My solution to the Stripe CTF3 level1 challenge. `node work.js`

node-miner.js

var crypto = require('crypto');
var fs = require('fs');
var exec = require('child_process').exec;
var async = require('async');

function solve() {
  async.auto({
    reset: function (callback) {
      exec('git fetch origin && git reset --hard origin/master && (grep -q "user-lceye6qv" LEDGER.txt || echo "user-lceye6qv: 1" >> LEDGER.txt) && git add LEDGER.txt', function (err, stdout) {
        callback(null, null);
      });
    },
    tree: ['reset', function (callback) {
      exec('git write-tree', function (err, stdout) {
        callback(null, stdout.trim());
      });
    }],
    parent: ['reset', function (callback) {
      exec('git rev-parse HEAD', function (err, stdout) {
        callback(null, stdout.trim());
      });
    }],
    timestamp: function (callback) {
      exec('date +%s', function (err, stdout) {
        callback(null, stdout.trim());
      });
    },
  }, function (err, result) {
    var counter = Math.floor((Math.random()*10000000)+1);
    while (++counter) {
      var shasum = crypto.createHash('sha1');
      var body = "tree " + result.tree + "\n" +
        "parent " + result.parent + "\n" +
        "author Ian Christian Myers <[email protected]> " + result.timestamp + " -0800\n" +
        "committer Ian Christian Myers <[email protected]> " + result.timestamp + " -0800\n\n" +
        "Give me a Gitcoin\n\n" + counter + "\n";

      var store = 'commit ' + body.length + "\0" + body;
      shasum.update(store);

      var digest = shasum.digest('hex');

      if (digest < "000001") {
        fs.writeFileSync('./commit', body);            
        process.send('Found Gitcoin: ' + digest);
        exec('git hash-object -t commit -w commit', function (err, stdout, stderr) {
          var hashObj = stdout.trim();
          exec('git reset --hard ' + hashObj + ' && git push origin master', function (err, stdout, stderr) {
            if (err) {
              process.send('Starting over.');
              solve();
            } else {
              process.send('Success.');
            }
          });
        });
        break;
      }
    }
  });
}

solve();

work.js

var cp = require('child_process');

var children = [];
var count = 100;

while (--count) {
  children[count] = cp.fork('./node-miner');

  children[count].on('message', function (data) {
    console.log(data);
  });

  children[count].on('close', function (code) {
    console.log('closed');
  });
}