altcha/scripts/obfuscate.ts

/**
 * Run this script with Bun:
 * 
 * bun run scripts/obfuscate.ts "mailto:..."
 * 
 * or with Node:
 *
 * npx tsx scripts/obfuscate.ts "mailto:..."
 */

const MAX_NUMBER = parseInt(process.env.MAX_NUMBER || '10000', 10);
const NUMBER = process.env.NUMBER ? parseInt(process.env.NUMBER || '0', 10) : undefined;
const KEY = process.env.KEY || '';

function randomInt(max: number) {
  const ab = new Uint32Array(1);
  crypto.getRandomValues(ab);
  const randomNumber = ab[0] / (0xffffffff + 1);
  return Math.floor(randomNumber * max + 1);
}

async function uInt8ArrayToBase64(ua: Uint8Array) {
  return Buffer.from(ua).toString('base64');
}

function numberToUint8Array(num: number, len: number = 12) {
  const ua = new Uint8Array(len);
  for (let i = 0; i < len; i++) {
    ua[i] = num % 256;
    num = Math.floor(num / 256);
  }
  return ua;
}

async function obfuscateData(
  raw: string,
  key: string = '',
  number: number = NUMBER || randomInt(MAX_NUMBER),
) {
  const encoder = new TextEncoder();
  const encodedData = encoder.encode(raw);
  const algorithm = { name: 'AES-GCM', iv: numberToUint8Array(number) };
  const keyHash = await crypto.subtle.digest(
    'SHA-256',
    encoder.encode(key)
  );
  const keyData = await crypto.subtle.importKey(
    'raw',
    keyHash,
    algorithm,
    false,
    ['encrypt']
  );
  const encryptedData = await crypto.subtle.encrypt(
    algorithm,
    keyData,
    encodedData
  );
  return uInt8ArrayToBase64(new Uint8Array(encryptedData));
}

console.log(await obfuscateData(process.argv[process.argv.length - 1], KEY));

export {};