I synchronise my .ssh/config
file between (most of) my laptops, including some Linux and macOS ones. On Mac, it’s quite nice to be able to use the UseKeychain option to store SSH passphrases in the secure keychain thing.. until you then try to use the same config
file on Linux that is..!
Thankfully, the IgnoreUnknown option can be used to tell Linux to stop whining about a bad configuration option, like so:
Host [heheh no]
User theresnotime
IdentityFile ~/.ssh/keys/path/to/key
AddKeysToAgent yes
IgnoreUnknown UseKeychain
UseKeychain yes
However, Linux (Is it a Debian thing? Is it an OpenSSH thing? Who knows…) sometimes decides to ignore the inline IgnoreUnknown UseKeychain
and instead present the error SSH: Bad configuration option: usekeychain
for fun or something.
This tends to occur just as I’m urgently having to SSH into something, so my solution is to edit .ssh/config
and remove the UseKeychain
lines in a huff.
Adding
Host *
IgnoreUnknown UseKeychain
to the top of .ssh/config
seems to have fixed that, as sorta suggested by https://www.unixtutorial.org/ssh-bad-configuration-option-usekeychain :-)
The more you know, etc.