vault1984/oss/app/lib/tls.go

87 lines
2.4 KiB
Go

package lib
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"fmt"
"math/big"
"net"
"os"
"time"
)
// EnsureTLSCert checks if TLS cert/key exist at the configured paths.
// If not, generates a self-signed certificate valid for 10 years,
// covering localhost, 127.0.0.1, and all local LAN IPs.
func EnsureTLSCert(certPath, keyPath string) error {
_, certErr := os.Stat(certPath)
_, keyErr := os.Stat(keyPath)
if certErr == nil && keyErr == nil {
return nil // both exist
}
key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
return fmt.Errorf("generate key: %w", err)
}
serial, err := rand.Int(rand.Reader, new(big.Int).Lsh(big.NewInt(1), 128))
if err != nil {
return fmt.Errorf("serial: %w", err)
}
tmpl := x509.Certificate{
SerialNumber: serial,
Subject: pkix.Name{Organization: []string{"Vault1984"}, CommonName: "vault1984"},
NotBefore: time.Now().Add(-time.Hour),
NotAfter: time.Now().Add(10 * 365 * 24 * time.Hour),
KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
DNSNames: []string{"localhost", "vault1984.local"},
IPAddresses: []net.IP{net.IPv4(127, 0, 0, 1), net.IPv6loopback},
}
// Add all local interface IPs so LAN access works
if addrs, err := net.InterfaceAddrs(); err == nil {
for _, a := range addrs {
if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
tmpl.IPAddresses = append(tmpl.IPAddresses, ipnet.IP)
}
}
}
certDER, err := x509.CreateCertificate(rand.Reader, &tmpl, &tmpl, &key.PublicKey, key)
if err != nil {
return fmt.Errorf("create cert: %w", err)
}
certFile, err := os.Create(certPath)
if err != nil {
return fmt.Errorf("write cert: %w", err)
}
defer certFile.Close()
if err := pem.Encode(certFile, &pem.Block{Type: "CERTIFICATE", Bytes: certDER}); err != nil {
return fmt.Errorf("encode cert: %w", err)
}
keyDER, err := x509.MarshalECPrivateKey(key)
if err != nil {
return fmt.Errorf("marshal key: %w", err)
}
keyFile, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return fmt.Errorf("write key: %w", err)
}
defer keyFile.Close()
if err := pem.Encode(keyFile, &pem.Block{Type: "EC PRIVATE KEY", Bytes: keyDER}); err != nil {
return fmt.Errorf("encode key: %w", err)
}
return nil
}