Re: SE-PostgreSQL/Lite Review

Stephen Frost wrote:
> Josh,
>
> * Joshua Brindle (method(at)manicmethod(dot)com) wrote:
>> Stephen Frost wrote:
>>> I do think that, technically, there's no reason we couldn't allow for
>>> multiple "only-more-restrictive" models to be enabled and built in a
>>> single binary for systems which support it. As such, I would make those
>>> just "#if defined()" rather than "#elif". Let it be decided at runtime
>>> which are actually used, otherwise it becomes a much bigger problem for
>>> packagers too.
>> It isn't just a case of using #if and it magically working. You'd need a
>> system to manage multiple labels on each object that can be addressed by
>> different systems. So instead of having an object mapped only to
>> "system_u:object_r:mydb_t:s15" you'd also have to have it mapped to,
>> eg., "^" for Smack.
>
> I'm not sure I see that being a problem.. We're going to have
> references in our object managers which make sense to us (eg: table
> OIDs) and then a way of mapping those to some label (or possibly a set
> of labels, as you describe). We might want to reconsider the catalog
> structure a bit if we want to support more than one at a time, but I
> don't see it as a huge problem to support more than one label existing
> for a given object.

If we allow multiple security labels on a database object, we have to
expand the structure of system catalog whenever a new security feature
will come in. I think it against to the purpose of the framework.

Even if we store them external relations to reference the object by OID,
we have to provide multiple interface to import/export a security label
for each enhanced securities. For example, it requires much complex patch
to the pg_dump.

My preference is all the enhanced securities shares a common facility
to manage security label, a common statement support and a common
backup/restore support.

Thanks,
--
KaiGai Kohei <kaigai(at)kaigai(dot)gr(dot)jp>