NetBurner 3.5.8
PDF Version
SecureSerToEthFactoryApp

Example Path: examples/SSH/SecureSerToEthFactoryApp

NetBurner Secure Serial-to-Ethernet Factory Application

Overview

The NetBurner Secure Serial-to-Ethernet Factory Application is a comprehensive embedded application that provides secure bi-directional communication between serial interfaces and Ethernet networks. This application is pre-programmed into NetBurner Serial-to-Ethernet devices and serves as a bridge between various serial protocols and network connectivity. The application pre-programmed into NetBurner Serial to Ethernet devices. This application source code is provided for customers that wish to customize the application.

Interfaces:

  • RS-232
  • RS-422
  • RS-485
  • CAN Bus
  • I2C
  • Ethernet
  • Wifi
Note
Please refer to the Secure Serial Factory App Users Manual for a detailed description of this application at www.netburner.com.

Application Architecture

Entry Point

The application starts in UserMain() (located in src/main.cpp), which is the standard entry point for all NetBurner applications, rather than the typical C/C++ main() function.

Core Features

Multi-Protocol Support:**

  • TCP/IP communication
  • UDP communication
  • SSH (Secure Shell) connections
  • TLS/SSL encrypted connections

  • Multiple serial interface protocols (RS-232, RS-485, CAN Bus, I2C)

    Network Capabilities:**

  • DHCP and static IP addressing
  • WiFi connectivity support
  • Network Time Protocol (NTP) synchronization
  • DNS resolution

  • HTTPS web server interface

    Security Features:**

  • SSL/TLS encryption for secure data transfer
  • SSH authentication and key management
  • Certificate and key management system
  • Configurable user authentication

Supported Hardware Platforms

  • SBE70LC - NetBurner SBE70LC modules
  • SB800EX - NetBurner SB800EX modules
  • NANO54415 - NetBurner NANO54415 modules
  • MODM7AE70 - NetBurner MODM7AE70 modules
  • SOMRT1061 - NetBurner SOMRT1061 modules
  • MOD5441X - NetBurner MOD5441X modules

Key Source Files

Main Application

  • src/main.cpp - Main application entry point and core logic
  • src/nbfactory.h - Factory configuration definitions and platform-specific settings

Serial Communication

  • src/serialrecord.cpp/h - Core serial port management and data handling
  • src/serialburnerdata.h - Serial port configuration structures
  • src/atparserforssh.cpp - AT command parser for SSH configuration

Network & Security

  • src/sshuser.cpp/h - SSH user authentication and key management
  • src/ssluser.cpp/h - SSL/TLS user authentication
  • src/certificatekey.cpp - Certificate and key management
  • src/ServerKey.cpp - Server key handling
  • src/ServerCert.cpp - Server certificate handling

Hardware Interface

  • src/gpioserver.cpp/h - GPIO server for pin control
  • src/i2cserver.cpp/h - I2C server implementation
  • src/i2cfuncs.cpp/h - I2C utility functions
  • src/analog.cpp/h - Analog input handling

Web Interface

  • src/configweb.cpp - Web-based configuration interface
  • src/configweb_wifi.cpp - WiFi-specific web configuration
  • src/formtools.cpp/h - HTML form processing utilities
  • src/post.cpp - HTTP POST request handling

File System & Storage

  • src/effs_std.cpp/h - EFFS (Embedded Flash File System) STD implementation
  • src/effsStdPartition.cpp - Flash partition management
  • src/FileSystemUtils.cpp/h - File system utility functions
  • src/ftp_fs.cpp/h - FTP file system interface

System Utilities

  • src/fdtimer.cpp/h - File descriptor timer management
  • src/fnbrtosdump.cpp - RTOS debugging and diagnostics
  • src/autoupdate.cpp - Remote firmware update functionality

Configuration and Web Interface

The application includes a comprehensive web-based configuration interface with the following pages:

Network Configuration

  • html/network.html - Main network settings
  • html/tcp.html - TCP protocol configuration
  • html/udp.html - UDP protocol configuration
  • html/wifi.html - WiFi connectivity settings

Security Configuration

  • html/ssh.html - SSH server configuration
  • html/ssl.html - SSL/TLS settings
  • html/certificate.html - Certificate management
  • html/keys.html - Cryptographic key management

Serial Port Configuration

  • html/serial.html - Serial port settings
  • html/advancedserial.html - Advanced serial configuration
  • html/i2c.html - I2C interface settings

System Management

  • html/advanced.html - Advanced system settings
  • html/gpio.html - GPIO pin configuration
  • html/password.html - User authentication settings

Build Configuration

Makefile Structure

The project uses a standardized NetBurner makefile with the following key components:

  • Target Name: SecureSerToEthFactoryApp
  • Supported Platforms: All major NetBurner platforms
  • Dependencies: EFFS STD file system library
  • Generated Files: HTML content is compiled into src/htmldata.cpp

Memory Configuration

Platform-specific memory settings:

  • MOD5441X/NANO54415/SB800EX: 1MB reserved for EFFS STD file system
  • MODM7AE70/SBE70LC: Application memory relocation disabled

Key Features Implementation

Data Flow Management

The SerialRecord class manages bidirectional data flow between serial ports and network connections, implementing:

  • Circular buffering for serial-to-network and network-to-serial data
  • Connection state management
  • Timeout handling
  • Keep-alive functionality

Protocol Handling

The application supports multiple connection modes:

  • Server Mode: Listens for incoming connections
  • Client Mode: Initiates outbound connections
  • UDP Mode: Connectionless datagram communication
  • SSH Mode: Secure shell connections with authentication

Security Implementation

  • Certificate and key management with support for RSA and ECDSA
  • SSL/TLS encryption for web interface and data connections
  • SSH authentication with public key support
  • Configurable user credentials and access control

Configuration Methods

The device can be configured through multiple interfaces:

  1. Web Interface (HTTP/HTTPS) - Full-featured browser-based configuration
  2. Configuration Interface - NetBurner's standard configuration protocol
  3. AT Commands - Serial port based command interface
  4. Remote Updates - Over-the-air firmware updates

Development and Customization

This source code is provided to enable customers to customize the factory application for specific requirements. Key customization points include:

  • Protocol Extensions: Add support for custom protocols
  • Hardware Integration: Interface with specific sensors or actuators
  • Security Policies: Implement custom authentication mechanisms
  • Data Processing: Add filtering, transformation, or logging capabilities

System Requirements

  • NetBurner development environment with SDK
  • Compatible NetBurner hardware platform
  • Network connectivity for web-based configuration
  • Optional: WiFi module for wireless connectivity

Additional Resources

For detailed documentation and user manuals, visit www.netburner.com and refer to the Secure Serial Factory App Users Manual.