fix packet header size attack

Author: USS-Shenzhou

subspace/src/network/ClientTcpConnection.cpp

@@ -77,6 +77,11 @@ namespace subspace {
                     disconnect();
                     return;
                 }
+                if (headerBufValue > 2 * 1024 * 1024) {
+                    spdlog::warn("Packet too big: {}", headerBufValue);
+                    disconnect();
+                    return;
+                }
                 extractContent(headerBufValue);
             } else {
                 headerBufOffsetBit += 7;

subspace/src/network/ServerConnection.cpp

@@ -6,7 +6,8 @@
 
 namespace subspace {
     ServerConnection::ServerConnection(asio::ip::tcp::socket socket) :
-        BaseConnection(CryptHelper::NULL_ENCODE_DECODE, CryptHelper::AES_GCM_DECODE), socket(std::move(socket)), handshakeTimer(this->socket.get_executor()) {}
+        BaseConnection(CryptHelper::NULL_ENCODE_DECODE, CryptHelper::AES_GCM_DECODE), socket(std::move(socket)), handshakeTimer(this->socket.get_executor()) {
+    }
 
     void ServerConnection::start() {
         socket.set_option(asio::ip::tcp::no_delay(true));
@@ -41,6 +42,11 @@ namespace subspace {
                     disconnect();
                     return;
                 }
+                if (headerBufValue > 2 * 1024 * 1024) {
+                    spdlog::warn("Packet too big: {}", headerBufValue);
+                    disconnect();
+                    return;
+                }
                 extractContent(headerBufValue);
             } else {
                 headerBufOffsetBit += 7;