Raccoon is an open-source Bluetooth Low Energy Sniffer that consists of firmware for the Nordic nRF5x SoCs and a Python command line tool. It can follow connection request on all three advertisement channels by using three sniffer devices.

Raccoon was successfully tested on:

• Nordic nRF51 DK (PCA10028) with nRF51422
• Nordic nRF52 DK (PCA10040) with nRF52832
• Nordic nRF52840 DK (PCA10056) with nRF52840
• Nordic nRF52840 Dongle (PCA10059) with nRF52840
• Adafruit Bluefruit LE Friend with nRF51822
• Makerdiary nRF52840 MDK with nRF52840
• Makerdiary nRF52840 MDK USB Dongle with nRF52840
• Makerdiary Pitaya Go with nRF52840

The firmware requires the regular ARM-EABI-NONE toolchain. The Python command line tool was develop on Python 3 and requires the pySerial module It requires the nRF5 SDK. If not installed locally, the build system can automatically download it into the project folder.

With the dependencies in place, run make in the main project folder. Make will download the nRF5 SDK if needed.

Flashing depends on the used device.

Go to the correct folder:

• nRF51 DK: firmware/nrf/pca10028/armgcc
• nRF52 DK: firmware/nrf/pca10040/armgcc
• nRF52840 DK: firmware/nrf/pca10056/armgcc

Run make flash

The nRF52840 Dongle comes with a MBR and a Bootloader that supports firmware update via DFU mode. Here, we use the nRFConnect for Desktop tool:

• Download and install nRFConnect For Desktop
• Start nRF Connect and select Programmer
• Enter Bootloader mode by pressing RESET button - the red LED starts pulsing
• Select your device in the 'Select Device' pop-up in the upper left
• Add Hex file: firmware/nrf/pca10059/armgcc/_build/nrf52840_xxaa.hex
• Press 'Write'
• After successful write, the warning 'Nordic DFU Trigger Interface was not found' is shown. That's ok - Raccoon was flashed and is ready

There's no support to update via the BLE DFU. However, the LE Friend provides the regular SWD interface to upload the firmware with an JTAG/SWD programmer (e.g. a ST-Link or a SEGGER J-Link). Config files for OpenOCD are provided int the firmware/nrf/blefriend32 folder.

Drag-n-drop the hex file firmware/nrf/nrf52840_mdk/armgcc/_build/nrf52840_xxaa.hex to the disk drive named DAPLink of the board, and then Raccoon will be ready.

Follow the guide - Programming the nRF52840 MDK USB Dongle to flash the firmware firmware/nrf/nrf52840_mdk_usb_dongle/armgcc/_build/nrf52840_xxaa.hex.

Follow the guide - How to Program Pitaya Go to flash the firmware firmware/nrf/pitaya_go/armgcc/_build/nrf52840_xxaa.hex.

When running raccoon.py for the first time, it will create a template config file 'config.py' that lists all serial ports. Please edit config.py and uncomment the lines that refer to Raccoon sniffer device.

After configuration, start raccoon.py. It will list found devices and wait for a connection request. It will follow the first connection request. To follow only a specific device, you can set a BD_ADDR (MAC) filter with the --addr option.

During scanning, unique advertisements will be listed and a counter displays the total number of received devices. After connect, the number of Connection Events and the number of non-empty data packets are shown.

Example run:

$ pyclient/raccoon.py
[+] Config: output trace.pcap (pcap)
[-] Sniffer #0: port /dev/cu.usbmodem0006816168181, baud 1000000, rtscts 1, channel 37, version 9957-dirty
[+]  1. 00:1a:7d:da:71:01         ADV_IND  -46 dBm, Name: 'LE Counter', UUID16: FF10
[+]  2. 04:52:c7:f8:6e:57         ADV_IND  -97 dBm, UUID16: FEBE
[+]  3. 5e:5e:fe:16:21:19    ADV_SCAN_IND -102 dBm, UUID16: FE9F
[+]  4. 00:21:3c:ac:f7:38         ADV_IND  -56 dBm, UUID128: 200c9a66-0800-9e96-e211-818a400b0998
[+]  5. 1f:3a:8b:7a:e6:b8 ADV_NONCONN_IND  -97 dBm,
[+] CONNECTION 4a:dc:5a:84:78:fb -> 00:1a:7d:da:71:01 -- aa af9aaa9a, interval 30.00 ms, timeout_us 720.00 ms, latency 0
[+] TERMINATE, disconnect
[+] Restart sniffer on channel #37
[+]

Thanks for using raccoon

The current version allow to follow all Bluetooth 4.x connections. Optional supported features:

• LE Data Length Extension (DLE).
• Channel Selection Algorithm #2 (CSA #2) - only partially working yet

Encrypted connections are not supported yet. Sniffing encrypted connections requires the Long Term Key/Link Key to be present on the sniffer hardware.

For LE Legacy Connections, the link key can be retrieved using crackle if the pairing is observed.

To use Raccon with crackle, select packet format 'crackle' and then use crackle as descriped on the recorded .pcap trace: crackle -i trace.pcap -o decrypted.pcap

Logging connections with 2-MBit PHY or Coded PHY is not implemented yet.

The UART of the nRF5x devices only support a maximal baudrate of 1 mbps. This is not enough when the connection intervals are fully used. The new nRF52840 Dongle (PCA10059) supports the USD Device mode, which should be fast enough to even capture LE 2M PHY at max speed.