SPAroid

Single Packet Authorization client implementation in Ruby, both a library and a CLI app. SPA sends a single encrypted and HMACed UDP package to a server, the server upon receiving it verifies and decrypts it and then executes a command, most often opening the firewall for the client that sent the package. This allows you to employ a reject-all firewall but open the firewall for e.g. SSH access. It's a first line of defence, in the case of 0-day attacks on SSH or similar.

Add this line to your application's Gemfile:

gem 'sparoid'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install sparoid

...

Can be used with OpenSSH's ProxyCommand/ProxyUseFdpass to send the packet before connecting, open the TCP connection and that pass that connection back to the SSH client.

Host *.example.com
  ProxyCommand sparoid connect %h %p
  ProxyUseFdpass yes

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/84codes/sparoid.rb.

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