Error: -- Reserved -- when installing wireless stack after installing auth key

[HRadt.1]

Baseline:

I can install FUS and Wireless Stack binaries via SWD just fine. I can re-install the wireless stack without a problem when no auth key is programmed.

My problem:

As soon as I install an auth key, installing/updating the wireless stack results in an

Error: -- Reserved --

I recon this is because the FUS now also checks wireless stack binaries against the user auth key. In this situation I would expect the error to be: FUS_STATE_IMG_NOT_AUTHENTIC

I tried signing the wireless stack binary with my auth key (using the prepareimage tool). But I'm quite sure I did something wrong, because when I install that signed binary I actually receive the FUS_STATE_IMG_NOT_AUTHENTIC error.

So the second question is:

How to sign an STM binary with a user auth key?

AN5185 states in Chapter 4: "The instruction to sign a binary with user authentication key are provided in STM32CubeProgrammer user manual." But I only see the commands to write they key via the bootloader.

[Remi QUINTIN]

There are 2 potential error causes

• Pleased check the way the key was used (MSB/LSB, Little/Big Endian)
• You added a new layer of signature, but did you add the additional footer at the end of the image to ensure a correct format?

If you agree, you could send us your key and the signed image so that we could check .