ssl: simplyfy code using gen_statem

2 files changed, 45 insertions, 70 deletions

diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl
index 22d107ff9c..b45c5c8fc6 100644
--- a/lib/ssl/src/ssl_connection.erl
+++ b/lib/ssl/src/ssl_connection.erl
@@ -786,12 +786,24 @@ downgrade(Type, Event, State, Connection) ->
 %% Event handling functions called by state functions to handle
 %% common or unexpected events for the state.
 %%--------------------------------------------------------------------
+handle_common_event(internal, {handshake, {#hello_request{} = Handshake, _}}, connection = StateName,  
+		    #state{role = client} = State, _) ->
+    %% Should not be included in handshake history
+    {next_state, StateName, State#state{renegotiation = {true, peer}}, [{next_event, internal, Handshake}]};
+handle_common_event(internal, {handshake, {#hello_request{}, _}}, StateName, #state{role = client}, _) 
+  when StateName =/= connection ->
+    {keep_state_and_data};
+handle_common_event(internal, {handshake, {Handshake, Raw}}, StateName, 
+		    #state{tls_handshake_history = Hs0} = State0, Connection) ->
+    %% This function handles client SNI hello extension when Handshake is
+    %% a client_hello, which needs to be determined by the connection callback.
+    %% In other cases this is a noop
+    State = Connection:handle_sni_extension(Handshake, State0),
+    HsHist = ssl_handshake:update_handshake_history(Hs0, Raw),
+    {next_state, StateName, State#state{tls_handshake_history = HsHist}, 
+     [{next_event, internal, Handshake}]};
 handle_common_event(internal, {tls_record, TLSRecord}, StateName, State, Connection) -> 
     Connection:handle_common_event(internal, TLSRecord, StateName, State);
-handle_common_event(internal, #hello_request{}, StateName, #state{role = client} = State0, Connection)
-  when StateName =:= connection ->
-    {Record, State} = Connection:next_record(State0),
-    Connection:next_event(StateName, Record, State);
 handle_common_event(timeout, hibernate, _, _, _) ->
     {keep_state_and_data, [hibernate]};
 handle_common_event(internal, {application_data, Data}, StateName, State0, Connection) ->
diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index 91903b4a1f..56e516bce2 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -50,7 +50,7 @@
 
 %% Handshake handling
 -export([renegotiate/2, send_handshake/2, send_change_cipher/2,
-	reinit_handshake_data/1]).
+	reinit_handshake_data/1, handle_sni_extension/2]).
 
 %% Alert and close handling
 -export([send_alert/2, handle_own_alert/4, handle_close_alert/3,
@@ -228,16 +228,16 @@ error(_, _, _) ->
 		   gen_statem:state_function_result().
 %%--------------------------------------------------------------------
 hello(internal, #client_hello{client_version = ClientVersion,
-			      extensions = #hello_extensions{ec_point_formats = EcPointFormats,
-							     elliptic_curves = EllipticCurves}} = Hello,
-      State = #state{connection_states = ConnectionStates0,
-		     port = Port, session = #session{own_certificate = Cert} = Session0,
-		     renegotiation = {Renegotiation, _},
-		     session_cache = Cache,
-		     session_cache_cb = CacheCb,
-		     negotiated_protocol = CurrentProtocol,
-		     key_algorithm = KeyExAlg,
-		     ssl_options = SslOpts}) ->
+			       extensions = #hello_extensions{ec_point_formats = EcPointFormats,
+							      elliptic_curves = EllipticCurves}} = Hello,
+      #state{connection_states = ConnectionStates0,
+	     port = Port, session = #session{own_certificate = Cert} = Session0,
+	     renegotiation = {Renegotiation, _},
+	     session_cache = Cache,
+	     session_cache_cb = CacheCb,
+	     negotiated_protocol = CurrentProtocol,
+	     key_algorithm = KeyExAlg,
+	     ssl_options = SslOpts} = State) ->
 
     case tls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb,
 					      ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of
@@ -311,7 +311,7 @@ cipher(Type, Event, State) ->
 connection(info, Event, State) ->
     handle_info(Event, connection, State);
 connection(internal, #hello_request{},
-	   #state{host = Host, port = Port,
+	   #state{role = client, host = Host, port = Port,
 		  session = #session{own_certificate = Cert} = Session0,
 		  session_cache = Cache, session_cache_cb = CacheCb,
 		  ssl_options = SslOpts,
@@ -326,14 +326,16 @@ connection(internal, #hello_request{},
 						  = Hello#client_hello.session_id}}),
     next_event(hello, Record, State);
 connection(internal, #client_hello{} = Hello, 
-	   #state{role = server, allow_renegotiate = true} = State) ->
+	   #state{role = server, allow_renegotiate = true} = State0) ->
     %% Mitigate Computational DoS attack
     %% http://www.educatedguesswork.org/2011/10/ssltls_and_computational_dos.html
     %% http://www.thc.org/thc-ssl-dos/ Rather than disabling client
     %% initiated renegotiation we will disallow many client initiated
     %% renegotiations immediately after each other.
     erlang:send_after(?WAIT_TO_ALLOW_RENEGOTIATION, self(), allow_renegotiate),
-    {next_state, hello, State#state{allow_renegotiate = false}, [{next_event, internal, Hello}]};
+    {Record, State} = next_record(State0#state{allow_renegotiate = false,
+					       renegotiation = {true, peer}}),
+    next_event(hello, Record, State,  [{next_event, internal, Hello}]);
 connection(internal, #client_hello{}, 
 	   #state{role = server, allow_renegotiate = false} = State0) ->
     Alert = ?ALERT_REC(?WARNING, ?NO_RENEGOTIATION),
@@ -398,39 +400,12 @@ handle_common_event(internal,  #ssl_tls{type = ?HANDSHAKE, fragment = Data},
 		    StateName, #state{protocol_buffers =
 					  #protocol_buffers{tls_handshake_buffer = Buf0} = Buffers,
 				      negotiated_version = Version} = State0) ->
-    
-    Handle = 
-   	fun({#hello_request{} = Packet, _}, {connection, HState}) ->
-   		%% This message should not be included in handshake
-   		%% message hashes. Starts new handshake (renegotiation)
-		Hs0 = ssl_handshake:init_handshake_history(),
-		{HState#state{tls_handshake_history = Hs0,
-			      renegotiation = {true, peer}}, 
-		 {next_event, internal, Packet}};
-   	   ({#hello_request{}, _}, {next_state, _SName, HState}) ->
-   		%% This message should not be included in handshake
-   		%% message hashes. Already in negotiation so it will be ignored!
-		{HState, []};
-	   ({#client_hello{} = Packet, Raw}, {connection, HState0}) ->
-		HState = handle_sni_extension(Packet, HState0),
-		Version = Packet#client_hello.client_version,
-		Hs0 = ssl_handshake:init_handshake_history(),
-		Hs1 = ssl_handshake:update_handshake_history(Hs0, Raw),
-		{HState#state{tls_handshake_history = Hs1,
-			      renegotiation = {true, peer}}, 
-		 {next_event, internal, Packet}};
-	   
-	   ({Packet, Raw}, {_SName, HState0 = #state{tls_handshake_history=Hs0}}) ->
-		HState = handle_sni_extension(Packet, HState0),
-		Hs1 = ssl_handshake:update_handshake_history(Hs0, Raw),
-		{HState#state{tls_handshake_history=Hs1}, {next_event, internal, Packet}}
-   	end,
-    try
+        try
 	{Packets, Buf} = tls_handshake:get_tls_handshake(Version,Data,Buf0),
-	State1 = State0#state{protocol_buffers =
-				  Buffers#protocol_buffers{tls_packets = Packets,
-							   tls_handshake_buffer = Buf}},
-	{State, Events} = tls_handshake_events(Handle, StateName, State1, []),
+	State =
+	    State0#state{protocol_buffers =
+			     Buffers#protocol_buffers{tls_handshake_buffer = Buf}},
+	Events = tls_handshake_events(Packets),
 	case StateName of
 	    connection ->
 		ssl_connection:hibernate_after(StateName, State, Events);
@@ -779,24 +754,12 @@ send_or_reply(_, Pid, _From, Data) ->
 send_user(Pid, Msg) ->
     Pid ! Msg.
 
-tls_handshake_events(Handle, StateName,
-  		     #state{protocol_buffers =
-  				#protocol_buffers{tls_packets = [Packet]} = Buffers} = State0, Acc) ->
-    {State, Event} = Handle(Packet, {StateName, 
-				     State0#state{protocol_buffers =
-						      Buffers#protocol_buffers{tls_packets = []}}}),
-    {State, lists:reverse([Event |Acc])};
-tls_handshake_events(Handle, StateName,
- 		     #state{protocol_buffers =
- 				#protocol_buffers{tls_packets = 
-						      [Packet | Packets]} = Buffers} = State0, Acc) ->    
-    {State, Event} = Handle(Packet, {StateName, State0#state{protocol_buffers =
-								 Buffers#protocol_buffers{tls_packets =
-											      Packets}}}),
-    tls_handshake_events(Handle, StateName, State, [Event | Acc]);
-
-tls_handshake_events(_Handle, _, #state{}, _) ->
-     throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE)).
+tls_handshake_events([]) ->
+    throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, malformed_handshake));
+tls_handshake_events(Packets) ->
+    lists:map(fun(Packet) ->
+		      {next_event, internal, {handshake, Packet}}
+	      end, Packets).
 
 write_application_data(Data0, From, 
 		       #state{socket = Socket,
@@ -1065,5 +1028,5 @@ handle_sni_extension(#client_hello{extensions = HelloExtensions}, State0) ->
 		     }
 	    end
     end;
-handle_sni_extension(_, State0) ->
-    State0.
+handle_sni_extension(_, State) ->
+    State.