rfcat-py3 2.1.4

the swiss army knife of subGHz

Welcome to the rfcat project

Table of Contents

• Goals
• Requirements
  • Other requirements
  • Build requirements
• Development
  • "Gotchas"
• Installing on hardware
  • Allowing non-root dongle access
  • Supported dongles
  • Your build environment
• Installing with bootloader
  • To install
• Installing client
• Using RfCat
• Cool Projects Using RfCat
• Epilogue

GOALS

The goals of the project are to reduce the time for security researchers to create needed tools for analyzing unknown targets, to aid in reverse-engineering of hardware, and to satiate my rf lust.

REQUIREMENTS

RfCat requires Python 3.8 or newer. Python 2 support has been removed.

Other requirements

• python usb
• libusb - should be able to work with either 1.x or 0.1 versions. please let us know if you run into issues.
• pyreadline (especially for Windows)
• PySide6 (for Spectrum Analyzer GUI). Not installed automatically; install with the specan extra: $ pip install 'rfcat[specan]'
  or directly: $ pip install 'PySide6>=6.4'

Build requirements

• Make
• SDCC

DEVELOPMENT

New development efforts should copy the "application.c" file to "appWhateverMyToolIs.c" and attempt to avoid making changes to other files in the repo if at all possible. that is only a recommendation, because future bug-fixes in other libraries/headers will go much more smoothely for you.

Gotchas

A couple gotchas to keep in mind while developing for the cc1111

• The memory model includes both "RAM" and "XDATA" concepts, and standard RAM variables and XDATA variables have different assembly instructions that are used to access them. this means that you may find oddities when using a function written for XDATA on a standard RAM variable, and vice-versa.
• Variables should be defined in a single .c file, and then "externs" declared in a .h file that can be included in other modules. this is pretty standard for c programs, but both this and the previous point caused me difficulties at some points, and i found myself unsure what was causing my troubles.
• RAM memory is not cheap. use it sparingly.
• You need to set the radio into IDLE mode before reconfiguring it
• You need to set the radio into TX mode before writing to the RFD register (firmware) as it is a 1-byte FIFO.

INSTALLING ON HARDWARE

Installing and getting up to speed with rfcat...

First things first. Using rfcat requires that you either use the python client in root mode (sudo works well), or configure udev to allow non-root users full access to the dongle. you must also have one of the supported dongles flashed with the necessary application firmware.

allowing non-root dongle access

sudo cp etc/udev/rules.d/20-rfcat.rules /etc/udev/rules.d
sudo udevadm control --reload-rules

Please make sure any user accounts you want to allow access to the RfCat dongle are members of the dialout group.

This tool is created, maintained, and used primarily on linux. make and sdcc must be installed for creating new firmware and some of the helper functions we provide through make.

supported dongles

• YARDStick One
• cc1111emk (aka DONSDONGLES)
• chronos watch dongle (aka CHRONOSDONGLE)
• imme (limited support for both IMME and IMMEDONGLE)
  • imme dongle is not really usable as of 1/31/2012

GoodFET

            --------------------------------
            |                         1  2 |
            |                         3  4 |
       ------                         5  6 |  
       | USB                          7  8 |
       ------                         9 10 |
            |                        11 12 |
            | GoodFET                13 14 |
            --------------------------------

Chronos Dongle

            --------------------------------
            |                              |
            |             RST 1  2 TP      ------
            |             GND 3  4 VCC      USB |
            |         DC/P2_2 5  6 DD/P2_1 ------
            | Chronos                      |
            --------------------------------

               GoodFET            Chronos           GreatFET            Chronos
                 PIN                PIN              PIN                  PIN

                  1 <----- DD -----> 6              J1.37 <----- DD -----> 6
                  2 <----- VCC ----> 4               J1.2 <----- VCC ----> 4
                  5 <----- RST ----> 1              J1.40 <----- RST ----> 1
                  7 <----- DC -----> 5              J1.39 <----- DC -----> 5
                  9 <----- GND ----> 3               J1.1 <----- GND ----> 3

EMK Dongle

            --------------------------------
            | 2 4 6 8 10   2 4 6 8 10      |
            | 1 3 5 7 9    1 3 5 7 9       |
            |-TEST-PINS----DEBUG-PINS------|
            |                              |
       ------                              |
       | USB                               |
       ------                              |
            | Don's Dongle (EMK)           |
            --------------------------------

               GoodFET              EMK               GreatFET             EMK  
                 PIN             DEBUG PIN              PIN            DEBUG PIN

                  1 <----- DD -----> 4              J1.37 <----- DD -----> 4
                  2 <----- VCC ----> 2               J1.2 <----- VCC ----> 2
                  5 <----- RST ----> 7              J1.40 <----- RST ----> 7
                  7 <----- DC -----> 3              J1.39 <----- DC -----> 3
                  9 <----- GND ----> 1               J1.1 <----- GND ----> 1

YARD Stick One

Pogo pads on the back are clearly marked, but if you want to use the header...

            -----------------------------------------
            | YARD Stick One      2 4 6 8 10 12 14  |
            |                     1 3 5 7 9  11 13  ------
            |                                        USB |
            |                                       ------
            |                                       |
            -----------------------------------------

    
               GoodFET           YARD Stick One       GreatFET           YARD Stick One
                 PIN                 PIN               PIN                 PIN

                  1 <----- DD -----> 1               J1.37 <----- DD -----> 1
                  2 <----- VCC ----> 2                J1.2 <----- VCC ----> 2
                  5 <----- RST ----> 5               J1.40 <----- RST ----> 5
                  7 <----- DC -----> 7               J1.39 <----- DC -----> 7
                  9 <----- GND ----> 9                J1.1 <----- GND ----> 9

INSTALLING WITH BOOTLOADER

Steps required for all firmware installs and updates

You will also need to install the build requirements of python-usb, libusb-1.0.0, make, and sdcc.

• python-usb
• libusb-1.0.0
• make
• sdcc

sudo apt install python-usb libusb-1.0.0 make sdcc

For sdcc and its dependency, sdcc-libraries, you may need to download it from a earlier release's repository if you are on a newer version of Debian or Ubuntu such as:

• https://packages.debian.org/stretch/sdcc

Next, your user must have read/write access to the dongle when it shows up to the operating system.
For most Linux distros, this means you have to be a member of the "dialout" group.

usermod -a -G sudo $USER
su - $USER

You will also need permanent symlinks to the USB serial devices that will communicate with the CHRONOS, DONSDONGLE or YARDSTICKONE bootloader when required. If you haven't done this step already (see above), then run:

sudo cp etc/udev/rules.d/20-rfcat.rules /etc/udev/rules.d
sudo udevadm control --reload-rules

Steps for bootloader + firmware installs via hardware debugger

To prepare your dongle for the first time, you'll need to hook up your debugger as described above

Intended development model is using a GoodFET although one of our developers uses the chipcon debugger from Texas Instruments.

cd rfcat/firmware/
make testgoodfet

This will read info from your dongle using the GoodFET. you should see something like:

SmartRF not found for this chip.
Ident   CC1111/r1103/ps0x0400
Freq         0.000 MHz
RSSI    00

• make backupdongle will read the current firmware from your dongle to the file .../bins/original-dongle-hex.backup. (make restoredongle) to revert to the original firmware.
• make clean installRfCatChronosDongle will clean, build, and install the RfCat (appFHSSNIC.c) firmware for a Chronos dongle.
• make clean installRfCatDonsDongle will clean, build, and install the RfCat (appFHSSNIC.c) firmware for a cc1111emk.
• make clean installimmesnifffw will clean, build, and install the RfSniff firmware for the IMME girls toy from girltech

Dependencies: Fergus Noble's CC-Bootloader (slightly modified). For your convenience, hex files are provided in the CCBootloader sub-directory in firmware.

Source can be found here

• https://github.com/AdamLaurie/CC-Bootloader

Which is branched from here

• https://github.com/fnoble/CC-Bootloader

and do:

(install rfcat_bootloader from the CC-Bootloader subdirectory to somewhere on your execution path)

cd firmware

for EMK/DONSDONGLE: make installdonsbootloader

for CHRONOS: make installchronosbootloader

for YARDSTICKONE: make installys1bootloader

now unplug the debugger and plug in your USB dongle.

If you have just installed the bootloader, the dongle should be in bootloader mode, indicated by a solid LED.

Steps for firmware updates via USB port

If you are re-flashing a dongle that is already running rfcat firmware, such as a YarstickOne, the Makefile targets will force it into bootloader mode for you, but you can manually put it into bootloader mode either by holding down the EMK/DONS button as you plug it into USB (on the CHRONOS or YARDSTICKONE jumper P2_2/DC to GROUND), or by issuing the command d.bootloader() to rfcat in interactive mode (rfcat -r), or by issuing the command rfcat --bootloader --force from the command line.

Once you have a solid LED, or if you're running an rfcat dongle, you can do the following:

cd firmware

for EMK/DONSDONGLE:

• make installRfCatDonsDongleCCBootloader

for CHRONOS:

• make installRfCatChronosDongleCCBootloader

for YARDSTICKONE:

• make installRfCatYS1CCBootloader

The new version will be installed, and bootloader exited.

Installing client

Dependencies

• python-usb
• libusb

Install rfcat onto your system. on most linux systems, this will place rfcat and rfcat_server in /usr/local/bin/ and rflib into /usr/*/lib/python3/dist-packages

Installation

# standard install
pip install .

# editable/development install (runs from the checked-out directory)
pip install -e .

I highly recommend installing ipython:

• For deb/ubuntu folk: apt-get install ipython3

Using rfcat

If you have configured your system to allow non-root use:

• type "rfcat -r" (if your system is not configured to allow non-root use, prepend "sudo" or you must run as root) you should have now entered an interactive python shell, where tab-completion and other aids should make a very powerful experience i love the raw-byte handling and introspection of it all.

• try things like:

  • d.ping()
  • d.discover()
  • d.debug()
  • d.RFxmit('blahblahblah')
  • d.RFrecv()
  • print(d.reprRadioConfig())
  • d.setMdmDRate(19200) # this sets the modem baud rate (or DataRate)
  • d.setPktPQT(0) # this sets the preamble quality threshold to 0
  • d.setEnableMdmFEC(True) # enables the convolutional Forward Error Correction built into the radio

while the toolset was created to make communicating with <ghz much easier, you will find the cc1111 manual from ti a great value. the better you understand the radio, the better your experience will be. play with the radio settings, but i recommend playing in small amounts and watch for the effects. several things in the radio configuration settings are mandatory to get right in order to receive or transmit anything (one of those odd requirements is the TEST2/1/0 registers!)

If you watched any of my talks on rfcat, you will likely remember that you need to put the radio in IDLE state before configuring. (I said it three times, in a row, in different inflections).

However, you will find that I've done that for you in the client for most things. The only time you need to do this yourself are: * If you are doing the changes in firmware * If you are using the "d.poke()" functionality * if you use "d.setRFRegister()", this is handled for you * use d.setRFRegister()

IMMESniffer key bindings

When running with an IMME device, the sniffer UI accepts these key bindings:

Key	Action
q / a	Inc / dec highest sync word nibble
w / s	Inc / dec high-middle sync word nibble
e / d	Inc / dec low-middle sync word nibble
r / f	Inc / dec lowest sync word nibble
z	No sync word matching
menu / bye!	Inc / dec modulation type
up / down	Inc / dec receive bandwidth
right / left	Inc / dec baudrate
p / Enter	Inc / dec frequency
o / ,	Faster inc / dec frequency
i / m	Even faster inc / dec frequency
l / k / j / h	Set freq to 915 / 868 / 433 / 315 MHz
t / v	Inc / dec channels
g	Set channel to 0
SPACE	Switch screens
SPKR	Toggle carrier TX mode

MSF Relay

rfcat_msfrelay is a lightweight web server that exposes rfcat as a Metasploit Hardware Bridge, enabling use of the rftransceiver Metasploit extension with any rfcat-compatible dongle.

# start the relay (default: localhost, user msf_relay, pass rfcat_relaypass)
rfcat_msfrelay

Then from Metasploit:

use auxiliary/client/hwbridge/connect
set httpusername msf_relay
set httppassword rfcat_relaypass
run

Once the hardware bridge session is open, run post/hardware/rftransceiver/... modules are available. The relay supports freq, modulation, baudrate, channel, sync word, TX, RX, and related parameters. Not all rfcat methods have Metasploit equivalents - use rfcat directly for research and Metasploit for exploit delivery.

rfox

rfox is a companion CLI built on top of rflib that wraps the most common day-to-day RF workflows - capture, replay, decode, sweep, jam, brute-force, and more - behind a single consistent interface and a shared pcap capture format. Install it separately if you want a higher-level tool on top of rfcat.

External Projects

ZWave Attack: https://github.com/initbrain/Z-Attack

Epilogue

Other than that, hack fun, and feel free to share any details you can about successes and questions about failures you are able!

@ and the rest of the development team.