# File lib/mixlib/authentication/signedheaderauth.rb, line 212
      def canonicalize_request(sign_algorithm = algorithm, sign_version = proto_version)
        digest = validate_sign_version_digest!(sign_algorithm, sign_version)
        canonical_x_ops_user_id = canonicalize_user_id(user_id, sign_version, digest)
        case sign_version
        when "1.3"
          [
            "Method:#{http_method.to_s.upcase}",
            "Path:#{canonical_path}",
            "X-Ops-Content-Hash:#{hashed_body(digest)}",
            "X-Ops-Sign:version=#{sign_version}",
            "X-Ops-Timestamp:#{canonical_time}",
            "X-Ops-UserId:#{canonical_x_ops_user_id}",
            "X-Ops-Server-API-Version:#{server_api_version}",
          ].join("\n")
        else
          [
            "Method:#{http_method.to_s.upcase}",
            "Hashed Path:#{digester.hash_string(canonical_path, digest)}",
            "X-Ops-Content-Hash:#{hashed_body(digest)}",
            "X-Ops-Timestamp:#{canonical_time}",
            "X-Ops-UserId:#{canonical_x_ops_user_id}",
          ].join("\n")
        end
      end