server: implement REP_LOGIN key exchange

protocol/encrypt.go

@@ -1,8 +1,12 @@
 package protocol
 
+import (
+	"encoding/binary"
+)
+
 const (
-	E_KEY      = "m@rQn~W#"
+	DEFAULT_KEY = "m@rQn~W#"
-	KEY_LENGTH = 8
+	KEY_LENGTH  = 8
 )
 
 func encrypt_byte_change_A(ERSize int, data []byte) int {
@@ -43,3 +47,14 @@ func DecryptData(buff, key []byte) {
 	size := encrypt_byte_change_A(ERSize, buff)
 	xorData(buff, key, size)
 }
+
+func CreateNewKey(uTime uint64, iv1, iv2 uint64) []byte {
+	num := iv1 + 1
+	num2 := iv2 + 1
+
+	dEKey := uint64(binary.LittleEndian.Uint64([]byte(DEFAULT_KEY)))
+	key := dEKey * (uTime * num * num2)
+	buf := make([]byte, 8)
+	binary.LittleEndian.PutUint64(buf, uint64(key))
+	return buf
+}

server/client.go

@@ -5,21 +5,30 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"time"
 
 	"github.com/CPunch/GopenFusion/protocol"
 )
 
+const (
+	USE_E = iota
+	USE_FE
+)
+
 type Client struct {
-	server *Server
+	server   *Server
-	conn   net.Conn
+	conn     net.Conn
-	key    []byte
+	e_key    []byte
+	fe_key   []byte
+	whichKey int
 }
 
-func newClient(server *Server, conn net.Conn, key []byte) *Client {
+func newClient(server *Server, conn net.Conn) *Client {
 	return &Client{
-		server: server,
+		server:   server,
-		conn:   conn,
+		conn:     conn,
-		key:    key,
+		e_key:    []byte(protocol.DEFAULT_KEY),
+		whichKey: USE_E,
 	}
 }
 
@@ -41,7 +50,12 @@ func (client *Client) Send(data interface{}, typeID uint32) {
 	tmp = append(tmp, pkt.Buf...)
 
 	// encrypt typeID & body
-	protocol.EncryptData(tmp, client.key)
+	switch client.whichKey {
+	case USE_E:
+		protocol.EncryptData(tmp, client.e_key)
+	case USE_FE:
+		protocol.EncryptData(tmp, client.fe_key)
+	}
 
 	// write packet body
 	if _, err := client.conn.Write(tmp); err != nil {
@@ -50,6 +64,34 @@ func (client *Client) Send(data interface{}, typeID uint32) {
 	log.Printf("sent!")
 }
 
+func (client *Client) Login(pkt *protocol.Packet) {
+	var loginPkt protocol.SP_CL2LS_REQ_LOGIN
+	pkt.Decode(&loginPkt)
+	log.Printf("Got packet: %#v", loginPkt)
+
+	// !! TODO
+	resp := &protocol.SP_LS2CL_REP_LOGIN_SUCC{
+		SZID:          loginPkt.SZID,
+		ICharCount:    0,
+		ISlotNum:      1,
+		IPaymentFlag:  1,
+		IOpenBetaFlag: 0,
+		UISvrTime:     uint64(time.Now().Unix()),
+	}
+
+	client.Send(resp, protocol.P_LS2CL_REP_LOGIN_SUCC)
+	client.e_key = protocol.CreateNewKey(
+		resp.UISvrTime,
+		uint64(resp.ICharCount+1),
+		uint64(resp.ISlotNum+1),
+	)
+	client.fe_key = protocol.CreateNewKey(
+		binary.LittleEndian.Uint64([]byte(protocol.DEFAULT_KEY)),
+		uint64(loginPkt.IClientVerC),
+		1,
+	)
+}
+
 func (client *Client) ClientHandler() {
 	defer func() {
 		if err := recover(); err != nil {
@@ -78,22 +120,14 @@ func (client *Client) ClientHandler() {
 		}
 
 		// decrypt && grab typeID
-		protocol.DecryptData(tmp[:sz], client.key)
+		protocol.DecryptData(tmp[:sz], client.e_key)
 		typeID := int(binary.LittleEndian.Uint32(tmp[:4]))
 
 		log.Printf("Got packet ID: %x, with a sizeof: %d\n", typeID, sz)
 		pkt := protocol.NewPacket(tmp[4:sz])
 		switch typeID {
 		case protocol.P_CL2LS_REQ_LOGIN:
-			var loginPkt protocol.SP_CL2LS_REQ_LOGIN
+			client.Login(pkt)
-			pkt.Decode(&loginPkt)
-			log.Printf("Got packet: %#v", loginPkt)
-
-			client.Send(&protocol.SP_LS2CL_REP_LOGIN_FAIL{
-				IErrorCode: protocol.LOGIN_FAIL_EULA_ERROR,
-				SZID:       loginPkt.SZID,
-			}, protocol.P_LS2CL_REP_LOGIN_FAIL)
-
 		default:
 			log.Printf("[WARN] unsupported packet ID: %x\n", typeID)
 		}

server/server.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"log"
 	"net"
-
-	"github.com/CPunch/GopenFusion/protocol"
 )
 
 type Server struct {
@@ -42,7 +40,7 @@ func (server *Server) Start() {
 				return
 			}
 
-			client := newClient(server, conn, []byte(protocol.E_KEY))
+			client := newClient(server, conn)
 			server.clients[client] = true
 			go client.ClientHandler()
 			fmt.Printf("Client %p connected\n", client)

tools/genstructs.py

@@ -5,7 +5,7 @@
     Takes raw structures from a decompiled 'Assembly - CSharp.dll' from a main.unity3d fusionfall beta client,
     and transpiles them to gopenfusion's custom packet structure & tags. This requires a compiler installed,
     since struct field padding is grabbed via the `offsetof()` C macro. Some manual rearranging of structures
-    from the disassembled source might be needed. This script can also be used to generate c-style structures
+    from the disassembled source might be needed. This script can also be modified to generate c-style structures
     (because it already does!)
 
     usage: ./genstructs.py [IN.cs] > structs.go
@@ -173,10 +173,8 @@ class StructTranspiler:
 
     def toCStyle(self) -> str:
         source = "typedef struct {\n"
-
         for field in self.fields:
             source += "\t%s %s;\n" % (field.ctype, field.cname)
-
         source += "} %s;\n" % self.name
 
         for field in self.fields:
@@ -229,7 +227,6 @@ class StructTranspiler:
         source += "\n}\n"
         return source
 
-
 if __name__ == '__main__':
     inFilePath = sys.argv[1]
 
@@ -245,6 +242,7 @@ if __name__ == '__main__':
         except:
             break
 
+    # check for undefined types in structures and patch the sizes
     for i in range(len(structs)):
         struct = structs[i]
         f = struct.needsPatching()
@@ -252,10 +250,10 @@ if __name__ == '__main__':
             name = struct.fields[f].type
             for s in structs:
                 if s.name == name:
-                    if struct.fields[f].size > 1:
+                    if struct.fields[f].size > 1: # was it an array?
                         structs[i].fields[f].type = ("[%d]" % struct.fields[f].size) + struct.fields[f].type
-                    structs[i].fields[f].size *= s.size
+                    structs[i].fields[f].size *= s.size # field's size was set to 1 even if it wasn't an array
-                    structs[i].fields[f].needsPatching = False
+                    structs[i].fields[f].needsPatching = False # mark done
 
             f = struct.needsPatching()
 
@@ -272,10 +270,12 @@ if __name__ == '__main__':
     compiler.compile(['tmp.c'])
     compiler.link_executable(['tmp.o'], 'tmp')
 
+    # patch padding bytes
     lines = subprocess.getoutput(['./tmp']).splitlines()
     for i in range(len(structs)):
         structs[i].populatePadding(lines[i].split(" "))
 
+    # emit structures
     for struct in structs:
         print(struct.toGoStyle())