mario-royale/decode.js

const beautify = require('js-beautify').js_beautify
const fs = require('fs')
let code = fs.readFileSync('./game.min.js', 'utf8')

// Get dictionary name, stores base64 encoded strings.
let dictName = /^var (\S+)=\[/.exec(code)[1]

// Get the dictionary itself
let dict = JSON.parse(/(\[[^\]]*\])/.exec(code)[1].split("'").join('"')).map(x => Buffer.from(x, 'base64').toString()).map(x => JSON.stringify(x))

// Find the offset for the dictionary
let offset = parseInt(new RegExp(`\\(${dictName},0x([^\\)]*)\\)`).exec(code)[1], 16)

// Find the dictionary function name
let func = new RegExp(`\\(${dictName},0x${offset.toString(16)}\\)\\);var (_0x[^=]*)=`).exec(code)[1]

// Apply the offset
while (--offset >= 0) dict.push(dict.shift())

// Replace strings
code = code.replace(new RegExp(`${func}\\('0x([^']*)'\\)`, 'g'), (_, id) => dict[parseInt(id, 16)])

// Replace x["simpleName"] with x.simpleName
code = code.replace(/\["([a-zA-Z0-9_-]*)"\]/g, (_, x) => `.${x} `)

// Find reverse string function (keep in mine, properties have trailing spaces at this point)
reverseFunc = /(_0x[^\.]+\.\S+) =function\(_0x[^\)]+\){return _0x[^\)]+\.split \(''\)\.reverse \(\)\.join \(''\);}/.exec(code)[1]

// Replace blah.reverse ("gnirtSemos") with "someString"
code = code.replace(new RegExp(`${reverseFunc} \\(("[^"]*")\\)`, 'g'), (_, x) => JSON.stringify(JSON.parse(x).split('').reverse().join('')))

// Replace x["simpleName"] with x.simpleName
code = code.replace(/\["([a-zA-Z0-9_-]*)"\]/g, (_, x) => `.${x} `)

// Replace hex with int
code = code.replace(/([^_])0x([a-f0-9]+)([^"])/g, (_, a, b, c) => `${a}${parseInt(b, 16)}${c}`)


// label Menu class
code = code.split(/this.menu =new (_0x[0-9a-f]*)/.exec(code)[1]).join('Menu')

// label Net class
code = code.split(/this.net =new (_0x[0-9a-f]*)/.exec(code)[1]).join('Net')

// label Game class
code = code.split(/case "game":this.game =new (_0x[0-9a-f]*)/.exec(code)[1]).join('Game')

// label Lobby class
code = code.split(/case "lobby":this.game =new (_0x[0-9a-f]*)/.exec(code)[1]).join('Lobby')

// label Jail class
code = code.split(/case "jail":this.game =new (_0x[0-9a-f]*)/.exec(code)[1]).join('Jail')



// Beautify code
code = beautify(code, {
  indent_size: 2
})



fs.writeFileSync('game.decoded.js', code)