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KeygenMe #1

append delete fjlj

Video
https://youtu.be/p93zU3XIaO0

Description
Today we will make a pretty basic KeygenMe Challenge program in some very poorly written c++ as it has been ages and most of this will likely be some very ugly code and some reading up on c++ :)

Downloads
Keyme: https://give.academy/KeygenMe1.exe

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Replies

append delete #1. fjlj

I did have to fix a small bug in the exe.. the file has been replaced on the upload server.. if you have already downloaded it.. please re-download the new copy.. :)

append delete #2. catfive

gj :)

append delete #3. fjlj

So in the first Follow Up video

We analyzed the following assembly code.
https://imgur.com/cOQ66C9

and we were able to recreate a javascript version of the first function in our key generation.

% JS
function mkey(input){
	let lookup = "5612307894AFSEGDIVMCPY";
	let sum = 0;
	let pos = -1;
	let stored = [];

	for(let x of input){
	  pos = lookup.indexOf(x);
	  if(pos == -1) pos = 0x12;
	  sum+=pos;
	  stored.push((pos > 9) ? pos + 0x37 : pos + 0x30);
	}

	console.log(String.fromCharCode(...stored));
	//TBC
}
%

tune in next week for more, share your progress here! :)

:: @fjlj added on 04 May ’19 · 09:22

Video #1 Link
https://youtu.be/0D-ZSfl9EVo

Kinda forgot to include it... :)

Your friendly neighbourhood moderators: fjlj, catfive, Radical Raccoon