錯誤信息
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
爲了加強安全性,MySQL5.7爲root用戶隨機生成了一個密碼,在error log中,關於error log的位置,如果安裝的是RPM包,則默認是/var/log/mysqld.log。
可通過# grep "password" /var/log/mysqld.log
命令獲取MySQL的臨時密碼
2016-01-19T05:16:36.218234Z 1 [Note] A temporary password is generated for root@localhost: waQ,qR%be2(5
用該密碼登錄到服務端後,必須馬上修改密碼,不然會報如下錯誤:
mysql> select user();
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
如果只是修改爲一個簡單的密碼,會報以下錯誤:
mysql> ALTER USER USER() IDENTIFIED BY '12345678';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
這個其實與validate_password_policy的值有關。
validate_password_policy有以下取值:
默認是1,即MEDIUM,所以剛開始設置的密碼必須符合長度,且必須含有數字,小寫或大寫字母,特殊字符。
有時候,只是爲了自己測試,不想密碼設置得那麼複雜,譬如說,我只想設置root的密碼爲123456。
必須修改兩個全局參數:
首先,修改validate_password_policy參數的值
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
這樣,判斷密碼的標準就基於密碼的長度了。這個由validate_password_length參數來決定。
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 8 |
+----------------------------+
1 row in set (0.00 sec)
validate_password_length參數默認爲8,它有最小值的限制,最小值爲:
validate_password_number_count
+ validate_password_special_char_count
+ (2 * validate_password_mixed_case_count)
其中,validate_password_number_count指定了密碼中數據的長度,validate_password_special_char_count指定了密碼中特殊字符的長度,validate_password_mixed_case_count指定了密碼中大小字母的長度。
這些參數,默認值均爲1,所以validate_password_length最小值爲4,如果你顯性指定validate_password_length的值小於4,儘管不會報錯,但validate_password_length的值將設爲4。如下所示:
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 8 |
+----------------------------+
1 row in set (0.00 sec)
mysql> set global validate_password_length=1;
Query OK, 0 rows affected (0.00 sec)
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 4 |
+----------------------------+
1 row in set (0.00 sec)
如果修改了validate_password_number_count,validate_password_special_char_count,validate_password_mixed_case_count中任何一個值,則validate_password_length將進行動態修改。
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 4 |
+----------------------------+
1 row in set (0.00 sec)
mysql> select @@validate_password_mixed_case_count;
+--------------------------------------+
| @@validate_password_mixed_case_count |
+--------------------------------------+
| 1 |
+--------------------------------------+
1 row in set (0.00 sec)
mysql> set global validate_password_mixed_case_count=2;
Query OK, 0 rows affected (0.00 sec)
mysql> select @@validate_password_mixed_case_count;
+--------------------------------------+
| @@validate_password_mixed_case_count |
+--------------------------------------+
| 2 |
+--------------------------------------+
1 row in set (0.00 sec)
mysql> select @@validate_password_length;
+----------------------------+
| @@validate_password_length |
+----------------------------+
| 6 |
+----------------------------+
1 row in set (0.00 sec)
當然,前提是validate_password插件必須已經安裝,MySQL5.7是默認安裝的。
那麼如何驗證validate_password插件是否安裝呢?可通過查看以下參數,如果沒有安裝,則輸出將爲空。
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------+-------+
| validate_password_dictionary_file | |
| validate_password_length | 6 |
| validate_password_mixed_case_count | 2 |
| validate_password_number_count | 1 |
| validate_password_policy | LOW |
| validate_password_special_char_count | 1 |
+--------------------------------------+-------+
6 rows in set (0.00 sec)