mysql_no_login server-side authentication
plugin prevents all client connections to any account that uses
it. Use cases for this plugin include:
Accounts that must be able to execute stored programs and views with elevated privileges without exposing those privileges to ordinary users.
Proxied accounts that should never permit direct login but are intended to be accessed only through proxy accounts.
The following table shows the plugin and library file names. The
file name suffix might differ on your system. The file must be
located in the directory named by the
plugin_dir system variable.
Table 6.26 Plugin and Library Names for No-Login Authentication
|Plugin or File||Plugin or File Name|
The following sections provide installation and usage information specific to no-login pluggable authentication:
This section describes how to install the no-login authentication plugin. For general information about installing plugins, see Section 5.6.1, “Installing and Uninstalling Plugins”.
To be usable by the server, the plugin library file must be
located in the MySQL plugin directory (the directory named by
variable). If necessary, configure the plugin directory
location by setting the value of
plugin_dir at server startup.
The plugin library file base name is
mysql_no_login. The file name suffix
differs per platform (for example,
for Unix and Unix-like systems,
To load the plugin at server startup, use the
--plugin-load-add option to
name the library file that contains it. With this
plugin-loading method, the option must be given each time the
server starts. For example, put these lines in the server
my.cnf file, adjusting the
.so suffix for your platform as
my.cnf, restart the
server to cause the new settings to take effect.
Alternatively, to load the plugin at runtime, use this
statement, adjusting the
.so suffix for
your platform as necessary:
INSTALL PLUGIN mysql_no_login SONAME 'mysql_no_login.so';
INSTALL PLUGIN loads the plugin
immediately, and also registers it in the
mysql.plugins system table to cause the
server to load it for each subsequent normal startup without
the need for
To verify plugin installation, examine the Information Schema
PLUGINS table or use the
SHOW PLUGINS statement (see
Section 5.6.2, “Obtaining Server Plugin Information”). For example:
mysql> SELECT PLUGIN_NAME, PLUGIN_STATUS FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME LIKE '%login%'; +----------------+---------------+ | PLUGIN_NAME | PLUGIN_STATUS | +----------------+---------------+ | mysql_no_login | ACTIVE | +----------------+---------------+
If the plugin fails to initialize, check the server error log for diagnostic messages.
To associate MySQL accounts with the no-login plugin, see Using No-Login Pluggable Authentication.
The method used to uninstall the no-login authentication plugin depends on how you installed it:
If you installed the plugin at server startup using a
--plugin-load-addoption, restart the server without the option.
UNINSTALL PLUGIN mysql_no_login;
This section describes how to use the no-login authentication plugin to prevent accounts from being used for connecting from MySQL client programs to the server. It is assumed that the server is running with the no-login plugin enabled, as described in Installing No-Login Pluggable Authentication.
To refer to the no-login authentication plugin in the
IDENTIFIED WITH clause of a
CREATE USER statement, use the
An account that authenticates using
mysql_no_login may be used as the
DEFINER for stored program and view
objects. If such an object definition also includes
SQL SECURITY DEFINER, it executes with that
account's privileges. DBAs can use this behavior to provide
access to confidential or sensitive data that is exposed only
through well-controlled interfaces.
The following example illustrates these principles. It defines
an account that does not permit client connections, and
associates with it a view that exposes only certain columns of
mysql.user system table:
CREATE DATABASE nologindb; CREATE USER 'nologin'@'localhost' IDENTIFIED WITH mysql_no_login; GRANT ALL ON nologindb.* TO 'nologin'@'localhost'; GRANT SELECT ON mysql.user TO 'nologin'@'localhost'; CREATE DEFINER = 'nologin'@'localhost' SQL SECURITY DEFINER VIEW nologindb.myview AS SELECT User, Host FROM mysql.user;
To provide protected access to the view to an ordinary user, do this:
GRANT SELECT ON nologindb.myview TO 'ordinaryuser'@'localhost';
Now the ordinary user can use the view to access the limited information it presents:
SELECT * FROM nologindb.myview;
Attempts by the user to access columns other than those exposed by the view result in an error, as do attempts to select from the view by users not granted access to it.
nologin account cannot be
used directly, the operations required to set up objects
that it uses must be performed by
similar account that has the privileges required to create
the objects and set
mysql_no_login plugin is also useful in
proxying scenarios. (For a discussion of concepts involved in
proxying, see Section 6.2.19, “Proxy Users”.) An account that
mysql_no_login may be
used as a proxied user for proxy accounts:
-- create proxied account CREATE USER 'proxied_user'@'localhost' IDENTIFIED WITH mysql_no_login; -- grant privileges to proxied account GRANT ... ON ... TO 'proxied_user'@'localhost'; -- permit proxy_user to be a proxy account for proxied account GRANT PROXY ON 'proxied_user'@'localhost' TO 'proxy_user'@'localhost';
This enables clients to access MySQL through the proxy account
proxy_user) but not to bypass the proxy
mechanism by connecting directly as the proxied user
proxied_user). A client who connects using
proxy_user account has the privileges
proxied_user account, but
proxied_user itself cannot be used to
For alternative methods of protecting proxied accounts against direct use, see Preventing Direct Login to Proxied Accounts.