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| import base64, json, time
import os, sys, binascii
from dataclasses import dataclass, asdict
from typing import Dict, Tuple
from secret import KEY, ADMIN_PASSWORD
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
from flask import (
Flask,
render_template,
render_template_string,
request,
redirect,
url_for,
flash,
session,
)
app = Flask(__name__)
app.secret_key = KEY
@dataclass(kw_only=True)
class APPUser:
name: str
password_raw: str
register_time: int
users: Dict[str, APPUser] = {
"admin": APPUser(name="admin", password_raw=ADMIN_PASSWORD, register_time=-1)
}
def validate_cookie(cookie: str) -> bool:
if not cookie:
return False
try:
cookie_encrypted = base64.b64decode(cookie, validate=True)
except binascii.Error:
return False
if len(cookie_encrypted) < 32:
return False
try:
iv, padded = cookie_encrypted[:16], cookie_encrypted[16:]
cipher = AES.new(KEY, AES.MODE_CBC, iv)
cookie_json = cipher.decrypt(padded)
except ValueError:
return False
try:
_ = json.loads(cookie_json)
except Exception:
return False
return True
def parse_cookie(cookie: str) -> Tuple[bool, str]:
if not cookie:
return False, ""
try:
cookie_encrypted = base64.b64decode(cookie, validate=True)
except binascii.Error:
return False, ""
if len(cookie_encrypted) < 32:
return False, ""
try:
iv, padded = cookie_encrypted[:16], cookie_encrypted[16:]
cipher = AES.new(KEY, AES.MODE_CBC, iv)
decrypted = cipher.decrypt(padded)
cookie_json_bytes = unpad(decrypted, 16)
cookie_json = cookie_json_bytes.decode()
except ValueError:
return False, ""
try:
cookie_dict = json.loads(cookie_json)
except Exception:
return False, ""
return True, cookie_dict.get("name")
def generate_cookie(user: APPUser) -> str:
cookie_dict = asdict(user)
cookie_json = json.dumps(cookie_dict)
cookie_json_bytes = cookie_json.encode()
iv = os.urandom(16)
padded = pad(cookie_json_bytes, 16)
cipher = AES.new(KEY, AES.MODE_CBC, iv)
encrypted = cipher.encrypt(padded)
return base64.b64encode(iv + encrypted).decode()
@app.route("/")
def index():
if validate_cookie(request.cookies.get("jwbcookie")):
return redirect(url_for("home"))
return redirect(url_for("login"))
@app.route("/register", methods=["GET", "POST"])
def register():
if request.method == "POST":
user_name = request.form["username"]
password = request.form["password"]
if user_name in users:
flash("Username already exists!", "danger")
else:
users[user_name] = APPUser(
name=user_name, password_raw=password, register_time=int(time.time())
)
flash("Registration successful! Please login.", "success")
return redirect(url_for("login"))
return render_template("register.html")
@app.route("/login", methods=["GET", "POST"])
def login():
if request.method == "POST":
username = request.form["username"]
password = request.form["password"]
if username in users and users[username].password_raw == password:
resp = redirect(url_for("home"))
resp.set_cookie("jwbcookie", generate_cookie(users[username]))
return resp
else:
flash("Invalid credentials. Please try again.", "danger")
return render_template("login.html")
@app.route("/home")
def home():
valid, current_username = parse_cookie(request.cookies.get("jwbcookie"))
if not valid or not current_username:
return redirect(url_for("logout"))
user_profile = users.get(current_username)
if not user_profile:
return redirect(url_for("logout"))
if current_username == "admin":
payload = request.args.get("payload")
html_template = """
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Home</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<link rel="stylesheet" href="{{ url_for('static', filename='styles.css') }}">
</head>
<body>
<div class="container">
<h2 class="text-center">Welcome, %s !</h2>
<div class="text-center">
Your payload: %s
</div>
<img src="{{ url_for('static', filename='interesting.jpeg') }}" alt="Embedded Image">
<div class="text-center">
<a href="/logout" class="btn btn-danger">Logout</a>
</div>
</div>
</body>
</html>
""" % (
current_username,
payload,
)
else:
html_template = (
"""
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Home</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<link rel="stylesheet" href="{{ url_for('static', filename='styles.css') }}">
</head>
<body>
<div class="container">
<h2 class="text-center">server code (encoded)</h2>
<div class="text-center" style="word-break:break-all;">
{%% raw %%}
%s
{%% endraw %%}
</div>
<div class="text-center">
<a href="/logout" class="btn btn-danger">Logout</a>
</div>
</div>
</body>
</html>
"""
% base64.b64encode(open(__file__, "rb").read()).decode()
)
return render_template_string(html_template)
@app.route("/logout")
def logout():
resp = redirect(url_for("login"))
resp.delete_cookie("jwbcookie")
return resp
if __name__ == "__main__":
app.run()
|