blob: f461888799dd42432a26df39a8830beaa3bdb42f [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Generate a self-signed X.509 certificate for a TLS server. Outputs to
// 'cert.pem' and 'key.pem' and will overwrite existing files.
package main
import (
var hostName *string = flag.String("host", "", "Hostname to generate a certificate for")
func main() {
priv, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
log.Fatalf("failed to generate private key: %s", err)
now := time.Seconds()
template := x509.Certificate{
SerialNumber: []byte{0},
Subject: x509.Name{
CommonName: *hostName,
Organization: []string{"Acme Co"},
NotBefore: time.SecondsToUTC(now - 300),
NotAfter: time.SecondsToUTC(now + 60*60*24*365), // valid for 1 year.
SubjectKeyId: []byte{1, 2, 3, 4},
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
if err != nil {
log.Fatalf("Failed to create certificate: %s", err)
certOut, err := os.Create("cert.pem")
if err != nil {
log.Fatalf("failed to open cert.pem for writing: %s", err)
pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
log.Print("written cert.pem\n")
keyOut, err := os.OpenFile("key.pem", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
log.Print("failed to open key.pem for writing:", err)
pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
log.Print("written key.pem\n")