Check all signatures regardless of the version.
The update_engine daemon had a fixed version number for the public key
used to verify both the metadata and whole payload signatures. The
public key itself is installed by the signer, implying that the source
code and the signer need to be in sync if we ever need to roll the
payload key.
This situation becomes more of a problem if we don't control when the
version number included in the source code is updated in the built
image sent for payload generation and signing.
This patch makes update_engine ignore the version number associated
with a signature and instead tries to verify all the signatures
included in the payload against the public key found in the code. This
effectively deprecates the key version number. To be compatible with
old versions, the version number 1 is included in all signatures.
Bug: 23601118
Test: Added unittests.
Change-Id: I4f96cc207ad6b9c011def5ce586d0e0e85af28ab
7 files changed