portainer/pkg/libcrypto/ssl.go

83 lines
1.9 KiB
Go

package libcrypto
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/x509"
"encoding/pem"
"errors"
"math/big"
"net"
"os"
"time"
)
// GenerateCertsForHost generates a self-signed certificate for host and saves them at certPath and keyPath
func GenerateCertsForHost(hostname, ip, certPath, keyPath string, expiry time.Time) error {
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
if err != nil {
return err
}
template := x509.Certificate{
SerialNumber: serialNumber,
NotAfter: expiry,
NotBefore: time.Now(),
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
BasicConstraintsValid: true,
}
parsedIP := net.ParseIP(ip)
if parsedIP == nil {
return errors.New("Failed parsing host ip")
}
template.DNSNames = append(template.DNSNames, hostname)
template.IPAddresses = append(template.IPAddresses, parsedIP)
keyPair, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
return err
}
encodedCert, err := x509.CreateCertificate(rand.Reader, &template, &template, &keyPair.PublicKey, keyPair)
if err != nil {
return err
}
err = createPEMEncodedFile(certPath, "CERTIFICATE", encodedCert)
if err != nil {
return err
}
key, err := x509.MarshalECPrivateKey(keyPair)
if err != nil {
return err
}
err = createPEMEncodedFile(keyPath, "EC PRIVATE KEY", key)
if err != nil {
return err
}
return nil
}
func createPEMEncodedFile(path, header string, data []byte) error {
file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return err
}
defer file.Close()
err = pem.Encode(file, &pem.Block{Type: header, Bytes: data})
if err != nil {
return err
}
return nil
}