WIP: DC26 Badge Challenge

dc26-badge-cryptanalysis.js

const { Buffer } = require('buffer');

const arcadePoster     = Buffer.from('2BFC8E2B3561C04FBBC73FA43D5D96540D0AA008B30924CE47DA0EC67530D3', 'hex');
const arcadeGraffiti   = Buffer.from('9E1CE2C2F6FBFE198637E6F10B957DDD50A7874177A51E', 'hex');
const humanoidNote     = Buffer.from('FEEDB0B0DEADBEEF', 'hex');
const noteThenGraffiti = Buffer.from('FEEDB0B0DEADBEEF9E1CE2C2F6FBFE198637E6F10B957DDD50A7874177A51E', 'hex');
const graffitiThenNote = Buffer.from('9E1CE2C2F6FBFE198637E6F10B957DDD50A7874177A51EFEEDB0B0DEADBEEF', 'hex');

const merge = (A, B, f) => Buffer.from(Array.from(A).map((n, index) => f(n, B[index % B.length])));

const formats = ['utf8', 'base64', 'ascii', 'hex'];

const pairs = [
  [arcadePoster, noteThenGraffiti],
  [arcadePoster, graffitiThenNote],
  [noteThenGraffiti, arcadePoster],
  [graffitiThenNote, arcadePoster],
  [noteThenGraffiti, graffitiThenNote],
  [graffitiThenNote, noteThenGraffiti]
];

const operations = [
  (a, b) => a ^ b,
  (a, b) => a | b,
  (a, b) => a & b,
  (a, b) => (a + b) & 0x100,
  (a, b) => (a - b) & 0x100,
  (a, b) => a % b,
  (a, b) => (a << b) & 0x100,
  (a, b) => (a >> b) & 0x100
];

console.log(JSON.stringify(pairs.map((pair) => formats.map((format) => operations.map((operation) => merge(pair[0], pair[1], operation).toString(format)))), null, 2));