Frontegg JWT Token Validator

A Ruby library for validating Frontegg JWT tokens. This library fetches the JSON Web Key Set (JWKS) from Frontegg's well-known OIDC endpoint and uses it to validate JWT tokens.

Installation

Add this line to your application's Gemfile:

gem 'frontegg_jwt_validator'

And then execute:

bundle install

Or install it yourself as:

gem install frontegg_jwt_validator

Usage

Basic Usage

require 'frontegg_jwt_validator'

# Initialize the validator with your Frontegg domain
validator = FronteggJWTValidator.new('acme.frontegg.com')

# Fetch the JWKS
validator.fetch_jwks

# Validate a token
begin
  payload = validator.validate_token('your.jwt.token')
  puts "Token is valid!"
  puts "Payload: #{payload}"
rescue => e
  puts "Error: #{e.message}"
end

Using Environment Variables

Create a .env file in your project root:

FRONTEGG_DOMAIN=your-frontegg-domain
FRONTEGG_TOKEN=your-jwt-token

Then use the example script:

ruby examples/validate_token.rb

Development

After checking out the repo, run bundle install to install dependencies.

Running Tests

Run the test suite:

bundle exec rspec

How it Works

1. The validator fetches the JSON Web Key Set (JWKS) from Frontegg's well-known OIDC endpoint
2. It extracts the appropriate signing key based on the token's kid (Key ID)
3. The token is validated using the public key
4. If valid, the token payload is returned

Error Handling

The validator will raise exceptions for:

• Invalid tokens
• Missing or invalid JWKS
• Missing or invalid signing keys
• Network errors when fetching JWKS

Security Notes

• Always validate tokens in a secure environment
• Keep your tokens secure and never expose them in logs or error messages
• Use HTTPS for all communications
• Regularly update the JWKS as keys may rotate

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/yourusername/frontegg_jwt_validator.

License

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