usb drive

7 Articles

Infotainment system playing back from USB. (Folkert van Heusden)

Create Virtual USB Sticks With A Raspberry Pi Zero

March 9, 2024 by 28 Comments

Playing back music files from USB sticks is a common feature these days, and is built-into the infotainment system in [Folkert van Heusden]’s Opel Astra. Unfortunately such USB playback features often come with a range of limitations on things like audio codecs, and in the case of [Folkert]’s car, a 1000 file limit. This had him looking at an alternative to lugging a lot of USB sticks around to avoid the horror of hearing the same songs within a week while commuting. The solution? Make a Raspberry Pi Zero into a virtual USB mass storage device using the Mass Storage Gadget (MSG) driver in the Linux kernel.

Picking USB storage as the ideal option here comes mostly from the age of the infotainment system, which lacks Bluetooth, and the audio input jack is rather crackly. Of course, having the Raspberry Pi Zero pretend to be a storage device via the MSG driver wouldn’t solve the file limit, but to get around this two Python scripts were written: one which creates images from a folder of music files, and another which randomly picks one of the available images from the Zero’s SD card and configures the MSG driver to use it.

As for the list of future improvements, there is mounting the RPi Zero’s SD card as read-only to deal with the power-off when the car is shut down, and the creating of images requires to be run as root due to the use of loopback devices. As a Proof-of-Concept it does seem to be on the right track.

It’s not just the older infotainment systems that get to have all the fun. If you’re lucky enough to have Linux running in the dashboard, you might be little more than a Bash script away from bending the system to your will.

Updated OSHW Flash Drive Keeps Data Safe, Fingers Dry

June 14, 2023 by 27 Comments

For almost a year now, we’ve been following the progress [Walker] has been making with Ovrdrive — a completely open source USB flash drive that features the ability to destroy itself should it fall into the wrong hands. It’s an interesting enough project on those merits alone, but what really made this idea stand out was that the user was expected to lick their fingers before handling the drive as a form of covert authentication.

Well, we’ve got some good news and some bad news. The good news is that [Walker] is just about ready to release the Ovrdrive officially on Crowd Supply. But it’s with a heavy heart that we must report that the device’s cutting edge spit-detection capabilities have been removed. Now if you want to preserve the drive’s files, you need to rapidly insert and remove the drive several times rather than just plugging it in.

In all seriousness, this new approach makes a lot more sense. As entertaining as it might have been, the whole idea of a device that could detect moisture on the user’s fingers was fraught with problems. It was a bit more of a meme than a real solution, and if we’re being honest, kind of disgusting. This new approach sounds far more reliable, especially when combined with the new “Lite” self-destruct mode.

While the original capability of literally frying the flash chip by way of several capacitors and a voltage doubler is still here, there’s also a non-destructive approach that’s enabled by default. Unless you open up the drive and desolder the jumper pad on the PCB, the onboard ATtiny24A will simply use the enable pin on the flash chip to make it appear empty. This means that you’ve got to really want to cook your flash chip on the first hint of funny business.

Ultimately, whether it’s self-destructing or not, we just really like the idea of a hacker-developed open source hardware USB flash drive. Admittedly it would be a lot cheaper and more practical to just buy one like a normal person, but we strongly believe that if there’s a way for the community to build a OSHW version of something, they should at least give it a shot.

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The Spit-Detecting USB Flash Drive Is Nearly Here

December 25, 2022 by 17 Comments

Regular readers may recall that security researcher and general open source hardware fanatic [Walker] has been planning a rather unusual flash drive for some time — one that will only show its contents if the user makes sure to lick their fingers before plugging it in. We’re pleased to report that theory has recently given way to real hardware, and the Ovrdrive “self-destructing” flash drive is now a step closer to reality.

The last time we checked in with [Walker], he hadn’t yet put any hardware together, though he was fairly sure what components he would need and how it would all go together. This was assisted somewhat by the fact that USB flash drives are such a ubiquitous piece of tech, making their principle parts plentiful and fairly well documented. As explained in the video below, all you really need to spin up your own flash drive is the USB connector, the controller chip, and a nice slab of flash memory for it to access. Though naturally you’re on your own for spit detection.

The build video has some gorgeous camera work.

What we especially like about this project is that [Walker] is releasing the whole thing as open source hardware. So even if you’re not interested in the whole lick-for-access feature, you’ve still got a boilerplate flash drive design to build on. We haven’t seen a lot of DIY projects tackle USB Mass Storage previously, and perhaps this design can change that.

But of course, only if the thing works. According to the video after the break, [Walker] seems to have hit a snag with this revision of the hardware. While it enumerates as a storage device when plugged into the computer, the operating system claims its capacity is zero. He thinks there might be a swapped trace between the controller and flash chip to blame, so hopefully he can get things sorted out before too long. We’ve been covering this project since the summer, and are eager to see it cross the finish line.

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So How Do You Make A Self-Destructing Flash Drive?

September 26, 2022 by 57 Comments

A self-destructing storage device that vaporizes its contents at the first sign of trouble would be an invaluable tool for many people, but good luck getting your hands on such a thing if you don’t work for a three-letter agency. Or at least, that’s what we would have said before [Walker] got on the case. He’s working on an open source self-destructing USB flash drive for journalists, security researchers, whistleblowers, or anyone else who really values their privacy.

When we previously covered this project in July, [Walker] had only planned to make the flash drive hide its contents unless you knew to wet your fingers before plugging it in. We admit it sounds a little weird, but as far as clandestine methods of activating something goes, it’s pretty clever. But based on the feedback he received, he decided to go all-in and make the USB drive literally trash itself should it be accessed by somebody who doesn’t know the secret.

An elegant weapon for a more civilized age.

But how exactly do you pull that off? Sure we’d love to see a small thermite charge or vial of acid packed in there, but obviously that’s not very practical. It needs to be safe to carry around, and just as importantly, unlikely to get you into even more trouble with whoever is searching through your belongings. To that end, [Walker] thinks he’s come up with an elegant solution.

The datasheet for his flash memory chip says the maximum voltage it can handle before releasing the Magic Smoke is a meager 4.6 V. So he figures running a voltage doubler on the nominal 5 V coming from a USB port should disable the chip nicely with a minimum of external drama. Will it be enough to prevent the data from being recovered forensically? We don’t know, but we’re eager to find out.

In the write-up, [Walker] takes readers through the circuit designs he’s come up so far, and shows off the source code that will run on the ATtiny25 to determine when it’s time to toast the flash. He says by the next post he should have the entire flash drive built and documented, so stay tuned.

USB Drive Keeps Your Secrets… As Long As Your Fingers Are Wet?

July 30, 2022 by 27 Comments

[Walker] has a very interesting new project: a completely different take on a self-destructing USB drive. Instead of relying on encryption or other “visible” security features, this device looks and works like an utterly normal USB drive. The only difference is this: if an unauthorized person plugs it in, there’s no data. What separates authorized access from unauthorized? Wet fingers.

It sounds weird, but let’s walk through the thinking behind the concept. First, encryption is of course the technologically sound and correct solution to data security. But in some environments, the mere presence of encryption technology can be considered incriminating. In such environments, it is better for the drive to appear completely normal.

Toggling the chip enable (CE) pin will hide the drive’s contents.

The second part is the access control; the “wet fingers” part. [Walker] plans to have hidden electrodes surreptitiously measure the resistance of a user’s finger when it’s being plugged in. He says a dry finger should be around 1.5 MΩ, but wet fingers are more like 500 kΩ.

But why detect a wet finger as part of access control? Well, what’s something no normal person would do right before plugging in a USB drive? Lick their finger. And what’s something a microcontroller should be able to detect easily without a lot of extra parts? A freshly-licked finger.

Of course, detecting wet skin is only half the equation. You still need to implement a USB Mass Storage device, and that’s where things get particularly interesting. Even if you aren’t into the covert aspect of this device, the research [Walker] has done into USB storage controllers and flash chips, combined with the KiCad footprints he’s already put together means this open source project will be a great example for anyone looking to roll their own USB flash drives.

Regular readers may recall that [Walker] was previously working on a very impressive Linux “wall wart” intended for penetration testers, but the chip shortage has put that ambitious project on hold for the time being. As this build looks to utilize less exotic components, hopefully it can avoid a similar fate.

A Very Buttoned Up Raspberry Pi Media Server

February 7, 2020 by 21 Comments

Projects that turn the Raspberry Pi into a low-cost Network Attached Storage (NAS) solution are very common; all you need is the right software, the Pi itself, and some USB storage devices. But unless you particularly like the “Medusa” look, with loose cables running all over the place, you’ll probably want to put the hardware into a suitable enclosure. Unfortunately, that’s where the somewhat unusual layout of the Pi can make things tricky.

Which is why [AraymBox] came up with this unique “capsule” enclosure for the Raspberry Pi and two USB-attached hard drives. Every effort has been made to keep the outside of this design as clean and streamlined as possible. The asymmetrical loops of wires that we so often see on other projects are gone, with everything been brought inside thanks to some clever wiring. This enclosure looks like a professional product, and if you’re willing to put in the effort, you can have one to call your own.

The good news is that the 3D printed enclosure only has four parts, albeit rather large ones, and none of which require support material. So it should be an easy print even on a relatively low-end machine. Of course, you’re not going to get that futuristic metallic look without a little work. You’ll need to do a considerable amount of sanding, filling, and paint work to get that kind of a surface finish. Then again, that rough “just printed” look has a certain cyberpunk appeal to it as well.

But the printed enclosure is only half the battle. Inside, [AraymBox] has soldered the USB to SATA adapter cables directly to the Raspberry Pi to keep things tight and compact. A micro USB breakout board was then used to add a power connector on the back of the device where the Ethernet and USB ports are, solving the issue of having one lonely USB cable coming out of the side of the case.

In the past we’ve seen other attempts to create a 3D printable enclosure for Pi servers, with varying levels of success. While some would argue that the better solution is to just throw the Pi and the drives in a large enough enclosure that it doesn’t matter what the wiring looks like, we appreciate the effort that some hackers are willing to put in to make something custom.

Dead HDD Smartphone Stand Still Holds Secret Data

March 21, 2012 by 17 Comments

We’ve actually got a few dead hard drives collecting dust so when we hear about a project that finds a use for one we perk up a bit. But we were somewhat disappointed when we discovered this was a smartphone stand, pen holder, and LED lamp in one. We just don’t have a use for this kind of triple-tasker. But wait… the dead drive has a secret. It still serves as data storage, if you know how to enabling the drive within.

As you can seen, [Samimiy] removed all the guts of the HDD, repurposing the platters and mounting brackets as the phone holder, and mounting plate for a couple handfuls of LEDs. The lamp portion can be adjusted thanks to the articulated based from a small desk lamp he had in his parts bin. The device receives power from the USB connector you can see in the upper right. That’s where the first part of the secret comes in. This isn’t just supplying power, it provides a USB connection to the thumb drive hidden inside the HDD case. But just connecting it to your computer won’t mount it. [Samimy] took the light sensor from an automatic nightlight and set it up below the pen holder. If you shine a flashlight down the hole in that piece of wood it will routed power to the secret USB drive causing it to enumerate on your system. Pretty clever! Take a look at his build video after the break.

We wonder if there’s a way to incorporate this light-based lock system into that mouse-mounted thumb drive.

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