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   1  <?php
   2  /**
   3   * Random_* Compatibility Library
   4   * for using the new PHP 7 random_* API in PHP 5 projects
   5   *
   6   * The MIT License (MIT)
   7   *
   8   * Copyright (c) 2015 - 2018 Paragon Initiative Enterprises
   9   *
  10   * Permission is hereby granted, free of charge, to any person obtaining a copy
  11   * of this software and associated documentation files (the "Software"), to deal
  12   * in the Software without restriction, including without limitation the rights
  13   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14   * copies of the Software, and to permit persons to whom the Software is
  15   * furnished to do so, subject to the following conditions:
  16   *
  17   * The above copyright notice and this permission notice shall be included in
  18   * all copies or substantial portions of the Software.
  19   *
  20   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26   * SOFTWARE.
  27   */
  28  
  29  if (!is_callable('RandomCompat_strlen')) {
  30      if (
  31          defined('MB_OVERLOAD_STRING')
  32              &&
  33          ((int) ini_get('mbstring.func_overload')) & MB_OVERLOAD_STRING
  34      ) {
  35          /**
  36           * strlen() implementation that isn't brittle to mbstring.func_overload
  37           *
  38           * This version uses mb_strlen() in '8bit' mode to treat strings as raw
  39           * binary rather than UTF-8, ISO-8859-1, etc
  40           *
  41           * @param string $binary_string
  42           *
  43           * @throws TypeError
  44           *
  45           * @return int
  46           */
  47          function RandomCompat_strlen($binary_string)
  48          {
  49              if (!is_string($binary_string)) {
  50                  throw new TypeError(
  51                      'RandomCompat_strlen() expects a string'
  52                  );
  53              }
  54  
  55              return (int) mb_strlen($binary_string, '8bit');
  56          }
  57  
  58      } else {
  59          /**
  60           * strlen() implementation that isn't brittle to mbstring.func_overload
  61           *
  62           * This version just used the default strlen()
  63           *
  64           * @param string $binary_string
  65           *
  66           * @throws TypeError
  67           *
  68           * @return int
  69           */
  70          function RandomCompat_strlen($binary_string)
  71          {
  72              if (!is_string($binary_string)) {
  73                  throw new TypeError(
  74                      'RandomCompat_strlen() expects a string'
  75                  );
  76              }
  77              return (int) strlen($binary_string);
  78          }
  79      }
  80  }
  81  
  82  if (!is_callable('RandomCompat_substr')) {
  83  
  84      if (
  85          defined('MB_OVERLOAD_STRING')
  86              &&
  87          ((int) ini_get('mbstring.func_overload')) & MB_OVERLOAD_STRING
  88      ) {
  89          /**
  90           * substr() implementation that isn't brittle to mbstring.func_overload
  91           *
  92           * This version uses mb_substr() in '8bit' mode to treat strings as raw
  93           * binary rather than UTF-8, ISO-8859-1, etc
  94           *
  95           * @param string $binary_string
  96           * @param int $start
  97           * @param int|null $length (optional)
  98           *
  99           * @throws TypeError
 100           *
 101           * @return string
 102           */
 103          function RandomCompat_substr($binary_string, $start, $length = null)
 104          {
 105              if (!is_string($binary_string)) {
 106                  throw new TypeError(
 107                      'RandomCompat_substr(): First argument should be a string'
 108                  );
 109              }
 110  
 111              if (!is_int($start)) {
 112                  throw new TypeError(
 113                      'RandomCompat_substr(): Second argument should be an integer'
 114                  );
 115              }
 116  
 117              if ($length === null) {
 118                  /**
 119                   * mb_substr($str, 0, NULL, '8bit') returns an empty string on
 120                   * PHP 5.3, so we have to find the length ourselves.
 121                   */
 122                  /** @var int $length */
 123                  $length = RandomCompat_strlen($binary_string) - $start;
 124              } elseif (!is_int($length)) {
 125                  throw new TypeError(
 126                      'RandomCompat_substr(): Third argument should be an integer, or omitted'
 127                  );
 128              }
 129  
 130              // Consistency with PHP's behavior
 131              if ($start === RandomCompat_strlen($binary_string) && $length === 0) {
 132                  return '';
 133              }
 134              if ($start > RandomCompat_strlen($binary_string)) {
 135                  return '';
 136              }
 137  
 138              return (string) mb_substr(
 139                  (string) $binary_string,
 140                  (int) $start,
 141                  (int) $length,
 142                  '8bit'
 143              );
 144          }
 145  
 146      } else {
 147  
 148          /**
 149           * substr() implementation that isn't brittle to mbstring.func_overload
 150           *
 151           * This version just uses the default substr()
 152           *
 153           * @param string $binary_string
 154           * @param int $start
 155           * @param int|null $length (optional)
 156           *
 157           * @throws TypeError
 158           *
 159           * @return string
 160           */
 161          function RandomCompat_substr($binary_string, $start, $length = null)
 162          {
 163              if (!is_string($binary_string)) {
 164                  throw new TypeError(
 165                      'RandomCompat_substr(): First argument should be a string'
 166                  );
 167              }
 168  
 169              if (!is_int($start)) {
 170                  throw new TypeError(
 171                      'RandomCompat_substr(): Second argument should be an integer'
 172                  );
 173              }
 174  
 175              if ($length !== null) {
 176                  if (!is_int($length)) {
 177                      throw new TypeError(
 178                          'RandomCompat_substr(): Third argument should be an integer, or omitted'
 179                      );
 180                  }
 181  
 182                  return (string) substr(
 183                      (string )$binary_string,
 184                      (int) $start,
 185                      (int) $length
 186                  );
 187              }
 188  
 189              return (string) substr(
 190                  (string) $binary_string,
 191                  (int) $start
 192              );
 193          }
 194      }
 195  }