Fix ServerLoginSuccess in GreaterEqual Minecraft_1_16 to use ReadUUID…

…IntArray

pkg/edition/java/proto/packet/login.go

@@ -292,7 +292,7 @@ func (s *ServerLoginSuccess) Decode(c *proto.PacketContext, rd io.Reader) (err e
 	if c.Protocol.GreaterEqual(version.Minecraft_1_19) {
 		s.UUID, err = util.ReadUUID(rd)
 	} else if c.Protocol.GreaterEqual(version.Minecraft_1_16) {
-		s.UUID, err = util.ReadUUID(rd) // readUUIDIntArray?
+		s.UUID, err = util.ReadUUIDIntArray(rd)
 	} else {
 		var uuidString string
 		if c.Protocol.GreaterEqual(version.Minecraft_1_7_6) {

pkg/edition/java/proto/util/reader.go

@@ -328,6 +328,35 @@ func ReadUUID(rd io.Reader) (id uuid.UUID, err error) {
 	return uuid.FromBytes(b)
 }
 
+func ReadUUIDIntArray(rd io.Reader) (uuid.UUID, error) {
+	msbHigh, err := ReadInt(rd)
+	if err != nil {
+		return uuid.UUID{}, err
+	}
+	msbLow, err := ReadInt(rd)
+	if err != nil {
+		return uuid.UUID{}, err
+	}
+	lsbHigh, err := ReadInt(rd)
+	if err != nil {
+		return uuid.UUID{}, err
+	}
+	lsbLow, err := ReadInt(rd)
+	if err != nil {
+		return uuid.UUID{}, err
+	}
+	msb := int64(msbHigh)<<32 | int64(msbLow)&0xFFFFFFFF
+	lsb := int64(lsbHigh)<<32 | int64(lsbLow)&0xFFFFFFFF
+
+	return uuid.FromBytes(append(int64ToBytes(msb), int64ToBytes(lsb)...))
+}
+
+func int64ToBytes(i int64) []byte {
+	var buf [8]byte
+	binary.BigEndian.PutUint64(buf[:], uint64(i))
+	return buf[:]
+}
+
 func ReadProperties(rd io.Reader) (props []profile.Property, err error) {
 	var size int
 	size, err = ReadVarInt(rd)

pkg/edition/java/proto/util/util_test.go

@@ -3,6 +3,7 @@ package util
 import (
 	"bytes"
 	"github.com/stretchr/testify/require"
+	"go.minekube.com/gate/pkg/util/uuid"
 	"testing"
 )
 
@@ -21,3 +22,20 @@ func TestUTF(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, "test", s)
 }
+
+func TestUUIDIntArray(t *testing.T) {
+	// Generate a random UUID
+	id := uuid.New()
+
+	// Create a buffer and write the UUID to it as an integer array
+	buf := new(bytes.Buffer)
+	err := WriteUUIDIntArray(buf, id)
+	require.NoError(t, err)
+
+	// Read the UUID from the buffer
+	readID, err := ReadUUIDIntArray(buf)
+	require.NoError(t, err)
+
+	// The read UUID should be the same as the original UUID
+	require.Equal(t, id, readID)
+}

pkg/edition/java/proto/util/writer.go

@@ -3,14 +3,13 @@ package util
 import (
 	"encoding/binary"
 	"fmt"
-	"io"
-	"math"
-	"strings"
-
 	"go.minekube.com/common/minecraft/component"
 	"go.minekube.com/gate/pkg/edition/java/profile"
 	"go.minekube.com/gate/pkg/gate/proto"
 	"go.minekube.com/gate/pkg/util/uuid"
+	"io"
+	"math"
+	"strings"
 )
 
 func WriteString(writer io.Writer, val string) (err error) {
@@ -193,46 +192,26 @@ func WriteProperties(wr io.Writer, properties []profile.Property) error {
 	return nil
 }
 
-/*
-func WriteUUIDIntArray(wr io.Writer, uuid [16]byte) (err error) {
-	err = WriteInt32(wr, ByteArrayToInt32(uuid[:3]))
-	if err != nil {
-		return err
-	}
-	err = WriteInt32(wr, ByteArrayToInt32(uuid[4:7]))
+func WriteUUIDIntArray(wr io.Writer, id uuid.UUID) error {
+	msb := binary.BigEndian.Uint64(id[:8])
+	lsb := binary.BigEndian.Uint64(id[8:])
+
+	err := WriteUint32(wr, uint32(msb>>32))
 	if err != nil {
 		return err
 	}
-	err = WriteInt32(wr, ByteArrayToInt32(uuid[8:10]))
+	err = WriteUint32(wr, uint32(msb))
 	if err != nil {
 		return err
 	}
-	err = WriteInt32(wr, ByteArrayToInt32(uuid[11:13]))
+	err = WriteUint32(wr, uint32(lsb>>32))
 	if err != nil {
 		return err
 	}
-	return
-}
-
-func Int32ToByteArray(num int32) []byte {
-	size := int(unsafe.Sizeof(num))
-	arr := make([]byte, size)
-	for i := 0 ; i < size ; i++ {
-		byt := *(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&num)) + uintptr(i)))
-		arr[i] = byt
-	}
-	return arr
+	err = WriteUint32(wr, uint32(lsb))
+	return err
 }
 
-func ByteArrayToInt32(arr []byte) int32{
-	val := int32(0)
-	size := len(arr)
-	for i := 0 ; i < size ; i++ {
-		*(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&val)) + uintptr(i))) = arr[i]
-	}
-	return val
-}*/
-
 func WriteBytes17(wr io.Writer, b []byte, allowExtended bool) error {
 	if allowExtended {
 		if len(b) > ForgeMaxArrayLength {