Re: Row Level Security − leakproof-ness and performance implications - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Row Level Security − leakproof-ness and performance implications
Date
Msg-id CA+Tgmob2-5HjqgRYVdyg-oaY-h8Q=t=9UwWS+0=m1Tp_jLrDnQ@mail.gmail.com
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In response to Re: Row Level Security − leakproof-ness and performance implications  (Joe Conway <mail@joeconway.com>)
Responses Re: Row Level Security − leakproof-ness and performance implications  (Joe Conway <mail@joeconway.com>)
List pgsql-hackers
On Thu, Feb 28, 2019 at 11:14 AM Joe Conway <mail@joeconway.com> wrote:
> > Although, and Joe may hate me for saying this, I think only the
> > non-constants should be redacted to keep some level of usability for
> > regular SQL errors. Maybe system errors like the above should be
> > removed from client messages in general.
>
> I started down this path and it looked fragile. I guess if there is
> generally enough support to think this might be viable I could open up
> that door again, but I don't want to waste time if the approach is
> really a non-starter as stated upthread :-/.

Hmm.  It seems to me that if there's a function that sometimes throws
an error and other times does not, and if that behavior is dependent
on the input, then even redacting the error message down to 'ERROR:
error' does not remove the leak.  So it seems to me that regardless of
what one thinks about the proposal from a usability perspective, it's
probably not correct from a security standpoint.  Information that
couldn't be leaked until present rules would leak with this change,
when the new GUCs were turned on.

Am I wrong?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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