xref: /dokuwiki/vendor/paragonie/constant_time_encoding/src/Binary.php (revision 850e662095111529d7d330745fee3207907c4aee)
1927933f5SAndreas Gohr<?php
2927933f5SAndreas Gohrdeclare(strict_types=1);
3927933f5SAndreas Gohrnamespace ParagonIE\ConstantTime;
4927933f5SAndreas Gohr
5927933f5SAndreas Gohruse TypeError;
6927933f5SAndreas Gohr
7927933f5SAndreas Gohr/**
8927933f5SAndreas Gohr *  Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
9927933f5SAndreas Gohr *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
10927933f5SAndreas Gohr *
11927933f5SAndreas Gohr *  Permission is hereby granted, free of charge, to any person obtaining a copy
12927933f5SAndreas Gohr *  of this software and associated documentation files (the "Software"), to deal
13927933f5SAndreas Gohr *  in the Software without restriction, including without limitation the rights
14927933f5SAndreas Gohr *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15927933f5SAndreas Gohr *  copies of the Software, and to permit persons to whom the Software is
16927933f5SAndreas Gohr *  furnished to do so, subject to the following conditions:
17927933f5SAndreas Gohr *
18927933f5SAndreas Gohr *  The above copyright notice and this permission notice shall be included in all
19927933f5SAndreas Gohr *  copies or substantial portions of the Software.
20927933f5SAndreas Gohr *
21927933f5SAndreas Gohr *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22927933f5SAndreas Gohr *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23927933f5SAndreas Gohr *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24927933f5SAndreas Gohr *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25927933f5SAndreas Gohr *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26927933f5SAndreas Gohr *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27927933f5SAndreas Gohr *  SOFTWARE.
28927933f5SAndreas Gohr */
29927933f5SAndreas Gohr
30927933f5SAndreas Gohr/**
31927933f5SAndreas Gohr * Class Binary
32927933f5SAndreas Gohr *
33927933f5SAndreas Gohr * Binary string operators that don't choke on
34927933f5SAndreas Gohr * mbstring.func_overload
35927933f5SAndreas Gohr *
36927933f5SAndreas Gohr * @package ParagonIE\ConstantTime
37927933f5SAndreas Gohr */
38927933f5SAndreas Gohrabstract class Binary
39927933f5SAndreas Gohr{
40927933f5SAndreas Gohr    /**
41927933f5SAndreas Gohr     * Safe string length
42927933f5SAndreas Gohr     *
43927933f5SAndreas Gohr     * @ref mbstring.func_overload
44927933f5SAndreas Gohr     *
45927933f5SAndreas Gohr     * @param string $str
46927933f5SAndreas Gohr     * @return int
47927933f5SAndreas Gohr     */
48*850e6620SAndreas Gohr    public static function safeStrlen(
49*850e6620SAndreas Gohr        #[\SensitiveParameter]
50*850e6620SAndreas Gohr        string $str
51*850e6620SAndreas Gohr    ): int {
52927933f5SAndreas Gohr        if (\function_exists('mb_strlen')) {
53927933f5SAndreas Gohr            // mb_strlen in PHP 7.x can return false.
54927933f5SAndreas Gohr            /** @psalm-suppress RedundantCast */
55927933f5SAndreas Gohr            return (int) \mb_strlen($str, '8bit');
56927933f5SAndreas Gohr        } else {
57927933f5SAndreas Gohr            return \strlen($str);
58927933f5SAndreas Gohr        }
59927933f5SAndreas Gohr    }
60927933f5SAndreas Gohr
61927933f5SAndreas Gohr    /**
62927933f5SAndreas Gohr     * Safe substring
63927933f5SAndreas Gohr     *
64927933f5SAndreas Gohr     * @ref mbstring.func_overload
65927933f5SAndreas Gohr     *
66927933f5SAndreas Gohr     * @staticvar boolean $exists
67927933f5SAndreas Gohr     * @param string $str
68927933f5SAndreas Gohr     * @param int $start
69927933f5SAndreas Gohr     * @param ?int $length
70927933f5SAndreas Gohr     * @return string
71927933f5SAndreas Gohr     *
72927933f5SAndreas Gohr     * @throws TypeError
73927933f5SAndreas Gohr     */
74927933f5SAndreas Gohr    public static function safeSubstr(
75*850e6620SAndreas Gohr        #[\SensitiveParameter]
76927933f5SAndreas Gohr        string $str,
77927933f5SAndreas Gohr        int $start = 0,
78927933f5SAndreas Gohr        $length = null
79927933f5SAndreas Gohr    ): string {
80927933f5SAndreas Gohr        if ($length === 0) {
81927933f5SAndreas Gohr            return '';
82927933f5SAndreas Gohr        }
83927933f5SAndreas Gohr        if (\function_exists('mb_substr')) {
84927933f5SAndreas Gohr            return \mb_substr($str, $start, $length, '8bit');
85927933f5SAndreas Gohr        }
86927933f5SAndreas Gohr        // Unlike mb_substr(), substr() doesn't accept NULL for length
87927933f5SAndreas Gohr        if ($length !== null) {
88927933f5SAndreas Gohr            return \substr($str, $start, $length);
89927933f5SAndreas Gohr        } else {
90927933f5SAndreas Gohr            return \substr($str, $start);
91927933f5SAndreas Gohr        }
92927933f5SAndreas Gohr    }
93927933f5SAndreas Gohr}
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