ECC608 Crypto Chip: Self-signed Certificate

Introduction

Creating a self-signed certificate using the ECC608 crypto chip involves generating a private key within the chip and then creating a certificate that is signed with this key. This tutorial demonstrates the process using CONTROLLINO MICRO and the ECC608 chip.

Prerequisites

• Installed Arduino IDE.
• CONTROLLINO MICRO board.

Example Code

Please grab the following example .ino file from Github:

Step-by-Step Guide

Step 1: Setup the Arduino Environment

1. Connect your MICRO to your computer.
2. Open the Arduino IDE.
3. Ensure that the appropriate board and port are selected in the Tools menu.

Step 2: Understanding the Provided Code

The provided example code performs the following functions:

• Initializes the ECC608 chip.
• Checks if the chip is locked and prompts the user to lock it with a default TLS configuration if not.
• Gathers input for certificate details such as issue date, expiry, and slot numbers for key storage.
• Generates a new private key (if required) and a self-signed certificate.
• Outputs the certificate and its SHA1 fingerprint.

Step 3: Load the Example Code

1. Copy the provided code into a new sketch in the Arduino IDE.
2. Review the code to understand its flow and functionality.

Step 4: Modify the Code (Optional)

You can modify the default values or add additional functionality as needed. For instance, you might want to change the default slot numbers or the default years of validity for the certificate.

Step 5: Compile and Upload the Code

1. Click on the Verify button to compile the code.
2. Click on the Upload button to upload the code to your Arduino MKR board.

Step 6: Interact with the Program

After uploading, open the Serial Monitor. You will see prompts asking for various details needed to generate the certificate:

• Issue date and time of the certificate.
• Expiry duration of the certificate.
• Slots for storing the private key and certificate.
• Choice to generate a new key.

Step 7: Generate the Certificate

Respond to the prompts in the Serial Monitor. The program will generate a self-signed certificate based on your responses and display it along with its SHA1 fingerprint.

Troubleshooting

• If the Serial Monitor displays an error related to the ECC608 chip, ensure that the chip is correctly configured and locked.
• For any issues related to the Arduino IDE or board connections, consult the official Arduino forums or documentation.

Conclusion

You now have a self-signed certificate generated by the ECC608 chip. This certificate can be used for various cryptographic purposes, enhancing the security of your projects.