Contents

require 'jwt'

require_relative 'jwks'

module SMARTAppLaunch
  class ClientAssertionBuilder
    def self.build(...)
      new(...).client_assertion
    end

    attr_reader :aud,
                :client_assertion_type,
                :content_type,
                :client_auth_encryption_method,
                :exp,
                :grant_type,
                :iss,
                :jti,
                :sub,
                :kid

    def initialize(
      client_auth_encryption_method:,
      iss:,
      sub:,
      aud:,
      exp: 5.minutes.from_now.to_i,
      jti: SecureRandom.hex(32),
      kid: nil
    )
      @client_auth_encryption_method = client_auth_encryption_method
      @iss = iss
      @sub = sub
      @aud = aud
      @content_type = content_type
      @grant_type = grant_type
      @client_assertion_type = client_assertion_type
      @exp = exp
      @jti = jti
      @kid = kid
    end

    def private_key
      @private_key ||= JWKS.jwks
        .select { |key| key[:key_ops]&.include?('sign') }
        .select { |key| key[:alg] == client_auth_encryption_method }
        .find { |key| !kid || key[:kid] == kid }
    end

    def jwt_payload
      { iss:, sub:, aud:, exp:, jti: }.compact
    end

    def signing_key
      private_key()
      if @private_key.nil?
        raise Inferno::Exceptions::AssertionException, "No signing key found for inputs: encryption method = '#{client_auth_encryption_method}' and kid = '#{kid}'"
      end
      return @private_key.signing_key
    end

    def key_id
      @private_key['kid']
    end

    def client_assertion
      @client_assertion ||=
        JWT.encode jwt_payload, signing_key, client_auth_encryption_method, { alg: client_auth_encryption_method, kid: key_id, typ: 'JWT' }
    end
  end
end

Version data entries

8 entries across 8 versions & 1 rubygems

Version	Path
smart_app_launch_test_kit-0.5.1	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.5.0	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.6	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.5	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.4	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.3	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.2	lib/smart_app_launch/client_assertion_builder.rb
smart_app_launch_test_kit-0.4.1	lib/smart_app_launch/client_assertion_builder.rb