Rev 846 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 827 | daniel-mar | 1 | <?php |
| 2 | |||
| 3 | /** |
||
| 4 | * PHP Power of Two Modular Exponentiation Engine |
||
| 5 | * |
||
| 6 | * PHP version 5 and 7 |
||
| 7 | * |
||
| 874 | daniel-mar | 8 | * @category Math |
| 9 | * @package BigInteger |
||
| 827 | daniel-mar | 10 | * @author Jim Wigginton <terrafrost@php.net> |
| 11 | * @copyright 2017 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\Math\BigInteger\Engines\PHP\Reductions; |
||
| 17 | |||
| 18 | use phpseclib3\Math\BigInteger\Engines\PHP\Base; |
||
| 19 | |||
| 20 | /** |
||
| 21 | * PHP Power Of Two Modular Exponentiation Engine |
||
| 22 | * |
||
| 874 | daniel-mar | 23 | * @package PHP |
| 827 | daniel-mar | 24 | * @author Jim Wigginton <terrafrost@php.net> |
| 874 | daniel-mar | 25 | * @access public |
| 827 | daniel-mar | 26 | */ |
| 27 | abstract class PowerOfTwo extends Base |
||
| 28 | { |
||
| 29 | /** |
||
| 30 | * Prepare a number for use in Montgomery Modular Reductions |
||
| 31 | * |
||
| 32 | * @param array $x |
||
| 33 | * @param array $n |
||
| 34 | * @param string $class |
||
| 35 | * @return array |
||
| 36 | */ |
||
| 37 | protected static function prepareReduce(array $x, array $n, $class) |
||
| 38 | { |
||
| 39 | return self::reduce($x, $n, $class); |
||
| 40 | } |
||
| 41 | |||
| 42 | /** |
||
| 43 | * Power Of Two Reduction |
||
| 44 | * |
||
| 45 | * @param array $x |
||
| 46 | * @param array $n |
||
| 47 | * @param string $class |
||
| 48 | * @return array |
||
| 49 | */ |
||
| 50 | protected static function reduce(array $x, array $n, $class) |
||
| 51 | { |
||
| 52 | $lhs = new $class(); |
||
| 53 | $lhs->value = $x; |
||
| 54 | $rhs = new $class(); |
||
| 55 | $rhs->value = $n; |
||
| 56 | |||
| 57 | $temp = new $class(); |
||
| 58 | $temp->value = [1]; |
||
| 59 | |||
| 60 | $result = $lhs->bitwise_and($rhs->subtract($temp)); |
||
| 61 | return $result->value; |
||
| 62 | } |
||
| 63 | } |