distributed-jwt-cracker/src/server/createRouter.js

An experimental distributed JWT token cracker built using Node.js and ZeroMQ

'use strict';

const bigInt = require('big-integer');

const createRouter = (batchSocket, signalSocket, token, alphabet, batchSize, start, logger, exit) => {
  let cursor = bigInt(String(start));
  const clients = new Map();

  const assignNextBatch = client => {
    const from = cursor;
    const to = cursor.add(batchSize).minus(bigInt.one);
    const batch = [from.toString(), to.toString()];
    cursor = cursor.add(batchSize);
    client.currentBatch = batch;
    client.currentBatchStartedAt = new Date();

    return batch;
  };

  const addClient = channel => {
    const id = channel.toString('hex');
    const client = {id, channel, joinedAt: new Date()};
    assignNextBatch(client);
    clients.set(id, client);

    return client;
  };

  const router = (channel, rawMessage) => {
    const msg = JSON.parse(rawMessage.toString());

    switch (msg.type) {
      case 'join': {
        const client = addClient(channel);
        const response = {
          type: 'start',
          id: client.id,
          batch: client.currentBatch,
          alphabet,
          token
        };
        batchSocket.send([channel, JSON.stringify(response)]);
        logger.info(`${client.id} joined (batch: ${client.currentBatch[0]}-${client.currentBatch[1]})`);
        break;
      }

      case 'next': {
        const batch = assignNextBatch(clients.get(channel.toString('hex')));
        logger.info(`client ${channel.toString('hex')} requested new batch, sending ${batch[0]}-${batch[1]}`);
        batchSocket.send([channel, JSON.stringify({type: 'batch', batch})]);
        break;
      }

      case 'success': {
        const pwd = msg.password;
        logger.info(`client ${channel.toString('hex')} found password "${pwd}"`);
        // publish exit signal and closes the app
        signalSocket.send(['exit', JSON.stringify({password: pwd, client: channel.toString('hex')})], 0, () => {
          batchSocket.close();
          signalSocket.close();
          exit(0);
        });

        break;
      }

      default:
        logger.error('invalid message received from channel', channel.toString('hex'), rawMessage.toString());
    }
  };

  router.getClients = () => clients;

  return router;
};

module.exports = createRouter;