HTTPS Server from Scratch in Python

This project implements a minimal HTTPS file server from scratch using Python's socket and ssl modules, without relying on web frameworks such as Flask, Django, or Node.js.

The goal of this project is to understand how secure web servers work at a low level by manually building the network stack integration between TCP, TLS, and HTTP.

The server supports:

• TCP socket creation and connection handling
• TLS encryption using a self-signed certificate
• HTTPS communication with browsers and LAN devices
• Basic HTTP/1.0 request parsing
• Static file serving from a local directory (htdocs/)

This project demonstrates how HTTPS is fundamentally implemented as HTTP over a TLS-encrypted transport layer.

It serves as a foundation for building more advanced systems such as secure APIs, file synchronization services, or lightweight web applications without relying on external frameworks.

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Features

• HTTPS support using TLS (self-signed certificate)
• HTTP/1.0 request handling
• Static file serving from htdocs/
• Works with modern browsers and mobile devices
• No external dependencies (standard library only)

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Purpose

This project was built to understand how HTTPS servers work internally, including TLS handshakes, certificate-based encryption, and HTTP communication over secure sockets.

It avoids using frameworks to expose the underlying mechanics of secure network communication.

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Note

This server requires a self-signed TLS certificate.

Generate one using OpenSSL:

openssl req -x509 -nodes -days 3650 -newkey rsa:2048 \
-keyout key.pem -out cert.pem \
-subj "/CN=localhost"

This creates

cert.pem   # public certificate  
key.pem    # private key

Place them in the root of the project

After generating the cert.pem and key.pem, run the server

Running the Server

Start the server

python3 http_server.py

Then open your browser and navigate to

https://localhost:8443

If accessing from some other device on the same network like phone,

https://<your-local-ip>:8443

Example:

https://192.168.0.5:8443

You may need to accept a security warning since the certificate is self-signed.

Updates (v1.1)

This version focuses on stabilizing and securing the server before adding advanced features.

Fixes & Improvements

• Implemented safe path handling to prevent directory traversal (../) attacks
• Removed global state for folder rendering (preparing for future concurrency support)
• Added proper 404 handling for missing files
• Improved request handling with larger buffer size
• Added MIME type detection for correct file serving
  • Images now render correctly in browser
  • Supports multiple file types (png, jpg, txt, etc.)
• Improved error handling for file access and directory reading
• Cleaned routing logic for /browse and /file

Current Capabilities

• HTTPS server using TLS (self-signed certificate)
• Recursive folder browsing
• Static file serving from vault directory
• Works across devices (laptop + mobile)
• Correct handling of binary and text files

Known Limitations

• Markdown files are currently rendered as plain text
• Obsidian-specific syntax (![[...]], [[...]]) is not yet supported
• No file editing or write functionality
• Single-threaded (no concurrent client handling yet)

Next Steps

• Markdown rendering support
• Obsidian-style embed and link parsing
• Multi-threaded request handling
• JSON API for programmatic access

Updates (v1.3)

This version marks a major transition from a read-only file server to a write-capable web editor.

Remote Editing

The server now supports editing files directly from the browser using a simple HTML interface and HTTP POST requests.

Features Added

• Added /save route for editing files
• Implemented HTML form-based editing interface with <textarea>
• Added POST request handling for writing data to disk
• Enabled file modification over HTTPS from any device on the same network
• Supports appending content to existing files (initial editing model)

Editing Flow

Browse → Open File → Click "Write" → Edit → Save → File Updated

How It Works

• GET /save/<path>
• Renders an editor view with the file content and a textarea POST /save
• Receives form data (content, path) and writes it to disk
• Form submission uses application/x-www-form-urlencoded encoding which is manually parsed from raw socket data

Architectural Shift

This version transforms the system from:

Static Viewer → Interactive Editor

The server is no longer just serving files — it now modifies persistent state, making it a minimal web application.

Current Limitations

• Editing is currently append-only (does not overwrite full file)
• No authentication (anyone on the network can edit files)
• No conflict handling or versioning
• No concurrency (single-threaded)
• No input validation beyond basic path safety

Next Steps

• Full file editing (overwrite instead of append)
• Pre-filled textarea with existing file content
• Redirect after save (improved UX)
• Basic authentication layer
• Improved UI/UX for mobile editing
• Better request parsing (handle large POST bodies)

Project Evolution

This project has evolved from:

Low-level HTTPS server → File browser → Markdown renderer → Obsidian viewer → Web-based editor (current)

The long-term goal is to build a lightweight system similar to Obsidian Sync:

View notes on mobile Edit notes remotely Sync changes directly to local vault via HTTPS No heavy frameworks or external dependencies

Updates (v1.4)

This version completes the transition from a basic append-only editor to a more complete file management system.

Full File Editing

• Added /overwrite route with a dedicated editing view
• Users can now open a file in a full-screen editor and overwrite its contents
• Implemented proper separation of GET (editor UI) and POST (file write) for safer operations
• Fixed HTML injection issues by escaping content before rendering inside <textarea>

New File Creation

• Added /newfile route to create new markdown files directly from the browser
• Automatically appends .md extension if omitted
• Redirects to the overwrite editor after creation for immediate editing
• Prevents overwriting existing files

Improved Request Handling

• Implemented robust POST body parsing using Content-Length
• Added support for large form submissions (full file edits)
• Switched to parse_qs for correct handling of URL-encoded data

File Safety Enhancements

• Prevented accidental writes to directories
• Enforced file validation before overwrite operations
• Strengthened path safety using safe_path

UI Improvements

• Introduced full-screen editing interface for overwrite mode
• Added centered editor layout and improved usability
• Enabled inline file creation UI in leaf folders

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Editing Modes

The system now supports two editing workflows:

• Append Mode (/save) → Quick journaling / incremental updates
• Overwrite Mode (/overwrite) → Full document editing

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Next Steps

• File versioning / history system
• Multi-device sync (core Owl goal)
• Background sync and change detection
• Basic authentication / access control
• Refactoring into modular architecture