Function legacyTypeAndHashFromPublicKey

auth.go:132–147

legacyTypeAndHashFromPublicKey returns the fixed signature type and crypto.Hash for a given public key used with TLS 1.0 and 1.1, before the introduction of signature algorithm negotiation.

(pub crypto.PublicKey)

// a given public key used with TLS 1.0 and 1.1, before the introduction of
// signature algorithm negotiation.
func legacyTypeAndHashFromPublicKey(pub crypto.PublicKey) (sigType uint8, hash crypto.Hash, err error) {
	switch pub.(type) {
	case *rsa.PublicKey:
		return signaturePKCS1v15, crypto.MD5SHA1, nil
	case *ecdsa.PublicKey:
		return signatureECDSA, crypto.SHA1, nil
	case ed25519.PublicKey:
		// RFC 8422 specifies support for Ed25519 in TLS 1.0 and 1.1,
		// but it requires holding on to a handshake transcript to do a
		// full signature, and not even OpenSSL bothers with the
		// complexity, so we can't even test it properly.
		return 0, 0, fmt.Errorf("tls: Ed25519 public keys are not supported before TLS 1.2")
	default:
		return 0, 0, fmt.Errorf("tls: unsupported public key: %T", pub)
	}
}

var rsaSignatureSchemes = []struct {
	scheme          SignatureScheme