ssl: Implement DTLS state machine

Beta DTLS, not production ready. Only very basically tested, and
not everything in the SPEC is implemented and some things
are hard coded that should not be, so this implementation can not be consider
secure.

Refactor "TLS connection state" and socket handling, to facilitate
DTLS implementation.

Create dtls "listner" (multiplexor) process that spawns
DTLS connection process handlers.

Handle DTLS fragmentation.

Framework for handling retransmissions.

Replay Detection is not implemented yet.

Alerts currently always handled as in TLS.

1 files changed, 29 insertions, 12 deletions

diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index 932bb139c1..32991d3079 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -45,6 +45,8 @@
 %% Setup
 -export([start_fsm/8, start_link/7, init/1]).
 
+-export([encode_data/3, encode_alert/3]).
+
 %% State transition handling	 
 -export([next_record/1, next_event/3]).
 
@@ -57,7 +59,7 @@
 -export([send_alert/2, close/5]).
 
 %% Data handling
--export([passive_receive/2, next_record_if_active/1, handle_common_event/4]).
+-export([passive_receive/2, next_record_if_active/1, handle_common_event/4, send/3]).
 
 %% gen_statem state functions
 -export([init/3, error/3, downgrade/3, %% Initiation and take down states
@@ -114,7 +116,7 @@ queue_handshake(Handshake, #state{negotiated_version = Version,
 send_handshake_flight(#state{socket = Socket,
 			     transport_cb = Transport,
 			     flight_buffer = Flight} = State0) ->
-    Transport:send(Socket, Flight),
+    send(Transport, Socket, Flight),
     State0#state{flight_buffer = []}.
 
 queue_change_cipher(Msg, #state{negotiated_version = Version,
@@ -130,8 +132,8 @@ send_alert(Alert, #state{negotiated_version = Version,
 			 transport_cb = Transport,
 			 connection_states = ConnectionStates0} = State0) ->
     {BinMsg, ConnectionStates} =
-	ssl_alert:encode(Alert, Version, ConnectionStates0),
-    Transport:send(Socket, BinMsg),
+	encode_alert(Alert, Version, ConnectionStates0),
+    send(Transport, Socket, BinMsg),
     State0#state{connection_states = ConnectionStates}.
 
 reinit_handshake_data(State) ->
@@ -149,6 +151,18 @@ select_sni_extension(#client_hello{extensions = HelloExtensions}) ->
 select_sni_extension(_) ->
     undefined.
 
+encode_data(Data, Version, ConnectionStates0)->
+    tls_record:encode_data(Data, Version, ConnectionStates0).
+
+%%--------------------------------------------------------------------
+-spec encode_alert(#alert{}, ssl_record:ssl_version(), ssl_record:connection_states()) -> 
+		    {iolist(), ssl_record:connection_states()}.
+%%
+%% Description: Encodes an alert
+%%--------------------------------------------------------------------
+encode_alert(#alert{} = Alert, Version, ConnectionStates) ->
+    tls_record:encode_alert_record(Alert, Version, ConnectionStates).
+
 %%====================================================================
 %% tls_connection_sup API
 %%====================================================================
@@ -205,7 +219,7 @@ init({call, From}, {start, Timeout},
     Handshake0 = ssl_handshake:init_handshake_history(),
     {BinMsg, ConnectionStates, Handshake} =
         encode_handshake(Hello,  HelloVersion, ConnectionStates0, Handshake0, V2HComp),
-    Transport:send(Socket, BinMsg),
+    send(Transport, Socket, BinMsg),
     State1 = State0#state{connection_states = ConnectionStates,
 			  negotiated_version = Version, %% Requested version
 			  session =
@@ -450,6 +464,9 @@ handle_common_event(internal, #ssl_tls{type = ?ALERT, fragment = EncAlerts}, Sta
 handle_common_event(internal, #ssl_tls{type = _Unknown}, StateName, State) ->
     {next_state, StateName, State}.
 
+send(Transport, Socket, Data) ->
+   tls_socket:send(Transport, Socket, Data).
+
 %%--------------------------------------------------------------------
 %% gen_statem callbacks
 %%--------------------------------------------------------------------
@@ -476,11 +493,11 @@ encode_handshake(Handshake, Version, ConnectionStates0, Hist0, V2HComp) ->
     Frag = tls_handshake:encode_handshake(Handshake, Version),
     Hist = ssl_handshake:update_handshake_history(Hist0, Frag, V2HComp),
     {Encoded, ConnectionStates} =
-        ssl_record:encode_handshake(Frag, Version, ConnectionStates0),
+        tls_record:encode_handshake(Frag, Version, ConnectionStates0),
     {Encoded, ConnectionStates, Hist}.
 
 encode_change_cipher(#change_cipher_spec{}, Version, ConnectionStates) ->
-    ssl_record:encode_change_cipher_spec(Version, ConnectionStates).
+    tls_record:encode_change_cipher_spec(Version, ConnectionStates).
 
 decode_alerts(Bin) ->
     ssl_alert:decode(Bin).
@@ -553,7 +570,7 @@ next_record(#state{protocol_buffers =
 next_record(#state{protocol_buffers = #protocol_buffers{tls_packets = [], tls_cipher_texts = []},
 		   socket = Socket,
 		   transport_cb = Transport} = State) ->
-    ssl_socket:setopts(Transport, Socket, [{active,once}]),
+    tls_socket:setopts(Transport, Socket, [{active,once}]),
     {no_record, State};
 next_record(State) ->
     {no_record, State}.
@@ -622,8 +639,8 @@ renegotiate(#state{role = server,
     Frag = tls_handshake:encode_handshake(HelloRequest, Version),
     Hs0 = ssl_handshake:init_handshake_history(),
     {BinMsg, ConnectionStates} = 
-	ssl_record:encode_handshake(Frag, Version, ConnectionStates0),
-    Transport:send(Socket, BinMsg),
+	tls_record:encode_handshake(Frag, Version, ConnectionStates0),
+    send(Transport, Socket, BinMsg),
     State1 = State0#state{connection_states = 
 			     ConnectionStates,
 			 tls_handshake_history = Hs0},
@@ -642,7 +659,7 @@ handle_alerts([Alert | Alerts], {next_state, StateName, State, _Actions}) ->
 
 %% User closes or recursive call!
 close({close, Timeout}, Socket, Transport = gen_tcp, _,_) ->
-    ssl_socket:setopts(Transport, Socket, [{active, false}]),
+    tls_socket:setopts(Transport, Socket, [{active, false}]),
     Transport:shutdown(Socket, write),
     _ = Transport:recv(Socket, 0, Timeout),
     ok;
@@ -684,7 +701,7 @@ gen_handshake(GenConnection, StateName, Type, Event,
 	    Result
     catch 
 	_:_ ->
-	    ssl_connection:handle_own_alert(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, 
+ 	    ssl_connection:handle_own_alert(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, 
 						       malformed_handshake_data),
 					    Version, StateName, State)  
     end.