Latest status of Buttonless secure DFU in SDK 13.0

[sam wagner]

Hi,

I just got the email about SDK13.0 official release. The list of changes in this release include "Secure DFU improvements". What does it mean? Is Buttonless Secure DFU completely supported in this release?

Regards, Sam

[Hung Bui]

Hi Sam,

Compare to SDK v13 alpha, the buttonless example in the SDK v13 official doesn't change much.

• It is still in experimental mode

• Some issues on SDK v12 and 13 alpha were fixed such as the characteristic's write property missing, the bootloader_setting section missing were fixed.

• Now we use RAM retention register GPREGRET to set the flag to enter bootloader mode instead of writing to flash.

• Change the service's UUID to the Secure-DFU UUID

• Change from the DFU control point property from notification to indication

• Requires nRFutil v2.2.0

[sam wagner]

Hi Hung,

Thanks for the information. As far as I know, SDK12 does not support the sharing of BLE link encryption key between the bootloader and the firmware application.

Does SDK13 support a case where [1] Central and Device are bonded using BLE encryption (say JUST WORKS) and [2] Phone App triggers DFU by writing into the DFU endpoint, thereby making the Device switch to bootloader mode, [3] then the phone App transfers signed DFU image over the air to the device, and [4] the Device jumps to the new image after that?

We need to support the above scenario ASAP for our production code.

Regards, Sam