/
certs.go
268 lines (227 loc) · 7.22 KB
/
certs.go
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package utils
import (
cryptorand "crypto/rand"
"crypto/rsa"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"errors"
"fmt"
"k8s.io/apimachinery/pkg/runtime"
clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
clientcmdlatest "k8s.io/client-go/tools/clientcmd/api/latest"
"math"
"math/big"
"net"
"time"
)
const (
rsaKeySize = 2048
duration365d = time.Hour * 24 * 365
defaultExpiredTime = 100
)
const (
ECPrivateKeyBlockType = "EC PRIVATE KEY"
RSAPrivateKeyBlockType = "RSA PRIVATE KEY"
PrivateKeyBlockType = "PRIVATE KEY"
CertificateBlockType = "CERTIFICATE"
CertificateRequestBlockType = "CERTIFICATE REQUEST"
AdminKubeConfigFileName = "admin.conf"
ControllerManagerKubeConfigFileName = "controller-manager.conf"
SchedulerKubeConfigFileName = "scheduler.conf"
DefaultServerUrl = "https://127.0.0.1:6443"
)
type Config struct {
CommonName string
Organization []string
AltNames AltNames
Usages []x509.ExtKeyUsage
}
type AltNames struct {
DNSNames []string
IPs []net.IP
}
// NewSelfSignedCACert creates a CA certificate
func NewSelfSignedCACert(cfg Config, key *rsa.PrivateKey) (*x509.Certificate, error) {
now := time.Now()
tmpl := x509.Certificate{
SerialNumber: new(big.Int).SetInt64(0),
Subject: pkix.Name{
CommonName: cfg.CommonName,
Organization: cfg.Organization,
},
NotBefore: now.UTC(),
NotAfter: now.Add(duration365d * time.Duration(defaultExpiredTime)).UTC(),
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
BasicConstraintsValid: true,
IsCA: true,
}
certDERBytes, err := x509.CreateCertificate(cryptorand.Reader, &tmpl, &tmpl, key.Public(), key)
if err != nil {
return nil, err
}
return x509.ParseCertificate(certDERBytes)
}
// NewSignedCert creates a signed certificate using the given CA certificate and key
func NewSignedCert(cfg Config, key *rsa.PrivateKey, caCert *x509.Certificate, caKey *rsa.PrivateKey) (*x509.Certificate, error) {
serial, err := cryptorand.Int(cryptorand.Reader, new(big.Int).SetInt64(math.MaxInt64))
if err != nil {
return nil, err
}
if len(cfg.CommonName) == 0 {
return nil, errors.New("must specify a CommonName")
}
if len(cfg.Usages) == 0 {
return nil, errors.New("must specify at least one ExtKeyUsage")
}
certTmpl := x509.Certificate{
Subject: pkix.Name{
CommonName: cfg.CommonName,
Organization: cfg.Organization,
},
DNSNames: cfg.AltNames.DNSNames,
IPAddresses: cfg.AltNames.IPs,
SerialNumber: serial,
NotBefore: caCert.NotBefore,
NotAfter: caCert.NotAfter,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: cfg.Usages,
}
certDERBytes, err := x509.CreateCertificate(cryptorand.Reader, &certTmpl, caCert, key.Public(), caKey)
if err != nil {
return nil, err
}
return x509.ParseCertificate(certDERBytes)
}
func GenerateCaCert(cfg Config) (*x509.Certificate,*rsa.PrivateKey,error) {
key, err := NewPrivateKey()
if err != nil {
return nil, nil, err
}
caCert, err := NewSelfSignedCACert(cfg, key)
if err != nil {
return nil, nil, err
}
return caCert, key, nil
}
func GenerateCert(cfg Config, caCert *x509.Certificate, caKey *rsa.PrivateKey) (*x509.Certificate,*rsa.PrivateKey,error) {
key, err := NewPrivateKey()
if err != nil {
return nil, nil, err
}
cert, err := NewSignedCert(cfg, key, caCert, caKey)
if err != nil {
return nil, nil, err
}
return cert, key, nil
}
func GenerateServiceAccountKey() (*rsa.PrivateKey,error) {
saSigningKey, err := NewServiceAccountSigningKey()
if err != nil {
return nil, err
}
return saSigningKey, nil
}
func NewServiceAccountSigningKey() (*rsa.PrivateKey, error) {
saSigningKey, err := NewPrivateKey()
if err != nil {
return nil, fmt.Errorf("failure while creating service account token signing key: %v", err)
}
return saSigningKey, nil
}
func NewPrivateKey() (*rsa.PrivateKey, error) {
return rsa.GenerateKey(cryptorand.Reader, rsaKeySize)
}
func EncodeCertPEM(cert *x509.Certificate) []byte {
block := pem.Block{
Type: CertificateBlockType,
Bytes: cert.Raw,
}
return pem.EncodeToMemory(&block)
}
func EncodePrivateKeyPEM(key *rsa.PrivateKey) []byte {
block := pem.Block{
Type: RSAPrivateKeyBlockType,
Bytes: x509.MarshalPKCS1PrivateKey(key),
}
return pem.EncodeToMemory(&block)
}
func EncodePublicKeyPEM(key *rsa.PublicKey) ([]byte, error) {
der, err := x509.MarshalPKIXPublicKey(key)
if err != nil {
return []byte{}, err
}
block := pem.Block{
Type: "PUBLIC KEY",
Bytes: der,
}
return pem.EncodeToMemory(&block), nil
}
func CreateKubeconfigWithCerts(serverURL, clusterName, userName string, caCert []byte, clientKey []byte, clientCert []byte) *clientcmdapi.Config {
config := CreateBasic(serverURL, clusterName, userName, caCert)
config.AuthInfos[userName] = &clientcmdapi.AuthInfo{
ClientKeyData: clientKey,
ClientCertificateData: clientCert,
}
return config
}
func CreateBasic(serverURL, clusterName, userName string, caCert []byte) *clientcmdapi.Config {
// Use the cluster and the username as the context name
contextName := fmt.Sprintf("%s@%s", userName, clusterName)
return &clientcmdapi.Config{
Clusters: map[string]*clientcmdapi.Cluster{
clusterName: {
Server: serverURL,
CertificateAuthorityData: caCert,
},
},
Contexts: map[string]*clientcmdapi.Context{
contextName: {
Cluster: clusterName,
AuthInfo: userName,
},
},
AuthInfos: map[string]*clientcmdapi.AuthInfo{},
CurrentContext: contextName,
}
}
func CreateAdminKubeconfig(caCert *x509.Certificate, caKey *rsa.PrivateKey, serverUrl string) ([]byte, error) {
cfg := Config{
CommonName: "kubernetes-admin",
Organization: []string{"system:masters"},
Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
}
cert, key, err := GenerateCert(cfg, caCert, caKey)
if err != nil {
return nil, err
}
kubeconfig := CreateKubeconfigWithCerts(serverUrl, "kubernetes", "kubernetes-admin",
EncodeCertPEM(caCert), EncodePrivateKeyPEM(key), EncodeCertPEM(cert))
return runtime.Encode(clientcmdlatest.Codec, kubeconfig)
}
func CreateControllerManagerKUbeconfig(caCert *x509.Certificate, caKey *rsa.PrivateKey, serverUrl string) ([]byte, error) {
cfg := Config{
CommonName: "system:kube-controller-manager",
Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
}
cert, key, err := GenerateCert(cfg, caCert, caKey)
if err != nil {
return nil, err
}
kubeconfig := CreateKubeconfigWithCerts(serverUrl, "kubernetes", "system:kube-controller-manager",
EncodeCertPEM(caCert), EncodePrivateKeyPEM(key), EncodeCertPEM(cert))
return runtime.Encode(clientcmdlatest.Codec, kubeconfig)
}
func CreateSchedulerKubeconfig(caCert *x509.Certificate, caKey *rsa.PrivateKey, serverUrl string) ([]byte, error) {
cfg := Config{
CommonName: "system:kube-scheduler",
Usages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
}
cert, key, err := GenerateCert(cfg, caCert, caKey)
if err != nil {
return nil, err
}
kubeconfig := CreateKubeconfigWithCerts(serverUrl, "kubernetes", "system:kube-scheduler",
EncodeCertPEM(caCert), EncodePrivateKeyPEM(key), EncodeCertPEM(cert))
return runtime.Encode(clientcmdlatest.Codec, kubeconfig)
}