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/** \file
* \brief Wrappers for High Resolution Time (Level 2) standard
*
* \see https://w3c.github.io/hr-time/
*
* \author Copyright (C) 2019 Libor Polcak
* \author Copyright (C) 2020 Peter Hornak
*
* \license SPDX-License-Identifier: GPL-3.0-or-later
*/
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//
/** \file
* \ingroup wrappers
*
* This wrapper aims on prevention of microarchitectural attacks, clock-skew attacks, and other time
* related attacks. The goal is to limit the precision of the time returned by the Performance API.
*
* \see https://www.fit.vut.cz/study/thesis/22308/?year=0&sup=Pol%C4%8D%C3%A1k, especially Sect.
* 7.2.
*
* \see Tom Van Goethem, Wouter Joosen, Nick Nikiforakis. The Clock is Still Ticking:
Timing Attacks in the Modern Web. CCS'15. DOI: http://dx.doi.org/10.1145/2810103.2813632.
https://lirias.kuleuven.be/retrieve/389086
*
* \see Schwarz, M., Lipp, M. a Gruss, D. JavaScript Zero: Real JavaScript and Zero
* Side-Channel Attacks. NDSS'18.
*
* \see Schwarz M., Maurice C., Gruss D., Mangard S. (2017) Fantastic Timers and Where to Find Them: High-Resolution Microarchitectural Attacks in JavaScript. In: Kiayias A. (eds) Financial Cryptography and Data Security. FC 2017. Lecture Notes in Computer Science, vol 10322. Springer, Cham. https://doi.org/10.1007/978-3-319-70972-7_13
*
* The wrappers support the following behaviour:
*
* * Round timestamp: Limit the precision by removing (a part of) the decimal part of the timestamp.
* * Randomize after rounding: Create a fake decimal part to confuse attackers and to create
* timestamps that look similar to expected timestamps.
*/
/*
* Create private namespace
*/
(function() {
var wrappers = [
{
parent_object: "Performance.prototype",
parent_object_property: "now",
wrapped_objects: [
{
original_name: "Performance.prototype.now",
wrapped_name: "origNow",
}
],
helping_code: rounding_function + noise_function + `
let precision = args[0];
let doNoise = args[1];
`,
wrapping_function_args: "",
wrapping_function_body: `
var originalPerformanceValue = origNow.call(window.performance);
var limit_precision = doNoise ? noise_function : rounding_function;
return limit_precision(originalPerformanceValue, precision);
`,
},
];
add_wrappers(wrappers);
})();
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