[tbb-bugs] #18112 [Tor Browser]: TorButton logs + Tor logs = timezone leak

[Tor Bug Tracker & Wiki]

#18112: TorButton logs + Tor logs = timezone leak
---------------------------+-----------------------------------------------
     Reporter:             |      Owner:  tbb-team
  cypherpunks              |     Status:  new
         Type:  defect     |  Milestone:
     Priority:  Medium     |    Version:  Tor: 0.2.7.6
    Component:  Tor        |   Keywords:  tor tbb-torlauncher timezone-leak
  Browser                  |  Parent ID:
     Severity:  Normal     |    Sponsor:
Actual Points:             |
       Points:             |
---------------------------+-----------------------------------------------
 TorButton messages are timestamped with UTC time, Tor's with local time.
 In combination the logs leak the user's timezone, free of context.  (Tor
 alone might leak the timezone depending on context.)

 Sample (here the timezone would be GMT+5):

 {{{
 [01-18 01:14:04] Torbutton DBUG: Got timer update, but no cookie change.
 Jan 18 06:14:30.000 [notice] Tried for 120 seconds to get a connection to
 [scrubbed]:80. Giving up.
 }}}

 Also the formats don't match.  The first is preferred, the second further
 leaks the locale language.

 Preferably, Tor should use UTC timestamps (perhaps controlled with a torrc
 setting, see #15607) and numeric months.

 As a temporary workaround, perhaps TorLauncher should set TZ to :UTC
 (similar to TorButton, but see also #16622) before spawning Tor.

 Also, in relation to the discussion in #15607:  Logs are not API!  Let
 stupid programs break if necessary.

 Tor Browser: 5.0.7
 Tor: 0.2.7.6
 TorLauncher: 0.2.7.7
 TorButton: 1.9.3.7

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18112>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online