add k8s client

vendor/k8s.io/client-go/util/cert/csr.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2016 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 cert
+
+import (
+	cryptorand "crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"net"
+)
+
+// MakeCSR generates a PEM-encoded CSR using the supplied private key, subject, and SANs.
+// All key types that are implemented via crypto.Signer are supported (This includes *rsa.PrivateKey and *ecdsa.PrivateKey.)
+func MakeCSR(privateKey interface{}, subject *pkix.Name, dnsSANs []string, ipSANs []net.IP) (csr []byte, err error) {
+	template := &x509.CertificateRequest{
+		Subject:     *subject,
+		DNSNames:    dnsSANs,
+		IPAddresses: ipSANs,
+	}
+
+	return MakeCSRFromTemplate(privateKey, template)
+}
+
+// MakeCSRFromTemplate generates a PEM-encoded CSR using the supplied private
+// key and certificate request as a template. All key types that are
+// implemented via crypto.Signer are supported (This includes *rsa.PrivateKey
+// and *ecdsa.PrivateKey.)
+func MakeCSRFromTemplate(privateKey interface{}, template *x509.CertificateRequest) ([]byte, error) {
+	t := *template
+	t.SignatureAlgorithm = sigType(privateKey)
+
+	csrDER, err := x509.CreateCertificateRequest(cryptorand.Reader, &t, privateKey)
+	if err != nil {
+		return nil, err
+	}
+
+	csrPemBlock := &pem.Block{
+		Type:  CertificateRequestBlockType,
+		Bytes: csrDER,
+	}
+
+	return pem.EncodeToMemory(csrPemBlock), nil
+}
+
+func sigType(privateKey interface{}) x509.SignatureAlgorithm {
+	// Customize the signature for RSA keys, depending on the key size
+	if privateKey, ok := privateKey.(*rsa.PrivateKey); ok {
+		keySize := privateKey.N.BitLen()
+		switch {
+		case keySize >= 4096:
+			return x509.SHA512WithRSA
+		case keySize >= 3072:
+			return x509.SHA384WithRSA
+		default:
+			return x509.SHA256WithRSA
+		}
+	}
+	return x509.UnknownSignatureAlgorithm
+}