2 namespace ParagonIE\ConstantTime;
5 * Copyright (c) 2016 Paragon Initiative Enterprises.
6 * Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included in all
16 * copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
28 * Class Base64DotSlash
31 * @package ParagonIE\ConstantTime
33 abstract class Base64UrlSafe extends Base64
37 * Uses bitwise operators instead of table-lookups to turn 6-bit integers
38 * into 8-bit integers.
40 * Base64 character set:
41 * [A-Z] [a-z] [0-9] - _
42 * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2d, 0x5f
47 protected static function decode6Bits($src)
51 // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64
52 $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
54 // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70
55 $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70);
57 // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5
58 $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5);
60 // if ($src == 0x2c) $ret += 62 + 1;
61 $ret += (((0x2c - $src) & ($src - 0x2e)) >> 8) & 63;
63 // if ($src == 0x5f) ret += 63 + 1;
64 $ret += (((0x5e - $src) & ($src - 0x60)) >> 8) & 64;
70 * Uses bitwise operators instead of table-lookups to turn 8-bit integers
71 * into 6-bit integers.
76 protected static function encode6Bits($src)
80 // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6
81 $diff += ((25 - $src) >> 8) & 6;
83 // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75
84 $diff -= ((51 - $src) >> 8) & 75;
86 // if ($src > 61) $diff += 0x2d - 0x30 - 10; // -13
87 $diff -= ((61 - $src) >> 8) & 13;
89 // if ($src > 62) $diff += 0x5f - 0x2b - 1; // 3
90 $diff += ((62 - $src) >> 8) & 49;
92 return \pack('C', $src + $diff);