9.5/_form_session_8php_source.html

<?php

declare(strict_types = 1);

namespace ‪TYPO3\CMS\Form\Domain\Runtime\FormRuntime;


/*

 * This file is part of the TYPO3 CMS project.

 *

 * It is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, either version 2

 * of the License, or any later version.

 *

 * For the full copyright and license information, please read the

 * LICENSE.txt file that was distributed with this source code.

 *

 * The TYPO3 project - inspiring people to share!

 */


use ‪TYPO3\CMS\Core\Crypto\Random;

use ‪TYPO3\CMS\Core\Error\Http\BadRequestException;

use ‪TYPO3\CMS\Core\Utility\GeneralUtility;

use ‪TYPO3\CMS\Extbase\Security\Cryptography\HashService;

use ‪TYPO3\CMS\Extbase\Security\Exception\InvalidArgumentForHashGenerationException;

use ‪TYPO3\CMS\Extbase\Security\Exception\InvalidHashException;


class ‪FormSession

{

    protected ‪$identifier;


    public function ‪__construct(string $authenticatedIdentifier = null)

    {

        if ($authenticatedIdentifier === null) {

            $this->identifier = $this->‪generateIdentifier();

        } else {

            $this->identifier = $this->‪validateIdentifier($authenticatedIdentifier);

        }

    }


    public function ‪getIdentifier(): string

    {

        return ‪$this->identifier;

    }


    public function ‪getAuthenticatedIdentifier(): string

    {

        return GeneralUtility::makeInstance(HashService::class)

            // restrict string expansion by adding some char ('|')

            ->appendHmac($this->identifier . '|');

    }


    protected function ‪generateIdentifier(): string

    {

        return GeneralUtility::makeInstance(Random::class)->generateRandomHexString(40);

    }


    protected function ‪validateIdentifier(string $authenticatedIdentifier): string

    {

        try {

            ‪$identifier = GeneralUtility::makeInstance(HashService::class)

                ->validateAndStripHmac($authenticatedIdentifier);

            return rtrim(‪$identifier, '|');

        } catch (‪InvalidHashException | ‪InvalidArgumentForHashGenerationException $e) {

            throw new ‪BadRequestException('The HMAC of the form session could not be validated.', 1613300274);

        }

    }

}