vendor/OTPHP/Base32.php

   1 <?php
   2
   3 namespace OTPHP;
   4
   5 /**
   6  * Encode in Base32 based on RFC 4648.
   7  * Requires 20% more space than base64
   8  * Great for case-insensitive filesystems like Windows and URL's  (except for = char which can be excluded using the pad option for urls)
   9  *
  10  * @package default
  11  * @author Bryan Ruiz
  12  **/
  13 class Base32 {
  14
  15    private static $map = array(
  16         'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', //  7
  17         'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15
  18         'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23
  19         'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31
  20         '='  // padding char
  21     );
  22
  23    private static $flippedMap = array(
  24         'A'=>'0', 'B'=>'1', 'C'=>'2', 'D'=>'3', 'E'=>'4', 'F'=>'5', 'G'=>'6', 'H'=>'7',
  25         'I'=>'8', 'J'=>'9', 'K'=>'10', 'L'=>'11', 'M'=>'12', 'N'=>'13', 'O'=>'14', 'P'=>'15',
  26         'Q'=>'16', 'R'=>'17', 'S'=>'18', 'T'=>'19', 'U'=>'20', 'V'=>'21', 'W'=>'22', 'X'=>'23',
  27         'Y'=>'24', 'Z'=>'25', '2'=>'26', '3'=>'27', '4'=>'28', '5'=>'29', '6'=>'30', '7'=>'31'
  28     );
  29
  30     /**
  31      *    Use padding false when encoding for urls
  32      *
  33      * @return base32 encoded string
  34      * @author Bryan Ruiz
  35      **/
  36     public static function encode($input, $padding = true) {
  37         if(empty($input)) return "";
  38         $input = str_split($input);
  39         $binaryString = "";
  40         for($i = 0; $i < count($input); $i++) {
  41             $binaryString .= str_pad(base_convert(ord($input[$i]), 10, 2), 8, '0', STR_PAD_LEFT);
  42         }
  43         $fiveBitBinaryArray = str_split($binaryString, 5);
  44         $base32 = "";
  45         $i=0;
  46         while($i < count($fiveBitBinaryArray)) {
  47             $base32 .= self::$map[base_convert(str_pad($fiveBitBinaryArray[$i], 5,'0'), 2, 10)];
  48             $i++;
  49         }
  50         if($padding && ($x = strlen($binaryString) % 40) != 0) {
  51             if($x == 8) $base32 .= str_repeat(self::$map[32], 6);
  52             else if($x == 16) $base32 .= str_repeat(self::$map[32], 4);
  53             else if($x == 24) $base32 .= str_repeat(self::$map[32], 3);
  54             else if($x == 32) $base32 .= self::$map[32];
  55         }
  56         return $base32;
  57     }
  58
  59     public static function decode($input) {
  60         if(empty($input)) return;
  61         $paddingCharCount = substr_count($input, self::$map[32]);
  62         $allowedValues = array(6,4,3,1,0);
  63         if(!in_array($paddingCharCount, $allowedValues)) return false;
  64         for($i=0; $i<4; $i++){
  65             if($paddingCharCount == $allowedValues[$i] &&
  66                 substr($input, -($allowedValues[$i])) != str_repeat(self::$map[32], $allowedValues[$i])) return false;
  67         }
  68         $input = str_replace('=','', $input);
  69         $input = str_split($input);
  70         $binaryString = "";
  71         for($i=0; $i < count($input); $i = $i+8) {
  72             $x = "";
  73             if(!in_array($input[$i], self::$map)) return false;
  74             for($j=0; $j < 8; $j++) {
  75                 $x .= str_pad(base_convert(@self::$flippedMap[@$input[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT);
  76             }
  77             $eightBits = str_split($x, 8);
  78             for($z = 0; $z < count($eightBits); $z++) {
  79                 $binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:"";
  80             }
  81         }
  82         return $binaryString;
  83     }
  84 }
  85