PKCS8 private keys for CA issuers

hack/check-cert-secret.sh

@@ -52,10 +52,10 @@ prepareParts()
     # extract certificate from certificate secret
     kubectl -n $NS get secret $(kubectl -n $NS get certificates.cert.gardener.cloud $CERTNAME  -o=jsonpath='{.spec.secretRef.name}') -o=jsonpath='{.data.tls\.crt}' | base64 -d > "$X509CERT"
 
+    CSPLIT=gcsplit # use gnu csplit on mac (install with "brew install coreutils")
+    which $CSPLIT || export CSPLIT=csplit
     # split certificate and chain
-
-    #cat $X509CERT | awk -v PREFIX="$PREFIX" 'split_after == 1 {n++;split_after=0} /-----END CERTIFICATE-----/ {split_after=1} {print >  (PREFIX "cert" n ".pem")}'
-    csplit -s -z -f "$PREFIX/cert-" -b "%d.pem" $X509CERT '/-----BEGIN CERTIFICATE-----/' '{*}'
+    $CSPLIT -s -z -f "$PREFIX/cert-" -b "%d.pem" $X509CERT '/-----BEGIN CERTIFICATE-----/' '{*}'
 }
 
 cleanup()

pkg/cert/legobridge/cakeypair_test.go

@@ -0,0 +1,85 @@
+/*
+ * SPDX-FileCopyrightText: 2022 SAP SE or an SAP affiliate company and Gardener contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package legobridge
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"math/big"
+	"time"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	corev1 "k8s.io/api/core/v1"
+)
+
+var _ = Describe("PKI Helpers", func() {
+	Context("CAKeyPairFromSecretData", func() {
+		It("works for ec key", func() {
+			priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+			Expect(err).To(Succeed())
+			keyBytes, err := x509.MarshalECPrivateKey(priv)
+			Expect(err).To(Succeed())
+			data, err := createCertificate(priv, priv.Public(), "EC PRIVATE KEY", keyBytes)
+			Expect(err).To(Succeed())
+
+			_, err = CAKeyPairFromSecretData(data)
+			Expect(err).To(Succeed())
+		})
+
+		It("works for PKCS1 rsa key", func() {
+			priv, err := rsa.GenerateKey(rand.Reader, 2048)
+			Expect(err).To(Succeed())
+			keyBytes := x509.MarshalPKCS1PrivateKey(priv)
+			data, err := createCertificate(priv, priv.Public(), "RSA PRIVATE KEY", keyBytes)
+			Expect(err).To(Succeed())
+
+			_, err = CAKeyPairFromSecretData(data)
+			Expect(err).To(Succeed())
+		})
+
+		It("works for PKCS8 rsa key", func() {
+			priv, err := rsa.GenerateKey(rand.Reader, 2048)
+			Expect(err).To(Succeed())
+			keyBytes, err := x509.MarshalPKCS8PrivateKey(priv)
+			Expect(err).To(Succeed())
+			data, err := createCertificate(priv, priv.Public(), "PRIVATE KEY", keyBytes)
+			Expect(err).To(Succeed())
+
+			_, err = CAKeyPairFromSecretData(data)
+			Expect(err).To(Succeed())
+		})
+	})
+})
+
+func createCertificate(privKey crypto.PrivateKey, pubKey crypto.PublicKey, header string, privKeyBytes []byte) (map[string][]byte, error) {
+	template := &x509.Certificate{
+		SerialNumber:          big.NewInt(1234),
+		Subject:               pkix.Name{CommonName: "example.com"},
+		NotBefore:             time.Now(),
+		NotAfter:              time.Now().Add(time.Hour * 24 * 365),
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+	}
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, template, pubKey, privKey)
+	if err != nil {
+		return nil, err
+	}
+	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	keyPEM := pem.EncodeToMemory(&pem.Block{Type: header, Bytes: privKeyBytes})
+	return map[string][]byte{
+		corev1.TLSCertKey:       certPEM,
+		corev1.TLSPrivateKeyKey: keyPEM,
+	}, nil
+}

pkg/cert/legobridge/legobridge_suite_test.go

@@ -0,0 +1,19 @@
+/*
+ * SPDX-FileCopyrightText: 2022 SAP SE or an SAP affiliate company and Gardener contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package legobridge_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestCore(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Legobridge Suite")
+}

pkg/cert/legobridge/pki.go

@@ -33,8 +33,6 @@ var (
 )
 
 const (
-	// DefaultSigAlgo is the default Signature Algorithm (letsencrypt default).
-	DefaultSigAlgo x509.SignatureAlgorithm = x509.SHA256WithRSA
 	// DefaultPubKeyAlgo is the default Public Key Algorithm (letsencrypt default).
 	DefaultPubKeyAlgo x509.PublicKeyAlgorithm = x509.RSA
 	// DefaultCertKeyUsage is the default Key Usage (letsencrypt default).
@@ -389,10 +387,13 @@ func bytesToPrivateKey(data []byte) (crypto.PrivateKey, error) {
 	if err == nil {
 		return key, nil
 	}
-
 	key2, err2 := x509.ParsePKCS1PrivateKey(block.Bytes)
-	if err2 != nil {
-		return nil, fmt.Errorf("decoding private key failed with %s (ec) and %s (rsa)", err, err2)
+	if err2 == nil {
+		return key2, nil
+	}
+	key3, err3 := x509.ParsePKCS8PrivateKey(block.Bytes)
+	if err3 != nil {
+		return nil, fmt.Errorf("decoding private key failed with %s (ec) and %s (rsa PKCS1) and %s (PKCS8)", err, err2, err3)
 	}
-	return key2, nil
+	return key3, nil
 }