CFE-984: Add support for custom CA bundle for reencrypt termination t…

…ype routes

pkg/manifests/assets/router/deployment.yaml

@@ -29,7 +29,7 @@ spec:
           - name: DEFAULT_CERTIFICATE_DIR
             value: /etc/pki/tls/private
           - name: DEFAULT_DESTINATION_CA_PATH
-            value: /var/run/configmaps/service-ca/service-ca.crt
+            value: /var/run/configmaps/ca-trust/ca-bundle.crt
           livenessProbe:
             httpGet:
               path: /healthz
@@ -53,19 +53,19 @@ spec:
           - mountPath: /etc/pki/tls/private
             name: default-certificate
             readOnly: true
-          - mountPath: /var/run/configmaps/service-ca
-            name: service-ca-bundle
+          - mountPath: /var/run/configmaps/ca-trust
+            name: ingress-ca-bundle
             readOnly: true
       volumes:
       - name: default-certificate
         secret:
           defaultMode: 420
           # SecretName is set at run-time.
-      - name: service-ca-bundle
+      - name: ingress-ca-bundle
         configMap:
           items:
-          - key: service-ca.crt
-            path: service-ca.crt
-          name: service-ca-bundle
+          - key: ca-bundle.crt
+            path: ca-bundle.crt
+          name: ingress-ca-bundle
           optional: false
         defaultMode: 420

pkg/operator/controller/cabundle-configmap/cabundle_configmap.go

@@ -0,0 +1,283 @@
+package cabundleconfigmap
+
+import (
+	"bytes"
+	"context"
+	"crypto/x509"
+	"encoding/hex"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+	"reflect"
+	"time"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+)
+
+const (
+	// adminCABundleConfigMapKeyName is the name of the key holding CA certificates
+	// in the admin-ca-bundle.
+	adminCABundleConfigMapKeyName = "ca-bundle.crt"
+
+	// serviceCABundleConfigMapKeyName is the name of the key holding CA certificates
+	// in the service-ca-bundle.
+	serviceCABundleConfigMapKeyName = "service-ca.crt"
+
+	// ingressCABundleConfigMapKeyName is the name of the key holding CA certificates
+	// in the ingress-ca-bundle.
+	ingressCABundleConfigMapKeyName = "ca-bundle.crt"
+)
+
+var (
+	// insecureCertificateSignatureAlgorithms is used to warn about and
+	// filter out certificates that use algorithms that are no longer
+	// supported by OpenSSL. Configuring the router with a certificate that
+	// used one of these algorithms would cause HAProxy to refuse to start.
+	insecureCertificateSignatureAlgorithms = map[x509.SignatureAlgorithm]string{
+		x509.UnknownSignatureAlgorithm: "UnknownSignatureAlgorithm",
+		x509.MD2WithRSA:                "MD2WithRSA",
+		x509.MD5WithRSA:                "MD5WithRSA",
+		x509.SHA1WithRSA:               "SHA1WithRSA",
+		x509.DSAWithSHA1:               "DSAWithSHA1",
+		x509.DSAWithSHA256:             "DSAWithSHA256",
+		x509.ECDSAWithSHA1:             "ECDSAWithSHA1",
+	}
+)
+
+// ensureIngressCABundleConfigMap syncs ingress CA bundle configmap. Returns
+// an error value.
+func (r *reconciler) ensureIngressCABundleConfigMap(ctx context.Context) error {
+	have, current, err := r.currentConfigMap(ctx, r.config.IngressCAConfigMapName)
+	if err != nil {
+		return err
+	}
+
+	want, desired, err := r.desiredIngressCABundleConfigMap(ctx)
+	if err != nil {
+		return err
+	}
+
+	switch {
+	case want && !have:
+		if err := r.client.Create(ctx, desired); err != nil {
+			return fmt.Errorf("failed to create %s configmap: %w", desired.Name, err)
+		}
+		log.Info("created configmap", "namespace", desired.Namespace, "name", desired.Name)
+		return nil
+	case want && have:
+		if updated, err := r.updateCABundleConfigMap(ctx, current, desired); err != nil {
+			return fmt.Errorf("failed to update %s configmap: %w", desired.Name, err)
+		} else if updated {
+			log.Info("updated configmap", "namespace", desired.Namespace, "name", desired.Name)
+			return nil
+		}
+	}
+	return nil
+}
+
+// desiredIngressCABundleConfigMap returns the desired ingress CA bundle configmap. Returns a
+// Boolean indicating whether a configmap is desired, the configmap if one is desired and
+// an error value.
+func (r *reconciler) desiredIngressCABundleConfigMap(ctx context.Context) (bool, *corev1.ConfigMap, error) {
+	_, adminCABundle, err := r.currentConfigMap(ctx, r.config.AdminCAConfigMapName)
+	if err != nil {
+		return false, nil, err
+	}
+
+	exist, serviceCABundle, err := r.currentConfigMap(ctx, r.config.ServiceCAConfigMapName)
+	if err != nil {
+		return false, nil, err
+	}
+	// Earlier implementation where, defaultDestinationCA had just OpenShift service CA and
+	// required service-ca-bundle to exist for the router deployment to start. And to keep
+	// the same behavior ingress-ca-bundle will not be created when service-ca-bundle does not exist.
+	if !exist {
+		return false, nil, fmt.Errorf("openshift service CA bundle does not exist, name: %+v", r.config.ServiceCAConfigMapName)
+	}
+
+	ingressCABundleData := make(map[string]string, 1)
+	certBuffer := new(bytes.Buffer)
+	if serviceCABundle != nil {
+		if serviceCABundle.Data == nil {
+			return false, nil, fmt.Errorf("%s does not contain any config data", serviceCABundle.Name)
+		}
+		data, exist := serviceCABundle.Data[serviceCABundleConfigMapKeyName]
+		if !exist {
+			return false, nil, fmt.Errorf("%s does not contain \"%s\" key", serviceCABundle.Name, serviceCABundleConfigMapKeyName)
+		}
+		parsedCerts, validCerts, err := r.sanitizeCACertificateBundle(serviceCABundle.Name, []byte(data), certBuffer)
+		if err != nil {
+			return false, nil, fmt.Errorf("failed to validate %s config data", serviceCABundle.Name)
+		}
+		log.Info("successfully validated CA certificate bundle", "name", serviceCABundle.Name, "parsed certificates count", parsedCerts, "discarded certificates count", parsedCerts-validCerts)
+	}
+	if adminCABundle != nil && adminCABundle.Data != nil {
+		data, exist := adminCABundle.Data[adminCABundleConfigMapKeyName]
+		if exist {
+			parsedCerts, validCerts, err := r.sanitizeCACertificateBundle(adminCABundle.Name, []byte(data), certBuffer)
+			if err != nil {
+				r.eventRecorder.Warningf("CABundleValidation", "failed to validate %s config data: %v", adminCABundle.Name, err)
+			}
+			log.Info("successfully validated CA certificate bundle", "name", adminCABundle.Name, "parsed certificates count", parsedCerts, "discarded certificates count", parsedCerts-validCerts)
+		} else {
+			r.eventRecorder.Warningf("CABundleValidation", "%s is invalid, must contain \"%s\" key with required CA certificates", adminCABundle.Name, adminCABundleConfigMapKeyName)
+		}
+	}
+	ingressCABundleData[ingressCABundleConfigMapKeyName] = certBuffer.String()
+
+	ingressCABundleName := r.config.IngressCAConfigMapName
+	cm := corev1.ConfigMap{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      ingressCABundleName.Name,
+			Namespace: ingressCABundleName.Namespace,
+		},
+		Data: ingressCABundleData,
+	}
+	return true, &cm, nil
+}
+
+// currentConfigMap returns the current named configmap. Returns a Boolean
+// indicating whether the configmap existed, the configmap if it did exist,
+// and an error value.
+func (r *reconciler) currentConfigMap(ctx context.Context, name types.NamespacedName) (bool, *corev1.ConfigMap, error) {
+	var cm corev1.ConfigMap
+	if err := r.client.Get(ctx, name, &cm); err != nil {
+		if errors.IsNotFound(err) {
+			return false, nil, nil
+		}
+		return false, nil, err
+	}
+	return true, &cm, nil
+}
+
+// updateCABundleConfigMap updates a configmap. Returns a Boolean indicating
+// whether the configmap was updated, and an error value.
+func (r *reconciler) updateCABundleConfigMap(ctx context.Context, current, desired *corev1.ConfigMap) (bool, error) {
+	if caBundleConfigmapsEqual(current, desired) {
+		return false, nil
+	}
+	updated := current.DeepCopy()
+	updated.Data = desired.Data
+	if err := r.client.Update(ctx, updated); err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// caBundleConfigmapsEqual compares two CA bundle configmaps.  Returns true if
+// the configmaps should be considered equal for the purpose of determining
+// whether an update is necessary, false otherwise.
+func caBundleConfigmapsEqual(a, b *corev1.ConfigMap) bool {
+	return reflect.DeepEqual(a.Data, b.Data)
+}
+
+// encodeSerialNumber encodes certificate serial number back into hex format
+// which was decoded during certificate parsing. Serial number is encoded to
+// exact representation as observed in the certificates to make certificate
+// identification easier.
+func encodeSerialNumber(serialNumber big.Int) string {
+	var serialNumberWithColon string
+	serialNumberStr := hex.EncodeToString(serialNumber.Bytes())
+	for i := 0; i < len(serialNumberStr); i++ {
+		if i != 0 && i%2 == 0 {
+			serialNumberWithColon += ":"
+		}
+		serialNumberWithColon += string(serialNumberStr[i])
+	}
+	return serialNumberWithColon
+}
+
+// getCertificatePrintId returns an identifier in the format
+// <Certificate SerialNumber>(SerialNumber)-<Certificate CommonName>(CommonName)
+// which is used in logging and for better identification of the certificate in
+// the bundle.  For example:
+// 44:81:8b:e8:69:bd:69:34:5c:7e:9c:66:83:ec:01:6c:3e:79:51:9d(SerialNumber)-admin-ca(CommonName)
+// certificate in the bundle.
+func getCertificatePrintId(cert *x509.Certificate) string {
+	return fmt.Sprintf("%s(SerialNumber)-%s(CommonName)", encodeSerialNumber(*cert.SerialNumber), cert.Subject.CommonName)
+}
+
+// sanitizeCACertificateBundle validates all the certificates present in the CA
+// bundle, removing duplicates.
+func (r *reconciler) sanitizeCACertificateBundle(caCertBundleName string, caCertBundle []byte, certBuffer *bytes.Buffer) (int, int, error) {
+	// Parse PEM data.
+	parsedCerts := make([]*x509.Certificate, 0)
+	for block, rest := pem.Decode(caCertBundle); block != nil; block, rest = pem.Decode(rest) {
+		switch block.Type {
+		case "CERTIFICATE":
+			cert, err := x509.ParseCertificate(block.Bytes)
+			if err != nil {
+				return len(parsedCerts), 0, fmt.Errorf("failed to parse CA certificate in %s bundle: %w", caCertBundleName, err)
+			}
+			parsedCerts = append(parsedCerts, cert)
+		default:
+			log.Error(nil, "CA certificate bundle contains non-certificate data, discarded", "ca bundle name", caCertBundleName, "type", block.Type)
+			continue
+		}
+	}
+
+	// Validate certificates.
+	validCerts := make([]*x509.Certificate, 0)
+	for i := range parsedCerts {
+		if skip := r.validateCACertificate(parsedCerts[i], caCertBundleName); !skip {
+			validCerts = append(validCerts, parsedCerts[i])
+		}
+	}
+
+	// Check for duplicates.
+	certMap := map[string]*x509.Certificate{}
+	for i := range validCerts {
+		cert := validCerts[i]
+		k := fmt.Sprintf("%v:%x:%s", *cert.SerialNumber, cert.SubjectKeyId, cert.Subject.CommonName)
+		if _, ok := certMap[k]; ok {
+			log.Error(nil, "duplicate certificates found", "certificate", getCertificatePrintId(cert))
+		} else {
+			certMap[k] = cert
+		}
+	}
+
+	// Marshal valid certificates (including any duplicates) back to PEM.
+	for i := range validCerts {
+		block := &pem.Block{
+			Type:  "CERTIFICATE",
+			Bytes: validCerts[i].Raw,
+		}
+		if err := pem.Encode(certBuffer, block); err != nil {
+			return len(parsedCerts), len(validCerts),
+				fmt.Errorf("failed to encode %s certificate of %s bundle: %w", getCertificatePrintId(validCerts[i]), caCertBundleName, err)
+		}
+	}
+
+	return len(parsedCerts), len(validCerts), nil
+}
+
+// validateCACertificate does below validations on a CA certificate.
+// - Secure Signature Algorithm is made use of for certificate signing.
+// - Certificate Validity.
+// - Certificate is a Certificate Authority.
+func (r *reconciler) validateCACertificate(cert *x509.Certificate, caCertBundleName string) bool {
+	skip := false
+	certID := getCertificatePrintId(cert)
+	if _, ok := insecureCertificateSignatureAlgorithms[cert.SignatureAlgorithm]; ok {
+		r.eventRecorder.Warningf("CABundleValidation", "certificate uses insecure signature algorithm, discarded. { certificate: %s, signature algorithm: %s, certificate bundle: %s }", certID, cert.SignatureAlgorithm.String(), caCertBundleName)
+		skip = true
+	}
+
+	if !cert.IsCA {
+		r.eventRecorder.Warningf("CABundleValidation", "certificate is not a CA certificate, discarded. { certificate: %s, certificate bundle: %s }", certID, caCertBundleName)
+		skip = true
+	}
+
+	curTime := time.Now()
+	if curTime.Sub(cert.NotBefore).Hours() < 0 {
+		r.eventRecorder.Warningf("CABundleValidation", "certificate is not yet valid. { certificate: %s, valid after: %s, certificate bundle: %s }", certID, cert.NotBefore.String(), caCertBundleName)
+	}
+	if curTime.Sub(cert.NotAfter).Hours() > 0 {
+		r.eventRecorder.Warningf("CABundleValidation", "certificate has expired. { certificate: %s, expired on: %s, certificate bundle: %s }", certID, cert.NotAfter.String(), caCertBundleName)
+	}
+
+	return skip
+}