diff options
Diffstat (limited to 'vendor/phpseclib/phpseclib/phpseclib/Math/BigInteger/Engines/BCMath/Base.php')
-rw-r--r-- | vendor/phpseclib/phpseclib/phpseclib/Math/BigInteger/Engines/BCMath/Base.php | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/vendor/phpseclib/phpseclib/phpseclib/Math/BigInteger/Engines/BCMath/Base.php b/vendor/phpseclib/phpseclib/phpseclib/Math/BigInteger/Engines/BCMath/Base.php new file mode 100644 index 0000000..fe21e04 --- /dev/null +++ b/vendor/phpseclib/phpseclib/phpseclib/Math/BigInteger/Engines/BCMath/Base.php @@ -0,0 +1,110 @@ +<?php + +/** + * Modular Exponentiation Engine + * + * PHP version 5 and 7 + * + * @author Jim Wigginton <[email protected]> + * @copyright 2017 Jim Wigginton + * @license http://www.opensource.org/licenses/mit-license.html MIT License + * @link http://pear.php.net/package/Math_BigInteger + */ + +namespace phpseclib3\Math\BigInteger\Engines\BCMath; + +use phpseclib3\Math\BigInteger\Engines\BCMath; + +/** + * Sliding Window Exponentiation Engine + * + * @author Jim Wigginton <[email protected]> + */ +abstract class Base extends BCMath +{ + /** + * Cache constants + * + * $cache[self::VARIABLE] tells us whether or not the cached data is still valid. + * + */ + const VARIABLE = 0; + /** + * $cache[self::DATA] contains the cached data. + * + */ + const DATA = 1; + + /** + * Test for engine validity + * + * @return bool + */ + public static function isValidEngine() + { + return static::class != __CLASS__; + } + + /** + * Performs modular exponentiation. + * + * @param BCMath $x + * @param BCMath $e + * @param BCMath $n + * @param string $class + * @return BCMath + */ + protected static function powModHelper(BCMath $x, BCMath $e, BCMath $n, $class) + { + if (empty($e->value)) { + $temp = new $class(); + $temp->value = '1'; + return $x->normalize($temp); + } + + return $x->normalize(static::slidingWindow($x, $e, $n, $class)); + } + + /** + * Modular reduction preparation + * + * @param string $x + * @param string $n + * @param string $class + * @see self::slidingWindow() + * @return string + */ + protected static function prepareReduce($x, $n, $class) + { + return static::reduce($x, $n); + } + + /** + * Modular multiply + * + * @param string $x + * @param string $y + * @param string $n + * @param string $class + * @see self::slidingWindow() + * @return string + */ + protected static function multiplyReduce($x, $y, $n, $class) + { + return static::reduce(bcmul($x, $y), $n); + } + + /** + * Modular square + * + * @param string $x + * @param string $n + * @param string $class + * @see self::slidingWindow() + * @return string + */ + protected static function squareReduce($x, $n, $class) + { + return static::reduce(bcmul($x, $x), $n); + } +} |