UrlSigner

Quickly generate and verify signed urls.

Installation

Add this line to your application's Gemfile:

gem 'url_signer'

And then execute:

$ bundle

Or install it yourself as:

$ gem install url_signer

Usage

URL signing

To convert a URL into a signed url, pass it to UrlSigner.sign, passing it either a string of an instance of URI.

# generate a new URI instance with `signature` param populated
signed_url = UrlSigner.sign('http://google.fr?q=test', key: 'mykey')

the returned value signed_url is an instance of URI.

URL verification

Given a signed URL, you can check its authenticity by calling UrlSigner.valid? on it:

# verify url validity for a given URI instance
UrlSigner.valid?(signed_url, key: 'mykey') # => true

helper methods on URI

The gem adds helper methods to String and URI classes:

# to generate a signed uri directly form a string
signed_url = 'http://google.fr'.to_signed_uri(key: 'test')

# or if we have a URI insance already
url = URI.parse('http://google.fr')
signed_url = url.signed(key: 'test')

Rails integration

When using Rails, a set of helpers are added to ActionController::Base:

class MyController < ActionController::Base
  def get_signed_url
    @signed_url = sign_url(signed_url_my_controller_url)
    # Template will link to @signed_url
  end

  before_action :verify_signature!
  def signed_url
    # This method is only accessible with a signed url
  end
end

The key and hash method used in sign_url and verify_signature! are provided through Rails.configuration.url_signer, which default to:

# defaults values:
Rails.configuration.url_signer.key = ENV['URL_SIGNING_KEY']
Rails.configuration.url_signer.hash_method = Digest::SHA1

Note that provided env URL_SIGNING_KEY environment variable is usually enough to get a working URL signing environment.

Contributing

1. Fork it ( https://github.com/[my-github-username]/url_sign/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request