# Load public key
    public_key_env_var = opts[:public_key_env_var]

    if opts[:public_key_env_var]
      public_key = OpenSSL::X509::Certificate.new(ENV[public_key_env_var])
      debug("Using public key from environment variable: #{public_key_env_var}")
    else
      public_key_path = File.expand_path(opts[:public_key], opts[:_boltdir])
      public_key      = OpenSSL::X509::Certificate.new(File.read(public_key_path))
      debug("Using public key at path: #{public_key_path}")
    end

    # Load private key
    private_key_env_var = opts[:private_key_env_var]

    if public_key_env_var
      private_key = OpenSSL::PKey::RSA.new(ENV[private_key_env_var])
      debug("Using private key from environment variable: #{private_key_env_var}")
    else
      private_key_path = File.expand_path(opts[:private_key], opts[:_boltdir])
      private_key      = OpenSSL::PKey::RSA.new(File.read(private_key_path))
      debug("Using private key at path: #{private_key_path}")
    end