nickodell/hourglassbreaker

Open files protected by Hourglass by bruteforcing the underlying key

HourglassBreaker

This is a python program that can open files encrypted by Hourglass by bruteforcing the key protecting the file.

It does not matter how many iterations you've set in Hourglass, because the underlying encryption is only 16-bit.

A test vector is included. HourglassBreaker works best on medium length messages. If it's too short, then the CRC isn't effective, and multiple keys produce a file that checksums correctly. The longer the file is, the longer HB will take.

This works as of commit 8cf7c8c.

Example usage

$ time ./bruteforce.py todecrypt
Solution found!
key = 0x2a4f
plaintext = b'Lorem ipsum dolor sit amet, consectetur adipiscing elit.\n'
flags = 2

real	0m3.239s
user	0m3.240s
sys	0m0.000s

License

GPLv3

Dependencies

Python 3

Bugs

Doesn't support qCompress. If you get 'flags = 3' and a bunch of gobbledygook, that's because the data is compressed.