带有salt的MySQL encrypt()在密码后接受随机字符

Question

我有一个包含用户名和加密密码的表。

密码是通过 MySQL encrypt() 和盐(密码的前两个字符)一起加密的。

最近我注意到 MySQL 接受密码，即使密码末尾包含随机字符也是如此。

假设我们有这样一张表:

SET NAMES utf8;
SET foreign_key_checks = 0;
SET time_zone = 'SYSTEM';
SET sql_mode = 'NO_AUTO_VALUE_ON_ZERO';

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) DEFAULT NULL,
  `password` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO `user` (`id`, `username`, `password`) VALUES
(11,    'ricardomontalban', ENCRYPT(11111111,11));

现在我查询我的用户:

-- The following shows the appropriate response --
SELECT * FROM user WHERE username = "ricardomontalban" AND password = ENCRYPT(11111111,11);

-- HOWEVER, the following query also shows a result, even with random characters appended!!! --
SELECT * FROM user WHERE username = "ricardomontalban" AND password = ENCRYPT("11111111-55669964s5465sqsfqsdf",11);

-- No problem with prepended random characters though --
SELECT * FROM user WHERE username = "ricardomontalban" AND password = ENCRYPT("smlkfjmlsdkfjslqf-11111111",11);

我创建了一个 SQL Fiddle 来实时显示这个例子: http://sqlfiddle.com/#!2/898d5/9

我做错了什么？我什至应该使用这种加密方法吗？ 非常感谢任何建议。

Answer 1

根据 documentation :

ENCRYPT() ignores all but the first eight characters of str, at least on some systems. This behavior is determined by the implementation of the underlying crypt() system call.