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Showing posts from March, 2019

pixel_lang 3: Showcase

I'd like to take a little time today to showcase some of the programs I made with pixel_lang. I'm very proud of them, and I'm hoping someone will enjoy watching and dissecting them.

The first one I'd like to show off is my Ackermann function, which uses forking, and it's own in-memory call stack to orchestrate all the individual pistons to fire when necessary.

In the example above, there are three possible decisions made, if M is equal to 0, if N is equal to 0, and the recursive call, with the n-arg. That's why the fork splits the piston into three, one for the recursive call itself, and one for the n-arg, which is also a recursive call.

Here is the draft version of the function, that I made by hand with comments.


Since each call to ack() waits for the next call to finish, I created a basic lock system, that tests to see if there is a piston still executing the function. When a piston finishes, it either creates new pistons (the recursive n-arg call), or frees …

Besder - An Investigative Security Journey Announcement

Hello everyone!

I recently bought a new network camera from a company called Besder. I'll be tearing it down and showing some cool new stuff soon. Lots of work to be done but, I'm already making progress!



Really excited to show off some new content!

pixel_lang 2: Basic Instructions

We covered Start, End, and Output Char in the last section, next we want to use Direction and Jump. Let's create a version of Hello World that does some crafty maneuvering to only use a single output char instruction for each character of "Hello World!". First we need to make the instructions we need to use.

Check out Part 1!

Then we just need to come up with an interesting layout. I had to specifically be aware of the OutputChar L, because it's used three times, and I need to go a different route each time.


I often times use Jump to allow a single directional line of code have multiple meanings.

For example, take this program, which only hits the pink spaces one way, and the yellow spaces other. This programs runs indefinitely.

Insert Insert is instruction number 0x8, and it's 20bit argument is stacked onto the I stack of any Piston that executes it. It's used to introduce constants into your program.
Move Move is an instruction which takes two register ar…

pixel_lang 1: Introduction

Today I'm really excited to start a new series on pixel_lang, a pixel-based 2D esoteric language I wrote myself in Crystal. I've always really loved esoteric languages, and they can teach us a lot about programming. I enjoy the aspect of honing one's programming chops, and esoteric languages are filled with all sorts of interesting challenges. My goal in writing an esoteric language was to make a language with a large instruction set, that could be used to make art, programs, or some combination of the two.



You can find all project files located on the GitHub.

The purpose of this article, is to give a basic introduction on how to use the pixel_lang interpreter, as well as the web interface, to load and run programs, as well as a basic explanation of how the system works.

The pixel_lang interpreter takes an input PNG file, and uses that as it's program code. Each pixel in the PNG is read in, and stored into a 2D array of instructions. Any and all PNG files are valid pro…

VStarCam - An Investigative Security Journey - Part 2

In the last part, I covered the basics of the UDP protocol used by the camera, as well as some of the quirks and potential problems. In this part, we will be looking at finishing up the UDP protocol, and using it to exploit the Android client, revealing the password of the device, as well as attempting to upload a custom firmware to the camera.
Theory-crafting A Vulnerability Now that we are at the point of near 100% protocol coverage, we can start to think about some ways that we could potentially abuse the protocol, and the devices behind them. One thing I noticed after completely tearing down every packet in the connection process, was that all the information needed to impersonate the camera is sent to broadcast. This means that even when connected directly through LAN, the camera could potentially be impersonated by anyone on the same subnet. A couple things also hint at this.
The IP address of the camera can change, and the client must be able to respond to this change.This means …