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  • MySQL 8.0权限认证(上)

    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
     
    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,'xjp');
    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,'xjp');
    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 | xjp  |
    |    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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  • 原文地址:https://www.cnblogs.com/xuewenlong/p/12882054.html
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