Code0::License

Code0::License can create and validate software licenses.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add code0-license

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install code0-license

Usage

To start using the gem, you need to have a public and private RSA key. If you don't have a key pair, you can generate one by running bin/create_key

To generate a license, use the private key as encryption key:

require "code0/license"

# read private key from file
private_key_file = File.read('license_key.key')
private_key = OpenSSL::PKey::RSA.new(private_key_file)

# set private key as encryption key
Code0::License.encryption_key = private_key

# create a license
license = Code0::License.new(
  {
    licensee: { company: 'Code0' }, # content of licensee can be as you want, it just can't be empty
    start_date: '2024-05-01', # when is the first date where this license is valid?
    end_date: '2025-05-01', # until when is the license valid?
    restrictions: {}, # content can be as you wish, can be used to semantically store some restrictions that are evaluated by your application
    options: {}, # content can be as you wish, can be used to semantically provide some options of this license
  }
)

# export the license
File.write('license.txt', Code0::License.export(license, 'CODE0'))

To verify the license in your application, use the public key

require "code0/license"

# read public key from file
public_key_file = File.read('license_key.pub')
public_key = OpenSSL::PKey::RSA.new(public_key_file)

# set public key as encryption key
Code0::License.encryption_key = public_key

# load the license
license = Code0::License.load(File.read('license.txt'))

# exit if license is not valid or outside of the valid time
exit unless license.valid?
exit unless license.in_active_time?

# for example, exit if users exceed licensed amount
exit if license.restricted?(:user_count) && User.count > license.restrictions[:user_count]