anchor.diff:        expanded_key_material_length = expanded_key_material(Cipher),
         key_material_length = key_material(Cipher),
         iv_size = iv_size(Cipher),
  -      mac_algorithm = hash_algorithm(Hash),
  +      mac_algorithm = mac_algorithm(Hash),
         prf_algorithm = prf_algorithm(PrfHashAlg, Version),
         hash_size = hash_size(Hash)}.
   
  
positive.code: 
  hash_size(null) ->
      0;
  hash_size(md5) ->
      16;
  hash_size(sha) ->
  
negative.code: prf_algorithm(Algo, _) ->
      hash_algorithm(Algo).
  
  mac_algorithm(aead) ->
      aead;
  mac_algorithm(Algo) ->
      hash_algorithm(Algo).
  
  hash_algorithm(null)   -> ?NULL;
  hash_algorithm(md5)    -> ?MD5;
  hash_algorithm(sha)   -> ?SHA; %% Only sha always refers to "SHA-1"
  