anchor.diff:      Salt = MsgPrivParams,
       IV = list_to_binary([?i32(EngineBoots), ?i32(EngineTime) | Salt]),
       %% Whatabout errors here???  E.g. not a mulitple of 8!
  -    Data = binary_to_list(crypto:block_decrypt(?BLOCK_CIPHER_AES, 
  -					       AesKey, IV, EncData)),
  +    Data = binary_to_list(crypto:crypto_one_time(?BLOCK_CIPHER_AES, 
  +                                                 AesKey, IV, EncData, false)),
       Data2 = snmp_pdus:strip_encrypted_scoped_pdu_data(Data),
       {ok, Data2}.
   
  
positive.code:     Packet   = snmp_pdus:enc_message_only(Message2),
      %% 6.3.1.2-4 is done by the crypto function
      %% 6.3.1.4
      MAC = binary_to_list(crypto:hmac(md5, AuthKey, Packet, 12)),
      %% ?vtrace("md5_auth_out -> crypto (md5) encoded"
      %%  	    "~n   MAC: ~w", [MAC]),
      %% 6.3.1.5
  
negative.code:     IV = list_to_binary(snmp_misc:str_xor(PreIV, Salt)),
      TailLen = (8 - (length(Data) rem 8)) rem 8,
      Tail = mk_tail(TailLen),
      EncData = crypto:crypto_one_time(?BLOCK_CIPHER_DES, 
                                       DesKey, IV, [Data,Tail], true),
      {ok, binary_to_list(EncData), Salt}.
  
  des_decrypt(PrivKey, MsgPrivParams, EncData) 
  