mirror of
https://github.com/slackhq/nebula.git
synced 2024-12-22 12:18:30 +00:00
340 lines
8.9 KiB
Go
340 lines
8.9 KiB
Go
package main
|
|
|
|
import (
|
|
"crypto/ecdh"
|
|
"crypto/rand"
|
|
"flag"
|
|
"fmt"
|
|
"io"
|
|
"net/netip"
|
|
"os"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/skip2/go-qrcode"
|
|
"github.com/slackhq/nebula/cert"
|
|
"github.com/slackhq/nebula/pkclient"
|
|
"golang.org/x/crypto/curve25519"
|
|
)
|
|
|
|
type signFlags struct {
|
|
set *flag.FlagSet
|
|
caKeyPath *string
|
|
caCertPath *string
|
|
name *string
|
|
ip *string
|
|
duration *time.Duration
|
|
inPubPath *string
|
|
outKeyPath *string
|
|
outCertPath *string
|
|
outQRPath *string
|
|
groups *string
|
|
subnets *string
|
|
p11url *string
|
|
}
|
|
|
|
func newSignFlags() *signFlags {
|
|
sf := signFlags{set: flag.NewFlagSet("sign", flag.ContinueOnError)}
|
|
sf.set.Usage = func() {}
|
|
sf.caKeyPath = sf.set.String("ca-key", "ca.key", "Optional: path to the signing CA key")
|
|
sf.caCertPath = sf.set.String("ca-crt", "ca.crt", "Optional: path to the signing CA cert")
|
|
sf.name = sf.set.String("name", "", "Required: name of the cert, usually a hostname")
|
|
sf.ip = sf.set.String("ip", "", "Required: ipv4 address and network in CIDR notation to assign the cert")
|
|
sf.duration = sf.set.Duration("duration", 0, "Optional: how long the cert should be valid for. The default is 1 second before the signing cert expires. Valid time units are seconds: \"s\", minutes: \"m\", hours: \"h\"")
|
|
sf.inPubPath = sf.set.String("in-pub", "", "Optional (if out-key not set): path to read a previously generated public key")
|
|
sf.outKeyPath = sf.set.String("out-key", "", "Optional (if in-pub not set): path to write the private key to")
|
|
sf.outCertPath = sf.set.String("out-crt", "", "Optional: path to write the certificate to")
|
|
sf.outQRPath = sf.set.String("out-qr", "", "Optional: output a qr code image (png) of the certificate")
|
|
sf.groups = sf.set.String("groups", "", "Optional: comma separated list of groups")
|
|
sf.subnets = sf.set.String("subnets", "", "Optional: comma separated list of ipv4 address and network in CIDR notation. Subnets this cert can serve for")
|
|
sf.p11url = p11Flag(sf.set)
|
|
return &sf
|
|
}
|
|
|
|
func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error {
|
|
sf := newSignFlags()
|
|
err := sf.set.Parse(args)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
isP11 := len(*sf.p11url) > 0
|
|
|
|
if !isP11 {
|
|
if err := mustFlagString("ca-key", sf.caKeyPath); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
if err := mustFlagString("ca-crt", sf.caCertPath); err != nil {
|
|
return err
|
|
}
|
|
if err := mustFlagString("name", sf.name); err != nil {
|
|
return err
|
|
}
|
|
if err := mustFlagString("ip", sf.ip); err != nil {
|
|
return err
|
|
}
|
|
if !isP11 && *sf.inPubPath != "" && *sf.outKeyPath != "" {
|
|
return newHelpErrorf("cannot set both -in-pub and -out-key")
|
|
}
|
|
|
|
var curve cert.Curve
|
|
var caKey []byte
|
|
|
|
if !isP11 {
|
|
var rawCAKey []byte
|
|
rawCAKey, err := os.ReadFile(*sf.caKeyPath)
|
|
|
|
if err != nil {
|
|
return fmt.Errorf("error while reading ca-key: %s", err)
|
|
}
|
|
|
|
// naively attempt to decode the private key as though it is not encrypted
|
|
caKey, _, curve, err = cert.UnmarshalSigningPrivateKeyFromPEM(rawCAKey)
|
|
if err == cert.ErrPrivateKeyEncrypted {
|
|
// ask for a passphrase until we get one
|
|
var passphrase []byte
|
|
for i := 0; i < 5; i++ {
|
|
out.Write([]byte("Enter passphrase: "))
|
|
passphrase, err = pr.ReadPassword()
|
|
|
|
if err == ErrNoTerminal {
|
|
return fmt.Errorf("ca-key is encrypted and must be decrypted interactively")
|
|
} else if err != nil {
|
|
return fmt.Errorf("error reading password: %s", err)
|
|
}
|
|
|
|
if len(passphrase) > 0 {
|
|
break
|
|
}
|
|
}
|
|
if len(passphrase) == 0 {
|
|
return fmt.Errorf("cannot open encrypted ca-key without passphrase")
|
|
}
|
|
|
|
curve, caKey, _, err = cert.DecryptAndUnmarshalSigningPrivateKey(passphrase, rawCAKey)
|
|
if err != nil {
|
|
return fmt.Errorf("error while parsing encrypted ca-key: %s", err)
|
|
}
|
|
} else if err != nil {
|
|
return fmt.Errorf("error while parsing ca-key: %s", err)
|
|
}
|
|
}
|
|
|
|
rawCACert, err := os.ReadFile(*sf.caCertPath)
|
|
if err != nil {
|
|
return fmt.Errorf("error while reading ca-crt: %s", err)
|
|
}
|
|
|
|
caCert, _, err := cert.UnmarshalCertificateFromPEM(rawCACert)
|
|
if err != nil {
|
|
return fmt.Errorf("error while parsing ca-crt: %s", err)
|
|
}
|
|
|
|
if !isP11 {
|
|
if err := caCert.VerifyPrivateKey(curve, caKey); err != nil {
|
|
return fmt.Errorf("refusing to sign, root certificate does not match private key")
|
|
}
|
|
}
|
|
|
|
if caCert.Expired(time.Now()) {
|
|
return fmt.Errorf("ca certificate is expired")
|
|
}
|
|
|
|
// if no duration is given, expire one second before the root expires
|
|
if *sf.duration <= 0 {
|
|
*sf.duration = time.Until(caCert.NotAfter()) - time.Second*1
|
|
}
|
|
|
|
network, err := netip.ParsePrefix(*sf.ip)
|
|
if err != nil {
|
|
return newHelpErrorf("invalid ip definition: %s", *sf.ip)
|
|
}
|
|
if !network.Addr().Is4() {
|
|
return newHelpErrorf("invalid ip definition: can only be ipv4, have %s", *sf.ip)
|
|
}
|
|
|
|
var groups []string
|
|
if *sf.groups != "" {
|
|
for _, rg := range strings.Split(*sf.groups, ",") {
|
|
g := strings.TrimSpace(rg)
|
|
if g != "" {
|
|
groups = append(groups, g)
|
|
}
|
|
}
|
|
}
|
|
|
|
var subnets []netip.Prefix
|
|
if *sf.subnets != "" {
|
|
for _, rs := range strings.Split(*sf.subnets, ",") {
|
|
rs := strings.Trim(rs, " ")
|
|
if rs != "" {
|
|
s, err := netip.ParsePrefix(rs)
|
|
if err != nil {
|
|
return newHelpErrorf("invalid subnet definition: %s", rs)
|
|
}
|
|
if !s.Addr().Is4() {
|
|
return newHelpErrorf("invalid subnet definition: can only be ipv4, have %s", rs)
|
|
}
|
|
subnets = append(subnets, s)
|
|
}
|
|
}
|
|
}
|
|
|
|
var pub, rawPriv []byte
|
|
var p11Client *pkclient.PKClient
|
|
|
|
if isP11 {
|
|
curve = cert.Curve_P256
|
|
p11Client, err = pkclient.FromUrl(*sf.p11url)
|
|
if err != nil {
|
|
return fmt.Errorf("error while creating PKCS#11 client: %w", err)
|
|
}
|
|
defer func(client *pkclient.PKClient) {
|
|
_ = client.Close()
|
|
}(p11Client)
|
|
}
|
|
|
|
if *sf.inPubPath != "" {
|
|
var pubCurve cert.Curve
|
|
rawPub, err := os.ReadFile(*sf.inPubPath)
|
|
if err != nil {
|
|
return fmt.Errorf("error while reading in-pub: %s", err)
|
|
}
|
|
|
|
pub, _, pubCurve, err = cert.UnmarshalPublicKeyFromPEM(rawPub)
|
|
if err != nil {
|
|
return fmt.Errorf("error while parsing in-pub: %s", err)
|
|
}
|
|
if pubCurve != curve {
|
|
return fmt.Errorf("curve of in-pub does not match ca")
|
|
}
|
|
} else if isP11 {
|
|
pub, err = p11Client.GetPubKey()
|
|
if err != nil {
|
|
return fmt.Errorf("error while getting public key with PKCS#11: %w", err)
|
|
}
|
|
} else {
|
|
pub, rawPriv = newKeypair(curve)
|
|
}
|
|
|
|
t := &cert.TBSCertificate{
|
|
Version: cert.Version1,
|
|
Name: *sf.name,
|
|
Networks: []netip.Prefix{network},
|
|
Groups: groups,
|
|
UnsafeNetworks: subnets,
|
|
NotBefore: time.Now(),
|
|
NotAfter: time.Now().Add(*sf.duration),
|
|
PublicKey: pub,
|
|
IsCA: false,
|
|
Curve: curve,
|
|
}
|
|
|
|
if *sf.outKeyPath == "" {
|
|
*sf.outKeyPath = *sf.name + ".key"
|
|
}
|
|
|
|
if *sf.outCertPath == "" {
|
|
*sf.outCertPath = *sf.name + ".crt"
|
|
}
|
|
|
|
if _, err := os.Stat(*sf.outCertPath); err == nil {
|
|
return fmt.Errorf("refusing to overwrite existing cert: %s", *sf.outCertPath)
|
|
}
|
|
|
|
var c cert.Certificate
|
|
|
|
if p11Client == nil {
|
|
c, err = t.Sign(caCert, curve, caKey)
|
|
if err != nil {
|
|
return fmt.Errorf("error while signing: %w", err)
|
|
}
|
|
} else {
|
|
c, err = t.SignPkcs11(caCert, curve, p11Client)
|
|
if err != nil {
|
|
return fmt.Errorf("error while signing with PKCS#11: %w", err)
|
|
}
|
|
}
|
|
|
|
if !isP11 && *sf.inPubPath == "" {
|
|
if _, err := os.Stat(*sf.outKeyPath); err == nil {
|
|
return fmt.Errorf("refusing to overwrite existing key: %s", *sf.outKeyPath)
|
|
}
|
|
|
|
err = os.WriteFile(*sf.outKeyPath, cert.MarshalPrivateKeyToPEM(curve, rawPriv), 0600)
|
|
if err != nil {
|
|
return fmt.Errorf("error while writing out-key: %s", err)
|
|
}
|
|
}
|
|
|
|
b, err := c.MarshalPEM()
|
|
if err != nil {
|
|
return fmt.Errorf("error while marshalling certificate: %s", err)
|
|
}
|
|
|
|
err = os.WriteFile(*sf.outCertPath, b, 0600)
|
|
if err != nil {
|
|
return fmt.Errorf("error while writing out-crt: %s", err)
|
|
}
|
|
|
|
if *sf.outQRPath != "" {
|
|
b, err = qrcode.Encode(string(b), qrcode.Medium, -5)
|
|
if err != nil {
|
|
return fmt.Errorf("error while generating qr code: %s", err)
|
|
}
|
|
|
|
err = os.WriteFile(*sf.outQRPath, b, 0600)
|
|
if err != nil {
|
|
return fmt.Errorf("error while writing out-qr: %s", err)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func newKeypair(curve cert.Curve) ([]byte, []byte) {
|
|
switch curve {
|
|
case cert.Curve_CURVE25519:
|
|
return x25519Keypair()
|
|
case cert.Curve_P256:
|
|
return p256Keypair()
|
|
default:
|
|
return nil, nil
|
|
}
|
|
}
|
|
|
|
func x25519Keypair() ([]byte, []byte) {
|
|
privkey := make([]byte, 32)
|
|
if _, err := io.ReadFull(rand.Reader, privkey); err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
pubkey, err := curve25519.X25519(privkey, curve25519.Basepoint)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
return pubkey, privkey
|
|
}
|
|
|
|
func p256Keypair() ([]byte, []byte) {
|
|
privkey, err := ecdh.P256().GenerateKey(rand.Reader)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
pubkey := privkey.PublicKey()
|
|
return pubkey.Bytes(), privkey.Bytes()
|
|
}
|
|
|
|
func signSummary() string {
|
|
return "sign <flags>: create and sign a certificate"
|
|
}
|
|
|
|
func signHelp(out io.Writer) {
|
|
sf := newSignFlags()
|
|
out.Write([]byte("Usage of " + os.Args[0] + " " + signSummary() + "\n"))
|
|
sf.set.SetOutput(out)
|
|
sf.set.PrintDefaults()
|
|
}
|