Add support for request_key and keyctl_instantiate

[mythi]

Fixes: #12

[landhb]

@mythi Thanks for the PR!

It looks great, will try to finish the review this weekend. Left one comment for your question about "NULL" callouts.

[mythi]

It looks great, will try to finish the review this weekend. Left one comment for your question about "NULL" callouts.

Thanks, I think the comment is missing (at least I cannot see it).

I pushed one small fix to examples/keyctl (changed keyring to ring because of a conflicting -k shorname for key/keyring)

[landhb]

I think having this as Option<&C> and then updating ffi::request_key to provide core::ptr::null when the Option is None would be nice from a user perspective. Instead of checking for ""

[mythi]

I thought about the same but dropped the idea in the initial ver. I've have that now implemented. AFAUI, Option<&C> wants type hint so the param becomes None::<&str>.

[mythi]

(pushed with one lint error fixed that I just discovered)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 45.00000% with 22 lines in your changes missing coverage. Please review.
✅ Project coverage is 65.51%. Comparing base (2e81f72) to head (5811f27).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
src/key.rs	0.00%	16 Missing ⚠️
src/ffi/types.rs	40.00%	3 Missing ⚠️
src/errors.rs	0.00%	2 Missing ⚠️
src/keyring.rs	83.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #13       +/-   ##
===========================================
- Coverage   78.33%   65.51%   -12.82%     
===========================================
  Files           9        9               
  Lines         420      319      -101     
===========================================
- Hits          329      209      -120     
- Misses         91      110       +19     

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[landhb]

@mythi Sorry for the delay. Just added a small request-key program that we can install to /sbin/request-key to run your tests in CI/CD.

Also added Key::assume_authority for that usage.

https://github.com/landhb/linux-keyutils/blob/main/examples/request-key.rs

Will get this out in the next release.

[mythi]

@landhb thanks!