Zabbix

<?php declare(strict_types = 1);

/*

** Zabbix

** Copyright (C) 2001-2022 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

​

/**

 * Helper class for sign / encrypt data.

 */

class CEncryptHelper {

​

    /**

     * Signature algorithm.

     */

    public const SIGN_ALGO = 'sha256';

​

    /**

     * Session secret key.

     *

     * @var string

     */

    private static $key;

​

    /**

     * Return session key.

     *

     * @return string|null

     */

    private static function getKey(): ?string {

        if (!self::$key) {

            // This if contain copy in CEncryptedCookieSession class.

            if (CSettingsHelper::getGlobal(CSettingsHelper::SESSION_KEY) === '') {

                self::$key = self::generateKey();

​

                if (!self::updateKey(self::$key)) {

                    return null;

                }

​

                return self::$key;

            }

​

            self::$key = CSettingsHelper::getGlobal(CSettingsHelper::SESSION_KEY);

        }

​

        return self::$key;

    }

​

    /**