picoCTF2018

This challenge is the same with challenge keygen me 1. It is just different at validate_key() function. Put it in to IDA pro , after find to validate_key() function. We have like this

Key will thought 12 function to check correct key . key_constraint_01()

key_constraint_02()

All function next the same with function 1 and 2. so I don’t show it at here. I will solve it with Z3. I writed a script to solve : The result: