Add TLS self sign generate command

cmd/sing-box/cmd_generate_tls.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"os"
+	"time"
+
+	"github.com/sagernet/sing-box/common/tls"
+	"github.com/sagernet/sing-box/log"
+
+	"github.com/spf13/cobra"
+)
+
+var flagGenerateTLSKeyPairMonths int
+
+var commandGenerateTLSKeyPair = &cobra.Command{
+	Use:   "tls-keypair <server_name>",
+	Short: "Generate TLS self sign key pair",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		err := generateTLSKeyPair(args[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+	},
+}
+
+func init() {
+	commandGenerateTLSKeyPair.Flags().IntVarP(&flagGenerateTLSKeyPairMonths, "months", "m", 1, "Valid months")
+	commandGenerate.AddCommand(commandGenerateTLSKeyPair)
+}
+
+func generateTLSKeyPair(serverName string) error {
+	privateKeyPem, publicKeyPem, err := tls.GenerateKeyPair(time.Now, serverName, time.Now().AddDate(0, flagGenerateTLSKeyPairMonths, 0))
+	if err != nil {
+		return err
+	}
+	os.Stdout.WriteString(string(privateKeyPem) + "\n")
+	os.Stdout.WriteString(string(publicKeyPem) + "\n")
+	return nil
+}