chrisveness’s gists

chrisveness / sha3-32bit.js

Created April 3, 2017 10:30

32-bit version of SHA-3 (Keccak) algorithm using bit-interleaving

	/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
	/* SHA-3 (FIPS 202) ‘Keccak’ reference implementation in JavaScript (c) Chris Veness 2016-2017 */
	/* MIT Licence */
	/* www.movable-type.co.uk/scripts/sha3.html */
	/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

	'use strict';


	/**

chrisveness / crypto-aes-gcm.js

Last active October 5, 2024 16:59

Uses the SubtleCrypto interface of the Web Cryptography API to encrypt and decrypt text using AES-GCM (AES Galois counter mode).

	/**
	* Encrypts plaintext using AES-GCM with supplied password, for decryption with aesGcmDecrypt().
	* (c) Chris Veness MIT Licence
	*
	* @param {String} plaintext - Plaintext to be encrypted.
	* @param {String} password - Password to use to encrypt plaintext.
	* @returns {String} Encrypted ciphertext.
	*
	* @example
	* const ciphertext = await aesGcmEncrypt('my secret text', 'pw');

chrisveness / crypto-pbkdf2.js

Last active October 25, 2024 21:03

Uses the SubtleCrypto interface of the Web Cryptography API to hash a password using PBKDF2, and validate a stored password hash against a subsequently supplied password. Note that both bcrypt and scrypt offer better defence against ASIC/GPU attacks, but are not available within WebCrypto.

	/**
	* Returns PBKDF2 derived key from supplied password.
	*
	* Stored key can subsequently be used to verify that a password matches the original password used
	* to derive the key, using pbkdf2Verify().
	*
	* @param {String} password - Password to be hashed using key derivation function.
	* @param {Number} [iterations=1e6] - Number of iterations of HMAC function to apply.
	* @returns {String} Derived key as base64 string.
	*

chrisveness / crypto-sha.js

Last active July 20, 2023 04:45

Uses the SubtleCrypto interface of the Web Cryptography API to hash a message using SHA-256.

	/**
	* Returns SHA-256 hash from supplied message.
	*
	* @param {String} message.
	* @returns {String} hash as hex string.
	*
	* @example
	* sha256('abc').then(hash => console.log(hash));
	* const hash = await sha256('abc');
	*/

chrisveness / standard-deviation.js

Created September 21, 2016 22:13

Standard deviation of set of values

	/**
	* Returns standard deviation of set of values.
	*
	* @param {number[]} values - Array of values.
	* @returns {number} Standard devation of values.
	*/
	function stdDeviation(values) {
	const avgOfValues = average(values);
	const squaresOfDiffs = values.map(value => (value-avgOfValues)**2);
	const avgOfSquaresOfDiffs = average(squaresOfDiffs);

chrisveness / mongodb-objectid.js

Created September 14, 2016 11:32

Generates a MongoDB-style ObjectId in Node.js

	/**
	* Generates a MongoDB-style ObjectId in Node.js. Uses nanosecond timestamp in place of counter;
	* should be impossible for same process to generate multiple objectId in same nanosecond? (clock
	* drift can result in an extremely remote possibility of id conflicts).
	*
	* @returns {string} Id in same format as MongoDB ObjectId.
	*/
	function objectId() {
	const os = require('os');
	const crypto = require('crypto');

chrisveness / index.html

Last active January 3, 2023 06:50

JavaScript AES client/server interoperability test

	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<title>AES client/server test</title>
	<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/normalize/3.0.3/normalize.min.css">
	<style>
	body { font-size: 80%; padding: 1em; }
	form { margin-top: 2em; }
	label { display: inline-block; width: 6em; }

chrisveness / app.js

Created February 20, 2015 00:49

supertest fails when using cookie domain / header host

	var koa = require('koa');
	var session = require('koa-session');

	var app = module.exports = koa();

	app.keys = ['some secret hurr'];
	app.use(session({ domain: '.app.localhost' }, app)); // THIS WORKS IN BROWSER BUT FAILS IN SUPERTEST
	//app.use(session(app)); // THIS WORKS EITHER WAY

	app.use(function*() {

chrisveness / app.js

Last active August 29, 2015 14:15

koa-flash fails when session domain opts set

	var koa = require('koa');
	var session = require('koa-session');
	var flash = require('koa-flash');
	var router = require('koa-router');
	var handlebars = require("koa-handlebars");

	var app = koa();

	app.keys = ['foo'];
	app.use(session({ domain: '.localhost' }, app)); // THIS FAILS

chrisveness / hyphen-camel.js

Last active August 29, 2015 14:07

Convert between camel-cased & hyphenated strings (eg SomeResourceName <=> some-resource-name)

	/**
	* Returns camel-cased equivalent of (lower-case) hyphenated string.
	*
	* To enable round-tripping, hyphens not followed by a-z are left intact
	* (can be checked for and/or removed manually if required).
	*
	* Only transforms ASCII capitals (lack of JavaScript Unicode regexp).
	*/
	function hyphenToCamel(str) {
	// for Unicode transforms, replace [a-z] with \p{Ll} if available

Chris Veness chrisveness