3lioo

hi there  in this article i'll tell you how i solved the rev me easy  challenge in can-cwic ctf 2017,so let's go first the challenge look like the image below   after downloading the file  Let’s take a look at the binary in IDA    so as we saw it is pretty simple  it is just move group of values one by one to edx then xor it with the value in eax  now what is the value in eax  let's scroll up a little bit and we found it it is 0x10 so after i collect all the values that been mov to edx and xored  in order to solve the challenge i wrote a python script that do  the same operation the app do and print the result  wish supposed to be the flag cc = "" bb = [] aa = [ 0x56 , 0x5c , 0x51 , 0x57 , 0x6b , 0x42 , 0x23 , 0x66 , 0x75 , 0x62 , 0x63 , 0x79 , 0x7e , 0x77 , 0x4f , 0x79 , 0x25 , 0x4f , 0x7e , 0x20 , 0x64 , 0x4f , 0x64 , 0x78 , 0x71 , 0x64 , 0x4f , 0x78 , 0x71 , 0x6...