HTTPS WebSocket Demo

SSL/TLS WebSocket Demo

A NetBurner application demonstrating secure and non-secure HTTP/HTTPS web server functionality with WebSocket support and SSL/TLS authentication.

Overview

This application showcases how to implement both secure (HTTPS) and non-secure (HTTP) access to web resources alongside WebSocket communication. The server provides different access levels based on connection security, demonstrating practical SSL/TLS authentication patterns.

Features

• Dual Protocol Support: Serves content over both HTTP (port 80) and HTTPS (port 443)
• SSL/TLS WebSocket: Secure WebSocket communication with authentication
• Access Control: Directory-based security with SSL-only restricted areas
• Dynamic Content: Server-side functions for generating dynamic links and content
• Echo WebSocket: Real-time bidirectional communication demonstration

Directory Structure

html/
      httpsdir/
            ssl.html          # HTTPS-only accessible content
      images/
            SSL-Good.gif      # Shown for secure connections
            SSL-Bad.gif       # Shown for non-secure connections
      index.html              # Main page (HTTP/HTTPS accessible)
      script.js               # Client-side JavaScript

Access Control

The application implements a three-tier access control system:

• Level 0: Public access (HTTP/HTTPS)
• Level 1: HTTPS-only access
• Higher Levels: Custom authentication (extensible)

Security Implementation

HTTP_ACCESS CheckHttpAccess(int sock, int access_level, HTTP_Request &Req)

This function overrides the system default to enforce SSL/TLS requirements:

• Level 0: Always accessible
• Level 1: Requires SSL connection, returns HTTP_FORBIDDEN for non-SSL
• Extensible for additional security levels

WebSocket Functionality

Echo WebSocket Endpoint

• Endpoint: /echo*
• Functionality: Echoes received messages back to sender
• Protocol: Supports both WS and WSS (secure WebSocket)

WebSocket Lifecycle

1. Connection established via WSStart() callback
2. Socket registered and semaphore posted
3. Main loop handles read/write operations
4. Automatic cleanup on connection errors

Dynamic Content Functions

SSL_Image()

Dynamically serves different images based on connection security:

• SSL connections: SSL-Good.gif
• Non-SSL connections: SSL-Bad.gif

HTTPS_Ref() / HTTP_Ref()

Generates protocol-specific URLs for navigation:

• Automatically detects host information
• Constructs proper HTTPS/HTTP links
• Supports both hostname and IP address formats

Host_Ref()

Provides the current host identifier (hostname or IP address)

Configuration Options

Default Configuration

StartHttps();  // Starts both HTTP (80) and HTTPS (443)

HTTPS-Only Configuration

StartHttps(443, 0);  // HTTPS only, disables HTTP port

Network Requirements

• DHCP: Waits up to 5 seconds for network address assignment
• Ports:
  • HTTP: 80 (configurable/disableable)
  • HTTPS: 443 (configurable)
• SSL/TLS: Requires valid SSL certificate configuration

Main Application Flow

1. Initialization
   • Network stack initialization
   • System diagnostics enablement
   • DHCP address acquisition
2. Server Startup
   • HTTP/HTTPS web server activation
   • WebSocket endpoint registration
3. Main Loop
   • WebSocket connection monitoring
   • Bidirectional data handling
   • Error detection and cleanup
   • Connection state management

Development Notes

Memory Management

• Uses SMPoolPtr for buffer management
• ETHER_BUFFER_SIZE defines maximum message size
• Automatic cleanup on connection errors

Concurrency

• Uses OS_SEM semaphore for WebSocket synchronization
• select() for non-blocking I/O operations
• Proper file descriptor management

Error Handling

• Connection error detection via select()
• Graceful socket closure
• Automatic reconnection support

Security Considerations

1. SSL/TLS Configuration: Ensure proper certificate installation
2. Access Control: Directory-based restrictions prevent unauthorized access
3. Connection Validation: All SSL connections verified before serving content
4. Resource Protection: Sensitive content isolated in httpsdir/

Usage Instructions

1. Build and Deploy: Compile with NetBurner development tools
2. Network Setup: Ensure device has network connectivity
3. Access: Navigate to device IP address via web browser
4. Test Security: Compare HTTP vs HTTPS access to different resources
5. WebSocket: Use JavaScript client to connect to echo endpoint

Troubleshooting

• Connection Issues: Check network configuration and DHCP
• SSL Errors: Verify certificate installation and validity
• Access Denied: Ensure proper file placement in directory structure
• WebSocket Failures: Monitor console output for connection status