Hackaday Podcast 168: Math Flattens Spheres, FPGAs Emulate Arcades, And We Can’t Shake Polaroid Pictures

May 13, 2022 by Dan Maloney 5 Comments

Join Hackaday Editor-in-Chief Elliot Williams and Staff Writer Dan Maloney as they review the top hacks for the week. It was a real retro-fest this time, with a C64 built from (mostly) new parts, an Altoids Altair, and learning FPGAs via classic video games. We also looked at LCD sniffing to capture data from old devices, reimagined the resistor color code, revisited the magic of Polaroid instant cameras, and took a trip down television’s memory lane. But it wasn’t all old stuff — there’s flat-packing a sphere with math, spraying a fine finish on 3D printed parts, a DRM-free label printer, and a look at what’s inside that smartphone in your pocket — including some really weird optics.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments below!

Direct Download link.

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This Week In Security: F5 Twitter PoC, Certifried, And Cloudflare Pages Pwned

May 13, 2022 by Jonathan Bennett 7 Comments

F5’s BIG-IP platform has a Remote Code Execution (RCE) vulnerability: CVE-2022-1388. This one is interesting, because a Proof of Concept (PoC) was quickly reverse engineered from the patch and released on Twitter, among other places.

Let's drop CVE-2022-1388 PoC pic.twitter.com/MmyvQGL6eO

— 416e6e61 (@AnnaViolet20) May 9, 2022

HORIZON3.ai researcher [James Horseman] wrote an explainer that sums up the issue nicely. User authentication is handled by multiple layers, one being a Pluggable Authentication Modules (PAM) module, and the other internally in a Java class. In practice this means that if the PAM module sees an X-F5-Auth-Token, it passes the request on to the Java code, which then validates the token to confirm it as authentic. If a request arrives at the Java service without this header, and instead the X-Forwarded-Host header is set to localhost, the request is accepted without authentication. The F5 authentication scheme isn’t naive, and a request without the X-F5-Auth-Token header gets checked by PAM, and dropped if the authentication doesn’t check out.

So where is the wiggle room that allows for a bypass? Yet another HTTP header, the Connection header. Normally this one only comes in two varieties, Connection: close and Connection: keep-alive. Really, this header is a hint describing the connection between the client and the edge proxy, and the contents of the Connection header is the list of other headers to be removed by a proxy. It’s essentially the list of headers that only apply to the connection over the internet. Continue reading “This Week In Security: F5 Twitter PoC, Certifried, And Cloudflare Pages Pwned” →

Can You Help NASA Build A Mars Sim In VR?

May 12, 2022 by Zoe Skyforest 40 Comments

No matter your project or field of endeavor, simulation is a useful tool for finding out what you don’t know. In many cases, problems or issues aren’t obvious until you try and do something. Where doing that thing is expensive or difficult, a simulation can be a low-stakes way to find out some problems without huge costs or undue risks.

Going to Mars is about as difficult and expensive as it gets. Thus, it’s unsurprising that NASA relies on simulations in planning its missions to the Red Planet. Now, the space agency is working to create a Mars sim in VR for training and assessment purposes. The best part is that you can help!

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With Rocket Lab’s Daring Midair Catch, Reusable Rockets Go Mainstream

May 12, 2022 by Tom Nardi 34 Comments

We’ve all marveled at the videos of SpaceX rockets returning to their point of origin and landing on their spindly deployable legs, looking for all the world like something pulled from a 1950s science fiction film. On countless occasions founder Elon Musk and president Gwynne Shotwell have extolled the virtues of reusable rockets, such as lower operating cost and the higher reliability that comes with each booster having a flight heritage. At this point, even NASA feels confident enough to fly their missions and astronauts on reused SpaceX hardware.

Even so, SpaceX’s reusability program has remained an outlier, as all other launch providers have stayed the course and continue to offer only expendable booster rockets. Competitors such as United Launch Alliance and Blue Origin have teased varying degrees of reusability for their future vehicles, but to date have nothing to show for it beyond some flashy computer-generated imagery. All the while SpaceX continues to streamline their process, reducing turnaround time and refurbishment costs with each successful reuse of a Falcon 9 booster.

But that changed earlier this month, when a helicopter successfully caught one of Rocket Lab’s Electron boosters in midair as it fell back down to Earth under a parachute. While calling the two companies outright competitors might be a stretch given the relative sizes and capabilities of their boosters, SpaceX finally has a sparing partner when it comes to the science of reusability. The Falcon 9 has already smashed the Space Shuttle’s record turnaround time, but perhaps Rocket Lab will be the first to achieve Elon Musk’s stated goal of re-flying a rocket within 24 hours of its recovery.

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Animate Your Robot In Blender

May 11, 2022 by Anne Ogborn 10 Comments

You’ve built a robot crammed full of servos and now you settle down for the fun part, programming your new dancing animatronic bear! The pain in your life is just beginning. Imagine that you decide the dancing bear should raise it’s arm. If you simply set a servo position, the motor will slew into place as fast as it can. What you need is an animation, and preferably with smooth acceleration.

You could work through all the math yourself. After half an hour of fiddling with the numbers, the bear is gracefully raising it’s arm like a one armed zombie. And then you realize that the bear has 34 more servos.

Fortunately for everybody who’s done the above, there’s Blender. It’s all about creating smooth motion for animations and computer graphics. Making robot motion with Blender is, if not easy, at least tolerable. We made a sample project, a 3-axis robot arm to illustrate. It has a non-moving pedestal, rotating base, upper arm, and lower arm. We’ll be animating it first in Blender and then translating the file over to something we can use to drive the servos with a little script.

Now, Blender is notorious for a difficult user interface. The good news is that, with revision 2.9, it moved to a much more normal interface. It still definitely is a large program, with 23 different editors and literally thousands of controls, but we’ll only be using a small subset to make our robot move. We won’t teach you Blender here, because there are thousands of great Blender tutorials online. You want to focus on animation, and the Humane Rigging series is particularly recommended.

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Bare-Metal STM32: Using The I2C Bus In Master-Transceiver Mode

May 11, 2022 by Maya Posch 34 Comments

As one of the most popular buses today for on- and inter-board communication within systems, there’s a good chance you’ll end up using it with an embedded system. I2C offers a variety of speeds while requiring only two wires (clock and data), which makes it significantly easier to handle than alternatives, such as SPI. Within the STM32 family of MCUs, you will find at least one I2C peripheral on each device.

As a shared, half-duplex medium, I2C uses a rather straightforward call-and-response design, where one device controls the clock, and other devices simply wait and listen until their fixed address is sent on the I2C bus. While configuring an STM32 I2C peripheral entails a few steps, it is quite painless to use afterwards, as we will see in this article. Continue reading “Bare-Metal STM32: Using The I2C Bus In Master-Transceiver Mode” →

Data Alignment Across Architectures: The Good, The Bad And The Ugly

May 10, 2022 by Maya Posch 19 Comments

Even though a computer’s memory map looks pretty smooth and very much byte-addressable at first glance, the same memory on a hardware level is a lot more bumpy. An essential term a developer may come across in this context is data alignment, which refers to how the hardware accesses the system’s random access memory (RAM). This and others are properties of the RAM and memory bus implementation of the system, with a variety of implications for software developers.

For a 32-bit memory bus, the optimal access type for some data would be a four bytes, aligned exactly on a four-byte border within memory. What happens when unaligned access is attempted – such as reading said four-byte value aligned halfway into a word – is implementation defined. Some hardware platforms have hardware support for unaligned access, others throw an exception that the operating system (OS) can catch and fallback to an unaligned routine in software. Other platforms will generally throw a bus error (SIGBUS in POSIX) if you attempt unaligned access.

Yet even if unaligned memory access is allowed, what is the true performance impact? Continue reading “Data Alignment Across Architectures: The Good, The Bad And The Ugly” →