ker2x on 4:39 PM 06/24/2019: it's my first time trying a C++ challenge, it's a real pain. and even ghidra thrown an error. i can't solve it yet :(
x0r19x91 on 10:51 AM 06/25/2019: The sha512 of the solution is b9d9c8b32a89a7152562b586654663459865784d7a75302b695cb2aabd9eb4b7bfcad9452e611e24748d4c3ba5f1306ef4f456a0d6f3d97a159dc6cfe7ce748e
SYS_V on 3:19 PM 06/25/2019: ghidra threw an error when I was looking at the function graph for decrypt (I think. Can't remember which function exactly, haven't tried to replicate it yet). Don't know if it's the same error ker2x encountered.