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Where to store software license key

Posted: Wed Mar 25, 2020 4:16 pm
by bonmotwang
Hello.

I am developing a product use ESP32 module.
The firmware image will be released / sold with a license key based on MAC address on each module.
My question is:
- Is it a good idea to use nvs_storage.c lib to save the key?
- Is it internal flash or SPI to the external. If it is external, it doesn't work for me because people can just copy the whole external flash.

Thanks

Re: Where to store software license key

Posted: Thu Mar 26, 2020 10:56 am
by ESP_Sprite
There is no internal flash, although you could perhaps use the eFuses for license purposes. If you do want to use the flash, I'd suggest you look into SecureBoot / flash encryption: that both makes it impossible to just copy the flash (as it's encrypted with a key that only the paired ESP32 knows) as well as read out the firmware and patch the licensing code.