sniffing a laser tape

[erltot]

First time using the sniffer.

I want to sniff out the communication for a laser tape measuring device (Boosch GLM 50C)

I noticed that I am unable to sniff out anything when using with an android phone (is it because of a pairing operation?) I did get some information in packets when using an iphone, but after the initial connection, I can only see the advertisement packets (when not connected)..

Can't it be done?

Wireshark log bosch.pcapng

CONNECT_REQ recieved bosch_2_.pcapng

[endnode]

That's hard to say based on your information. If you are sure that this device is using BLE protocol not classic BR/EDR and that you see the advertisement then it should be done. In the worst case you won't be able to decode PDU payload if you don't catch initial pairing&bonding procedure but if you have the chance then simply unbond the device in the phone and sniff that connection as well. If you don't see CONNECT_REQ and subsequent connection link packets then most probably sniffer missed that and you should repeat the test or place sniffer differently to limit packet loss.

[Roger Clark]

An easier option is probably to reverse engineer the app

[erltot]

@endnode Updated the question with a wireshark log, i can't see any connect req but i'll try some more. It is BLE protocol - I can connect with the nRF Connect (ios) app and read services and characteristics (unknown + device information)

@Roger Clark I'm not familiar with app programming at all, I know android has some bluetooth logging functionality avaiable in debug mode - is this what you were thinking about?

[endnode]

I guess Roger meant to disassemble Android app which is JAVA so it's fairly possible, there are well known techniques and even they use obfuscation it's usually possible to get through it - for decent hacker;)

[endnode]

From your sniffer log it's obvious that it missed the connection (assuming there was some, gap in timing after packet #46 suggests that). What nRF51 board are you using? Do you have all phone, sniffer and Bosh thing close together during experiments? Note that Nordic sniffer has some limitations in sensitivity and that people who do such tasks for living are using specialized and much more expensive tools like Frontline or Ellysis analyzers (1-20k USD).