vendor: bump k8s to v0.25.4

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/k8s.io/client-go/transport/transport.go

@@ -24,6 +24,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"reflect"
 	"sync"
 	"time"
 
@@ -39,6 +40,10 @@ func New(config *Config) (http.RoundTripper, error) {
 		return nil, fmt.Errorf("using a custom transport with TLS certificate options or the insecure flag is not allowed")
 	}
 
+	if !isValidHolders(config) {
+		return nil, fmt.Errorf("misconfigured holder for dialer or cert callback")
+	}
+
 	var (
 		rt  http.RoundTripper
 		err error
@@ -56,6 +61,26 @@ func New(config *Config) (http.RoundTripper, error) {
 	return HTTPWrappersForConfig(config, rt)
 }
 
+func isValidHolders(config *Config) bool {
+	if config.TLS.GetCertHolder != nil {
+		if config.TLS.GetCertHolder.GetCert == nil ||
+			config.TLS.GetCert == nil ||
+			reflect.ValueOf(config.TLS.GetCertHolder.GetCert).Pointer() != reflect.ValueOf(config.TLS.GetCert).Pointer() {
+			return false
+		}
+	}
+
+	if config.DialHolder != nil {
+		if config.DialHolder.Dial == nil ||
+			config.Dial == nil ||
+			reflect.ValueOf(config.DialHolder.Dial).Pointer() != reflect.ValueOf(config.Dial).Pointer() {
+			return false
+		}
+	}
+
+	return true
+}
+
 // TLSConfigFor returns a tls.Config that will provide the transport level security defined
 // by the provided Config. Will return nil if no transport level security is requested.
 func TLSConfigFor(c *Config) (*tls.Config, error) {