th5/generate_cert.go
2010-07-02 13:00:18 -04:00

80 lines
2.0 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/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
"log"
"os"
"time"
)
func main() {
if len(os.Args) != 2 {
fmt.Printf("Usage: %s <hostname of server>\n", os.Args[0])
return
}
hostName := os.Args[1]
urandom, err := os.Open("/dev/urandom", os.O_RDONLY, 0)
if err != nil {
log.Crashf("failed to open /dev/urandom: %s\n", err)
return
}
log.Stdoutf("Generating RSA key\n")
priv, err := rsa.GenerateKey(urandom, 1024)
if err != nil {
log.Crashf("failed to generate private key: %s\n", err)
return
}
now := time.Seconds()
template := x509.Certificate{
SerialNumber: []byte{0},
Subject: x509.Name{
CommonName: hostName,
Organization: "Acme Co",
},
NotBefore: time.SecondsToUTC(now - 300),
NotAfter: time.SecondsToUTC(now + 86400*365), // valid for 1 year.
SubjectKeyId: []byte{1, 2, 3, 4},
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
}
derBytes, err := x509.CreateCertificate(urandom, &template, &template, &priv.PublicKey, priv)
if err != nil {
log.Crashf("Failed to create certificate: %s", err)
return
}
certOut, err := os.Open("cert.pem", os.O_WRONLY|os.O_CREAT, 0644)
if err != nil {
log.Crashf("failed to open cert.pem for writing: %s\n", err)
return
}
pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
certOut.Close()
log.Stdoutf("written cert.pem\n")
keyOut, err := os.Open("key.pem", os.O_WRONLY|os.O_CREAT, 0600)
if err != nil {
log.Crashf("failed to open key.pem for writing: %s\n", err)
return
}
pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
keyOut.Close()
log.Stdoutf("written key.pem\n")
}