It doesn’t matter how many bits your password has, how proven your encryption is, or how many TrueCrypt volumes are on your computer. If someone wants data off your device, they can get it if they have physical access to your device. This is the ‘evil maid’ security scenario, named after hotel maids on the payroll of a three-letter agency. If someone has physical access to a laptop – even for an hour or two – the data on that laptop can be considered compromised. Until now, there has been no counter to this Evil Maid scenario, and for good reason. Preventing access to data even when it is in the possession of an Evil Maid is a very, very hard problem.
When I start up a new project, one that’s going to be worth writing up later on, I find it’s useful to get myself into the right mindset. I’m not a big planner like some people are — sometimes I like to let the project find its own way. But there’s also the real risk of getting lost in the details unless I rein myself in a little bit. I’m not alone in this tendency, of course. In the geek world, this is known as “yak shaving“.
The phrase comes obliquely from a Ren and Stimpy episode, and refers to common phenomenon where to get one thing done you have to first solve another problem. The second problem, of course, involves solving a third, and so on. So through this (potentially long) chain of dependencies, what looks like shaving a yak is obliquely working on cracking some actually relevant problem. Continue reading “Yak Shaving: Hacker Mode Vs Maker Mode”→
[CNLohr] just can’t get enough of the ESP8266 these days — now he’s working on getting a version of V-USB software low-speed USB device emulation working on the thing. (GitHub link here, video also embedded below.) That’s not likely to be an afternoon project, and we should warn you that it’s still a project in progress, but he’s made some in-progress material available, and if you’re interested either in USB or the way the mind of [CNLohr] works, it’s worth a watch.
In this video, he leans heavily on the logic analyzer. He’s not a USB expert, and couldn’t find the right resources online to implement a USB driver, so he taught himself by looking at the signals coming across as he wiggled a mouse on his desk. Using the ever-popular Wireshark helped him out a lot with this task as well. Then it was time to dig into Xtensa assembly language, because timing was critical.
Speaking of timing, one of the first things that he did was write some profiling routines so that he could figure out how long everything was taking. And did we mention that [CNLohr] didn’t know Xtensa assembly? So he wrote routines in C, compiled them using the Xtensa GCC compiler, and backed out the assembly. The end result is a mix of the two: assembly when speed counts, and C when it’s more comfortable.
I wanted to point out a tool that I often use, but rarely see on other people’s workbenches: thermal strippers. They aren’t cheap, but once you’ve used them, it is hard to go back to stripping wires with an ordinary tool.
I know, I know. When I first heard of such a thing, I thought what you are probably thinking now: maybe for some exotic coated wire, but for regular wire, I just use a pair of diagonal cutters or a mechanical stripper or a razor blade. You can do that, of course, and for large solid wires, you can even get good results. But for handling any kind of wire, regardless of size, you just can’t beat a thermal stripper.
Software defined radios are getting better and better all the time. The balaclava-wearing hackers know it, too. From what we saw at HOPE in New York a few weeks ago, we’re just months away from being able to put a femtocell in a desktop computer for under $3,000. In less than a year, evil, bad hackers could be tapping into your cell phone or reading your text message from the comfort of a van parked across the street. You should be scared, even though police departments everywhere and every government agency already has this capability.
These rogue cell sites have various capabilities, from being able to track an individual phone, gather metadata about who you have been calling and for how long, to much more invasive surveillance such as intercepting SMS messages and what websites you’re visiting on your phone. The EFF calls them cell-site simulators, and they’re an incredible violation of privacy. While there was most certinaly several of these devices at DEF CON, I only saw one in a hotel room (you catchin’ what I’m throwin here?).
No matter where the threat comes from, rogue cell towers still exist. Simply knowing they exist isn’t helpful – a proper defence against governments or balaclava wearing hackers requires some sort of detection system.. For the last few months [Eric Escobar] has been working on a simple device that allows anyone to detect when one of these Stingrays or IMSI catchers turns on. With several of these devices connected together, he can even tell where these rogue cell towers are.
A Stingray / cell site simulator detector
Stingrays, IMSI catchers, cell site simulators, and real, legitimate cell towers all broadcast beacons containing information. This information includes the radio channel number, country code, network code, an ID number unique to a large area, and the transmit power. To make detecting rogue cell sites harder, some of this information may change; the transmit power may be reduced if a tech is working on the site, for instance.
To build his rogue-cell-site detector, [Eric] is logging this information to a device consisting of a Raspberry Pi, SIM900 GSM module, an Adafruit GPS module, and a TV-tuner Software Defined Radio dongle. Data received from a cell site is logged to a database along with GPS coordinates. After driving around the neighborhood with his rogue-cell-site detector sitting on his dashboard, [Eric] had a ton of data that included latitude, longitude, received power from a cell tower, and the data from the cell tower. This data was thrown at QGIS, an open source Geographic Information System package, revealing a heatmap with the probable locations of cell towers highlighted in red.
This device really isn’t a tool to detect only rogue cell towers – it finds all cell towers. Differentiating between a rogue and legitimate tower still takes a bit of work. If the heatmap shows a cell site on a fenced-off parcel of land with a big tower, it’s a pretty good bet that cell tower is legit. If, however, the heatmap shows a cell tower showing up on the corner of your street for only a week, that might be cause for alarm.
Future work on this cell site simulator detector will be focused on making it slightly more automatic – three or four of these devices sprinkled around your neighborhood would easily allow you to detect and locate any new cell phone tower. [Eric] might also tackle triangulation of cell sites with an RF-blocking dome with a slit in it revolving around the GSM900 antenna.
The Scottish Consulate has stamped its last passport, the Dutch fire tower has belched its final flame, and the Gold Members Lounge has followed the Hacienda and the Marquee into clubland oblivion. EMF Camp 2016 is over, so all the 1500 or so attendees have left are the memories, photographs, and festival diarrhoea to remind them of their three days in the Surrey countryside.
Well, not quite all, there is the small matter of the badge.
The badge features an STM32L486VGT6 ARM Cortex M4 running at 80MHz, a 320×240 pixel colour LCD, magnetometer and accelerometer, and a CC3100 WiFi processor. The firmware provides a simple interface to an app store containing an expanding array of micropython apps from both the EMF Camp team and submitted by event attendees. As shipped the badge connects to one of the site networks, but this can be adjusted to your own network after the event. It’s been designed for ease of hacking, requiring only a USB connection and mounting as a disk drive without need for special software or IDE. A comprehensive array of I/O lines are brought out to both 0.1″ pitch pins and 4mm edge-mounted holes. At the EMF Camp closing speeches there was an announcement of a competition with a range of prizes for the best hardware and software uses for the badge.
As is so often the case the badge was not without its teething troubles, as the network coped with so many devices connecting at once and the on-board Neopixel turned out to have been mounted upside down. Our badge seemed to have a bit of trouble maintaining a steady network connection and apps frequently crashed with miscellaneous Python errors, though a succession of firmware updates have resulted in a more stable experience. But these moments are part of the badge experience; this is after all an event whose attendees are likely to have the means to cope with such problems.
All the relevant files and software for the badge are fully open-source, and can be found in the EMF Camp GitHub repositories. We’ve put a set of images of the board in a gallery below if you are curious. The pinout images are courtesy of the EMF badge wiki.
[TK] has a stretch goal for his RC car project — enabling it to recharge on solar power during the day and roam around under remote Internet control at night. It’s like a miniature, backyard version of NASA’s Curiosity rover.
Right now, he’s gotten a Raspberry Pi Zero and a camera on board, and has them controlling the robot over WiFi. He looks like he’s having a great time piloting it around his house. Check out the video down below for (crashy) remote-controlled operation.
We can’t wait to see if solar power is remotely possible (tee-hee!) as an option for this vehicle. The eventual plan to connect it via 3G cellular modem is still off in the future, and will probably demand more of the smarts of the Raspberry Pi than at present. But we love the idea of a long-running autonomous vehicle, so we’re pulling for you, [TK]!
