Central can't properly encrypt to mode 1 lvl 3, pairing not supported

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Tien Tran — Wed, 28 Jun 2017 17:38:34 GMT

Hung Bui,

I haven't used the sniffer before, but I got it working and it helped me debug the problem. Looks like the issue was with the Qardio Arm itself, not wanting to pair with anything besides my phone. After a factory reset I got past the sd_ble_gap_authenticate(). Thanks!

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Tien Tran — Wed, 28 Jun 2017 17:14:35 GMT

Turns out my problem was with the BP monitor itself. For some reason it refused pairing with any other device except my phone. I tested using multiple other phones and even with a linux system. To solve my problem I simply figured out how to factory reset the BP monitor, and then I was able to pair/bond with other devices.

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Hung Bui — Mon, 26 Jun 2017 11:07:48 GMT

No, I don't think you need to do anything else. If you can provide a sniffer trace, it would be very useful.

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Tien Tran — Fri, 23 Jun 2017 15:24:41 GMT

Hung Bui, I just tried that and unfortunately, same auth status (0x85). Is there something I need to do prior to sd_ble_gap_authenticate()? The first thing ever I do, besides initializing, is running sd_ble_gap_connect(). I already know the device Addr so I don't do any scanning for advertisements. Once im connected, I store the connection handle, and use it immediately in sd_ble_gap_authenticate(). Do you think I have to do any kind of scanning before I can authenticate? (advertisements/services/characteristics, etc)

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Hung Bui — Fri, 23 Jun 2017 07:37:30 GMT

I assume that the blood pressure device require lv3 bonding, meaning you need MITM.

Could you try MITM =1 and keyboard and display enabled ?

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Tien Tran — Thu, 22 Jun 2017 15:10:08 GMT

Hung Bui, I've been messing around with the parameters mainly because I've been desperate... haha but I have tried it also with oob = 0, no IO cap, and MITM set to 0. Still the exact same error unfortunately.

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Hung Bui — Thu, 22 Jun 2017 08:53:56 GMT

Why do you set MITM to 1 and then no IO capability and no OOB, how would you plan to do MITM bonding ? I assume that why the peripheral rejected pairing .

register_param.sec_param.mitm         = SEC_PARAM_MITM;            // mitm    = 1
register_param.sec_param.io_caps      = SEC_PARAM_IO_CAPABILITIES; // io cap  = 3  (none)
register_param.sec_param.oob          = SEC_PARAM_OOB;             // oob     = 0

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Tien Tran — Wed, 21 Jun 2017 15:34:17 GMT

Here's what I did exactly on the nRF Connect android app. Just copying the log:

Connected to 5C:D6:1F:20:0B:A5 
Services discovered        //After this line, I wrote to characteristic
Deviced bonded
Data written to **characteristic uuid**, value: (0x) F1-01  //start command
"(0x) F1-01" sent
Data written to **characteristic uuid**, value: (0x) F1-02  //stop command
"(0x) F1-02" sent

So it looks like right after I "wrote" to the characteristic, my phone automatically bonded with the bp monitor. If it can bond, this means it should be able to pair correct?

I will keep messing around with the parameters, and thank you also for the information about gap_encrypt()

RE: Central can't properly encrypt to mode 1 lvl 3, pairing not supported

Petter Myhre — Wed, 21 Jun 2017 09:06:21 GMT

When you are using nRF Connect on Android, are you pairing? If not, it is a bit strange that you are able to write. Are you sure you are writing to the same characteristic value in both cases? It is a bit difficult to say why the peripheral returns pairing not supported, but it could be that it doesn't like the security parameters you are trying to pair with. If you are pairing with the nRF connect, and you have access to a sniffer (for example nRF Sniffer) I would do a sniffer trace of both connections and see if there are any differences in regards to the pairing process.

PS. You should use sd_ble_gap_authenticate() when you want to pair/bond. If you bond you will share encryption keys that can be used in a later connecting, and then you will use sd_ble_gap_encrypt().