Re: [RFC] A tackle to the leaky VIEWs for RLS

On Tue, Jun 1, 2010 at 4:10 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
> On Tue, Jun 1, 2010 at 1:28 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> On Tue, Jun 1, 2010 at 1:02 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>>>> On Tue, Jun 1, 2010 at 10:57 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>>> CREATE SECURITY VIEW, anyone?
>>>
>>>> That may be the best approach, but I think it needs more than one line
>>>> of exposition.  The approach I proposed was to test whether the user
>>>> has privileges to execute the underlying query directly without going
>>>> through the view.  If so, we needn't be concerned.  If not, then we
>>>> start thinking about which functions/operators we trust.
>>>
>>> Ummm ... that makes semantics dependent on the permissions available at
>>> plan time, whereas what should matter is the permissions that exist at
>>> execution time.  Maybe that's all right for this context but it doesn't
>>> seem tremendously desirable.
>>
>> Ugh.  I hope there's a way around that problem because AFAICS the
>> alternative is a world of hurt.  If we're not allowed to take the
>> security context into account during planning, then we're going to
>> have to make worst-case assumptions, which sounds really unpleasant.
>>
>>>> Perhaps there is some value to having a knob that goes the opposite
>>>> directions and essentially says "I don't really care whether this view
>>>> is leaky from a security perspective".  But presumably we don't want
>>>> to deliver that behavior by default and require the user to ask for a
>>>> SECURITY VIEW to get something else - if anything, we'd want CREATE
>>>> VIEW to create the normal (secure) version and add CREATE LEAKY VIEW
>>>> to do the other thing.
>>>
>>> -1 on that.  We will get far more pushback from people whose application
>>> performance suddenly went to hell than we will ever get approval from
>>> people who actually need the feature.  Considering that we've survived
>>> this long with leaky views, that should definitely remain the default
>>> behavior.
>>
>> Eh, if that's the consensus, it doesn't bother me that much, but it
>> doesn't really answer the question, either: supposing we add an
>> explicit concept of a security view, what should its semantics be?
>
> have you ruled out: 'create function'? :-)

You lost me...

--
Robert Haas
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