Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

Elfving — Wed, 22 Jan 2025 14:41:10 GMT

[quote user="Elfving"]

Make sure that the BlueZ version supports LESC pairing. And you mentioned you're trying to do Just Works pairing with NoInputNoOutput, but if the sniffed packets indicate a numeric comparison failure it might be a mismatch in the pairing methods between the devices.

[/quote]

This gives the impression of both - ie. different approaches, hence the crash.

Regards,

Elfving

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

prashaanth — Wed, 22 Jan 2025 13:19:22 GMT

Atleast can you guide me like which approach is being taken here for the pairing process. Is it passkey mechanism or numeric comparison mechanism?

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

Elfving — Fri, 10 Jan 2025 12:47:59 GMT

[quote user="prashaanth"]How to enable the justworks pairing method?
[/quote]

I won't be able to help you regarding getting that working with BlueZ. Try stack overflow or BlueZ directly.

Regards,

Elfving

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

prashaanth — Thu, 09 Jan 2025 13:55:41 GMT

I could observe that when I do a default-agent on bluetoothctl

How to enable the justworks pairing method?

Then I try to pair the device I don't see the numeric comparison issue and it says Sent pairing DHKey check but later there are no logs regarding the security.

I am using the latest bluez which is 5.78. I am attaching the bt monitor logs for your reference. Attaching my sniffing logs once I made the default-agent to be on devzone.nordicsemi.com/.../without_5F00_numeric_5F00_key_5F00_issue.pcapng devzone.nordicsemi.com/.../btmon_5F00_logs.txt

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

Elfving — Wed, 08 Jan 2025 12:00:20 GMT

Are there any error logs with info on any of the devices?

Regards,

Elfving

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

prashaanth — Tue, 07 Jan 2025 11:40:21 GMT

It is not a nrf I am filtering out for my device mac address in wireshark logs so if you see the slave is my device (which is having bluetooth 4 with bluez 5.55 version) mac address and master is the app so I am trying to sniff the bluetooth layer. When I sniff I see the packets says numeric comparison failure. There is the key exchange happenign but it fails in the numeric comparison of the keys.

What could be the possibility here?

RE: Getting rcvd Pairing Failed:Numeric Comparison Failed during pairing process

Elfving — Tue, 07 Jan 2025 10:29:22 GMT

Hi,

What is running on the embedded device? Have you checked that you can get a working connection with other SW running on it, or with a different app? Is it an nRF?

Regards,

Elfving