Message authentication codes

The MAC algorithms, HMAC and AES-CBC-MAC, are listed in Algorithms, with the conditions AES-CBC-MAC comes with; the key they take, and what is checked about it, in Validating symmetric keys.

• COSE_Mac0 — a MAC without recipients
• COSE_Mac — a MAC whose recipients carry the authentication key
• The tag covers the MAC_structure — why a tag over the bare payload is bound to nothing