Subversion Repositories oidplus

Rev

Rev 827 | Blame | Compare with Previous | Last modification | View Log | RSS feed

  1. <?php
  2. declare(strict_types=1);
  3. namespace ParagonIE\ConstantTime;
  4.  
  5. /**
  6.  *  Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
  7.  *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
  8.  *
  9.  *  Permission is hereby granted, free of charge, to any person obtaining a copy
  10.  *  of this software and associated documentation files (the "Software"), to deal
  11.  *  in the Software without restriction, including without limitation the rights
  12.  *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13.  *  copies of the Software, and to permit persons to whom the Software is
  14.  *  furnished to do so, subject to the following conditions:
  15.  *
  16.  *  The above copyright notice and this permission notice shall be included in all
  17.  *  copies or substantial portions of the Software.
  18.  *
  19.  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20.  *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21.  *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22.  *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23.  *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24.  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  25.  *  SOFTWARE.
  26.  */
  27.  
  28. /**
  29.  * Class Base32Hex
  30.  * [0-9][A-V]
  31.  *
  32.  * @package ParagonIE\ConstantTime
  33.  */
  34. abstract class Base32Hex extends Base32
  35. {
  36.     /**
  37.      * Uses bitwise operators instead of table-lookups to turn 5-bit integers
  38.      * into 8-bit integers.
  39.      *
  40.      * @param int $src
  41.      * @return int
  42.      */
  43.     protected static function decode5Bits(int $src): int
  44.     {
  45.         $ret = -1;
  46.  
  47.         // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
  48.         $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
  49.  
  50.         // if ($src > 0x60 && $src < 0x77) ret += $src - 0x61 + 10 + 1; // -86
  51.         $ret += (((0x60 - $src) & ($src - 0x77)) >> 8) & ($src - 86);
  52.  
  53.         return $ret;
  54.     }
  55.  
  56.     /**
  57.      * Uses bitwise operators instead of table-lookups to turn 5-bit integers
  58.      * into 8-bit integers.
  59.      *
  60.      * @param int $src
  61.      * @return int
  62.      */
  63.     protected static function decode5BitsUpper(int $src): int
  64.     {
  65.         $ret = -1;
  66.  
  67.         // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
  68.         $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
  69.  
  70.         // if ($src > 0x40 && $src < 0x57) ret += $src - 0x41 + 10 + 1; // -54
  71.         $ret += (((0x40 - $src) & ($src - 0x57)) >> 8) & ($src - 54);
  72.  
  73.         return $ret;
  74.     }
  75.  
  76.     /**
  77.      * Uses bitwise operators instead of table-lookups to turn 8-bit integers
  78.      * into 5-bit integers.
  79.      *
  80.      * @param int $src
  81.      * @return string
  82.      */
  83.     protected static function encode5Bits(int $src): string
  84.     {
  85.         $src += 0x30;
  86.  
  87.         // if ($src > 0x39) $src += 0x61 - 0x3a; // 39
  88.         $src += ((0x39 - $src) >> 8) & 39;
  89.  
  90.         return \pack('C', $src);
  91.     }
  92.  
  93.     /**
  94.      * Uses bitwise operators instead of table-lookups to turn 8-bit integers
  95.      * into 5-bit integers.
  96.      *
  97.      * Uppercase variant.
  98.      *
  99.      * @param int $src
  100.      * @return string
  101.      */
  102.     protected static function encode5BitsUpper(int $src): string
  103.     {
  104.         $src += 0x30;
  105.  
  106.         // if ($src > 0x39) $src += 0x41 - 0x3a; // 7
  107.         $src += ((0x39 - $src) >> 8) & 7;
  108.  
  109.         return \pack('C', $src);
  110.     }
  111. }