[Phpmyadmin-devel] Limits imposed by Suhosin

Marc Delisle marc at infomarc.info
Sun Aug 7 13:39:55 CEST 2011


Le 2011-08-07 07:31, Tyron Madlener a écrit :
> On Sun, Aug 7, 2011 at 2:06 PM, Marc Delisle <marc at infomarc.info> wrote:
>> Le 2011-08-06 07:59, Madhura Jayaratne a écrit :
>>> Hi all,
>>>
>>> While attending to a bug [1], I came across the following.
>>> Suhosin imposes a limit of 512 on the length of the variable that can be
>>> passed via a GET [2]. This is often problematic as in PMA we encounter long
>>> parameters (long sql queries, where clauses when no unique key is there
>>> etc). Due to the same problem [3] $cfg['LinkLengthLimit'] configuration was
>>> lowered to more stricter 1000 from 2000, which is more acceptable.
>>>
>>> In this particular bug the problem is that, though the URL length is under
>>> 1000, one parameter, 'sql_query', violates the Suhosin limit. What
>>> should be our stand on this. Should we adhere to Suhosin default values?
>>>
>>> In 3.5 we have a possible solution for this [4] and we can still lower
>>> $cfg['LinkLengthLimit'] value without losing the look and feel. However this
>>> needs to have JS enabled and I'm not sure whether we want to impose that
>>> condition for the 3.4 series.
>>
>> Madhura,
>> see Documentation.html, FAQ 1.38. You might want to add a suggestion
>> there about suhosin.get.max_value_length.
>>
>> As you can deduce from this FAQ entry, it was not our intention to adapt
>> to Suhosin's limits.
> 
> Would there be any problem in using min($cfg['LinkLengthLimit'],
> [suhoins max length]) for pma?

You might have a good start of solution, but $cfg['LinkLengthLimit'] is
for the total length of the link, whereas suhosin.get.max_value_length
is per parameter and we have more than one parameter in those links.

-- 
Marc Delisle
http://infomarc.info




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