Robot Talk

This server only gives the flag to bots. You'll need to convince it that you're a bot by answering it's challenges.

challenges.neverlanctf.com:1120

Recon

When connecting to the port it asks us to decrypt a base64 string, which is timed so some programming is required.

# nc challenges.neverlanctf.com 1120
Welcome to the NeverLAN CTF.
You have 10 seconds to answer these questions.
decrypt: bnRjcW9samV4Yw==randomstring
That's not it. Restart!
decrypt: YmRtZmF4cndzdQ==

Code

from pwn import *
from base64 import b64decode

s = remote("challenges.neverlanctf.com", 1120)

for i in range(5):
    print s.recvuntil("decrypt: ")
    data = s.recvuntil("==")
    s.send(b64decode(data))

print s.recvall()

Running it:

$ python solve.py 
[+] Opening connection to challenges.neverlanctf.com on port 1120: Done
Welcome to the NeverLAN CTF.
You have 10 seconds to answer these questions.
decrypt: 
=Awesome, continuing.
decrypt: 
=Awesome, continuing.
decrypt: 
=Awesome, continuing.
decrypt: 
=Awesome, continuing.
decrypt: 
[+] Receiving all data: Done (38B)
[*] Closed connection to challenges.neverlanctf.com port 1120
=Awesome, continuing.
flag{Ant1_hum4n}

Flag

flag{Ant1_hum4n}