It was at the Securedrop website. How did I end up there ? I read something about Sequoia and encryption and then wanted to see what Securedrop entailed.

Meanwhile I’ve raised the security settings. Still, today someone in this community (?) mentioned that Tor browser does not protect the remote to check for the OS, and now this. Color me surprised.

  • lemmyreaderOPEnglish
    14•2 months ago

    Thanks for the heads up. Yes, I tried CreepJS before and saw it found Linux as a result :/

    • Redjard
      7•2 months ago

      That can’t have been the reason, rather the fact it could tell.
      Your browser sends information about its version and the os in the useragent string. It is supposed to lie and say it is a very commonly used useragent, specifically for purposes of fingerprinting. That would be windows, default configuration, firefox version something not you firefox version

        • Redjard
          9•2 months ago

          That would be a fail of the fingerprinting protection. A properly set up TOR browser for example should not allow that detection by any means. If you know how to detect it, please report it as a critical vulnerability.

          I could think of maybe some edge case behavior in webrenderer or js cavas etc., which would mainly expose info on the specific browser and underlying hardware, but that is all of course blocked of or fixed in hardened browsers.

          Further, if you have a reliable method, you could sell it off to for example Netflix, who are trying to block higher resolutions for Linux browsers but are currently foiled by changing the useragent (if you have widevine set up).

          • @Deckweiss@lemmy.world
            3•2 months ago

            What do you mean by “properly configured”

            Here is a screenshot of the default Tor Browser, installed from the repos, no config changes made. As you can see, creepjs can detect that I am using Linux.

            Obviously, if you disable js, then the site doesn’t work. Not sure if there are ways to detect the OS without javascript.

            One common way to analyze the OS if all else fails is to look which fonts are installed. This is done by rendering thousands of divs with some text out of sight of the user. Each div with a different font. If the div width changes compared to the default, you know a font is installed. Different OS have different sets of fonts by default. Not sure if flatpak/flatseal (or other containerization methods) could protect against that. Technically you can install the exact set of Windows fonts and uninstall all Linux fonts, but I’d expect some linux app breakage and general uglyness.

            An online search I did for how to completely hide the OS without breaking most websites did not result in anything except runnjng the browser in a Windows VM.

            EDIT:

            Per default tor has a linux useragent. And I can’t seem to change it with the useragent switcher or with about config override. So yeah… even better.

            • Redjard
              2•2 months ago

              Default linux works too ofc, I didn’t know they took that route.
              Most other browsers have very specific useragents, so the main pool of same useragents will be hardened browsers anyway.

              Thank you for checking

              edit:
              https://github.com/TheTorProject/tor-messenger-build/blob/581ba7d2f5f9c22d9c9182a45c12bcf8c1f57e6e/projects/instantbird/0001-Set-Tor-Messenger-preferences.patch#L354 would indicate it should be Windows, Ill check later.
              Try it with high security settings in tor, it might be something like canvas. Did you enable any permissions for the website?

            • lemmyreaderOPEnglish
              2•2 months ago

              Per default tor has a linux useragent. And I can’t seem to change it with the useragent switcher or with about config override. So yeah… even better.

              As far as I know Tor browser defaults to a Windows useragent string since years. Just double-checked by visiting a website I maintain and checked its web-server log files :

              “Mozilla/5.0 (Windows NT 10.0; rv:109.0) Gecko/20100101 Firefox/115.0”

              My results with LibreWolf are the same : also Windows. Plain Firefox shows the correct real OS Linux as useragent string.

    • @delirious_owl
      4•2 months ago

      But if it says Linux when you use windows then it doesn’t matter, right? The point is to make them all look the same

      • lemmyreaderOPEnglish
        9•2 months ago

        Tor browser useragent string pretends to be Windows on all platforms. CreepJS detects Linux in my case. A commenter mentions that Tor browser does not protect OS detection. That gives me mixed feelings about the goals of Tor browser.

        • @Syn_Attck@lemmy.today
          5•2 months ago

          There are many things you can do with JavaScript, and tor can only protect against so many without completely breaking many sites. Set your slider all the way to maximum and it will no longer detect windows, but it will very likely also no longer run.