Refine public key usage when remote

[jwhonce]

• Move all public key handling into one AuthMethod
• Cache server connection when tunneling, saves one RoundTrip on ssh
  handshake
• --log-level=debug now prints the fingerprints of all keys that will be presented to the server

Signed-off-by: Jhon Honce [email protected]

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jwhonce

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [jwhonce]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[jwhonce]

@ashley-cui Do you want to see how this works for you? I still have the issue where sshd allows the ssh command to use RSA keys but denies the golang agent. Tweaking the connection creation should help with the login prompting.

[rhatdan]

@containers/podman-maintainers PTAL
@ashley-cui PTAL

[ashley-cui]

I'm still running into the the key passphrase prompt when there is an identity file containers.conf. It looks like its going through the dedup though

DEBU[0002] SSH Ident Key "/Users/ashley/.ssh/pdmnpass" SHA256:XSN/741107mJBUr1OLiUEGZTBlB2pMdGceTgwITDlvU ssh-ed25519 
DEBU[0002] Found SSH_AUTH_SOCK "/private/tmp/com.apple.launchd.boLD2kVfAw/Listeners", ssh-agent signer(s) enabled 
DEBU[0002] SSH Agent Key SHA256:XSN/741107mJBUr1OLiUEGZTBlB2pMdGceTgwITDlvU ssh-ed25519 
DEBU[0002] Dedup SSH Key SHA256:XSN/741107mJBUr1OLiUEGZTBlB2pMdGceTgwITDlvU ssh-ed25519 

[jwhonce]

@ashley-cui Understood. If you provide that identity file, I need the passphrase to read it before I can dedup the list of keys to throw it away... hen vs egg issue

[ashley-cui]

merging as-is to clean up some use cases, knowing RSA and the public key with identity file issues exist
LGTM

[ashley-cui]

@containers/podman-maintainers PTAL

[TomSweeneyRedHat]

LGTM

[ashley-cui]

/lgtm