The implementation does not support [COSE_Mac0 signatures](https://www.ietf.org/archive/id/draft-tschofenig-rats-psa-token-09.html#section-5), which [TF-M profile small](https://tf-m-user-guide.trustedfirmware.org/technical_references/design_docs/profiles/tfm_profile_small.html?highlight=mac0) can produce.