How to make a simple HTTPS server in Python 3x

How to Make a Simple HTTPS Server in Python 3.x

Learn to set up a basic HTTPS server using Python's http.server and ssl modules. This guide covers certificate generation, server configuration, and secure request handling.

Establishing a secure connection is paramount for any web application. HTTPS (Hypertext Transfer Protocol Secure) ensures that data exchanged between a client and a server is encrypted, protecting it from eavesdropping and tampering. This article will guide you through creating a simple HTTPS server in Python 3.x, covering certificate generation, server setup, and basic request handling.

1. Understanding HTTPS and SSL/TLS

Before diving into implementation, it's crucial to understand what HTTPS entails. HTTPS is essentially HTTP over SSL/TLS (Secure Sockets Layer/Transport Layer Security). SSL/TLS provides encryption, authentication, and data integrity. To enable HTTPS, your server needs an SSL/TLS certificate, which proves its identity and facilitates the encryption process. For development and testing, you can use self-signed certificates.

2. Generating Self-Signed SSL Certificates

For a local development server, you don't need a certificate authority (CA) to sign your certificate. You can generate a self-signed certificate and a private key using OpenSSL. These files (typically .crt for the certificate and .key for the private key) are essential for your HTTPS server.

openssl req -new -x509 -days 365 -nodes -out server.crt -keyout server.key

This command generates a new self-signed certificate (server.crt) and a private key (server.key) valid for 365 days.

During the certificate generation, you will be prompted to enter information. For the 'Common Name', use localhost or your server's IP address if you intend to access it from another machine on your local network. The other fields can be filled with arbitrary information.

3. Implementing the HTTPS Server in Python

Python's built-in http.server module provides a basic HTTP server, and the ssl module allows you to wrap a standard socket with SSL/TLS encryption. We will combine these to create our HTTPS server. The process involves creating a custom handler, instantiating the HTTP server, and then wrapping its socket with SSL.

import http.server
import ssl
import socketserver

PORT = 8000
DIRECTORY = "."

class Handler(http.server.SimpleHTTPRequestHandler):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, directory=DIRECTORY, **kwargs)

    def do_GET(self):
        # Example: Log incoming requests
        print(f"Received GET request for: {self.path}")
        super().do_GET()

    def do_POST(self):
        # Example: Handle POST requests
        print(f"Received POST request for: {self.path}")
        content_length = int(self.headers['Content-Length'])
        post_data = self.rfile.read(content_length).decode('utf-8')
        print(f"POST data: {post_data}")

        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        self.wfile.write(b"<h1>POST Request Received!</h1>")

with socketserver.TCPServer(('', PORT), Handler) as httpd:
    httpd.socket = ssl.wrap_socket(httpd.socket, 
                                   keyfile="server.key", 
                                   certfile="server.crt", 
                                   server_side=True)
    print(f"Serving HTTPS on port {PORT}")
    print(f"Access it at https://localhost:{PORT}")
    httpd.serve_forever()

This Python script sets up an HTTPS server using http.server and ssl. It serves files from the current directory and includes basic GET/POST handling.

HTTPS Server Architecture

4. Running and Testing Your HTTPS Server

To run your server, make sure server.crt and server.key are in the same directory as your Python script. Then execute the script from your terminal. Open a web browser and navigate to https://localhost:8000 (or your chosen port). You should see the contents of the directory being served securely.

1. Step 1

Save the Python code above as https_server.py in a directory.

2. Step 2

Place the server.crt and server.key files (generated in Step 2) in the same directory.

3. Step 3

Open your terminal or command prompt, navigate to that directory, and run python https_server.py.

4. Step 4

Open your web browser and go to https://localhost:8000. Accept the security warning to proceed.

You can also test the server with curl:

curl -k https://localhost:8000/

The -k flag tells cURL to bypass SSL certificate validation for self-signed certificates.