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MySQL 8.0授权认证
 

一.系统权限表

 
user
存放用户账户信息以及全局级别(所有数据库)权限,决定了来自哪些主机的哪些用户可以访问数据库实例,如果有全局权限则意味着对所有数据库都有此权限
db
存放数据库级别的权限,决定了来自哪些主机的哪些用户可以访问此数据库
tables_priv
存放表级别的权限,决定了来自哪些主机的哪些用户可以访问数据库的这个表
columns_priv
存放列级别的权限,决定了来自哪些主机的哪些用户可以访问数据库表的这个字段
procs_priv
存放存储过程和函数级别的权限
 

二.创建用户与授权

 

1.简单的例子

#创建用户
#重点:用户创建完成可以连接,但是没有任何权限
create user hans@localhost identified by \'123456\';
#授权
#这个就相当于给了一个超级管理员权限
grants all on *.* to \'hans\'@\'localhost\';
#查看用户的权限
show grants for hans@localhost;
#如果权限过大,那就回收权限
revoke all on *.* from \'hans\'@\'localhost\';

 

 

2.关于远程用户

#这是配置远程用户和权限
可以用%来表示允许所有的IP进行连接 比如\'hans\'@\'%\'
grants all on *.* to \'hans\'@\'192.168.1.%\'
可以用192.168.1.%来表示 192.168.1.0/24这个网段的IP来进行连接 比如 \'hans\'@\'192.168.1.%
grants select on *.* to \'hans\'@\'192.168.1.%
可以用192.168.1.%来表示 192.168.1.0/24这个网段的IP来进行连接 比如 \'hans\'@\'192.168.1.10%\'
grants insert,update,delete on *.* to \'hans\'@\'192.168.1.10%
#重点 这个带网段的这个权限会是叠加的

 

 

3.复杂的例子

案例1
#你的网段可能不是10.0.0.0/8,这不重要,重要的是你可以领会这个权限操作
(1)
来自企业内网10.0.0网段的应用程序app1希望能赋予MySQL数据库实例里的
A1数据库的增删改查权限,
A2数据库里B2表的查询权限,
A3数据库B3表上ID字段的查询权限,
这个数据库用户的创建语句是什么?
(2)
如果要回收该用户在A2数据库里B2表的查询权限,语句怎么写?
 
create user \'app1\'@\'10.0.0.%\' identified by \'123456\';
grant select,instert,update,delete on a1.* to \'app1\'@\'10.0.0.%\';
grant select on a2.b2 to \'app1\'@\'10.0.0.%\';
grant select(id) on a3.b3 to \'app1\'@\'10.0.0.%\';

 

 
这个复杂的例子就是把MySQL权限认证操作写的更细致,控制的粒度控制到了字段(列)级别
那么如何验证上面的授权语句是否正确呢?
通过查询MySQL的系统权限表,就可以知道对这个用户的权限配置
 
我一步一步演示上面的这个复杂的案例
先完成(1)

创建3个数据库

mysql> create database a1;
Query OK, 1 row affected (0.11 sec)
 
mysql> create database a2;
Query OK, 1 row affected (0.04 sec)
 
mysql> create database a3;
Query OK, 1 row affected (0.05 sec)

 

 
创建表
mysql> use a1;
Database changed
mysql> create table t1 (sid int,name varchar(10));
Query OK, 0 rows affected (0.10 sec)
 
mysql> use a2;
Database changed
mysql> create table b2 (sid int,name varchar(10));
Query OK, 0 rows affected (0.06 sec)
 
mysql> use a3;
Database changed
mysql> create table b3 (sid int,name varchar(10));
Query OK, 0 rows affected (0.41 sec)

 

 
创建app1这个用户
mysql> create user \'app1\'@\'192.168.91.%\' identified by \'123456!\';
Query OK, 0 rows affected (0.08 sec)

 

 

授权

mysql> grant select,insert,update,delete on a1.* to \'app1\'@\'192.168.91.%\';
Query OK, 0 rows affected (0.08 sec)
 
mysql> grant select on a2.b2 to \'app1\'@\'192.168.91.%\';
Query OK, 0 rows affected (0.09 sec)
 
mysql> grant select(sid) on a3.b3 to \'app1\'@\'192.168.91.%\';
Query OK, 0 rows affected (0.04 sec)

 

 

验证

这个是数据库级别
mysql>  select * from mysql.db where user=\'app1\' and host=\'192.168.91.%\'\G;
*************************** 1. row ***************************
                 Host: 192.168.91.%
                   Db: a1
                 User: app1
          Select_priv: Y
          Insert_priv: Y
          Update_priv: Y
          Delete_priv: Y
          Create_priv: N
            Drop_priv: N
           Grant_priv: N
      References_priv: N
           Index_priv: N
           Alter_priv: N
Create_tmp_table_priv: N
     Lock_tables_priv: N
     Create_view_priv: N
       Show_view_priv: N
  Create_routine_priv: N
   Alter_routine_priv: N
         Execute_priv: N
           Event_priv: N
         Trigger_priv: N
1 row in set (0.00 sec)
 
ERROR:
No query specified

 

 
这个是表级别
mysql> select * from mysql.tables_priv where user=\'app1\' and host=\'192.168.91.%\'\G;
*************************** 1. row ***************************
       Host: 192.168.91.%
         Db: a2
       User: app1
 Table_name: b2
    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv: Select
Column_priv:
*************************** 2. row ***************************
       Host: 192.168.91.%
         Db: a3
       User: app1
 Table_name: b3
    Grantor: root@localhost
  Timestamp: 0000-00-00 00:00:00
 Table_priv:
Column_priv: Select
2 rows in set (0.00 sec)
 
ERROR:
No query specified

 

 

这个就是字段(列)级别

mysql> select * from mysql.columns_priv where user=\'app1\' and host=\'192.168.91.%\'\G;
*************************** 1. row ***************************
       Host: 192.168.91.%
         Db: a3
       User: app1
 Table_name: b3
Column_name: sid
  Timestamp: 0000-00-00 00:00:00
Column_priv: Select
1 row in set (0.00 sec)
 
ERROR:
No query specified

 

 
换个语句再看下用户的权限
mysql> show grants for \'app1\'@\'192.168.91.%\'\G;
*************************** 1. row ***************************
Grants for app1@192.168.91.%: GRANT USAGE ON *.* TO `app1`@`192.168.91.%`
*************************** 2. row ***************************
Grants for app1@192.168.91.%: GRANT SELECT, INSERT, UPDATE, DELETE ON `a1`.* TO `app1`@`192.168.91.%`
*************************** 3. row ***************************
Grants for app1@192.168.91.%: GRANT SELECT ON `a2`.`b2` TO `app1`@`192.168.91.%`
*************************** 4. row ***************************
Grants for app1@192.168.91.%: GRANT SELECT (`sid`) ON `a3`.`b3` TO `app1`@`192.168.91.%`
4 rows in set (0.00 sec)
 
ERROR:
No query specified

 

 

三 客户端验证

#我这里再找1台1同网段的虚拟机安装mysql客户端做测试,这里安装的是mariadb的客户端,远程连接数据库服务器
#这里数据库a1我就不做测试了,直接从a2开始
 
[root@localhost ~]# mysql -u app1 -h192.168.91.128 -p
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 8.0.13 MySQL Community Server - GPL
 
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
 
Type \'help;\' or \'\h\' for help. Type \'\c\' to clear the current input statement.
 
MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| a1                 |
| a2                 |
| a3                 |
| information_schema |
+--------------------+
4 rows in set (0.00 sec)
 
 
MySQL [(none)]> use a2;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
MySQL [a2]> insert into a2 (sid,name) values (1,\'***\');
ERROR 1142 (42000): INSERT command denied to user \'app1\'@\'192.168.91.129\' for table \'a2\'

 

#这里就说明了没有insert权限
 
#测试a3,我们需要用root用户插入数据,我们再用app1用户做测试
mysql> use a3;
Database changed
mysql> show tables;
+--------------+
| Tables_in_a3 |
+--------------+
| b3           |
+--------------+
1 row in set (0.00 sec)
 
mysql> insert into b3 (sid,name) values (1,\'***\');
Query OK, 1 row affected (0.07 sec)
 
mysql> insert into b3 (sid,name) values (2,\'mzd\');
Query OK, 1 row affected (0.01 sec)
 
mysql> select * from b3;
+------+------+
| sid  | name |
+------+------+
|    1 | ***  |
|    2 | mzd  |
+------+------+
2 rows in set (0.00 sec)

 

 
#OK,这里我们插入了2条数据,这里的需求是a3数据库b3表上sid字段的查询权限,那我们就做如下的测试
用客户端登录
MySQL [(none)]> use a3;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
MySQL [a3]> show tables;
+--------------+
| Tables_in_a3 |
+--------------+
| b3           |
+--------------+
1 row in set (0.00 sec)
 
MySQL [a3]> select * from b3;
ERROR 1142 (42000): SELECT command denied to user \'app1\'@\'192.168.91.129\' for table \'b3\'
MySQL [a3]> select name from b3;
ERROR 1143 (42000): SELECT command denied to user \'app1\'@\'192.168.91.129\' for column \'name\' in table \'b3\'

 

看到了吧!不给查,被拒绝了,那我们只查sid再试一次
MySQL [a3]> select sid from b3;
+------+
| sid  |
+------+
|    1 |
|    2 |
+------+
2 rows in set (0.00 sec

 


看到了吧!奇迹出现了!
 
(2)如果要回收该用户在a2数据库里b2表的查询权限,语句怎么写?
mysql> revoke select on a2.b2 from \'app1\'@\'192.168.91.%\';
Query OK, 0 rows affected (0.07 sec)

 

 
那我们再看下权限
mysql> show grants for \'app1\'@\'192.168.91.%\'\G;
*************************** 1. row ***************************
Grants for app1@192.168.91.%: GRANT USAGE ON *.* TO `app1`@`192.168.91.%`
*************************** 2. row ***************************
Grants for app1@192.168.91.%: GRANT SELECT, INSERT, UPDATE, DELETE ON `a1`.* TO `app1`@`192.168.91.%`
*************************** 3. row ***************************
Grants for app1@192.168.91.%: GRANT SELECT (`sid`) ON `a3`.`b3` TO `app1`@`192.168.91.%`
3 rows in set (0.00 sec)
 
ERROR:
No query specified

 

我们发现a2.b2没有读的权限了
我们用客户端验证下
[root@localhost ~]# mysql -u app1 -h192.168.91.128 -p
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 21
Server version: 8.0.13 MySQL Community Server - GPL
 
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
 
Type \'help;\' or \'\h\' for help. Type \'\c\' to clear the current input statement.
 
MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| a1                 |
| a3                 |
| information_schema |
+--------------------+
3 rows in set (0.00 sec)
 

 

是的,你没看错,a2连看都看不到了
我强制试试
MySQL [(none)]> use a2;
ERROR 1044 (42000): Access denied for user \'app1\'@\'192.168.91.%\' to database \'a2\'

 

看到了吧,权限直接拒绝了

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