Retrieving the mac is necessary during the handling of the SMC, since the context is generated from the specified keys therein. Therefore, it is necessary to check the MAC right after generation and ensure the authenticity of the message. If it is not given, the message must be rejected. Signed-off-by: Eduard Vlad <eduard.vlad@rwth-aachen.de> Co-authored-by: Guido Casati <hello@guidocasati.com>