Submitted 3 weeks ago by glups@piefed.social to [deleted]
There are two parts to this answer.
First, as many have pointed out, eMudhra as a trusted certificate authority has issued eight high-level certificates with a key length of onle 3-8 bits, when they should be 384 bits long. And yes, the smallest key was ‘4’.
But the other point is tha xkcd predicted using 4 as a random number, decades ago. It was supposed to be a joke.
xkcd also happened to release a comic about a “vulnerability in the number 3” the same day the eMudhra news broke.
Check the alt text on that one :-)
That’s not “happened to”; read the title text if you want to remove all reasonable doubt that it’s a reference to it.
Oh my god, I thought that was a recent meme someone made because of this debacle, didn’t know it was an OG xkcd…
supposed to …
Because it was revealed that an actual TLS certificate used the number 4 as a private key.
Not just a old certificate, A root CA certificate trusted by pretty much everything
because 42 would have been too obvious.
You may find that answr from another community helpful: feddit.online/comment/10016475
That was a really good answer actually
Aw, thanks
An organization trusted with the security of potentially billions of people essentially used the password “4” among other bad choices.
You can read the technical explanation here: emudhra.we-have-a-problem.com
arstechnica.com/…/the-internet-goes-on-high-alert…
It’s hard to properly describe how big a fuckup this is. All I will say is that all the coverage I’ve seen is underselling the potential for harm. There’s nothing you can do except update your shit, pray that everyone in the upstream supply chain of every service you use has updated their shit, and take comfort in the fact that there are no proven wild exploits out there (yet).
Well, even if there’s no update for your shit, it’s still possible to go into the certificate store your browser/OS/whatever uses and delete the compromised certificates.
Not much you can do about everyone else not updating their shit though.
Yeah. The burden is high, though, and it’s outside even most tech-savvy admins’ scope of knowledge.
I mean, I could not tell you off the top of my head how many certificate stores exist on my system and what uses each of them. Is curl safe? Is dnf safe? apt-get? zypper? pip? npm? homebrew? flatpak? Do any of my umpteen Flatpak apps have vulnerable library versions baked in? Do Electron apps bundle their own certificate stores? What about <random bullshit> that has its own built-in autoupdater (less of a problem on Linux than Mac or Windows, but still)?
“Lemmeme” tho. ’twas RIGHT there.
Well … this has taken me down am SSL cryptographic rabbit hole.
TL;DR Because a CA used 4 as a private key in an intermediate certificate.
We live in a simulation xkcd.com/221/
Well, let me tell you. Turns out 4 was a private key.
panda_abyss@lemmy.ca 3 weeks ago
There is a massive security incident this week where an Indian certificate authority used 4 as the private key they used to sign encrypted internet traffic with.
Knowing their secret key lets anyone forge certificates that they can use to snoop on or modify internet traffic.
All 8 of their private keys were under 255, so could be trivially guessed. These certificates were accepted by all major browsers and operating systems, as well as many programming languages and tools.
Rhynoplaz@lemmy.world 3 weeks ago
But, since nobody would expect an organization like that to have a one digit key, wouldn’t that make it extremely hard to guess?
Half kidding here.
StabbingSky@lemmy.zip 3 weeks ago
Not if you’re brute forcing it.
scytale@piefed.zip 3 weeks ago
Security by obscurity is what it’s called in the industry, and yeah it’s not a good way to do it. Automation and scripts would make it trivial to guess.
theneverfox@pawb.social 3 weeks ago
It’s kinda like locking your door by putting a wedge in the crack. Probably, no one is going to try to open your door anyways, and probably, even if they did no one is going to take 5 seconds to examine the door and figure it out
But if someone does, it’s laughably easy to figure it out
balsoft@lemmy.ml 3 weeks ago
Well, someone did guess it so it’s not that hard. The entropy was really low.
Indigobunting@lemmy.world 3 weeks ago
Nit: That that key doesn’t technically encrypt traffic, if I understand correctly. It’s used to verify the identify of a website. So someone with this private key can’t directly read internet traffic. They can set up a man-in-the-middle attack, but they’d also have to compromise DNS to pull it off.
invertedspear@lemmy.zip 2 weeks ago
It’s a little more complex than that. But if you want to encrypt, and you do want your site traffic encrypted, you use site certificate to give the client browser proof that you are who you say you are. You do this by establishing a chain of trust: “I got this proof that I am who I say I am from this major trusted certificate authority” you trust them and they trust me, so we’re all good. You’ve probably seen the warning that a site isn’t secure, and that’s because they let their certificate of trust expire.
This low entropy key means it’s trivial for me to fake that I have that major authority’s trust. The browser needs to be updated to no longer trust that authority. Until it does I can easily fake being anyone and say that compromised site vouches for me. I don’t even need to be a man in the middle, I just need to set up a way that your browser sends you to my fake server instead of the real one. Lots of ways to do that.
panda_abyss@lemmy.ca 3 weeks ago
Yes, I think you’re correct
reksas@sopuli.xyz 3 weeks ago
I just dont understand why they would do this? Putting so shitty key is like they wanted to make it as insecure as possible. Even if the ones responsible were criminally stupid, they still should have understood that this is like leaving the whole thing unlocked.
And for such critical thing. Imagine if this wasnt discovered like this but instead by some competent malicious actor that had resources to coordinate some large scale attack and kept it hidden until just the right moment when they can strike at everything.
I also dont understand how little outrage there even is about this, we were really close to huge catastrophe. Or maybe i have misunderstood the severity of what happened.
Kazumara@discuss.tchncs.de 3 weeks ago
They are saying there were mistakes made with their key generation scripts:
Source: bugzilla.mozilla.org/show_bug.cgi?id=2083449#c11
Personally I’m still a little confused why it makes any difference that the keys were intended for export to their European and US operations