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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; }} |
