Merge pull request #59966 from liggitt/self-signed-ca

Automatic merge from submit-queue (batch tested with PRs 59463, 59719, 60181, 58283, 59966). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Split self-signed cert and CA

The key usage limitation of TLS Server Auth makes the cert invalid as a CA.

This switches to generate a single-use CA, uses it to sign the serving cert, then appends the CA to the cert bytes.

* allows a client to continue to reference the cert file as a trust bundle, which now contains a valid CA cert
* continues to keep the generated certificate valid only for serving purposes

Fixes https://github.com/kubernetes/client-go/issues/311

```release-note
NONE
```
This commit is contained in:
Kubernetes Submit Queue 2018-02-23 00:34:34 -08:00 committed by GitHub
commit 5d144152e4
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -138,23 +138,50 @@ func MakeEllipticPrivateKeyPEM() ([]byte, error) {
// Host may be an IP or a DNS name
// You may also specify additional subject alt names (either ip or dns names) for the certificate
func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS []string) ([]byte, []byte, error) {
caKey, err := rsa.GenerateKey(cryptorand.Reader, 2048)
if err != nil {
return nil, nil, err
}
caTemplate := x509.Certificate{
SerialNumber: big.NewInt(1),
Subject: pkix.Name{
CommonName: fmt.Sprintf("%s-ca@%d", host, time.Now().Unix()),
},
NotBefore: time.Now(),
NotAfter: time.Now().Add(time.Hour * 24 * 365),
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
BasicConstraintsValid: true,
IsCA: true,
}
caDERBytes, err := x509.CreateCertificate(cryptorand.Reader, &caTemplate, &caTemplate, &caKey.PublicKey, caKey)
if err != nil {
return nil, nil, err
}
caCertificate, err := x509.ParseCertificate(caDERBytes)
if err != nil {
return nil, nil, err
}
priv, err := rsa.GenerateKey(cryptorand.Reader, 2048)
if err != nil {
return nil, nil, err
}
template := x509.Certificate{
SerialNumber: big.NewInt(1),
SerialNumber: big.NewInt(2),
Subject: pkix.Name{
CommonName: fmt.Sprintf("%s@%d", host, time.Now().Unix()),
},
NotBefore: time.Now(),
NotAfter: time.Now().Add(time.Hour * 24 * 365),
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
BasicConstraintsValid: true,
IsCA: true,
}
if ip := net.ParseIP(host); ip != nil {
@ -166,16 +193,19 @@ func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS
template.IPAddresses = append(template.IPAddresses, alternateIPs...)
template.DNSNames = append(template.DNSNames, alternateDNS...)
derBytes, err := x509.CreateCertificate(cryptorand.Reader, &template, &template, &priv.PublicKey, priv)
derBytes, err := x509.CreateCertificate(cryptorand.Reader, &template, caCertificate, &priv.PublicKey, caKey)
if err != nil {
return nil, nil, err
}
// Generate cert
// Generate cert, followed by ca
certBuffer := bytes.Buffer{}
if err := pem.Encode(&certBuffer, &pem.Block{Type: CertificateBlockType, Bytes: derBytes}); err != nil {
return nil, nil, err
}
if err := pem.Encode(&certBuffer, &pem.Block{Type: CertificateBlockType, Bytes: caDERBytes}); err != nil {
return nil, nil, err
}
// Generate key
keyBuffer := bytes.Buffer{}