Unpack! Crack! Reverse!

 

Due some agreement with Gigabyte, my webmistress, I cant have binaries in the page. Instead of giving you some password protected ZIP files, or keeping the binaries in another server, I resolve give you the original ZIP files, with the binaries inside, but crippled - you will get CRC errors while trying to unzip the binaries!! Here's the tool I used to crypt the binaries inside ZIP files. If you want have access to the binaries in my site, you can either recompile the sources, or reverse this tool, making another one that undo the effects of this one. Its not hard: there's no password or like, all info you need is inside the ZIP. As peoples interessed in the binaries are usually collectors, and collectors usually cant code, I would had few hope that somebody even try my challenge, so i also crypted some sources. The kewl ones. ;-) This way, i hope, some coder would give a try, in order to get hands over the source codes (that are what matter).

Give it a try! Its a very easy crackme/reverseme!

 

 

THE KNAPSACK PROBLEM!

Other challenge you maybe will find in my page are the .KNS files. These files are encrypted by this tool (sources code included), that use knapsack public/private cryptography to make sure that only who have the PRIVATE.KEY file corresponding to the included PUBLIC.KEY file can decrypt and view the file.

The knapsack system was the first developed assymetric cryptosystem, and was already proved to be insecure. Somebody that have the public key can easily generate the private key. When it was breaked, the demonstration was done in a Apple2 computer!

Thus, if you want read the .KNS files, you will have to obtain a copy of the PRIVATE.KEY corresponding to the PUBLIC.KEY that was used to encrypt the file (the one included in KNAPSACK.ZIP)

Here´s the solution for the ZIPCrypt challenge, in .KNS format.

 

RSA

Files with the extension .rsa where made with this tool. Altought the source code of the tool for decrypting is included, its incomplete, as the private key was included. So, if you want these .rsa files, extract and factor the public key, or find other way around ;-)

Some peoples maybe have problems running RSACRACKME. For these ones, DoxtorL coded a little DLL. Put this DLL in same directory than RSACRACKME, and change the import table of it from KERNEL32.DLL to KERNEL33.DLL.

 

 

 

The solutions

 

ZIPCRYPT

uNdErX *	Manual decryption with SOFTICE
KRIO	Code + Tute
L!B	Code + Tute
malfunction	Code + Tute
comrade	Code + Tute

* Others also decrypted it manually, but i dont remember the nicknames. E-mail me if you´re one of these.

 

KNAPSACK

DoxtorL	Bruteforcer
L!B	Bruteforcer (it work?)
edcba	Bruteforcer (very fast)
DoxtorL	Bruteforcer (even faster)

 

RSA

DoxtorL

Code + Tute