requirements.txt

cycler==0.10.0
kiwisolver==1.3.1
matplotlib==3.3.4
numpy==1.19.5
Pillow==8.2.0
pyparsing==2.4.7
python-dateutil==2.8.1
six==1.16.0

stenography-ctf.py

import zipfile, argparse, os, shutil
import matplotlib.pyplot as plt
import numpy as np 

parser = argparse.ArgumentParser(description="Steno ctf")
parser.add_argument('--image', required=True, help='path to image')

args = parser.parse_args()
src_dir = os.getcwd()
src = os.path.join(src_dir, args.image)
dest = os.path.join(src_dir, args.image + '.zip')
shutil.copy(src, dest)

with zipfile.ZipFile(dest, "r") as ref:
    ref.extractall(src_dir)

coord = np.genfromtxt('./paint_it_black.txt', delimiter=',')

out = np.zeros(shape=(90,90))
x, y = coord.T[0], coord.T[-1]

plt.scatter(x, y)
plt.savefig(os.path.join(src_dir, 'pass.jpeg'))

print("""
Read pass.jpeg for the password to unzip flag.zip

```
unzip flag.zip
```
""")

p = input("Enter password: ")
with zipfile.ZipFile(os.path.join(src_dir, "flag.zip")) as ref:
    ref.extractall(src_dir, pwd=bytes(p, 'utf-8'))

with open('flag.txt', 'r') as f:
    content = f.read()
    print("content: {}".format(content))

# Cleanup
os.unlink('./flag.txt')
os.unlink('./flag.zip')
os.unlink('./pass.jpeg')
os.unlink('./paint_it_black.txt')
os.unlink(dest)