oracle 9i 使用dbms_obfuscation_toolkit加密解密



加密(encrypt)解密(decrypt)采用
Oracle DBMS_OBFUSCATION_TOOLKIT package.
利用这个包,我们可以对数据进行DES,Triple
DES或者MD5加密.
DESGETKEY   --产生密钥,用于DES算法

   DES3GETKEY  -- 产生密钥,用于Triple
DES算法

   DESENCRYPT  -- 用DES算法加密数据
   DESDECRYPT  --
用DES算法解密数据
   DES3ENCRYPT --
用Triple DES算法加密数据
   DES3DECRYPT --
用DES算法解密数据
   MD5         --
用MD5算法加密数据

使用DES算法和Triple
DES算法的特征之一. 是输入长度必须是8的倍数,而输出也是8的倍数,所以我们的字段长度也是8的倍数.如果输入不是8的倍数,会报错.
The key specified is too short for
the algorithm. DES requires a key of at least 8 bytes. Triple DES requires a key of least 16 bytes in two-key mode and 24 bytes in three-key mode.

也可以使用DESGETKEY获取Key

PROCEDURE DESGETKEY

参数名称                       类型                    输入/输出默认值?

------------------------------ ----------------------- ------ --------

 SEED                           RAW                     IN

 KEY                            RAW                     OUT

create or replace package PG_ENCRYPT_DECRYPT
is

  function getkey return varchar2;

  function encrypt(p_in varchar2) return varchar2;

  function decrypt(p_in varchar2) return varchar2;

end;

create or replace package body PG_ENCRYPT_DECRYPT is

  function getkey return varchar2 is

    v_type varchar2(1) := '';

    v_rtn  varchar2(40);

    v_key  varchar2(20) := 'AAAA1234';

  begin

    if (v_type = '1') then

      select to_char(sysdate, 'yyyy') into v_key from dual;

    elsif (v_type = '2') then

      select to_char(sysdate, 'yyyyQ') into v_key from dual;

    elsif (v_type = '3') then

      select to_char(sysdate, 'yyyymm') into v_key from dual;

    elsif (v_type = '4') then

      select to_char(sysdate, 'yyyyWW') into v_key from dual;

    elsif (v_type = '5') then

      select to_char(sysdate, 'yyyymmdd') into v_key from dual;

    end if;

    for i in 1 .. length(v_key) loop

      v_rtn := v_rtn || to_char(ascii(substr(v_key, i, 1)));

    end loop;

    return v_rtn;

  end;

  /* Creating function DECRYPT*/

  function encrypt(p_in varchar2) return varchar2 is

    v_in  varchar2(320);

    v_out varchar2(1000);

  begin

    v_in  := rpad(p_in, (trunc(length(p_in) / 8) + 1) * 16, chr(0));

    v_out := UTL_RAW.CAST_TO_RAW(dbms_obfuscation_toolkit.desencrypt(input_string => v_in,

                                                                     key_string   => getkey()));

    return v_out;

  end;

  /*Creating function ENCRYPT*/

  function decrypt(p_in varchar2) return varchar2 is

    v_out varchar2(1000);

  begin

    dbms_obfuscation_toolkit.DESDECRYPT(input_string     => UTL_RAW.CAST_TO_varchar2(p_in),

                                        key_string       => getkey(),

                                        decrypted_string => v_out);

    v_out := rtrim(v_out, chr(0));

    return v_out;

  end;

end;

参考资料

http://blog.chinaunix.net/uid-90674-id-2436668.html

http://www.anbob.com/archives/1313.html

http://www.anbob.com/archives/1326.html

查看dbms_obfuscation_toolkit定义

oracle~>desc dbms_obfuscation_toolkit;