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> ... Y4 does U2F along with the smard card RSA stuff. PIV applet also supports P-256: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html http

by Leace 8y ago

> ... Y4 does U2F along with the smard card RSA stuff. PIV applet also supports P-256: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html https://developers.yubico.com/PIV/Introduction/YubiKey_and_P... > ... for every time I use the smart card RSA stuff (for instance, to SSH into something with a long-term RSA key), I use the U2F feature 10 times. Does that mean you use SSH rarely, login to U2F sites frequently or use different keys for SSH (e.g. not on Yubikey)?

pvg 8y ago
https://news.ycombinator.com/item?id=17682946 https://news.ycombinator.com/item?id=17682946 The thread is actually better than the linked post because it tells you about ways you can (relatively easily) set up systems without long-term ssh keys.
- tptacek 8y ago
  Right, there's an interesting split in modernizing/hardening SSH philosophies: Philosophy 1: Move to hardware SSH keys. That's what Y4s and Nitrokeys represent: keys where, if your machine is compromised, the SSH key itself can't easily be stolen. Philosophy 2: Move to SSH CAs that issue short-lived certificates, and use U2F to authenticate issuance. This is roughly how you'd do a modern integration of an SSO system (like Okta or GSuite) with your SSH services. SSH CAs have more steam behind them, and are desirable for a bunch of reasons that hardware SSH keys don't really address. Since the primary function (beyond U2F, which these keys don't do) of a hardware key is to protect your SSH key, I guess it's worth considering how they fit into the modern SSH worldview or whatever you want to call it.
  - nickik 8y ago
    I like non of these optins. What I want is U2F for every ssh connection.
    - zimbatm 8y ago
      HashiCorp Vault also supports that scenario: https://github.com/hashicorp/vault-ssh-helper https://github.com/hashicorp/vault-ssh-helper . The main downside is that if the Vault instance is down, nothing can be SSHed into.
  - Leace 8y ago
    Isn't using U2F+SSH CA's just moving the challenge-response protocol one level up? U2F is "just" a hardware P-256 key (or a set of keys unique to origin, but ignoring privacy issues they are comparable, of course I'm assuming the same setup so touch-to-use set to required). (I've set up SSH CAs manually and I'm familiar with low level U2F for that matter).

by Leace 8y ago

pvg 8y ago

https://news.ycombinator.com/item?id=17682946 https://news.ycombinator.com/item?id=17682946 The thread is actually better than the linked post because it tells you about ways you can (relatively easily) set up systems without long-term ssh keys.

tptacek 8y ago
Right, there's an interesting split in modernizing/hardening SSH philosophies: Philosophy 1: Move to hardware SSH keys. That's what Y4s and Nitrokeys represent: keys where, if your machine is compromised, the SSH key itself can't easily be stolen. Philosophy 2: Move to SSH CAs that issue short-lived certificates, and use U2F to authenticate issuance. This is roughly how you'd do a modern integration of an SSO system (like Okta or GSuite) with your SSH services. SSH CAs have more steam behind them, and are desirable for a bunch of reasons that hardware SSH keys don't really address. Since the primary function (beyond U2F, which these keys don't do) of a hardware key is to protect your SSH key, I guess it's worth considering how they fit into the modern SSH worldview or whatever you want to call it.
- nickik 8y ago
  I like non of these optins. What I want is U2F for every ssh connection.
  - zimbatm 8y ago
    HashiCorp Vault also supports that scenario: https://github.com/hashicorp/vault-ssh-helper https://github.com/hashicorp/vault-ssh-helper . The main downside is that if the Vault instance is down, nothing can be SSHed into.
- Leace 8y ago
  Isn't using U2F+SSH CA's just moving the challenge-response protocol one level up? U2F is "just" a hardware P-256 key (or a set of keys unique to origin, but ignoring privacy issues they are comparable, of course I'm assuming the same setup so touch-to-use set to required). (I've set up SSH CAs manually and I'm familiar with low level U2F for that matter).