in corner cases, encode_msg and decode_msg_frame fail Change-Id: I28b3ddcdce80c7c5b71afe19b11bb73cd761f595 Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/22211 Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de> Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de> Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>