This configures ATECC608 secure chip from ESP32 and get a public key corresponding to slot 0 private key.
Prepare a host PC and automatically create and write a certificate with a Python script through serial communication.
Due to chip's secure function, once if it has configured, you can't change config contents.

Platformio with VS Code environment.
install "Espressif 32" platform definition on Platformio

Espressif ESP32-DevkitC
this project initializes both of I2C 0,1 port, and the device on I2C port 0 is absent.
pin assined as below:

  I2C 0 SDA GPIO_NUM_18
  I2C 0 SCL GPIO_NUM_19

  I2C 1 SDA GPIO_NUM_21
  I2C 1 SCL GPIO_NUM_22

Microchip ATECC608(on I2C port 1) (not supported TRUST&GO and TRUSTFLEX)

"git clone --recursive " on your target directory.
you need to change a serial port number which actually connected to ESP32 in platformio.ini.

First, on the host PC, run the python script in the scripts folder to prepare
the root certificate and signer certificate.
Then create a device certificate template (cert_chain.c) to allow one firmware to create individual device certificates for multiple devices.

On ESP32 side, add "cert_chain.c" above and execute "Upload" on platformio.
This completes a binary that can be used as a master.

When "deviceprovision.py" is executed on the host PC side, a series of operations
to extract the public key from the ESP32 side, sign it and write it back
will be executed.

For the second and subsequent ESP32s, simply copy the binary created above and
execute "deviceprovision.py" from the host PC again, and provisioning will proceed
automatically.

This software is released under the MIT License, see LICENSE.