The cracklib_password_check
plugin was first released in MariaDB 10.1.2.
The plugin requires at least cracklib 2.9.0, so it is not available on Debian/Ubuntu builds before Debian 8 Jessie/Ubuntu 14.04 Trusty, RedHat Enterprise Linux / CentOS 6. (see MDEV-7305).
cracklib_password_check
is a password validation plugin. It uses the CrackLib library to check the strength of new passwords. CrackLib is installed by default in many Linux distributions, since the system's Pluggable Authentication Module (PAM) authentication framework is usually configured to check the strength of new passwords with the pam_cracklib
PAM module.
Note that passwords can be directly set as a hash, bypassing the password validation, if the strict_password_validation variable is OFF
(it is ON
by default).
The cracklib_password_check
plugin's shared library is included in MariaDB packages as the cracklib_password_check.so
or cracklib_password_check.dll
shared library on systems where it can be built. The plugin was first included in MariaDB 10.1.2.
The cracklib_password_check
plugin is included in systemd
binary tarballs on Linux, but not in the older generic and glibc_214
tarballs.
The cracklib_password_check
plugin can also be installed via a package manager on Linux. In order to do so, your system needs to be configured to install from one of the MariaDB repositories.
You can configure your package manager to install it from MariaDB Corporation's MariaDB Package Repository by using the MariaDB Package Repository setup script.
You can also configure your package manager to install it from MariaDB Foundation's MariaDB Repository by using the MariaDB Repository Configuration Tool.
On RHEL, CentOS, Fedora, and other similar Linux distributions, it is highly recommended to install the relevant RPM package from MariaDB's repository using yum
or dnf
. Starting with RHEL 8 and Fedora 22, yum
has been replaced by dnf
, which is the next major version of yum
. However, yum
commands still work on many systems that use dnf
. For example:
sudo yum install MariaDB-cracklib-password-check
On Debian, Ubuntu, and other similar Linux distributions, it is highly recommended to install the relevant DEB package from MariaDB's repository using apt-get
. For example:
sudo apt-get install mariadb-plugin-cracklib-password-check
On SLES, OpenSUSE, and other similar Linux distributions, it is highly recommended to install the relevant RPM package from MariaDB's repository using zypper
. For example:
sudo zypper install MariaDB-cracklib-password-check
Once the shared library is in place, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB.
The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing INSTALL SONAME
or INSTALL PLUGIN
. For example:
INSTALL SONAME 'cracklib_password_check';
The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the --plugin-load
or the --plugin-load-add
options. This can be specified as a command-line argument to mysqld
or it can be specified in a relevant server option group in an option file. For example:
[mariadb] ... plugin_load_add = cracklib_password_check
You can uninstall the plugin dynamically by executing UNINSTALL SONAME
or UNINSTALL PLUGIN
. For example:
UNINSTALL SONAME 'cracklib_password_check';
If you installed the plugin by providing the --plugin-load
or the --plugin-load-add
options in a relevant server option group in an option file, then those options should be removed to prevent the plugin from being loaded the next time the server is restarted.
If password validation fails, then the original CrackLib error message can be viewed by executing SHOW WARNINGS
.
When creating a new password, if the criteria are not met, the following error is returned:
SET PASSWORD FOR 'bob'@'%.loc.gov' = PASSWORD('abc'); ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
Prior to MariaDB 10.4.0, all password validation plugins are incompatible with the pam
authentication plugin. See Authentication Plugin - PAM: Conflicts with Password Validation for more information.
When using the standard SELinux policy with the mode set to enforcing
, mysqld
does not have access to /usr/share/cracklib
, and you may see the following error when attempting to use the cracklib_password_check
plugin:
CREATE USER `user`@`hostname` IDENTIFIED BY 's0mePwd123.'; ERROR 1819 (HY000): Your password does not satisfy the current policy requirements SHOW WARNINGS; +---------+------+----------------------------------------------------------------+ | Level | Code | Message | +---------+------+----------------------------------------------------------------+ | Warning | 1819 | cracklib: error loading dictionary | | Error | 1819 | Your password does not satisfy the current policy requirements | | Error | 1396 | Operation CREATE USER failed for 'user'@'hostname' | +---------+------+----------------------------------------------------------------+
And the SELinux audit.log
will contain errors like the following:
type=AVC msg=audit(1548371977.821:66): avc: denied { read } for pid=3537 comm="mysqld" name="pw_dict.pwd" dev="xvda2" ino=564747 scontext=system_u:system_r:mysqld_t:s0 tcontext=system_u:object_r:crack_db_t:s0 tclass=file type=SYSCALL msg=audit(1548371977.821:66): arch=c000003e syscall=2 success=no exit=-13 a0=7fdd2a674580 a1=0 a2=1b6 a3=1b items=0 ppid=1 pid=3537 auid=4294967295 uid=995 gid=992 euid=995 suid=995 fsuid=995 egid=992 sgid=992 fsgid=992 tty=(none) ses=4294967295 comm="mysqld" exe="/usr/sbin/mysqld" subj=system_u:system_r:mysqld_t:s0 key=(null)
This can be fixed by creating an SELinux policy that allows mysqld
to load the CrackLib dictionary. For example:
cd /usr/share/mysql/policy/selinux/ tee ./mariadb-plugin-cracklib-password-check.te <<EOF module mariadb-plugin-cracklib-password-check 1.0; require { type mysqld_t; type crack_db_t; class file { execute setattr read create getattr execute_no_trans write ioctl open append unlink }; class dir { write search getattr add_name read remove_name open }; } allow mysqld_t crack_db_t:dir { search read open }; allow mysqld_t crack_db_t:file { getattr read open }; EOF sudo yum install selinux-policy-devel make -f /usr/share/selinux/devel/Makefile mariadb-plugin-cracklib-password-check.pp sudo semodule -i mariadb-plugin-cracklib-password-check.pp
See MDEV-18374 for more information.
Version | Status | Introduced |
---|---|---|
1.0 | Stable | MariaDB 10.1.18 |
1.0 | Gamma | MariaDB 10.1.13 |
1.0 | Alpha | MariaDB 10.1.2 |
cracklib_password_check_dictionary
.hwm
, .pwd
, .pwi
), not a directory path. --cracklib-password-check-dictionary=value
string
/usr/share/cracklib/pw_dict
cracklib_password_check
OFF
- Disables the plugin without removing it from the mysql.plugins
table. ON
- Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. FORCE
- Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. FORCE_PLUS_PERMANENT
- Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with UNINSTALL SONAME
or UNINSTALL PLUGIN
while the server is running. --cracklib-password-check=value
enumerated
ON
OFF
, ON
, FORCE
, FORCE_PLUS_PERMANENT
© 2019 MariaDB
Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/cracklib_password_check/