Baby

As I learn about reverse engineering and hacking, I find myself repeating certain
steps. When working on the network, I start with Nmap and when reverse engineering
I start with file.

file baby | tr "," "\n"

The next thing I did was execute the file.

$ ./baby     
Insert key:

This is interesting and something to keep in mind as I look through the code.

I opened the file in ghidra and looked at the code. I found a function named main
and started there.

The first section is declaring variables and nothing too interesting. I see a
puts function call that asks for a key and a fgets that looks to assign standard
input to one of the variables. Next, strcmp looks like a string comparison from
what I can tell and the value is assigned and compared in the if statement.
It looks like if the input from the user matches abcde122313\n then something
is printed to the console with the puts function. If it is not equal to abcde122313\n
than puts prints out Try again later. and exits.

Well, alright then lets give it a shot. Lets execute the file and inter abcde122313
as the key.

./baby
Insert key:
abcde122313
HTB{B4BY_R3V_TH4TS_EZ}

That's it! We got the flag!

Download baby and try it yourself.