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
30 * Binary string operators that don't choke on
31 * mbstring.func_overload
33 * @package ParagonIE\ConstantTime
40 * @ref mbstring.func_overload
45 public static function safeStrlen($str)
47 if (\function_exists('mb_strlen')) {
48 return \mb_strlen($str, '8bit');
57 * @ref mbstring.func_overload
59 * @staticvar boolean $exists
66 public static function safeSubstr(
71 if (\function_exists('mb_substr')) {
72 // mb_substr($str, 0, NULL, '8bit') returns an empty string on PHP
73 // 5.3, so we have to find the length ourselves.
74 if ($length === null) {
76 $length = self::safeStrlen($str) - $start;
81 // $length calculation above might result in a 0-length string
85 return \mb_substr($str, $start, $length, '8bit');
90 // Unlike mb_substr(), substr() doesn't accept NULL for length
91 if ($length !== null) {
92 return \substr($str, $start, $length);
94 return \substr($str, $start);