Authed Component, 
 PHP versions 4 and 5
 
Custom scope rules for AuthComponent

The purpose of this extension is to add a flexible rule setup to
the login process. You could compare their setup to model validation.
The rules are applied just before the usual auth is issued.

Note: This extension overwrites Auth::login()

Example:

  $this->Authed->loginError = __("Wrong password / username. Please try again.", true);
  $this->Authed->authError = __("Sorry, you are not authorized. Please log in first.", true);

  $this->Authed->userScopeRules = array(
    'is_banned' => array(
      'expected' => 0,
      'message' => __("You are banned from this service. Sorry.", true)
    ),
    'is_validated' => array(
      'expected' => 1,
      'message' => __("Your account is not active yet. Click the Link in our Mail.", true)
    )
  );