TAMU CTF 2022 Writeup — Reversing: Covfefe

Unpacking the archive provided by this challenge yielded a text file containing some Java code. Examining the code, its doing a lot of math and confusing stuff with numbers but it’s pretty clear that the entire purpose of the object is to construct an array object called arrayOfInt. Moreover, each integer that looks supsiciously like an ASCII byte. Adding the following to the bottome of the file modifies the code to print the array object:

With this change in place, we can compile the code and execute it from the terminal with:

javac Covfefe.java && java Covfefe

All that remained was to convert the ASCII byte codes to characters by mapping to the ASCII table: gigem{c0ff33_1s_4lw4ys_g00d_0xCUPS}.