1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
<?php
/**
* Encode in Base32 based on RFC 4648.
* Requires 20% more space than base64
* Great for case-insensitive filesystems like Windows and URL's (except for = char which can be excluded using the pad option for urls)
*
* @package default
* @author Bryan Ruiz
**/
class Base32 {
private static $map = array(
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', // 7
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23
'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31
'=' // padding char
);
private static $flippedMap = array(
'A'=>'0', 'B'=>'1', 'C'=>'2', 'D'=>'3', 'E'=>'4', 'F'=>'5', 'G'=>'6', 'H'=>'7',
'I'=>'8', 'J'=>'9', 'K'=>'10', 'L'=>'11', 'M'=>'12', 'N'=>'13', 'O'=>'14', 'P'=>'15',
'Q'=>'16', 'R'=>'17', 'S'=>'18', 'T'=>'19', 'U'=>'20', 'V'=>'21', 'W'=>'22', 'X'=>'23',
'Y'=>'24', 'Z'=>'25', '2'=>'26', '3'=>'27', '4'=>'28', '5'=>'29', '6'=>'30', '7'=>'31'
);
/**
* Use padding false when encoding for urls
*
* @return base32 encoded string
* @author Bryan Ruiz
**/
public static function encode($input, $padding = true) {
if(empty($input)) return "";
$input = str_split($input);
$binaryString = "";
for($i = 0; $i < count($input); $i++) {
$binaryString .= str_pad(base_convert(ord($input[$i]), 10, 2), 8, '0', STR_PAD_LEFT);
}
$fiveBitBinaryArray = str_split($binaryString, 5);
$base32 = "";
$i=0;
while($i < count($fiveBitBinaryArray)) {
$base32 .= self::$map[base_convert(str_pad($fiveBitBinaryArray[$i], 5,'0'), 2, 10)];
$i++;
}
if($padding && ($x = strlen($binaryString) % 40) != 0) {
if($x == 8) $base32 .= str_repeat(self::$map[32], 6);
else if($x == 16) $base32 .= str_repeat(self::$map[32], 4);
else if($x == 24) $base32 .= str_repeat(self::$map[32], 3);
else if($x == 32) $base32 .= self::$map[32];
}
return $base32;
}
public static function decode($input) {
if(empty($input)) return;
$paddingCharCount = substr_count($input, self::$map[32]);
$allowedValues = array(6,4,3,1,0);
if(!in_array($paddingCharCount, $allowedValues)) return false;
for($i=0; $i<4; $i++){
if($paddingCharCount == $allowedValues[$i] &&
substr($input, -($allowedValues[$i])) != str_repeat(self::$map[32], $allowedValues[$i])) return false;
}
$input = str_replace('=','', $input);
$input = str_split($input);
$binaryString = "";
for($i=0; $i < count($input); $i = $i+8) {
$x = "";
if(!in_array($input[$i], self::$map)) return false;
for($j=0; $j < 8; $j++) {
$x .= str_pad(base_convert(@self::$flippedMap[@$input[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT);
}
$eightBits = str_split($x, 8);
for($z = 0; $z < count($eightBits); $z++) {
$binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:"";
}
}
return $binaryString;
}
}
|
GitWeb