ssl: Add gracefullness to dtls code

Also make tls code a little more direct for easier uderstanding

2 files changed, 70 insertions, 39 deletions

diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 1c55e370cb..073cb4009b 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -444,21 +444,21 @@ init({call, From}, {start, Timeout},
     {Record, State} = next_record(State3),
     next_event(hello, Record, State, Actions);
 init({call, _} = Type, Event, #state{role = server, transport_cb = gen_udp} = State) ->
-    Result = ssl_connection:?FUNCTION_NAME(Type, Event, 
-                                           State#state{flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT},
-                                                       protocol_specific = #{current_cookie_secret => dtls_v1:cookie_secret(), 
-                                                                             previous_cookie_secret => <<>>,
-                                                                             ignored_alerts => 0,
-                                                                             max_ignored_alerts => 10}},
-                                           ?MODULE),
+    Result = gen_handshake(?FUNCTION_NAME, Type, Event, 
+                           State#state{flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT},
+                                       protocol_specific = #{current_cookie_secret => dtls_v1:cookie_secret(), 
+                                                             previous_cookie_secret => <<>>,
+                                                             ignored_alerts => 0,
+                                                             max_ignored_alerts => 10}}),
     erlang:send_after(dtls_v1:cookie_timeout(), self(), new_cookie_secret),
     Result;
 
 init({call, _} = Type, Event, #state{role = server} = State) ->
     %% I.E. DTLS over sctp
-    ssl_connection:?FUNCTION_NAME(Type, Event, State#state{flight_state = reliable}, ?MODULE);
+    gen_handshake(?FUNCTION_NAME, Type, Event, State#state{flight_state = reliable});
 init(Type, Event, State) ->
-    ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE).
+   gen_handshake(?FUNCTION_NAME, Type, Event, State).
+
 %%--------------------------------------------------------------------
 -spec error(gen_statem:event_type(),
 	   {start, timeout()} | term(), #state{}) ->
@@ -469,7 +469,7 @@ error(enter, _, State) ->
 error({call, From}, {start, _Timeout}, {Error, State}) ->
     {stop_and_reply, normal, {reply, From, {error, Error}}, State};
 error({call, _} = Call, Msg, State) ->
-    ssl_connection:?FUNCTION_NAME(Call, Msg, State, ?MODULE);
+    gen_handshake(?FUNCTION_NAME, Call, Msg, State);
 error(_, _, _) ->
      {keep_state_and_data, [postpone]}.
 
@@ -564,11 +564,11 @@ hello(internal, {handshake, {#hello_verify_request{} = Handshake, _}}, State) ->
     %% hello_verify should not be in handshake history
     {next_state, ?FUNCTION_NAME, State, [{next_event, internal, Handshake}]};
 hello(info, Event, State) ->
-    handle_info(Event, ?FUNCTION_NAME, State);
+    gen_info(Event, ?FUNCTION_NAME, State);
 hello(state_timeout, Event, State) ->
     handle_state_timeout(Event, ?FUNCTION_NAME, State);
 hello(Type, Event, State) ->
-    ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec abbreviated(gen_statem:event_type(), term(), #state{}) ->
@@ -578,22 +578,21 @@ abbreviated(enter, _, State0) ->
     {State, Actions} = handle_flight_timer(State0),
     {keep_state, State, Actions}; 
 abbreviated(info, Event, State) ->
-    handle_info(Event, ?FUNCTION_NAME, State);
+    gen_info(Event, ?FUNCTION_NAME, State);
 abbreviated(internal = Type, 
 	    #change_cipher_spec{type = <<1>>} = Event, 
 	    #state{connection_states = ConnectionStates0} = State) ->
     ConnectionStates1 = dtls_record:save_current_connection_state(ConnectionStates0, read),
     ConnectionStates = dtls_record:next_epoch(ConnectionStates1, read),
-    ssl_connection:?FUNCTION_NAME(Type, Event, State#state{connection_states = ConnectionStates}, ?MODULE);
+    gen_handshake(?FUNCTION_NAME, Type, Event, State#state{connection_states = ConnectionStates});
 abbreviated(internal = Type, #finished{} = Event, #state{connection_states = ConnectionStates} = State) ->
-    ssl_connection:?FUNCTION_NAME(Type, Event, 
-                                  prepare_flight(State#state{connection_states = ConnectionStates,
-                                                             flight_state = connection}), ?MODULE);
+    gen_handshake(?FUNCTION_NAME, Type, Event, 
+                  prepare_flight(State#state{connection_states = ConnectionStates,
+                                             flight_state = connection}));
 abbreviated(state_timeout, Event, State) ->
     handle_state_timeout(Event, ?FUNCTION_NAME, State);
 abbreviated(Type, Event, State) ->
-    ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE).
-
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 %%--------------------------------------------------------------------
 -spec certify(gen_statem:event_type(), term(), #state{}) ->
 		     gen_statem:state_function_result().
@@ -602,13 +601,13 @@ certify(enter, _, State0) ->
     {State, Actions} = handle_flight_timer(State0),
     {keep_state, State, Actions}; 
 certify(info, Event, State) ->
-    handle_info(Event, ?FUNCTION_NAME, State);
+    gen_info(Event, ?FUNCTION_NAME, State);
 certify(internal = Type, #server_hello_done{} = Event, State) ->
     ssl_connection:certify(Type, Event, prepare_flight(State), ?MODULE);
 certify(state_timeout, Event, State) ->
     handle_state_timeout(Event, ?FUNCTION_NAME, State);
 certify(Type, Event, State) ->
-    ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec cipher(gen_statem:event_type(), term(), #state{}) ->
@@ -618,7 +617,7 @@ cipher(enter, _, State0) ->
     {State, Actions} = handle_flight_timer(State0),
     {keep_state, State, Actions}; 
 cipher(info, Event, State) ->
-    handle_info(Event, ?FUNCTION_NAME, State);
+    gen_info(Event, ?FUNCTION_NAME, State);
 cipher(internal = Type, #change_cipher_spec{type = <<1>>} = Event,  
        #state{connection_states = ConnectionStates0} = State) ->
     ConnectionStates1 = dtls_record:save_current_connection_state(ConnectionStates0, read),
@@ -642,7 +641,7 @@ cipher(Type, Event, State) ->
 connection(enter, _, State) ->
     {keep_state, State};     
 connection(info, Event, State) ->
-    handle_info(Event, ?FUNCTION_NAME, State);
+    gen_info(Event, ?FUNCTION_NAME, State);
 connection(internal, #hello_request{}, #state{host = Host, port = Port,
                                               session = #session{own_certificate = Cert} = Session0,
                                               session_cache = Cache, session_cache_cb = CacheCb,
@@ -905,6 +904,39 @@ encode_change_cipher(#change_cipher_spec{}, Version, Epoch, ConnectionStates) ->
 decode_alerts(Bin) ->
     ssl_alert:decode(Bin).
 
+gen_handshake(StateName, Type, Event, 
+	      #state{negotiated_version = Version} = State) ->
+    try ssl_connection:StateName(Type, Event, State, ?MODULE) of
+	Result ->
+	    Result
+    catch 
+	_:_ ->
+ 	    ssl_connection:handle_own_alert(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, 
+						       malformed_handshake_data),
+					    Version, StateName, State)  
+    end.
+
+gen_info(Event, connection = StateName,  #state{negotiated_version = Version} = State) ->
+    try handle_info(Event, StateName, State) of
+	Result ->
+	    Result
+    catch 
+	_:_ ->
+	    ssl_connection:handle_own_alert(?ALERT_REC(?FATAL, ?INTERNAL_ERROR, 
+						       malformed_data), 
+					    Version, StateName, State)  
+    end;
+
+gen_info(Event, StateName, #state{negotiated_version = Version} = State) ->
+    try handle_info(Event, StateName, State) of
+	Result ->
+	    Result
+    catch 
+        _:_ ->
+	    ssl_connection:handle_own_alert(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, 
+						       malformed_handshake_data), 
+					    Version, StateName, State)  
+    end.
 unprocessed_events(Events) ->
     %% The first handshake event will be processed immediately
     %% as it is entered first in the event queue and
diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index a4cdce3902..3137643aa9 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -431,7 +431,7 @@ init({call, From}, {start, Timeout},
     {Record, State} = next_record(State1),
     next_event(hello, Record, State);
 init(Type, Event, State) ->
-    gen_handshake(ssl_connection, ?FUNCTION_NAME, Type, Event, State).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
  
 %%--------------------------------------------------------------------
 -spec error(gen_statem:event_type(),
@@ -442,7 +442,7 @@ init(Type, Event, State) ->
 error({call, From}, {start, _Timeout}, {Error, State}) ->
     {stop_and_reply, normal, {reply, From, {error, Error}}, State};
 error({call, _} = Call, Msg, State) ->
-    ssl_connection:?FUNCTION_NAME(Call, Msg, State, ?MODULE);
+    gen_handshake(?FUNCTION_NAME, Call, Msg, State);
 error(_, _, _) ->
      {keep_state_and_data, [postpone]}.
  
@@ -472,14 +472,13 @@ hello(internal, #client_hello{client_version = ClientVersion} = Hello,
 			   undefined -> CurrentProtocol;
 			   _ -> Protocol0
 		       end,
-	    
-	    gen_handshake(ssl_connection, hello, internal, {common_client_hello, Type, ServerHelloExt},
-				 State#state{connection_states  = ConnectionStates,
-					     negotiated_version = Version,
-                                             client_hello_version = ClientVersion,
-					     hashsign_algorithm = HashSign,
-					     session = Session,
-					     negotiated_protocol = Protocol})
+            gen_handshake(?FUNCTION_NAME, internal, {common_client_hello, Type, ServerHelloExt},
+                          State#state{connection_states  = ConnectionStates,
+                                      negotiated_version = Version,
+                                      hashsign_algorithm = HashSign,
+                                      client_hello_version = ClientVersion,
+                                      session = Session,
+                                      negotiated_protocol = Protocol})
     end;
 hello(internal, #server_hello{} = Hello,
       #state{connection_states = ConnectionStates0,
@@ -497,7 +496,7 @@ hello(internal, #server_hello{} = Hello,
 hello(info, Event, State) ->
     gen_info(Event, ?FUNCTION_NAME, State);
 hello(Type, Event, State) ->
-    gen_handshake(ssl_connection, ?FUNCTION_NAME, Type, Event, State).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec abbreviated(gen_statem:event_type(), term(), #state{}) ->
@@ -506,7 +505,7 @@ hello(Type, Event, State) ->
 abbreviated(info, Event, State) ->
     gen_info(Event, ?FUNCTION_NAME, State);
 abbreviated(Type, Event, State) ->
-    gen_handshake(ssl_connection, ?FUNCTION_NAME, Type, Event, State).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec certify(gen_statem:event_type(), term(), #state{}) ->
@@ -515,7 +514,7 @@ abbreviated(Type, Event, State) ->
 certify(info, Event, State) ->
     gen_info(Event, ?FUNCTION_NAME, State);
 certify(Type, Event, State) ->
-    gen_handshake(ssl_connection, ?FUNCTION_NAME, Type, Event, State).
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec cipher(gen_statem:event_type(), term(), #state{}) ->
@@ -524,7 +523,7 @@ certify(Type, Event, State) ->
 cipher(info, Event, State) ->
     gen_info(Event, ?FUNCTION_NAME, State);
 cipher(Type, Event, State) ->
-     gen_handshake(ssl_connection, ?FUNCTION_NAME, Type, Event, State).
+     gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
 %%--------------------------------------------------------------------
 -spec connection(gen_statem:event_type(),  
@@ -715,9 +714,9 @@ encode_change_cipher(#change_cipher_spec{}, Version, ConnectionStates) ->
 decode_alerts(Bin) ->
     ssl_alert:decode(Bin).
 
-gen_handshake(GenConnection, StateName, Type, Event, 
+gen_handshake(StateName, Type, Event, 
 	      #state{negotiated_version = Version} = State) ->
-    try GenConnection:StateName(Type, Event, State, ?MODULE) of
+    try ssl_connection:StateName(Type, Event, State, ?MODULE) of
 	Result ->
 	    Result
     catch