inital commit: we can read login packets!

server/server.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"encoding/binary"
+	"fmt"
+	"log"
+	"net"
+
+	"github.com/CPunch/GoFusion/api/protocol"
+)
+
+const (
+	E_KEY      = "m@rQn~W#"
+	KEY_LENGTH = 8
+)
+
+func encrypt_byte_change_A(ERSize int, data []byte) int {
+	var num, num2, num3 int
+
+	for num+ERSize <= len(data) {
+		num4 := num + num3
+		num5 := num + (ERSize - 1 - num3)
+
+		b := data[num4]
+		data[num4] = data[num5]
+		data[num5] = b
+		num += ERSize
+		num3++
+		if num3 > ERSize/2 {
+			num3 = 0
+		}
+	}
+
+	num2 = ERSize - (num + ERSize - len(data))
+	return num + num2
+}
+
+func xorData(buff, key []byte, size int) {
+	for i := 0; i < size; i++ {
+		buff[i] ^= key[i%KEY_LENGTH]
+	}
+}
+
+func decryptData(buff, key []byte) {
+	ERSize := len(buff)%(KEY_LENGTH/2+1)*2 + KEY_LENGTH
+	size := encrypt_byte_change_A(ERSize, buff)
+	xorData(buff, key, size)
+}
+
+func handle(conn net.Conn) {
+	defer func() {
+		conn.Close()
+	}()
+
+	tmp := make([]byte, 4)
+	for {
+		// grab packet size
+		if _, err := conn.Read(tmp); err != nil {
+			panic(fmt.Errorf("[FATAL] failed to read packet size! %v", err))
+		}
+
+		sz := int(binary.LittleEndian.Uint32(tmp))
+		pkt := protocol.NewPacket(sz)
+
+		if _, err := conn.Read(pkt.Buf); err != nil {
+			panic(fmt.Errorf("[FATAL] failed to read packet body! %v", err))
+		}
+
+		decryptData(pkt.Buf, []byte(E_KEY))
+		typeID := int(binary.LittleEndian.Uint32(pkt.Read(4)))
+		sizeof := len(pkt.Buf)
+		log.Printf("Got packet ID: %x\n", typeID)
+
+		pkt.ResetCursor()
+		switch typeID {
+		case protocol.P_CL2LS_REQ_LOGIN:
+			var loginPkt protocol.SP_CL2LS_REQ_LOGIN
+			pkt.Decode(&loginPkt)
+			log.Printf("Got packet: %#v, with a sizeof: %d", loginPkt, sizeof)
+		default:
+			log.Printf("[WARN] unsupported packet ID: %x\n", typeID)
+		}
+	}
+}
+
+func main() {
+	server, err := net.Listen("tcp", ":23000")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Print("Server hosted on 127.0.0.1:23000")
+	for {
+		conn, err := server.Accept()
+		if err != nil {
+			log.Println("Connection error: ", err)
+			return
+		}
+		go handle(conn)
+	}
+}