faster and more secure junk creation

device/junk_creator_test.go

@@ -0,0 +1,124 @@
+package device
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/amnezia-vpn/amneziawg-go/conn/bindtest"
+	"github.com/amnezia-vpn/amneziawg-go/tun/tuntest"
+)
+
+func setUpJunkCreator(t *testing.T) (junkCreator, error) {
+	cfg, _ := genASecurityConfigs(t)
+	tun := tuntest.NewChannelTUN()
+	binds := bindtest.NewChannelBinds()
+	level := LogLevelVerbose
+	dev := NewDevice(
+		tun.TUN(),
+		binds[0],
+		NewLogger(level, ""),
+	)
+
+	if err := dev.IpcSet(cfg[0]); err != nil {
+		t.Errorf("failed to configure device %v", err)
+		dev.Close()
+		return junkCreator{}, err
+	}
+
+	jc, err := NewJunkCreator(dev)
+
+	if err != nil {
+		t.Errorf("failed to create junk creator %v", err)
+		dev.Close()
+		return junkCreator{}, err
+	}
+
+	return jc, nil
+}
+
+func Test_junkCreator_createJunkPackets(t *testing.T) {
+	jc, err := setUpJunkCreator(t)
+	if err != nil {
+		return
+	}
+	t.Run("", func(t *testing.T) {
+		got, err := jc.createJunkPackets()
+		if err != nil {
+			t.Errorf(
+				"junkCreator.createJunkPackets() = %v; failed",
+				err,
+			)
+			return
+		}
+		seen := make(map[string]bool)
+		for _, junk := range got {
+			key := string(junk)
+			if seen[key] {
+				t.Errorf(
+					"junkCreator.createJunkPackets() = %v, duplicate key: %v",
+					got,
+					junk,
+				)
+				return
+			}
+			seen[key] = true
+		}
+	})
+}
+
+func Test_junkCreator_randomJunkWithSize(t *testing.T) {
+	t.Run("", func(t *testing.T) {
+		jc, err := setUpJunkCreator(t)
+		if err != nil {
+			return
+		}
+		r1, _ := jc.randomJunkWithSize(10)
+		r2, _ := jc.randomJunkWithSize(10)
+		fmt.Printf("%v\n%v\n", r1, r2)
+		if bytes.Equal(r1, r2) {
+			t.Errorf("same junks %v", err)
+			jc.device.Close()
+			return
+		}
+	})
+}
+
+func Test_junkCreator_randomPacketSize(t *testing.T) {
+	jc, err := setUpJunkCreator(t)
+	if err != nil {
+		return
+	}
+	for range [30]struct{}{} {
+		t.Run("", func(t *testing.T) {
+			if got := jc.randomPacketSize(); jc.device.aSecCfg.junkPacketMinSize > got ||
+				got > jc.device.aSecCfg.junkPacketMaxSize {
+				t.Errorf(
+					"junkCreator.randomPacketSize() = %v, not between range [%v,%v]",
+					got,
+					jc.device.aSecCfg.junkPacketMinSize,
+					jc.device.aSecCfg.junkPacketMaxSize,
+				)
+			}
+		})
+	}
+}
+
+func Test_junkCreator_appendJunk(t *testing.T) {
+	jc, err := setUpJunkCreator(t)
+	if err != nil {
+		return
+	}
+	t.Run("", func(t *testing.T) {
+		s := "apple"
+		buffer := bytes.NewBuffer([]byte(s))
+		err := jc.appendJunk(buffer, 30)
+		if err != nil &&
+			buffer.Len() != len(s)+30 {
+			t.Errorf("appendWithJunk() size don't match")
+		}
+		read := make([]byte, 50)
+		buffer.Read(read)
+		fmt.Println(string(read))
+	})
+}