dbsynergy wins the first challenge

Categories: Challenges

Congratulations to dbsynergy for solving the first SF2600 challenge! nodus and yotta completed the challenge second and third respectively.

To celebrate the completion of the site, a hacking challenge was posted in the Terminal section. The challenge involved reversing of the algorithm used to encrypt passwords of JS/UIX OS and recovering of the root password.

Below are several code snippets used to solve the challenge. Everyone found the encrypted password in jsuix_krnl.js and correctly reversed the algorithm:

//dbsynergy's Quick 'n Dirty Solution
var printable = new

var decrypted = '';
var currentTest = '';
for(var i=0; i < conf_rootpassskey.length; i+=2){
      for(var p=0; pprintable.length; p++){
              if(krnlCrypt(currentTest+printable[p]) ==
                      currentTest += printable[p];

This algorithm has a slightly longer runtime, because it iterates over entire alphabet. This can be optimized a bit more by decoding the string character by character as as done in the next example.

#nodus's Algorithm Decode Solution

import re
#from line 50 of jsuix_krnl.js
while '' in pairs:

#got this from the js console in chromium with
keys=[14, 122, 255, 33] 
for str_pair in pairs:


for i in numbers:
   number = (i-last)-keys[count%4]
   while number <1:
for i in numbers2:
print string

It took nodus a bit longer (15 minutes to be exact) to write a complete decoder. While the code looks a bit longer, it is actually more efficient (no nested loops and reverses the algorithm character by character).

iphelix's Masochist Calculator Solution
If you feel like torturing yourself a bit, you can
solve the puzzle manually with a piece of paper 
and a calculator ;-)

The algorithm went along something like this:

Hash = 73 5A BB 3D BD 9A FA 7F F2 DE 4C
Salt = 0e 7a ff 21

0x73 - 0x0e - 0 [+0x100]    = 'e'
0x5A - 0x7a - 73 [+0x100]  = 'm'
0xBB - 0xff - 5A [+0x100]   = 'b'
and so on...

Well I hope everyone enjoyed the challenge, I will cook up something more evil for the next one.

Feel free to design and submit your own challenges to the site.

Posted by iphelix on Apr 06, 2011
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