mkcert/cert.go
2022-04-26 11:51:39 -04:00

369 lines
11 KiB
Go
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

// Copyright 2018 The mkcert Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/sha1"
"crypto/x509"
"crypto/x509/pkix"
"encoding/asn1"
"encoding/pem"
"io/ioutil"
"log"
"math/big"
"net"
"net/mail"
"net/url"
"os"
"os/user"
"path/filepath"
"regexp"
"strconv"
"strings"
"time"
pkcs12 "software.sslmate.com/src/go-pkcs12"
)
var userAndHostname string
func init() {
u, err := user.Current()
if err == nil {
userAndHostname = u.Username + "@"
}
if h, err := os.Hostname(); err == nil {
userAndHostname += h
}
if err == nil && u.Name != "" && u.Name != u.Username {
userAndHostname += " (" + u.Name + ")"
}
}
func (m *mkcert) makeCert(hosts []string) {
if m.caKey == nil {
log.Fatalln("ERROR: can't create new certificates because the CA key (rootCA-key.pem) is missing")
}
priv, err := m.generateKey(false)
fatalIfErr(err, "failed to generate certificate key")
pub := priv.(crypto.Signer).Public()
// Certificates last for 2 years and 3 months, which is always less than
// 825 days, the limit that macOS/iOS apply to all certificates,
// including custom roots. See https://support.apple.com/en-us/HT210176.
expiration := time.Now().AddDate(2, 3, 0)
tpl := &x509.Certificate{
SerialNumber: randomSerialNumber(),
Subject: pkix.Name{
Organization: []string{"mkcert development certificate"},
OrganizationalUnit: []string{userAndHostname},
},
NotBefore: time.Now(), NotAfter: expiration,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
}
for _, h := range hosts {
if ip := net.ParseIP(h); ip != nil {
tpl.IPAddresses = append(tpl.IPAddresses, ip)
} else if email, err := mail.ParseAddress(h); err == nil && email.Address == h {
tpl.EmailAddresses = append(tpl.EmailAddresses, h)
} else if uriName, err := url.Parse(h); err == nil && uriName.Scheme != "" && uriName.Host != "" {
tpl.URIs = append(tpl.URIs, uriName)
} else {
tpl.DNSNames = append(tpl.DNSNames, h)
}
}
if m.client {
tpl.ExtKeyUsage = append(tpl.ExtKeyUsage, x509.ExtKeyUsageClientAuth)
}
if len(tpl.IPAddresses) > 0 || len(tpl.DNSNames) > 0 || len(tpl.URIs) > 0 {
tpl.ExtKeyUsage = append(tpl.ExtKeyUsage, x509.ExtKeyUsageServerAuth)
}
if len(tpl.EmailAddresses) > 0 {
tpl.ExtKeyUsage = append(tpl.ExtKeyUsage, x509.ExtKeyUsageEmailProtection)
}
// IIS (the main target of PKCS #12 files), only shows the deprecated
// Common Name in the UI. See issue #115.
if m.pkcs12 {
tpl.Subject.CommonName = hosts[0]
}
cert, err := x509.CreateCertificate(rand.Reader, tpl, m.caCert, pub, m.caKey)
fatalIfErr(err, "failed to generate certificate")
certFile, keyFile, p12File := m.fileNames(hosts)
if !m.pkcs12 {
certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: cert})
privDER, err := x509.MarshalPKCS8PrivateKey(priv)
fatalIfErr(err, "failed to encode certificate key")
privPEM := pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: privDER})
if certFile == keyFile {
err = ioutil.WriteFile(keyFile, append(certPEM, privPEM...), 0600)
fatalIfErr(err, "failed to save certificate and key")
} else {
err = ioutil.WriteFile(certFile, certPEM, 0644)
fatalIfErr(err, "failed to save certificate")
err = ioutil.WriteFile(keyFile, privPEM, 0600)
fatalIfErr(err, "failed to save certificate key")
}
} else {
domainCert, _ := x509.ParseCertificate(cert)
pfxData, err := pkcs12.Encode(rand.Reader, priv, domainCert, []*x509.Certificate{m.caCert}, "changeit")
fatalIfErr(err, "failed to generate PKCS#12")
err = ioutil.WriteFile(p12File, pfxData, 0644)
fatalIfErr(err, "failed to save PKCS#12")
}
m.printHosts(hosts)
if !m.pkcs12 {
if certFile == keyFile {
log.Printf("\nThe certificate and key are at \"%s\" ✅\n\n", certFile)
} else {
log.Printf("\nThe certificate is at \"%s\" and the key at \"%s\" ✅\n\n", certFile, keyFile)
}
} else {
log.Printf("\nThe PKCS#12 bundle is at \"%s\" ✅\n", p12File)
log.Printf("\nThe legacy PKCS#12 encryption password is the often hardcoded default \"changeit\" \n\n")
}
log.Printf("It will expire on %s 🗓\n\n", expiration.Format("2 January 2006"))
}
func (m *mkcert) printHosts(hosts []string) {
secondLvlWildcardRegexp := regexp.MustCompile(`(?i)^\*\.[0-9a-z_-]+$`)
log.Printf("\nCreated a new certificate valid for the following names 📜")
for _, h := range hosts {
log.Printf(" - %q", h)
if secondLvlWildcardRegexp.MatchString(h) {
log.Printf(" Warning: many browsers don't support second-level wildcards like %q ⚠️", h)
}
}
for _, h := range hosts {
if strings.HasPrefix(h, "*.") {
log.Printf("\nReminder: X.509 wildcards only go one level deep, so this won't match a.b.%s ", h[2:])
break
}
}
}
func (m *mkcert) generateKey(rootCA bool) (crypto.PrivateKey, error) {
if m.ecdsa {
return ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
}
if rootCA {
return rsa.GenerateKey(rand.Reader, 3072)
}
return rsa.GenerateKey(rand.Reader, 2048)
}
func (m *mkcert) fileNames(hosts []string) (certFile, keyFile, p12File string) {
defaultName := strings.Replace(hosts[0], ":", "_", -1)
defaultName = strings.Replace(defaultName, "*", "_wildcard", -1)
if len(hosts) > 1 {
defaultName += "+" + strconv.Itoa(len(hosts)-1)
}
if m.client {
defaultName += "-client"
}
certFile = "./" + defaultName + ".pem"
if m.certFile != "" {
certFile = m.certFile
}
keyFile = "./" + defaultName + "-key.pem"
if m.keyFile != "" {
keyFile = m.keyFile
}
p12File = "./" + defaultName + ".p12"
if m.p12File != "" {
p12File = m.p12File
}
return
}
func randomSerialNumber() *big.Int {
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
fatalIfErr(err, "failed to generate serial number")
return serialNumber
}
func (m *mkcert) makeCertFromCSR() {
if m.caKey == nil {
log.Fatalln("ERROR: can't create new certificates because the CA key (rootCA-key.pem) is missing")
}
csrPEMBytes, err := ioutil.ReadFile(m.csrPath)
fatalIfErr(err, "failed to read the CSR")
csrPEM, _ := pem.Decode(csrPEMBytes)
if csrPEM == nil {
log.Fatalln("ERROR: failed to read the CSR: unexpected content")
}
if csrPEM.Type != "CERTIFICATE REQUEST" &&
csrPEM.Type != "NEW CERTIFICATE REQUEST" {
log.Fatalln("ERROR: failed to read the CSR: expected CERTIFICATE REQUEST, got " + csrPEM.Type)
}
csr, err := x509.ParseCertificateRequest(csrPEM.Bytes)
fatalIfErr(err, "failed to parse the CSR")
fatalIfErr(csr.CheckSignature(), "invalid CSR signature")
expiration := time.Now().AddDate(2, 3, 0)
tpl := &x509.Certificate{
SerialNumber: randomSerialNumber(),
Subject: csr.Subject,
ExtraExtensions: csr.Extensions, // includes requested SANs, KUs and EKUs
NotBefore: time.Now(), NotAfter: expiration,
// If the CSR does not request a SAN extension, fix it up for them as
// the Common Name field does not work in modern browsers. Otherwise,
// this will get overridden.
DNSNames: []string{csr.Subject.CommonName},
// Likewise, if the CSR does not set KUs and EKUs, fix it up as Apple
// platforms require serverAuth for TLS.
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
}
if m.client {
tpl.ExtKeyUsage = append(tpl.ExtKeyUsage, x509.ExtKeyUsageClientAuth)
}
if len(csr.EmailAddresses) > 0 {
tpl.ExtKeyUsage = append(tpl.ExtKeyUsage, x509.ExtKeyUsageEmailProtection)
}
cert, err := x509.CreateCertificate(rand.Reader, tpl, m.caCert, csr.PublicKey, m.caKey)
fatalIfErr(err, "failed to generate certificate")
c, err := x509.ParseCertificate(cert)
fatalIfErr(err, "failed to parse generated certificate")
var hosts []string
hosts = append(hosts, c.DNSNames...)
hosts = append(hosts, c.EmailAddresses...)
for _, ip := range c.IPAddresses {
hosts = append(hosts, ip.String())
}
for _, uri := range c.URIs {
hosts = append(hosts, uri.String())
}
certFile, _, _ := m.fileNames(hosts)
err = ioutil.WriteFile(certFile, pem.EncodeToMemory(
&pem.Block{Type: "CERTIFICATE", Bytes: cert}), 0644)
fatalIfErr(err, "failed to save certificate")
m.printHosts(hosts)
log.Printf("\nThe certificate is at \"%s\" ✅\n\n", certFile)
log.Printf("It will expire on %s 🗓\n\n", expiration.Format("2 January 2006"))
}
// loadCA will load or create the CA at CAROOT.
func (m *mkcert) loadCA() {
if !pathExists(filepath.Join(m.CAROOT, rootName)) {
m.newCA()
}
certPEMBlock, err := ioutil.ReadFile(filepath.Join(m.CAROOT, rootName))
fatalIfErr(err, "failed to read the CA certificate")
certDERBlock, _ := pem.Decode(certPEMBlock)
if certDERBlock == nil || certDERBlock.Type != "CERTIFICATE" {
log.Fatalln("ERROR: failed to read the CA certificate: unexpected content")
}
m.caCert, err = x509.ParseCertificate(certDERBlock.Bytes)
fatalIfErr(err, "failed to parse the CA certificate")
if !pathExists(filepath.Join(m.CAROOT, rootKeyName)) {
return // keyless mode, where only -install works
}
keyPEMBlock, err := ioutil.ReadFile(filepath.Join(m.CAROOT, rootKeyName))
fatalIfErr(err, "failed to read the CA key")
keyDERBlock, _ := pem.Decode(keyPEMBlock)
if keyDERBlock == nil || keyDERBlock.Type != "PRIVATE KEY" {
log.Fatalln("ERROR: failed to read the CA key: unexpected content")
}
m.caKey, err = x509.ParsePKCS8PrivateKey(keyDERBlock.Bytes)
fatalIfErr(err, "failed to parse the CA key")
}
func (m *mkcert) newCA() {
priv, err := m.generateKey(true)
fatalIfErr(err, "failed to generate the CA key")
pub := priv.(crypto.Signer).Public()
spkiASN1, err := x509.MarshalPKIXPublicKey(pub)
fatalIfErr(err, "failed to encode public key")
var spki struct {
Algorithm pkix.AlgorithmIdentifier
SubjectPublicKey asn1.BitString
}
_, err = asn1.Unmarshal(spkiASN1, &spki)
fatalIfErr(err, "failed to decode public key")
skid := sha1.Sum(spki.SubjectPublicKey.Bytes)
tpl := &x509.Certificate{
SerialNumber: randomSerialNumber(),
Subject: pkix.Name{
Organization: []string{"mkcert development CA"},
OrganizationalUnit: []string{userAndHostname},
// The CommonName is required by iOS to show the certificate in the
// "Certificate Trust Settings" menu.
// https://github.com/FiloSottile/mkcert/issues/47
CommonName: "mkcert " + userAndHostname,
},
SubjectKeyId: skid[:],
NotAfter: time.Now().AddDate(10, 0, 0),
NotBefore: time.Now(),
KeyUsage: x509.KeyUsageCertSign,
BasicConstraintsValid: true,
IsCA: true,
MaxPathLenZero: true,
}
cert, err := x509.CreateCertificate(rand.Reader, tpl, tpl, pub, priv)
fatalIfErr(err, "failed to generate CA certificate")
privDER, err := x509.MarshalPKCS8PrivateKey(priv)
fatalIfErr(err, "failed to encode CA key")
err = ioutil.WriteFile(filepath.Join(m.CAROOT, rootKeyName), pem.EncodeToMemory(
&pem.Block{Type: "PRIVATE KEY", Bytes: privDER}), 0400)
fatalIfErr(err, "failed to save CA key")
err = ioutil.WriteFile(filepath.Join(m.CAROOT, rootName), pem.EncodeToMemory(
&pem.Block{Type: "CERTIFICATE", Bytes: cert}), 0644)
fatalIfErr(err, "failed to save CA certificate")
log.Printf("Created a new local CA 💥\n")
}
func (m *mkcert) caUniqueName() string {
return "mkcert development CA " + m.caCert.SerialNumber.String()
}