Re: [PATCH] Fix leaky VIEWs for RLS

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: KaiGai Kohei <kaigai@ak.jp.nec.com>, Robert Haas <robertmhaas@gmail.com>, marc@bloodnok.com, pgsql-hackers@postgresql.org
Date: 2010-06-04T14:33:57Z
Lists: pgsql-hackers
Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> On 04/06/10 07:57, Tom Lane wrote:
>> The proposal some time back in this thread was to trust all built-in
>> functions and no others.

> I thought I debunked that idea already 
> (http://archives.postgresql.org/pgsql-hackers/2009-10/msg01428.php). Not 
> all built-in functions are safe. Consider casting integer to text, for 
> example. Seems innocent at first glance, but it's not; if the input is 
> not a valid integer, it throws an error which contains the input string, 
> revealing it.

Hmm ... that's a mighty interesting example, because it shows that any
well-meaning change in error handling might render seemingly-unrelated
functions "unsafe".  And we're certainly not going to make error
messages stop showing relevant information just because of this.

Maybe the entire idea is unworkable.  I certainly don't find any comfort
in your proposal in the above-referenced message to trust index
operators; where is it written that those don't throw errors?

			regards, tom lane