validate_password plugin (available as of
MySQL 5.6.6) can be used to test passwords and improve security.
This plugin implements two capabilities:
In statements that assign a password supplied as a cleartext
value, the value is checked against the current password
policy and rejected if it is weak (the statement returns an
error). This affects the
SET PASSWORD statements.
Passwords given as arguments to the
OLD_PASSWORD() functions are
checked as well.
The strength of potential passwords can be assessed using
SQL function, which takes a password argument and returns an
integer from 0 (weak) to 100 (strong).
For example, the cleartext password in the following statement is checked. Under the default password policy, which requires passwords to be at least 8 characters long, the password is weak and the statement produces an error:
SET PASSWORD = PASSWORD('abc');ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
Passwords specified as already hashed values are not checked because the original password value is not available:
SET PASSWORD = '*0D3CED9BEC10A777AEC23CCC353A8C08A633045E';Query OK, 0 rows affected (0.01 sec)
The parameters that control password checking are available as
the values of the system variables having names of the form
These variables can be modified to configure password checking;
see Section 220.127.116.11, “Password Validation Plugin Options and Variables”.
The three levels of password checking are
STRONG. The default is
MEDIUM; to change this, modify the value of
policies implement increasingly strict password tests. The
following descriptions refer to default parameter values; these
can be modified by changing the appropriate system variables.
LOW policy tests password length only.
Passwords must be at least 8 characters long.
MEDIUM policy adds the conditions that
passwords must contain at least 1 numeric character, 1
lowercase and uppercase character, and 1 special
STRONG policy adds the condition that
password substrings of length 4 or longer must not match
words in the dictionary file, if one has been specified.
validate_password plugin is not
system variables are not available, passwords in statements are
not checked, and
always returns 0. For example, accounts can be assigned
passwords shorter than 8 characters.