http_protocol_handler: limit the number of starting newlines

contrib/epee/include/net/abstract_tcp_server2.inl

@@ -607,7 +607,7 @@ PRAGMA_WARNING_DISABLE_VS(4355)
     {
       if(ec == boost::asio::error::operation_aborted)
         return;
-      MDEBUG("Connection timeout, closing");
+      MDEBUG(context << "connection timeout, closing");
       self->close();
     });
   }

contrib/epee/include/net/http_protocol_handler.h

@@ -141,6 +141,7 @@ namespace net_utils
 			size_t m_len_summary, m_len_remain;
 			config_type& m_config;
 			bool m_want_close;
+			size_t m_newlines;
 		protected:
 			i_service_endpoint* m_psnd_hndlr; 
 		};

contrib/epee/include/net/http_protocol_handler.inl

@@ -38,6 +38,7 @@
 
 #define HTTP_MAX_URI_LEN		 9000 
 #define HTTP_MAX_HEADER_LEN		 100000
+#define HTTP_MAX_STARTING_NEWLINES       8
 
 namespace epee
 {
@@ -203,6 +204,7 @@ namespace net_utils
 		m_len_remain(0),
 		m_config(config), 
 		m_want_close(false),
+		m_newlines(0),
         m_psnd_hndlr(psnd_hndlr)
 	{
 
@@ -216,6 +218,7 @@ namespace net_utils
 		m_body_transfer_type = http_body_transfer_undefined;
 		m_query_info.clear();
 		m_len_summary = 0;
+		m_newlines = 0;
 		return true;
 	}
 	//--------------------------------------------------------------------------------------------
@@ -260,6 +263,13 @@ namespace net_utils
 				{
           //some times it could be that before query line cold be few line breaks
           //so we have to be calm without panic with assers
+					m_newlines += std::string::npos == ndel ? m_cache.size() : ndel;
+					if (m_newlines > HTTP_MAX_STARTING_NEWLINES)
+					{
+						LOG_ERROR("simple_http_connection_handler::handle_buff_out: Too many starting newlines");
+						m_state = http_state_error;
+						return false;
+					}
 					m_cache.erase(0, ndel);
 					break;
 				}