75 lines
1.7 KiB
Go
75 lines
1.7 KiB
Go
package tls
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"crypto/rand"
|
|
"crypto/tls"
|
|
"crypto/x509"
|
|
"crypto/x509/pkix"
|
|
"encoding/pem"
|
|
"math/big"
|
|
"net"
|
|
"time"
|
|
)
|
|
|
|
func Certificate(host ...string) (tls.Certificate, error) {
|
|
priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
|
|
if err != nil {
|
|
return tls.Certificate{}, err
|
|
}
|
|
|
|
notBefore := time.Now()
|
|
notAfter := notBefore.Add(time.Hour * 24 * 365)
|
|
|
|
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
|
|
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
|
|
if err != nil {
|
|
return tls.Certificate{}, err
|
|
}
|
|
|
|
template := x509.Certificate{
|
|
SerialNumber: serialNumber,
|
|
Subject: pkix.Name{
|
|
Organization: []string{"Acme Co"},
|
|
},
|
|
NotBefore: notBefore,
|
|
NotAfter: notAfter,
|
|
|
|
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
|
|
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
|
|
BasicConstraintsValid: true,
|
|
}
|
|
|
|
for _, h := range host {
|
|
if ip := net.ParseIP(h); ip != nil {
|
|
template.IPAddresses = append(template.IPAddresses, ip)
|
|
} else {
|
|
template.DNSNames = append(template.DNSNames, h)
|
|
}
|
|
}
|
|
|
|
template.IsCA = true
|
|
template.KeyUsage |= x509.KeyUsageCertSign
|
|
|
|
derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
|
|
if err != nil {
|
|
return tls.Certificate{}, err
|
|
}
|
|
|
|
// create public key
|
|
certOut := bytes.NewBuffer(nil)
|
|
pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
|
|
|
|
// create private key
|
|
keyOut := bytes.NewBuffer(nil)
|
|
b, err := x509.MarshalECPrivateKey(priv)
|
|
if err != nil {
|
|
return tls.Certificate{}, err
|
|
}
|
|
pem.Encode(keyOut, &pem.Block{Type: "EC PRIVATE KEY", Bytes: b})
|
|
|
|
return tls.X509KeyPair(certOut.Bytes(), keyOut.Bytes())
|
|
}
|