[tor-bugs] #28685 [Applications/rbm]: Tor Browser for Android needs a more dynamic Build ID

[Tor Bug Tracker & Wiki]

#28685: Tor Browser for Android needs a more dynamic Build ID
----------------------------------+------------------------
     Reporter:  sysrqb            |      Owner:  boklm
         Type:  defect            |     Status:  new
     Priority:  Medium            |  Milestone:
    Component:  Applications/rbm  |    Version:
     Severity:  Normal            |   Keywords:  tbb-mobile
Actual Points:                    |  Parent ID:
       Points:                    |   Reviewer:
      Sponsor:                    |
----------------------------------+------------------------
 Currently, the build id only changes when the Firefox version changes and
 when the copyright year changes. Unfortunately, when building the APK,
 Mozilla expect the build id changes between every build. They use the
 build id and derive the Android version code (version number) from this.
 Unfortunately, they only use part of the buildid and they discard lower
 bits. This doesn't fit well with the current `get-moz-build-date` script
 because:
   1) if the firefox build date and copyright year remain the same, then
 the build id remains the same
   2) if the patch version increases (such as 60.3.0 to 60.3.1), then the
 Android version code doesn't change (due to discarded lower bits)

 I think we can solve 1. by incorporating the tor browser version number
 into the calculation. Solving 2. may require multiplying by at least 3600
 (therefore offsets the division by 60*60), i think.
 https://gitweb.torproject.org/tor-
 browser.git/tree/python/mozbuild/mozbuild/android_version_code.py?h=tor-
 browser-60.3.0esr-8.5-1#n33

 {{{
 $ perl get-moz-build-date 2018 60.3.0
 export MOZ_BUILD_DATE=20180204040101

 $ python python/mozbuild/mozbuild/android_version_code.py --verbose
 --with-android-cpu-arch armeabi-v7a --with-android-min-sdk-version 16
 --with-android-max-sdk-version 26 20180204040101
 2015539361


 $ perl get-moz-build-date 2018 60.3.1
 export MOZ_BUILD_DATE=20180204040201

 $ python python/mozbuild/mozbuild/android_version_code.py --verbose
 --with-android-cpu-arch armeabi-v7a --with-android-min-sdk-version 16
 --with-android-max-sdk-version 26 20180204040201
 2015539361


 $ perl get-moz-build-date 2018 60.4.0
 export MOZ_BUILD_DATE=20180204050101

 $ python python/mozbuild/mozbuild/android_version_code.py --verbose
 --with-android-cpu-arch armeabi-v7a --with-android-min-sdk-version 16
 --with-android-max-sdk-version 26 20180204050101
 2015539369
 }}}

 Notice the android version code is the same for `60.3.0` and `60.3.1`.

 Currently, the script with the current Tor Browser Build ID is:
 {{{
 import math
 import time

 fmt = '%Y%m%d%H%M%S'
 buildid = "20180204040101"
 V1_CUTOFF = 20150801000000

 build = time.strptime(str(buildid), fmt)
 cutoff = time.strptime(str(V1_CUTOFF), fmt)

 base = int(math.floor((time.mktime(build) - time.mktime(cutoff)) / (60.0 *
 60.0)))
 version = 0b1111000001000000000000000000000
 version |= base << 3
 version |= 1 << 0
 print(version)
 }}}

 Something else I noticed is this current scheme only provides 8 android
 version codes between 60.3.0 (2015539361) and 60.4.0 (2015539369). We
 probably want more than that - but this may be accomplished when adjusting
 the other bits.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28685>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online