In this CTF, I had only solved first chall of rev.
Chugga chugga
- This chall is too long for lazy guy like me to do. I have admitted that I just only solve this chall 8 hours till the CTF end.
- As usual, I open it on IDA and look for string, can't find anything there. Next, look at the fucntion name, I had main_main, main_win.
- Look at main_win and follow the string, I see the congratulation!
- So that, come back to main_main and find the condition.
- Follow back from main_win, I can make a breakpoint to notice the trace of true condition.
- At the begin, after receive an input from fmt_Fscam, the input is stored at [rsp+0A8h+INPUT]
- rdx take the input, rcx stored the length of input (rdx and rcx could be changed).
- Our mission is rebuild a condition by following, change the input and solve the Simul Equation.
