#Sekai_CTF_2022
from io import BytesIO
from PIL import Image
from flask import Flask, request, render_template
import base64
app = Flask(__name__, template_folder="")
app.config['MAX_CONTENT_LENGTH'] = 2 * 1000 * 1000
FLAG_PATH = "flag.png"
flag_img = Image.open(FLAG_PATH)
def encrypt_img(img: Image) -> Image:
pass
def img_to_data_url(img: Image) -> str:
f = BytesIO()
img.save(f, format="PNG")
img_base64 = base64.b64encode(f.getvalue()).decode("utf-8")
return f"data:image/png;base64,{img_base64}"
@app.route("/")
def index():
return render_template("index.html")
@app.route("/upload", methods=["POST"])
def upload():
pass
if "image" not in request.files:
return "Image not found", 403
files = request.files.getlist('image')
imgs = []
for file in files:
try:
im = Image.open(file.stream)
except Exception as e:
return "Invalid image", 403
if im.format != "PNG":
return "Invalid image format: Please upload PNG files", 403
if im.size[0] > 256 or im.size[1] > 256:
return "Image too large: Maximum allowed size is 256x256", 403
im = im.convert('L')
imgs.append(im)
imgs.append(flag_img)
try:
urls = [img_to_data_url(encrypt_img(im)) for im in imgs]
except Exception as e:
return "I don't know how but black magic is detected", 403
return render_template("upload.html", url1=urls[0], url2=urls[1], url3=urls[2])
if __name__ == "__main__":
app.run(debug=False)
