anchor.diff:  
   %% TLS 1.3 ---------------------------------------------------
   -spec derive_secret(Secret::binary(), Label::binary(),
  -                    Messages::binary(), Algo::ssl_cipher_format:hash()) -> Key::binary().
  +                    Messages::iodata(), Algo::ssl_cipher_format:hash()) -> Key::binary().
   derive_secret(Secret, Label, Messages, Algo) ->
       Hash = crypto:hash(mac_algo(Algo), Messages),
       hkdf_expand_label(Secret, Label,
  
positive.code:          default_signature_schemes/1, signature_schemes/2,
           groups/1, groups/2, group_to_enum/1, enum_to_group/1, default_groups/1]).
  
  -export([derive_secret/4, hkdf_expand_label/5, hkdf_extract/3, hkdf_expand/4]).
  
  -type named_curve() :: sect571r1 | sect571k1 | secp521r1 | brainpoolP512r1 |
                         sect409k1 | sect409r1 | brainpoolP384r1 | secp384r1 |
  
negative.code:     %% } HkdfLabel;
      Label1 = << <<"tls13 ">>/binary, Label0/binary>>,
      LLen = size(Label1),
      Label = <<?BYTE(LLen), Label1/binary>>,
      Content = <<Label/binary, Context/binary>>,
      Len = size(Content),
      HkdfLabel = <<?UINT16(Len), Content/binary>>,
  