[tor-bugs] #33541 [Applications/Tor Browser]: fingerprinting: zoom.min/maxPercent should be fixed at 100

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#33541: fingerprinting: zoom.min/maxPercent should be fixed at 100
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 Reporter:  cypherpunks                    |          Owner:  tbb-team
     Type:  defect                         |         Status:  new
 Priority:  Medium                         |      Milestone:
Component:  Applications/Tor Browser       |        Version:
 Severity:  Normal                         |     Resolution:
 Keywords:  tbb-fingerprinting-resolution  |  Actual Points:
Parent ID:                                 |         Points:
 Reviewer:                                 |        Sponsor:
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Comment (by tom):

 As I understand it, this ticket is saying "Hey, a user can manually choose
 to zoom the page, and when they do that, the resolution changes."  (And a
 bunch of other stuff changes too, like device pixel ratio and dpi and you
 can detect the zoom percentage.)

 > The ultimate solution, but I'm not entirely sure if it's feasible (or is
 but low priority and/or a lot of work), is that zoom could trigger
 letterboxing to re-calculate

 I don't understand what we would recalculate. When you zoom, the
 resolution of the browser stays the same, but from the website's
 perspective the resolution has decreased. The amount of information the
 website is (a) Original Resolution (b) Zoom Level.  Everything else is -
 AFAICT - a calculation of those two components, so trying to hide (B)
 would require hiding it as it's exposed everywhere (e.g. device pixel
 ratio)

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33541#comment:4>
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