[tor-bugs] #27268 [Applications/Tor Browser]: preferences cleanup

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#27268: preferences cleanup
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 Reporter:  rzb                             |          Owner:  tbb-team
     Type:  defect                          |         Status:  new
 Priority:  Medium                          |      Milestone:
Component:  Applications/Tor Browser        |        Version:
 Severity:  Normal                          |     Resolution:
 Keywords:  ff60-esr, TorBrowserTeam201809  |  Actual Points:
Parent ID:                                  |         Points:
 Reviewer:                                  |        Sponsor:
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Comment (by tom):

 Replying to [comment:17 Thorin]:
 > **RFP Redundant**
 > - `dom.enable_resource_timing` & `dom.enable_performance`
 >    * check with tom, 100% sure this is covered by tom's RFP
 reduceTimerPrecision prefs
 >    * not sure if RFP ''overrides'' these: i.e disabling the API vs
 rounding it: for all I know you might be causing perf issues: ask tom :)

 With RFP set, all of these timestamps will be clamped/jittered.
 Additionally, RFP has the behavior of setting dom.enable_performance to
 false (so you don't need to set that pref.)

 However RFP does not have the same behavior for dom.enable_resource_timing
 - so you may want to disable that explicitly.

 > **RFP Redundant Part 2**
 > - **NOTE**: RFP overrides these, some are deprecated AFAICT (e.g
 vendor), current values are out of sync with ESR68, and maintaining it is
 extra work
 >  - `general.appname.override`
 >  - `general.appversion.override`
 >  - `general.oscpu.override`
 >  - `general.platform.override`
 >  - `general.productSub.override`
 >  - `general.buildID.override`
 >  - `general.useragent.vendor`
 >  - `general.useragent.vendorSub`

 Yeah all of these should be deleted from tor's js file. With RFP enabled
 they do nothing.

 > **RFP Redundant Part 3**: probably changes fingerprint, maybe entropy
 > - `dom.netinfo.enabled` - https://bugzilla.mozilla.org/1372072
 >    * this pref disables the API: you get an error or "undefined"
 >    * the pref is only default true on mobile: RFP returns "unknown"
 >    * so removing the pref would create two buckets: mobile vs desktop

 RFP ought to return one value for all situations, right? (I have no
 verified.)

 > - `media.webspeech.synth.enabled` - https://bugzilla.mozilla.org/1333641
 >    * same thing: disabling vs spoofing
 >    * needs double checking: but the new FP is universal AFAIK

 I don't remember what RFP does to this one.

 > - `media.video_stats.enabled` - https://bugzilla.mozilla.org/1369309
 >    * same thing: disabling vs spoof
 >    * needs double checking: some RFP values are the same, some are
 bucketized so **may** create more entropy: check with tom

 RFP should give the same results for all users. The value is dependent on
 the playback time of the video however. (e.g. you'll get a different
 answer for 1 second vs 10 seconds into the video.)

 > - `dom.gamepad.enabled` - https://bugzilla.mozilla.org/1337161
 >    * RFP hides gamepad from content
 >    * not sure if the FP changes and is universal

 Setting this pref to false removes the objects from the DOM; setting RFP
 just always reports "No gamepads."



 Great list.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27268#comment:18>
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