Javier Marquez arqex

Cryptographic Best Practices

Putting cryptographic primitives together is a lot like putting a jigsaw puzzle together, where all the pieces are cut exactly the same way, but there is only one correct solution. Thankfully, there are some projects out there that are working hard to make sure developers are getting it right.

The following advice comes from years of research from leading security researchers, developers, and cryptographers. This Gist was [forked from Thomas Ptacek's Gist][1] to be more readable. Additions have been added from

TLDR: a React component should either manage its own state, or expose a callback so that its parent can. But never both.

Sometimes our first impulse is for a component to entirely manage its own state. Consider this simple theater seating picker that has a letter for a row, and a number for a seat. Clicking the buttons to increment each value is hardly the height of user-interface design, but never mind - that's how it works:

/* @flow */
var React = require('react');

var Letter: React.ReactClass = React.createClass({
  getInitialState: function(): any {

The Problem

Standard practices say no non-root process gets to talk to the Internet on a port less than 1024. How, then, could I get Node talking on port 80 on EC2? (I wanted it to go as fast as possible and use the smallest possible share of my teeny tiny little micro-instance's resources, so proxying through nginx or Apache seemed suboptimal.)

The temptingly easy but ultimately wrong solution:

Alter the port the script talks to from 8000 to 80:

}).listen(80);

	#!/bin/bash
	#
	# Create a RN project which includes react-native-web
	# Takes one argument, the target directory (and app) name,

	if [ $# -ne 1 ]
	then
	echo "usage: $0 <target-dir>"
	exit 1
	fi

	var React = require("react"), Dom = React.DOM;
	var LogOutButton = require('./src/logout');
	var events = require('api/events');

	var Main = React.createClass({
	// this mixin provides this.emitLogout, and if we set onLogout it'll be called when "logout" is emitted
	mixins: [events.mixinFor("logout")],

	getInitialState: function(){
	return {

	// NOTE: I previously suggested doing this through Grunt, but had plenty of problems with
	// my set up. Grunt did some weird things with scope, and I ended up using nodemon. This
	// setup is now using Gulp. It works exactly how I expect it to and is WAY more concise.
	var gulp = require('gulp'),
	spawn = require('child_process').spawn,
	node;

	/**
	* $ gulp server
	* description: launch the server. If there's a server already running, kill it.