Two implmentations of cert renewal

cmd/kubeadm/app/phases/certs/renewal/certsapi.go

+/*
+Copyright 2018 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 renewal
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"errors"
+	"fmt"
+	"time"
+
+	certsapi "k8s.io/api/certificates/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/kubernetes"
+	certstype "k8s.io/client-go/kubernetes/typed/certificates/v1beta1"
+	certutil "k8s.io/client-go/util/cert"
+)
+
+const (
+	certAPIPrefixName = "kubeadm-cert"
+)
+
+var (
+	watchTimeout = 5 * time.Minute
+)
+
+// CertsAPIRenewal creates new certificates using the certs API
+type CertsAPIRenewal struct {
+	client certstype.CertificatesV1beta1Interface
+}
+
+// NewCertsAPIRenawal takes a certificate pair to construct the Interface.
+func NewCertsAPIRenawal(client kubernetes.Interface) Interface {
+	return &CertsAPIRenewal{
+		client: client.CertificatesV1beta1(),
+	}
+}
+
+// Renew takes a certificate using the cert and key.
+func (r *CertsAPIRenewal) Renew(cfg *certutil.Config) (*x509.Certificate, crypto.PrivateKey, error) {
+	reqTmp := &x509.CertificateRequest{
+		Subject: pkix.Name{
+			CommonName:   cfg.CommonName,
+			Organization: cfg.Organization,
+		},
+		DNSNames:    cfg.AltNames.DNSNames,
+		IPAddresses: cfg.AltNames.IPs,
+	}
+
+	key, err := certutil.NewPrivateKey()
+	if err != nil {
+		return nil, nil, fmt.Errorf("Couldn't create new private key: %v", err)
+	}
+
+	csr, err := x509.CreateCertificateRequest(rand.Reader, reqTmp, key)
+	if err != nil {
+		return nil, nil, fmt.Errorf("Couldn't create csr: %v", err)
+	}
+
+	usages := make([]certsapi.KeyUsage, len(cfg.Usages))
+	for i, usage := range cfg.Usages {
+		certsAPIUsage, ok := usageMap[usage]
+		if !ok {
+			return nil, nil, fmt.Errorf("unknown key usage %v", usage)
+		}
+		usages[i] = certsAPIUsage
+	}
+
+	k8sCSR := &certsapi.CertificateSigningRequest{
+		ObjectMeta: metav1.ObjectMeta{
+			GenerateName: certAPIPrefixName,
+		},
+		Spec: certsapi.CertificateSigningRequestSpec{
+			Request: csr,
+			Usages:  usages,
+		},
+	}
+
+	req, err := r.client.CertificateSigningRequests().Create(k8sCSR)
+	if err != nil {
+		return nil, nil, fmt.Errorf("couldn't create certificate signing request: %v", err)
+	}
+
+	watcher, err := r.client.CertificateSigningRequests().Watch(metav1.ListOptions{
+		Watch:         true,
+		FieldSelector: fields.Set{"metadata.name": req.Name}.String(),
+	})
+	if err != nil {
+		return nil, nil, fmt.Errorf("couldn't watch for certificate creation: %v", err)
+	}
+	defer watcher.Stop()
+
+	select {
+	case ev := <-watcher.ResultChan():
+		if ev.Type != watch.Modified {
+			return nil, nil, fmt.Errorf("unexpected event receieved: %q", ev.Type)
+		}
+	case <-time.After(watchTimeout):
+		return nil, nil, errors.New("timeout trying to sign certificate")
+	}
+
+	req, err = r.client.CertificateSigningRequests().Get(req.Name, metav1.GetOptions{})
+	if len(req.Status.Conditions) < 1 {
+		return nil, nil, errors.New("certificate signing request has no statuses")
+	}
+
+	// TODO: under what circumstances are there more than one?
+	if status := req.Status.Conditions[0].Type; status != certsapi.CertificateApproved {
+		return nil, nil, fmt.Errorf("Unexpected certificate status %v", status)
+	}
+
+	cert, err := x509.ParseCertificate(req.Status.Certificate)
+	if err != nil {
+		return nil, nil, fmt.Errorf("couldn't parse issued certificate: %v", err)
+	}
+
+	return cert, key, nil
+}
+
+var usageMap = map[x509.ExtKeyUsage]certsapi.KeyUsage{
+	x509.ExtKeyUsageAny:                        certsapi.UsageAny,
+	x509.ExtKeyUsageServerAuth:                 certsapi.UsageServerAuth,
+	x509.ExtKeyUsageClientAuth:                 certsapi.UsageClientAuth,
+	x509.ExtKeyUsageCodeSigning:                certsapi.UsageCodeSigning,
+	x509.ExtKeyUsageEmailProtection:            certsapi.UsageEmailProtection,
+	x509.ExtKeyUsageIPSECEndSystem:             certsapi.UsageIPsecEndSystem,
+	x509.ExtKeyUsageIPSECTunnel:                certsapi.UsageIPsecTunnel,
+	x509.ExtKeyUsageIPSECUser:                  certsapi.UsageIPsecUser,
+	x509.ExtKeyUsageTimeStamping:               certsapi.UsageTimestamping,
+	x509.ExtKeyUsageOCSPSigning:                certsapi.UsageOCSPSigning,
+	x509.ExtKeyUsageMicrosoftServerGatedCrypto: certsapi.UsageMicrosoftSGC,
+	x509.ExtKeyUsageNetscapeServerGatedCrypto:  certsapi.UsageNetscapSGC,
+}

cmd/kubeadm/app/phases/certs/renewal/filerenewal.go

+/*
+Copyright 2018 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 renewal
+
+import (
+	"crypto"
+	"crypto/rsa"
+	"crypto/x509"
+	"fmt"
+
+	certutil "k8s.io/client-go/util/cert"
+	"k8s.io/kubernetes/cmd/kubeadm/app/phases/certs/pkiutil"
+)
+
+// FileRenewal renews a certificate using local certs
+type FileRenewal struct {
+	caCert *x509.Certificate
+	caKey  crypto.PrivateKey
+}
+
+// NewFileRenewal takes a certificate pair to construct the Interface.
+func NewFileRenewal(caCert *x509.Certificate, caKey crypto.PrivateKey) Interface {
+	return &FileRenewal{
+		caCert: caCert,
+		caKey:  caKey,
+	}
+}
+
+// Renew takes a certificate using the cert and key
+func (r *FileRenewal) Renew(cfg *certutil.Config) (*x509.Certificate, crypto.PrivateKey, error) {
+	caKey, ok := r.caKey.(*rsa.PrivateKey)
+	if !ok {
+		return nil, nil, fmt.Errorf("unsupported private key type %t", r.caKey)
+	}
+
+	return pkiutil.NewCertAndKey(r.caCert, caKey, cfg)
+}

cmd/kubeadm/app/phases/certs/renewal/filerenewal_test.go

+/*
+Copyright 2018 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 renewal
+
+import (
+	"crypto/x509"
+	"testing"
+
+	certutil "k8s.io/client-go/util/cert"
+	"k8s.io/kubernetes/cmd/kubeadm/app/phases/certs"
+)
+
+func TestFileRenew(t *testing.T) {
+	caCertCfg := &certutil.Config{CommonName: "kubernetes"}
+	caCert, caKey, err := certs.NewCACertAndKey(caCertCfg)
+	if err != nil {
+		t.Fatalf("couldn't create CA: %v", err)
+	}
+
+	fr := NewFileRenewal(caCert, caKey)
+
+	certCfg := &certutil.Config{
+		CommonName: "test-certs",
+		AltNames: certutil.AltNames{
+			DNSNames: []string{"test-domain.space"},
+		},
+		Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+	}
+
+	cert, _, err := fr.Renew(certCfg)
+	if err != nil {
+		t.Fatalf("unexpected error renewing cert: %v", err)
+	}
+
+	pool := x509.NewCertPool()
+	pool.AddCert(caCert)
+
+	_, err = cert.Verify(x509.VerifyOptions{
+		DNSName:   "test-domain.space",
+		Roots:     pool,
+		KeyUsages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+	})
+	if err != nil {
+		t.Errorf("couldn't verify new cert: %v", err)
+	}
+
+}

cmd/kubeadm/app/phases/certs/renewal/interface.go

+/*
+Copyright 2018 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 renewal
+
+import (
+	"crypto"
+	"crypto/x509"
+
+	certutil "k8s.io/client-go/util/cert"
+)
+
+// Interface represents a standard way to renew a certificate.
+type Interface interface {
+	Renew(*certutil.Config) (*x509.Certificate, crypto.PrivateKey, error)
+}

cmd/kubeadm/app/phases/certs/renewal/renewal_test.go

+/*
+Copyright 2018 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 renewal
+
+import (
+	"crypto/rsa"
+	"crypto/x509"
+	"testing"
+	"time"
+
+	certsapi "k8s.io/api/certificates/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/watch"
+	fakecerts "k8s.io/client-go/kubernetes/typed/certificates/v1beta1/fake"
+	k8stesting "k8s.io/client-go/testing"
+	certutil "k8s.io/client-go/util/cert"
+	"k8s.io/kubernetes/cmd/kubeadm/app/phases/certs"
+	"k8s.io/kubernetes/cmd/kubeadm/app/phases/certs/pkiutil"
+)
+
+func TestRenewImplementations(t *testing.T) {
+	caCertCfg := &certutil.Config{CommonName: "kubernetes"}
+	caCert, caKey, err := certs.NewCACertAndKey(caCertCfg)
+	if err != nil {
+		t.Fatalf("couldn't create CA: %v", err)
+	}
+
+	client := &fakecerts.FakeCertificatesV1beta1{
+		Fake: &k8stesting.Fake{},
+	}
+	certReq := getCertReq(t, caCert, caKey)
+	client.AddReactor("get", "certificatesigningrequests", defaultReactionFunc(certReq))
+	watcher := watch.NewFakeWithChanSize(1, false)
+	watcher.Modify(certReq)
+	client.AddWatchReactor("certificatesigningrequests", k8stesting.DefaultWatchReactor(watcher, nil))
+
+	// override the timeout so tests are faster
+	watchTimeout = time.Second
+
+	tests := []struct {
+		name string
+		impl Interface
+	}{
+		{
+			name: "filerenewal",
+			impl: NewFileRenewal(caCert, caKey),
+		},
+		{
+			name: "certs api",
+			impl: &CertsAPIRenewal{
+				client: client,
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+
+			certCfg := &certutil.Config{
+				CommonName: "test-certs",
+				AltNames: certutil.AltNames{
+					DNSNames: []string{"test-domain.space"},
+				},
+				Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+			}
+
+			cert, _, err := test.impl.Renew(certCfg)
+			if err != nil {
+				t.Fatalf("unexpected error renewing cert: %v", err)
+			}
+
+			pool := x509.NewCertPool()
+			pool.AddCert(caCert)
+
+			_, err = cert.Verify(x509.VerifyOptions{
+				DNSName:   "test-domain.space",
+				Roots:     pool,
+				KeyUsages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+			})
+			if err != nil {
+				t.Errorf("couldn't verify new cert: %v", err)
+			}
+		})
+	}
+}
+
+func defaultReactionFunc(obj runtime.Object) k8stesting.ReactionFunc {
+	return func(act k8stesting.Action) (bool, runtime.Object, error) {
+		return true, obj, nil
+	}
+}
+
+func getCertReq(t *testing.T, caCert *x509.Certificate, caKey *rsa.PrivateKey) *certsapi.CertificateSigningRequest {
+	cert, _, err := pkiutil.NewCertAndKey(caCert, caKey, &certutil.Config{
+		CommonName: "testcert",
+		AltNames: certutil.AltNames{
+			DNSNames: []string{"test-domain.space"},
+		},
+		Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+	})
+	if err != nil {
+		t.Fatalf("couldn't generate cert: %v", err)
+	}
+
+	return &certsapi.CertificateSigningRequest{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "testcert",
+		},
+		Status: certsapi.CertificateSigningRequestStatus{
+			Conditions: []certsapi.CertificateSigningRequestCondition{
+				certsapi.CertificateSigningRequestCondition{
+					Type: certsapi.CertificateApproved,
+				},
+			},
+			Certificate: cert.Raw,
+		},
+	}
+}