Oracle中加密包的使用

create or replace function DesEncode(string_in in varchar2) return raw is  string_in_raw RAW(128) := UTL_RAW.CAST_TO_RAW(string_in);  key_string    varchar2(32) := 'ipbExpert';  key_raw       RAW(128) := UTL_RAW.CAST_TO_RAW(key_string);  encrypted_raw RAW(128);begin  encrypted_raw := dbms_crypto.Encrypt(src => string_in_raw,                                       typ => DBMS_CRYPTO.encrypt_rc4,                                       key => key_raw);  return encrypted_raw;end;/create or replace function DesDecode(raw_in in raw) return varchar2 is  string_out    varchar2(50);  key_string    varchar2(32) := 'ipbExpert';  key_raw       RAW(128) := UTL_RAW.CAST_TO_RAW(key_string);  decrypted_raw RAW(128);begin  decrypted_raw := dbms_crypto.Decrypt(src => raw_in,                                       typ => DBMS_CRYPTO.encrypt_rc4,                                       key => key_raw);  string_out    := UTL_RAW.cast_to_varchar2(decrypted_raw);  return string_out;end;/