    # File lib/chef/streaming_cookbook_uploader.rb, line 29
          def make_request(http_verb, to_url, user_id, secret_key_filename, params = {}, headers = {})
            boundary = '----RubyMultipartClient' + rand(1000000).to_s + 'ZZZZZ'
            parts = []
            content_file = nil

            timestamp = Time.now.utc.iso8601
            secret_key = OpenSSL::PKey::RSA.new(File.read(secret_key_filename))

            unless params.nil? || params.empty?
              params.each do |key, value|
                if value.kind_of?(File)
                  content_file = value
                  filepath = value.path
                  filename = File.basename(filepath)
                  parts << StringPart.new( "--" + boundary + "\r\n" +
                                           "Content-Disposition: form-data; name=\"" + key.to_s + "\"; filename=\"" + filename + "\"\r\n" +
                                           "Content-Type: application/octet-stream\r\n\r\n")
                  parts << StreamPart.new(value, File.size(filepath))
                  parts << StringPart.new("\r\n")
                else
                  parts << StringPart.new( "--" + boundary + "\r\n" +
                                           "Content-Disposition: form-data; name=\"" + key.to_s + "\"\r\n\r\n")
                  parts << StringPart.new(value.to_s + "\r\n")
                end
              end
              parts << StringPart.new("--" + boundary + "--\r\n")
            end

            body_stream = MultipartStream.new(parts)

            timestamp = Time.now.utc.iso8601

            url = URI.parse(to_url)

            Chef::Log.logger.debug("Signing: method: #{http_verb}, path: #{url.path}, file: #{content_file}, User-id: #{user_id}, Timestamp: #{timestamp}")

            # We use the body for signing the request if the file parameter
            # wasn't a valid file or wasn't included. Extract the body (with
            # multi-part delimiters intact) to sign the request.
            # TODO: tim: 2009-12-28: It'd be nice to remove this special case, and
            # always hash the entire request body. In the file case it would just be
            # expanded multipart text - the entire body of the POST.
            content_body = parts.inject("") { |result,part| result + part.read(0, part.size) }
            content_file.rewind if content_file # we consumed the file for the above operation, so rewind it.

            signing_options = {
              :http_method=>http_verb,
              :path=>url.path,
              :user_id=>user_id,
              :timestamp=>timestamp}
            (content_file && signing_options[:file] = content_file) || (signing_options[:body] = (content_body || ""))

            headers.merge!(Mixlib::Authentication::SignedHeaderAuth.signing_object(signing_options).sign(secret_key))

            content_file.rewind if content_file

            # net/http doesn't like symbols for header keys, so we'll to_s each one just in case
            headers = DefaultHeaders.merge(Hash[*headers.map{ |k,v| [k.to_s, v] }.flatten])

            req = case http_verb
                  when :put
                    Net::HTTP::Put.new(url.path, headers)
                  when :post
                    Net::HTTP::Post.new(url.path, headers)
                  end
            req.content_length = body_stream.size
            req.content_type = 'multipart/form-data; boundary=' + boundary unless parts.empty?
            req.body_stream = body_stream

            http = Net::HTTP.new(url.host, url.port)
            if url.scheme == "https"
              http.use_ssl = true
              http.verify_mode = OpenSSL::SSL::VERIFY_NONE
            end
            res = http.request(req)
            #res = http.start {|http_proc| http_proc.request(req) }

            # alias status to code and to_s to body for test purposes
            # TODO: stop the following madness!
            class << res
              alias :to_s :body

              # BUGBUG this makes the response compatible with what respsonse_steps expects to test headers (response.headers[] -> response[])
              def headers
                self
              end

              def status
                code.to_i
              end
            end
            res
          end