anchor.diff:      list_to_binary(Ds);
   int_to_bin_neg(X,Ds) ->
       int_to_bin_neg(X bsr 8, [(X band 255)|Ds]).
  +
  +rfc_1321_msgs() ->
  +    [<<"">>, 
  +     <<"a">>,
  +     <<"abc">>, 
  +     <<"message digest">>,
  +     <<"abcdefghijklmnopqrstuvwxyz">>,
  +     <<"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789">>,
  +     <<"12345678901234567890123456789012345678901234567890123456789012345678901234567890">>
  +    ].
  +
  +rfc_1321_md5_digests() ->
  +    [hexstr2bin("d41d8cd98f00b204e9800998ecf8427e"),
  +     hexstr2bin("0cc175b9c0f1b6a831c399e269772661"),
  +     hexstr2bin("900150983cd24fb0d6963f7d28e17f72"),
  +     hexstr2bin("f96b697d7cb7938d525a2f31aaf161d0"),
  +     hexstr2bin("c3fcd3d76192e4007dfb496cca67e13b"),
  +     hexstr2bin("d174ab98d277d9f5a5611c2c9f419d9f"),
  +     hexstr2bin("57edf4a22be3c955ac49da2e2107b67a")].
  
positive.code: end_per_testcase(_Name,Config) ->
      Config.
  
  group_config(sha = Type, Config) ->
      Msgs = [rfc_4634_test1(), rfc_4634_test2_1(),long_msg()],
      Digests = rfc_4634_sha_digests() ++ [long_sha_digest()],
  
negative.code: -include_lib("common_test/include/ct.hrl").
  -compile(export_all).
  
  all() -> [{group, md5},
            {group, sha},
            {group, sha256},
            {group, sha512},
            {group, rsa},
            rand_bytes
           ].
  
  groups() -> [{md5, [], [hash]},
               {sha, [], [hash]},
               {sha256, [], [hash]},
               {sha512, [], [hash]},
               {rsa, [], [sign_verify, public_encrypt]}
  