[Typo3-dev] Empty cHash problem

[Elmar Hinz]

Elmar Hinz wrote:
> Kasper Skårhøj wrote:
> 
>>> Wouldn't it also happen when
>>>
>>> a) ...
>>> b) ...
>>> c) a cHash is given but a wrong one
>>
>>
>>
>> Nope, it will not. The problem as described in that article is 
>> specifically dealing with an empty value of cHash. A value found will 
>> trigger a verification process that afaik works just fine.
>>
>> - kasper
> 
> 
> Hello Kasper,
> 
> Thank you for precise ansewer. I will reflect about this point.
> 

O.k. I got the point now. If an invalid cHash is discoverd, caching is 
disabled. The content can still be delivered dynamically but it isn't 
cached.

<cite http://typo3.org/development/articles/the-mysteries-of-chash/page/2/>

In case the enemy had changed “&tx_myext[uid]=9876554321” in order to 
spam our cache table the resulting hash string generated will with all 
probability not match “13b5d6efa7”: Page caching will be disabled 
immediately, but the page will still be generated trying to display news 
item  9876554321 (which probably does not exist, but so what? The cache 
table is not loaded with that...)
</cite>


Now for delivery (not for caching):

What happens if:

a) the additional parameters are sensible
b) the according view is already cachecd
c) but the cHash is empty or wrong (because of a defect external link)

1.) Is the view created dynamically?
2.) Is it deliverd from the cache?

Elmar








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