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I think this is a topic worth raising, I spend so much time auditing the "magic" in open source projects to try and find out how they work behind the scenes, an

by mpeg 12y ago

I think this is a topic worth raising, I spend so much time auditing the "magic" in open source projects to try and find out how they work behind the scenes, and whether they are doing anything to protect me. For example: Pip (python package manager) tells you to run a "secure" script off the internet [0], where the only real protection is being behind SSL. But, surely I can just check the code of that script? Oh wait, it's embedding a zip file inside the python script, so I need to manually unzip it and look into it before I can start to consider it safe. I like what CoreOS does, they don't even provide SSL download links for their isos, it's all plain text http, so they stress that you need to verify the image signature against their GPG signing key which is distributed via github. [0] https://bootstrap.pypa.io/get-pip.py https://bootstrap.pypa.io/get-pip.py

_prometheus 12y ago
> I like what CoreOS does, they don't even provide SSL download links for their isos, it's all plain text http, so they stress that you need to verify the image signature against their GPG signing key which is distributed via github. Sounds very much like TRTTD. I'll see about this with `sigpipe` (hashpipe with signatures). The fundamental problem is PKI is weak. using github isn't great either. We need a chain of trust that's sane (CA system is not sane).
- digi_owl 12y ago
  What is "sane" when you are potentially up against attackers that may have clusters to brute force collision with?
hueving 12y ago
>so they stress that you need to verify the image signature against their GPG signing key which is distributed via github. If someone has the ability to MiTM HTTPS connections, they could just as easily MiTM the victim's connection to github to return a different GPG signing key. Also, the protection requires active checking rather than coming 'for free' like it does by downloading via HTTPS, so 95%+ of the users won't bother and won't have any protection. I think CoreOS took a big step backwards here. Just offer the download links via HTTPS in addition to the GPG key. That way people that don't bother with GPG have protection.
- deleted 12y ago
  [deleted]
- e12e 12y ago
  If you use CoreOS, you just need to get the Core OS key one time, and sign it with your own key, then let the keyservers mirror it for you. An adversary can still make sure you can't connect to any key servers -- but it's an order of magnitude easier to verify a single GPG key (even if that involves getting on a plane and talking to a CoreOS developer in person) -- than it is to verify every single CA cert shipped with your browser. Just look at the latest CNNIC key removal: essentially Google and Firefox are saying that SSL was never secure, because we couldn't trust CNNIC, even though everyone shipped their keys. Before that, no browser was secure, because a number of CAs were compromised, and or incompetent. While GPG isn't some magic dust that makes trust easy -- it's crazy to claim that SSL is somehow more secure, or more importantly, easier to trust. [edit: And that doesn't even touch on the number of lines of code involved, the directness of the path between what is signed, and who will use it (security of the web server, dns etc not an issue if you know you can trust the GPG signature...]
- mpeg 12y ago
  SSL does nothing to guarantee the integrity of code you download and run off the internet. I'm not worried about MITM attacks, SSL provides adequate protection against those in most cases; but if someone gains access to the coreos systems SSL would not help. In this case, I have a GPG key saved for the coreos image signing, which hopefully is done offline and I got that through a third party which I have a certain amount of trust on (github), and I can always verify it on other channels.
  - hueving 12y ago
    But did you verify it on other channels? Or did you do like 99.9% of users and assume nobody would be attacking you? My point is mainly that gpg is such a usability nightmare that it's effectively a broken security model.

by mpeg 12y ago

_prometheus 12y ago

> I like what CoreOS does, they don't even provide SSL download links for their isos, it's all plain text http, so they stress that you need to verify the image signature against their GPG signing key which is distributed via github. Sounds very much like TRTTD. I'll see about this with `sigpipe` (hashpipe with signatures). The fundamental problem is PKI is weak. using github isn't great either. We need a chain of trust that's sane (CA system is not sane).

digi_owl 12y ago
What is "sane" when you are potentially up against attackers that may have clusters to brute force collision with?

hueving 12y ago

>so they stress that you need to verify the image signature against their GPG signing key which is distributed via github. If someone has the ability to MiTM HTTPS connections, they could just as easily MiTM the victim's connection to github to return a different GPG signing key. Also, the protection requires active checking rather than coming 'for free' like it does by downloading via HTTPS, so 95%+ of the users won't bother and won't have any protection. I think CoreOS took a big step backwards here. Just offer the download links via HTTPS in addition to the GPG key. That way people that don't bother with GPG have protection.

deleted 12y ago
[deleted]
e12e 12y ago
If you use CoreOS, you just need to get the Core OS key one time, and sign it with your own key, then let the keyservers mirror it for you. An adversary can still make sure you can't connect to any key servers -- but it's an order of magnitude easier to verify a single GPG key (even if that involves getting on a plane and talking to a CoreOS developer in person) -- than it is to verify every single CA cert shipped with your browser. Just look at the latest CNNIC key removal: essentially Google and Firefox are saying that SSL was never secure, because we couldn't trust CNNIC, even though everyone shipped their keys. Before that, no browser was secure, because a number of CAs were compromised, and or incompetent. While GPG isn't some magic dust that makes trust easy -- it's crazy to claim that SSL is somehow more secure, or more importantly, easier to trust. [edit: And that doesn't even touch on the number of lines of code involved, the directness of the path between what is signed, and who will use it (security of the web server, dns etc not an issue if you know you can trust the GPG signature...]
mpeg 12y ago
SSL does nothing to guarantee the integrity of code you download and run off the internet. I'm not worried about MITM attacks, SSL provides adequate protection against those in most cases; but if someone gains access to the coreos systems SSL would not help. In this case, I have a GPG key saved for the coreos image signing, which hopefully is done offline and I got that through a third party which I have a certain amount of trust on (github), and I can always verify it on other channels.
- hueving 12y ago
  But did you verify it on other channels? Or did you do like 99.9% of users and assume nobody would be attacking you? My point is mainly that gpg is such a usability nightmare that it's effectively a broken security model.