secp192r1.php — JetBackup – Backup, Restore & Migrate trunk

backup / src / JetBackup / 3rdparty / phpseclib3 / Crypt / EC / Curves / secp192r1.php

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

secp192r1.php

81 lines

1	<?php
2
3	/**
4	* secp192r1
5	*
6	* This is the NIST P-192 curve
7	*
8	* PHP version 5 and 7
9	*
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	declare(strict_types=1);
17
18	namespace phpseclib3\Crypt\EC\Curves;
19
20	use phpseclib3\Crypt\EC\BaseCurves\Prime;
21	use phpseclib3\Math\BigInteger;
22
23	class secp192r1 extends Prime
24	{
25	public function __construct()
26	{
27	$modulo = new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF', 16);
28	$this->setModulo($modulo);
29
30	// algorithm 2.27 from http://diamond.boisestate.edu/~liljanab/MATH308/GuideToECC.pdf#page=66
31	/* in theory this should be faster than regular modular reductions save for one small issue.
32	to convert to / from base-2**8 with BCMath you have to call bcmul() and bcdiv() a lot.
33	to convert to / from base-2**8 with PHP64 you have to call base256_rshift() a lot.
34	in short, converting to / from base-2**8 is pretty expensive and that expense is
35	enough to offset whatever else might be gained by a simplified reduction algorithm.
36	now, if PHP supported unsigned integers things might be different. no bit-shifting
37	would be required for the PHP engine and it'd be a lot faster. but as is, BigInteger
38	uses base-231 or base-226 depending on whether or not the system is has a 32-bit
39	or a 64-bit OS.
40	*/
41	/*
42	$m_length = $this->getLengthInBytes();
43	$this->setReduction(function($c) use ($m_length) {
44	$cBytes = $c->toBytes();
45	$className = $this->className;
46
47	if (strlen($cBytes) > 2 * $m_length) {
48	list(, $r) = $c->divide($className::$modulo);
49	return $r;
50	}
51
52	$c = str_pad($cBytes, 48, "\0", STR_PAD_LEFT);
53	$c = array_reverse(str_split($c, 8));
54
55	$null = "\0\0\0\0\0\0\0\0";
56	$s1 = new BigInteger($c[2] . $c[1] . $c[0], 256);
57	$s2 = new BigInteger($null . $c[3] . $c[3], 256);
58	$s3 = new BigInteger($c[4] . $c[4] . $null, 256);
59	$s4 = new BigInteger($c[5] . $c[5] . $c[5], 256);
60
61	$r = $s1->add($s2)->add($s3)->add($s4);
62	while ($r->compare($className::$modulo) >= 0) {
63	$r = $r->subtract($className::$modulo);
64	}
65
66	return $r;
67	});
68	*/
69
70	$this->setCoefficients(
71	new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFC', 16),
72	new BigInteger('64210519E59C80E70FA7E9AB72243049FEB8DEECC146B9B1', 16)
73	);
74	$this->setBasePoint(
75	new BigInteger('188DA80EB03090F67CBF20EB43A18800F4FF0AFD82FF1012', 16),
76	new BigInteger('07192B95FFC8DA78631011ED6B24CDD573F977A11E794811', 16)
77	);
78	$this->setOrder(new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFF99DEF836146BC9B1B4D22831', 16));
79	}
80	}
81