Generate code that checks a password

createChallenge.js

function createChallenge (input, goal, hash) {
  input = input.replace(/ /g, '');
  var challengeLength = 16;
  var challenge = hash(hash(input) + 'god damned internet').substr(0, challengeLength);
  goal += challenge;
  // after using input...
  // right away just hash it, we never really want to work with the raw value
  input = hash(input);
  var outputLength = 0;
  var fnOutput = "";
  var currentIndentation = 0;

  log('function checkPassphrase (input, hash) {');
  currentIndentation++;
  log('input = input.replace(/ /g, "");');
  log('var challenge = hash(hash(input) + "god damned internet").substr(0, ' + challengeLength + ');');
  log('input = hash(input);');
  log('var output = "";');

  while (outputLength < goal.length) {
    var index = input.indexOf(goal[outputLength]);

    if (index !== -1) {
      log('output += input[' + index + '];');
      outputLength++;
    }
    var salt = (Math.random() + '').substr(0, challengeLength);
    input = hash(input + salt);
    log('input = hash(input + "' + salt + '");');
  }

  log('if (output.substr(-' + challengeLength + ') === challenge) {');
  currentIndentation++;
  log('return output.substr(0, output.length - ' + challengeLength + ');');
  currentIndentation--;
  log('}');
  log('return false;');
  currentIndentation--;
  log('}');

  return fnOutput;

  function log (msg) {
    for (var i = 0; i < currentIndentation; ++i) {
      msg = '  ' + msg;
    }
    console.log(msg);
    fnOutput += msg + '\n';
  }
}