Initial commit

net/packets/bedrock/login.go

@@ -0,0 +1,165 @@
+package bedrock
+
+import (
+	"encoding/base64"
+	"encoding/binary"
+	"encoding/json"
+	"strings"
+
+	"github.com/cubexteam/Frodding/net/info"
+	"github.com/cubexteam/Frodding/net/packets"
+	"github.com/google/uuid"
+)
+
+type LoginPacket struct {
+	*packets.Packet
+	Protocol     int32
+	Username     string
+	ClientUUID   uuid.UUID
+	ClientXUID   string
+	ClientID     int64
+	ServerAddr   string
+	Language     string
+	SkinID       string
+	SkinData     []byte
+	CapeData     []byte
+	GeometryName string
+	GeometryData string
+}
+
+func NewLoginPacket() *LoginPacket {
+	return &LoginPacket{
+		Packet:     packets.NewPacket(info.IDLogin),
+		ClientUUID: uuid.New(),
+	}
+}
+
+func (pk *LoginPacket) Encode() {}
+
+func (pk *LoginPacket) Decode() {
+	pk.Protocol = pk.GetInt()
+	pk.GetByte()
+	totalLen := int(pk.GetUVarInt())
+	if totalLen <= 0 || totalLen > pk.Remaining() {
+		pk.Username = "Player"
+		return
+	}
+	blob := pk.GetBytes(totalLen)
+	if len(blob) < 4 {
+		pk.Username = "Player"
+		return
+	}
+	chainLen := int(binary.LittleEndian.Uint32(blob[:4]))
+	if chainLen <= 0 || 4+chainLen > len(blob) {
+		pk.Username = "Player"
+		return
+	}
+	var chainData struct {
+		Chain []string `json:"chain"`
+	}
+	if err := json.Unmarshal(blob[4:4+chainLen], &chainData); err == nil {
+		for _, raw := range chainData.Chain {
+			pk.parseChain(raw)
+		}
+	}
+	offset := 4 + chainLen
+	if offset+4 > len(blob) {
+		if pk.Username == "" {
+			pk.Username = "Player"
+		}
+		return
+	}
+	clientLen := int(binary.LittleEndian.Uint32(blob[offset : offset+4]))
+	offset += 4
+	if clientLen > 0 && offset+clientLen <= len(blob) {
+		pk.parseClientData(string(blob[offset : offset+clientLen]))
+	}
+	if pk.Username == "" {
+		pk.Username = "Player"
+	}
+}
+
+func decodeJWTPayload(s string) ([]byte, error) {
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		switch len(s) % 4 {
+		case 2:
+			s += "=="
+		case 3:
+			s += "="
+		}
+		b, err = base64.URLEncoding.DecodeString(s)
+	}
+	return b, err
+}
+
+func (pk *LoginPacket) parseChain(raw string) {
+	parts := strings.Split(raw, ".")
+	if len(parts) < 2 {
+		return
+	}
+	payload, err := decodeJWTPayload(parts[1])
+	if err != nil {
+		return
+	}
+	var data struct {
+		ExtraData map[string]interface{} `json:"extraData"`
+	}
+	if err := json.Unmarshal(payload, &data); err != nil || data.ExtraData == nil {
+		return
+	}
+	if v, ok := data.ExtraData["displayName"]; ok {
+		if name, _ := v.(string); name != "" {
+			pk.Username = name
+		}
+	}
+	if v, ok := data.ExtraData["identity"]; ok {
+		if idStr, _ := v.(string); idStr != "" {
+			if u, err := uuid.Parse(idStr); err == nil {
+				pk.ClientUUID = u
+			}
+		}
+	}
+	if v, ok := data.ExtraData["XUID"]; ok {
+		pk.ClientXUID, _ = v.(string)
+	}
+}
+
+func (pk *LoginPacket) parseClientData(raw string) {
+	parts := strings.Split(raw, ".")
+	if len(parts) < 2 {
+		return
+	}
+	payload, err := decodeJWTPayload(parts[1])
+	if err != nil {
+		return
+	}
+	var data struct {
+		ClientRandomID int64  `json:"ClientRandomId"`
+		ServerAddress  string `json:"ServerAddress"`
+		LanguageCode   string `json:"LanguageCode"`
+		SkinID         string `json:"SkinId"`
+		SkinData       string `json:"SkinData"`
+		CapeData       string `json:"CapeData"`
+		SkinGeomName   string `json:"SkinGeometryName"`
+		SkinGeomData   string `json:"SkinGeometry"`
+	}
+	if err := json.Unmarshal(payload, &data); err != nil {
+		return
+	}
+	pk.ClientID = data.ClientRandomID
+	pk.ServerAddr = data.ServerAddress
+	pk.Language = data.LanguageCode
+	if pk.Language == "" {
+		pk.Language = "en_US"
+	}
+	pk.SkinID = data.SkinID
+	pk.GeometryName = data.SkinGeomName
+	pk.SkinData, _ = base64.RawStdEncoding.DecodeString(data.SkinData)
+	pk.CapeData, _ = base64.RawStdEncoding.DecodeString(data.CapeData)
+	geomBytes, _ := base64.RawStdEncoding.DecodeString(data.SkinGeomData)
+	pk.GeometryData = string(geomBytes)
+	for len(pk.SkinData) < 8192 {
+		pk.SkinData = append(pk.SkinData, 0x00)
+	}
+}