th5/generate_cert.go
2012-01-04 14:56:16 -05:00

73 lines
1.8 KiB
Go

// 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 (
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"flag"
"log"
"math/big"
"os"
"time"
)
var hostName *string = flag.String("host", "127.0.0.1", "Hostname to generate a certificate for")
func main() {
flag.Parse()
priv, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
log.Fatalf("failed to generate private key: %s", err)
return
}
now := time.Now()
template := x509.Certificate{
SerialNumber: new(big.Int).SetInt64(0),
Subject: pkix.Name{
CommonName: *hostName,
Organization: []string{"Acme Co"},
},
NotBefore: now.Add(-5 * time.Minute).UTC(),
NotAfter: now.AddDate(1, 0, 0).UTC(), // 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)
return
}
certOut, err := os.Create("cert.pem")
if err != nil {
log.Fatalf("failed to open cert.pem for writing: %s", err)
return
}
pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
certOut.Close()
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)
return
}
pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
keyOut.Close()
log.Print("written key.pem\n")
}