Need to restore zeroed file

[Ed Kapitein]

On 07/09/15 21:00, Roland Haeder wrote:
> Hello all,
>
> bad news: One of my files in my storage got zeroed and I don't have the
> old (working) URI or up-to-date backup (only from 2013).
>
> I have currently written a brute-forcer which currently *should* test
> all possibilities. Sure this needs massive improvement.
>
> So I need to know something:
>
> 1) Is this URL pattern valid:
>
> http://127.0.0.1:3456/file/URI%3ACHK%3A<key1>%3A<key2>%3A3%3A10%3A<num>/@@named=/<filename>
>
> by:
> <key1> = 26 Byte long character consisting of a BASE32 checksum
> <key2> = 52 Byte long character consisting of a BASE32 checksum
> <num>  = Random number from 0 to 99999
> <filename> = The file's name without path
>
> 2) Is z_base_32_alphabet or rfc3548_alphabet taken as an alphabet?
>
> 3) Do I calculate this correctly?
>
> 26 length, each can have 32 different characters (key1)
>
> This means 1*32^26 =
> 1361129467683753853853498429727072845824
>
> possibilities?
>
> And
> 1852673427797059126777135760139006525652319754650249024631321344126610074238976
>
> possibilities for key2?
>
> 3) Do I *really* have to brute-force them all to find the correct URI?
> Or can someone (I don't like to paste brute-forcer publicly) improve the
> search algorithm?
>
> Regards,
> Roland
>
Well, without doing the actual math, i think our sun has died before you 
can bruteforce key1*key2*99999.
Do you have the storage index for the lost file? that might give you a 
fighting change to get the content back.

Kind regards,
Ed