terjanq

Postviewer - writeup

Challenge's overview

The rumor tells that adm1n stores their secret split into multiple documents. Can you catch 'em all? https://postviewer-web.2022.ctfcompetition.com

The challenge consisted of an all client-side simple page, i.e. no backend code was involved. A user can upload any file which will be then locally stored in indexedDB. They can preview their files by either clicking on the title or by visiting file's URL, for example https://postviewer-web.2022.ctfcompetition.com/#file-01d6039e3e157ebcbbf6b2f7cb2dc678f3b9214d. The preview of the file is rendered inside a blob created from data: URL. The rendering occurs by sending file's contents to the iframe via postMessage({ body, mimeType }, '*')

Additionally, there is a /bot endpoint which lets players send URLs to an xss-bot imitating another user. The goal is to steal their documents.

EllyLoel

/*
  Made by Elly Loel - https://ellyloel.com/
  With inspiration from:
    - Josh W Comeau - https://courses.joshwcomeau.com/css-for-js/treasure-trove/010-global-styles/
    - Andy Bell - https://piccalil.li/blog/a-modern-css-reset/
    - Adam Argyle - https://unpkg.com/open-props@1.3.16/normalize.min.css / https://codepen.io/argyleink/pen/KKvRORE

  Notes:
    - `:where()` is used to lower specificity for easy overriding.
*/

steve8708

const minute = 60;
const hour = minute * 60;
const day = hour * 24;
const week = day * 7;
const month = day * 30;
const year = day * 365;

/**
 * Convert a date to a relative time string, such as
 * "a minute ago", "in 2 hours", "yesterday", "3 months ago", etc.

anuraghazra

In these two files if you change getToken{slow,fast}'s passed value (just add a random letter anywhere) you'll see that the fast version is getting type checked about 3x to 5x faster than the slow one.

I'm not sure why using key remapping and using keyof {} is about 3x to 5x faster when doing type checking.

My guess is that in the slow version is using index access with the {}[keyof Theme] which is generally slower?

• Slow version: https://tsplay.dev/WJ4bRN
• Fast version: https://tsplay.dev/w24J4m

davidfowl

Minimal APIs at a glance

This document now exists on the official ASP.NET core docs page.

• Application
  • WebApplication
  • WebApplicationBuilder
• Request Handling
  • Routing
  • Parameter Binding

davidfowl

using System.Buffers;
using System.Net.WebSockets;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/ws", async (HttpContext context) =>
{
    const int MaxMessageSize = 1024 * 1024;

yyx990803

// example vite.config.js
import { cdn } from './vite-plugin-cdn'

export default {
  plugins: [
    // also supported: esm.run, jspm
    // loads the dep over the CDN during dev
    // auto downloads and includes into the bundle during build
    cdn('skypack', {
      vue: '^3.0.5'

rikschennink

export default (element: HTMLElement, options: any = {}) => {
    // if added as action on non focusable element you should add tabindex=0 attribute

    const {
        direction = undefined,
        shiftMultiplier = 10,
        bubbles = false,
        stopKeydownPropagation = true,
    } = options;

tannerlinsley

Replacing Create React App with the Next.js CLI

How dare you make a jab at Create React App!?

Firstly, Create React App is good. But it's a very rigid CLI, primarily designed for projects that require very little to no configuration. This makes it great for beginners and simple projects but unfortunately, this means that it's pretty non-extensible. Despite the involvement from big names and a ton of great devs, it has left me wanting a much better developer experience with a lot more polish when it comes to hot reloading, babel configuration, webpack configuration, etc. It's definitely simple and good, but not amazing.

Now, compare that experience to Next.js which for starters has a much larger team behind it provided by a world-class company (Vercel) who are all financially dedicated to making it the best DX you could imagine to build any React application. Next.js is the 💣-diggity. It has amazing docs, great support, can grow with your requirements into SSR or static site generation, etc.

So why

ld100

Migrating from Ubuntu on WSL to ArchLinux on WSL2

Obsolete notice

This document was created back in 2020 and might not be actual nowadays. It is not supported anymore, so use thise information at your own risk.

Upgrading to WSL 2

• Download WSL2 Kernel
• run wsl --set-default-version 2 in windows command line, so that all future WSL machine will use WSL2.