MySQL 5.7 學習心得之安全相關特性_MySQL

1,賬號安全相關的特性

1.1:創建用戶

5.7版本的用戶表mysql.user要求plugin字段非空,且默認值是mysql_native_password認證插件,并且不再支持mysql_old_password認證插件。5.7用戶長度最大為32字節,之前最大長度為16字節,并且CREATE USER 和 DROP USER 命令里實現了 IF [NOT] EXISTS 條件判斷。5.7之后用戶通過grant創建用戶報warning。如:

 grant all on *.* to dxy@localhost identified by 'dxy'; Query OK, 0 rows affected, 1 warnings (0.00 sec) show warnings; +---------+------+---------------------------------------------------------------+ | Level | Code | Message | +---------+------+---------------------------------------------------------------+ | Warning | 1287 | Using GRANT for creating new user is deprecated and will be removed in future release. Create new user with CREATE USER statement. | +---------+------+---------------------------------------------------------------+ 2 rows in set (0.01 sec)

提示grant創建賬戶的語法將會被刪除,用cerate user代替,創建用戶分2步:創建和授權。

先通過create user 創建用戶:

 #明文密碼創建 CREATE USER 'dxy'@'localhost' IDENTIFIED BY '123456';等同 CREATE USER 'dxy'@'localhost' IDENTIFIED WITH 'mysql_native_password' BY '123456'; #加密密碼創建 CREATE USER 'dxy'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9'; --will be removed in a future release等同 CREATE USER 'dxy'@'localhost' IDENTIFIED WITH 'mysql_native_password' AS '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9';

再通過grant來授權:

 grant select,insert,update,delete on dba_test.* to dxy@localhost;

注意:授權管理用戶的時候,不止只有all的權限,還要包括with grant option和proxy的權限。proxy權限需要在代理用戶的時候用到。

 查看默認管理用戶權限: show grants for root@localhost; ----2條記錄 +---------------------------------------------------------------------+ | +---------------------------------------------------------------------+ | GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION | | GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION | +---------------------------------------------------------------------+ 新建管理賬號: create user dba@127.0.0.1 identified by '123456'; 授權: GRANT ALL PRIVILEGES ON *.* TO 'root'@'127.0.0.1' WITH GRANT OPTION; 授proxy權:創建代理用戶的時候需要 GRANT PROXY ON ''@'' TO 'dba'@'127.0.0.1' WITH GRANT OPTION; 查看: show grants for 'dba'@'127.0.0.1'; +--------------------------------------------------------------------+ | GRANT ALL PRIVILEGES ON *.* TO 'dba'@'127.0.0.1' WITH GRANT OPTION | | GRANT PROXY ON ''@'' TO 'dba'@'127.0.0.1' WITH GRANT OPTION | +--------------------------------------------------------------------+

查看用戶權限:

 show grants for dxy@localhost; +---------------------------------------------------------------------------+ | Grants for dxy@localhost | +---------------------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'dxy'@'localhost' | | GRANT SELECT, INSERT, UPDATE, DELETE ON `dba_test`.* TO 'dxy'@'localhost' | +---------------------------------------------------------------------------+

查看用戶密碼:

 show create user dxy@localhost; +----------------------------------------------------------------------------------+ | CREATE USER 'dxy'@'localhost' IDENTIFIED WITH 'mysql_native_password' AS '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK | +----------------------------------------------------------------------------------+

1.2:密碼過期策略

為用戶設置密碼過期時間,一定時間以后,強制用戶修改密碼。可以直接在create user的時候設置,也可以alter user設置:

PASSWORD EXPIRE DEFAULT   默認,過期時間受全局變量default_password_lifetime控制
PASSWORD EXPIRE NEVER 永不過期
PASSWORD EXPIRE INTERVAL N DAY   N天后過期
PASSWORD EXPIRE 過期

直接創建用戶的時候設置:

 create user dxy@localhost identified by '123456' password expire interval 10 day; ---- 10天后過期

對已有用戶設置

 alter user zjy@localhost password expire never; ----永不過期

注意:設置一個用戶過期后,登陸會有提示修改密碼,不能進行任何操作:適用讓程序不能訪問數據庫。

設置用戶密碼過期:

 alter user dxy@localhost password expire;

執行任何命令報錯:

 ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

解決辦法:重置密碼 alter user dxy@localhost identified by ‘123456’;

1.3:鎖定禁用用戶 alter user

當某些場景需要”鎖”住用戶,暫時禁用某個用戶:適用讓程序不能訪問數據庫。

設置鎖定用戶:

 alter user dxy@localhost account lock;

登陸報錯:

 ERROR 3118 (HY000): Access denied for user 'dxy'@'localhost'. Account is locked.

解決辦法:解鎖用戶

 alter user dxy@localhost account unlock;

1.4 代理用戶

基于mysql_native_password的認證插件自帶了代理用戶的功能。代理用戶相當于“代理”其他用戶的權限,這樣很方便的把一個賬號的權限授予其他賬號,而不需要每個賬號都需要執行授權操作。開啟代理用戶的功能需要開啟參數:check_proxy_users 和 mysql_native_password_proxy_users

創建原始賬號:

 create user dxy@127.0.0.1 identified by '123456';

授權:

 grant all on test.* to dxy@127.0.0.1;

創建代理賬號:

 create user dxy_proxy@127.0.0.1 identified by '123456';

授權代理權限:

 grant proxy on dxy@127.0.0.1 to dxy_proxy@127.0.0.1;

查看:

 show grants for dxy_proxy@127.0.0.1; +-------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'dxy_proxy'@'127.0.0.1' | | GRANT PROXY ON 'dxy'@'127.0.0.1' TO 'dxy_proxy'@'127.0.0.1' | +-------------------------------------------------------------+

用代理賬號登陸測試:

查看登陸賬號:代理賬號current_user(),原始賬號user()

 select user(),current_user(); +---------------------+----------------+ | user() | current_user() | +---------------------+----------------+ | dxy_proxy@127.0.0.1 | dxy@127.0.0.1 | +---------------------+----------------+

查看權限:發現代理賬號的權限顯示的是原始賬號的權限

 show grants;+-------------------------------------------------------+ +-------------------------------------------------------+ | GRANT USAGE ON *.* TO 'dxy'@'127.0.0.1' | | GRANT ALL PRIVILEGES ON `test`.* TO 'dxy'@'127.0.0.1' | +-------------------------------------------------------+

驗證代理賬號是否有test庫的權限:

 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | test | +--------------------+ mysql> use test mysql> show tables; +----------------+ | Tables_in_test | +----------------+ | tttt | +----------------+ mysql> select * from tttt; +------+ | id | +------+ | 1 | | 100 | +------+ mysql> insert into tttt values(2),(200); mysql> select * from tttt; +------+ | id | +------+ | 1 | | 100 | | 2 | | 200 | +------+

驗證得出代理賬號(dxy_proxy)代理了原始賬號(dxy)的權限。

1.5:其他選項:SSL、MAX_QUERIES_PER_HOUR、MAX_UPDATES_PER_HOUR、MAX_CONNECTIONS_PER_HOUR、MAX_USER_CONNECTIONS。當需要限制賬號通過ssl登陸,需要添加require,當需要限制資源,需要添加with:

 create user dxy@localhost identified by '123456' require SSL with MAX_QUERIES_PER_HOUR 100 MAX_USER_CONNECTIONS 100 password expire never account unlock;

2,外部相關的安全

2.1:MySQL5.7已經刪除了test數據庫,默認安裝完后是沒有test數據庫,原先任何用戶都可以訪問test數據庫,增加安全隱患。

2.2:MySQL5.7提供了更為簡單SSL安全訪問配置,并且默認連接就采用SSL的加密方式。在5.7之前,生成SSL相關文件需要自己手動創建,可以查看這篇文章,5.7之后MySQL通過

mysql_ssl_rsa_setup可以直接生成了:

 root@t20:~# mysql_ssl_rsa_setup  Generating a 2048 bit RSA private key .................................+++ ....................+++ writing new private key to 'ca-key.pem' ----- Generating a 2048 bit RSA private key ......+++ ..............................+++ writing new private key to 'server-key.pem' ----- Generating a 2048 bit RSA private key .........................................................................................+++ ..+++ writing new private key to 'client-key.pem' -----

可以在數據目錄下面看到一些以pem結尾的文件,而這些文件就是開啟SSL連接所需要的文件(注意文件權限),之后用賬號

默認登陸:

 root@t20:/var/lib/mysql# mysql -udba -p -h127.0.0.1 Enter password:  mysql> s -------------- mysql Ver 14.14 Distrib 5.7.12, for Linux (x86_64) using EditLine wrapper Connection id: 4 Current database:  Current user: dba@localhost SSL: Cipher in use is DHE-RSA-AES256-SHA ... ...

強制ssl登陸:

 root@t20:~# mysql -udba -p -h127.0.0.1 --ssl=1  WARNING: --ssl is deprecated and will be removed in a future version. Use --ssl-mode instead. Enter password:  mysql> s -------------- mysql Ver 14.14 Distrib 5.7.12, for Linux (x86_64) using EditLine wrapper Connection id: 10 Current database:  Current user: dba@localhost SSL: Cipher in use is DHE-RSA-AES256-SHA ... ...

從上面看到均已ssl登陸,若在創建用戶時,希望該用戶每次必須通過SSL方式,則需在創建用戶通過REQUIRE SSL來進行設置,上面已經介紹。姜承堯文章中的測試案例顯示開啟SSL性能開銷在25%左右:MySQL的SSL加密連接與性能開銷

2.3:MySQL5.7開始建議用戶使用 mysqld –initialize來初始化數據庫,放棄之前的mysql_install_db的方式,新的方式只創建了一個root@localhost的用戶,隨機密碼保存在~/.mysql_secret文件中,第一次使用必須reset password。

初始化數據庫:新建實例。

mysqld –initialize –datadir=/var/lib/mysql3309/

2.4:MySQL5.7 sql_mode的變更,

5.7默認的sql_mode

select @@sql_mode;
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

5.7之前默認的sql_mode

select @@sql_mode;
NO_ENGINE_SUBSTITUTION

看到在5.7中sql_mode更加嚴格。解釋下各個mode的含義:

ONLY_FULL_GROUP_BY  

不要讓GROUP BY部分中的查詢指向未選擇的列  

STRICT_TRANS_TABLES

為事務存儲引擎啟用嚴格模式,也可能為非事務存儲引擎啟用嚴格模式
NO_ZERO_IN_DATE 在嚴格模式,不接受月或日部分為0的日期
NO_ZERO_DATE 在嚴格模式,不將 ‘0000-00-00’做為合法日期
ERROR_FOR_DIVISION_BY_ZERO 在嚴格模式,在INSERT或UPDATE過程中,如果被零除(或MOD(X,0)),則產生錯誤  
NO_AUTO_CREATE_USER 防止GRANT自動創建新用戶,除非還指定了密碼
NO_ENGINE_SUBSTITUTION 如果需要的存儲引擎被禁用或未編譯,可以防止自動替換存儲引擎

在默認情況下5.7的情況:

 ----對于datetime類型<no_zero_date>: 插入"0000-00-00 00:00:00"值,會報錯:Incorrect datetime value ----對于varchar/char類型<strict_trans_tables>: 插入字符串超出長度,會報錯: Data too long for column... ----對于not null的列<strict_trans_tables>: 插入不指定not null的列會報錯:Field 'xxx' doesn't have a default value '  ----對于grant<no_auto_create_user>: 授權一個用戶,不指定密碼會報錯:Can't find any matching row in the user table ' ----對于engine存儲引擎<no_engine_substitution>: 創建一個不支持的存儲引擎,不會轉換為默認的存儲引擎,直接報錯:Unknown storage engine ... Using storage engine InnoDB for table '...'</no_engine_substitution></no_auto_create_user></strict_trans_tables></strict_trans_tables></no_zero_date>

注意:在一個主從環境下,為保證數據的一致性,一定要設置主從的sql_mode一樣,在數據遷移的時候也要保證sql_mode的一致,不然復制和遷移遇到上面的限制均會失敗,所以盡可能使用標準SQL語法。

3,總結:

在MySQL 5.7中,有不少安全性相關的改進:創建賬號分2步:用create user來建立賬號(賬號長度加大),用grant 來授權;初始數據庫的時候密碼不為空;賬號可以鎖和可以設置密碼過期;test庫被刪除;默認提供ssl連接;sql_mode增強等。文章從這些方面進行了介紹和測試,進一步加深對MySQL5.7的認識。

以上所述是小編給大家介紹的MySQL 5.7 學習心得之安全相關特性,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對網站的支持!

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