Directory integrity verification requires directory hash value
to be set to security.ima.
This patch provides directory hash calculation.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
For debugging purpose it is nice to have evm hmac calculation for
labeling filesystem using hmac.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>