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- -- base64.sql - MySQL base64 encoding/decoding functions
- -- Copyright (C) 2006 Ian Gulliver
- --
- -- This program is free software; you can redistribute it and/or modify
- -- it under the terms of version 2 of the GNU General Public License as
- -- published by the Free Software Foundation.
- --
- -- This program is distributed in the hope that it will be useful,
- -- but WITHOUT ANY WARRANTY; without even the implied warranty of
- -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- -- GNU General Public License for more details.
- --
- -- You should have received a copy of the GNU General Public License
- -- along with this program; if not, write to the Free Software
- -- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- delimiter |
- DROP TABLE IF EXISTS base64_data |
- CREATE TABLE base64_data (c CHAR(1) BINARY, val TINYINT) |
- INSERT INTO base64_data VALUES
- ('A',0), ('B',1), ('C',2), ('D',3), ('E',4), ('F',5), ('G',6), ('H',7), ('I',8), ('J',9),
- ('K',10), ('L',11), ('M',12), ('N',13), ('O',14), ('P',15), ('Q',16), ('R',17), ('S',18), ('T',19),
- ('U',20), ('V',21), ('W',22), ('X',23), ('Y',24), ('Z',25), ('a',26), ('b',27), ('c',28), ('d',29),
- ('e',30), ('f',31), ('g',32), ('h',33), ('i',34), ('j',35), ('k',36), ('l',37), ('m',38), ('n',39),
- ('o',40), ('p',41), ('q',42), ('r',43), ('s',44), ('t',45), ('u',46), ('v',47), ('w',48), ('x',49),
- ('y',50), ('z',51), ('0',52), ('1',53), ('2',54), ('3',55), ('4',56), ('5',57), ('6',58), ('7',59),
- ('8',60), ('9',61), ('+',62), ('/',63), ('=',0) |
- DROP FUNCTION IF EXISTS BASE64_DECODE |
- CREATE FUNCTION BASE64_DECODE (input BLOB)
- RETURNS BLOB
- CONTAINS SQL
- 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 |
- DROP FUNCTION IF EXISTS BASE64_ENCODE |
- CREATE FUNCTION BASE64_ENCODE (input BLOB)
- RETURNS BLOB
- CONTAINS SQL
- 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 CHAR(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 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 |
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