def mac
import bend-collections@1.0.0.0/src/crypto/poly1305/poly1305.bend as Poly1305import Base
66# The 16-byte tag of msg under key = r || s. (The match on msg only keeps a
67# proof's goal small while msg is unknown; both arms are the same.)
68def mac(+key: List<&2, U32>, +msg: List<&2, U32>) -> List<&2, U32>:
69 match msg:
70 case Nil{}: tag(key, [])
71 case b <> rest: tag(key, b <> rest)