salix/db/routines/vn/procedures/cryptOff.sql

55 lines
1.6 KiB
SQL

DELIMITER $$
CREATE OR REPLACE DEFINER=`vn`@`localhost` PROCEDURE `vn`.`cryptOff`(vText VARCHAR(255), vKey VARCHAR(255), OUT vResult VARCHAR(255))
BEGIN
DECLARE vUncryptedText VARCHAR(255) DEFAULT '';
DECLARE vKeyLength INT;
DECLARE vKeyPosition INT DEFAULT 1;
DECLARE vKeyChar VARCHAR(1);
DECLARE vTextLength INT;
DECLARE vTextPosition INT DEFAULT 1;
DECLARE vTextChar VARCHAR(1);
DECLARE vUncryptedChar VARCHAR(1);
DECLARE vUncryptedCharPosition INT;
DECLARE vChain VARCHAR(255) DEFAULT '#$.-_0123456789abcdefghijklmnopqrstuvwxyz';
DECLARE vChainTextPosition INT;
DECLARE vChainKeyPosition INT;
DECLARE vChainLength INT;
SET vTextLength = LENGTH(vText);
SET vKeyLength = LENGTH(vKey);
SET vChainLength = LENGTH(vChain);
WHILE vTextPosition <= vTextLength DO
SET vTextChar = MID(vText,vTextPosition,1);
SET vKeyChar = MID(vKey,vKeyPosition,1);
SET vChainTextPosition = LOCATE(vTextChar, vChain);
SET vChainKeyPosition = LOCATE(vKeyChar, vChain);
SET vUncryptedCharPosition = vChainTextPosition - vChainKeyPosition;
IF vUncryptedCharPosition < 1 THEN
SET vUncryptedCharPosition = vUncryptedCharPosition + vChainLength;
END IF;
SET vUncryptedChar = MID(vChain, vUncryptedCharPosition,1);
SET vUncryptedText = CONCAT(vUncryptedText, vUncryptedChar);
SET vKeyPosition = IF(vKeyPosition = vKeyLength, 1,vKeyPosition + 1);
SET vTextPosition = vTextPosition + 1;
END WHILE;
SET vResult = vUncryptedText;
END$$
DELIMITER ;