1<?php 2declare(strict_types=1); 3namespace ParagonIE\ConstantTime; 4 5/** 6 * Copyright (c) 2016 - 2018 Paragon Initiative Enterprises. 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 Base64DotSlash 30 * ./[A-Z][a-z][0-9] 31 * 32 * @package ParagonIE\ConstantTime 33 */ 34abstract class Base64DotSlash 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 * ./ [A-Z] [a-z] [0-9] 42 * 0x2e-0x2f, 0x41-0x5a, 0x61-0x7a, 0x30-0x39 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 < 0x30) ret += $src - 0x2e + 1; // -45 52 $ret += (((0x2d - $src) & ($src - 0x30)) >> 8) & ($src - 45); 53 54 // if ($src > 0x40 && $src < 0x5b) ret += $src - 0x41 + 2 + 1; // -62 55 $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 62); 56 57 // if ($src > 0x60 && $src < 0x7b) ret += $src - 0x61 + 28 + 1; // -68 58 $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 68); 59 60 // if ($src > 0x2f && $src < 0x3a) ret += $src - 0x30 + 54 + 1; // 7 61 $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 7); 62 63 return $ret; 64 } 65 66 /** 67 * Uses bitwise operators instead of table-lookups to turn 8-bit integers 68 * into 6-bit integers. 69 * 70 * @param int $src 71 * @return string 72 */ 73 protected static function encode6Bits(int $src): string 74 { 75 $src += 0x2e; 76 77 // if ($src > 0x2f) $src += 0x41 - 0x30; // 17 78 $src += ((0x2f - $src) >> 8) & 17; 79 80 // if ($src > 0x5a) $src += 0x61 - 0x5b; // 6 81 $src += ((0x5a - $src) >> 8) & 6; 82 83 // if ($src > 0x7a) $src += 0x30 - 0x7b; // -75 84 $src -= ((0x7a - $src) >> 8) & 75; 85 86 return \pack('C', $src); 87 } 88} 89