@deftypefun {size_t} {gnutls_mac_get_key_size} (gnutls_mac_algorithm_t @var{algorithm})
@var{algorithm}: is an encryption algorithm

Returns the size of the MAC key used in TLS. 

@strong{Returns:} length (in bytes) of the given MAC key size, or 0 if the
given MAC algorithm is invalid.
@end deftypefun