Thanks for sharing this proposal, Georg. I think it's a really good approach for simplifying the UI. I definitely agree it would be good to hide the NoScript toolbar button, and of course we would need to re-surface some of its functionality so it's easier to understand. I want to mention a couple of issues I think we discussed in Montreal but I think might be useful in the discussion here.
1. A current problem we have with NoScript is that it does not respect first-party isolation (FPI), which is both a security and privacy issue. For example, if I set the Security Settings to Medium, and visit youtube.com, and click on the NoScript button to unblock media from YouTube.com, then embedded YouTube videos are now unblocked on all other websites. The same goes for more subtle things like Google Analytics scripts. So I'd propose we try to get FPI working for NoScript unblocking, similar to our enforcement of FPI for Permissions from #21569. That's especially important if we emphasize that controls in the URL bar or the Permissions door-hanger are intended for per-site use.
2. The Security Slider is also quite dangerous if used for per-site purposes. If a user decides they want to visit A.com at "Low" Security and B.com at "High" Security, they have to be very careful not to accidentally expose B.com to "Low" Security. A simple click of the back button could result in a mistake. Or, if the user has multiple tabs or windows open, and they switch the Security Slider, because of the current tab, they apply the new security setting to all open tabs, which could result in accidental unwanted exposure to dangerous content in background tabs.
Therefore, I'm wondering if putting the Security Slider on the toolbar might actually increase the danger for some users by encouraging its frequent use. A possibly safer approach could be to display the global Security Slider either embedded in the about:tor page, or in a prompt at startup. That way we can force users to make a one-time decision for the global setting and discourage them from changing it repeatedly while they browse.
Yet another approach could be to invoke "New Identity" whenever Security Settings are changed, such that all tabs are closed and a new empty window is opened before the new global setting takes effect. (Of course users would need to be warned and given the option to cancel.)
3. I don't think it's feasible to make scripts, Fonts, MathML, some audio, etc., click-to-play. And while it's true that video, SVG and WebGL can be click-to-play, in practice it may be challenging to make the click-to-play behavior work smoothly given the interactions with scripts. So one issue we'll have to consider is how many different per-site options we expose to users in the Permissions doorhanger. I think it would be confusing to ask users to decide which content features (scripts vs. fonts vs videos vs ...) are safe to enable; rather, they should be answering the question: do I consider this website to be dangerous or not? So, my suggestion would be to expose a single toggle option: namely, [all-features-disabled | all-features-enabled].
On Thu, Feb 1, 2018 at 12:27 AM, Georg Koppen gk@torproject.org wrote:
Hi!
I managed to come up with a proposal for redesigning the security controls (see below). As always feedback and discussion is very welcome.
Filename: XXX-redesign-security-controls.txt Title: Redesign of Tor Browser's Security Controls Author: Georg Koppen Created: 1-February-2018 Status: Open
1 Introduction
Tor Browser is well-known for its defenses against web tracking and fingerprinting. However, providing Tor users just a privacy-enhanced browser is often not enough to safeguard against deanonymization attacks as those protections might simply get bypassed by exploiting browser vulnerabilities. Tor Bowser therefore offers several security enhancements as well to reduce that risk. Most of those features are provided by extensions which Tor Browser includes, namely Torbutton, NoScript, and HTTPS Everywhere.
1.1 Motivation
By default Torbutton, NoScript, and HTTPS Everywhere are visible on the toolbar in Tor Browser and there is no hint about possible security enhancements, with the exception of a notification bar shown on first start and pointing to our security slider. This has a number of suboptimal outcomes which this proposal seeks to address:
a) Security controls are scattered over and within different extensions. That makes it hard to understand which knobs a user could turn to improve their security settings while not being exposed to additional fingerprinting risks. b) The toolbar gets cluttered with three additional icons that provide access to both per-site and global security settings. This is confusing to users. Part of the confusion stems from mixing non-global with global security controls on the toolbar not indicating which of them just affect a particular website while others affect the whole browser session. Another part is that users feel the need to navigate through different levels of extension menus to make basic adjustments to their security level. c) There is the security vs. usability trade-off and little incentives to change the default which comes with Tor Browser. That results in users just staying on the lowest security level while at least some of them could get convinced to raise that level if we managed to provide an improved experience around our security controls, both functionality- and UX-wise.
1.2 The State of the Security Controls
That is how the toolbar in Tor Browser looks like currently:
| --- --- ------------------------- --------------- --- --- | | |N| |T| | URL bar | | Search bar | |H| |M| | | --- --- ------------------------- --------------- --- --- |
N = NoScript button T = Torbutton button H = HTTPS Everywhere button M = (Hamburger) Menu button
We include HTTPS Everywhere to help against potential Tor Exit node eavesdroppers and active attackers. To provide users with optional defense-in-depth against JavaScript and other potential exploit vectors, we use NoScript modifying some of its defaults[1]. Torbutton includes the security slider which is meant to give users an easy way to adjust their security level from Standard to Safest, depending on their perceived needs.
2 Proposal
Generally, items on the toolbar serve two important purposes: they are shortcuts to features often used and they inform about current state. With that in mind we can think about redoing our toolbar helping that way with issues outlined in 1.1 a) and b). The remaining problems (part of 1.1 b) and 1.1 c)) will be addressed in section 2.2 and 3.3.
2.1 Restructuring the Toolbar
2.1.1 Removing HTTPS Everywhere and NoScript from the Toolbar
I'd propose we remove both NoScript and HTTPS Everywhere from the toolbar and leave Torbutton on it for now:
Torbutton serves a number of purposes and access to security settings is just one of them. Moreover, we are in the process of restructuring at least part of its functionality right now[2] and more will likely happen in the future in this area. We can think about whether Torbutton should remain on the toolbar after that transition is done.
HTTPS Everywhere has the option to block all unencrypted requests and apart from that is just enforcing HTTPS connections according to the rulesets it ships, which is our default. There is not much gain security-wise leaving it on the toolbar and users might just be confused by the "Block all unencrypted requests" option. I'd argue as well that the status indicator is not important enough to justify precious space on the toolbar either.
NoScript comes with a myriad of configuration options. We try to abstract that away by shipping a list of defaults for Tor Browser[1]. But still having NoScript easily accessible makes it dangerous to choose the wrong option, especially as the majority of its functionality does not need to be exposed for Tor Browser users. Moreover, the scary warning icon which is visible when NoScript allows JavaScript is highly confusing to users as we ship this configuration as our default. Removing the icon from the toolbar should solve those two problems. We might want to think about exposing the small amount of functionality which especially users with the security slider set to "Safest" might need: managing finer-grained script control. See section 2.2 for that.
2.1.2 Adding a Security Settings Button to the Toolbar
I'd like to propose a new button on the toolbar giving easy access to what is essentially the tool that we want to promote: the security slider. We could use an icon similar to the one suggested by ninavizz[3] or come up with a different solution. The button would open the security slider menu with a right-click. With a left-click, keyboard shortcuts, and mouse-wheel scrolling one can adjust the security level directly.
The new toolbar would look like:
| --- --- ------------------------------- --------------- --- | | |T| |S| | URL bar | | Search bar | |M| | | --- --- ------------------------------- --------------- --- |
T = Torbutton button S = Security Settings button M = (Hamburger) Menu button
Note: The reorganized toolbar has the additional benefit that no per-site state is shown anymore on it, which should lead to less confusion about whether the settings visible there apply globally or not.
2.2 Dealing with Per-Site Security Settings
There are a number of features disabled on higher security settings as they are potentially dangerous, yet sometimes users need or want to allow them anyway. So far, these options were exposed by click-to-play buttons or directly in the NoScript user interface accessible over the toolbar button.
With NoScript gone from the toolbar the click-to-play options remain, but easily allowing JavaScript per site and making the status of NoScript related settings visible is not available anymore. To solve this I'd propose to follow the path we are currently taking with our circuit display redesign[2]: we are moving site specific settings into the URL bar. One way to do that would be to use the Permissions section which opens after clicking on the "i" icon in the URL bar. However, while showing the security permissions the user has granted there (too) is a good idea, it does not solve the problem of easily allowing e.g. JavaScript on a website, and seeing its status without the need to click on any button. We could have small icons on the right side of the URL bar accomplishing that, though. That way, users could easily see if they had JavaScript, or WebGL, or ... enabled on that particular website in case they are on higher security levels. Moreover, they would be able to adjust those permissions quickly without the need to deal with any NoScript user interface or additional menus just by toggling those icons. By default only the option to temporarily allow JavaScript would be visible. All the click-to-play features could be made visible once there is a respective object embedded in a website or, even better, once the user actually chose to unblock any of them.
3 Additional Considerations
3.1 Where Are My Extensions Gone?
Some users might be confused and think NoScript and HTTPS Everywhere are gone now, plus they want to have their "old" way of setting their per-site settings back. That's okay and they can easily add NoScript and HTTPS Everywhere back to their toolbar if they wish. It would be good to point this out in the transition phase to the new interface at least.
3.2 How Do We Inform Users about the New Interface?
I don't know yet how we ideally inform users about the new interface. That is not part of this proposal but might merit an own one.
3.3 Should We Change the Default Security Level?
As much as I wished to change the default security level, to e.g. "Safer", right now I think we are not there yet. Part of the security control redesign should be fixing bugs that make the current and new interface less effective and painful to use[4][5][6][7]. We could revisit that discussion, though, once we have solved the low hanging bugs.
[1] https://gitweb.torproject.org/builders/tor-browser-build.git/tree/projects/t... [2] https://trac.torproject.org/projects/tor/ticket/24309 [3] https://trac.torproject.org/projects/tor/ticket/21183 [4] https://trac.torproject.org/projects/tor/ticket/22981 [5] https://trac.torproject.org/projects/tor/ticket/22985 [6] https://trac.torproject.org/projects/tor/ticket/20314 [7] https://trac.torproject.org/projects/tor/ticket/21805
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