Is it possible to encrypt/decrypt buffer in RAM using Efuse block1/block2 keys?

[dmitryga]

Hi everybody!

I'm using secure boot + flash encryption with custom keys burned in Efuse block1 and block2. So these keys are known to me and I can encrypt some portion of data and send it to ESP in some way (TCP/IP for example). Can I decrypt this data like system APIs using keys in Efuse?

[WiFive]

No those keys are protected so you may as well just store another key in encrypted flash and use that.

[dmitryga]

But how spi_flash_write_encrypted can encrypt data with that keys? I don't want to read key bytes, I just want to ask CPU to encrypt/decrypt something instead of flash with these keys (like bootloader or other components do).

[ESP_igrr]

In case of encryption, ciphertext is passed straight to SPI controller, bypassing the CPU.