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googleanalytics / lib / analytics-admin / vendor / paragonie / constant_time_encoding / src / Hex.php

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Base32.php 3 years ago Base32Hex.php 3 years ago Base64.php 3 years ago Base64DotSlash.php 3 years ago Base64DotSlashOrdered.php 3 years ago Base64UrlSafe.php 3 years ago Binary.php 3 years ago EncoderInterface.php 3 years ago Encoding.php 3 years ago Hex.php 3 years ago RFC4648.php 3 years ago

Hex.php

147 lines

1	<?php
2	declare(strict_types=1);
3	namespace ParagonIE\ConstantTime;
4
5	use RangeException;
6	use TypeError;
7
8	/**
9	* Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
10	* Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
11	*
12	* Permission is hereby granted, free of charge, to any person obtaining a copy
13	* of this software and associated documentation files (the "Software"), to deal
14	* in the Software without restriction, including without limitation the rights
15	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
16	* copies of the Software, and to permit persons to whom the Software is
17	* furnished to do so, subject to the following conditions:
18	*
19	* The above copyright notice and this permission notice shall be included in all
20	* copies or substantial portions of the Software.
21	*
22	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
25	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
27	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
28	* SOFTWARE.
29	*/
30
31	/**
32	* Class Hex
33	* @package ParagonIE\ConstantTime
34	*/
35	abstract class Hex implements EncoderInterface
36	{
37	/**
38	* Convert a binary string into a hexadecimal string without cache-timing
39	* leaks
40	*
41	* @param string $binString (raw binary)
42	* @return string
43	* @throws TypeError
44	*/
45	public static function encode(string $binString): string
46	{
47	$hex = '';
48	$len = Binary::safeStrlen($binString);
49	for ($i = 0; $i < $len; ++$i) {
50	/** @var array<int, int> $chunk */
51	$chunk = \unpack('C', $binString[$i]);
52	$c = $chunk[1] & 0xf;
53	$b = $chunk[1] >> 4;
54
55	$hex .= \pack(
56	'CC',
57	(87 + $b + ((($b - 10) >> 8) & ~38)),
58	(87 + $c + ((($c - 10) >> 8) & ~38))
59	);
60	}
61	return $hex;
62	}
63
64	/**
65	* Convert a binary string into a hexadecimal string without cache-timing
66	* leaks, returning uppercase letters (as per RFC 4648)
67	*
68	* @param string $binString (raw binary)
69	* @return string
70	* @throws TypeError
71	*/
72	public static function encodeUpper(string $binString): string
73	{
74	$hex = '';
75	$len = Binary::safeStrlen($binString);
76
77	for ($i = 0; $i < $len; ++$i) {
78	/** @var array<int, int> $chunk */
79	$chunk = \unpack('C', $binString[$i]);
80	$c = $chunk[1] & 0xf;
81	$b = $chunk[1] >> 4;
82
83	$hex .= \pack(
84	'CC',
85	(55 + $b + ((($b - 10) >> 8) & ~6)),
86	(55 + $c + ((($c - 10) >> 8) & ~6))
87	);
88	}
89	return $hex;
90	}
91
92	/**
93	* Convert a hexadecimal string into a binary string without cache-timing
94	* leaks
95	*
96	* @param string $encodedString
97	* @param bool $strictPadding
98	* @return string (raw binary)
99	* @throws RangeException
100	*/
101	public static function decode(
102	string $encodedString,
103	bool $strictPadding = false
104	): string {
105	$hex_pos = 0;
106	$bin = '';
107	$c_acc = 0;
108	$hex_len = Binary::safeStrlen($encodedString);
109	$state = 0;
110	if (($hex_len & 1) !== 0) {
111	if ($strictPadding) {
112	throw new RangeException(
113	'Expected an even number of hexadecimal characters'
114	);
115	} else {
116	$encodedString = '0' . $encodedString;
117	++$hex_len;
118	}
119	}
120
121	/** @var array<int, int> $chunk */
122	$chunk = \unpack('C*', $encodedString);
123	while ($hex_pos < $hex_len) {
124	++$hex_pos;
125	$c = $chunk[$hex_pos];
126	$c_num = $c ^ 48;
127	$c_num0 = ($c_num - 10) >> 8;
128	$c_alpha = ($c & ~32) - 55;
129	$c_alpha0 = (($c_alpha - 10) ^ ($c_alpha - 16)) >> 8;
130
131	if (($c_num0 \| $c_alpha0) === 0) {
132	throw new RangeException(
133	'Expected hexadecimal character'
134	);
135	}
136	$c_val = ($c_num0 & $c_num) \| ($c_alpha & $c_alpha0);
137	if ($state === 0) {
138	$c_acc = $c_val * 16;
139	} else {
140	$bin .= \pack('C', $c_acc \| $c_val);
141	}
142	$state ^= 1;
143	}
144	return $bin;
145	}
146	}
147