Curve25519.php — JetBackup – Backup, Restore & Migrate trunk

backup / src / JetBackup / 3rdparty / phpseclib3 / Crypt / EC / Curves / Curve25519.php

backup / src / JetBackup / 3rdparty / phpseclib3 / Crypt / EC / Curves Last commit date

Curve25519.php

81 lines

1	<?php
2
3	/**
4	* Curve25519
5	*
6	* PHP version 5 and 7
7	*
8	* @author Jim Wigginton <terrafrost@php.net>
9	* @copyright 2019 Jim Wigginton
10	* @license http://www.opensource.org/licenses/mit-license.html MIT License
11	* @link http://pear.php.net/package/Math_BigInteger
12	*/
13
14	declare(strict_types=1);
15
16	namespace phpseclib3\Crypt\EC\Curves;
17
18	use phpseclib3\Crypt\EC\BaseCurves\Montgomery;
19	use phpseclib3\Exception\RangeException;
20	use phpseclib3\Math\BigInteger;
21
22	class Curve25519 extends Montgomery
23	{
24	public function __construct()
25	{
26	// 2^255 - 19
27	$this->setModulo(new BigInteger('7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED', 16));
28	$this->a24 = $this->factory->newInteger(new BigInteger('121666'));
29	$this->p = [$this->factory->newInteger(new BigInteger(9))];
30	// 2^252 + 0x14def9dea2f79cd65812631a5cf5d3ed
31	$this->setOrder(new BigInteger('1000000000000000000000000000000014DEF9DEA2F79CD65812631A5CF5D3ED', 16));
32
33	/*
34	$this->setCoefficients(
35	new BigInteger('486662'), // a
36	);
37	$this->setBasePoint(
38	new BigInteger(9),
39	new BigInteger('14781619447589544791020593568409986887264606134616475288964881837755586237401')
40	);
41	*/
42	}
43
44	/**
45	* Multiply a point on the curve by a scalar
46	*
47	* Modifies the scalar as described at https://tools.ietf.org/html/rfc7748#page-8
48	*/
49	public function multiplyPoint(array $p, BigInteger $d): array
50	{
51	//$r = strrev(sodium_crypto_scalarmult($d->toBytes(), strrev($p[0]->toBytes())));
52	//return [$this->factory->newInteger(new BigInteger($r, 256))];
53
54	$d = $d->toBytes();
55	$d &= "\xF8" . str_repeat("\xFF", 30) . "\x7F";
56	$d = strrev($d);
57	$d \|= "\x40";
58	$d = new BigInteger($d, -256);
59
60	return parent::multiplyPoint($p, $d);
61	}
62
63	/**
64	* Creates a random scalar multiplier
65	*/
66	public function createRandomMultiplier(): BigInteger
67	{
68	return BigInteger::random(256);
69	}
70
71	/**
72	* Performs range check
73	*/
74	public function rangeCheck(BigInteger $x): void
75	{
76	if ($x->getLength() > 256 \|\| $x->isNegative()) {
77	throw new RangeException('x must be a positive integer less than 256 bytes in length');
78	}
79	}
80	}
81