As of MySQL 5.5.16, commercial distributions of MySQL include an authentication plugin that enables MySQL Server to use PAM (Pluggable Authentication Modules) to authenticate MySQL users. PAM enables a system to use a standard interface to access various kinds of authentication methods, such as Unix passwords or an LDAP directory.

The PAM plugin uses the information passed to it by MySQL Server (such as user name, host name, password, and authentication string), plus whatever method is available for PAM lookup. The plugin checks the user credentials against PAM and returns 'Authentication succeeded, Username is user_name' or 'Authentication failed'.

The PAM authentication plugin provides these capabilities:

The following table shows the plugin and library file names. The file name suffix might be different on your system. The file location must be the directory named by the plugin_dir system variable. For installation information, see Section 5.6.2.1, “Installing the PAM Authentication Plugin”.

The library file includes only the server-side plugin. As of MySQL 5.5.10, the client-side plugin is built into the libmysqlclient client library. See Section 5.6.4, “The Cleartext Client-Side Authentication Plugin”.

The server-side PAM authentication plugin is included only in commercial distributions. It is not included in MySQL community distributions. The client-side clear-text plugin that communicates with the server-side plugin is built into the MySQL client library and is included in all distributions, including community distributions. This permits clients from any 5.5.10 or newer distribution to connect to a server that has the server-side plugin loaded.

The PAM authentication plugin has been tested on Linux and Mac OS X. It requires MySQL Server 5.5.16 or newer.

For general information about pluggable authentication in MySQL, see Section 5.6, “Pluggable Authentication”. For proxy user information, see Section 5.7, “Proxy Users”.