2

I'm on macos with a Yubikey. The Yubikey's publickey is added to ServerA and ServerB. I can connect to any server directly from macos with the Yubikey plugged in.

Is it possible to SSH to ServerA and from there to ServerB like so:

macos -> ServerA -> ServerB

This does not work out of the box because the publikey of user@ServerA is not known on ServerB.

Is it possible to have ServerA use the Yubikey that is plugged into the mac when connecting to ServerB via SSH?

  • I don't understand the bit about the public key not being known but it sounds like you're looking for man ssh, particularly the -J option. – Ginnungagap Sep 7 '18 at 20:53
1

You have a couple options:

  1. Agent forwarding (-A)

    $ ssh -A ServerA
    [ServerA] $ ssh ServerB
    
  2. ProxyJump (-J)

    $ ssh -J ServerA ServerB
    

I've used both of these with gpg-agent and Yubikey.

| improve this answer | |
  • I vote for the ProxyJump option. It's simpler (especially if you put it in ~/.ssh/config on the client), works transparently with scp and sftp, and doesn't expose anything other than encrypted connection on ServerA (just in case that's been exploited somehow). – Gordon Davisson Sep 8 '18 at 11:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.