42 lines
1.1 KiB
PHP
42 lines
1.1 KiB
PHP
<?php
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/**
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* Copyright (c) 2014 Lukas Reschke <lukas@owncloud.com>
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* This file is licensed under the Affero General Public License version 3 or
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* later.
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* See the COPYING-README file.
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*/
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namespace OC\Security;
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class StringUtils {
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/**
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* Compares whether two strings are equal. To prevent guessing of the string
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* length this is done by comparing two hashes against each other and afterwards
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* a comparison of the real string to prevent against the unlikely chance of
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* collisions.
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*
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* Be aware that this function may leak whether the string to compare have a different
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* length.
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*
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* @param string $expected The expected value
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* @param string $input The input to compare against
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* @return bool True if the two strings are equal, otherwise false.
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*/
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public static function equals($expected, $input) {
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if(function_exists('hash_equals')) {
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return hash_equals($expected, $input);
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}
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$randomString = \OC::$server->getSecureRandom()->getLowStrengthGenerator()->generate(10);
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if(hash('sha512', $expected.$randomString) === hash('sha512', $input.$randomString)) {
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if($expected === $input) {
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return true;
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}
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}
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return false;
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}
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} |