epee: optionally restrict HTTP service to a configurable user agent

This is intended to catch traffic coming from a web browser,
so we avoid issues with a web page sending a transfer RPC to
the wallet. Requiring a particular user agent can act as a
simple password scheme, while we wait for 0MQ and proper
authentication to be merged.

contrib/epee/include/net/http_base.h

@@ -98,6 +98,7 @@ namespace net_utils
 			std::string m_content_encoding; //"Content-Encoding:"
 			std::string m_host;             //"Host:"
 			std::string m_cookie;			//"Cookie:"
+			std::string m_user_agent;	//"User-Agent:"
 			fields_list m_etc_fields;
 
 			void clear()
@@ -110,6 +111,7 @@ namespace net_utils
 				m_content_encoding.clear();
 				m_host.clear();
 				m_cookie.clear();
+				m_user_agent.clear();
 				m_etc_fields.clear();
 			}
 		};

contrib/epee/include/net/http_client.h

@@ -638,10 +638,10 @@ using namespace std;
 				LOG_FRAME("http_stream_filter::parse_cached_header(*)", LOG_LEVEL_4);
 				
 				STATIC_REGEXP_EXPR_1(rexp_mach_field, 
-					"\n?((Connection)|(Referer)|(Content-Length)|(Content-Type)|(Transfer-Encoding)|(Content-Encoding)|(Host)|(Cookie)"
+					"\n?((Connection)|(Referer)|(Content-Length)|(Content-Type)|(Transfer-Encoding)|(Content-Encoding)|(Host)|(Cookie)|(User-Agent)"
-					//  12            3         4                5              6                   7                  8      9    
+					//  12            3         4                5              6                   7                  8      9        10
 					"|([\\w-]+?)) ?: ?((.*?)(\r?\n))[^\t ]",	
-					//10             1112   13 
+					//11             1213   14
 					boost::regex::icase | boost::regex::normal);
 
 				boost::smatch		result;
@@ -653,8 +653,8 @@ using namespace std;
 				//lookup all fields and fill well-known fields
 				while( boost::regex_search( it_current_bound, it_end_bound, result, rexp_mach_field, boost::match_default) && result[0].matched) 
 				{
-					const size_t field_val = 12;
+					const size_t field_val = 13;
-					//const size_t field_etc_name = 10;
+					//const size_t field_etc_name = 11;
 
 					int i = 2; //start position = 2
 					if(result[i++].matched)//"Connection"
@@ -675,6 +675,8 @@ using namespace std;
 					}
 					else if(result[i++].matched)//"Cookie"
 						body_info.m_cookie = result[field_val];
+					else if(result[i++].matched)//"User-Agent"
+						body_info.m_user_agent = result[field_val];
 					else if(result[i++].matched)//e.t.c (HAVE TO BE MATCHED!)
 					{;}
 					else

contrib/epee/include/net/http_protocol_handler.h

@@ -49,6 +49,7 @@ namespace net_utils
 		struct http_server_config
 		{
 			std::string m_folder;
+			std::string m_required_user_agent;
 			critical_section m_lock;
 		};
 

contrib/epee/include/net/http_protocol_handler.inl

@@ -285,7 +285,8 @@ namespace net_utils
 						}	
 						break;
 					}
-					analize_cached_request_header_and_invoke_state(pos);
+					if (!analize_cached_request_header_and_invoke_state(pos))
+						return false;
 					break;
 				}
 			case http_state_retriving_body:
@@ -387,6 +388,14 @@ namespace net_utils
 		{
 			LOG_ERROR("simple_http_connection_handler<t_connection_context>::analize_cached_request_header_and_invoke_state(): failed to anilize request header: " << m_cache);
 			m_state = http_state_error;
+			return false;
+		}
+
+                if (!m_config.m_required_user_agent.empty() && m_query_info.m_header_info.m_user_agent != m_config.m_required_user_agent)
+                {
+			LOG_ERROR("simple_http_connection_handler<t_connection_context>::analize_cached_request_header_and_invoke_state(): unexpected user agent: " << m_query_info.m_header_info.m_user_agent);
+			m_state = http_state_error;
+			return false;
                 }
 
 		m_cache.erase(0, pos);
@@ -473,10 +482,10 @@ namespace net_utils
 		LOG_FRAME("http_stream_filter::parse_cached_header(*)", LOG_LEVEL_3);
 
 		STATIC_REGEXP_EXPR_1(rexp_mach_field, 
-			"\n?((Connection)|(Referer)|(Content-Length)|(Content-Type)|(Transfer-Encoding)|(Content-Encoding)|(Host)|(Cookie)"
+			"\n?((Connection)|(Referer)|(Content-Length)|(Content-Type)|(Transfer-Encoding)|(Content-Encoding)|(Host)|(Cookie)|(User-Agent)"
-			//  12            3         4                5              6                   7                  8      9    
+			//  12            3         4                5              6                   7                  8      9        10
 			"|([\\w-]+?)) ?: ?((.*?)(\r?\n))[^\t ]",	
-			//10             1112   13 
+			//11             1213   14 
 			boost::regex::icase | boost::regex::normal);
 
 		boost::smatch		result;
@@ -488,8 +497,8 @@ namespace net_utils
 		//lookup all fields and fill well-known fields
 		while( boost::regex_search( it_current_bound, it_end_bound, result, rexp_mach_field, boost::match_default) && result[0].matched) 
 		{
-			const size_t field_val = 12;
+			const size_t field_val = 13;
-			const size_t field_etc_name = 10;
+			const size_t field_etc_name = 11;
 
 			int i = 2; //start position = 2
 			if(result[i++].matched)//"Connection"
@@ -508,6 +517,8 @@ namespace net_utils
 				body_info.m_host = result[field_val];
 			else if(result[i++].matched)//"Cookie"
 				body_info.m_cookie = result[field_val];
+			else if(result[i++].matched)//"User-Agent"
+				body_info.m_user_agent = result[field_val];
 			else if(result[i++].matched)//e.t.c (HAVE TO BE MATCHED!)
 				body_info.m_etc_fields.push_back(std::pair<std::string, std::string>(result[field_etc_name], result[field_val]));
 			else

contrib/epee/include/net/http_server_impl_base.h

@@ -52,7 +52,7 @@ namespace epee
         : m_net_server(external_io_service)
     {}
 
-    bool init(const std::string& bind_port = "0", const std::string& bind_ip = "0.0.0.0")
+    bool init(const std::string& bind_port = "0", const std::string& bind_ip = "0.0.0.0", const std::string &user_agent = "")
     {
 
       //set self as callback handler
@@ -61,6 +61,9 @@ namespace epee
       //here set folder for hosting reqests
       m_net_server.get_config_object().m_folder = "";
 
+      // workaround till we get auth/encryption
+      m_net_server.get_config_object().m_required_user_agent = user_agent;
+
       LOG_PRINT_L0("Binding on " << bind_ip << ":" << bind_port);
       bool res = m_net_server.init_server(bind_port, bind_ip);
       if(!res)

src/common/command_line.cpp

@@ -48,6 +48,7 @@ namespace command_line
   const arg_descriptor<bool> arg_version = {"version", "Output version information"};
   const arg_descriptor<std::string> arg_data_dir = {"data-dir", "Specify data directory"};
   const arg_descriptor<std::string> arg_testnet_data_dir = {"testnet-data-dir", "Specify testnet data directory"};
+  const arg_descriptor<std::string> arg_user_agent = {"user-agent", "Restrict RPC use to clients using this user agent"};
   const arg_descriptor<bool>		arg_test_drop_download  		= {"test-drop-download", "For net tests: in download, discard ALL blocks instead checking/saving them (very fast)"};
   const arg_descriptor<uint64_t>	arg_test_drop_download_height  	= {"test-drop-download-height", "Like test-drop-download but disards only after around certain height", 0};
   const arg_descriptor<int> 		arg_test_dbg_lock_sleep = {"test-dbg-lock-sleep", "Sleep time in ms, defaults to 0 (off), used to debug before/after locking mutex. Values 100 to 1000 are good for tests."};

src/common/command_line.h

@@ -204,6 +204,7 @@ namespace command_line
   extern const arg_descriptor<bool> arg_version;
   extern const arg_descriptor<std::string> arg_data_dir;
   extern const arg_descriptor<std::string> arg_testnet_data_dir;
+  extern const arg_descriptor<std::string> arg_user_agent;
   extern const arg_descriptor<bool>		arg_test_drop_download;
   extern const arg_descriptor<uint64_t>	arg_test_drop_download_height;
   extern const arg_descriptor<int> 		arg_test_dbg_lock_sleep;

src/daemon/command_parser_executor.cpp

@@ -34,10 +34,11 @@ namespace daemonize {
 t_command_parser_executor::t_command_parser_executor(
     uint32_t ip
   , uint16_t port
+  , const std::string &user_agent
   , bool is_rpc
   , cryptonote::core_rpc_server* rpc_server
   )
-  : m_executor(ip, port, is_rpc, rpc_server)
+  : m_executor(ip, port, user_agent, is_rpc, rpc_server)
 {}
 
 bool t_command_parser_executor::print_peer_list(const std::vector<std::string>& args)

src/daemon/command_parser_executor.h

@@ -49,6 +49,7 @@ public:
   t_command_parser_executor(
       uint32_t ip
     , uint16_t port
+    , const std::string &user_agent
     , bool is_rpc
     , cryptonote::core_rpc_server* rpc_server = NULL
     );

src/daemon/command_server.cpp

@@ -37,10 +37,11 @@ namespace p = std::placeholders;
 t_command_server::t_command_server(
     uint32_t ip
   , uint16_t port
+  , const std::string &user_agent
   , bool is_rpc
   , cryptonote::core_rpc_server* rpc_server
   )
-  : m_parser(ip, port, is_rpc, rpc_server)
+  : m_parser(ip, port, user_agent, is_rpc, rpc_server)
   , m_command_lookup()
   , m_is_rpc(is_rpc)
 {

src/daemon/command_server.h

@@ -54,6 +54,7 @@ public:
   t_command_server(
       uint32_t ip
     , uint16_t port
+    , const std::string &user_agent
     , bool is_rpc = true
     , cryptonote::core_rpc_server* rpc_server = NULL
     );

src/daemon/daemon.cpp

@@ -124,7 +124,7 @@ bool t_daemon::run(bool interactive)
 
     if (interactive)
     {
-      rpc_commands = new daemonize::t_command_server(0, 0, false, mp_internals->rpc.get_server());
+      rpc_commands = new daemonize::t_command_server(0, 0, "", false, mp_internals->rpc.get_server());
       rpc_commands->start_handling(std::bind(&daemonize::t_daemon::stop_p2p, this));
     }
 

src/daemon/main.cpp

@@ -208,6 +208,7 @@ int main(int argc, char const * argv[])
         {
           rpc_port_str = command_line::get_arg(vm, cryptonote::core_rpc_server::arg_testnet_rpc_bind_port);
         }
+        auto user_agent = command_line::get_arg(vm, cryptonote::core_rpc_server::arg_user_agent);
 
         uint32_t rpc_ip;
         uint16_t rpc_port;
@@ -222,7 +223,7 @@ int main(int argc, char const * argv[])
           return 1;
         }
 
-        daemonize::t_command_server rpc_commands{rpc_ip, rpc_port};
+        daemonize::t_command_server rpc_commands{rpc_ip, rpc_port, user_agent};
         if (rpc_commands.process_command_vec(command))
         {
           return 0;

src/daemon/rpc_command_executor.cpp

@@ -92,6 +92,7 @@ namespace {
 t_rpc_command_executor::t_rpc_command_executor(
     uint32_t ip
   , uint16_t port
+  , const std::string &user_agent
   , bool is_rpc
   , cryptonote::core_rpc_server* rpc_server
   )

src/daemon/rpc_command_executor.h

@@ -57,6 +57,7 @@ public:
   t_rpc_command_executor(
       uint32_t ip
     , uint16_t port
+    , const std::string &user_agent
     , bool is_rpc = true
     , cryptonote::core_rpc_server* rpc_server = NULL
     );

src/rpc/core_rpc_server.cpp

@@ -54,6 +54,7 @@ namespace cryptonote
     command_line::add_arg(desc, arg_rpc_bind_port);
     command_line::add_arg(desc, arg_testnet_rpc_bind_port);
     command_line::add_arg(desc, arg_restricted_rpc);
+    command_line::add_arg(desc, arg_user_agent);
   }
   //------------------------------------------------------------------------------------------------------------------------------
   core_rpc_server::core_rpc_server(
@@ -81,11 +82,12 @@ namespace cryptonote
     )
   {
     m_testnet = command_line::get_arg(vm, command_line::arg_testnet_on);
+    std::string m_user_agent = command_line::get_arg(vm, command_line::arg_user_agent);
 
     m_net_server.set_threads_prefix("RPC");
     bool r = handle_command_line(vm);
     CHECK_AND_ASSERT_MES(r, false, "Failed to process command line in core_rpc_server");
-    return epee::http_server_impl_base<core_rpc_server, connection_context>::init(m_port, m_bind_ip);
+    return epee::http_server_impl_base<core_rpc_server, connection_context>::init(m_port, m_bind_ip, m_user_agent);
   }
   //------------------------------------------------------------------------------------------------------------------------------
   bool core_rpc_server::check_core_busy()
@@ -1277,4 +1279,10 @@ namespace cryptonote
     , false
     };
 
+  const command_line::arg_descriptor<std::string> core_rpc_server::arg_user_agent = {
+      "user-agent"
+    , "Restrict RPC to clients using this user agent"
+    , ""
+    };
+
 }  // namespace cryptonote

src/rpc/core_rpc_server.h

@@ -56,6 +56,7 @@ namespace cryptonote
     static const command_line::arg_descriptor<std::string> arg_rpc_bind_port;
     static const command_line::arg_descriptor<std::string> arg_testnet_rpc_bind_port;
     static const command_line::arg_descriptor<bool> arg_restricted_rpc;
+    static const command_line::arg_descriptor<std::string> arg_user_agent;
 
     typedef epee::net_utils::connection_context_base connection_context;
 

src/wallet/wallet_rpc_server.cpp

@@ -45,11 +45,13 @@ namespace tools
   //-----------------------------------------------------------------------------------
   const command_line::arg_descriptor<std::string> wallet_rpc_server::arg_rpc_bind_port = {"rpc-bind-port", "Starts wallet as rpc server for wallet operations, sets bind port for server", "", true};
   const command_line::arg_descriptor<std::string> wallet_rpc_server::arg_rpc_bind_ip = {"rpc-bind-ip", "Specify ip to bind rpc server", "127.0.0.1"};
+  const command_line::arg_descriptor<std::string> wallet_rpc_server::arg_user_agent = {"user-agent", "Restrict RPC to clients using this user agent", ""};
 
   void wallet_rpc_server::init_options(boost::program_options::options_description& desc)
   {
     command_line::add_arg(desc, arg_rpc_bind_ip);
     command_line::add_arg(desc, arg_rpc_bind_port);
+    command_line::add_arg(desc, arg_user_agent);
   }
   //------------------------------------------------------------------------------------------------------------------------------
   wallet_rpc_server::wallet_rpc_server(wallet2& w):m_wallet(w)
@@ -83,6 +85,7 @@ namespace tools
   {
     m_bind_ip = command_line::get_arg(vm, arg_rpc_bind_ip);
     m_port = command_line::get_arg(vm, arg_rpc_bind_port);
+    m_user_agent = command_line::get_arg(vm, arg_user_agent);
     return true;
   }
   //------------------------------------------------------------------------------------------------------------------------------
@@ -91,7 +94,7 @@ namespace tools
     m_net_server.set_threads_prefix("RPC");
     bool r = handle_command_line(vm);
     CHECK_AND_ASSERT_MES(r, false, "Failed to process command line in core_rpc_server");
-    return epee::http_server_impl_base<wallet_rpc_server, connection_context>::init(m_port, m_bind_ip);
+    return epee::http_server_impl_base<wallet_rpc_server, connection_context>::init(m_port, m_bind_ip, m_user_agent);
   }
   //------------------------------------------------------------------------------------------------------------------------------
   bool wallet_rpc_server::on_getbalance(const wallet_rpc::COMMAND_RPC_GET_BALANCE::request& req, wallet_rpc::COMMAND_RPC_GET_BALANCE::response& res, epee::json_rpc::error& er)

src/wallet/wallet_rpc_server.h

@@ -50,6 +50,7 @@ namespace tools
 
     const static command_line::arg_descriptor<std::string> arg_rpc_bind_port;
     const static command_line::arg_descriptor<std::string> arg_rpc_bind_ip;
+    const static command_line::arg_descriptor<std::string> arg_user_agent;
 
 
     static void init_options(boost::program_options::options_description& desc);
@@ -120,6 +121,7 @@ namespace tools
       wallet2& m_wallet;
       std::string m_port;
       std::string m_bind_ip;
+      std::string m_user_agent;
       std::atomic<bool> m_stop;
   };
 }