![brew install mongodb fail bad substitution brew install mongodb fail bad substitution](https://files.vinta.ws/code/wp-content/uploads/2018/03/fig-12-03-2018_17-19-44.jpg)
However, people had a lot of trouble completing it, as the word I've chosen was only in some dictionaries. Since GIF header is known, it was very easy to figure out the first few letters of the key. The challenge was then to find out which Twitter account the image is from. A GIF file was xor-encrypted with a word from a dictionary.
![brew install mongodb fail bad substitution brew install mongodb fail bad substitution](https://i1.wp.com/www.tutorialsjar.com/wp-content/uploads/2017/04/Installing-MongoDB-on-Windows-Mac-2.jpg)
People had a lot of trouble figuring out dimensions and bit depth of the image, which had to be given as a hint, even thought they were fairly usual. It was basically a version of the famous ECB penguin from Wikipedia. Other than using unusual characters, obfuscations applied weren't particularly hard. It used two layers of Unicode obfuscation, first with emoji, and then with CJK characters. Obfuscated Ruby challenge was the hardest one of the round. Once a person figured out what the challenge is about, it wasn't usually too hard to solve it. Quite a few people used editors which cleaned up whitespace automatically, messing up with the file. So I encoded some secrets in the whitespace. Everybody managed to finish it so quickly, I didn't even have a chance to see what kind of tools they used to solve it.ĮDIT: Oops, it seems that I messed up ImageMagick options and also accidentally left the answer in EXIF.Īs we all know Python is a whitespace-sensitive language. The answer was written in one color on background of another extremely similar color. It was very short, and every character was independent, so it seems that everyone just manually brute forced it. I've never seen this kind of challenge anywhere, so maybe it's the world's first?
![brew install mongodb fail bad substitution brew install mongodb fail bad substitution](http://www.pangxieke.com/images/2018/10/1540881516290.jpg)
Brew install mongodb fail bad substitution password#
The password was encoded within CSS rules. Of course MD5ing to find unique file, or just unpacking them all and removing duplicate files still worked.