|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
declare(strict_types=1); |
|
4
|
|
|
|
|
5
|
|
|
/** |
|
6
|
|
|
* Str.php. |
|
7
|
|
|
* |
|
8
|
|
|
* PHP version 7 |
|
9
|
|
|
* |
|
10
|
|
|
* @category Dcrypt |
|
11
|
|
|
* |
|
12
|
|
|
* @author Michael Meyer (mmeyer2k) <[email protected]> |
|
13
|
|
|
* @license http://opensource.org/licenses/MIT The MIT License (MIT) |
|
14
|
|
|
* |
|
15
|
|
|
* @link https://github.com/mmeyer2k/dcrypt |
|
16
|
|
|
*/ |
|
17
|
|
|
|
|
18
|
|
|
namespace Dcrypt; |
|
19
|
|
|
|
|
20
|
|
|
/** |
|
21
|
|
|
* Provides time-safe string comparison facilities, and safe string operations |
|
22
|
|
|
* on systems that have mb_* function overloading enabled. |
|
23
|
|
|
* |
|
24
|
|
|
* The functions in this class were inspired by the symfony's StringUtils class. |
|
25
|
|
|
* |
|
26
|
|
|
* @category Dcrypt |
|
27
|
|
|
* |
|
28
|
|
|
* @author Michael Meyer (mmeyer2k) <[email protected]> |
|
29
|
|
|
* @license http://opensource.org/licenses/MIT The MIT License (MIT) |
|
30
|
|
|
* |
|
31
|
|
|
* @link https://github.com/mmeyer2k/dcrypt |
|
32
|
|
|
* @link https://github.com/symfony/Security/blob/master/Core/Util/StringUtils.php |
|
33
|
|
|
* @link https://php.net/manual/en/mbstring.overload.php |
|
34
|
|
|
*/ |
|
35
|
|
|
final class Str |
|
36
|
|
|
{ |
|
37
|
|
|
/** |
|
38
|
|
|
* Compares two strings in constant time. Strings are hashed before |
|
39
|
|
|
* comparison so information is not leaked when strings are not of |
|
40
|
|
|
* equal length. |
|
41
|
|
|
* |
|
42
|
|
|
* @param string $known The string of known length to compare against |
|
43
|
|
|
* @param string $given The string that the user can control |
|
44
|
|
|
* |
|
45
|
|
|
* @return bool |
|
46
|
|
|
*/ |
|
47
|
34 |
|
public static function equal(string $known, string $given): bool |
|
48
|
|
|
{ |
|
49
|
|
|
// Create some entropy |
|
50
|
34 |
|
$nonce = \random_bytes(16); |
|
51
|
|
|
|
|
52
|
|
|
// Prehash the input strings with the nonce |
|
53
|
34 |
|
$known = \hash_hmac('sha256', $known, $nonce, true); |
|
54
|
34 |
|
$given = \hash_hmac('sha256', $given, $nonce, true); |
|
55
|
|
|
|
|
56
|
34 |
|
return \hash_equals($known, $given); |
|
57
|
|
|
} |
|
58
|
|
|
|
|
59
|
|
|
/** |
|
60
|
|
|
* Determine the length of the output of a given hash algorithm in bytes. |
|
61
|
|
|
* |
|
62
|
|
|
* @param string $algo Name of algorithm to look up |
|
63
|
|
|
* |
|
64
|
|
|
* @return int |
|
65
|
|
|
*/ |
|
66
|
35 |
|
public static function hashSize(string $algo): int |
|
67
|
|
|
{ |
|
68
|
35 |
|
return self::strlen(\hash($algo, 'hash me', true)); |
|
69
|
|
|
} |
|
70
|
|
|
|
|
71
|
|
|
/** |
|
72
|
|
|
* Returns the number of bytes in a string. |
|
73
|
|
|
* |
|
74
|
|
|
* @param string $string The string whose length we wish to obtain |
|
75
|
|
|
* |
|
76
|
|
|
* @return int |
|
77
|
|
|
*/ |
|
78
|
44 |
|
public static function strlen(string $string): int |
|
79
|
|
|
{ |
|
80
|
44 |
|
return \mb_strlen($string, '8bit'); |
|
81
|
|
|
} |
|
82
|
|
|
|
|
83
|
|
|
/** |
|
84
|
|
|
* Returns part of a string. |
|
85
|
|
|
* |
|
86
|
|
|
* @param string $string The string whose length we wish to obtain |
|
87
|
|
|
* @param int $start Offset to start gathering output |
|
88
|
|
|
* @param int $length Distance from starting offset to gather |
|
89
|
|
|
* |
|
90
|
|
|
* @return string |
|
91
|
|
|
*/ |
|
92
|
33 |
|
public static function substr( |
|
93
|
|
|
string $string, |
|
94
|
|
|
int $start, |
|
95
|
|
|
int $length = null |
|
96
|
|
|
): string { |
|
97
|
33 |
|
return \mb_substr($string, $start, $length, '8bit'); |
|
98
|
|
|
} |
|
99
|
|
|
} |
|
100
|
|
|
|
mmeyer2k /
dcrypt
