get_dec_val_1.sql

Oracle PLSQL for DBAs 源代码

CREATE OR REPLACE FUNCTION get_dec_val (
   p_in_val   VARCHAR2,
   p_key      VARCHAR2,
   p_iv       VARCHAR2 := NULL,
   p_which    NUMBER := 0
)
   RETURN VARCHAR2
IS
   l_dec_val   VARCHAR2 (2000);
   l_iv        VARCHAR2 (2000);
BEGIN
   IF p_which = 0
   THEN
      IF LENGTH (p_key) < 16
      THEN
         raise_application_error
                               (-20001,
                                'Key length less than 16 for two-pass scheme'
                               );
      END IF;
   ELSIF p_which = 1
   THEN
      IF LENGTH (p_key) < 24
      THEN
         raise_application_error
                             (-20002,
                              'Key length less than 24 for three-pass scheme'
                             );
      END IF;
   ELSE
      raise_application_error (-20003,
                                  'Incorrect value of which '
                               || p_which
                               || '; must be 0 or 1'
                              );
   END IF;

   l_iv := RPAD (p_iv, (8 * ROUND (LENGTH (p_iv) / 8, 0) + 8));
   l_dec_val :=
      DBMS_OBFUSCATION_TOOLKIT.des3decrypt
                (input_string      => UTL_RAW.cast_to_varchar2
                                                           (HEXTORAW (p_in_val)
                                                           ),
                 key_string        => p_key,
                 iv_string         => l_iv,
                 which             => p_which
                );
   RETURN RTRIM (l_dec_val);
END;
/