I recently found more wargames at overthewire.org. Here are my hints and solutions for the first three levels of Vortex. The levels are cumulative. We have to beat the previous level in order to access the next.
Vortex Level 0 -> Level 1
Hint 1: how much data
Connect to the host and port and read all the bytes you can. How many bytes do you get?
Hint 2: endianess
“…read in 4 unsigned integers in host byte order” means the bytes are
already in host byte order or little-endian. If your system is also
little-endian, you don’t need to do anything special when interpreting the
bytes.
Hint 3: expected reply
How many bytes is each integer? What is the sum of all four?