xref: /dokuwiki/vendor/paragonie/constant_time_encoding/src/Binary.php (revision 927933f55f286c8bea68959a13975cbcb59eb8ee)
1*927933f5SAndreas Gohr<?php
2*927933f5SAndreas Gohrdeclare(strict_types=1);
3*927933f5SAndreas Gohrnamespace ParagonIE\ConstantTime;
4*927933f5SAndreas Gohr
5*927933f5SAndreas Gohruse TypeError;
6*927933f5SAndreas Gohr
7*927933f5SAndreas Gohr/**
8*927933f5SAndreas Gohr *  Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
9*927933f5SAndreas Gohr *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
10*927933f5SAndreas Gohr *
11*927933f5SAndreas Gohr *  Permission is hereby granted, free of charge, to any person obtaining a copy
12*927933f5SAndreas Gohr *  of this software and associated documentation files (the "Software"), to deal
13*927933f5SAndreas Gohr *  in the Software without restriction, including without limitation the rights
14*927933f5SAndreas Gohr *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15*927933f5SAndreas Gohr *  copies of the Software, and to permit persons to whom the Software is
16*927933f5SAndreas Gohr *  furnished to do so, subject to the following conditions:
17*927933f5SAndreas Gohr *
18*927933f5SAndreas Gohr *  The above copyright notice and this permission notice shall be included in all
19*927933f5SAndreas Gohr *  copies or substantial portions of the Software.
20*927933f5SAndreas Gohr *
21*927933f5SAndreas Gohr *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22*927933f5SAndreas Gohr *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23*927933f5SAndreas Gohr *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24*927933f5SAndreas Gohr *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25*927933f5SAndreas Gohr *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26*927933f5SAndreas Gohr *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27*927933f5SAndreas Gohr *  SOFTWARE.
28*927933f5SAndreas Gohr */
29*927933f5SAndreas Gohr
30*927933f5SAndreas Gohr/**
31*927933f5SAndreas Gohr * Class Binary
32*927933f5SAndreas Gohr *
33*927933f5SAndreas Gohr * Binary string operators that don't choke on
34*927933f5SAndreas Gohr * mbstring.func_overload
35*927933f5SAndreas Gohr *
36*927933f5SAndreas Gohr * @package ParagonIE\ConstantTime
37*927933f5SAndreas Gohr */
38*927933f5SAndreas Gohrabstract class Binary
39*927933f5SAndreas Gohr{
40*927933f5SAndreas Gohr    /**
41*927933f5SAndreas Gohr     * Safe string length
42*927933f5SAndreas Gohr     *
43*927933f5SAndreas Gohr     * @ref mbstring.func_overload
44*927933f5SAndreas Gohr     *
45*927933f5SAndreas Gohr     * @param string $str
46*927933f5SAndreas Gohr     * @return int
47*927933f5SAndreas Gohr     */
48*927933f5SAndreas Gohr    public static function safeStrlen(string $str): int
49*927933f5SAndreas Gohr    {
50*927933f5SAndreas Gohr        if (\function_exists('mb_strlen')) {
51*927933f5SAndreas Gohr            // mb_strlen in PHP 7.x can return false.
52*927933f5SAndreas Gohr            /** @psalm-suppress RedundantCast */
53*927933f5SAndreas Gohr            return (int) \mb_strlen($str, '8bit');
54*927933f5SAndreas Gohr        } else {
55*927933f5SAndreas Gohr            return \strlen($str);
56*927933f5SAndreas Gohr        }
57*927933f5SAndreas Gohr    }
58*927933f5SAndreas Gohr
59*927933f5SAndreas Gohr    /**
60*927933f5SAndreas Gohr     * Safe substring
61*927933f5SAndreas Gohr     *
62*927933f5SAndreas Gohr     * @ref mbstring.func_overload
63*927933f5SAndreas Gohr     *
64*927933f5SAndreas Gohr     * @staticvar boolean $exists
65*927933f5SAndreas Gohr     * @param string $str
66*927933f5SAndreas Gohr     * @param int $start
67*927933f5SAndreas Gohr     * @param ?int $length
68*927933f5SAndreas Gohr     * @return string
69*927933f5SAndreas Gohr     *
70*927933f5SAndreas Gohr     * @throws TypeError
71*927933f5SAndreas Gohr     */
72*927933f5SAndreas Gohr    public static function safeSubstr(
73*927933f5SAndreas Gohr        string $str,
74*927933f5SAndreas Gohr        int $start = 0,
75*927933f5SAndreas Gohr        $length = null
76*927933f5SAndreas Gohr    ): string {
77*927933f5SAndreas Gohr        if ($length === 0) {
78*927933f5SAndreas Gohr            return '';
79*927933f5SAndreas Gohr        }
80*927933f5SAndreas Gohr        if (\function_exists('mb_substr')) {
81*927933f5SAndreas Gohr            return \mb_substr($str, $start, $length, '8bit');
82*927933f5SAndreas Gohr        }
83*927933f5SAndreas Gohr        // Unlike mb_substr(), substr() doesn't accept NULL for length
84*927933f5SAndreas Gohr        if ($length !== null) {
85*927933f5SAndreas Gohr            return \substr($str, $start, $length);
86*927933f5SAndreas Gohr        } else {
87*927933f5SAndreas Gohr            return \substr($str, $start);
88*927933f5SAndreas Gohr        }
89*927933f5SAndreas Gohr    }
90*927933f5SAndreas Gohr}
91