# 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: ```ruby gem 'ip_anonymizer' ``` There are two strategies for anonymizing IPs. ### Masking This is the approach [Google Analytics uses for IP anonymization](https://support.google.com/analytics/answer/2763052): - For IPv4, the last octet is set to 0 - For IPv6, the last 80 bits are set to zeros ```ruby 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). ```ruby 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`: ```ruby config.middleware.insert_after ActionDispatch::RemoteIp, IpAnonymizer::MaskIp ``` For hashing, use: ```ruby config.middleware.insert_after ActionDispatch::RemoteIp, IpAnonymizer::HashIp, key: "secret" ``` ## History View the [changelog](https://github.com/ankane/ip_anonymizer/blob/master/CHANGELOG.md) ## Contributing Everyone is encouraged to help improve this project. Here are a few ways you can help: - [Report bugs](https://github.com/ankane/ip_anonymizer/issues) - Fix bugs and [submit pull requests](https://github.com/ankane/ip_anonymizer/pulls) - Write, clarify, or fix documentation - Suggest or add new features To get started with development and testing: ```sh git clone https://github.com/ankane/ip_anonymizer.git cd ip_anonymizer bundle install rake test ```