oracle my2_ep解密

SELECT CUSCODE,
       UTL_RAW.cast_to_nvarchar2(UTL_RAW.bit_xor(UTL_ENCODE.base64_decode(UTL_RAW.cast_to_raw(SUBSTR(CAST(客户密码 AS VARCHAR2(50)),6))),
                                                UTL_RAW.cast_to_raw('#&^*')))
  FROM TAB_CUSTOMER WHERE length(客户密码) > 1 AND ROWNUM < 20