<?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;␍␊ |
}␍␊ |
}␍␊ |