Re: MD5 and URL validation (continue to other very old thread)

ons 2012-11-21 klockan 21:06 +0200 skrev Eliezer Croitoru:

> The problem is that it only being checked while a file is being fetched
> from UFS(what I have checked) while from RAM it wont be checked.

There is no risk of object store displacement in RAM.

> The result is that when store_url_rewrite feature is being used the
> check points on inconsistency between the request url and the object in
> cache_dir (naturally).

The metadata URL should be the store_url, not requested URL.

> After a small talk with alex I sat down and made some calculations about
> MD5 collision risks.
> The hash used to make the index hash is a string from "byte + url".
> For most caches that I know of there is a very low probability for
> collision considering the amount of objects and urls.

Verifying the MD5 is sufficient. But either MD5 or URL MUST be verified
in metadata on objects fetched from disk.

Regards
Henrik
Received on Thu Nov 22 2012 - 08:35:33 MST