|
1
|
|
|
<?php |
|
2
|
|
|
declare(strict_types=1); |
|
3
|
|
|
|
|
4
|
|
|
|
|
5
|
|
|
namespace Tfboe\FmLib\Helpers; |
|
6
|
|
|
|
|
7
|
|
|
|
|
8
|
|
|
use Tfboe\FmLib\Exceptions\Internal; |
|
9
|
|
|
|
|
10
|
|
|
/** |
|
11
|
|
|
* Class Random |
|
12
|
|
|
* @package Tfboe\FmLib\Helpers |
|
13
|
|
|
*/ |
|
14
|
|
|
class Random |
|
15
|
|
|
{ |
|
16
|
|
|
//<editor-fold desc="Fields"> |
|
17
|
|
|
private const ENTROPY = [ |
|
18
|
|
|
1 => 2, |
|
19
|
|
|
2 => 4, |
|
20
|
|
|
3 => 8 |
|
21
|
|
|
]; |
|
22
|
|
|
|
|
23
|
|
|
/** |
|
24
|
|
|
* @var string |
|
25
|
|
|
*/ |
|
26
|
|
|
private $hexString; |
|
27
|
|
|
|
|
28
|
|
|
/** |
|
29
|
|
|
* @var int |
|
30
|
|
|
*/ |
|
31
|
|
|
private $remainingBitsFirstChar; |
|
32
|
|
|
//</editor-fold desc="Fields"> |
|
33
|
|
|
|
|
34
|
|
|
//<editor-fold desc="Constructor"> |
|
35
|
|
|
/** |
|
36
|
|
|
* Random constructor. |
|
37
|
|
|
* @param string $hexString |
|
38
|
|
|
*/ |
|
39
|
|
|
public function __construct(string $hexString) |
|
40
|
|
|
{ |
|
41
|
|
|
$this->hexString = $hexString; |
|
42
|
|
|
$this->remainingBitsFirstChar = 4; |
|
43
|
|
|
} |
|
44
|
|
|
//</editor-fold desc="Constructor"> |
|
45
|
|
|
|
|
46
|
|
|
//<editor-fold desc="Public Methods"> |
|
47
|
|
|
/** |
|
48
|
|
|
* @param int $max |
|
49
|
|
|
* @param int $min |
|
50
|
|
|
* @return int |
|
51
|
|
|
*/ |
|
52
|
|
|
public function extractEntropy(int $max, int $min = 0): int |
|
53
|
|
|
{ |
|
54
|
|
|
Internal::assert($max <= PHP_INT_MAX && $min >= PHP_INT_MIN && $min <= $max); |
|
55
|
|
|
$maxInt = (PHP_INT_MAX >> 1); |
|
56
|
|
|
if (($max > $maxInt && ($min <= 0 || $max - $min > $maxInt)) || |
|
57
|
|
|
($min < -$maxInt && ($max >= 0 || $max - $min > $maxInt)) || ($max - $min) > $maxInt) { |
|
58
|
|
|
//calculate floor(($max - $min) / 16) considering overflows |
|
59
|
|
|
$max16 = $max % 16; |
|
60
|
|
|
$min16 = $min % 16; |
|
61
|
|
|
$max1 = (($max - $max16) >> 4) - (($min - $min16) >> 4); |
|
62
|
|
|
$rest = $max16 - $min16; |
|
63
|
|
|
if ($rest >= 16) { |
|
64
|
|
|
$max1++; |
|
65
|
|
|
$rest -= 16; |
|
66
|
|
|
} |
|
67
|
|
|
|
|
68
|
|
|
$z1 = $this->extractEntropy($max1); |
|
69
|
|
|
$max2 = 15; |
|
70
|
|
|
if ($z1 == $max1) { |
|
71
|
|
|
$max2 = $rest; |
|
72
|
|
|
} |
|
73
|
|
|
$z2 = $this->extractEntropy($max2); |
|
74
|
|
|
return (($min + 8 * $z1) + 8 * $z1) + $z2; |
|
75
|
|
|
} |
|
76
|
|
|
$range = $max - $min; |
|
77
|
|
|
Internal::assert($range <= PHP_INT_MAX); |
|
78
|
|
|
$bits = static::countBits($range); |
|
79
|
|
|
|
|
80
|
|
|
return $min + ($this->extractEntropyByBits($bits) % ($range + 1)); |
|
81
|
|
|
} |
|
82
|
|
|
|
|
83
|
|
|
/** |
|
84
|
|
|
* @param int $bits |
|
85
|
|
|
* @return int |
|
86
|
|
|
*/ |
|
87
|
|
|
public function extractEntropyByBits(int $bits): int |
|
88
|
|
|
{ |
|
89
|
|
|
Internal::assert($bits >= 0); |
|
90
|
|
|
if ($bits === 0 || empty($this->hexString)) { |
|
91
|
|
|
return 0; //no entropy |
|
92
|
|
|
} |
|
93
|
|
|
$value = 0; |
|
94
|
|
|
if ($bits >= $this->remainingBitsFirstChar) { |
|
95
|
|
|
//extract full positions |
|
96
|
|
|
$fullExtractLength = 1 + (($bits - $this->remainingBitsFirstChar) >> 2); |
|
97
|
|
|
$value = hexdec(substr($this->hexString, 0, $fullExtractLength)); |
|
98
|
|
|
$bits -= $this->remainingBitsFirstChar + ($fullExtractLength - 1) * 4; |
|
99
|
|
|
$this->remainingBitsFirstChar = 4; |
|
100
|
|
|
$this->hexString = substr($this->hexString, $fullExtractLength); |
|
101
|
|
|
if (empty($this->hexString)) { |
|
102
|
|
|
return $value; |
|
|
|
|
|
|
103
|
|
|
} |
|
104
|
|
|
} |
|
105
|
|
|
if ($bits > 0) { |
|
106
|
|
|
$digit = hexdec(substr($this->hexString, 0, 1)); |
|
107
|
|
|
$r = self::ENTROPY[$bits]; |
|
108
|
|
|
$value *= $r; |
|
109
|
|
|
$this->remainingBitsFirstChar -= $bits; |
|
110
|
|
|
$value += $digit >> $this->remainingBitsFirstChar; |
|
111
|
|
|
$this->hexString = dechex($digit & (self::ENTROPY[$this->remainingBitsFirstChar] - 1)) |
|
112
|
|
|
. substr($this->hexString, 1); |
|
113
|
|
|
} |
|
114
|
|
|
return $value; |
|
|
|
|
|
|
115
|
|
|
} |
|
116
|
|
|
|
|
117
|
|
|
/** |
|
118
|
|
|
* @param $str |
|
119
|
|
|
* @return Random |
|
120
|
|
|
*/ |
|
121
|
|
|
public static function stringToRandom($str): Random |
|
122
|
|
|
{ |
|
123
|
|
|
return new Random(hash("sha256", $str)); |
|
124
|
|
|
} |
|
125
|
|
|
//</editor-fold desc="Public Methods"> |
|
126
|
|
|
|
|
127
|
|
|
//<editor-fold desc="Private Methods"> |
|
128
|
|
|
/** |
|
129
|
|
|
* @param $n |
|
130
|
|
|
* @return int |
|
131
|
|
|
*/ |
|
132
|
|
|
private static function countBits(int $n): int |
|
133
|
|
|
{ |
|
134
|
|
|
$count = 0; |
|
135
|
|
|
while ($n > 0) { |
|
136
|
|
|
$count++; |
|
137
|
|
|
$n >>= 1; |
|
138
|
|
|
} |
|
139
|
|
|
return $count; |
|
140
|
|
|
} |
|
141
|
|
|
//</editor-fold desc="Private Methods"> |
|
142
|
|
|
} |
tfboe /
fm-lib
Loading history...