76 lines
2.2 KiB
Go
76 lines
2.2 KiB
Go
|
/*
|
||
|
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
|
||
|
}
|