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