83 lines
2.3 KiB
PHP
83 lines
2.3 KiB
PHP
|
<?php
|
||
|
|
|
||
|
|
declare(strict_types=1);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @copyright Copyright (c) 2016, ownCloud, Inc.
|
||
|
|
*
|
||
|
|
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
|
||
|
|
* @author Leon Klingele <git@leonklingele.de>
|
||
|
|
* @author Lukas Reschke <lukas@statuscode.ch>
|
||
|
|
* @author Roeland Jago Douma <roeland@famdouma.nl>
|
||
|
|
*
|
||
|
|
* @license AGPL-3.0
|
||
|
|
*
|
||
|
|
* This code is free software: you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU Affero General Public License, version 3,
|
||
|
|
* as published by the Free Software Foundation.
|
||
|
|
*
|
||
|
|
* 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 Affero General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU Affero General Public License, version 3,
|
||
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
namespace OC\Security\CSRF;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Class CsrfToken represents the stored or provided CSRF token. To mitigate
|
||
|
|
* BREACH alike vulnerabilities the token is returned in an encrypted value as
|
||
|
|
* well in an unencrypted value. For display measures to the user always the
|
||
|
|
* unencrypted one should be chosen.
|
||
|
|
*
|
||
|
|
* @package OC\Security\CSRF
|
||
|
|
*/
|
||
|
|
class CsrfToken {
|
||
|
|
/** @var string */
|
||
|
|
private $value;
|
||
|
|
/** @var string */
|
||
|
|
private $encryptedValue = '';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @param string $value Value of the token. Can be encrypted or not encrypted.
|
||
|
|
*/
|
||
|
|
public function __construct(string $value) {
|
||
|
|
$this->value = $value;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Encrypted value of the token. This is used to mitigate BREACH alike
|
||
|
|
* vulnerabilities. For display measures do use this functionality.
|
||
|
|
*
|
||
|
|
* @return string
|
||
|
|
*/
|
||
|
|
public function getEncryptedValue(): string {
|
||
|
|
if ($this->encryptedValue === '') {
|
||
|
|
$sharedSecret = random_bytes(\strlen($this->value));
|
||
|
|
$this->encryptedValue = base64_encode($this->value ^ $sharedSecret) . ':' . base64_encode($sharedSecret);
|
||
|
|
}
|
||
|
|
|
||
|
|
return $this->encryptedValue;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The unencrypted value of the token. Used for decrypting an already
|
||
|
|
* encrypted token.
|
||
|
|
*
|
||
|
|
* @return string
|
||
|
|
*/
|
||
|
|
public function getDecryptedValue(): string {
|
||
|
|
$token = explode(':', $this->value);
|
||
|
|
if (\count($token) !== 2) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
$obfuscatedToken = $token[0];
|
||
|
|
$secret = $token[1];
|
||
|
|
return base64_decode($obfuscatedToken) ^ base64_decode($secret);
|
||
|
|
}
|
||
|
|
}
|