Encrypt a file using RoR Utilities

decrypt_file_using_ror_utilities.rb

content_path = Rails.root.join('secret_content_file.txt.enc')

encrypted_file = ActiveSupport::EncryptedFile.new(
  content_path: content_path,
  key_path: Rails.application.config.credentials.key_path,
  env_key: "RAILS_MASTER_KEY",
  raise_if_missing_key: true
)

contents = encrypted_file.read

File.write(content_path.to_s.gsub(/\.enc\z/, ""), contents)