build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/k8s.io/apiserver/pkg/util/x509metrics/server_cert_deprecations.go

@@ -0,0 +1,225 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package x509metrics
+
+import (
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net/http"
+	"reflect"
+	"strings"
+
+	utilnet "k8s.io/apimachinery/pkg/util/net"
+	"k8s.io/apiserver/pkg/audit"
+	"k8s.io/component-base/metrics"
+	"k8s.io/klog/v2"
+)
+
+var _ utilnet.RoundTripperWrapper = &x509DeprecatedCertificateMetricsRTWrapper{}
+
+type x509DeprecatedCertificateMetricsRTWrapper struct {
+	rt http.RoundTripper
+
+	checkers []deprecatedCertificateAttributeChecker
+}
+
+type deprecatedCertificateAttributeChecker interface {
+	// CheckRoundTripError returns true if the err is an error specific
+	// to this deprecated certificate attribute
+	CheckRoundTripError(err error) bool
+	// CheckPeerCertificates returns true if the deprecated attribute/value pair
+	// was found in a given certificate in the http.Response.TLS.PeerCertificates bundle
+	CheckPeerCertificates(certs []*x509.Certificate) bool
+	// IncreaseCounter increases the counter internal to this interface
+	// Use the req to derive and log information useful for troubleshooting the certificate issue
+	IncreaseMetricsCounter(req *http.Request)
+}
+
+// counterRaiser is a helper structure to include in certificate deprecation checkers.
+// It implements the IncreaseMetricsCounter() method so that, when included in the checker,
+// it does not have to be reimplemented.
+type counterRaiser struct {
+	counter *metrics.Counter
+	// programmatic id used in log and audit annotations prefixes
+	id string
+	// human readable explanation
+	reason string
+}
+
+func (c *counterRaiser) IncreaseMetricsCounter(req *http.Request) {
+	if req != nil && req.URL != nil {
+		if hostname := req.URL.Hostname(); len(hostname) > 0 {
+			prefix := fmt.Sprintf("%s.invalid-cert.kubernetes.io", c.id)
+			klog.Infof("%s: invalid certificate detected connecting to %q: %s", prefix, hostname, c.reason)
+			audit.AddAuditAnnotation(req.Context(), prefix+"/"+hostname, c.reason)
+		}
+	}
+	c.counter.Inc()
+}
+
+// NewDeprecatedCertificateRoundTripperWrapperConstructor returns a RoundTripper wrapper that's usable within ClientConfig.Wrap.
+//
+// It increases the `missingSAN` counter whenever:
+//  1. we get a x509.HostnameError with string `x509: certificate relies on legacy Common Name field`
+//     which indicates an error caused by the deprecation of Common Name field when veryfing remote
+//     hostname
+//  2. the server certificate in response contains no SAN. This indicates that this binary run
+//     with the GODEBUG=x509ignoreCN=0 in env
+//
+// It increases the `sha1` counter whenever:
+//  1. we get a x509.InsecureAlgorithmError with string `SHA1`
+//     which indicates an error caused by an insecure SHA1 signature
+//  2. the server certificate in response contains a SHA1WithRSA or ECDSAWithSHA1 signature.
+//     This indicates that this binary run with the GODEBUG=x509sha1=1 in env
+func NewDeprecatedCertificateRoundTripperWrapperConstructor(missingSAN, sha1 *metrics.Counter) func(rt http.RoundTripper) http.RoundTripper {
+	return func(rt http.RoundTripper) http.RoundTripper {
+		return &x509DeprecatedCertificateMetricsRTWrapper{
+			rt: rt,
+			checkers: []deprecatedCertificateAttributeChecker{
+				NewSANDeprecatedChecker(missingSAN),
+				NewSHA1SignatureDeprecatedChecker(sha1),
+			},
+		}
+	}
+}
+
+func (w *x509DeprecatedCertificateMetricsRTWrapper) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := w.rt.RoundTrip(req)
+
+	if err != nil {
+		for _, checker := range w.checkers {
+			if checker.CheckRoundTripError(err) {
+				checker.IncreaseMetricsCounter(req)
+			}
+		}
+	} else if resp != nil {
+		if resp.TLS != nil && len(resp.TLS.PeerCertificates) > 0 {
+			for _, checker := range w.checkers {
+				if checker.CheckPeerCertificates(resp.TLS.PeerCertificates) {
+					checker.IncreaseMetricsCounter(req)
+				}
+			}
+		}
+	}
+
+	return resp, err
+}
+
+func (w *x509DeprecatedCertificateMetricsRTWrapper) WrappedRoundTripper() http.RoundTripper {
+	return w.rt
+}
+
+var _ deprecatedCertificateAttributeChecker = &missingSANChecker{}
+
+type missingSANChecker struct {
+	counterRaiser
+}
+
+func NewSANDeprecatedChecker(counter *metrics.Counter) *missingSANChecker {
+	return &missingSANChecker{
+		counterRaiser: counterRaiser{
+			counter: counter,
+			id:      "missing-san",
+			reason:  "relies on a legacy Common Name field instead of the SAN extension for subject validation",
+		},
+	}
+}
+
+// CheckRoundTripError returns true when we're running w/o GODEBUG=x509ignoreCN=0
+// and the client reports a HostnameError about the legacy CN fields
+func (c *missingSANChecker) CheckRoundTripError(err error) bool {
+	if err != nil && errors.As(err, &x509.HostnameError{}) && strings.Contains(err.Error(), "x509: certificate relies on legacy Common Name field") {
+		// increase the count of registered failures due to Go 1.15 x509 cert Common Name deprecation
+		return true
+	}
+
+	return false
+}
+
+// CheckPeerCertificates returns true when the server response contains
+// a leaf certificate w/o the SAN extension
+func (c *missingSANChecker) CheckPeerCertificates(peerCertificates []*x509.Certificate) bool {
+	if len(peerCertificates) > 0 {
+		if serverCert := peerCertificates[0]; !hasSAN(serverCert) {
+			return true
+		}
+	}
+
+	return false
+}
+
+func hasSAN(c *x509.Certificate) bool {
+	sanOID := []int{2, 5, 29, 17}
+
+	for _, e := range c.Extensions {
+		if e.Id.Equal(sanOID) {
+			return true
+		}
+	}
+	return false
+}
+
+type sha1SignatureChecker struct {
+	*counterRaiser
+}
+
+func NewSHA1SignatureDeprecatedChecker(counter *metrics.Counter) *sha1SignatureChecker {
+	return &sha1SignatureChecker{
+		counterRaiser: &counterRaiser{
+			counter: counter,
+			id:      "insecure-sha1",
+			reason:  "uses an insecure SHA-1 signature",
+		},
+	}
+}
+
+// CheckRoundTripError returns true when we're running w/o GODEBUG=x509sha1=1
+// and the client reports an InsecureAlgorithmError about a SHA1 signature
+func (c *sha1SignatureChecker) CheckRoundTripError(err error) bool {
+	var unknownAuthorityError x509.UnknownAuthorityError
+	if err == nil {
+		return false
+	}
+	if !errors.As(err, &unknownAuthorityError) {
+		return false
+	}
+
+	errMsg := err.Error()
+	if strIdx := strings.Index(errMsg, "x509: cannot verify signature: insecure algorithm"); strIdx != -1 && strings.Contains(errMsg[strIdx:], "SHA1") {
+		// increase the count of registered failures due to Go 1.18 x509 sha1 signature deprecation
+		return true
+	}
+
+	return false
+}
+
+// CheckPeerCertificates returns true when the server response contains
+// a non-root non-self-signed  certificate with a deprecated SHA1 signature
+func (c *sha1SignatureChecker) CheckPeerCertificates(peerCertificates []*x509.Certificate) bool {
+	// check all received non-self-signed certificates for deprecated signing algorithms
+	for _, cert := range peerCertificates {
+		if cert.SignatureAlgorithm == x509.SHA1WithRSA || cert.SignatureAlgorithm == x509.ECDSAWithSHA1 {
+			// the SHA-1 deprecation does not involve self-signed root certificates
+			if !reflect.DeepEqual(cert.Issuer, cert.Subject) {
+				return true
+			}
+		}
+	}
+
+	return false
+}