cmd: add Ed25519 key generation and Lua script signing

main/commands/all/lua/lua.go

@@ -0,0 +1,13 @@
+package lua
+
+import "github.com/xtls/xray-core/main/commands/base"
+
+// CmdLua holds the Lua script commands.
+var CmdLua = &base.Command{
+	UsageLine: "{{.Exec}} lua",
+	Short:     "Manage Lua scripts",
+	Long:      "{{.Exec}} {{.LongName}} provides tools for local Lua scripts.",
+	Commands: []*base.Command{
+		cmdSign,
+	},
+}

main/commands/all/lua/sign.go

@@ -0,0 +1,98 @@
+package lua
+
+import (
+	"os"
+	"path/filepath"
+
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/main/commands/base"
+)
+
+var cmdSign = &base.Command{
+	UsageLine: "{{.Exec}} lua sign [-key seed] [-o output-file] <input-file>",
+	Short:     "Sign a local Lua script for privileged execution",
+	Long: `
+Sign a local Lua file using a 32-byte Ed25519 private key seed in unpadded
+Base64URL. Use {{.Exec}} ed25519 to generate a key pair.
+Write back to the input file, or use -o to write another file (- for stdout).
+`,
+}
+
+var (
+	signKey    = cmdSign.Flag.String("key", "", "Ed25519 private key seed in unpadded Base64URL.")
+	signOutput = cmdSign.Flag.String("o", "", "Output file, or - for stdout. Default: input file.")
+)
+
+func init() {
+	cmdSign.Run = executeSign
+}
+
+func executeSign(cmd *base.Command, args []string) {
+	if len(args) != 1 {
+		cmd.Usage()
+	}
+
+	info, err := os.Stat(args[0])
+	if err != nil {
+		base.Fatalf("failed to inspect Lua file: %s", err)
+	}
+	if !info.Mode().IsRegular() {
+		base.Fatalf("Lua input is not a regular file: %s", args[0])
+	}
+
+	code, err := os.ReadFile(args[0])
+	if err != nil {
+		base.Fatalf("failed to read Lua file: %s", err)
+	}
+
+	signed, err := xlua.SignPrivilegedScript(code, *signKey)
+	if err != nil {
+		base.Fatalf("failed to sign Lua file: %s", err)
+	}
+
+	if *signOutput == "-" {
+		if _, err := os.Stdout.Write(signed); err != nil {
+			base.Fatalf("failed to write signed Lua file: %s", err)
+		}
+		return
+	}
+	output := *signOutput
+	if output == "" {
+		output = args[0]
+	}
+	if err := writeSignedFile(output, signed, info.Mode().Perm()); err != nil {
+		base.Fatalf("failed to write signed Lua file: %s", err)
+	}
+}
+
+func writeSignedFile(path string, code []byte, mode os.FileMode) error {
+	if info, err := os.Stat(path); err == nil {
+		if !info.Mode().IsRegular() {
+			return &os.PathError{Op: "write", Path: path, Err: os.ErrInvalid}
+		}
+		mode = info.Mode().Perm()
+		path, err = filepath.EvalSymlinks(path)
+		if err != nil {
+			return err
+		}
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+
+	file, err := os.CreateTemp(filepath.Dir(path), ".xray-lua-sign-*")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(file.Name())
+	defer file.Close()
+	if _, err := file.Write(code); err != nil {
+		return err
+	}
+	if err := file.Chmod(mode); err != nil {
+		return err
+	}
+	if err := file.Close(); err != nil {
+		return err
+	}
+	return os.Rename(file.Name(), path)
+}