Subversion Repositories oidplus

Rev

Rev 827 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
827 daniel-mar 1
<?php
2
declare(strict_types=1);
3
namespace ParagonIE\ConstantTime;
4
 
5
/**
874 daniel-mar 6
 *  Copyright (c) 2016 - 2022 Paragon Initiative Enterprises.
827 daniel-mar 7
 *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
8
 *
9
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
10
 *  of this software and associated documentation files (the "Software"), to deal
11
 *  in the Software without restriction, including without limitation the rights
12
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13
 *  copies of the Software, and to permit persons to whom the Software is
14
 *  furnished to do so, subject to the following conditions:
15
 *
16
 *  The above copyright notice and this permission notice shall be included in all
17
 *  copies or substantial portions of the Software.
18
 *
19
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
25
 *  SOFTWARE.
26
 */
27
 
28
/**
29
 * Class Base64DotSlashOrdered
30
 * ./[0-9][A-Z][a-z]
31
 *
32
 * @package ParagonIE\ConstantTime
33
 */
34
abstract class Base64DotSlashOrdered extends Base64
35
{
36
    /**
37
     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
38
     * into 8-bit integers.
39
     *
40
     * Base64 character set:
41
     * [.-9]      [A-Z]      [a-z]
42
     * 0x2e-0x39, 0x41-0x5a, 0x61-0x7a
43
     *
44
     * @param int $src
45
     * @return int
46
     */
47
    protected static function decode6Bits(int $src): int
48
    {
49
        $ret = -1;
50
 
51
        // if ($src > 0x2d && $src < 0x3a) ret += $src - 0x2e + 1; // -45
52
        $ret += (((0x2d - $src) & ($src - 0x3a)) >> 8) & ($src - 45);
53
 
54
        // if ($src > 0x40 && $src < 0x5b) ret += $src - 0x41 + 12 + 1; // -52
55
        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 52);
56
 
57
        // if ($src > 0x60 && $src < 0x7b) ret += $src - 0x61 + 38 + 1; // -58
58
        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 58);
59
 
60
        return $ret;
61
    }
62
 
63
    /**
64
     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
65
     * into 6-bit integers.
66
     *
67
     * @param int $src
68
     * @return string
69
     */
70
    protected static function encode6Bits(int $src): string
71
    {
72
        $src += 0x2e;
73
 
74
        // if ($src > 0x39) $src += 0x41 - 0x3a; // 7
75
        $src += ((0x39 - $src) >> 8) & 7;
76
 
77
        // if ($src > 0x5a) $src += 0x61 - 0x5b; // 6
78
        $src += ((0x5a - $src) >> 8) & 6;
79
 
80
        return \pack('C', $src);
81
    }
82
}