Re: Converting contrib SQL functions to new style

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Wed, Apr 14, 2021 at 1:41 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Could we hack things so that extension scripts are only allowed to
>> reference objects created (a) by the system, (b) earlier in the
>> same script, or (c) owned by one of the declared prerequisite
>> extensions? Seems like that might provide a pretty bulletproof
>> defense against trojan-horse objects, though I'm not sure how much
>> of a pain it'd be to implement.

> That doesn't seem like a crazy idea, but the previous idea of having
> some magic syntax that means "the schema where extension FOO is" seems
> like it might be easier to implement and more generally useful.

I think that's definitely useful, but it's not a fix for the
reference-capture problem unless you care to assume that the other
extension's schema is free of trojan-horse objects. So I'm thinking
that we really ought to pursue both ideas.

This may mean that squeezing these contrib changes into v14 is a lost
cause. We certainly shouldn't try to do what I suggest above for
v14; but without it, these changes are just moving the security
issue to a different place rather than eradicating it completely.

regards, tom lane