# File lib/gdata/auth/authsub.rb, line 79
      def sign_request!(request)
        header = "AuthSub token=\"#{@token}\""
        
        if @private_key
          time = Time.now.to_i
          nonce = OpenSSL::BN.rand_range(BIG_INT_MAX)
          method = request.method.to_s.upcase
          data = "#{method} #{request.url} #{time} #{nonce}"
          sig = @private_key.sign(OpenSSL::Digest::SHA1.new, data)
          sig = Base64.encode64(sig).gsub(/\n/, '')
          header = "#{header} sigalg=\"rsa-sha1\" data=\"#{data}\""
          header = "#{header} sig=\"#{sig}\""
        end
        
        request.headers['Authorization'] = header
      end