anchor.diff:  validate_option(certfile, Value) when is_binary(Value) ->
       Value;
   validate_option(certfile, Value) when is_list(Value) ->
  -    list_to_binary(Value);
  +    binary_filename(Value);
   
   validate_option(key, undefined) ->
       undefined;
  
positive.code:     undefined;
  validate_option(srp_identity, {Username, Password})
    when is_list(Username), is_list(Password), Username =/= "", length(Username) =< 255 ->
      {list_to_binary(Username), list_to_binary(Password)};
  
  validate_option(ciphers, Value)  when is_list(Value) ->
      Version = tls_record:highest_protocol_version([]),
  
negative.code: validate_option(dhfile, Value) when is_binary(Value) ->
      Value;
  validate_option(dhfile, Value) when is_list(Value), Value =/= "" ->
      binary_filename(Value);
  validate_option(psk_identity, undefined) ->
      undefined;
  validate_option(psk_identity, Identity)
    when is_list(Identity), Identity =/= "", length(Identity) =< 65535 ->
      binary_filename(Identity);
  validate_option(user_lookup_fun, undefined) ->
      undefined;
  validate_option(user_lookup_fun, {Fun, _} = Value) when is_function(Fun, 3) ->
  