Pwned

An easy, Ruby way to use the Pwned Passwords API.

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Table of Contents

About

Troy Hunt’s Pwned Passwords API V2 allows you to check if a password has been found in any of the huge data breaches.

Pwned is a Ruby library to use the Pwned Passwords API’s k-Anonymity model to test a password against the API without sending the entire password to the service.

The data from this API is provided by Have I been pwned?. Before using the API, please check the acceptable uses and license of the API.

Here is a blog post I wrote on how to use this gem in your Ruby applications to make your users’ passwords better.

Installation

Add this line to your application’s Gemfile:

ruby gem 'pwned'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pwned

Usage

There are a few ways you can use this gem:

  1. Plain Ruby
  2. Rails
  3. Rails and Devise

Plain Ruby

To test a password against the API, instantiate a Pwned::Password object and then ask if it is pwned?.

ruby password = Pwned::Password.new("password") password.pwned? #=> true password.pwned_count #=> 3303003

You can also check how many times the password appears in the dataset.

ruby password = Pwned::Password.new("password") password.pwned_count #=> 3303003

Since you are likely using this as part of a signup flow, it is recommended that you rescue errors so if the service does go down, your user journey is not disturbed.

ruby begin password = Pwned::Password.new("password") password.pwned? rescue Pwned::Error => e # Ummm... don't worry about it, I guess? end

Most of the times you only care if the password has been pwned before or not. You can use simplified accessors to check whether the password has been pwned, or how many times it was pwned:

ruby Pwned.pwned?("password") #=> true Pwned.pwned_count("password") #=> 3303003

Advanced

You can set http request options to be used with Net::HTTP.start when making the request to the API. These options are documented in the Net::HTTP.start documentation. The :headers option defines defines HTTP headers. These headers must be string keys.

ruby password = Pwned::Password.new("password", headers: { 'User-Agent' => 'Super fun new user agent' }, read_timeout: 10)

ActiveRecord Validator

There is a custom validator available for your ActiveRecord models:

ruby class User < ApplicationRecord validates :password, not_pwned: true # or validates :password, not_pwned: { message: "has been pwned %{count} times" } end

I18n

You can change the error message using I18n (use %{count} to interpolate the number of times the password was seen in the data breaches):

yaml en: errors: messages: not_pwned: has been pwned %{count} times pwned_error: might be pwned

Threshold

If you are ok with the password appearing a certain number of times before you decide it is invalid, you can set a threshold. The validator will check whether the pwned_count is greater than the threshold.

ruby class User < ApplicationRecord # The record is marked as valid if the password has been used once in the breached data validates :password, not_pwned: { threshold: 1 } end

Network Error Handling

By default the record will be treated as valid when we cannot reach the haveibeenpwned.com servers. This can be changed with the :on_error validator parameter:

```ruby class User < ApplicationRecord # The record is marked as valid on network errors. validates :password, not_pwned: true validates :password, not_pwned: { on_error: :valid }

# The record is marked as invalid on network errors # (error message “could not be verified against the past data breaches”.) validates :password, not_pwned: { on_error: :invalid }

# The record is marked as invalid on network errors with custom error. validates :password, not_pwned: { on_error: :invalid, error_message: “might be pwned” }

# We will raise an error on network errors. # This means that record.valid? will raise Pwned::Error. # Not recommended to use in production. validates :password, not_pwned: { on_error: :raise_error }

# Call custom proc on error. For example, capture errors in Sentry, # but do not mark the record as invalid. validates :password, not_pwned: { on_error: ->(record, error) { Raven.capture_exception(error) } } end ```

Custom Request Options

You can configure network requests made from the validator using :request_options (see Net::HTTP.start for the list of available options). In addition to these options, HTTP headers can be specified with the :headers key, e.g. "User-Agent"):

ruby validates :password, not_pwned: { request_options: { read_timeout: 5, open_timeout: 1, headers: { "User-Agent" => "Super fun user agent" } } }

Devise

If you are using Devise I recommend you use the devise-pwned_password extension which is now powered by this gem.

How Pwned is Pi?

@daz shared a fantastic example of using this gem to show how many times the digits of Pi have been used as passwords and leaked.

```ruby require ‘pwned’

PI = ‘3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111’

for n in 1..40 password = Pwned::Password.new PI[0..(n + 1)] str = [ n.to_s.rjust(2) ] str « (password.pwned? ? ‘😡’ : ‘😃’) str « password.pwned_count.to_s.rjust(4) str « password.password

puts str.join ‘ ‘ end ```

The results may, or may not, surprise you.

1 😡 16 3.1 2 😡 238 3.14 3 😡 34 3.141 4 😡 1345 3.1415 5 😡 2552 3.14159 6 😡 791 3.141592 7 😡 9582 3.1415926 8 😡 1591 3.14159265 9 😡 637 3.141592653 10 😡 873 3.1415926535 11 😡 137 3.14159265358 12 😡 103 3.141592653589 13 😡 65 3.1415926535897 14 😡 201 3.14159265358979 15 😡 41 3.141592653589793 16 😡 57 3.1415926535897932 17 😡 28 3.14159265358979323 18 😡 29 3.141592653589793238 19 😡 1 3.1415926535897932384 20 😡 7 3.14159265358979323846 21 😡 5 3.141592653589793238462 22 😡 2 3.1415926535897932384626 23 😡 2 3.14159265358979323846264 24 😃 0 3.141592653589793238462643 25 😡 3 3.1415926535897932384626433 26 😃 0 3.14159265358979323846264338 27 😃 0 3.141592653589793238462643383 28 😃 0 3.1415926535897932384626433832 29 😃 0 3.14159265358979323846264338327 30 😃 0 3.141592653589793238462643383279 31 😃 0 3.1415926535897932384626433832795 32 😃 0 3.14159265358979323846264338327950 33 😃 0 3.141592653589793238462643383279502 34 😃 0 3.1415926535897932384626433832795028 35 😃 0 3.14159265358979323846264338327950288 36 😃 0 3.141592653589793238462643383279502884 37 😃 0 3.1415926535897932384626433832795028841 38 😃 0 3.14159265358979323846264338327950288419 39 😃 0 3.141592653589793238462643383279502884197 40 😃 0 3.1415926535897932384626433832795028841971

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/philnash/pwned. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Pwned project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.