_verifyAuthToken.js

  // Check whether user is Authenticated
  var _verifyAuthToken = function (authToken) {
    var deferred = require('q').defer()
      , usersService = require(__dirname + '/../services/users.js');

    // Check we have an authToken object
    if (authToken) {
      // Check for relevent properties
      if ( authToken.username && authToken.key ) {
        // Check key against HMAC
        if (_generateHMAC(authToken.username) === authToken.key) {
          // Ok, we got a valid token, let's grab the user
          usersService.find({username: authToken.username})
            .then(function (user) {
              if (user) {
                // We have a user, let's resolve
                deferred.resolve(user);
              } else {
                // No user? Reject.
                deferred.reject();
              }
            }, function () {
              // Something went wrong, reject
              deferred.reject();
            });
        } else {
          // Something went wrong, reject
          deferred.reject();
        }
      } else {
        // Something went wrong, reject
        deferred.reject();
      }
    } else {
      // Something went wrong, reject
      deferred.reject();
    }

    // Return the promsie
    return deferred.promise;
  };