} {
		b, err := hex.DecodeString(tc.list)
		if err != nil {
			t.Fatal(err)
		}
		configs, err := parseECHConfigList(b)
		if err != nil {
			t.Fatal(err)
		}
		if len(configs) != tc.numConfigs {
			t.Fatalf("unexpected number of configs parsed: got %d want %d", len(configs), tc.numConfigs)
		}
	}

}

	Extensions    []echExtension
}

var errMalformedECHConfig = errors.New("tls: malformed ECHConfigList")

// parseECHConfigList parses a draft-ietf-tls-esni-18 ECHConfigList, returning a
// slice of parsed ECHConfigs, in the same order they were parsed, or an error
// if the list is malformed.
func parseECHConfigList(data []byte) ([]echConfig, error) {
	s := cryptobyte.String(data)
	// Skip the length prefix
	var length uint16

		if c.config.MaxVersion != 0 && c.config.MaxVersion <= VersionTLS12 {
			return nil, nil, nil, errors.New("tls: MaxVersion must be >= VersionTLS13 if EncryptedClientHelloConfigList is populated")
		}
		echConfigs, err := parseECHConfigList(c.config.EncryptedClientHelloConfigList)
		if err != nil {
			return nil, nil, nil, err
		}
		echConfig := pickECHConfig(echConfigs)
		if echConfig == nil {