IP Anonymizer

:earth_americas: IP address anonymizer for Ruby

Works with IPv4 and IPv6, and includes middleware for Rails

Getting Started

Add these lines to your application’s Gemfile:

gem 'ip_anonymizer'

There are two strategies for anonymizing IPs.

Masking

This is the approach Google Analytics uses for IP anonymization:

  • For IPv4, the last octet is set to 0
  • For IPv6, the last 80 bits are set to zeros
IpAnonymizer.mask_ip("8.8.4.4")
# => "8.8.4.0"

IpAnonymizer.mask_ip("2001:4860:4860:0:0:0:0:8844")
# => "2001:4860:4860::"

An advantange of this approach is geocoding will still work, only with slightly less accuracy.

Hashing

Transform IP addresses with a keyed hash function (PBKDF2-HMAC-SHA256).

IpAnonymizer.hash_ip("8.8.4.4", key: "secret")
# => "6.128.151.207"

IpAnonymizer.hash_ip("2001:4860:4860:0:0:0:0:8844", key: "secret")
# => "f6e4:a4fe:32dc:2f39:3e47:84cc:e85e:865c"

Be sure to keep the key secret, or else a rainbow table can be constructed.

Rails

Automatically anonymize request.remote_ip in Rails.

For masking, add to config/application.rb:

config.middleware.insert_after ActionDispatch::RemoteIp, IpAnonymizer::MaskIp

For hashing, use:

config.middleware.insert_after ActionDispatch::RemoteIp, IpAnonymizer::HashIp, key: "secret"

History

View the changelog

Contributing

Everyone is encouraged to help improve this project. Here are a few ways you can help:

To get started with development and testing:

git clone https://github.com/ankane/ip_anonymizer.git
cd ip_anonymizer
bundle install
rake test