This module implements the HMAC algorithm as described by RFC 2104.
The module is based on the C library cifra.
Return a new hmac object. key is a bytes or bytearray or string object giving the secret key. hashfn is an instance of a hash function to use in hmac generation. It supports any class in the
Update the hmac object with the string data. Repeated calls are equivalent to a single call with the concatenation of all the arguments: m.update(a); m.update(b) is equivalent to m.update(a+b).
Return the digest of the strings passed to the update method so far. The size depends on hashfn.
Like digest except the digest is returned as a string containing only hexadecimal digits.