172 lines
4.8 KiB
Go
172 lines
4.8 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.
|
|
|
|
//go:build ignore
|
|
|
|
// 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/ecdsa"
|
|
"crypto/ed25519"
|
|
"crypto/elliptic"
|
|
"crypto/rand"
|
|
"crypto/rsa"
|
|
"crypto/x509"
|
|
"crypto/x509/pkix"
|
|
"encoding/pem"
|
|
"flag"
|
|
"log"
|
|
"math/big"
|
|
"net"
|
|
"os"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
var (
|
|
host = flag.String("host", "", "Comma-separated hostnames and IPs to generate a certificate for")
|
|
validFrom = flag.String("start-date", "", "Creation date formatted as Jan 1 15:04:05 2011")
|
|
validFor = flag.Duration("duration", 365*24*time.Hour, "Duration that certificate is valid for")
|
|
isCA = flag.Bool("ca", false, "whether this cert should be its own Certificate Authority")
|
|
rsaBits = flag.Int("rsa-bits", 2048, "Size of RSA key to generate. Ignored if --ecdsa-curve is set")
|
|
ecdsaCurve = flag.String("ecdsa-curve", "", "ECDSA curve to use to generate a key. Valid values are P224, P256 (recommended), P384, P521")
|
|
ed25519Key = flag.Bool("ed25519", false, "Generate an Ed25519 key")
|
|
)
|
|
|
|
func publicKey(priv any) any {
|
|
switch k := priv.(type) {
|
|
case *rsa.PrivateKey:
|
|
return &k.PublicKey
|
|
case *ecdsa.PrivateKey:
|
|
return &k.PublicKey
|
|
case ed25519.PrivateKey:
|
|
return k.Public().(ed25519.PublicKey)
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
flag.Parse()
|
|
|
|
if len(*host) == 0 {
|
|
log.Fatalf("Missing required --host parameter")
|
|
}
|
|
|
|
var priv any
|
|
var err error
|
|
switch *ecdsaCurve {
|
|
case "":
|
|
if *ed25519Key {
|
|
_, priv, err = ed25519.GenerateKey(rand.Reader)
|
|
} else {
|
|
priv, err = rsa.GenerateKey(rand.Reader, *rsaBits)
|
|
}
|
|
case "P224":
|
|
priv, err = ecdsa.GenerateKey(elliptic.P224(), rand.Reader)
|
|
case "P256":
|
|
priv, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
|
|
case "P384":
|
|
priv, err = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
|
|
case "P521":
|
|
priv, err = ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
|
|
default:
|
|
log.Fatalf("Unrecognized elliptic curve: %q", *ecdsaCurve)
|
|
}
|
|
if err != nil {
|
|
log.Fatalf("Failed to generate private key: %v", err)
|
|
}
|
|
|
|
// ECDSA, ED25519 and RSA subject keys should have the DigitalSignature
|
|
// KeyUsage bits set in the x509.Certificate template
|
|
keyUsage := x509.KeyUsageDigitalSignature
|
|
// Only RSA subject keys should have the KeyEncipherment KeyUsage bits set. In
|
|
// the context of TLS this KeyUsage is particular to RSA key exchange and
|
|
// authentication.
|
|
if _, isRSA := priv.(*rsa.PrivateKey); isRSA {
|
|
keyUsage |= x509.KeyUsageKeyEncipherment
|
|
}
|
|
|
|
var notBefore time.Time
|
|
if len(*validFrom) == 0 {
|
|
notBefore = time.Now()
|
|
} else {
|
|
notBefore, err = time.Parse("Jan 2 15:04:05 2006", *validFrom)
|
|
if err != nil {
|
|
log.Fatalf("Failed to parse creation date: %v", err)
|
|
}
|
|
}
|
|
|
|
notAfter := notBefore.Add(*validFor)
|
|
|
|
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
|
|
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
|
|
if err != nil {
|
|
log.Fatalf("Failed to generate serial number: %v", err)
|
|
}
|
|
|
|
template := x509.Certificate{
|
|
SerialNumber: serialNumber,
|
|
Subject: pkix.Name{
|
|
Organization: []string{"Acme Co"},
|
|
},
|
|
NotBefore: notBefore,
|
|
NotAfter: notAfter,
|
|
|
|
KeyUsage: keyUsage,
|
|
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
|
|
BasicConstraintsValid: true,
|
|
}
|
|
|
|
hosts := strings.Split(*host, ",")
|
|
for _, h := range hosts {
|
|
if ip := net.ParseIP(h); ip != nil {
|
|
template.IPAddresses = append(template.IPAddresses, ip)
|
|
} else {
|
|
template.DNSNames = append(template.DNSNames, h)
|
|
}
|
|
}
|
|
|
|
if *isCA {
|
|
template.IsCA = true
|
|
template.KeyUsage |= x509.KeyUsageCertSign
|
|
}
|
|
|
|
derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(priv), priv)
|
|
if err != nil {
|
|
log.Fatalf("Failed to create certificate: %v", err)
|
|
}
|
|
|
|
certOut, err := os.Create("cert.pem")
|
|
if err != nil {
|
|
log.Fatalf("Failed to open cert.pem for writing: %v", err)
|
|
}
|
|
if err := pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
|
|
log.Fatalf("Failed to write data to cert.pem: %v", err)
|
|
}
|
|
if err := certOut.Close(); err != nil {
|
|
log.Fatalf("Error closing cert.pem: %v", err)
|
|
}
|
|
log.Print("wrote cert.pem\n")
|
|
|
|
keyOut, err := os.OpenFile("key.pem", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
|
|
if err != nil {
|
|
log.Fatalf("Failed to open key.pem for writing: %v", err)
|
|
return
|
|
}
|
|
privBytes, err := x509.MarshalPKCS8PrivateKey(priv)
|
|
if err != nil {
|
|
log.Fatalf("Unable to marshal private key: %v", err)
|
|
}
|
|
if err := pem.Encode(keyOut, &pem.Block{Type: "PRIVATE KEY", Bytes: privBytes}); err != nil {
|
|
log.Fatalf("Failed to write data to key.pem: %v", err)
|
|
}
|
|
if err := keyOut.Close(); err != nil {
|
|
log.Fatalf("Error closing key.pem: %v", err)
|
|
}
|
|
log.Print("wrote key.pem\n")
|
|
}
|