Back in September the GNU Radio 2016 (GRCon16) conference was held. GRCon16 is an annual conference centered around the GNU Radio Project and community, and is one of the premier software defined radio industry events. GNU Radio is an open source digital signals processing (DSP) tool which is often used with SDR radios.
One of our favorite talks from the conference is Micheal Ossmanns talk on his idea to create a low cost $150 RX/TX radio. Micheal Ossmann is the creator of the HackRF which is a $299 USD RX/TX capable SDR. It was one of the first affordable general purpose wide frequency TX capable SDRs. Micheal also mentions his other projects including Neapolitan which will be an add on for the HackRF which will enable full-duplex communications and Marizpan which will essentially be a single board Linux SDR using the HackRF circuit.
GRCon16 - Low-Cost SDR Hardware, Mike Ossmann
Another is Balints talk on “Hacking the Wireless World” where he does an overview of various signals that can be received and analyzed or decoded with an SDR. Some applications he discusses include Aviation, RDS Traffic Management Channel, Radio Direction Finding, OP25, IoT, SATCOM and his work on rebooting the ISEE-3 space probe.
GRCon16 - Hacking the Wireless World, Balint Seeber
Earlier this week wired.com released a story indicating that researchers from the University of Birmingham have discovered two vulnerabilities that can be used to unlock almost any car. The first vulnerability concerns Volkswagen Group vehicles (VW, Audi, SEAT, Skoda) sold since 1995. Essentially their research found that the keyless entry systems of VW Group vehicles relies only on a few global master keys which they have been able to recover through reverse engineering of an undisclosed component used in a VW car. Then by sniffing the wireless key’s signal with an RF module or SDR like the RTL-SDR or HackRF they are able to recover the cryptographic algorithms used and then using the global key clone the wireless key signal, which can then be re-transmitted with a simple Arduino.
In their second research findings, the researcher’s write how they have been able to crack the Hitag2 rolling code system which is used in many vehicles such as Alfa Romeo, Chevrolet, Citroen, Dacia, Fiat, Ford, Lancia, Mitsubishi, Nissan, Opel, Peugot and Renault. Again, the hack works by sniffing a few wireless keyfob rolling code signals with an SDR or other device. Once the signals have been sniffed a simple laptop computer can reportedly break the encryption within one minute.
Here are some interesting excerpts from the conclusions of the paper:
The results of this paper show that major manufacturers have used insecure schemes over more than 20 years. Due to the widespread use of the analyzed systems, our findings have worldwide impact. Owners of affected vehicles should be aware that unlocking the doors of their car is much simpler than commonly assumed today. Both for the VW Group and the Hitag2 rolling code schemes, it is possible to clone the original remote control and gain unauthorized access to the vehicle after eavesdropping one or a few rolling codes, respectively. The necessary equipment to receive and send rolling codes, for example SDRs like the USRP or HackRF and off-the-shelf RF modules like the TI Chronos smart watch, are widely available at low cost.
A successful attack on the RKE and anti-theft system would also enable or facilitate other crimes:
– theft of the vehicle itself by circumventing the immobilizer system or by programming a new key into the car via the OBD port with a suitable tool
– compromising the board computer of a modern vehicle, which may even affect personal safety, e.g., by deactivating the brakes while switching on the wiping system in a bend
– inconspicuously placing an object or a person inside the car. The car could be locked again after the act
– on-the-road robbery, affecting the personal safety of the driver or passengers if they (incorrectly) assume that the vehicle is securely locked
Note that due to the long range of RKE systems it is technically feasible to eavesdrop the signals of all cars on a parking lot or at a car dealer by placing an eavesdropping device there overnight. Afterwards, all vulnerable cars could be opened by the adversary. Practical experiments suggest that the receiving ranges can be substantially increased: The authors of [18] report eavesdropping of a 433 MHz RFID system, with technology comparable to RKE, from up to 1 km using low-cost equipment.
The findings were presented at the Usenix Advanced Computing Systems Association conference during August 10-12, 2016 in Austin, TX. The white paper is titled “Lock It and Still Lose It—On the (In)Security of Automotive Remote Keyless Entry Systems” and can be downloaded here. Of course they did not publish the actual VW master keys in their paper and they have notified VW and NXP who make the Hitag2 chips in advance, noting that Hitag2 had actually been broken for several years prior.
Back in February we showed how Smay Kamkar was able to bypass rolling codes with his RollJam device, however the findings by these researcher’s is different in that they are actually able to generate new rolling codes, such that a simple Arduino with transmitter can act as a second wireless remote.
A $40 Arduino which can be used to record wireless rolling codes, then transmit new ones once the encryption has been broken.
Over on his YouTube channel user Gareth has uploaded a video that shows a full tutorial on quickly decoding an On Off Keyed (OOK) signal with a HackRF (or RTL-SDR) and the Inspectrum software. Once decoded he then shows how to use a Yardstick One to duplicate the signal.
Inspectrum is a Linux based program that allows you to easily determine various parameters of a digital modulated signal by positioning an overlay over the waveform of a signal recorded with an SDR. Basically Gareth’s process is to first extract signal level values using Inspectrum, then secondly use a simple Python program to turn these values into binary bits, which gives him the data packet. He is then finally able to write another quick Python program to interface with the Yardstick One and retransmit the string.
The Yardstick One is a multipurpose radio (not a SDR) for transmitting modulated signals like OOK.
My quickest and easiest method for OOK signal decoding & replication in 2016
Mario Filippi, a regular contributor to our blog and to the SDR community recently wrote in with an article showing how he built an S-Band (2 – 4 GHz) antenna for use with the HackRF. Of course the antenna can be used with any other SDR that can receive in this range, or with an RTL-SDR and downconverter. We post his article below.
S -Band Antenna for use with the HackRF One Author: Mario Filippi, N2HUN
Ever since purchasing a HackRF One, which receives from 1 MHz – 6.0 GHz I’ve always wanted to explore the world above 1 Gig, specifically the 2.0 – 2.7 GHz portion of the S-band. This portion of the band is populated with satellite communications, ISM, amateur radio, and wireless networks. A good, homebrew antenna for S-band was needed, so with parts mostly from the junk box, a 2250 MHz S-band right hand circularly polarized omni-directional antenna was built. Below is a step by step tutorial on building this antenna. Plans were from UHF-Satcom’s site.
rtl_fm / rx_fm: Allows you to decode and listen to FM/AM/SSB radio. rtl_sdr / rx_sdr: Allows you to record raw samples for future processing. rtl_power / rx_power: Allows you to do wideband scans over arbitrarily wide swaths of bandwidth by hopping over and recording signal power levels over multiple chunks of spectrum.
rx_tools is based on SoapySDR which is an SDR abstraction layer. If software is developed with SoapySDR, then the software can be more easily used with any SDR, assuming a Soapy plugin for that particular SDR is written. This stops the need for software to be re-written many times for different SDR’s as instead the plugin only needs to be written once.
rx_power scan with the HackRF at 5 GHz over 9 hours.
"Pokémon Go" is the latest in smartphone augmented reality gaming crazes. You may have already heard about the game on the news, or seen kids playing it in your neighborhood. To play, players must walk around in the real world with their GPS enabled smartphone, collecting different virtual Pokémon which appear at random spots in the real world, replenishing the virtual items need to collect Pokemon at "Pokéstops" and putting Pokémon to battle at "Gyms". Pokéstops and gyms are often city landmarks such as popular shops, fountains, statues, signs etc. For those who have no idea what "Pokémon" are: Pokémon are fictional animals from a popular children's cartoon and comic.
Since the game is GPS based, Stefan Kiese decided to see if he could cheat at the game by spoofing his GPS location using a HackRF software defined radio. The HackRF is a relatively low cost multipurpose TX and RX capable software defined radio. When playing the game, players often walk from Pokéstop to Pokéstop, collecting Pokémon along the way, and replenishing their items. By spoofing the GPS signal he is able to simulate walking around in the physical world, potentially automating the collection of Pokémon and replenishment of items at Pokéstops.
To do this he used the off the shelf "GPS-SDR-Sim" software by Takuji Ebinuma which is a GPS Spoofing tool for transmit capable SDR's like the HackRF, bladeRF and USRP radios. At first, when using the software Stefan noticed that the HackRF was simply jamming his GPS signals, and not simulating the satellites. He discovered the problem was with the HackRF's clock not being accurate enough. To solve this he used a function generator to input a stable 10 MHz square wave into the HackRF's clock input port. He also found that he needed to disable "Assisted GPS (a-gps)" on his phone which uses local cell phone towers to help improve GPS location tracking.
Next he was able to use the GPS-SDR-Sim tools to plot a simulated walking route and see his virtual character walking around on the real world map. A warning if you intend on doing this: Remember that 1) spoofing or jamming GPS is highly illegal in most countries outside of a shielded test lab setting, so you must ensure that your spoofed GPS signal does not interfere with anything, and 2) the game likely has cheating detection and will probably ban you if you don't simulate a regular walking speed.
Over on his ‘SDR4Everyone’ blog author Akos has recently uploaded a new post that reviews the HackRF One, and also compares it against the SDRplay RSP and RTL-SDR. In his review he discusses his first impressions of the HackRF, his concerns about it being labelled as a transceiver, and some of its various features. He also does a screenshot comparison of the HackRF, RSP and RTL-SDR on shortwave reception and image rejection performance. Akos also notes that there are not many applications in the high gigahertz range that cannot be done with cheaper or more specialized equipment. Finally he concludes that the HackRF is not very sensitive or good at RX in general, but still has enough features to make it a worthwhile purchase for some people.
To reverse engineer the drones wireless communications system the teams used software defined radios like the HackRF and BladeRF, and also an alternative method involving just using an Arduino and nRF24L01+ receiver chip. Once the signal was received, they used GNU Radio to decode the signal into packets of data. After analyzing the data they found that the data bytes were easily reverse engineered and then were able to transmit their own data packets to control the drone. The post goes into further detail on the specifics of the reverse engineering.
The Syma X8C drone to be stolen in the competition.
