hapi-attempts-limiter

An hapi.js plugin that limits the number of failed attempts, based on IP and called route, using Redis to store attempts count. Useful for preventing brute force attacks.

Installation

npm install --save hapi-attempts-limiter

Usage

You need to register the plugin in you hapi server instance, providing some configuration attributes:

• redisClient: an instance of Redis
• namespace: a prefix for the items saved to Redis by the plugin (optional)
• errorMessage: a function that can be used to generate a custom error message (optional). Read the dedicated chapter for details.
• global.limit: the number of maximum failed attempts in the current time window (default: 5)
• global.duration: the length of the time window in seconds (default: 60 seconds)
• global.genericRateLimiter: a flag to transform the plugin in a generic rate limiter (default: false)
• global.trustProxy: a flag to use the latest IP address of x-forwarded-for header (AWS ELB format), if present (default: false)

server.register({
  register: require('hapi-attempts-limiter'),
  options: {
    namespace: 'FOO',
    redisClient: yourRedisInstance
    global: {
      limit: 5,
      duration: 60
    }
  }
});

Starting from the first failed attempt, the plugin will exposed three headers:

• X-RateLimit-Limit: the number of maximum failed attempts in the current time window
• X-RateLimit-Remaining: the number of remaining failed attempts in the current time window
• X-RateLimit-Reset: the seconds until the expiration of the current time window

CORS

If you are working with cross-domain requests using CORS protocol and you want to access X-RateLimit-* headers from your client, you have to expose them by adjusting the route configuration (or the global one):

cors: {
    origin: ['*'],
    additionalExposedHeaders: ['X-RateLimit-Limit', 'X-RateLimit-Remaining', 'X-RateLimit-Reset']
}

Route custom settings

Additionally, you can define for every route a custom limit and a custom duration. You just need to add some parameters to your route configuration object:

{
  method: 'POST',
  path: '/login',
  handler: loginUser,
  config: {
    description: 'User login route',
    plugins: {
      'hapi-attempts-limiter': {
          limit: 3, // a custom limit
          duration: 120 // a custom duration, in seconds
      }
    }
  }
}
//
{
  method: 'POST',
  path: '/heavy',
  handler: heavyRouteHandler,
  config: {
    description: 'Route to be called in moderation',
    plugins: {
      'hapi-attempts-limiter': {
          genericRateLimiter: true
      }
    }
  }
}

Custom error message

You can specify a custom error message by defining the function errorMessage in the plugin settings.

server.register({
  register: require('hapi-attempts-limiter'),
  options: {
    namespace: 'FOO',
    redisClient: yourRedisInstance,
    errorMessage: function (limit) {
      /*
       * Limit is an object that contains the following properties:
       * limit.remaining: the number of remaining attempts (0, in case of error)
       * limit.total: the number of available attempts
       * limit.duration: the length of the time window
       * limit.reset: the remaining time to the time window expiration
       *
       * You can return a Boom instance, an Error instance or a string that will be converted to a Boom 429 error.
      */
      return Boom.tooManyRequests('Rate limit exceeded, retry in ' + limit.reset + ' seconds');
    }
    global: {
      limit: 5,
      duration: 60
    }
  }
});

Happy coding!