Bug 3412

Summary: ssh_config(5): more clearly describe PubkeyAuthentication values
Product: Portable OpenSSH Reporter: Christoph Anton Mitterer <calestyo>
Component: DocumentationAssignee: Assigned to nobody <unassigned-bugs>
Status: NEW ---    
Severity: enhancement CC: djm
Priority: P5    
Version: 8.9p1   
Hardware: Other   
OS: All   

Description Christoph Anton Mitterer 2022-03-23 10:24:07 AEDT
Hey.

Would it be possible to describe the values for PubkeyAuthentication more clearly?

"yes" and "no" are probably clear, simply enabling/disabling *any* PubkeyAuthentication.

But for "unbound" and "host-bound" it merely says:
"The final two options enable public key authentication while respectively disabling or enabling the OpenSSH host-bound authentication protocol extension required for restricted ssh-agent(1) forwarding."

Okay... so they both enable PubkeyAuthentication... but "unbound" disables the ssh-agent extension, while "host-bound" enables them?

Shouldn't that mean that one of them ("unbound"?) is synonymous to "yes"?

And which of them would be the more restricted options? Since that ssh-agent extension, AFAIU, can only restrict (further), then "host-bound" should be the safest choice?

Thanks,
Chris.
Comment 1 Damien Miller 2022-03-23 10:43:57 AEDT
There's no more restrictive option - the restriction is performed in ssh-agent. The other options are mostly for debugging and regression testing.