I’ve found both parts of the code that creates the “serial number” but can’t wrap my head around it how the code works. Tried with an array of 0123456789abc (same length as the part before the -) to see how the User name rotates… it does not make sense when I compare it to the code.
Hints are welcome
@Tazdevl said:
I’ve found both parts of the code that creates the “serial number” but can’t wrap my head around it how the code works. Tried with an array of 0123456789abc (same length as the part before the -) to see how the User name rotates… it does not make sense when I compare it to the code.Hints are welcome
You don’t necessarily have to understand the sourcecode to full extend for this challenge. But chosing the username is a good idea to solve it - check the output and make your conclusions from that.
Found the date half. The username part still doesn’t make sense when I reverse it on paper.
new action plan, I solved it… turns out I was heading in the wrong direction (encrypting it again instead of reversing)
Solved this in about 15 minutes. Didn’t even look at the code. Easy to work it out on paper by mapping the username and by guessing the number of days for the license.
@PenTestPumpkin said:
Solved this in about 15 minutes. Didn’t even look at the code. Easy to work it out on paper by mapping the username and by guessing the number of days for the license.
THIS. Trying to reverse the code directly was making my brain hurt. Solved.
i solved it in only 5+15 mins just get a pen and a paper easy 
I solved this one by brute forcing it, but I dont think that this is elegant enough.
If someone with skills on C# programming could send me the way the code wil be to revert the key I would be glad!!
Thanks in advance
I also wanted to reverse the algorithm for the username, but doing it on paper was much easier…
nice one:)