Re: pie-in-sky idea: 'sensitive' function parameters - Mailing list pgsql-hackers

From Craig Ringer
Subject Re: pie-in-sky idea: 'sensitive' function parameters
Date
Msg-id CAMsr+YEbT5Mvcs+HnZcQvrz74EEyusyjOTDP_3k+DO9jVN5XmQ@mail.gmail.com
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In response to Re: pie-in-sky idea: 'sensitive' function parameters  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 3 February 2018 at 11:46, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Chapman Flack <chap@anastigmatix.net> writes:
> ... which led me to the idea of a function parameter
> declaration, putting the function definer in control of what
> bits should get redacted.

+1 for thinking outside the box, but ...

> Would anyone else see some value in this capability? Could it
> (or some suitable restriction of it) seem implementable, or would
> the complications be overwhelming?

... the problem with this idea is that knowledge that the item ought to be
hidden would be obtained only very late in the parsing process.  So for
example if you fat-fingered something just to the left of the function
call in the query text, or the name of the function itself, your password
would still get exposed in the log.

This indeed is the core problem with every proposal I've seen for
semantics-based log filtering.  Error logging needs to be considered
as a very low-level operation, because reports may come out when
little if anything is known about the real semantics of the query.

 
About the only time I think it's really viable to pursue is if it's restricted to bind parameters. We only log those later and more selectively as it is, so it seems much more reasonable to say "I never want <parameter X> to appear in the logs".

That said, I'm not sure it can be done at the function-interface level, or if it'd have to be done in the Bind message to make it reliable and available early enough.

--
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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