added basic web based messaging server

messaging-app/Dockerfile

+# Use a minimal Python image
+FROM python:3.9-slim
+
+# Create a non-root user (optional)
+#RUN useradd -m appuser
+
+# Set the working directory
+WORKDIR /app
+
+# Copy the necessary files
+COPY ./app /app
+COPY requirements.txt /app
+
+# Install dependencies
+RUN pip install -r requirements.txt
+
+# Switch to non-root user (optional)
+#USER appuser
+
+# Expose the port the app runs on
+EXPOSE 5000
+
+# Start the Flask app
+CMD ["python", "app.py"]

messaging-app/app/app.py

+from flask import Flask, request, redirect, url_for, render_template, flash, send_from_directory
+from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user
+import os
+
+# Flask app setup
+app = Flask(__name__, template_folder='templates', static_folder='static')
+app.config['UPLOAD_FOLDER'] = './uploads'
+app.secret_key = 'supersecretkey'
+
+# Ensure the uploads directory exists
+if not os.path.exists(app.config['UPLOAD_FOLDER']):
+    os.makedirs(app.config['UPLOAD_FOLDER'])
+
+# In-memory user data (for demonstration purposes)
+users = {}
+messages = {}
+
+# Flask-Login setup
+login_manager = LoginManager()
+login_manager.init_app(app)
+login_manager.login_view = 'login'
+
+# User class
+class User(UserMixin):
+    def __init__(self, id, username, password):
+        self.id = id
+        self.username = username
+        self.password = password
+
+# Load user function for Flask-Login
+@login_manager.user_loader
+def load_user(user_id):
+    for username, user in users.items():
+        if user['id'] == int(user_id):
+            return User(user['id'], username, user['password'])
+    return None
+
+# Home page
+@app.route('/')
+def index():
+    return render_template('index.html')
+
+# Register page
+@app.route('/register', methods=['GET', 'POST'])
+def register():
+    if request.method == 'POST':
+        username = request.form.get('username')
+        password = request.form.get('password')
+        if username in users:
+            flash('Username already exists', 'register-danger')
+        else:
+            user_id = len(users) + 1
+            users[username] = {'id': user_id, 'password': password}
+            flash('Registration successful!', 'login-success')
+            return redirect(url_for('login'))
+    return render_template('register.html')
+
+# Login page
+@app.route('/login', methods=['GET', 'POST'])
+def login():
+    if request.method == 'POST':
+        username = request.form.get('username')
+        password = request.form.get('password')
+        if username in users and users[username]['password'] == password:
+            user = User(users[username]['id'], username, password)
+            login_user(user)
+            flash('Login successful!', 'login-success')
+            return redirect(url_for('index'))
+        else:
+            flash('Invalid username or password', 'login-danger')
+    return render_template('login.html')
+
+# Logout
+@app.route('/logout')
+@login_required
+def logout():
+    logout_user()
+    flash('You have been logged out.', 'login-info')
+    return redirect(url_for('login'))
+
+# Send message
+@app.route('/message', methods=['POST', 'GET'])
+@login_required
+def send_message():
+    if request.method == 'POST':
+        sender = current_user.username
+        recipient = request.form.get('recipient')
+        message = request.form.get('message')
+        if recipient in users:
+            messages[recipient].append({'from': sender, 'message': message})
+            flash('Message sent!', 'message-success')
+        else:
+            flash('Recipient not found', 'message-danger')
+        return redirect(url_for('index'))
+
+    return render_template('send_message.html')
+
+
+
+@app.route('/send_file', methods=['GET', 'POST'])
+@login_required
+def send_file():
+    if request.method == 'POST':
+        recipient = request.form.get('recipient')
+        if recipient not in users:
+            flash('Recipient not found', 'file-danger')
+            return redirect(url_for('send_file'))
+        if 'file' not in request.files:
+            flash('No file part', 'file-danger')
+            return redirect(url_for('send_file'))
+        file = request.files['file']
+        if file.filename == '':
+            flash('No selected file', 'file-danger')
+            return redirect(url_for('send_file'))
+        file_path = os.path.join(app.config['UPLOAD_FOLDER'], file.filename)
+        file.save(file_path)
+        messages[recipient].append({'from': 'send_file', 'message': f'File uploaded: {file.filename}'})
+        flash(f'File {file.filename} uploaded and sent to {recipient}', 'file-success')
+        return redirect(url_for('index'))
+    
+    return render_template('send_file.html')
+
+@app.route('/uploads/<filename>')
+@login_required
+def download_file(filename):
+    return send_from_directory(app.config['UPLOAD_FOLDER'], filename)
+
+if __name__ == '__main__':
+    app.run(host='0.0.0.0', port=5000)

messaging-app/app/templates/base.html

+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <title>{% block title %}Messaging App{% endblock %}</title>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
+  </head>
+  <body>
+    <nav class="navbar navbar-expand-lg navbar-light bg-light">
+      <a class="navbar-brand" href="{{ url_for('index') }}">Messaging App</a>
+      <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
+        <span class="navbar-toggler-icon"></span>
+      </button>
+      <div class="collapse navbar-collapse" id="navbarNav">
+        <ul class="navbar-nav me-auto">
+          <li class="nav-item">
+            <a class="nav-link" href="{{ url_for('index') }}">Home</a>
+          </li>
+          <li class="nav-item">
+            <a class="nav-link" href="{{ url_for('send_file') }}">Send Files</a>
+          </li>
+          <li class="nav-item">
+            <a class="nav-link" href="{{ url_for('send_message') }}">Send Message</a>
+          </li>
+        </ul>
+        <ul class="navbar-nav ms-auto">
+          {% if current_user.is_authenticated %}
+            <li class="nav-item dropdown">
+              <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
+                {{ current_user.username }}
+              </a>
+              <ul class="dropdown-menu dropdown-menu-end" aria-labelledby="navbarDropdown">
+                <li><a class="dropdown-item" href="{{ url_for('logout') }}">Log Out</a></li>
+              </ul>
+            </li>
+          {% else %}
+            <li class="nav-item">
+              <a class="nav-link" href="{{ url_for('login') }}">Log In</a>
+            </li>
+            <li class="nav-item">
+              <a class="nav-link" href="{{ url_for('register') }}">Register</a>
+            </li>
+          {% endif %}
+        </ul>
+      </div>
+    </nav>
+    
+
+    <div class="container mt-4">
+      {% block content %}{% endblock %}
+    </div>
+
+    <!-- Bootstrap JS Bundle with Popper -->
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz" crossorigin="anonymous"></script>
+  </body>
+</html>

messaging-app/app/templates/index.html

+{% extends 'base.html' %}
+{% from "macros.html" import render_flash_messages %}
+{% block title %}Home - Messaging App{% endblock %}
+
+{% block content %}
+<div class="container">
+  <h1>Welcome to the Messaging App</h1>
+  <p class="lead">A simple app to send messages and share files.</p>
+
+  {{ render_flash_messages('login-') }}
+  
+</div>
+{% endblock %}

messaging-app/app/templates/login.html

+{% extends 'base.html' %}
+{% from "macros.html" import render_flash_messages %}
+{% block title %}Login - Messaging App{% endblock %}
+
+{% block content %}
+<div class="container mt-5">
+  {{ render_flash_messages('login-') }}
+  <div class="row justify-content-center">
+    <div class="col-md-6">
+      <h2 class="text-center mb-4">Login</h2>
+
+      <form action="{{ url_for('login') }}" method="post" class="p-4 border rounded shadow-sm">
+        <div class="mb-3">
+          <label for="username" class="form-label">Username</label>
+          <input type="text" name="username" class="form-control" id="username" placeholder="Enter your username" required>
+        </div>
+        <div class="mb-3">
+          <label for="password" class="form-label">Password</label>
+          <input type="password" name="password" class="form-control" id="password" placeholder="Enter your password" required>
+        </div>
+        <button type="submit" class="btn btn-primary w-100">Login</button>
+      </form>
+
+      <div class="text-center mt-3">
+        <a href="{{ url_for('register') }}">Don't have an account? Register</a>
+      </div>
+    </div>
+  </div>
+</div>
+{% endblock %}

messaging-app/app/templates/macros.html

+{# macros.html #}
+{% macro render_flash_messages(category_prefix) %}
+  {% with messages = get_flashed_messages(with_categories=true) %}
+    {% if messages %}
+      {% for category, message in messages %}
+        {% if category.startswith(category_prefix) %}
+          <div class="alert alert-{{ category.split('-')[1] }}">{{ message }}</div>
+        {% endif %}
+      {% endfor %}
+    {% endif %}
+  {% endwith %}
+{% endmacro %}

messaging-app/app/templates/register.html

+{% extends 'base.html' %}
+{% from "macros.html" import render_flash_messages %}
+{% block title %}Register - Messaging App{% endblock %}
+
+{% block content %}
+<div class="container mt-5">
+  {{ render_flash_messages('register-') }}
+  <div class="row justify-content-center">
+    <div class="col-md-6">
+      <h2 class="text-center mb-4">Register</h2>
+
+      <form action="{{ url_for('register') }}" method="post" class="p-4 border rounded shadow-sm">
+        <div class="mb-3">
+          <label for="username" class="form-label">Username</label>
+          <input type="text" name="username" class="form-control" id="username" required>
+        </div>
+        <div class="mb-3">
+          <label for="password" class="form-label">Password</label>
+          <input type="password" name="password" class="form-control" id="password" required>
+        </div>
+        <button type="submit" class="btn btn-primary w-100">Register</button>
+      </form>
+      <div class="text-center mt-3">
+        <a href="{{ url_for('login') }}">Already have an account? Login</a>
+      </div>
+    </div>
+  </div>
+</div>
+{% endblock %}

messaging-app/app/templates/send_file.html

+{% extends 'base.html' %}
+{% from "macros.html" import render_flash_messages %}
+{% block title %}Home - Messaging App{% endblock %}
+
+{% block content %}
+<div class="container">
+  {{ render_flash_messages('file-') }}
+  <h2>Send a File</h2>
+  <form action="{{ url_for('send_file') }}" method="post" enctype="multipart/form-data" class="mb-4">
+    <div class="mb-3">
+      <label for="recipient" class="form-label">Recipient</label>
+      <input type="text" name="recipient" class="form-control" id="recipient" required>
+    </div>
+    <div class="mb-3">
+      <label for="file" class="form-label">Choose file</label>
+      <input type="file" name="file" class="form-control" id="file" required>
+    </div>
+    <button type="submit" class="btn btn-primary">Send File</button>
+  </form>
+
+</div>
+{% endblock %}

messaging-app/app/templates/send_message.html

+{% extends 'base.html' %}
+{% from "macros.html" import render_flash_messages %}
+{% block title %}Home - Messaging App{% endblock %}
+
+{% block content %}
+<div class="container">
+  {{ render_flash_messages('message-') }}
+  <h2>Send a Message</h2>
+  <form action="{{ url_for('send_message') }}" method="post" class="mb-4">
+    <div class="mb-3">
+      <label for="recipient" class="form-label">Recipient</label>
+      <input type="text" name="recipient" class="form-control" id="recipient" required>
+    </div>
+    <div class="mb-3">
+      <label for="message" class="form-label">Message</label>
+      <textarea name="message" class="form-control" id="message" rows="3" required></textarea>
+    </div>
+    <button type="submit" class="btn btn-primary">Send Message</button>
+  </form>
+
+</div>
+{% endblock %}

messaging-app/app/uploads/malicious.sh

+#!/bin/bash
+echo "You've been hacked!\n"
+whoami

messaging-app/docker-compose.yml

+services:
+  web:
+    build: .
+    ports:
+      - "5000:5000"
+    volumes:
+      - ./app/uploads:/app/uploads

messaging-app/malicious.sh

+#!/bin/bash
+echo "You've been hacked!\n"
+whoami

messaging-app/requirements.txt

+Flask==2.2.5
+Werkzeug==2.2.3
+flask-login
\ No newline at end of file