xref: /dokuwiki/vendor/paragonie/constant_time_encoding/src/Base64DotSlash.php (revision 927933f55f286c8bea68959a13975cbcb59eb8ee)
1*927933f5SAndreas Gohr<?php
2*927933f5SAndreas Gohrdeclare(strict_types=1);
3*927933f5SAndreas Gohrnamespace ParagonIE\ConstantTime;
4*927933f5SAndreas Gohr
5*927933f5SAndreas Gohr/**
6*927933f5SAndreas Gohr *  Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
7*927933f5SAndreas Gohr *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
8*927933f5SAndreas Gohr *
9*927933f5SAndreas Gohr *  Permission is hereby granted, free of charge, to any person obtaining a copy
10*927933f5SAndreas Gohr *  of this software and associated documentation files (the "Software"), to deal
11*927933f5SAndreas Gohr *  in the Software without restriction, including without limitation the rights
12*927933f5SAndreas Gohr *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13*927933f5SAndreas Gohr *  copies of the Software, and to permit persons to whom the Software is
14*927933f5SAndreas Gohr *  furnished to do so, subject to the following conditions:
15*927933f5SAndreas Gohr *
16*927933f5SAndreas Gohr *  The above copyright notice and this permission notice shall be included in all
17*927933f5SAndreas Gohr *  copies or substantial portions of the Software.
18*927933f5SAndreas Gohr *
19*927933f5SAndreas Gohr *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20*927933f5SAndreas Gohr *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21*927933f5SAndreas Gohr *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22*927933f5SAndreas Gohr *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23*927933f5SAndreas Gohr *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24*927933f5SAndreas Gohr *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
25*927933f5SAndreas Gohr *  SOFTWARE.
26*927933f5SAndreas Gohr */
27*927933f5SAndreas Gohr
28*927933f5SAndreas Gohr/**
29*927933f5SAndreas Gohr * Class Base64DotSlash
30*927933f5SAndreas Gohr * ./[A-Z][a-z][0-9]
31*927933f5SAndreas Gohr *
32*927933f5SAndreas Gohr * @package ParagonIE\ConstantTime
33*927933f5SAndreas Gohr */
34*927933f5SAndreas Gohrabstract class Base64DotSlash extends Base64
35*927933f5SAndreas Gohr{
36*927933f5SAndreas Gohr    /**
37*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
38*927933f5SAndreas Gohr     * into 8-bit integers.
39*927933f5SAndreas Gohr     *
40*927933f5SAndreas Gohr     * Base64 character set:
41*927933f5SAndreas Gohr     * ./         [A-Z]      [a-z]     [0-9]
42*927933f5SAndreas Gohr     * 0x2e-0x2f, 0x41-0x5a, 0x61-0x7a, 0x30-0x39
43*927933f5SAndreas Gohr     *
44*927933f5SAndreas Gohr     * @param int $src
45*927933f5SAndreas Gohr     * @return int
46*927933f5SAndreas Gohr     */
47*927933f5SAndreas Gohr    protected static function decode6Bits(int $src): int
48*927933f5SAndreas Gohr    {
49*927933f5SAndreas Gohr        $ret = -1;
50*927933f5SAndreas Gohr
51*927933f5SAndreas Gohr        // if ($src > 0x2d && $src < 0x30) ret += $src - 0x2e + 1; // -45
52*927933f5SAndreas Gohr        $ret += (((0x2d - $src) & ($src - 0x30)) >> 8) & ($src - 45);
53*927933f5SAndreas Gohr
54*927933f5SAndreas Gohr        // if ($src > 0x40 && $src < 0x5b) ret += $src - 0x41 + 2 + 1; // -62
55*927933f5SAndreas Gohr        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 62);
56*927933f5SAndreas Gohr
57*927933f5SAndreas Gohr        // if ($src > 0x60 && $src < 0x7b) ret += $src - 0x61 + 28 + 1; // -68
58*927933f5SAndreas Gohr        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 68);
59*927933f5SAndreas Gohr
60*927933f5SAndreas Gohr        // if ($src > 0x2f && $src < 0x3a) ret += $src - 0x30 + 54 + 1; // 7
61*927933f5SAndreas Gohr        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 7);
62*927933f5SAndreas Gohr
63*927933f5SAndreas Gohr        return $ret;
64*927933f5SAndreas Gohr    }
65*927933f5SAndreas Gohr
66*927933f5SAndreas Gohr    /**
67*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
68*927933f5SAndreas Gohr     * into 6-bit integers.
69*927933f5SAndreas Gohr     *
70*927933f5SAndreas Gohr     * @param int $src
71*927933f5SAndreas Gohr     * @return string
72*927933f5SAndreas Gohr     */
73*927933f5SAndreas Gohr    protected static function encode6Bits(int $src): string
74*927933f5SAndreas Gohr    {
75*927933f5SAndreas Gohr        $src += 0x2e;
76*927933f5SAndreas Gohr
77*927933f5SAndreas Gohr        // if ($src > 0x2f) $src += 0x41 - 0x30; // 17
78*927933f5SAndreas Gohr        $src += ((0x2f - $src) >> 8) & 17;
79*927933f5SAndreas Gohr
80*927933f5SAndreas Gohr        // if ($src > 0x5a) $src += 0x61 - 0x5b; // 6
81*927933f5SAndreas Gohr        $src += ((0x5a - $src) >> 8) & 6;
82*927933f5SAndreas Gohr
83*927933f5SAndreas Gohr        // if ($src > 0x7a) $src += 0x30 - 0x7b; // -75
84*927933f5SAndreas Gohr        $src -= ((0x7a - $src) >> 8) & 75;
85*927933f5SAndreas Gohr
86*927933f5SAndreas Gohr        return \pack('C', $src);
87*927933f5SAndreas Gohr    }
88*927933f5SAndreas Gohr}
89