1<?php
2
3namespace Sabre\DAV;
4
5/**
6 * UUID Utility
7 *
8 * This class has static methods to generate and validate UUID's.
9 * UUIDs are used a decent amount within various *DAV standards, so it made
10 * sense to include it.
11 *
12 * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
13 * @author Evert Pot (http://evertpot.com/)
14 * @license http://sabre.io/license/ Modified BSD License
15 */
16class UUIDUtil {
17
18    /**
19     * Returns a pseudo-random v4 UUID
20     *
21     * This function is based on a comment by Andrew Moore on php.net
22     *
23     * @see http://www.php.net/manual/en/function.uniqid.php#94959
24     * @return string
25     */
26    static function getUUID() {
27
28        return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
29            // 32 bits for "time_low"
30            mt_rand(0, 0xffff), mt_rand(0, 0xffff),
31
32            // 16 bits for "time_mid"
33            mt_rand(0, 0xffff),
34
35            // 16 bits for "time_hi_and_version",
36            // four most significant bits holds version number 4
37            mt_rand(0, 0x0fff) | 0x4000,
38
39            // 16 bits, 8 bits for "clk_seq_hi_res",
40            // 8 bits for "clk_seq_low",
41            // two most significant bits holds zero and one for variant DCE1.1
42            mt_rand(0, 0x3fff) | 0x8000,
43
44            // 48 bits for "node"
45            mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
46        );
47    }
48
49    /**
50     * Checks if a string is a valid UUID.
51     *
52     * @param string $uuid
53     * @return bool
54     */
55    static function validateUUID($uuid) {
56
57        return preg_match(
58            '/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/i',
59            $uuid
60        ) !== 0;
61
62    }
63
64}
65