* Neil Tiffin (neilt@neiltiffin.com) wrote:
> On May 4, 2014, at 3:17 PM, Stephen Frost <sfrost@snowman.net> wrote:
> > Any system where there exists a role similar to 'superuser' in the PG
> > sense (a user who is equivilant to the Unix UID under which the rest of
> > the system is run) would be hard-pressed to provide a solution to this
> > issue.
>
> Not sure I understand which issue you are referring to. If you are referring to 'cannot be turned off', I would
thinka reasonable first pass would be to handle it similar to '--data-checksums' in 'initdb'. For example, "This
optioncan only be set during initialization, and cannot be changed later. If set, basic auditing is on for all objects,
inall databases."
Well, except that a superuser *could* effectively turn off checksums by
changing the the control file and doing a restart (perhaps modulo some
other hacking; I've not tried). That kind of trivial 'hole' isn't
acceptable from a security standpoint though and given that we couldn't
prevent a superuser from doing an LD_PRELOAD and overriding any system
call we make from the backend, it's kind of hard to see how we could
plug such a hole.
> > With SELinux it may be possible and I'd love to see an example
> > from someone who feels they've accomplished it. That said, if we can
> > reduce the need for a 'superuser' role sufficiently by having the
> > auditing able to be managed independently, then we may have reached the
> > level of "considerable headache".
> >
> > As many have pointed out previously, there is a certain amount of risk
> > associated with running without *any* superuser role in the system
>
> If all of the superuser's actions are logged and it's not possible to turn off the logging (without considerable
headache)then it may not matter what the superuser can do. If the superuser makes changes and they are logged then the
auditorshave sufficient information to see if the correct procedures were followed. Validated systems are based on
tracking,not necessarily prohibiting. Select individuals that should be able to be trusted (which should apply to
superusers)should be able to perform the actions necessary to support the organization.
Fair enough- the question is just a matter of what exactly that level of
"headache" is.
Thanks!
Stephen