7.3.2 Password Validation Plugin Options and Variables

To control the activation of the validate_password plugin, use this option:

• --validate-password[=value]

  Introduced	5.6.6
  Command-Line Format	--validate-password[=value]
  Permitted Values	Type	enumeration
  	Default	ON
  	Valid Values	ON
  		OFF
  		FORCE
  		FORCE_PLUS_PERMANENT

  This option controls how the server loads the validate_password plugin at startup. The value should be one of those available for plugin-loading options, as described in Installing and Uninstalling Plugins. For example, --validate-password=FORCE_PLUS_PERMANENT tells the server to load the plugin at startup and prevents it from being removed while the server is running.

  This option is available only if the validate_password plugin has been previously registered with INSTALL PLUGIN or is loaded with --plugin-load-add. See Section 7.3.1, “Password Validation Plugin Installation”.

If the validate_password plugin is enabled, it exposes several system variables representing the parameters that control password checking:

mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| 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      |
+--------------------------------------+--------+

To change how passwords are checked, you can set these system variables at server startup or at runtime. The following list describes the meaning of each variable.

• validate_password_dictionary_file

  Introduced	5.6.6
  System Variable (<= 5.6.25)	Name	validate_password_dictionary_file
  	Variable Scope	Global
  	Dynamic Variable	No
  System Variable	Name	validate_password_dictionary_file
  	Variable Scope	Global
  	Dynamic Variable	No
  System Variable (>= 5.6.26)	Name	validate_password_dictionary_file
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	file name

  The path name of the dictionary file used by the validate_password plugin for checking passwords. This variable is unavailable unless that plugin is installed.

  By default, this variable has an empty value and dictionary checks are not performed. To enable dictionary checks, you must set this variable to a nonempty value. If the file is named as a relative path, it is interpreted relative to the server data directory. Its contents should be lowercase, one word per line. Contents are treated as having a character set of utf8. The maximum permitted file size is 1MB.

  For the dictionary file to be used during password checking, the password policy must be set to 2 (STRONG); see the description of the validate_password_policy system variable. Assuming that is true, each substring of the password of length 4 up to 100 is compared to the words in the dictionary file. Any match causes the password to be rejected. Comparisons are not case sensitive.

  For VALIDATE_PASSWORD_STRENGTH() the password is checked against all policies, including STRONG, so the strength assessment includes the dictionary check regardless of the validate_password_policy value.

  Before MySQL 5.6.26, changes to the dictionary file while the server is running require a restart for the server to recognize the changes. As of MySQL 5.6.26, validate_password_dictionary_file can be set at runtime and assigning a value causes the named file to be read without a restart.

• validate_password_length

  Introduced	5.6.6
  System Variable	Name	validate_password_length
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	integer
  	Default	8
  	Min Value	0

  The minimum number of characters that passwords checked by the validate_password plugin must have. This variable is unavailable unless that plugin is installed.

  The validate_password_length minimum value is a function of several other related system variables. As of MySQL 5.6.10, the server will not set the value less than the value of this expression:

  validate_password_number_count
  + validate_password_special_char_count
  + (2 * validate_password_mixed_case_count)

  If the validate_password plugin adjusts the value of validate_password_length due to the preceding constraint, it writes a message to the error log.

• validate_password_mixed_case_count

  Introduced	5.6.6
  System Variable	Name	validate_password_mixed_case_count
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	integer
  	Default	1
  	Min Value	0

  The minimum number of lowercase and uppercase characters that passwords checked by the validate_password plugin must have if the password policy is MEDIUM or stronger. For a given value, the password must have that many lowercase characters, and that many uppercase characters. This variable is unavailable unless that plugin is installed.

• validate_password_number_count

  Introduced	5.6.6
  System Variable	Name	validate_password_number_count
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	integer
  	Default	1
  	Min Value	0

  The minimum number of numeric (digit) characters that passwords checked by the validate_password plugin must have if the password policy is MEDIUM or stronger. This variable is unavailable unless that plugin is installed.

• validate_password_policy

  Introduced	5.6.6
  System Variable	Name	validate_password_policy
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	enumeration
  	Default	1
  	Valid Values	0
  		1
  		2

  The password policy enforced by the validate_password plugin. This variable is unavailable unless that plugin is installed.

  The validate_password_policy value can be specified using numeric values 0, 1, 2, or the corresponding symbolic values LOW, MEDIUM, STRONG. The following table describes the tests performed for each policy. For the length test, the required length is the value of the validate_password_length system variable. Similarly, the required values for the other tests are given by other validate_password_xxx variables.

  Policy	Tests Performed
  0 or LOW	Length
  1 or MEDIUM	Length; numeric, lowercase/uppercase, and special characters
  2 or STRONG	Length; numeric, lowercase/uppercase, and special characters; dictionary file

  Note

  Before MySQL 5.6.10, validate_password_policy was named validate_password_policy_number.

• validate_password_special_char_count

  Introduced	5.6.6
  System Variable	Name	validate_password_special_char_count
  	Variable Scope	Global
  	Dynamic Variable	Yes
  Permitted Values	Type	integer
  	Default	1
  	Min Value	0

  The minimum number of nonalphanumeric characters that passwords checked by the validate_password plugin must have if the password policy is MEDIUM or stronger. This variable is unavailable unless that plugin is installed.

If the validate_password plugin is enabled, it exposes status variables that provide operational information:

mysql> SHOW STATUS LIKE 'validate_password%';
+-----------------------------------------------+---------------------+
| Variable_name                                 | Value               |
+-----------------------------------------------+---------------------+
| validate_password_dictionary_file_last_parsed | 2015-06-29 11:08:51 |
| validate_password_dictionary_file_words_count | 1902                |
+-----------------------------------------------+---------------------+

The following list describes the meaning of each status variable.

• validate_password_dictionary_file_last_parsed

  When the dictionary file was last parsed.

  This variable was added in MySQL 5.6.26.

• validate_password_dictionary_file_words_count

  The number of words read from the dictionary file.

  This variable was added in MySQL 5.6.26.