BitsnBytes

(No description)

https://challenges.neverlanctf.com:1150

Recon

The URL loads an SVG image from: https://challenges.neverlanctf.com:1150/svg.php

This contains an image with colored blocks, but only two colors are used. Combining the colors as bits gives us a bit stream which can be decoded to ascii.

Code

import requests
import re

s = requests.Session()

url = "https://challenges.neverlanctf.com:1150/svg.php"
data = s.get(url).content
fills = re.findall(r'fill:.......', data)
colors = ""
for fill in fills:
    if "0" in fill:
        colors += "0"
    else:
        colors += "1"

arr_bytes = [colors[i:i+8] for i in range(0, len(colors), 8)]

out = ""
for i in arr_bytes:
    out += chr(int(i,2))

print out

$ python bitsnbytes.py 
Now you've got it! Here's your flag: flag{its_all_ab0ut_timing}

After running it for some time, it seems that around the 24th, 25th minute every hour you will get the flag.

Flag

flag{its_all_ab0ut_timing}