According to the RFC 4096 (section 3.3.1) the DATA chunk needs to be
padded to a boundary of 4 bytes with zeros. This patch addresses that
requirement.
At the same time, this patch takes care of adding some hardening for
corner-cases where the transmitted tag could be wrong.
Change-Id: I3b653926e9933d0d3d46bc5f37eaceefd932e874
Signed-off-by: Marco Varlese <marco.varlese@suse.com>