anchor.diff:  group_config(chacha20_poly1305, Config) ->
       AEAD = chacha20_poly1305(),
       [{aead, AEAD} | Config];
  +group_config(chacha20, Config) ->
  +    Stream = chacha20(),
  +    [{stream, Stream} | Config];
   group_config(poly1305, Config) ->
       V = [%% {Key, Txt, Expect}
            {%% RFC7539 2.5.2
  
positive.code:              "gcmEncryptExtIV192.rsp",
               "gcmEncryptExtIV256.rsp"]).
  
  %% https://tools.ietf.org/html/rfc7539#appendix-A.5
  chacha20_poly1305() ->
      [
  
negative.code:      {no_blowfish_ofb64, [], [no_support, no_block]},
       {no_aes_ige256, [], [no_support, no_block]},
       {no_chacha20_poly1305, [], [no_support, no_aead]},
       {no_chacha20, [], [no_support, no_stream_ivec]},
       {no_rc2_cbc, [], [no_support, no_block]},
       {no_rc4, [], [no_support, no_stream]},
       {api_errors, [], [api_errors_ecdh]}
  