https://github.com/BaseSecrete/active_hashcash
Protect Rails applications against bots and brute force attacks without annoying humans.
https://github.com/BaseSecrete/active_hashcash
Last synced: 9 months ago
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Protect Rails applications against bots and brute force attacks without annoying humans.
- Host: GitHub
- URL: https://github.com/BaseSecrete/active_hashcash
- Owner: BaseSecrete
- License: mit
- Created: 2022-06-23T08:25:39.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2024-04-15T06:46:05.000Z (about 2 years ago)
- Last Synced: 2024-05-10T22:03:08.512Z (almost 2 years ago)
- Language: Ruby
- Homepage:
- Size: 855 KB
- Stars: 166
- Watchers: 7
- Forks: 5
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
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README
# ActiveHashcash
Protect Rails applications against bots and brute force attacks without annoying humans.
Hashcash is proof-of-work algorithm, invented by Adam Back in 1997, to protect systems against denial of service attacks.
ActiveHashcash is an easy way to protect any Rails application against brute force attacks and bots.
The idea is to force clients to spend some time to solve a hard problem that is very easy to verify for the server.
We have developed ActiveHashcash after seeing brute force attacks against our Rails application monitoring service [RorVsWild](https://rorvswild.com).
ActiveHashcash is ideal to set up on sensitive forms such as login and registration.
While the user is filling the form, the problem is solved in JavaScript and set the result into a hidden input text.
The form cannot be submitted while the proof of work has not been found.
Then the user submits the form, and the stamp is verified by the controller in a before action.
It blocks bots that do not interpret JavaScript since the proof of work is not computed.
More sophisticated bots and brute force attacks are slow down.
Moreover the complexity increases automatically for IP addresses sending many requests.
Thus it becomes very CPU costly for attackers.
Finally legitimate users are not annoyed by asking to solve a puzzle or clicking on the all images containing a bus.
Here is a [demo on a registration form](https://www.rorvswild.com/session) :
---
---
## Installation
Add this line to your application's Gemfile and run `bundle install`:
```ruby
gem "active_hashcash"
```
Stamps are stored into the database to prevents from spending them more than once.
You must install and run a migration:
```
rails active_hashcash:install:migrations
rails db:migrate
```
Then you have to include ActiveHashcash and add a `before_action :check_hashcash` in you controller:
```ruby
class SessionController < ApplicationController
include ActiveHashcash
# Only the action receiving the form needs to be protected
before_action :check_hashcash, only: :create
end
```
The action `SessionController#create` is now protected.
The final step is compute the hashcash from the client side.
Start by adding a Hashcash hidden field into the form you want to protect.
```erb
<%= hashcash_hidden_field_tag %>
```
Require hashcash from your JavaScript manifest.
```js
//= require hashcash
```
Or, link hashcash to your JavaScript manifest and load it to your head.
```js
//= link hashcash.js
```
```erb
<%= javascript_include_tag "hashcash", "data-turbo-track": "reload", defer: true %>
```
The hashcash stamp will be set in the hidden input once computed and the submit button enabled.
To customize behaviours, you can override methods of ActiveHashcash module.
### Dashboard
There is a mountable dashboard which allows to see all spent stamps.
It's not mandatory, but useful for monitoring purpose.
```ruby
# config/routes.rb
mount ActiveHashcash::Engine, at: "hashcash"
```
ActiveHashcash cannot guess how user authentication is handled, because it is different for all Rails applications.
So here is 3 options.
#### Inheritance
By default ActiveHashcash extends `ActionController::Base`, but you can change it to any controller, such as `AdminController`.
```ruby
# config/initializers/active_hashcash.rb
Rails.application.configure do
ActiveHashcash.base_controller_class = "AdminController"
end
```
#### Monkey patching
Monkey patching `ActiveHashcash::ApplicationController` let you inject your own mechanism.
```ruby
# lib/patches/active_hashcash.rb
ActiveHashcash::ApplicationController.class_eval do
before_action :require_admin
def require_admin
# This example supposes there are current_user and User#admin? methods
raise ActionController::RoutingError.new("Not found") unless current_user.try(:admin?)
end
end
end
```
Then the patch has to be loaded from after initialization:
```ruby
# config/application.rb
config.after_initialize do
require "patches/active_hashcash"
end
```
#### With Devise
Permission check can be achieved directly from routes.rb:
```ruby
# config/routes.rb
authenticate :user, -> (u) { u.admin? } do # Supposing there is a User#admin? method
mount ActiveHashcash::Engine, at: "hashcash" # http://localhost:3000/hashcash
end
```
### Before version 0.3.0
You must have Redis in order to prevent double spent stamps. Otherwise it will be useless.
It automatically tries to connect with the environment variables `ACTIVE_HASHCASH_REDIS_URL` or `REDIS_URL`.
You can also manually set the URL with `ActiveHashcash.redis_url = redis://user:password@localhost:6379`.
You should call `ActiveHashcash::Store#clean` once a day, to remove expired stamps.
To upgrade from 0.2.0 you must run the migration :
```
rails active_hashcash:install:migrations
rails db:migrate
```
## Complexity
Complexity is the most important parameter. By default its value is 20 and requires most of the time 5 to 20 seconds to be solved on a decent laptop.
The user won't wait that long, since he needs to fill the form while the problem is solving.
However, if your application includes people with slow and old devices, then consider lowering this value, to 16 or 18.
You can change the minimum complexity with `ActiveHashcash.bits = 20`.
Since version 0.3.0, the complexity increases with the number of stamps spent during le last 24H from the same IP address.
Thus it becomes very efficient to slow down brute force attacks.
## Limitations
The JavaScript implementation is 10 to 20 times slower than the official C version.
I first used the SubtleCrypto API but it is surprisingly slower than a custom SHA1 implementation.
Maybe I did in an inefficient way 2df3ba5?
Another idea would be to compile the work algorithm in wasm.
Unfortunately, I'm not a JavaScript expert.
Maybe you have good JS skills to optimize it?
Any help would be appreciate to better fights bots and brute for attacks!
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/BaseSecrete/active_hashcash.
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
Made by [Alexis Bernard](https://alexis.bernard.io/).
Made by