anchor.diff:  check_hash(_, _) ->
       ok. %% TODO check this 
   
  -mac_hash(?NULL, {_,_}, _MacSecret, _SeqNo, _Type,
  +mac_hash({_,_}, ?NULL, _MacSecret, _SeqNo, _Type,
   	 _Length, _Fragment) ->
       <<>>;
   mac_hash({3, 0}, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) ->
  
positive.code: 	{ok, []} ->
  	    lists:map(Fun, ?DEFAULT_SUPPORTED_VERSIONS);
  	{ok, Vsns} when is_list(Vsns) ->
  	    lists:map(Fun, Vsns);
  	{ok, Vsn} ->
  	    [Fun(Vsn)]
      end.
  
  %%--------------------------------------------------------------------
  %% Function: is_acceptable_version(Version) -> true | false
  
negative.code:     {3, 1};
  protocol_version(sslv3) ->
      {3, 0};
  protocol_version(sslv2) -> %% Backwards compatibility
      {2, 0};
  protocol_version({3, 2}) ->
      'tlsv1.1';
  protocol_version({3, 1}) ->
      tlsv1;
  protocol_version({3, 0}) ->
      sslv3.
  %%--------------------------------------------------------------------
  %% Function: protocol_version(Version1, Version2) -> #protocol_version{}
  %%     Version1 = Version2 = #protocol_version{}
  