chrisdl

(see the picture in the first comment)

chrisdl

Legacy Code

Definition

• Classical: Code that relates to something which is no longer supported.
• Modern: (1) source code inherited from someone else and (2) source code inherited from an older version of the software.

(3) BOTH Trifecta

How does it happen? (types)

• Inherited from someone else: Employee who built can't work on it anymore.

chrisdl

const crypto = require("crypto");

class Db {
  constructor(users={}) {
    this.users = users;
  }

  // Expects passwordPayload to be a string of the form 'salt$passwordHash'
  // Where the '$' is used as a separator.
  storeUser(username, passwordPayload) {

chrisdl

// https://nodejs.org/api/crypto.html#crypto_class_cipher
// 'aes256' -> AES256 - CBC
// The available ciphers depend on openssl. See ``$> openssl list-cipher-algorithms`` for a list.
const crypto = require("crypto");

const encrypt = (key, plaintext) => {
  const cipher = crypto.createCipher("aes256", key);
  let ciphertext = cipher.update(plaintext, "utf8", "hex");
  ciphertext += cipher.final("hex");
  return ciphertext;

chrisdl

const crypto = require("crypto");

class Db {
  constructor(users={}) {
    this.users = users;
  }

  // Expects passwordPayload to be a string of the form 'salt$passwordHash'
  // Where the '$' is used as a separator.
  storeUser(username, passwordPayload) {

chrisdl

const crypto = require("crypto");

const hashFunction = crypto.createHash("sha256");
const plaintext = "123456";
hashFunction.update(plaintext);
const hash = hashFunction.digest("hex");

console.log(hash);

// Things to try:

chrisdl

• plaintext = The secret text (message, password, ...) you want to encrypt.
• ciphertext = A plaintext that has been encrypted.
• cipher = A mathematical function that takes at least a key and a plaintext and produces a ciphertext. For example: AES.
• hash function = A mathematical function that produces a hash which cannot be reversed back to plaintext.
• key = A secret key that allows someone to decrypt a ciphertext back into a plaintext.
• secret = see key.

chrisdl

Keybase proof

I hereby claim:

• I am chrisdl on github.
• I am chrisdl (https://keybase.io/chrisdl) on keybase.
• I have a public key ASDQYgsg3r5Pqx0G9Ut_xjCYzQUJr-fcFb1oGbzLDRmvSAo

To claim this, I am signing this object:

chrisdl

(py27) ubuntu@ubuntu-xenial:/vagrant$ bpython
bpython version 0.16 on top of Python 2.7.12 /home/ubuntu/.virtualenvs/py27/bin/python
>>> from Crypto.Hash import HMAC
>>> import os
>>> import binascii
>>> key = binascii.hexlify(os.urandom(32))
>>> msg = 'Hello World'
>>> my_hmac = HMAC.new(key=key, msg=msg)
>>> import Crypto
>>> Crypto.version_info

chrisdl

// This kind of sucks because is relies on the window object which means the React will have issues being Isomorphic (rendered server side).
// So if anyone has a better suggestion as to attaching to a global object and waiting for it to exist i'm all ears.


// main.js
requirejs.config({
    paths: {
        EventEmitter: "vendor/EventEmitter"
    },
    shim: {