cultural reviewer and dabbler in stylistic premonitions

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Joined 3 years ago
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Cake day: January 17th, 2022

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  • TLDR: this is way more broken than I initially realized

    To clarify a few things:

    -No JavaScript is sent after the file metadata is submitted

    So, when i wrote “downloaders send the filename to the server prior to the server sending them the javascript” in my first comment, I hadn’t looked closely enough - I had just uploaded a file and saw that the download link included the filename in the query part of the URL (the part between the ? and the #). This is the first thing that a user sends when downloading, before the server serves the javascript, so, the server clearly can decide to serve malicious javascript or not based on the filename (as well as the user’s IP).

    However, looking again now, I see it is actually much worse - you are sending the password in the URL query too! So, there is no need to ever serve malicious javascript because currently the password is always being sent to the server.

    As I said before, the way other similar sites do this is by including the key in the URL fragment which is not sent to the server (unless the javascript decides to send it). I stopped reading when I saw the filename was sent to the server and didn’t realize you were actually including the password as a query parameter too!

    😱

    The rest of this reply was written when I was under the mistaken assumption that the user needed to type in the password.


    That’s a fundamental limitation of browser-delivered JavaScript, and I fully acknowledge it.

    Do you acknowledge it anywhere other than in your reply to me here?

    This post encouraging people to rely on your service says “That means even I, the creator, can’t decrypt or access the files.” To acknowledge the limitations of browser-based e2ee I think you would actually need to say something like “That means even I, the creator, can’t decrypt or access the files (unless I serve a modified version of the code to some users sometimes, which I technically could very easily do and it is extremely unlikely that it would ever be detected because there is no mechanism in browsers to ensure that the javascript people are running is always the same code that auditors could/would ever audit).”

    The text on your website also does not acknowledge the flawed paradigm in any way.

    This page says "Even if someone compromised the server, they’d find only encrypted files with no keys attached — which makes the data unreadable and meaningless to attackers. To acknowledge the problem here this sentence would need to say approximately the same as what I posted above, except replacing “unless I serve” with “unless the person who compromised it serves”. That page goes on to say that “Journalists and whistleblowers sharing sensitive information securely” are among the people who this service is intended for.

    The server still being able to serve malicious JS is a valid and well-known concern.

    Do you think it is actually well understood by most people who would consider relying on the confidentiality provided by your service?

    Again, I’m sorry to be discouraging here, but: I think you should drastically re-frame what you’re offering to inform people that it is best-effort and the confidentiality provided is not actually something to be relied upon alone. The front page currently says it offers “End-to-end encryption for complete security”. If someone wants/needs to encrypt files so that a website operator cannot see the contents, then doing so using software ephemerally delivered from that same website is not sufficient: they should encrypt the file first using a non-web-based tool.

    update: actually you should take the site down, at least until you make it stop sending the key to the server.


  • Btw, DeadDrop was the original name of Aaron Swartz’ software which later became SecureDrop.

    it’s zero-knowledge encryption. That means even I, the creator, can’t decrypt or access the files.

    I’m sorry to say… this is not quite true. You (or your web host, or a MITM adversary in possession of certificate authority key) can replace the source code at any time - and can do so on a per-user basis, targeting specific IP addresses - to make it exfiltrate the secret key from the uploader or downloader.

    Anyone can audit the code you’ve published, but it is very difficult to be sure that the code one has audited is the same as the code that is being run each time one is using someone else’s website.

    This website has a rather harsh description of the problem: https://www.devever.net/~hl/webcrypto … which concludes that all web-based cryptography like this is fundamentally snake oil.

    Aside from the entire paradigm of doing end-to-end encryption using javascript that is re-delivered by a webserver at each use being fundamentally flawed, there are a few other problems with your design:

    • allowing users to choose a password and using it as the key means that most users’ keys can be easily brute-forced. (Since users need to copy+paste a URL anyway, it would make more sense to require them to transmit a high-entropy key along with it.)
    • the filenames are visible to the server
    • downloaders send the filename to the server prior to the server sending them the javascript which prompts for the password and decrypts the file. this means you have the ability to target maliciously modified versions of the javascript not only by IP but also by filename.

    There are many similar browser-based things which still have the problem of being browser-based but which do not have these three problems: they store the file under a random identifier (or a hash of the ciphertext), and include a high-entropy key in the “fragment” part of the URL (the part after the # symbol) which is by default not sent to the server but is readable by the javascript. (Note that the javascript still can send the fragment to the server, however… it’s just that by default the browser does not.)

    I hope this assessment is not too discouraging, and I wish you well on your programming journey!















  • Arthur Besse@lemmy.mltoOpen Source@lemmy.mlEU OS
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    2 months ago

    As I wrote in the thread about this last month on !linux@lemmy.ml:

    I wonder how much work is entailed in transforming Fedora in to a distro that meets some definition of the word “Sovereign” 🤔

    Personally I wouldn’t want to make a project like this be dependent on the whims of a US defense contractor like RedHat/IBM, especially after what happened with CentOS.

    and, re: “what do you mean ‘redhat is a defense contractor’?!”: here are some links.

    screenshot of RedHat PDF saying: Compress the kill cycle with Red Hat Device Edge.
Deploy on any aircraft, pod,
sensor, or C2 node
 Ability to comply with
cybersecurity requirements
Executive summary
The U.S. Air Force and its mission partners are fielding new mission capabilities on airframes and
command-and-control (C2) nodes to compress the kill chain. The find, fix, track, target, engage,
assess (F2T2EA) process requires ubiquitous access to data at the strategic, operational and tactical
levels. Red Hat® Device Edge embeds captured, analyzed, and federated data sets in a manner that
positions the warfighter to use artificial intelligence and machine learning (AI/ML) to increase the
accuracy of airborne targeting and mission-guidance systems. Challenges of edge computing on
aircraft and other tactical C2 edge nodes include delivering consistent capabilities on diverse
hardware (new and old, connected and disconnected), meeting airworthiness security requirements,
and efficiently sustaining software at scale. The Air Force can meet these requirements with
Red Hat Device Edge, the edge-optimized software platform that is hardware agnostic.
Opportunity: Use edge technology to defeat the adversary
The Air Force and its partners are developing innovative capabilities on airborne and ground systems
to gain battlespace advantage, including:
 Coalescing and stratifying data to feed AI/ML at the edge to increase the accuracy of
targeting and mission-guidance systems and compresses the mean time to detect (MTTD),
make sense and act across all warfighter domains.
 Delivering near real-time data from sensor pods directly to airmen, accelerating the
sensor-to-shooter cycle.
 Supporting Agile Combat Employment (ACE) in the highly contested
21st-century battlespace.
 Sharing near real-time sensor fusion data with joint and multinational forces to increase
awareness, survivability, and lethality.
“With Red Hat Device
Edge Lockheed Martin
is leading the infusion
of cutting-edge
commercial technology
into military capabilities
that deliver advanced
solutions to our
customers. Unlocking
these AI technologies
can help national
security decision
makers stay ahead of
adversaries, enabling
a safer and more
secure world.”
Justin Taylor
Vice President, F-22 technology,
Lockheed Martin 1
1 Red Hat press release. “Lockheed Martin, Red Hat Collaborate to Advance Artificial Intelligence for Military Missions,”
25 Oct. 2022.

    (source)


















  • I often see Rust mentioned at the same time as MIT-type licenses. Is it just a cultural thing that people who write Rust dislike Libre licenses?

    The word “libre” in the context of licensing exists to clarify the ambiguity of the word “free”, to emphasize that it means “free as in freedom” rather than “free as in beer” (aka no cost, or gratis) as the FSF explains here.

    The MIT license is a “libre” license, because it does meet the Free Software Definition.

    I think the word you are looking for here is copyleft: the MIT license is a permissive license, meaning it is not a copyleft license.

    I don’t know enough about the Rust community to say why, but from a distance my impression is that yes they do appear to have a cultural preference for permissive licenses.