xref: /dokuwiki/vendor/paragonie/constant_time_encoding/src/Base64UrlSafe.php (revision 8e88a29b81301f78509349ab1152bb09c229123e)
1927933f5SAndreas Gohr<?php
2927933f5SAndreas Gohrdeclare(strict_types=1);
3927933f5SAndreas Gohrnamespace ParagonIE\ConstantTime;
4927933f5SAndreas Gohr
5*8e88a29bSAndreas Gohruse Override;
6*8e88a29bSAndreas 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 Base64UrlSafe
32927933f5SAndreas Gohr * [A-Z][a-z][0-9]\-_
33927933f5SAndreas Gohr *
34927933f5SAndreas Gohr * @package ParagonIE\ConstantTime
35927933f5SAndreas Gohr */
36927933f5SAndreas Gohrabstract class Base64UrlSafe extends Base64
37927933f5SAndreas Gohr{
38927933f5SAndreas Gohr
39927933f5SAndreas Gohr    /**
40927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
41927933f5SAndreas Gohr     * into 8-bit integers.
42927933f5SAndreas Gohr     *
43927933f5SAndreas Gohr     * Base64 character set:
44927933f5SAndreas Gohr     * [A-Z]      [a-z]      [0-9]      -     _
45927933f5SAndreas Gohr     * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2d, 0x5f
46927933f5SAndreas Gohr     *
47927933f5SAndreas Gohr     * @param int $src
48927933f5SAndreas Gohr     * @return int
49927933f5SAndreas Gohr     */
50*8e88a29bSAndreas Gohr    #[Override]
51927933f5SAndreas Gohr    protected static function decode6Bits(int $src): int
52927933f5SAndreas Gohr    {
53927933f5SAndreas Gohr        $ret = -1;
54927933f5SAndreas Gohr
55927933f5SAndreas Gohr        // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64
56927933f5SAndreas Gohr        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
57927933f5SAndreas Gohr
58927933f5SAndreas Gohr        // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70
59927933f5SAndreas Gohr        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70);
60927933f5SAndreas Gohr
61927933f5SAndreas Gohr        // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5
62927933f5SAndreas Gohr        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5);
63927933f5SAndreas Gohr
64927933f5SAndreas Gohr        // if ($src == 0x2c) $ret += 62 + 1;
65927933f5SAndreas Gohr        $ret += (((0x2c - $src) & ($src - 0x2e)) >> 8) & 63;
66927933f5SAndreas Gohr
67927933f5SAndreas Gohr        // if ($src == 0x5f) ret += 63 + 1;
68927933f5SAndreas Gohr        $ret += (((0x5e - $src) & ($src - 0x60)) >> 8) & 64;
69927933f5SAndreas Gohr
70927933f5SAndreas Gohr        return $ret;
71927933f5SAndreas Gohr    }
72927933f5SAndreas Gohr
73927933f5SAndreas Gohr    /**
74927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
75927933f5SAndreas Gohr     * into 6-bit integers.
76927933f5SAndreas Gohr     *
77927933f5SAndreas Gohr     * @param int $src
78927933f5SAndreas Gohr     * @return string
79927933f5SAndreas Gohr     */
80*8e88a29bSAndreas Gohr    #[Override]
81927933f5SAndreas Gohr    protected static function encode6Bits(int $src): string
82927933f5SAndreas Gohr    {
83927933f5SAndreas Gohr        $diff = 0x41;
84927933f5SAndreas Gohr
85927933f5SAndreas Gohr        // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6
86927933f5SAndreas Gohr        $diff += ((25 - $src) >> 8) & 6;
87927933f5SAndreas Gohr
88927933f5SAndreas Gohr        // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75
89927933f5SAndreas Gohr        $diff -= ((51 - $src) >> 8) & 75;
90927933f5SAndreas Gohr
91927933f5SAndreas Gohr        // if ($src > 61) $diff += 0x2d - 0x30 - 10; // -13
92927933f5SAndreas Gohr        $diff -= ((61 - $src) >> 8) & 13;
93927933f5SAndreas Gohr
94927933f5SAndreas Gohr        // if ($src > 62) $diff += 0x5f - 0x2b - 1; // 3
95927933f5SAndreas Gohr        $diff += ((62 - $src) >> 8) & 49;
96927933f5SAndreas Gohr
97927933f5SAndreas Gohr        return \pack('C', $src + $diff);
98927933f5SAndreas Gohr    }
99927933f5SAndreas Gohr}
100