用户可从哪台主机连接mysql数据库是由mysql.user表中的host值来确定的。
默认情况下host值都为localhost,如用户需要从任何主机都可连接mysql数据库,可将host值置为%,host值也可为固定IP地址,表示该用户只能从该IP地址所属主机登录连接mysql。 mysql> select user,host from mysql.user; +------------------+-----------+ | user | host | +------------------+-----------+ | mysql.infoschema | localhost | | mysql.session | localhost | | mysql.sys | localhost | | root | localhost | +------------------+-----------+
将user用户的host值设置为%
mysql> update mysql.user set host='%' where user='root'; Query OK, 1 row affected (0.01 sec) Rows matched: 1 Changed: 1 Warnings: 0
刷新权限
mysql> flush privileges; Query OK, 0 rows affected (0.01 sec)
MySQL 系统自带有 validate_password 插件,此插件可以验证密码强度,未达到规定强度的密码则不允许被设置。MySQL 5.7版本默认是不启用该插件的,8.0 版本默认情况下启用该插件。
mysql> show variables like'validate_password%'; Empty set (0.00 sec) --查询参数后发现参数不存在,我们需要安装一下validate_password 插件。
安装插件
mysql> INSTALL PLUGIN validate_password SONAME 'validate_password.so'; Query OK, 0 rows affected (0.05 sec) --插件安装完成后,即可看到相关参数。 mysql> show variables like'validate_password%'; +--------------------------------------+--------+ | Variable_name | Value | +--------------------------------------+--------+ | validate_password_check_user_name | OFF | | validate_password_dictionary_file | | | validate_password_length | 8 | | validate_password_mixed_case_count | 1 | | validate_password_number_count | 1 | | validate_password_policy | MEDIUM | | validate_password_special_char_count | 1 | +--------------------------------------+--------+ 7 rows in set (0.00 sec) --安装插件后密码强度默认值是MEDIUM,不影响我们现有弱密码用户登录数据库
mysql> show variables like'validate_password%'; +--------------------------------------+--------+ | Variable_name | Value | +--------------------------------------+--------+ | validate_password.check_user_name | ON | | validate_password.dictionary_file | | | validate_password.length | 8 | | validate_password.mixed_case_count | 1 | | validate_password.number_count | 1 | | validate_password.policy | MEDIUM | | validate_password.special_char_count | 1 | +--------------------------------------+--------+ 7 rows in set (0.00 sec)
validate_password 插件参数解释:
1、validate_password_policy 代表的密码策略,默认是MEDIUM 可配置的值有以下: 0 or LOW 仅需需符合密码长度(由参数validate_password_length指定) 1 or MEDIUM 满足LOW策略,同时还需满足至少有1个数字,小写字母,大写字母和特殊字符 2 or STRONG 满足MEDIUM策略,同时密码不能存在字典文件(dictionary file)中 2、validate_password_dictionary_file 用于配置密码的字典文件,当validate_password_policy设置为STRONG时可以配置密码字典文件,字典文件中存在的密码不得使用。 3、validate_password_length 用来设置密码的最小长度,默认值是8 4、validate_password_mixed_case_count 当validate_password_policy设置为MEDIUM或者STRONG时,密码中至少同时拥有的小写和大写字母的数量,默认是1最小是0;默认是至少拥有一个小写和一个大写字母。 5、validate_password_number_count 当validate_password_policy设置为MEDIUM或者STRONG时,密码中至少拥有的数字的个数,默认1最小是0 6、validate_password_special_char_count 当validate_password_policy设置为MEDIUM或者STRONG时,密码中至少拥有的特殊字符的个数,默认1最小是0
mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 4 rows in set (0.00 sec) --用户密码过期状态由password_expired控制,过期时间由password_lifetime控制。
使test用户密码立即过期
mysql> create user test identified by'Huawei12#$'; Query OK, 0 rows affected (0.05 sec) mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | test | % | N | NULL | 2022-05-16 22:52:51 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 5 rows in set (0.00 sec) mysql> alter user 'test'@'%' password expire; Query OK, 0 rows affected (0.01 sec) mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | test | % | Y | NULL | 2022-05-16 22:52:51 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 5 rows in set (0.00 sec --test用户的password_expired列值立即变为了Y,重新用test用户登录会提示你修改密码。
修改账号密码永不过期
mysql> alter user 'test'@'%' password expire never; Query OK, 0 rows affected (0.15 sec) mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | test | % | N | 0 | 2022-05-16 22:57:55 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 5 rows in set (0.01 sec) --test用户的password_lifetime列值立即变为了0。
设置账号密码90天过期
mysql> ALTER USER 'test'@'%' PASSWORD EXPIRE INTERVAL 90 DAY; Query OK, 0 rows affected (0.01 sec) mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | test | % | N | 90 | 2022-05-16 22:57:55 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 5 rows in set (0.00 sec)
将账号test使用默认的密码过期全局策略
mysql> ALTER USER 'test'@'%' PASSWORD EXPIRE DEFAULT; Query OK, 0 rows affected (0.06 sec) mysql> select user,host,password_expired,password_lifetime,password_last_changed,account_locked from mysql.user; +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | user | host | password_expired | password_lifetime | password_last_changed | account_locked | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ | root | % | N | NULL | 2021-12-30 11:28:07 | N | | test | % | N | NULL | 2022-05-16 22:57:55 | N | | mysql.infoschema | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.session | localhost | N | NULL | 2021-12-30 11:14:57 | Y | | mysql.sys | localhost | N | NULL | 2021-12-30 11:14:57 | Y | +------------------+-----------+------------------+-------------------+-----------------------+----------------+ 5 rows in set (0.00 sec)
设置密码全局过期策略
mysql> show variables like 'default_password_lifetime'; +---------------------------+-------+ | Variable_name | Value | +---------------------------+-------+ | default_password_lifetime | 0 | +---------------------------+-------+ 1 row in set (0.00 sec) --默认为0,表示密码不过期。 mysql> SET GLOBAL default_password_lifetime = 90; Query OK, 0 rows affected (0.00 sec) --设置密码90天过期 mysql> show variables like 'default_password_lifetime'; +---------------------------+-------+ | Variable_name | Value | +---------------------------+-------+ | default_password_lifetime | 90 | +---------------------------+-------+ 1 row in set (0.01 sec) # 写入配置文件使得重启生效 [mysqld] default_password_lifetime = 90
修改密码有很多种方法,这里记录最简单的一种。
--5.7和8.0均可用这种方式修改。 mysql> alter user root@'%' identified with mysql_native_password by'Huawei12#$';
这里要注意一个问题,我们这修改的是root@'%'这个用户的密码,也就是修改的root远程登录时候的密码,本底登录也就是root@'localhost’的密码并没有修改。
--用户表里面有root@'%'和root@'localhost',user表的user和host列是双主键。 mysql> select user,host from mysql.user; +---------------+-----------+ | user | host | +---------------+-----------+ | root | % | | mysql.session | localhost | | mysql.sys | localhost | | root | localhost | +---------------+-----------+ 4 rows in set (0.00 sec) --(root,%),表示可以远程登录,并且是除服务器外的其他任何终端,%表示任意IP都可登录。 --(root,localhost), 表示可以本地登录,即可以在服务器上登陆,localhost则只允许本地登录。 --(root,127.0.0.1 ),表示可以本机登陆,即可以在服务器上登陆
忘记root密码
--MySQL 5.7.6 and later #vi /etc/my.cnf basedir=/usr/local/mysql datadir=/usr/local/mysql/data skip-grant-tables --在my.cnf配置文件内添加skip-grant-tables跳过权限验证 #service mysqld restart --重启mysql服务 --直接输入mysql登录 [root@hisdb etc]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 7 Server version: 8.0.27 MySQL Community Server - GPL Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> --开始修改root密码