1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/** \file
* \brief Wrappers for High Resolution Time (Level 2) standard
*
* \see https://w3c.github.io/hr-time/
*
* \author Copyright (C) 2025 Libor Polcak
*
* \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 Temporal 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: "Temporal.Now",
parent_object_property: "instant",
wrapped_objects: [
{
original_name: "Temporal.Now.instant",
wrapped_name: "originalTemporalNowInstant",
},
],
helping_code: rounding_function + noise_function +
`
var precision = args[0];
var doNoise = args[1];
var func = rounding_function;
if (doNoise) {
func = noise_function;
}
`,
wrapping_function_args: "",
wrapping_function_body: `
var original = originalTemporalNowInstant();
var originalEpochMilliseconds = original.epochMilliseconds;
var changedValue = func(originalEpochMilliseconds, precision);
var fakeInstant = new Temporal.Instant(BigInt(changedValue) * 1000000n); // Note that we cannot return this value as it may contain different zone and other metadata to the original
var durationUntil = original.until(fakeInstant);
var result = original.add(durationUntil);
return result;
`,
},
]
add_wrappers(wrappers);
})()
|