CLI: Add lua encode command for inline scripts

common/lua/encode.go

@@ -0,0 +1,29 @@
+package lua
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+// Encode returns an inline script, optionally compressed with gzip at the highest level.
+func Encode(code []byte, zip bool) (string, error) {
+	if !zip {
+		return "base64:" + base64.StdEncoding.EncodeToString(code), nil
+	}
+
+	var data bytes.Buffer
+	writer, err := gzip.NewWriterLevel(&data, gzip.BestCompression)
+	if err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	if _, err := writer.Write(code); err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	if err := writer.Close(); err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	return "base64+gzip:" + base64.StdEncoding.EncodeToString(data.Bytes()), nil
+}

common/lua/encode_test.go

@@ -0,0 +1,88 @@
+package lua
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"strings"
+	"testing"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+func TestEncodeRoundTrip(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		code []byte
+	}{
+		{"empty", nil},
+		{"padding", []byte("x")},
+		{"unicode", []byte(`value = "你好"`)},
+		{"multiline", []byte("-- comment\r\nvalue = 42\n")},
+		{"binary", []byte{0, 0xff, 0xfe, 1, 2}},
+		{"large", bytes.Repeat([]byte("-- repeated code\n"), 32768)},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			for _, zip := range []bool{false, true} {
+				prefix := "base64:"
+				if zip {
+					prefix = "base64+gzip:"
+				}
+				t.Run(prefix, func(t *testing.T) {
+					script, err := Encode(tc.code, zip)
+					if err != nil {
+						t.Fatal(err)
+					}
+					encoded, ok := strings.CutPrefix(script, prefix)
+					if !ok {
+						t.Fatalf("encoded script does not start with %q", prefix)
+					}
+					code, err := decode(encoded, zip)
+					if err != nil {
+						t.Fatal(err)
+					}
+					if !bytes.Equal(code, tc.code) {
+						t.Fatal("decoded bytes differ from input")
+					}
+				})
+			}
+		})
+	}
+}
+
+func TestEncodeBestCompression(t *testing.T) {
+	script, err := Encode([]byte("value = 42"), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(script, "base64+gzip:"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The gzip XFL header byte is 2 for the highest compression level.
+	if len(data) < 10 || data[8] != 2 {
+		t.Fatal("gzip header does not indicate highest compression")
+	}
+}
+
+func TestEncodeCompile(t *testing.T) {
+	for _, zip := range []bool{false, true} {
+		script, err := Encode([]byte(`value = "你好"`), zip)
+		if err != nil {
+			t.Fatal(err)
+		}
+		program, err := Compile(script)
+		if err != nil {
+			t.Fatal(err)
+		}
+		state, err := program.NewState(context.Background(), nil, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got := state.GetGlobal("value"); got != glua.LString("你好") {
+			state.Close()
+			t.Fatalf("value = %v, want 你好", got)
+		}
+		state.Close()
+	}
+}