lithium\security\auth\adapter\Http::_basic PHP Method

    protected function _basic($request)
    {
        $users = $this->_config['users'];
        $username = $request->env('PHP_AUTH_USER');
        $auth = $this->_classes['auth'];
        $basic = $auth::encode($username, $request->env('PHP_AUTH_PW'));
        $encoded = array('response' => null);
        if (isset($users[$username])) {
            $encoded = $auth::encode($username, $users[$username]);
        }
        if ($basic['response'] !== $encoded['response']) {
            $this->_writeHeader("WWW-Authenticate: Basic realm=\"{$this->_config['realm']}\"");
            return;
        }
        return compact('username', 'password');
    }