Legacy MySQL (v 5.1) BASE64 functions

base64.sql

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for base64_data
-- ----------------------------
DROP TABLE IF EXISTS `base64_data`;
CREATE TABLE `base64_data` (
  `c` char(1) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL,
  `val` tinyint(4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of base64_data
-- ----------------------------
INSERT INTO `base64_data` VALUES ('A', '0');
INSERT INTO `base64_data` VALUES ('B', '1');
INSERT INTO `base64_data` VALUES ('C', '2');
INSERT INTO `base64_data` VALUES ('D', '3');
INSERT INTO `base64_data` VALUES ('E', '4');
INSERT INTO `base64_data` VALUES ('F', '5');
INSERT INTO `base64_data` VALUES ('G', '6');
INSERT INTO `base64_data` VALUES ('H', '7');
INSERT INTO `base64_data` VALUES ('I', '8');
INSERT INTO `base64_data` VALUES ('J', '9');
INSERT INTO `base64_data` VALUES ('K', '10');
INSERT INTO `base64_data` VALUES ('L', '11');
INSERT INTO `base64_data` VALUES ('M', '12');
INSERT INTO `base64_data` VALUES ('N', '13');
INSERT INTO `base64_data` VALUES ('O', '14');
INSERT INTO `base64_data` VALUES ('P', '15');
INSERT INTO `base64_data` VALUES ('Q', '16');
INSERT INTO `base64_data` VALUES ('R', '17');
INSERT INTO `base64_data` VALUES ('S', '18');
INSERT INTO `base64_data` VALUES ('T', '19');
INSERT INTO `base64_data` VALUES ('U', '20');
INSERT INTO `base64_data` VALUES ('V', '21');
INSERT INTO `base64_data` VALUES ('W', '22');
INSERT INTO `base64_data` VALUES ('X', '23');
INSERT INTO `base64_data` VALUES ('Y', '24');
INSERT INTO `base64_data` VALUES ('Z', '25');
INSERT INTO `base64_data` VALUES ('a', '26');
INSERT INTO `base64_data` VALUES ('b', '27');
INSERT INTO `base64_data` VALUES ('c', '28');
INSERT INTO `base64_data` VALUES ('d', '29');
INSERT INTO `base64_data` VALUES ('e', '30');
INSERT INTO `base64_data` VALUES ('f', '31');
INSERT INTO `base64_data` VALUES ('g', '32');
INSERT INTO `base64_data` VALUES ('h', '33');
INSERT INTO `base64_data` VALUES ('i', '34');
INSERT INTO `base64_data` VALUES ('j', '35');
INSERT INTO `base64_data` VALUES ('k', '36');
INSERT INTO `base64_data` VALUES ('l', '37');
INSERT INTO `base64_data` VALUES ('m', '38');
INSERT INTO `base64_data` VALUES ('n', '39');
INSERT INTO `base64_data` VALUES ('o', '40');
INSERT INTO `base64_data` VALUES ('p', '41');
INSERT INTO `base64_data` VALUES ('q', '42');
INSERT INTO `base64_data` VALUES ('r', '43');
INSERT INTO `base64_data` VALUES ('s', '44');
INSERT INTO `base64_data` VALUES ('t', '45');
INSERT INTO `base64_data` VALUES ('u', '46');
INSERT INTO `base64_data` VALUES ('v', '47');
INSERT INTO `base64_data` VALUES ('w', '48');
INSERT INTO `base64_data` VALUES ('x', '49');
INSERT INTO `base64_data` VALUES ('y', '50');
INSERT INTO `base64_data` VALUES ('z', '51');
INSERT INTO `base64_data` VALUES ('0', '52');
INSERT INTO `base64_data` VALUES ('1', '53');
INSERT INTO `base64_data` VALUES ('2', '54');
INSERT INTO `base64_data` VALUES ('3', '55');
INSERT INTO `base64_data` VALUES ('4', '56');
INSERT INTO `base64_data` VALUES ('5', '57');
INSERT INTO `base64_data` VALUES ('6', '58');
INSERT INTO `base64_data` VALUES ('7', '59');
INSERT INTO `base64_data` VALUES ('8', '60');
INSERT INTO `base64_data` VALUES ('9', '61');
INSERT INTO `base64_data` VALUES ('+', '62');
INSERT INTO `base64_data` VALUES ('/', '63');
INSERT INTO `base64_data` VALUES ('=', '0');

-- ----------------------------
-- Function structure for BASE64_DECODE
-- ----------------------------
DROP FUNCTION IF EXISTS `BASE64_DECODE`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` FUNCTION `BASE64_DECODE`(input BLOB) RETURNS blob
    DETERMINISTIC
    SQL SECURITY INVOKER
BEGIN
	DECLARE ret BLOB DEFAULT '';
	DECLARE done TINYINT DEFAULT 0;

	IF input IS NULL THEN
		RETURN NULL;
	END IF;

each_block:
	WHILE NOT done DO BEGIN
		DECLARE accum_value BIGINT UNSIGNED DEFAULT 0;
		DECLARE in_count TINYINT DEFAULT 0;
		DECLARE out_count TINYINT DEFAULT 3;

each_input_char:
		WHILE in_count < 4 DO BEGIN
			DECLARE first_char CHAR(1);
	
			IF LENGTH(input) = 0 THEN
				RETURN ret;
			END IF;
	
			SET first_char = SUBSTRING(input,1,1);
			SET input = SUBSTRING(input,2);
	
			BEGIN
				DECLARE tempval TINYINT UNSIGNED;
				DECLARE error TINYINT DEFAULT 0;
				DECLARE base64_getval CURSOR FOR SELECT val FROM base64_data WHERE c = first_char;
				DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET error = 1;
	
				OPEN base64_getval;
				FETCH base64_getval INTO tempval;
				CLOSE base64_getval;

				IF error THEN
					ITERATE each_input_char;
				END IF;

				SET accum_value = (accum_value << 6) + tempval;
			END;

			SET in_count = in_count + 1;

			IF first_char = '=' THEN
				SET done = 1;
				SET out_count = out_count - 1;
			END IF;
		END; END WHILE;

		-- We've now accumulated 24 bits; deaccumulate into bytes

		-- We have to work from the left, so use the third byte position and shift left
		WHILE out_count > 0 DO BEGIN
			SET ret = CONCAT(ret,CHAR((accum_value & 0xff0000) >> 16));
			SET out_count = out_count - 1;
			SET accum_value = (accum_value << 8) & 0xffffff;
		END; END WHILE;
	
	END; END WHILE;

	RETURN ret;
END
;;
DELIMITER ;

-- ----------------------------
-- Function structure for BASE64_ENCODE
-- ----------------------------
DROP FUNCTION IF EXISTS `BASE64_ENCODE`;
DELIMITER ;;
CREATE DEFINER=`YOUR DATABASE`@`%` FUNCTION `BASE64_ENCODE`(input BLOB) RETURNS blob
    DETERMINISTIC
    SQL SECURITY INVOKER
BEGIN
    DECLARE ret BLOB DEFAULT '';
    DECLARE done TINYINT DEFAULT 0;
    IF input IS NULL THEN
        RETURN NULL;
    END IF;
each_block:
    WHILE NOT done DO BEGIN
        DECLARE accum_value BIGINT UNSIGNED DEFAULT 0;
        DECLARE in_count TINYINT DEFAULT 0;
        DECLARE out_count TINYINT;
each_input_char:
        WHILE in_count < 3 DO BEGIN
            DECLARE first_char BLOB(1);

            IF LENGTH(input) = 0 THEN
                SET done = 1;
                SET accum_value = accum_value << (8 * (3 - in_count));
                LEAVE each_input_char;
            END IF;

            SET first_char = SUBSTRING(input,1,1);
            SET input = SUBSTRING(input,2);

            SET accum_value = (accum_value << 8) + ASCII(first_char);
            SET in_count = in_count + 1;
        END; END WHILE;

        -- We've now accumulated 24 bits; deaccumulate into base64 characters
        -- We have to work from the left, so use the third byte position and shift left
        CASE
            WHEN in_count = 3 THEN SET out_count = 4;
            WHEN in_count = 2 THEN SET out_count = 3;
            WHEN in_count = 1 THEN SET out_count = 2;
            ELSE RETURN ret;
        END CASE;

        WHILE out_count > 0 DO BEGIN
            BEGIN
                DECLARE out_char CHAR(1);
                DECLARE base64_getval CURSOR FOR SELECT c FROM core_base64_data WHERE val = (accum_value >> 18);
                OPEN base64_getval;
                FETCH base64_getval INTO out_char;
                CLOSE base64_getval;
                SET ret = CONCAT(ret,out_char);
                SET out_count = out_count - 1;
                SET accum_value = accum_value << 6 & 0xffffff;
            END;
        END; END WHILE;
        CASE
            WHEN in_count = 2 THEN SET ret = CONCAT(ret,'=');
            WHEN in_count = 1 THEN SET ret = CONCAT(ret,'==');
            ELSE BEGIN END;
        END CASE;

    END; END WHILE;
    RETURN ret;
END
;;
DELIMITER ;

Nice one, works like charm, but having issues while decoding special characters like ö, ørn Eidsvåg. Any idea on how to resolve this and update the decode function to support the same.
Any help or assistance would be appreciated.