1: <?php
 2: 
 3: /**
 4:  * This file is part of the Nette Framework (https://nette.org)
 5:  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 6:  */
 7: 
 8: namespace Nette\Utils;
 9: 
10: use Nette;
11: 
12: 
13: /**
14:  * Secure random string generator.
15:  */
16: class Random
17: {
18:     use Nette\StaticClass;
19: 
20:     /**
21:      * Generate random string.
22:      * @param  int
23:      * @param  string
24:      * @return string
25:      */
26:     public static function generate($length = 10, $charlist = '0-9a-z')
27:     {
28:         $charlist = count_chars(preg_replace_callback('#.-.#', function (array $m) {
29:             return implode('', range($m[0][0], $m[0][2]));
30:         }, $charlist), 3);
31:         $chLen = strlen($charlist);
32: 
33:         if ($length < 1) {
34:             throw new Nette\InvalidArgumentException('Length must be greater than zero.');
35:         } elseif ($chLen < 2) {
36:             throw new Nette\InvalidArgumentException('Character list must contain as least two chars.');
37:         }
38: 
39:         $res = '';
40:         if (PHP_VERSION_ID >= 70000) {
41:             for ($i = 0; $i < $length; $i++) {
42:                 $res .= $charlist[random_int(0, $chLen - 1)];
43:             }
44:             return $res;
45:         }
46: 
47:         $bytes = '';
48:         if (function_exists('openssl_random_pseudo_bytes')) {
49:             $bytes = (string) openssl_random_pseudo_bytes($length, $secure);
50:             if (!$secure) {
51:                 $bytes = '';
52:             }
53:         }
54:         if (strlen($bytes) < $length && function_exists('mcrypt_create_iv')) {
55:             $bytes = (string) mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
56:         }
57:         if (strlen($bytes) < $length && !defined('PHP_WINDOWS_VERSION_BUILD') && is_readable('/dev/urandom')) {
58:             $bytes = (string) file_get_contents('/dev/urandom', false, null, -1, $length);
59:         }
60:         if (strlen($bytes) < $length) {
61:             $rand3 = md5(serialize($_SERVER), true);
62:             $charlist = str_shuffle($charlist);
63:             for ($i = 0; $i < $length; $i++) {
64:                 if ($i % 5 === 0) {
65:                     list($rand1, $rand2) = explode(' ', microtime());
66:                     $rand1 += lcg_value();
67:                 }
68:                 $rand1 *= $chLen;
69:                 $res .= $charlist[($rand1 + $rand2 + ord($rand3[$i % strlen($rand3)])) % $chLen];
70:                 $rand1 -= (int) $rand1;
71:             }
72:             return $res;
73:         }
74: 
75:         for ($i = 0; $i < $length; $i++) {
76:             $res .= $charlist[($i + ord($bytes[$i])) % $chLen];
77:         }
78:         return $res;
79:     }
80: }
81: