Issues with Zephyr Peripheral NFC Pairing Example

RE: Issues with Zephyr Peripheral NFC Pairing Example

Simonr — Tue, 02 May 2023 09:50:43 GMT

Sorry about the late reply. I've been out of office travelling for the last week.

I think the reason you're not seeing this data on Wireshark is because the OOB pairing share encryption keys/authentication data over the "alternative" communication channel, in this case being NFC.

Wireshark won't be able to sniff any data transferred over NFC as it's a completely different protocol and frequency than BLE.

Best regards,

Simon

RE: Issues with Zephyr Peripheral NFC Pairing Example

andreribeiro423 — Wed, 26 Apr 2023 10:27:32 GMT

I checked out the Sniffing the pairing procedure of a connection in the nRF Sniffer user guide. Since I am using LE Secure Connections I had to enable Secure Connections Debug Mode on the device. So, for that I added the CONFIG_BT_USE_DEBUG_KEYS=y on the prj.conf. However, after this I continued not to see any Security Manager Protocol (SMP) packet exchanged in Wireshark during the pairing procedure. I also checked out the menuconfig for exploring the available Kconfig options and ensure that the Secure Connections Debug Mode option is enabled.
Thank you for your help!

RE: Issues with Zephyr Peripheral NFC Pairing Example

Simonr — Tue, 04 Apr 2023 08:56:46 GMT

[quote user=""]I cannot see any Security Manager Protocol (SMP) packet exchanged in Wireshark[/quote]

This is the intended behavior, as a sniffer shouldn't be able to join in on the OOB pairing without having any of the OOB data on the sniffer side as well. You can check out the Sniffing the pairing procedure of a connection in the nRF Sniffer user guide.

[quote user=""](even when cleaning the bonds of the nRF52-DK board)[/quote]

Do you erase the bond on both ends here though? When the devices have paired (and then bonded) once, they won't have to pair again on subsequent connections as they have already found a LTK (long term key) to start encrypted communication upon connection. If you erase bonding info on both devices, you should be able to see the same pairing info as you did initially.

Best regards,

Simon