DFU with password

[Jackxl]

Hi all. I have phone with nrf Tollbox and central device with DFU, SD130 2.0.0, SDK11. I would like flash application to central by OTA when I enter password in nrfToolbox. My central device doesn't have keyboard or display. Is it possible ? How ? I used DFU from this tutorial devzone.nordicsemi.com/.../ I have tried modify this DFU with passkey (static passkey), but with no result.

[Hung Bui]

Hi Jackxl,

Could you explain what you are able to do now ? Are you able to do DFU on your central ?

What exactly do you want to achieve ? You want to have bonding with the phone when doing DFU or you want to have a password required when anyone want to do DFU with your device ?

passkey bonding and password are not the same thing.

[Jackxl]

Hi Hung Bui. Yes, DFU works on my central and I want your second choice what you have mentioned: I want to have a password required when anyone want to do DFU with my device.I guess that separate dfu as in tutorial is peripheral, but application is central.

[Hung Bui]

I assume you are updating your central by switch it to peripheral mode and your phone as central to do DFU.

To add a password, you need to implement it on your own. Says the DFU target will reject DFU init packet if there is no "password" command is written on the DFU Control point characteristic. If you want to avoid attacker to sniff your connection and catch that fixed password, you can implement a scheme when the DFU target send to the DFU master a random number, and the DFU master have to encrypt it using the secret key (that hardcorded in the bootloader) and send the result back. The DFU target will check, if it match then it will allows the DFU process to be started.

Of course you would need to modify the DFU app on the phone. All the source code are available, so I don't think there would be any problem.

[Jackxl]

Fine. Where I can get source code of DFU app for phone ? Thx.

[Hung Bui]

Here you go: github.com/.../Android-DFU-Library