this in holiday season when it was easily
>> missed.
>> 
> 
> Not only were even patches discussed during that time, but people will
> catch up on things after the break, don't worry.
> 
>> Since CANVAS is about graphics drivers version the question can be
>> simplified: Is the virtio-gpu driver version uniform across KVM
>> versions?
>> 
> 
> I think the drivers and versions will not be the same nor different 
> *all
> the time*.  Based on what the method says, the main difference is done
> by font selection, hinting and antialiasing settings.  I don't think
> that will be dependent on the graphics hardware.  Although the hardware
> description might look the same.  The details about that should 
> probably
> be asked somewhere else than libvirt, e.g. whoever does virglrenderer 
> or
> qemu or...
> 
> I don't have another machine handy and my graphics guests are borked 
> for
> some reason (and I spent a lot of time trying to fix those already), so
> I won't help much there.  I tried it with some live media, but then
> realized it's not going to help.  I'd have to try the same VM (not only
> distro), I guess.
> 
>> 
>> --
>> libvir-list mailing list
>> libvir-list at redhat.com
>> https://www.redhat.com/mailman/listinfo/libvir-list




More information about the libvir-list mailing list