3 ms·

I’ve always used this: https://www.sshaudit.com/hardening_guides.html https://www.sshaudit.com/hardening_guides.html If there’s something better please correct

I’ve always used this: https://www.sshaudit.com/hardening_guides.html https://www.sshaudit.com/hardening_guides.html If there’s something better please correct me!

akulbe 4y ago
I wasn't familiar with this. I find it interesting that one of the suggestions is to disable the ECDSA host key. I thought ECDSA was one of the "good" algorithms?
- EnigmaCurry 4y ago
  Its suspected from the snowden docs that this is one of the ones intentionally weakened by NIST. Here's the long answer: https://blog.cr.yp.to/20140323-ecdsa.html https://blog.cr.yp.to/20140323-ecdsa.html
  - tptacek 4y ago
    Nobody serious thinks the P-curves, which is what we're talking about, were weakened by NIST. I don't think anybody at all thinks the DSA algorithm was "intentionally weakened", but lots of people, reasonably, believe it was incompetently designed. Ed2519 has the virtue of both a better curve and a better signing algorithm, which is why it's used in preference to ECDSA. If you're using 25519, don't bother keeping the rest of the algorithms enabled. I think these hardening guides are mostly pretty silly too, for whatever that's worth. The important thing is making sure nobody can log into anything with a password. The rest is just liturgical.
- youainti 4y ago
  I think it is the issue where ecdsa is a NIST standard that was based on an elliptic curve provided by the NSA. As the NSA has been known to suggest poor cryptography primitives in the past, many groups recommend ed25519 (same process, different and more trusted curve generation process) Take a look at the "concerns" section of the wiki page. https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm?wprov=sfla1 https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signatu...
pferde 4y ago
Wow, that's terrible. Imperative instead of declarative, and does not explain the reasons. Perfect for cargo-culting your way to disaster.
- amelius 4y ago
  Also, why isn't hardened ssh the default? Is this breaking too many things for the user?
  - antihero 4y ago
    Compatibility basically.
- antihero 4y ago
  Would you recommend a better guide? Is the config suggested by it bad? Not everyone has the skill/time to deeply understand everything immediately, and having a saner starting point is a good thing.

I’ve always used this: https://www.sshaudit.com/hardening_guides.html https://www.sshaudit.com/hardening_guides.html If there’s something better please correct me!

akulbe 4y ago

I wasn't familiar with this. I find it interesting that one of the suggestions is to disable the ECDSA host key. I thought ECDSA was one of the "good" algorithms?

EnigmaCurry 4y ago
Its suspected from the snowden docs that this is one of the ones intentionally weakened by NIST. Here's the long answer: https://blog.cr.yp.to/20140323-ecdsa.html https://blog.cr.yp.to/20140323-ecdsa.html
- tptacek 4y ago
  Nobody serious thinks the P-curves, which is what we're talking about, were weakened by NIST. I don't think anybody at all thinks the DSA algorithm was "intentionally weakened", but lots of people, reasonably, believe it was incompetently designed. Ed2519 has the virtue of both a better curve and a better signing algorithm, which is why it's used in preference to ECDSA. If you're using 25519, don't bother keeping the rest of the algorithms enabled. I think these hardening guides are mostly pretty silly too, for whatever that's worth. The important thing is making sure nobody can log into anything with a password. The rest is just liturgical.
youainti 4y ago
I think it is the issue where ecdsa is a NIST standard that was based on an elliptic curve provided by the NSA. As the NSA has been known to suggest poor cryptography primitives in the past, many groups recommend ed25519 (same process, different and more trusted curve generation process) Take a look at the "concerns" section of the wiki page. https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm?wprov=sfla1 https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signatu...

pferde 4y ago

Wow, that's terrible. Imperative instead of declarative, and does not explain the reasons. Perfect for cargo-culting your way to disaster.

amelius 4y ago
Also, why isn't hardened ssh the default? Is this breaking too many things for the user?
- antihero 4y ago
  Compatibility basically.
antihero 4y ago
Would you recommend a better guide? Is the config suggested by it bad? Not everyone has the skill/time to deeply understand everything immediately, and having a saner starting point is a good thing.