tree 322a5968015ba9bb25726f2db1c743b83d26d54e
parent 5fdb80059e6cb1ffb3590ac3415c9072c1a8b17c
author Rubin Xu <rubinxu@google.com> 1509464432 +0000
committer android-build-team Robot <android-build-team-robot@google.com> 1513298819 +0000

Swap the order of synthetic password wrapping

Synthetic password is double encrypted by both a random auth-bound keymaster
key and a secret derived from user password. In order to avoid a password
verification oracle without rate limiting, synthetic password needs to be
encrypted by the derived secret first, and then the auth-bound key. This
change corrects the order of encryptions, as well as adds an upgrade path to
refresh existing credentials.

Test: Running an old build with existing password, flash to new build,
      verify the device unlocks successfully.
Bug: 68694819

Change-Id: Ifdaa01f3f4ddd5bb3f3d808d38f440ced729034f
Merged-In: Ifdaa01f3f4ddd5bb3f3d808d38f440ced729034f
(cherry picked from commit 78acfe71d5d527ec727ffa3ad33f0de6255d60d7)