<?php
declare(strict_types=1);
/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2018 Spomky-Labs
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*/
namespace Jose\Component\Core\Util\Ecc;
/**
* *********************************************************************
* Copyright (C) 2012 Matyas Danter.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
* ***********************************************************************
*/
/**
* @internal
*/
class Point
{
/**
* @var \GMP
*/
private $x;
/**
* @var \GMP
*/
private $y;
/**
* @var \GMP
*/
private $order;
/**
* @var bool
*/
private $infinity = false;
/**
* Initialize a new instance.
*
* @throws \RuntimeException when either the curve does not contain the given coordinates or
* when order is not null and P(x, y) * order is not equal to infinity
*/
private function __construct(\GMP $x, \GMP $y, \GMP $order, bool $infinity = false)
{
$this->x = $x;
$this->y = $y;
$this->order = $order;
$this->infinity = $infinity;
}
/**
* @return Point
*/
public static function create(\GMP $x, \GMP $y, ?\GMP $order = null): self
{
return new self($x, $y, null === $order ? \gmp_init(0, 10) : $order);
}
/**
* @return Point
*/
public static function infinity(): self
{
$zero = \gmp_init(0, 10);
return new self($zero, $zero, $zero, true);
}
public function isInfinity(): bool
{
return $this->infinity;
}
public function getOrder(): \GMP
{
return $this->order;
}
public function getX(): \GMP
{
return $this->x;
}
public function getY(): \GMP
{
return $this->y;
}
/**
* @param Point $a
* @param Point $b
*/
public static function cswap(self $a, self $b, int $cond)
{
self::cswapGMP($a->x, $b->x, $cond);
self::cswapGMP($a->y, $b->y, $cond);
self::cswapGMP($a->order, $b->order, $cond);
self::cswapBoolean($a->infinity, $b->infinity, $cond);
}
private static function cswapBoolean(bool &$a, bool &$b, int $cond)
{
$sa = \gmp_init((int) ($a), 10);
$sb = \gmp_init((int) ($b), 10);
self::cswapGMP($sa, $sb, $cond);
$a = (bool) \gmp_strval($sa, 10);
$b = (bool) \gmp_strval($sb, 10);
}
private static function cswapGMP(\GMP &$sa, \GMP &$sb, int $cond)
{
$size = \max(\mb_strlen(\gmp_strval($sa, 2), '8bit'), \mb_strlen(\gmp_strval($sb, 2), '8bit'));
$mask = (string) (1 - (int) ($cond));
$mask = \str_pad('', $size, $mask, STR_PAD_LEFT);
$mask = \gmp_init($mask, 2);
$taA = Math::bitwiseAnd($sa, $mask);
$taB = Math::bitwiseAnd($sb, $mask);
$sa = Math::bitwiseXor(Math::bitwiseXor($sa, $sb), $taB);
$sb = Math::bitwiseXor(Math::bitwiseXor($sa, $sb), $taA);
$sa = Math::bitwiseXor(Math::bitwiseXor($sa, $sb), $taB);
}
}