Function signedMessage

auth.go:82–95

signedMessage returns the pre-hashed (if necessary) message to be signed by certificate keys in TLS 1.3. See RFC 8446, Section 4.4.3.

(sigHash crypto.Hash, context string, transcript hash.Hash)

// signedMessage returns the pre-hashed (if necessary) message to be signed by
// certificate keys in TLS 1.3. See RFC 8446, Section 4.4.3.
func signedMessage(sigHash crypto.Hash, context string, transcript hash.Hash) []byte {
	if sigHash == directSigning {
		b := &bytes.Buffer{}
		b.Write(signaturePadding)
		io.WriteString(b, context)
		b.Write(transcript.Sum(nil))
		return b.Bytes()
	}
	h := sigHash.New()
	h.Write(signaturePadding)
	io.WriteString(h, context)
	h.Write(transcript.Sum(nil))
	return h.Sum(nil)
}

// typeAndHashFromSignatureScheme returns the corresponding signature type and
// crypto.Hash for a given TLS SignatureScheme.