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   1  <?php
   2  
   3  /**
   4   * Curve448
   5   *
   6   * PHP version 5 and 7
   7   *
   8   * @category  Crypt
   9   * @package   EC
  10   * @author    Jim Wigginton <[email protected]>
  11   * @copyright 2019 Jim Wigginton
  12   * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
  13   * @link      http://pear.php.net/package/Math_BigInteger
  14   */
  15  
  16  namespace phpseclib3\Crypt\EC\Curves;
  17  
  18  use phpseclib3\Crypt\EC\BaseCurves\Montgomery;
  19  use phpseclib3\Math\BigInteger;
  20  
  21  class Curve448 extends Montgomery
  22  {
  23      public function __construct()
  24      {
  25          // 2^448 - 2^224 - 1
  26          $this->setModulo(new BigInteger(
  27              'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE' .
  28              'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF',
  29              16
  30          ));
  31          $this->a24 = $this->factory->newInteger(new BigInteger('39081'));
  32          $this->p = [$this->factory->newInteger(new BigInteger(5))];
  33          // 2^446 - 0x8335dc163bb124b65129c96fde933d8d723a70aadc873d6d54a7bb0d
  34          $this->setOrder(new BigInteger(
  35              '3FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF' .
  36              '7CCA23E9C44EDB49AED63690216CC2728DC58F552378C292AB5844F3',
  37              16
  38          ));
  39  
  40          /*
  41          $this->setCoefficients(
  42              new BigInteger('156326'), // a
  43          );
  44          $this->setBasePoint(
  45              new BigInteger(5),
  46              new BigInteger(
  47                  '355293926785568175264127502063783334808976399387714271831880898' .
  48                  '435169088786967410002932673765864550910142774147268105838985595290' .
  49                  '606362')
  50          );
  51          */
  52      }
  53  
  54      /**
  55       * Multiply a point on the curve by a scalar
  56       *
  57       * Modifies the scalar as described at https://tools.ietf.org/html/rfc7748#page-8
  58       *
  59       * @return array
  60       */
  61      public function multiplyPoint(array $p, BigInteger $d)
  62      {
  63          //$r = strrev(sodium_crypto_scalarmult($d->toBytes(), strrev($p[0]->toBytes())));
  64          //return [$this->factory->newInteger(new BigInteger($r, 256))];
  65  
  66          $d = $d->toBytes();
  67          $d[0] = $d[0] & "\xFC";
  68          $d = strrev($d);
  69          $d |= "\x80";
  70          $d = new BigInteger($d, 256);
  71  
  72          return parent::multiplyPoint($p, $d);
  73      }
  74  
  75      /**
  76       * Creates a random scalar multiplier
  77       *
  78       * @return BigInteger
  79       */
  80      public function createRandomMultiplier()
  81      {
  82          return BigInteger::random(446);
  83      }
  84  
  85      /**
  86       * Performs range check
  87       */
  88      public function rangeCheck(BigInteger $x)
  89      {
  90          if ($x->getLength() > 448 || $x->isNegative()) {
  91              throw new \RangeException('x must be a positive integer less than 446 bytes in length');
  92          }
  93      }
  94  }