1<?php
2
3namespace Sabre\VObject;
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) 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     *
25     * @return string
26     */
27    static function getUUID() {
28
29        return sprintf(
30
31            '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
32
33            // 32 bits for "time_low"
34            mt_rand(0, 0xffff), mt_rand(0, 0xffff),
35
36            // 16 bits for "time_mid"
37            mt_rand(0, 0xffff),
38
39            // 16 bits for "time_hi_and_version",
40            // four most significant bits holds version number 4
41            mt_rand(0, 0x0fff) | 0x4000,
42
43            // 16 bits, 8 bits for "clk_seq_hi_res",
44            // 8 bits for "clk_seq_low",
45            // two most significant bits holds zero and one for variant DCE1.1
46            mt_rand(0, 0x3fff) | 0x8000,
47
48            // 48 bits for "node"
49            mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
50        );
51    }
52
53    /**
54     * Checks if a string is a valid UUID.
55     *
56     * @param string $uuid
57     *
58     * @return bool
59     */
60    static function validateUUID($uuid) {
61
62        return preg_match(
63            '/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/i',
64            $uuid
65        ) !== 0;
66
67    }
68
69}
70