[Freeipa-devel] using pyhbac for CA ACLs

[Fraser Tweedale]

Hi everyone,

CA ACLs (the forthcoming `caacl' plugin) will be used to declare
which users/hosts/services can get certificates from which CAs and
profiles.  For v4.2, we will enforce the ACLs in the framework; the
plan is to move ACL enforcement to Dogtag in a future release
(https://fedorahosted.org/freeipa/ticket/5011).

I have written most of the caacl plugin and now I must update
cert-request to enforce the ACLs.  Using hbacrule as the guide, I
had a look at pyhbac and it seems to be a reasonable fit for
implementing this.  In particular:

- "targethost" and "service" correspond nicely to "(sub)CA" and
  "profile-id" for evaluation.

- A certificate request can be for a user, host or service; these
  will be overloaded into the pyhbac "user" concept.  But because we
  will always know who the requesting principal is, we will only
  ever need to deal with whatever of {user,host,service} the
  principal actually is, to be able to evaluate access.

- The "srchost" concept will be unused (therefore fixed to
  HBAC_CATEGORY_ALL).  Perhaps there could be some future use.

So, please provide feedback if you think this is a great idea or a
terrible idea :)

Thanks,
Fraser