clean up certificate processing

cmd/nginx/main.go

@@ -110,14 +110,19 @@ func main() {
 	}
 
 	// create the default SSL certificate (dummy)
+	// TODO(elvinefendi) do this in a single function in ssl package
 	defCert, defKey := ssl.GetFakeSSLCert()
-	c, err := ssl.AddOrUpdateCertAndKey(fakeCertificate, defCert, defKey, []byte{}, fs)
+	sslCert, err := ssl.CreateSSLCert(defCert, defKey)
 	if err != nil {
-		klog.Fatalf("Error generating self-signed certificate: %v", err)
+		klog.Fatalf("unexpected error creating fake SSL Cert: %v", err)
 	}
-
+	err = ssl.StoreSSLCertOnDisk(fs, fakeCertificate, sslCert)
-	conf.FakeCertificatePath = c.PemFileName
+	if err != nil {
-	conf.FakeCertificateSHA = c.PemSHA
+		klog.Fatalf("unexpected error storing fake SSL Cert: %v", err)
+	}
+	conf.FakeCertificatePath = sslCert.PemFileName
+	conf.FakeCertificateSHA = sslCert.PemSHA
+	// end create default fake SSL certificates
 
 	conf.Client = kubeClient
 

internal/ingress/controller/store/backend_ssl.go

@@ -98,17 +98,22 @@ func (s *k8sStore) getPemCertificate(secretName string) (*ingress.SSLCert, error
 			return nil, fmt.Errorf("key 'tls.key' missing from Secret %q", secretName)
 		}
 
-		if s.isDynamicCertificatesEnabled {
+		sslCert, err = ssl.CreateSSLCert(cert, key)
-			sslCert, err = ssl.CreateSSLCert(nsSecName, cert, key, ca)
+		if err != nil {
+			return nil, fmt.Errorf("unexpected error creating SSL Cert: %v", err)
+		}
+
+		if !s.isDynamicCertificatesEnabled {
+			err = ssl.StoreSSLCertOnDisk(s.filesystem, nsSecName, sslCert)
 			if err != nil {
-				return nil, fmt.Errorf("unexpected error creating SSL Cert: %v", err)
+				return nil, fmt.Errorf("error while storing certificate and key: %v", err)
 			}
-		} else {
+		}
-			// If 'ca.crt' is also present, it will allow this secret to be used in the
+
-			// 'nginx.ingress.kubernetes.io/auth-tls-secret' annotation
+		if len(ca) > 0 {
-			sslCert, err = ssl.AddOrUpdateCertAndKey(nsSecName, cert, key, ca, s.filesystem)
+			err = ssl.ConfigureCACertWithCertAndKey(s.filesystem, nsSecName, ca, sslCert)
 			if err != nil {
-				return nil, fmt.Errorf("unexpected error creating pem file: %v", err)
+				return nil, fmt.Errorf("error configuring CA certificate: %v", err)
 			}
 		}
 
@@ -118,11 +123,15 @@ func (s *k8sStore) getPemCertificate(secretName string) (*ingress.SSLCert, error
 		}
 		klog.V(3).Info(msg)
 
-	} else if ca != nil {
+	} else if ca != nil && len(ca) > 0 {
-		sslCert, err = ssl.AddCertAuth(nsSecName, ca, s.filesystem)
+		sslCert, err = ssl.CreateCACert(ca)
-
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("unexpected error creating SSL Cert: %v", err)
+		}
+
+		err = ssl.ConfigureCACert(s.filesystem, nsSecName, ca, sslCert)
+		if err != nil {
+			return nil, fmt.Errorf("error configuring CA certificate: %v", err)
 		}
 
 		// makes this secret in 'syncSecret' to be used for Certificate Authentication

internal/net/ssl/ssl.go

@@ -67,144 +67,8 @@ func verifyPemCertAgainstRootCA(pemCert *x509.Certificate, ca []byte) error {
 	return nil
 }
 
-// AddOrUpdateCertAndKey creates a .pem file with the cert and the key with the specified name
+// CreateSSLCert validates cert and key, extracts common names and returns corresponding SSLCert object
-func AddOrUpdateCertAndKey(name string, cert, key, ca []byte,
+func CreateSSLCert(cert, key []byte) (*ingress.SSLCert, error) {
-	fs file.Filesystem) (*ingress.SSLCert, error) {
-
-	pemFileName, pemName := getPemFileName(name)
-	tempPemFile, err := fs.TempFile(file.DefaultSSLDirectory, pemName)
-
-	if err != nil {
-		return nil, fmt.Errorf("could not create temp pem file %v: %v", pemFileName, err)
-	}
-	klog.V(3).Infof("Creating temp file %v for Keypair: %v", tempPemFile.Name(), pemName)
-
-	_, err = tempPemFile.Write(cert)
-	if err != nil {
-		return nil, fmt.Errorf("could not write to pem file %v: %v", tempPemFile.Name(), err)
-	}
-	_, err = tempPemFile.Write([]byte("\n"))
-	if err != nil {
-		return nil, fmt.Errorf("could not write to pem file %v: %v", tempPemFile.Name(), err)
-	}
-	_, err = tempPemFile.Write(key)
-	if err != nil {
-		return nil, fmt.Errorf("could not write to pem file %v: %v", tempPemFile.Name(), err)
-	}
-
-	err = tempPemFile.Close()
-	if err != nil {
-		return nil, fmt.Errorf("could not close temp pem file %v: %v", tempPemFile.Name(), err)
-	}
-	defer fs.RemoveAll(tempPemFile.Name())
-
-	pemCerts, err := fs.ReadFile(tempPemFile.Name())
-	if err != nil {
-		return nil, err
-	}
-
-	pemBlock, _ := pem.Decode(pemCerts)
-	if pemBlock == nil {
-		return nil, fmt.Errorf("no valid PEM formatted block found")
-	}
-
-	// If the file does not start with 'BEGIN CERTIFICATE' it's invalid and must not be used.
-	if pemBlock.Type != "CERTIFICATE" {
-		return nil, fmt.Errorf("certificate %v contains invalid data, and must be created with 'kubectl create secret tls'", name)
-	}
-
-	pemCert, err := x509.ParseCertificate(pemBlock.Bytes)
-	if err != nil {
-		return nil, err
-	}
-
-	//Ensure that certificate and private key have a matching public key
-	if _, err := tls.X509KeyPair(cert, key); err != nil {
-		return nil, err
-	}
-
-	cn := sets.NewString(pemCert.Subject.CommonName)
-	for _, dns := range pemCert.DNSNames {
-		if !cn.Has(dns) {
-			cn.Insert(dns)
-		}
-	}
-
-	if len(pemCert.Extensions) > 0 {
-		klog.V(3).Info("parsing ssl certificate extensions")
-		for _, ext := range getExtension(pemCert, oidExtensionSubjectAltName) {
-			dns, _, _, err := parseSANExtension(ext.Value)
-			if err != nil {
-				klog.Warningf("unexpected error parsing certificate extensions: %v", err)
-				continue
-			}
-
-			for _, dns := range dns {
-				if !cn.Has(dns) {
-					cn.Insert(dns)
-				}
-			}
-		}
-	}
-
-	err = fs.Rename(tempPemFile.Name(), pemFileName)
-	if err != nil {
-		return nil, fmt.Errorf("could not move temp pem file %v to destination %v: %v", tempPemFile.Name(), pemFileName, err)
-	}
-
-	if len(ca) > 0 {
-		err := verifyPemCertAgainstRootCA(pemCert, ca)
-		if err != nil {
-			oe := fmt.Sprintf("failed to verify certificate chain: \n\t%s\n", err)
-			return nil, errors.New(oe)
-		}
-
-		caData, err := fs.ReadFile(pemFileName)
-		if err != nil {
-			return nil, fmt.Errorf("could not open file %v for writing additional CA chains: %v", pemFileName, err)
-		}
-
-		caFile, err := fs.Create(pemFileName)
-		if err != nil {
-			return nil, fmt.Errorf("could not create CA cert file %v: %v", pemFileName, err)
-		}
-
-		_, err = caFile.Write(caData)
-		if err != nil {
-			return nil, fmt.Errorf("could not append CA to cert file %v: %v", pemFileName, err)
-		}
-
-		_, err = caFile.Write([]byte("\n"))
-		if err != nil {
-			return nil, fmt.Errorf("could not append CA to cert file %v: %v", pemFileName, err)
-		}
-		caFile.Write(ca)
-		caFile.Write([]byte("\n"))
-		defer caFile.Close()
-
-		return &ingress.SSLCert{
-			Certificate: pemCert,
-			CAFileName:  pemFileName,
-			PemFileName: pemFileName,
-			PemSHA:      file.SHA1(pemFileName),
-			CN:          cn.List(),
-			ExpireTime:  pemCert.NotAfter,
-		}, nil
-	}
-
-	s := &ingress.SSLCert{
-		Certificate: pemCert,
-		PemFileName: pemFileName,
-		PemSHA:      file.SHA1(pemFileName),
-		CN:          cn.List(),
-		ExpireTime:  pemCert.NotAfter,
-	}
-
-	return s, nil
-}
-
-// CreateSSLCert creates an SSLCert and avoids writing on disk
-func CreateSSLCert(name string, cert, key, ca []byte) (*ingress.SSLCert, error) {
 	var pemCertBuffer bytes.Buffer
 
 	pemCertBuffer.Write(cert)
@@ -216,9 +80,8 @@ func CreateSSLCert(name string, cert, key, ca []byte) (*ingress.SSLCert, error)
 		return nil, fmt.Errorf("no valid PEM formatted block found")
 	}
 
-	// If the file does not start with 'BEGIN CERTIFICATE' it's invalid and must not be used.
 	if pemBlock.Type != "CERTIFICATE" {
-		return nil, fmt.Errorf("certificate %v contains invalid data, and must be created with 'kubectl create secret tls'", name)
+		return nil, fmt.Errorf("no certificate PEM data found, make sure certificate content starts with 'BEGIN CERTIFICATE'")
 	}
 
 	pemCert, err := x509.ParseCertificate(pemBlock.Bytes)
@@ -226,9 +89,8 @@ func CreateSSLCert(name string, cert, key, ca []byte) (*ingress.SSLCert, error)
 		return nil, err
 	}
 
-	//Ensure that certificate and private key have a matching public key
 	if _, err := tls.X509KeyPair(cert, key); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("certificate and private key does not have a matching public key: %v", err)
 	}
 
 	cn := sets.NewString(pemCert.Subject.CommonName)
@@ -255,26 +117,128 @@ func CreateSSLCert(name string, cert, key, ca []byte) (*ingress.SSLCert, error)
 		}
 	}
 
-	if len(ca) > 0 {
+	return &ingress.SSLCert{
-		err := verifyPemCertAgainstRootCA(pemCert, ca)
-		if err != nil {
-			oe := fmt.Sprintf("failed to verify certificate chain: \n\t%s\n", err)
-			return nil, errors.New(oe)
-		}
-
-		pemCertBuffer.Write([]byte("\n"))
-		pemCertBuffer.Write(ca)
-		pemCertBuffer.Write([]byte("\n"))
-	}
-
-	s := &ingress.SSLCert{
 		Certificate: pemCert,
 		CN:          cn.List(),
 		ExpireTime:  pemCert.NotAfter,
 		PemCertKey:  pemCertBuffer.String(),
+	}, nil
+}
+
+// CreateCACert is similar to CreateSSLCert but it creates instance of SSLCert only based on given ca after
+// parsing and validating it
+func CreateCACert(ca []byte) (*ingress.SSLCert, error) {
+	pemCABlock, _ := pem.Decode(ca)
+	if pemCABlock == nil {
+		return nil, fmt.Errorf("no valid PEM formatted block found")
+	}
+	// If the first certificate does not start with 'BEGIN CERTIFICATE' it's invalid and must not be used.
+	if pemCABlock.Type != "CERTIFICATE" {
+		return nil, fmt.Errorf("no certificate PEM data found, make sure certificate content starts with 'BEGIN CERTIFICATE'")
 	}
 
-	return s, nil
+	pemCert, err := x509.ParseCertificate(pemCABlock.Bytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ingress.SSLCert{
+		Certificate: pemCert,
+	}, nil
+}
+
+// StoreSSLCert creates a .pem file with content PemCertKey from the given sslCert
+// and sets relevant remaining fields of sslCert object
+func StoreSSLCertOnDisk(fs file.Filesystem, name string, sslCert *ingress.SSLCert) error {
+	pemFileName, _ := getPemFileName(name)
+
+	pemFile, err := fs.Create(pemFileName)
+	if err != nil {
+		return fmt.Errorf("could not create PEM certificate file %v: %v", pemFileName, err)
+	}
+	defer pemFile.Close()
+
+	_, err = pemFile.Write([]byte(sslCert.PemCertKey))
+	if err != nil {
+		return fmt.Errorf("could not write data to PEM file %v: %v", pemFileName, err)
+	}
+
+	sslCert.PemFileName = pemFileName
+	sslCert.PemSHA = file.SHA1(pemFileName)
+
+	return nil
+}
+
+func isSSLCertStoredOnDisk(sslCert *ingress.SSLCert) bool {
+	return len(sslCert.PemFileName) > 0
+}
+
+// ConfigureCACertWithCertAndKey appends ca into existing PEM file consisting of cert and key
+// and sets relevant fields in sslCert object
+func ConfigureCACertWithCertAndKey(fs file.Filesystem, name string, ca []byte, sslCert *ingress.SSLCert) error {
+	err := verifyPemCertAgainstRootCA(sslCert.Certificate, ca)
+	if err != nil {
+		oe := fmt.Sprintf("failed to verify certificate chain: \n\t%s\n", err)
+		return errors.New(oe)
+	}
+
+	certAndKey, err := fs.ReadFile(sslCert.PemFileName)
+	if err != nil {
+		return fmt.Errorf("could not read file %v for writing additional CA chains: %v", sslCert.PemFileName, err)
+	}
+
+	f, err := fs.Create(sslCert.PemFileName)
+	if err != nil {
+		return fmt.Errorf("could not create PEM file %v: %v", sslCert.PemFileName, err)
+	}
+	defer f.Close()
+
+	_, err = f.Write(certAndKey)
+	if err != nil {
+		return fmt.Errorf("could not write cert and key bundle to cert file %v: %v", sslCert.PemFileName, err)
+	}
+
+	_, err = f.Write([]byte("\n"))
+	if err != nil {
+		return fmt.Errorf("could not append newline to cert file %v: %v", sslCert.PemFileName, err)
+	}
+
+	_, err = f.Write(ca)
+	if err != nil {
+		return fmt.Errorf("could not write ca data to cert file %v: %v", sslCert.PemFileName, err)
+	}
+
+	sslCert.CAFileName = sslCert.PemFileName
+	// since we updated sslCert.PemFileName we need to recalculate the checksum
+	sslCert.PemSHA = file.SHA1(sslCert.PemFileName)
+
+	return nil
+}
+
+// ConfigureCACert is similar to ConfigureCACertWithCertAndKey but it creates a separate file
+// for CA cert and writes only ca into it and then sets relevant fields in sslCert
+func ConfigureCACert(fs file.Filesystem, name string, ca []byte, sslCert *ingress.SSLCert) error {
+	caName := fmt.Sprintf("ca-%v.pem", name)
+	fileName := fmt.Sprintf("%v/%v", file.DefaultSSLDirectory, caName)
+
+	f, err := fs.Create(fileName)
+	if err != nil {
+		return fmt.Errorf("could not write CA file %v: %v", fileName, err)
+	}
+	defer f.Close()
+
+	_, err = f.Write(ca)
+	if err != nil {
+		return fmt.Errorf("could not write CA file %v: %v", fileName, err)
+	}
+
+	sslCert.PemFileName = fileName
+	sslCert.CAFileName = fileName
+	sslCert.PemSHA = file.SHA1(fileName)
+
+	klog.V(3).Infof("Created CA Certificate for Authentication: %v", fileName)
+
+	return nil
 }
 
 func getExtension(c *x509.Certificate, id asn1.ObjectIdentifier) []pkix.Extension {
@@ -343,47 +307,6 @@ func parseSANExtension(value []byte) (dnsNames, emailAddresses []string, ipAddre
 	return
 }
 
-// AddCertAuth creates a .pem file with the specified CAs to be used in Cert Authentication
-// If it's already exists, it's clobbered.
-func AddCertAuth(name string, ca []byte, fs file.Filesystem) (*ingress.SSLCert, error) {
-
-	caName := fmt.Sprintf("ca-%v.pem", name)
-	caFileName := fmt.Sprintf("%v/%v", file.DefaultSSLDirectory, caName)
-
-	pemCABlock, _ := pem.Decode(ca)
-	if pemCABlock == nil {
-		return nil, fmt.Errorf("no valid PEM formatted block found")
-	}
-	// If the first certificate does not start with 'BEGIN CERTIFICATE' it's invalid and must not be used.
-	if pemCABlock.Type != "CERTIFICATE" {
-		return nil, fmt.Errorf("CA file %v contains invalid data, and must be created only with PEM formatted certificates", name)
-	}
-
-	pemCert, err := x509.ParseCertificate(pemCABlock.Bytes)
-	if err != nil {
-		return nil, err
-	}
-
-	caFile, err := fs.Create(caFileName)
-	if err != nil {
-		return nil, fmt.Errorf("could not write CA file %v: %v", caFileName, err)
-	}
-	defer caFile.Close()
-
-	_, err = caFile.Write(ca)
-	if err != nil {
-		return nil, fmt.Errorf("could not write CA file %v: %v", caFileName, err)
-	}
-
-	klog.V(3).Infof("Created CA Certificate for Authentication: %v", caFileName)
-	return &ingress.SSLCert{
-		Certificate: pemCert,
-		CAFileName:  caFileName,
-		PemFileName: caFileName,
-		PemSHA:      file.SHA1(caFileName),
-	}, nil
-}
-
 // AddOrUpdateDHParam creates a dh parameters file with the specified name
 func AddOrUpdateDHParam(name string, dh []byte, fs file.Filesystem) (string, error) {
 	pemFileName, pemName := getPemFileName(name)