CakePHP4でクッキーを使用して、自動ログインを実装する

use Cake\Http\Cookie\Cookie;
use DateTime;

public function login()
{
    $result = $this->Authentication->getResult();
    if ($result->isValid()) {
        if ($this->request->is('post') && $this->request->getData('autologin') === '1') {
            // ログイン情報をDBとクッキーに保存する
            $user = $result->getData();
            $db_user = $this->Users->get($user['id']);
            $set_key = hash('sha256', (uniqid() . mt_rand(1, 999999999) . '_auto_logins'));
            $db_user->login_key = $set_key;
            $this->Users->save($db_user);

            $this->response = $this->response->withCookie(Cookie::create(
                User::KEY_AUTO_LOGIN,
                $set_key,
                [
                    'expires' => new DateTime('+1 month'),
                ]
            ));
        }

        // ログイン済みの場合はリダイレクト
        $target = $this->Authentication->getLoginRedirect() ?? '/mypage';
        return $this->redirect($target);
    }
    ....
}

public function login()
{
    ......
    if ($this->request->is('get')) {
        // クッキーにログインキーが保存されていて、DBと一致する場合、自動ログインする
        $autoLoginKey = $this->request->getCookie(User::KEY_AUTO_LOGIN);
        if ($autoLoginKey != null) {
            $user = $this->Users->find()->where(['login_key' => $autoLoginKey])->first();
            if ($user != null) {
                $this->Authentication->setIdentity($user);
                return $this->redirect(['controller' => 'Mypage']);
            }
        }
    }
}

public function logout()
{
    $result = $this->Authentication->getResult();
    if ($result->isValid()) {
        $user = $this->request->getAttribute('authentication')->getIdentity();
        $db_user = $this->Users->get($user['id']);
        if ($db_user->login_key != null) {
            $db_user->login_key = null;
            $this->Users->save($db_user);

            $this->response = $this->response->withExpiredCookie(new Cookie(User::KEY_AUTO_LOGIN));
        }

        $this->Authentication->logout();
    }
    $this->Flash->success('ログアウトしました。');
    return $this->redirect(['controller' => 'Users', 'action' => 'login']);
}