c0nrad's c0rner

RSC Flight Protocol

Fri, 13 Mar 2026 13:21:55 -0400

I’m currently building an app using Next.js ( dmarcdefender.io). I’m not sure how I feel about it (it being Next.JS, dmarcdefender is amazing). It’s both amazing and terrifying, seamlessly jumping between client-side and server-side code. I don’t really like magic, but it is nice having one single environment, one set of types, complete DRY across the client and server, and SSR/SSG for free.

Part of the magic is the Flight protocol. If you’ve ever inspected the network tab of a Next.js app, you’ve probably seen some gobbledygook:

Recursive Dns Resolver

Thu, 12 Mar 2026 12:55:59 -0400

Overview

Today’s project is to make yesterday’s stub resolver a recursive resolver. Specifically I want to start with the root.hints and go down the chain till I get the A record for c0nrad.io.

https://gist.github.com/c0nrad/8497352c18d27b93c67a530663335a55

Steps

Ask D.ROOT-SERVERS.NET (NASA) for the NS record of .io
Ask a0.nic.io for the NS of c0nrad.io
Ask ns-1089.awsdns-08.org for the A record of c0nrad.io

Learnings / Refreshers

13 DNS Root servers
- On ubuntu, you can view the seed /usr/share/dns/root.hints
By default, no additional data when getting the .com gtld-servers.net servers because the message size is greater than 512 bytes.
- I used the EDNS(0) OPT additional record to get 4092 bytes
In-Bailiwick vs. Out-of-Bailiwick
- “Bail” owner, “wick” city? In-zone response
- When querying a0.nic.io for NS of c0nrad.io, it returns ns-1089.awsdns-08.org, but no additional data with the A record of the NS. So you have to start a subquery.
- When querying D.ROOT-SERVERS.NET for the NS, it’ll staple the A records in the additional data.
When working with an API that has you register callbacks (client.onmessage(callbck)), and you want a send(message) -> response API, you can wrap the api in a new Promise(resolve, reject)

DNS Stub Resolver

Wed, 11 Mar 2026 09:46:29 -0400

I realized I haven’t done much learning in a while ( https://dmarcdefender.io is my current project, but it’s just standard SaaS work). So I figured I might try to spend an hour or two each day learning something new.

Today’s project was building a super simple DNS resolver. The goal was just to resolve the A record for c0nrad.io into an IP address.

Brainstorming Pathfinding Algorithms: QuadTree & RelaxPath

Tue, 02 Dec 2025 02:44:54 -0700

I had an idea for a fun “grid search” pathfinding algorithm for MIT battlecode, so decided to write a little playground in JS. This article covers the results.

SWU Card Reader Neural Net P1

Wed, 09 Jul 2025 18:08:34 -0400

New project! Using AI to read SWU card aspects.

I just finished a coursera course on Deep Learning and Neural Networks so figured I’d try to do something with my newfound knowledge!

In this project I’ll be building some NN (Neural Networks) manually that will take in a Star Wars Unlimited card image and determine if “isHeroic”, “isVillainous”, and “isNeutral” by reading the aspects on the top left.

At this point I only know how to do binary classifiers… so yes or no questions. So this will be part 1, in the future I should be able to ask more interesting questions of the models like “Who is the artist”, “How many resources does this card cost”, “what are the traits”, etc.

SWU Health Counter

Sat, 28 Jun 2025 15:30:24 -0400

A new electronics project! It’s a simple circuit that just keeps track of base health for Star Wars Unlimited (SWU) trading card game. This was my first time making/ordering a PCB, and I learned a lot along the way.

Problem Statement

To keep track of your base health in SWU, people usually use little damage tokens (in increments of 1/3/5/10), or dice. But I don’t like these.

Reasons to Not Be Hard on Yourself (CTFs)

Tue, 31 Dec 2024 16:04:30 -0500

Every once in a while I either get a Discord message or see a post about someone who is feeling down about not doing well on CTFs. To be honest, I also sometimes make the mistake of feeling down when I compare myself to others.

As we go into 2025, here are my opinions on why we both shouldn’t be too hard on ourselves.

1. CTFs are not “Real World” Security

Sim 7: A failed attempt at an exact critical temperature for 3D Ising

Wed, 16 Mar 2022 08:22:04 -0700

Sim 6: Ising Model Pt. 1

Tue, 25 Jan 2022 15:50:49 -0800

We build out a simple Ising model simulator for future expansion.

Sim 5: Wien's Law from Plank's Blackbody Radiation Formula using Sympy

Mon, 17 Jan 2022 13:40:45 -0800

We derive wien’s constant using plank’s blackbody radiation formula.

Sim 4: Clebsch-Gordan Coefficients

Wed, 29 Dec 2021 11:05:11 -0800

This post covers a script I wrote for generating the clebsch-gordan coefficients by scratch.

Sim 3: Kepler Problems

Wed, 22 Dec 2021 10:07:03 -0800

We solve for the different types of orbits of the Kepler Problem (two body central force problems).

Sim 2: Effective Potential

Sun, 19 Dec 2021 11:00:24 -0800

Plot the effective potential for the two body force simulation.

Sim 1: Two Body Central Force

Sun, 19 Dec 2021 05:24:02 -0700

Day one of building 99 simulations. We’ll reduce a problem that at first requires 6 parameters with coupling, to a problem with just 3 (or 2, depending on how you look at it) by exploiting the symmetry. “Nature does not care how we describe her”.

Slack LaTeX

Mon, 11 Oct 2021 17:44:54 -0700

I had fun building a new product with my partner called Slack LaTeX. It’s a slack app for embedding formatted equations (through LaTeX). This post covers some of the motivation and some of the fun technical architecture design decisions.

Quantum Circuit Editor Pt. 1

Tue, 10 Aug 2021 09:31:09 -0700

Initial version of a quantum circuit editor.

Prime Walker

Sat, 24 Jul 2021 22:23:16 -0700

Another attempt at a factoring algorithm.

Randomized Benchmarking of a noisy quantum simulator Pt. 1

Thu, 22 Jul 2021 22:18:37 -0700

This post covers the simplest of error models and some simulated randomized benchmarking results.

Density Operators

Tue, 20 Jul 2021 21:24:02 -0700

This post covers my transition from using pure states to mixed states in my quantum simulator.

Mulbrute

Sun, 28 Feb 2021 11:04:32 -0500

QHack 2021 submission project, a tool for brute forcing quantum multiplication circuits.

Plasma Leak

Mon, 18 Jan 2021 15:25:22 -0500

Plasma leak the game.

Laplace's/Poisson's Equation via Method Of Relaxation

Mon, 11 Jan 2021 11:10:40 -0500

Solving Laplace’s/Poisson’s equation using the method of relaxation.

Thermoshat Pt. 3

Fri, 08 Jan 2021 16:29:21 -0500

Setting up a metrics endpoint for thermoshat.

Thermoshat Pt. 2

Thu, 07 Jan 2021 14:38:37 -0500

Updates and finalizing the thermoshat project.

Thermoshat Pt. 1

Tue, 05 Jan 2021 10:12:00 -0500

Introducing the thermoshat. A raspberry pi to adjust my manual thermostat with the added of thrill of increased fire danger.

Feynman Diagram Editor Pt 2

Tue, 20 Oct 2020 20:37:28 -0400

It’s alive! https://blog.c0nrad.io/feynman

Feynman Diagram Editor Pt. 1

Sat, 17 Oct 2020 12:29:59 -0400

Starting a new project for validating Feynman diagrams.

Independent Study

Thu, 15 Oct 2020 10:24:08 -0400

Thinking out loud about my future.

Effective Nuclear Charge Calculations

Mon, 12 Oct 2020 21:43:23 -0400

A smaller project involving plotting ionization energy for different effective nuclear charge models.

SO(3) Lie Group Generators via Brute Force

Sat, 03 Oct 2020 19:39:08 -0400

Brute forcing the generators for SO(3).

EM Particle Motion

Wed, 30 Sep 2020 17:26:11 -0400

Simulating a particle under the influence. (Of electric and magnetic fields).

Klein Gordon Eqn via Connected Springs

Sat, 12 Sep 2020 14:35:23 -0400

Simulations Klein Gordon Eqn as a set of connected springs.

Spherical Bug

Wed, 09 Sep 2020 09:16:42 -0400

Discussion of one of my longest living software bugs.

Scattering Angles

Sun, 30 Aug 2020 12:14:51 -0400

Calculating scattering angles from fully elastic spherical collision.

Hydrogen Spectral Diagram

Sat, 29 Aug 2020 10:59:09 -0400

Terminal application showing the spectral lines for electron transitions in hydrogen.

Interference

Tue, 18 Aug 2020 18:53:54 -0400

Double Slit Interference Pattern demo.

Matrix Inversion

Fri, 07 Aug 2020 18:37:01 -0400

Some fun inverting matrixes.

Vector Calculus Part 3: Electric Dipole

Tue, 21 Jul 2020 18:37:01 -0400

More fun with vector calc/electromagnetism.

Vector Calculus Part 2: Visualization

Mon, 20 Jul 2020 21:04:09 -0400

Playing with three.js to do some vector visualizations.

Vector Calculus

Sun, 19 Jul 2020 10:10:01 -0400

Progress on a vector calculus library in javascript.

Numerical Integration

Sat, 11 Jul 2020 23:12:13 -0400

Some exploration into numerical integration.

Numerical Differentiation

Fri, 10 Jul 2020 20:01:46 -0400

Some exploration into numerical differentiation.

Shor's Algorithm

Fri, 10 Jul 2020 09:26:38 -0400

Shor’s algorithm is probably the most well known quantum algorithm. But it turns out I didn’t understand it as well as I thought.

Simulating Quantum Fourier Transform

Tue, 07 Jul 2020 11:01:25 -0400

I’m pretty excited. I’m somewhat in disbelief that it even works. But I was able to implement Quantum Fourier Transform on my little quantum computation simulator.

Quantum Teleportation Algorithm

Fri, 03 Jul 2020 13:24:22 -0400

This post is split into two parts. The first section is my motivation, and some background on the upgrades I made to my quantum simulator. The second part is implementing the Quantum Teleportation algorithm.

Florida

Mon, 29 Jun 2020 12:06:58 -0400

We moved to Florida! Made a little video.

Electron Wavefunctions for Hydrogen Part 2

Sat, 20 Jun 2020 14:37:31 -0400

Part 2 of calculating the electron wavefunctions for hydrogen.

View Visualization

Reflections on 6 months solo SaaS startup

Tue, 16 Jun 2020 07:59:02 -0400

It’s crazy to think my startup is already over 6 months old. This post is some informal reflections on that period.

Electron Wavefunctions for Hydrogen Part 1

Thu, 28 May 2020 10:22:30 -0400

The code/math behind calculating the electron wavefunctions for hydrogen.

GiNaC on Macos

Wed, 27 May 2020 18:43:40 -0400

A quick guide on getting started with GiNaC on macos.

Quantum Infinite Well

Fri, 22 May 2020 12:30:26 -0400

Calculating the stationary states of an electron in a quantum infinite well.

Calculating Collisions Pt. 2

Mon, 18 May 2020 12:30:26 -0400

Programming the equation we derived in the last post.

Calculating Collisions

Fri, 17 May 2019 00:00:00 +0000

My attempt at calculating the resulting velocities of two spheres colliding in 3D.

Mon, 01 Jan 0001 00:00:00 +0000