Option to require secure connections from clients when server is configured for SSL/TLS

go/mysql/server.go

@@ -149,6 +149,9 @@ type Listener struct {
 
 	// shutdown indicates that Shutdown method was called.
 	shutdown sync2.AtomicBool
+
+	// RequireSecureTransport configures the server to reject connections from insecure clients
+	RequireSecureTransport bool
 }
 
 // NewFromListener creares a new mysql listener from an existing net.Listener
@@ -317,6 +320,9 @@ func (l *Listener) handle(conn net.Conn, connectionID uint32, acceptTime time.Ti
 			}
 		}
 	} else {
+		if l.RequireSecureTransport {
+			c.writeErrorPacketFromError(fmt.Errorf("Server does not allow insecure connections, client must use SSL/TLS"))
+		}
 		connCountByTLSVer.Add(versionNoTLS, 1)
 		defer connCountByTLSVer.Add(versionNoTLS, -1)
 	}

go/mysql/server_test.go

@@ -937,6 +937,86 @@ func TestTLSServer(t *testing.T) {
 
 }
 
+// TestTLSRequired creates a Server with TLS required, then tests that an insecure mysql
+// client is rejected
+func TestTLSRequired(t *testing.T) {
+	th := &testHandler{}
+
+	authServer := NewAuthServerStatic()
+	authServer.Entries["user1"] = []*AuthServerStaticEntry{{
+		Password: "password1",
+	}}
+
+	// Create the listener, so we can get its host.
+	// Below, we are enabling --ssl-verify-server-cert, which adds
+	// a check that the common name of the certificate matches the
+	// server host name we connect to.
+	l, err := NewListener("tcp", ":0", authServer, th, 0, 0)
+	if err != nil {
+		t.Fatalf("NewListener failed: %v", err)
+	}
+	defer l.Close()
+
+	// Make sure hostname is added as an entry to /etc/hosts, otherwise ssl handshake will fail
+	host, err := os.Hostname()
+	if err != nil {
+		t.Fatalf("Failed to get os Hostname: %v", err)
+	}
+
+	port := l.Addr().(*net.TCPAddr).Port
+
+	// Create the certs.
+	root, err := ioutil.TempDir("", "TestTLSRequired")
+	if err != nil {
+		t.Fatalf("TempDir failed: %v", err)
+	}
+	defer os.RemoveAll(root)
+	tlstest.CreateCA(root)
+	tlstest.CreateSignedCert(root, tlstest.CA, "01", "server", host)
+
+	// Create the server with TLS config.
+	serverConfig, err := vttls.ServerConfig(
+		path.Join(root, "server-cert.pem"),
+		path.Join(root, "server-key.pem"),
+		path.Join(root, "ca-cert.pem"))
+	if err != nil {
+		t.Fatalf("TLSServerConfig failed: %v", err)
+	}
+	l.TLSConfig = serverConfig
+	l.RequireSecureTransport = true
+	go l.Accept()
+
+	// Setup conn params without SSL.
+	params := &ConnParams{
+		Host:  host,
+		Port:  port,
+		Uname: "user1",
+		Pass:  "password1",
+	}
+	conn, err := Connect(context.Background(), params)
+	if err == nil {
+		t.Fatal("mysql should have failed")
+	}
+	if conn != nil {
+		conn.Close()
+	}
+
+	// setup conn params with TLS
+	tlstest.CreateSignedCert(root, tlstest.CA, "02", "client", "Client Cert")
+	params.Flags = CapabilityClientSSL
+	params.SslCa = path.Join(root, "ca-cert.pem")
+	params.SslCert = path.Join(root, "client-cert.pem")
+	params.SslKey = path.Join(root, "client-key.pem")
+
+	conn, err = Connect(context.Background(), params)
+	if err != nil {
+		t.Fatalf("mysql failed: %v", err)
+	}
+	if conn != nil {
+		conn.Close()
+	}
+}
+
 func checkCountForTLSVer(t *testing.T, version string, expected int64) {
 	connCounts := connCountByTLSVer.Counts()
 	count, ok := connCounts[version]

go/vt/vtgate/plugin_mysql_server.go

@@ -48,6 +48,8 @@ var (
 	mysqlAllowClearTextWithoutTLS = flag.Bool("mysql_allow_clear_text_without_tls", false, "If set, the server will allow the use of a clear text password over non-SSL connections.")
 	mysqlServerVersion            = flag.String("mysql_server_version", mysql.DefaultServerVersion, "MySQL server version to advertise.")
 
+	mysqlServerRequireSecureTransport = flag.Bool("mysql_server_require_secure_transport", false, "Reject insecure connections but only if mysql_server_ssl_cert and mysql_server_ssl_key are provided")
+
 	mysqlSslCert = flag.String("mysql_server_ssl_cert", "", "Path to the ssl cert for mysql server plugin SSL")
 	mysqlSslKey  = flag.String("mysql_server_ssl_key", "", "Path to ssl key for mysql server plugin SSL")
 	mysqlSslCa   = flag.String("mysql_server_ssl_ca", "", "Path to ssl CA for mysql server plugin SSL. If specified, server will require and validate client certs.")
@@ -212,9 +214,9 @@ func initMySQLProtocol() {
 				log.Exitf("grpcutils.TLSServerConfig failed: %v", err)
 				return
 			}
+			mysqlListener.RequireSecureTransport = *mysqlServerRequireSecureTransport
 		}
 		mysqlListener.AllowClearTextWithoutTLS = *mysqlAllowClearTextWithoutTLS
-
 		// Check for the connection threshold
 		if *mysqlSlowConnectWarnThreshold != 0 {
 			log.Infof("setting mysql slow connection threshold to %v", mysqlSlowConnectWarnThreshold)