feat: Add keyctl support. Closes #103

[alexec]

This adds support for keyctl. This is only used if dbus does not work, otherwise it would break existing users.

It is not persistent, i.e. reboots loose data. This is desirable for my use case.

Closes #103.

[alexec]

@szuecs please can I request review.

[ossenthusiast]

@alexec

• https://man7.org/linux/man-pages/man7/persistent-keyring.7.html
• https://man7.org/linux/man-pages/man3/keyctl_get_persistent.3.html

[alexec]

@ossenthusiast I asked Copilot and it says that does not survive reboots unfortunately. It does survive logins. I think it is the right direction.

[alexec]

kitproj#1

[alexec]

@mikkeloscar please can I request your review on this PR?

[szuecs]

I am a bit biased against crap comments by AI machines. Can you cleanup all useless comments?
Some are useful, but scrolling over the code I would say it's a lot useless.

[alexec]

@szuecs copilot has addressed your comments.

[alexec]

@szuecs I've had Copilot move the composite provider to its own file and make the code easier to understand and revert the changes to existing comments.

[alexec]

@szuecs can I please bump this to the top of your inbox? I'm hoping to use this on a project that will soon be ready to ship, but cannot run on dbus systems. It will only run where there is keyutils installed (headless systems).

Thank you.

[alexec]

@szuecs can I bump this please? For the moment, I'm going to release a fork of this.