Sikka - A Firewall for Meteor Apps

This is an application level firewall for Meteor. Sikka can detect malicious users of your app and block those users. We've build basic rate limiting support and it is well tested and works with most of the Meteor deployments techniques. We also have a huge roadmap and a feature set.

Installation

meteor add meteorhacks:sikka

Sikka comes with sufficient set of defaults, which is okay for a common Meteor app. But, it's better if you can tweak them for your needs. Refer following section for that.

All of the configurations are based on either environment variables or with Meteor.settings

Supported Features

Let's talk about supported features.

DDP Rate Limiting

You can configure a maximum number of DDP requests allowed per IP. If any of the IPs exceed that limit, we'll block that IP for couple of minutes.

We don't disconnect the DDP connection, but rather ignore the traffic. By doing that, attacker can't detect whether we've blocked his requests or our app goes down.

Here are some parameters you can configure.

Description	Environment Variable	Meteor.settings key	default
Per IP rate limit (per sec)	SIKKA_PER_IP_MAX_RPS	sikka.rateLimits.perIp	20
Time to block an IP	SIKKA_BLOCK_IP_FOR_MILLIS	sikka.times.blockIpFor	120000

Human Verification (Captcha Support)

Sometimes, it's possible for attacker to exist with legitimate users. So, when we block requests, legitimate users won't be able access our app. To solve this issue, we ask users to verify them as humans by completing a captcha.

Here are some parameters you can configure

Description	Environment Variable	Meteor.settings key	default
Captcha Site Key	SIKKA_CAPTCHA_SITE_KEY	sikka.captcha.siteKey
Captcha Secret	SIKKA_CAPTCHA_SECRET	sikka.captcha.secret
Per Human Rate Limit (per sec)	SIKKA_PER_HUMAN_MAX_RPS	sikka.rateLimits.perHuman	IP Rate Limit
Millis Human Lifetime (expired after that)	SIKKA_HUMAN_LIVES_UPTO_MILLIS	sikka.times.humanLivesUpto	3600000

Here is an example of a settings.json file:

{
    "sikka": {
         "captcha": {
             "siteKey": "your_new_site_key",
             "secret":  "your_new_secret_key"
         }
    }
}

You can apply the settings with:

meteor --settings path/to/settings.json

Visit Google's Recaptcha website to get Captcha keys for your domain. We've added a default set of keys works on locally, meteor.com and onmodulus.net to make your development experience simpler. But, you should get a new pair of keys for a production deployment.

Humans Only Mode

Let's say, your app is under an attack. So, you can make your app to reject all DDP requests and ask for human verification by default. This is how you can configure it.

To enable this mode. Just export following environment variable or Meteor settings key.

• Environment Variable: SIKKA_ONLY_FOR_HUMANS
• Meteor Settings key: sikka.onlyForHumans

Support Deployment Methods

If your app behind a proxy or a SSL terminator, it needs to add x-forwarded-for header with the actual IP address.

Tested Proxies / SSL Terminators

• proxy of meteor.com
• proxy of modulus.io
• Cloudflare
• Cloudflare with SSL
• Nginx with proxy_set_header

Failed Proxies / SSL Terminators

• Meteor Up's SSL terminator - we'll have a fix soon.