server/lib/private/Security/SecureRandom.php
2016-05-26 19:57:24 +02:00

86 lines
2.8 KiB
PHP

<?php
/**
* @author Lukas Reschke <lukas@statuscode.ch>
* @author Morris Jobke <hey@morrisjobke.de>
*
* @copyright Copyright (c) 2016, ownCloud, Inc.
* @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;
use RandomLib;
use Sabre\DAV\Exception;
use OCP\Security\ISecureRandom;
/**
* Class SecureRandom provides a wrapper around the random_int function to generate
* secure random strings. For PHP 7 the native CSPRNG is used, older versions do
* use a fallback.
*
* Usage:
* \OC::$server->getSecureRandom()->generate(10);
* @package OC\Security
*/
class SecureRandom implements ISecureRandom {
/**
* Convenience method to get a low strength random number generator.
*
* Low Strength should be used anywhere that random strings are needed
* in a non-cryptographical setting. They are not strong enough to be
* used as keys or salts. They are however useful for one-time use tokens.
*
* @deprecated 9.0.0 Use \OC\Security\SecureRandom::generate directly or random_bytes() / random_int()
* @return $this
*/
public function getLowStrengthGenerator() {
return $this;
}
/**
* Convenience method to get a medium strength random number generator.
*
* Medium Strength should be used for most needs of a cryptographic nature.
* They are strong enough to be used as keys and salts. However, they do
* take some time and resources to generate, so they should not be over-used
*
* @deprecated 9.0.0 Use \OC\Security\SecureRandom::generate directly or random_bytes() / random_int()
* @return $this
*/
public function getMediumStrengthGenerator() {
return $this;
}
/**
* Generate a random string of specified length.
* @param int $length The length of the generated string
* @param string $characters An optional list of characters to use if no character list is
* specified all valid base64 characters are used.
* @return string
*/
public function generate($length,
$characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/') {
$maxCharIndex = strlen($characters) - 1;
$randomString = '';
while($length > 0) {
$randomNumber = \random_int(0, $maxCharIndex);
$randomString .= $characters[$randomNumber];
$length--;
}
return $randomString;
}
}