tree 1173db93bffda2cf3bdbdeedc759548c003d1163
parent 8e2dce0ccc2699a0df9d8473fa586811f4b1b69c
author Tianjie <xunchang@google.com> 1610690713 -0800
committer Tianjie Xu <xunchang@google.com> 1611858419 +0000

Calculate vbmetadigest of inactive slot

We want to improve the security of the keystore encryption key for resume
on reboot. One AI is to create the key with the vbmeta digest of the
next slot to boot into. After reboot, the decryption will fail if
ro.boot.vbmeta.digest of the new slot doesn't match the calculated value
before reboot.

Since update_engine manages the slot switch, let it calculate the digest
as well.

Bug: 177625570
Test: do a update, check that the sysprop is set.

Change-Id: I74b20fca72f6946d980b93d76990f1c8b8f246a9