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   1  <?php
   2  /*
   3   * This file is part of the PHPASN1 library.
   4   *
   5   * For the full copyright and license information, please view the LICENSE
   6   * file that was distributed with this source code.
   7   */
   8  
   9  namespace FG\Utility;
  10  
  11  /**
  12   * Class BigIntegerGmp
  13   * Integer representation of big numbers using the GMP extension to perform operations.
  14   * @package FG\Utility
  15   * @internal
  16   */
  17  class BigIntegerGmp extends BigInteger
  18  {
  19      /**
  20       * Resource handle.
  21       * @var \GMP
  22       */
  23      protected $_rh;
  24  
  25      public function __clone()
  26      {
  27          $this->_rh = gmp_add($this->_rh, 0);
  28      }
  29  
  30      protected function _fromString($str)
  31      {
  32          $this->_rh = gmp_init($str, 10);
  33      }
  34  
  35      protected function _fromInteger($integer)
  36      {
  37          $this->_rh = gmp_init($integer, 10);
  38      }
  39  
  40      public function __toString()
  41      {
  42          return gmp_strval($this->_rh, 10);
  43      }
  44  
  45      public function toInteger()
  46      {
  47          if ($this->compare(PHP_INT_MAX) > 0 || $this->compare(PHP_INT_MIN) < 0) {
  48              throw new \OverflowException(sprintf('Can not represent %s as integer.', $this));
  49          }
  50          return gmp_intval($this->_rh);
  51      }
  52  
  53      public function isNegative()
  54      {
  55          return gmp_sign($this->_rh) === -1;
  56      }
  57  
  58      protected function _unwrap($number)
  59      {
  60          if ($number instanceof self) {
  61              return $number->_rh;
  62          }
  63          return $number;
  64      }
  65  
  66      public function compare($number)
  67      {
  68          return gmp_cmp($this->_rh, $this->_unwrap($number));
  69      }
  70  
  71      public function add($b)
  72      {
  73          $ret = new self();
  74          $ret->_rh = gmp_add($this->_rh, $this->_unwrap($b));
  75          return $ret;
  76      }
  77  
  78      public function subtract($b)
  79      {
  80          $ret = new self();
  81          $ret->_rh = gmp_sub($this->_rh, $this->_unwrap($b));
  82          return $ret;
  83      }
  84  
  85      public function multiply($b)
  86      {
  87          $ret = new self();
  88          $ret->_rh = gmp_mul($this->_rh, $this->_unwrap($b));
  89          return $ret;
  90      }
  91  
  92      public function modulus($b)
  93      {
  94          $ret = new self();
  95          $ret->_rh = gmp_mod($this->_rh, $this->_unwrap($b));
  96          return $ret;
  97      }
  98  
  99      public function toPower($b)
 100      {
 101          if ($b instanceof self) {
 102              // gmp_pow accepts just an integer
 103              if ($b->compare(PHP_INT_MAX) > 0) {
 104                  throw new \UnexpectedValueException('Unable to raise to power greater than PHP_INT_MAX.');
 105              }
 106              $b = gmp_intval($b->_rh);
 107          }
 108          $ret = new self();
 109          $ret->_rh = gmp_pow($this->_rh, $b);
 110          return $ret;
 111      }
 112  
 113      public function shiftRight($bits=8)
 114      {
 115          $ret = new self();
 116          $ret->_rh = gmp_div($this->_rh, gmp_pow(2, $bits));
 117          return $ret;
 118      }
 119  
 120      public function shiftLeft($bits=8)
 121      {
 122          $ret = new self();
 123          $ret->_rh = gmp_mul($this->_rh, gmp_pow(2, $bits));
 124          return $ret;
 125      }
 126  
 127      public function absoluteValue()
 128      {
 129          $ret = new self();
 130          $ret->_rh = gmp_abs($this->_rh);
 131          return $ret;
 132      }
 133  }