Russian Dolls

[Nihlaeth]

I started manually at my linux server, but after about 300 times renaming, unzipping and using the file command I gave up and started to look up the bash basics...

I could have guessed the answer easily, but I didn't know that in advance :p

However, I must say I really learned something on this one, thanks!

[Curiosu]

used this php function ..it was a pain, first I thought it was simple zip,

Code: Select all

     function extractGzip ($src, $dest=false)
    {
        $zp = gzopen( $src, "r" );
       if (!is_resource($zp)) return false;
        $data = '';
        while (!gzeof($zp))
            $data .= gzread($zp, 1024*1024);
        gzclose( $zp );
        if (empty($dest)) return $data;
        elseif (file_put_contents($dest, $data)) return true;
        return false;
    }

And my code was bugged, and runned the func for like 15k times, but it was fun

[laz0r]

It's really easy under Mac OS - it will do all the unarchiving at once if you ask it to unarchive a file. It just meant sitting waiting for it to finish, and renaming the files every now and again (because Mac OS appends ' 2' onto the archive each iteration, and they get far too long).

[driest]

Python solution:

Code: Select all

import gzip
while 1:
    f = gzip.open('doll.bin', 'rb')
    content = f.read()
    f.close()
    out = open('doll.bin', 'wb')
    out.write(content)
    out.close()

[junkpete]

under mac os x you only have to click about 10 times, it automatically extraxts but stops when the filename is too long

[al_paz]

i guessed the answer... first tried "babushka" and then the correct one.

[kjangwa]

No way, such good solutions, this took me ages.
first copied 7z.exe and 7z.dll into sys32 so 7zip would work from cmdline then wrote this python script.
renamed doll.gz to doll1.gz

Code: Select all

import os

for i in range(1,1000):
    unzip="doll"+str(i)
    q=i+1
    name="doll"+str(q)
    
    os.system("7z e "+unzip+".gz")
    print "unzipped",unzip
    print "renamed to ",name
    os.rename(unzip, name+".gz")

I didnt realize till now that 7zip would unzip a file without a .gz extension

[Millennium]

I did it in C++ XD

[awf]

I solved this like "mystery file" by pressing the unpack shortcut
in 7-zip until the solution was found.

Does somebody know how this .bin-packing works? I first tried
to write a script from hand to solve "mystery file" but the input
string from the file is seemingly random hex-numbers that aren't
connected to the solution obtained by 7-zip.

[FreeFull]

I solved this like "mystery file" by pressing the unpack shortcut
in 7-zip until the solution was found.

Does somebody know how this .bin-packing works? I first tried
to write a script from hand to solve "mystery file" but the input
string from the file is seemingly random hex-numbers that aren't
connected to the solution obtained by 7-zip. :?

It's just simple gzip encryption

[rain1024]

Finally I got it
It's nice challenge
But seem all comment too open???

I wrote a script to get answer.

[hut]

At first I did it with aunpack which is a wrapper for unpacking any kind of archives. But with each unpack, the file size got doubled... then I read the hint that it's 999 layers and I thought damn, I dont have 10^9999 GB here :(
but luckily it worked fine using gzip directly.

[bspus]

Too bored to boot a live linux just for the file command
I couldn't get 7z to report the file type. Then after I solved it, I noticed it was in file-properties all along... duh!

renaming it to doll.bin.zip worked anyway. 7z does not care about the corect extension.
Then I used the following batch file

Code: Select all

@echo off

set /a counter=0

:top
ren doll.bin doll.bin.zip
7z x doll.bin.zip
del doll.bin.zip
set /a counter+=1
if %counter% LEQ 996 goto :top

:end
exit

I knew aready that it was 999 times compressed so i left a few out just in case

[Schnapphahn]

bat using 7zip did it.

[chc4]

Used a C# 7zip wrapper dll. Came out around 10 lines long ^_^