Tildes are not expanded from .ssh/config

[JonathanDoughty]

Tildes used in .ssh/config for specifying IdentifyFile paths relative to the HOME directory are not expanded by keychain as part of all_host_identities. The --confallhosts flag then will not find those keys because tilde expansion will not have occurred when the $keyf variable is expanded as part of the if [ -f "$keyf" ]; then check.

I've created a patch that corrects this that I submitted as a PR

[joshsleeper]

nice, thanks for tracking that down! I'd noticed the same thing when --confallhosts was first implemented but failed to get around to reporting it 🫠

fwiw I'll note that ssh_config happily accepts ~, %d, and ${HOME} as placeholders for the user's homedir (at least according to the manpage), none of which keychain currently handles properly unfortunately.

• %d docs: https://www.man7.org/linux/man-pages/man5/ssh_config.5.html#TOKENS
• ${HOME} docs: https://www.man7.org/linux/man-pages/man5/ssh_config.5.html#ENVIRONMENT_VARIABLES

unfortunately I couldn't really find a simple, programmatic way to get those absolute paths out of ssh.
I'm thinking that the pratical solution might be to just extend your PR to account for %d and ${HOME} prefixes as well?

EDIT: oh, something else I noticed after I posted this is that apparently double-quoted arguments are also valid, and I don't think we account for that either anywhere. quote below from the manpage description.

The file contains keyword-argument pairs, one per line. Lines starting with # and empty lines are interpreted as comments. Arguments may optionally be enclosed in double quotes (") in order to represent arguments containing spaces.

EDIT2: aight, I guess I nerd-sniped myself into trying to cover all those edge cases of ssh_config parsing, so I opened #199 as an alternate to #197 😅