xref: /dokuwiki/vendor/paragonie/constant_time_encoding/src/Base32Hex.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 Base32Hex
30*927933f5SAndreas Gohr * [0-9][A-V]
31*927933f5SAndreas Gohr *
32*927933f5SAndreas Gohr * @package ParagonIE\ConstantTime
33*927933f5SAndreas Gohr */
34*927933f5SAndreas Gohrabstract class Base32Hex extends Base32
35*927933f5SAndreas Gohr{
36*927933f5SAndreas Gohr    /**
37*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
38*927933f5SAndreas Gohr     * into 8-bit integers.
39*927933f5SAndreas Gohr     *
40*927933f5SAndreas Gohr     * @param int $src
41*927933f5SAndreas Gohr     * @return int
42*927933f5SAndreas Gohr     */
43*927933f5SAndreas Gohr    protected static function decode5Bits(int $src): int
44*927933f5SAndreas Gohr    {
45*927933f5SAndreas Gohr        $ret = -1;
46*927933f5SAndreas Gohr
47*927933f5SAndreas Gohr        // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
48*927933f5SAndreas Gohr        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
49*927933f5SAndreas Gohr
50*927933f5SAndreas Gohr        // if ($src > 0x60 && $src < 0x77) ret += $src - 0x61 + 10 + 1; // -86
51*927933f5SAndreas Gohr        $ret += (((0x60 - $src) & ($src - 0x77)) >> 8) & ($src - 86);
52*927933f5SAndreas Gohr
53*927933f5SAndreas Gohr        return $ret;
54*927933f5SAndreas Gohr    }
55*927933f5SAndreas Gohr
56*927933f5SAndreas Gohr    /**
57*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
58*927933f5SAndreas Gohr     * into 8-bit integers.
59*927933f5SAndreas Gohr     *
60*927933f5SAndreas Gohr     * @param int $src
61*927933f5SAndreas Gohr     * @return int
62*927933f5SAndreas Gohr     */
63*927933f5SAndreas Gohr    protected static function decode5BitsUpper(int $src): int
64*927933f5SAndreas Gohr    {
65*927933f5SAndreas Gohr        $ret = -1;
66*927933f5SAndreas Gohr
67*927933f5SAndreas Gohr        // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
68*927933f5SAndreas Gohr        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
69*927933f5SAndreas Gohr
70*927933f5SAndreas Gohr        // if ($src > 0x40 && $src < 0x57) ret += $src - 0x41 + 10 + 1; // -54
71*927933f5SAndreas Gohr        $ret += (((0x40 - $src) & ($src - 0x57)) >> 8) & ($src - 54);
72*927933f5SAndreas Gohr
73*927933f5SAndreas Gohr        return $ret;
74*927933f5SAndreas Gohr    }
75*927933f5SAndreas Gohr
76*927933f5SAndreas Gohr    /**
77*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
78*927933f5SAndreas Gohr     * into 5-bit integers.
79*927933f5SAndreas Gohr     *
80*927933f5SAndreas Gohr     * @param int $src
81*927933f5SAndreas Gohr     * @return string
82*927933f5SAndreas Gohr     */
83*927933f5SAndreas Gohr    protected static function encode5Bits(int $src): string
84*927933f5SAndreas Gohr    {
85*927933f5SAndreas Gohr        $src += 0x30;
86*927933f5SAndreas Gohr
87*927933f5SAndreas Gohr        // if ($src > 0x39) $src += 0x61 - 0x3a; // 39
88*927933f5SAndreas Gohr        $src += ((0x39 - $src) >> 8) & 39;
89*927933f5SAndreas Gohr
90*927933f5SAndreas Gohr        return \pack('C', $src);
91*927933f5SAndreas Gohr    }
92*927933f5SAndreas Gohr
93*927933f5SAndreas Gohr    /**
94*927933f5SAndreas Gohr     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
95*927933f5SAndreas Gohr     * into 5-bit integers.
96*927933f5SAndreas Gohr     *
97*927933f5SAndreas Gohr     * Uppercase variant.
98*927933f5SAndreas Gohr     *
99*927933f5SAndreas Gohr     * @param int $src
100*927933f5SAndreas Gohr     * @return string
101*927933f5SAndreas Gohr     */
102*927933f5SAndreas Gohr    protected static function encode5BitsUpper(int $src): string
103*927933f5SAndreas Gohr    {
104*927933f5SAndreas Gohr        $src += 0x30;
105*927933f5SAndreas Gohr
106*927933f5SAndreas Gohr        // if ($src > 0x39) $src += 0x41 - 0x3a; // 7
107*927933f5SAndreas Gohr        $src += ((0x39 - $src) >> 8) & 7;
108*927933f5SAndreas Gohr
109*927933f5SAndreas Gohr        return \pack('C', $src);
110*927933f5SAndreas Gohr    }
111*927933f5SAndreas Gohr}