owncloud/core

<?php
/**
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @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 OCP\Security;

/**
 * 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::$server->getSecureRandom()->generate(10);
 *
 * @package OCP\Security
 * @since 8.0.0
 */
interface ISecureRandom {
    /**
     * Flags for characters that can be used for <code>generate($length, $characters)</code>
     */
    public const CHAR_UPPER = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    public const CHAR_LOWER = 'abcdefghijklmnopqrstuvwxyz';
    public const CHAR_DIGITS = '0123456789';
    public const CHAR_SYMBOLS = '!\"#$%&\\\'()* +,-./:;<=>?@[\]^_`{|}~';

    /**
     * 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.
     *
     * @return $this
     * @since 8.0.0
     * @deprecated 9.0.0 Use \OC\Security\SecureRandom::generate directly or random_bytes() / random_int()
     */
    public function getLowStrengthGenerator();

    /**
     * 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
     *
     * @return $this
     * @since 8.0.0
     * @deprecated 9.0.0 Use \OC\Security\SecureRandom::generate directly or random_bytes() / random_int()
     */
    public function getMediumStrengthGenerator();

    /**
     * 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
     * @since 8.0.0
     */
    public function generate(
        $length,
        $characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
    );
}