防止使用過於簡單的密碼，mysql提供了validate_password密碼插件來強制規範密碼複雜度。用了這個插件再去創建123456這種密碼時操作會報錯。
https://dev.mysql.com/doc/refman/5.7/en/validate-password-installation.html
在線安裝：
INSTALL PLUGIN validate_password SONAME 'validate_password.so';
或者增加配置然後重啓
[mysqld]
plugin-load-add=validate_password.so
show plugins;查看下剛剛安裝的validate_password插件
(root@localhost) [(none)]>show plugins;
+----------------------------+----------+--------------------+----------------------+---------+
| Name | Status | Type | Library | License |
+----------------------------+----------+--------------------+----------------------+---------+
| binlog | ACTIVE | STORAGE ENGINE | NULL | GPL |
| mysql_native_password | ACTIVE | AUTHENTICATION | NULL | GPL |
| sha256_password | ACTIVE | AUTHENTICATION | NULL | GPL |
| CSV | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL |
| InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL |
| INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_LOCKS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_LOCK_WAITS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMPMEM | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMPMEM_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_PER_INDEX | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_CMP_PER_INDEX_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_PAGE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_PAGE_LRU | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_BUFFER_POOL_STATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_TEMP_TABLE_INFO | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_METRICS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_DEFAULT_STOPWORD | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_BEING_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_CONFIG | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_INDEX_CACHE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_FT_INDEX_TABLE | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLESTATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_INDEXES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_COLUMNS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FIELDS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FOREIGN | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_FOREIGN_COLS | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_TABLESPACES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_DATAFILES | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| INNODB_SYS_VIRTUAL | ACTIVE | INFORMATION SCHEMA | NULL | GPL |
| MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
| PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | GPL |
| ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| FEDERATED | DISABLED | STORAGE ENGINE | NULL | GPL |
| partition | ACTIVE | STORAGE ENGINE | NULL | GPL |
| ngram | ACTIVE | FTPARSER | NULL | GPL |
| validate_password | ACTIVE | VALIDATE PASSWORD | validate_password.so | GPL |
+----------------------------+----------+--------------------+----------------------+---------+
45 rows in set (0.00 sec)
查看參數 show variables like 'validate%';
(root@localhost) [(none)]>show variables like 'validate%';
+--------------------------------------+--------+
| 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 (0.01 sec)
1、validate_password_length 8 密碼長度爲8位
2、validate_password_mixed_case_count 1 包含一個大寫字母
3、validate_password_number_count 1 包含一個數字
4、validate_password_special_char_count 包含一個特殊字符
完了之後修改密碼爲123，報錯如下。密碼不安全，不符合validate_password插件的約束。
(root@localhost) [(none)]>alter user david@'%' identified by '123';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
那麼我們設置一個符合規範的密碼，設置成功
(root@localhost) [(none)]>alter user david@'%' identified by '1111aaA_';
Query OK, 0 rows affected (0.00 sec)
validate_password_dictionary_file 密碼字典表
啓用這個密碼字典表可以做到限制密碼不能包含字典中指定的字符串。
創建一個包含admin字符串的文件：
echo 'admin'> dic.file
指定validate_password_dictionary_file和validate_password_policy 值
(root@localhost) [(none)]>set global validate_password_dictionary_file = '/mdata/mysql57/dic.file';
Query OK, 0 rows affected (0.00 sec)
(root@localhost) [(none)]>set global validate_password_policy = STRONG;
Query OK, 0 rows affected (0.00 sec)
現在設置密碼爲1111adminDD_提示修改失敗。去掉admin使用kk代替就成功了。
(root@localhost) [(none)]>alter user david@'%' identified by '1111adminDD_';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
(root@localhost) [(none)]>alter user david@'%' identified by '1111kkDD_';
Query OK, 0 rows affected (0.00 sec)
validate_password_check_user_name
設置ON，約束密碼不能直接設置爲用戶名
set global validate_password_check_user_name= ON;
(root@localhost) [(none)]>alter user david@'%' identified by 'root';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements