Daniel Wang danielwangksu

hi, i'm daniel. i'm a 15-year-old with some programming experience and i do a little bug hunting in my free time. here's the insane story of how I found a single bug that affected over half of all Fortune 500 companies:

say hello to zendesk

If you've spent some time online, you’ve probably come across Zendesk.

Zendesk is a customer service tool used by some of the world’s top companies. It’s easy to set up: you link it to your company’s support email (like [email protected]), and Zendesk starts managing incoming emails and creating tickets. You can handle these tickets yourself or have a support team do it for you. Zendesk is a billion-dollar company, trusted by big names like Cloudflare.

Personally, I’ve always found it surprising that these massive companies, worth billions, rely on third-party tools like Zendesk instead of building their own in-house ticketing systems.

your weakest link

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

GROKKING NOTES

I liked the way Grokking the coding interview organized problems into learnable patterns. However, the course is expensive and the majority of the time the problems are copy-pasted from leetcode. As the explanations on leetcode are usually just as good, the course really boils down to being a glorified curated list of leetcode problems.

So below I made a list of leetcode problems that are as close to grokking problems as possible.

Pattern: Sliding Window

OpenSSL Cheat Sheet 🔐

Install

Install the OpenSSL on Debian based systems

sudo apt-get install openssl

Nginx Reverse Proxy for homelab services using SSO

NOTE: This document has now been added to the nginx-sso wiki, here. Any further updates will be made there.

Using:

Docker
Nginx
nginx-sso

Usage

export MACOS_UNIVERSAL=no
pip install capstone # or something depends on capstone

Fore more detail...

Refer to this issue: capstone-engine/capstone#1235

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

	#!/bin/bash

	# Dependencies
	# tpm2-tools-4.0.1-1.fc31.x86_64
	# tpm2-tss-2.3.1-1.fc31.x86_64
	# tpm2-tss-engine-master

	set -euxo pipefail

	export TPM2TOOLS_TCTI="device:/dev/tpmrm0"

	# Kernel sysctl configuration file for Linux
	#
	# Version 1.14 - 2019-04-05
	# Michiel Klaver - IT Professional
	# http://klaver.it/linux/ for the latest version - http://klaver.it/bsd/ for a BSD variant
	#
	# This file should be saved as /etc/sysctl.conf and can be activated using the command:
	# sysctl -e -p /etc/sysctl.conf
	#
	# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and sysctl.conf(5) for more details.

	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <string.h>
	#include <unistd.h>
	#include "config.h"
	#include "test.h"
	#if HAVE_OPENSSL_SHA_H