// HelloRetryRequest. See RFC 8446, Section 4.4.1.
	if err := transcriptMsg(hs.clientHello, hs.transcript); err != nil {
		return nil, err
	}
	chHash := hs.transcript.Sum(nil)
	hs.transcript.Reset()
	hs.transcript.Write([]byte{typeMessageHash, 0, 0, uint8(len(chHash))})
	hs.transcript.Write(chHash)

	helloRetryRequest := &serverHelloMsg{
		vers:              hs.hello.vers,
		random:            helloRetryRequestRandom,