[tor-bugs] #15473 [Tor Browser]: JS Date object reveals OS type (TBB specific)

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#15473: JS Date object reveals OS type (TBB specific)
---------------------------------+-----------------------------------
     Reporter:  arthuredelstein  |      Owner:  tbb-team
         Type:  defect           |     Status:  new
     Priority:  normal           |  Milestone:
    Component:  Tor Browser      |    Version:
   Resolution:                   |   Keywords:  tbb-fingerprinting-os
Actual Points:                   |  Parent ID:
       Points:                   |
---------------------------------+-----------------------------------

Old description:

> Calls like new Date().toLocaleString() produce different Date formatting,
> depending on the platform.
>
> Example from gk:
>
> {{{
> Mac: Wed Mar 25 ...
> Win: Wednesday, March 25 ...
> Linux: 3/25 ...
> }}}

New description:

 Calls like new Date().toLocaleFormat() produce different Date formatting,
 depending on the platform.

 Example from mcs:

 > Ubuntu:
 > {{{Array [ "Thu 26 Mar 2015 03:43:35 PM EDT", "3/26/2015, 3:43:35 PM"
 ]}}}
 > OSX:
 > {{{Array [ "Thu Mar 26 15:38:55 2015", "3/26/2015, 3:38:55 PM" ]}}}
 > Windows 7:
 > {{{Array [ "Thursday, March 26, 2015 3:45:01 PM", "3/26/2015, 3:45:01
 PM" ]}}}

--

Comment (by arthuredelstein):

 Replying to [comment:5 mcs]:
 > Replying to [comment:4 arthuredelstein]:
 > > I just tested in standard Firefox (presumably using the US English
 locale) by entering:
 > > `[new Date().toLocaleFormat(), new Date().toLocaleString()]`
 > > ...
 >
 > I did not try toLocaleFormat() before but here is what I got using your
 same technique:
 >
 > Ubuntu:
 > {{{Array [ "Thu 26 Mar 2015 03:43:35 PM EDT", "3/26/2015, 3:43:35 PM"
 ]}}}
 > OSX:
 > {{{Array [ "Thu Mar 26 15:38:55 2015", "3/26/2015, 3:38:55 PM" ]}}}
 > Windows 7:
 > {{{Array [ "Thursday, March 26, 2015 3:45:01 PM", "3/26/2015, 3:45:01
 PM" ]}}}
 >
 > So it seems that toLocaleFormat() is a problem in any case.

 Yes, it looks like my Ubuntu VM may be using en_GB for some reason. I'm
 updating the ticket description to mention `new Date().toLocaleFormat()`.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15473#comment:6>
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