How to get STM32H secure firmware to work with external crypto chip

[DanW]

Need help on the secure programming support for STM32H753V MCU, OTA using hardware secure chip ATECC608A. Any example code or procedure would be a great help. Thank you.

[Pavel A.]

Can you be a bit more specific? OTA means over the air. STM32H753 is not wireless - no bluetooth or wi-fi.

But STM32H753 has its own crypto accelerators.

-- pa

[DanW]

Thanks for the reply Pavel,
Maheshwar, could you advise Pavel on the below?
Can you be a bit more specific? OTA means over the air. STM32H753 is not wireless - no bluetooth or wi-fi.
But STM32H753 has its own crypto accelerators.
Cheers!
Danny

[Tesla DeLorean]

Pretty sure it doesn't have Elliptic Curve signing methods in the H7 HW

I'd lean toward doing SECP192R1 internally via SW

Stage the crypted firmware image in an unused area of internal flash during OTA download.

[DanW]

Thank you for the reply . Actually we are using the wifi to update the firmware for this we have a wifi device connected to the microcontroller(UART interface ) . What we want to know is how to interface the external secure chip ATECC608A device . For ATECC608A device we have I2C interface and how to link with secure boot process to this device . Please let us know procedure and appreciate if there is any reference source for that.

Cheers!

[Tesla DeLorean]

As it's an ATMEL/MICROCHIP thing there's probably not going to be "reference source" for such from ST, you likely need to port examples and merge into your current implementation. Check related ATMEL and ST application notes. Perhaps discuss with an ST FAE or domain expert, or with your contractor.

Skimming the docs, the biggest advantage of the ATECC608A is that you can secure/hide your keys inside it.

https://github.com/RiddleAndCode/ECLet_STM32