EDHOC Examples

This directory contains simple examples demonstrating how to use the EDHOC (Ephemeral Diffie-Hellman Over COSE) implementation in Contiki-NG.

EDHOC is a lightweight authenticated key exchange protocol described in RFC 9528.

Directory Structure

  • edhoc-client/ - Simple EDHOC client example (Initiator)

  • edhoc-server/ - Simple EDHOC server example (Responder)

Quick Start

Building the Examples

EDHOC Server

cd examples/edhoc/edhoc-server
make TARGET=native

EDHOC Client

cd examples/edhoc/edhoc-client
make TARGET=native

Running the Examples

Native Platform

  1. Start the server:

    cd examples/edhoc/edhoc-server
./edhoc-server-example.native

  2. Start the client (in another terminal):

    cd examples/edhoc/edhoc-client
./edhoc-client-example.native

Cooja Simulation

Run the interactive demo simulation:

cd examples/edhoc
make COOJA_ARGS="--no-gui" edhoc-demo.csc

For interactive mode (with GUI):

cd examples/edhoc
make edhoc-demo.csc

Configuration

Server Configuration

Edit edhoc-server/project-conf.h to customize:

  • Server identity: EDHOC_AUTH_KID (or EDHOC_AUTH_SUBJECT_NAME)

  • Logging levels

  • CoAP and network parameters

Client Configuration

Edit edhoc-client/project-conf.h to customize:

  • Server endpoint: EDHOC_CONF_SERVER_EP

  • Logging levels

  • CoAP and network parameters

EDHOC Protocol Flow

  1. Client (Initiator) sends MSG_1 to /.well-known/edhoc

  2. Server (Responder) responds with MSG_2

  3. Client sends MSG_3 to complete the handshake

  4. Secure communication can now proceed using derived keys

Advanced Usage

For more comprehensive testing and advanced features, see the test suite in:

  • tests/21-security-protocols/

The test suite includes:

  • Multi-method support (Method 0, Method 3)

  • Comprehensive error handling

  • Network simulation with Cooja

  • Performance benchmarks

Supported Platforms

  • Native (Linux/macOS) - for development and testing

  • CC2538DK - Texas Instruments platform

  • Zoul - IoT platform

  • Other Contiki-NG supported platforms

Security Considerations

These examples use default keys and configuration suitable for testing. For production use:

  1. Generate unique keys for each device

  2. Implement proper key storage (secure elements, etc.)

  3. Configure appropriate cipher suites for your security requirements

  4. Enable proper authentication and authorization mechanisms

Troubleshooting

Common Issues

  1. Network connectivity: Ensure both client and server can reach each other

  2. Key mismatch: Verify both sides use compatible keys and cipher suites

  3. CoAP issues: Check CoAP configuration and endpoint addresses

Debug Logging

Enable debug logging by modifying the log levels in project-conf.h:

#define LOG_CONF_LEVEL_EDHOC        LOG_LEVEL_DBG
#define LOG_CONF_LEVEL_COAP         LOG_LEVEL_DBG

Further Reading