HMAC.Noalloc
Versions of these functions which write their output in a buffer passed in as an argument
val mac :
alg:SharedDefs.HashDefs.alg ->
key:bytes ->
msg:bytes ->
tag:bytes ->
unit
mac alg key msg tag
computes the HMAC of msg
based on hashing algorithm alg
using key key
and writes the result in tag
. The `tag` buffer needs to satisfy the size requirements for the output buffer.