crypto/tls: extract certificate validation for the client

Moved some code and added a comment in preparation for extending the TLS
1.3 client with certificate validation. No functional change.
This commit is contained in:
Peter Wu 2017-09-15 18:30:24 +01:00
parent 9e25a0a25d
commit 928e35b73a

View File

@ -350,6 +350,61 @@ func (hs *clientHandshakeState) pickCipherSuite() error {
return nil
}
// processCertsFromServer takes a chain of server certificates from a
// Certificate message and verifies them.
func (hs *clientHandshakeState) processCertsFromServer(certificates [][]byte) error {
c := hs.c
certs := make([]*x509.Certificate, len(certificates))
for i, asn1Data := range certificates {
cert, err := x509.ParseCertificate(asn1Data)
if err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to parse certificate from server: " + err.Error())
}
certs[i] = cert
}
if !c.config.InsecureSkipVerify {
opts := x509.VerifyOptions{
Roots: c.config.RootCAs,
CurrentTime: c.config.time(),
DNSName: c.config.ServerName,
Intermediates: x509.NewCertPool(),
}
for i, cert := range certs {
if i == 0 {
continue
}
opts.Intermediates.AddCert(cert)
}
var err error
c.verifiedChains, err = certs[0].Verify(opts)
if err != nil {
c.sendAlert(alertBadCertificate)
return err
}
}
if c.config.VerifyPeerCertificate != nil {
if err := c.config.VerifyPeerCertificate(certificates, c.verifiedChains); err != nil {
c.sendAlert(alertBadCertificate)
return err
}
}
switch certs[0].PublicKey.(type) {
case *rsa.PublicKey, *ecdsa.PublicKey:
break
default:
c.sendAlert(alertUnsupportedCertificate)
return fmt.Errorf("tls: server's certificate contains an unsupported type of public key: %T", certs[0].PublicKey)
}
c.peerCertificates = certs
return nil
}
func (hs *clientHandshakeState) doFullHandshake() error {
c := hs.c
@ -367,53 +422,9 @@ func (hs *clientHandshakeState) doFullHandshake() error {
if c.handshakes == 0 {
// If this is the first handshake on a connection, process and
// (optionally) verify the server's certificates.
certs := make([]*x509.Certificate, len(certMsg.certificates))
for i, asn1Data := range certMsg.certificates {
cert, err := x509.ParseCertificate(asn1Data)
if err != nil {
c.sendAlert(alertBadCertificate)
return errors.New("tls: failed to parse certificate from server: " + err.Error())
}
certs[i] = cert
if err := hs.processCertsFromServer(certMsg.certificates); err != nil {
return err
}
if !c.config.InsecureSkipVerify {
opts := x509.VerifyOptions{
Roots: c.config.RootCAs,
CurrentTime: c.config.time(),
DNSName: c.config.ServerName,
Intermediates: x509.NewCertPool(),
}
for i, cert := range certs {
if i == 0 {
continue
}
opts.Intermediates.AddCert(cert)
}
c.verifiedChains, err = certs[0].Verify(opts)
if err != nil {
c.sendAlert(alertBadCertificate)
return err
}
}
if c.config.VerifyPeerCertificate != nil {
if err := c.config.VerifyPeerCertificate(certMsg.certificates, c.verifiedChains); err != nil {
c.sendAlert(alertBadCertificate)
return err
}
}
switch certs[0].PublicKey.(type) {
case *rsa.PublicKey, *ecdsa.PublicKey:
break
default:
c.sendAlert(alertUnsupportedCertificate)
return fmt.Errorf("tls: server's certificate contains an unsupported type of public key: %T", certs[0].PublicKey)
}
c.peerCertificates = certs
} else {
// This is a renegotiation handshake. We require that the
// server's identity (i.e. leaf certificate) is unchanged and