nRF5340 : How to update encrypted net core app update bin to network core

[Siddharth Kachhia]

`Hi There,

For nRF5340 board, If I want to update encrypted net core bin file using FOTA, then what are the options to achieve it.

I have created encrypted image manually by applying --encrypt option with imgtool python script. I have used net_core_app_to_sign.bin and encrypted it with imgtool manually.

Questions:

1) Can I update net core of nRF5340 with encryption ?

2) Do netboot of nRF5340 provides support of encrypt/decrypt option ?

3) I have tried to update encrypted net core image similar way as app core but did not succeed.

4) Can I use MCUBOOT's -  "CONFIG_BOOT_ENCRYPT_EC256" kconfig option to netboot of nRF5340 ?

[Sigurd Hellesvik]

Hi Siddharth,

For encrypted images on both cores, we can talk about it in 287470.

4) Can I use MCUBOOT's -  "CONFIG_BOOT_ENCRYPT_EC256" kconfig option to netboot of nRF5340 ?

No, this option is not available for netboot.
The netboot bootloader does not have support for encryption.

Regards,
Sigurd Hellesvik

[Siddharth Kachhia]

Hi Sigurd,

Sure. Thanks

[Siddharth Kachhia]

I have found one issue with encrypted app_update.bin is the after reboot due to encrypted image, it goes performing net core update instead of app core. Have you found this type of issue with encrypted app core image ?

I have encrypt app_to_sign.bin with imgtool command and used it in FOTA. After flashing and rebooting, it goes to update net core but not app core. Any idea for this behavior ?

[Sigurd Hellesvik]

Hi

Since we do not support encrypted images for MCUBoot yet, I am not able to help you with this issue now.

I am not able to say anything about when we will support this. If you have questions about our timeline, please contact your regional sales manager.

Regards,
Sigurd Hellesvik