Bruce,
> I think the community's priorities are to add security at the SQL
> level, and then we can see clearly what SE-PostgreSQL requires. This
> has been discussed before so it should not come as a surprise.
Well, I'm not that clear on exactly the SE implementation, but I spent a
fair amount of time with Trusted Solaris and I can tell you that a
multilevel security implementation would work in a different way from SQL
row-level permissions.
Multilevel frameworks have concepts of data hiding and data substitution
based on labels. That is, if a user doesn't have permissions on data,
he's not merely supposed to be denied access to it, he's not even supposed
to know that the data exists. In extreme cases (think military / CIA use)
data at a lower security level should be substitited for the higher
security level data which the user isn't allowed. Silently.
So it's quite possible that the SE and/or multilevel framework could remain
parallel-but-different from SQL-level permissions, which would not include
data hiding or data substitution.
--
--Josh
Josh Berkus
PostgreSQL
San Francisco