The custom login XML configuration will guide the spider to correctly login to a site and maintain state information.
Here is an example that show how to make the xml configuration (this was used to login to macromedia site).

<CUSTOMLOGINCONFIG>
	<CODE class="faust.sacha.web.bot.spider.customlogin.CustomFormLoginCookie" />
	<LOCATION url="/bin/MM/hub/hubLogin.jsp?BV_SessionID=@@@@0731678618.1038986166@@@@amp;BV_EngineID=hadcfkkmkkkkbedcgemcgcfk.0" />
	<HANDLERCONFIG>
		<POSTDATA>
			login_action=submit&amp;from=login.jsp&amp;login.url_success=&amp;login.url_cancel=&amp;destination=/hub/home.jsp&amp;origin=&amp;login.member_id=user@domain.com&amp;login.password=123ABC&amp;Submit=Login
		</POSTDATA>
		<COOKIE>
			WCBCOOKIE
		</COOKIE>
	</HANDLERCONFIG>
</CUSTOMLOGINCONFIG>

Tag doc:

CODE:
The tag as 1 attribute called class. This indicates which class should handle the custom authentication. You can write your own custom login handler
as long as it extends the faust.sacha.web.bot.spider.customlogin.CustomLogin class.

LOCATION:
The tag as 1 attribute called url. This indicates where to send the authentication data.

HANDLECONFIG:
You can add what ever tag and data you wish in there. This data will be pass to the custom login handler to be parsed.
Refer to the login handler documentation.