[bug#53901] [PATCH] publish: Sign only normative narinfo fields.

[pukkamustard]

Ludovic Courtès <ludo@gnu.org> writes:

> This will allow mirror operators to alter the non-normative bits of a
> narinfo, such as nar URLs and compression methods, without requiring
> them to resign narinfos.
>
> [...]
>
> Thoughts?

Sounds good to me.

Maybe we can take the opportunity to do some cleanup?

For example: We could get rid of the narinfo-contents field as we only
sign the fixed normative fields (in a strict order). This would also
allow us to remove the verify-everything-above-signature logic.

I recently tripped over the narinfo verification logic
(https://issues.guix.gnu.org/52555#43) and think the changes you propose
plus the simplifications above should make this security-critical code a
bit easier to understand.

-pukkamustard