@Override
    public String getServerKey(String username) throws UnsupportedOperationException, UserNotFoundException {
        throw new UnsupportedOperationException();
    }
Authenticates using the native operating system authentication method. On Windows,
this means Win32 authentication; on Unix/Linux, PAM authentication. New user accounts
will be created automatically as needed.<p>

Authentication is handled using the <a href="http://opensource.cenqua.com/shaj">Shaj</a>
library. In order for this provider to work, the appropriate native library must be loaded.
The appropriate native library must be manually moved from the resources/nativeAuth
directory to the lib directory.<p>

To enable this provider, set the following in the system properties:

<ul>
<li>{@code provider.auth.className = org.jivesoftware.openfire.auth.NativeAuthProvider}</li>
<li>{@code provider.user.className = org.jivesoftware.openfire.user.NativeUserProvider}</li>
</ul>

The properties to configure the provider are as follows:

<ul>
     <li>nativeAuth.domain -- <i> on Windows, the domain to use for authentication.
     If the value is not set, the machine's default domain will be used or standard OS
     auth will be used if the machine is not part of a domain. On Unix/Linux, this
     value specifies the PAM module to use for authentication. If the value is not set,
     the PAM module "other" will be used.</i></li>
</ul>

For more information about configuring the domain value and other aspects of Shaj,
please see: <a href="http://opensource.cenqua.com/shaj/doc.html">
http://opensource.cenqua.com/shaj/doc.html</a>.

@author Matt Tucker
xmppserver/src/main/java/org/jivesoftware/openfire/auth/NativeAuthProvider.java