Re: contrib: auth_delay module

On Thu, Nov 4, 2010 at 10:04 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Thu, Nov 4, 2010 at 6:35 AM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:
>> * Jan Urbański (wulczer(at)wulczer(dot)org) wrote:
>>> On 04/11/10 14:09, Robert Haas wrote:
>>> > Hmm, I wonder how useful this is given that restriction.
>>>
>>> As KaiGai mentined, it's more to make bruteforcing difficult (read: tmie
>>> consuming), right?
>>
>> Which it would still do, since the attacker would be bumping up against
>> max_connections.  max_connections would be a DOS point, but that's no
>> different from today.  Other things could be put in place to address
>> that (max # of connections from a given IP or range could be implemented
>> using iptables, as an example).
>>
>> 5 second delay w/ max connections at 100 would mean max of 20 attempts
>> per second, no?  That's alot fewer than 100*(however many attempts can
>> be done in a second).  Doing a stupid while true; psql -d blah; done
>> managed to get 50 successful ident auths+no-db-found errors done in a
>> second on one box here.  5000 >> 20, and I wasn't even trying.
>
> OK.  I was just asking.  I don't object to it if people think it's
> useful, especially if they are looking at it as "I would actually use
> this on my system" rather than "I can imagine a hypothetical person
> using this".

I haven't heard anyone say "yes, I would actually use this on my
system"? Any takers?

If we're to commit this, then the patch needs to add a new file
authdelay.smgl, fill it in with appropriate contents, and update
contrib.sgml and filelist.sgml accordingly. I also note that the
patch offers the ability to log superuser logins. Since that seems a
bit off-topic for a contrib module called auth_delay, and since we
already have a GUC called log_connections, I'm inclined to propose
removing that part.

--
Robert Haas
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