defender-security / vendor / web-auth / cose-lib / src / Algorithm / Signature / ECDSA / ECSignature.php

ECSignature.php in Defender Security – Malware Scanner, Login Security & Firewall 5.3.1, at vendor/web-auth/cose-lib/src/Algorithm/Signature/ECDSA/ECSignature.php

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1	<?php
2
3	declare(strict_types=1);
4
5	/*
6	* The MIT License (MIT)
7	*
8	* Copyright (c) 2014-2021 Spomky-Labs
9	*
10	* This software may be modified and distributed under the terms
11	* of the MIT license. See the LICENSE file for details.
12	*/
13
14	namespace Cose\Algorithm\Signature\ECDSA;
15
16	use function bin2hex;
17	use function dechex;
18	use function hexdec;
19	use InvalidArgumentException;
20	use function mb_strlen;
21	use function mb_substr;
22	use function str_pad;
23	use const STR_PAD_LEFT;
24
25	/**
26	* @internal
27	*/
28	final class ECSignature
29	{
30	private const ASN1_SEQUENCE = '30';
31	private const ASN1_INTEGER = '02';
32	private const ASN1_MAX_SINGLE_BYTE = 128;
33	private const ASN1_LENGTH_2BYTES = '81';
34	private const ASN1_BIG_INTEGER_LIMIT = '7f';
35	private const ASN1_NEGATIVE_INTEGER = '00';
36	private const BYTE_SIZE = 2;
37
38	public static function toAsn1(string $signature, int $length): string
39	{
40	$signature = bin2hex($signature);
41
42	if (self::octetLength($signature) !== $length) {
43	throw new InvalidArgumentException('Invalid signature length.');
44	}
45
46	$pointR = self::preparePositiveInteger(mb_substr($signature, 0, $length, '8bit'));
47	$pointS = self::preparePositiveInteger(mb_substr($signature, $length, null, '8bit'));
48
49	$lengthR = self::octetLength($pointR);
50	$lengthS = self::octetLength($pointS);
51
52	$totalLength = $lengthR + $lengthS + self::BYTE_SIZE + self::BYTE_SIZE;
53	$lengthPrefix = $totalLength > self::ASN1_MAX_SINGLE_BYTE ? self::ASN1_LENGTH_2BYTES : '';
54
55	$bin = hex2bin(
56	self::ASN1_SEQUENCE
57	.$lengthPrefix.dechex($totalLength)
58	.self::ASN1_INTEGER.dechex($lengthR).$pointR
59	.self::ASN1_INTEGER.dechex($lengthS).$pointS
60	);
61	if (false === $bin) {
62	throw new InvalidArgumentException('Unable to convert into ASN.1');
63	}
64
65	return $bin;
66	}
67
68	public static function fromAsn1(string $signature, int $length): string
69	{
70	$message = bin2hex($signature);
71	$position = 0;
72
73	if (self::ASN1_SEQUENCE !== self::readAsn1Content($message, $position, self::BYTE_SIZE)) {
74	throw new InvalidArgumentException('Invalid data. Should start with a sequence.');
75	}
76
77	// @phpstan-ignore-next-line
78	if (self::ASN1_LENGTH_2BYTES === self::readAsn1Content($message, $position, self::BYTE_SIZE)) {
79	$position += self::BYTE_SIZE;
80	}
81
82	$pointR = self::retrievePositiveInteger(self::readAsn1Integer($message, $position));
83	$pointS = self::retrievePositiveInteger(self::readAsn1Integer($message, $position));
84
85	$bin = hex2bin(str_pad($pointR, $length, '0', STR_PAD_LEFT).str_pad($pointS, $length, '0', STR_PAD_LEFT));
86	if (false === $bin) {
87	throw new InvalidArgumentException('Unable to convert from ASN.1');
88	}
89
90	return $bin;
91	}
92
93	private static function octetLength(string $data): int
94	{
95	return intdiv(mb_strlen($data, '8bit'), self::BYTE_SIZE);
96	}
97
98	private static function preparePositiveInteger(string $data): string
99	{
100	if (mb_substr($data, 0, self::BYTE_SIZE, '8bit') > self::ASN1_BIG_INTEGER_LIMIT) {
101	return self::ASN1_NEGATIVE_INTEGER.$data;
102	}
103
104	while (
105	self::ASN1_NEGATIVE_INTEGER === mb_substr($data, 0, self::BYTE_SIZE, '8bit')
106	&& mb_substr($data, 2, self::BYTE_SIZE, '8bit') <= self::ASN1_BIG_INTEGER_LIMIT
107	) {
108	$data = mb_substr($data, 2, null, '8bit');
109	}
110
111	return $data;
112	}
113
114	private static function readAsn1Content(string $message, int &$position, int $length): string
115	{
116	$content = mb_substr($message, $position, $length, '8bit');
117	$position += $length;
118
119	return $content;
120	}
121
122	private static function readAsn1Integer(string $message, int &$position): string
123	{
124	if (self::ASN1_INTEGER !== self::readAsn1Content($message, $position, self::BYTE_SIZE)) {
125	throw new InvalidArgumentException('Invalid data. Should contain an integer.');
126	}
127
128	$length = (int) hexdec(self::readAsn1Content($message, $position, self::BYTE_SIZE));
129
130	return self::readAsn1Content($message, $position, $length * self::BYTE_SIZE);
131	}
132
133	private static function retrievePositiveInteger(string $data): string
134	{
135	while (
136	self::ASN1_NEGATIVE_INTEGER === mb_substr($data, 0, self::BYTE_SIZE, '8bit')
137	&& mb_substr($data, 2, self::BYTE_SIZE, '8bit') > self::ASN1_BIG_INTEGER_LIMIT
138	) {
139	$data = mb_substr($data, 2, null, '8bit');
140	}
141
142	return $data;
143	}
144	}
145