74 lines
2.5 KiB
JavaScript
74 lines
2.5 KiB
JavaScript
/** \file
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* \brief Main file handling wrappers
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*
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* \author Copyright (C) 2019 Libor Polcak
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*
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* \license SPDX-License-Identifier: GPL-3.0-or-later
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*/
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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//
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/**
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* \defgroup wrappers JavaScript Shield
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*
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* \brief Wrappers are small pieces of code that modifies the original functionalty of a function,
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* or property defined by standards.
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*
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* $(PROJECT_NAME) defines wrappers to modify the behaviour of the JavaScript environment. The
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* purpose of the most of the wrappers can be divided into several categories:
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*
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* * Block APIs: some APIs are not generally needed and can be blocked for most of the pages.
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* * Precision reduction: The returned value is too precise which might result into attacks on the
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* browser or can be used to fingerprint users.
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* * Hide information: Some APIs provide information that is not generally needed and can be hidden
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* from most of the pages.
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* * Provide fake information: We provide fake information mostly to confuse fingerprinters.
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*/
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/**
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* The object carrying all the wrappers
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*/
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var build_wrapping_code = {};
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/**
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* Adds a list of wrapping objects to the build_wrapping_code.
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*
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* This function is called from each wrapper in its file.
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*/
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function add_wrappers(wrappers) {
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for (wrapper of wrappers) {
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build_wrapping_code[wrapper.parent_object + "." + wrapper.parent_object_property] = wrapper;
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}
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}
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/**
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* Function to be used by wrapped code used for rounding
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*/
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var rounding_function = `function rounding_function(numberToRound, precision) {
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return numberToRound - (numberToRound % precision);
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}`;
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/**
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* Function to be used by wrapped code for adding randomized noise
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*/
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var noise_function = `let lastValue = 0;
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function noise_function(numberToChange, precision) {
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const noise = Math.floor(Math.random() * precision);
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var value = numberToChange + noise;
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if (lastValue < value) {
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lastValue = value;
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}
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return lastValue;
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}`;
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