diff options
Diffstat (limited to 'lib/ssl/src/dtls_connection.erl')
| -rw-r--r-- | lib/ssl/src/dtls_connection.erl | 606 |
1 files changed, 365 insertions, 241 deletions
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl index 4f1f050e4b..070a90d481 100644 --- a/lib/ssl/src/dtls_connection.erl +++ b/lib/ssl/src/dtls_connection.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2013-2015. All Rights Reserved. +%% Copyright Ericsson AB 2013-2016. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -48,12 +48,12 @@ select_sni_extension/1]). %% Alert and close handling --export([send_alert/2, close/5]). +-export([encode_alert/3,send_alert/2, close/5]). %% Data handling --export([passive_receive/2, next_record_if_active/1, handle_common_event/4 - ]). +-export([encode_data/3, 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 @@ -93,61 +93,120 @@ start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = true},_, Tracker} = Error end. -send_handshake(Handshake, State) -> - send_handshake_flight(queue_handshake(Handshake, State)). +send_handshake(Handshake, #state{connection_states = ConnectionStates} = States) -> + #{epoch := Epoch} = ssl_record:current_connection_state(ConnectionStates, write), + send_handshake_flight(queue_handshake(Handshake, States), Epoch). + +queue_handshake(Handshake0, #state{tls_handshake_history = Hist0, + negotiated_version = Version, + flight_buffer = #{handshakes := HsBuffer0, + change_cipher_spec := undefined, + next_sequence := Seq} = Flight0} = State) -> + Handshake = dtls_handshake:encode_handshake(Handshake0, Version, Seq), + Hist = update_handshake_history(Handshake0, Handshake, Hist0), + State#state{flight_buffer = Flight0#{handshakes => [Handshake | HsBuffer0], + next_sequence => Seq +1}, + tls_handshake_history = Hist}; + +queue_handshake(Handshake0, #state{tls_handshake_history = Hist0, + negotiated_version = Version, + flight_buffer = #{handshakes_after_change_cipher_spec := Buffer0, + next_sequence := Seq} = Flight0} = State) -> + Handshake = dtls_handshake:encode_handshake(Handshake0, Version, Seq), + Hist = update_handshake_history(Handshake0, Handshake, Hist0), + State#state{flight_buffer = Flight0#{handshakes_after_change_cipher_spec => [Handshake | Buffer0], + next_sequence => Seq +1}, + tls_handshake_history = Hist}. -queue_flight_buffer(Msg, #state{negotiated_version = Version, - connection_states = ConnectionStates, - flight_buffer = Flight} = State) -> - ConnectionState = - ssl_record:current_connection_state(ConnectionStates, write), - Epoch = maps:get(epoch, ConnectionState), - State#state{flight_buffer = Flight ++ [{Version, Epoch, Msg}]}. - -queue_handshake(Handshake, #state{negotiated_version = Version, - tls_handshake_history = Hist0, - connection_states = ConnectionStates0} = State0) -> - {Frag, ConnectionStates, Hist} = - encode_handshake(Handshake, Version, ConnectionStates0, Hist0), - queue_flight_buffer(Frag, State0#state{connection_states = ConnectionStates, - tls_handshake_history = Hist}). send_handshake_flight(#state{socket = Socket, transport_cb = Transport, - flight_buffer = Flight, - connection_states = ConnectionStates0} = State0) -> - + flight_buffer = #{handshakes := Flight, + change_cipher_spec := undefined}, + negotiated_version = Version, + connection_states = ConnectionStates0} = State0, Epoch) -> + %% TODO remove hardcoded Max size {Encoded, ConnectionStates} = - encode_handshake_flight(Flight, ConnectionStates0), + encode_handshake_flight(lists:reverse(Flight), Version, 1400, Epoch, ConnectionStates0), + send(Transport, Socket, Encoded), + start_flight(State0#state{connection_states = ConnectionStates}); + +send_handshake_flight(#state{socket = Socket, + transport_cb = Transport, + flight_buffer = #{handshakes := [_|_] = Flight0, + change_cipher_spec := ChangeCipher, + handshakes_after_change_cipher_spec := []}, + negotiated_version = Version, + connection_states = ConnectionStates0} = State0, Epoch) -> + {HsBefore, ConnectionStates1} = + encode_handshake_flight(lists:reverse(Flight0), Version, 1400, Epoch, ConnectionStates0), + {EncChangeCipher, ConnectionStates} = encode_change_cipher(ChangeCipher, Version, Epoch, ConnectionStates1), + + send(Transport, Socket, [HsBefore, EncChangeCipher]), + start_flight(State0#state{connection_states = ConnectionStates}); - Transport:send(Socket, Encoded), - State0#state{flight_buffer = [], connection_states = ConnectionStates}. +send_handshake_flight(#state{socket = Socket, + transport_cb = Transport, + flight_buffer = #{handshakes := [_|_] = Flight0, + change_cipher_spec := ChangeCipher, + handshakes_after_change_cipher_spec := Flight1}, + negotiated_version = Version, + connection_states = ConnectionStates0} = State0, Epoch) -> + {HsBefore, ConnectionStates1} = + encode_handshake_flight(lists:reverse(Flight0), Version, 1400, Epoch-1, ConnectionStates0), + {EncChangeCipher, ConnectionStates2} = + encode_change_cipher(ChangeCipher, Version, Epoch-1, ConnectionStates1), + {HsAfter, ConnectionStates} = + encode_handshake_flight(lists:reverse(Flight1), Version, 1400, Epoch, ConnectionStates2), + send(Transport, Socket, [HsBefore, EncChangeCipher, HsAfter]), + start_flight(State0#state{connection_states = ConnectionStates}); -queue_change_cipher(Msg, State) -> - queue_flight_buffer(Msg, State). +send_handshake_flight(#state{socket = Socket, + transport_cb = Transport, + flight_buffer = #{handshakes := [], + change_cipher_spec := ChangeCipher, + handshakes_after_change_cipher_spec := Flight1}, + negotiated_version = Version, + connection_states = ConnectionStates0} = State0, Epoch) -> + {EncChangeCipher, ConnectionStates1} = + encode_change_cipher(ChangeCipher, Version, Epoch-1, ConnectionStates0), + {HsAfter, ConnectionStates} = + encode_handshake_flight(lists:reverse(Flight1), Version, 1400, Epoch, ConnectionStates1), + send(Transport, Socket, [EncChangeCipher, HsAfter]), + start_flight(State0#state{connection_states = ConnectionStates}). + +queue_change_cipher(ChangeCipher, #state{flight_buffer = Flight, + connection_states = ConnectionStates0} = State) -> + ConnectionStates = + dtls_record:next_epoch(ConnectionStates0, write), + State#state{flight_buffer = Flight#{change_cipher_spec => ChangeCipher}, + connection_states = ConnectionStates}. send_alert(Alert, #state{negotiated_version = Version, socket = Socket, 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}. close(downgrade, _,_,_,_) -> ok; %% Other close(_, Socket, Transport, _,_) -> - Transport:close(Socket). + dtls_socket:close(Transport,Socket). reinit_handshake_data(#state{protocol_buffers = Buffers} = State) -> State#state{premaster_secret = undefined, public_key_info = undefined, tls_handshake_history = ssl_handshake:init_handshake_history(), protocol_buffers = - Buffers#protocol_buffers{dtls_fragment_state = - dtls_handshake:dtls_handshake_new_flight(0)}}. + Buffers#protocol_buffers{ + dtls_handshake_next_seq = 0, + dtls_handshake_next_fragments = [], + dtls_handshake_later_fragments = [] + }}. select_sni_extension(#client_hello{extensions = HelloExtensions}) -> HelloExtensions#hello_extensions.sni; @@ -160,7 +219,7 @@ select_sni_extension(_) -> %%-------------------------------------------------------------------- -spec start_link(atom(), host(), inet:port_number(), port(), list(), pid(), tuple()) -> - {ok, pid()} | ignore | {error, reason()}. + {ok, pid()} | ignore | {error, reason()}. %% %% Description: Creates a gen_fsm process which calls Module:init/1 to %% initialize. To ensure a synchronized start-up procedure, this function @@ -191,7 +250,6 @@ init({call, From}, {start, Timeout}, #state{host = Host, port = Port, role = client, ssl_options = SslOpts, session = #session{own_certificate = Cert} = Session0, - transport_cb = Transport, socket = Socket, connection_states = ConnectionStates0, renegotiation = {Renegotiation, _}, session_cache = Cache, @@ -199,23 +257,26 @@ init({call, From}, {start, Timeout}, } = State0) -> Timer = ssl_connection:start_or_recv_cancel_timer(Timeout, From), Hello = dtls_handshake:client_hello(Host, Port, ConnectionStates0, SslOpts, - Cache, CacheCb, Renegotiation, Cert), - + Cache, CacheCb, Renegotiation, Cert), + Version = Hello#client_hello.client_version, HelloVersion = dtls_record:lowest_protocol_version(SslOpts#ssl_options.versions), - Handshake0 = ssl_handshake:init_handshake_history(), - {BinMsg, ConnectionStates, Handshake} = - encode_handshake(Hello, HelloVersion, ConnectionStates0, Handshake0), - Transport:send(Socket, BinMsg), - State1 = State0#state{connection_states = ConnectionStates, - negotiated_version = Version, %% Requested version + State1 = prepare_flight(State0#state{negotiated_version = Version}), + State2 = send_handshake(Hello, State1#state{negotiated_version = HelloVersion}), + State3 = State2#state{negotiated_version = Version, %% Requested version session = Session0#session{session_id = Hello#client_hello.session_id}, - tls_handshake_history = Handshake, start_or_recv_from = From, timer = Timer}, - {Record, State} = next_record(State1), + {Record, State} = next_record(State3), next_event(hello, Record, State); +init({call, _} = Type, Event, #state{role = server, transport_cb = gen_udp} = State) -> + ssl_connection:init(Type, Event, + State#state{flight_state = {waiting, undefined, ?INITIAL_RETRANSMIT_TIMEOUT}}, + ?MODULE); +init({call, _} = Type, Event, #state{role = server} = State) -> + %% I.E. DTLS over sctp + ssl_connection:init(Type, Event, State#state{flight_state = reliable}, ?MODULE); init(Type, Event, State) -> ssl_connection:init(Type, Event, State, ?MODULE). @@ -232,34 +293,53 @@ error(_, _, _) -> #state{}) -> gen_statem:state_function_result(). %%-------------------------------------------------------------------- -hello(internal, #client_hello{client_version = ClientVersion} = 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}) -> - - case dtls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb, - ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of - #alert{} = Alert -> - ssl_connection:handle_own_alert(Alert, ClientVersion, hello, State); - {Version, {Type, Session}, - ConnectionStates, Protocol0, ServerHelloExt, HashSign} -> - Protocol = case Protocol0 of - undefined -> CurrentProtocol; - _ -> Protocol0 - end, - - ssl_connection:hello(internal, {common_client_hello, Type, ServerHelloExt}, - State#state{connection_states = ConnectionStates, - negotiated_version = Version, - hashsign_algorithm = HashSign, - session = Session, - negotiated_protocol = Protocol}, ?MODULE) +hello(internal, #client_hello{cookie = <<>>, + client_version = Version} = Hello, #state{role = server, + transport_cb = Transport, + socket = Socket} = State0) -> + %% TODO: not hard code key + {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket), + Cookie = dtls_handshake:cookie(<<"secret">>, IP, Port, Hello), + VerifyRequest = dtls_handshake:hello_verify_request(Cookie, Version), + State1 = prepare_flight(State0#state{negotiated_version = Version}), + State2 = send_handshake(VerifyRequest, State1), + {Record, State} = next_record(State2), + next_event(hello, Record, State#state{tls_handshake_history = ssl_handshake:init_handshake_history()}); +hello(internal, #client_hello{cookie = Cookie} = Hello, #state{role = server, + transport_cb = Transport, + socket = Socket} = State0) -> + {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket), + %% TODO: not hard code key + case dtls_handshake:cookie(<<"secret">>, IP, Port, Hello) of + Cookie -> + handle_client_hello(Hello, State0); + _ -> + %% Handle bad cookie as new cookie request RFC 6347 4.1.2 + hello(internal, Hello#client_hello{cookie = <<>>}, State0) end; +hello(internal, #hello_verify_request{cookie = Cookie}, #state{role = client, + host = Host, port = Port, + ssl_options = SslOpts, + session = #session{own_certificate = OwnCert} + = Session0, + connection_states = ConnectionStates0, + renegotiation = {Renegotiation, _}, + session_cache = Cache, + session_cache_cb = CacheCb + } = State0) -> + State1 = prepare_flight(State0#state{tls_handshake_history = ssl_handshake:init_handshake_history()}), + Hello = dtls_handshake:client_hello(Host, Port, Cookie, ConnectionStates0, + SslOpts, + Cache, CacheCb, Renegotiation, OwnCert), + Version = Hello#client_hello.client_version, + HelloVersion = dtls_record:lowest_protocol_version(SslOpts#ssl_options.versions), + State2 = send_handshake(Hello, State1#state{negotiated_version = HelloVersion}), + State3 = State2#state{negotiated_version = Version, %% Requested version + session = + Session0#session{session_id = + Hello#client_hello.session_id}}, + {Record, State} = next_record(State3), + next_event(hello, Record, State); hello(internal, #server_hello{} = Hello, #state{connection_states = ConnectionStates0, negotiated_version = ReqVersion, @@ -273,24 +353,49 @@ hello(internal, #server_hello{} = Hello, ssl_connection:handle_session(Hello, Version, NewId, ConnectionStates, ProtoExt, Protocol, State) end; +hello(internal, {handshake, {#client_hello{cookie = <<>>} = Handshake, _}}, State) -> + %% Initial hello should not be in handshake history + {next_state, hello, State, [{next_event, internal, Handshake}]}; + +hello(internal, {handshake, {#hello_verify_request{} = Handshake, _}}, State) -> + %% hello_verify should not be in handshake history + {next_state, hello, State, [{next_event, internal, Handshake}]}; + hello(info, Event, State) -> handle_info(Event, hello, State); - hello(Type, Event, State) -> ssl_connection:hello(Type, Event, State, ?MODULE). abbreviated(info, Event, State) -> handle_info(Event, abbreviated, 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:abbreviated(Type, Event, State#state{connection_states = ConnectionStates}, ?MODULE); +abbreviated(internal = Type, #finished{} = Event, #state{connection_states = ConnectionStates} = State) -> + ssl_connection:cipher(Type, Event, prepare_flight(State#state{connection_states = ConnectionStates}), ?MODULE); abbreviated(Type, Event, State) -> ssl_connection:abbreviated(Type, Event, State, ?MODULE). certify(info, Event, State) -> handle_info(Event, certify, State); +certify(internal = Type, #server_hello_done{} = Event, State) -> + ssl_connection:certify(Type, Event, prepare_flight(State), ?MODULE); certify(Type, Event, State) -> ssl_connection:certify(Type, Event, State, ?MODULE). cipher(info, Event, State) -> handle_info(Event, cipher, State); +cipher(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:cipher(Type, Event, State#state{connection_states = ConnectionStates}, ?MODULE); +cipher(internal = Type, #finished{} = Event, #state{connection_states = ConnectionStates} = State) -> + ssl_connection:cipher(Type, Event, + prepare_flight(State#state{connection_states = ConnectionStates}), ?MODULE); cipher(Type, Event, State) -> ssl_connection:cipher(Type, Event, State, ?MODULE). @@ -310,7 +415,6 @@ connection(internal, #hello_request{}, #state{host = Host, port = Port, State1#state{session = Session0#session{session_id = Hello#client_hello.session_id}}), next_event(hello, Record, State); - connection(internal, #client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) -> %% Mitigate Computational DoS attack %% http://www.educatedguesswork.org/2011/10/ssltls_and_computational_dos.html @@ -319,14 +423,11 @@ connection(internal, #client_hello{} = Hello, #state{role = server, allow_renego %% 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}]}; - - connection(internal, #client_hello{}, #state{role = server, allow_renegotiate = false} = State0) -> Alert = ?ALERT_REC(?WARNING, ?NO_RENEGOTIATION), State1 = send_alert(Alert, State0), {Record, State} = ssl_connection:prepare_connection(State1, ?MODULE), next_event(connection, Record, State); - connection(Type, Event, State) -> ssl_connection:connection(Type, Event, State, ?MODULE). @@ -341,15 +442,25 @@ downgrade(Type, Event, State) -> %%-------------------------------------------------------------------- %% raw data from socket, unpack records -handle_info({Protocol, _, Data}, StateName, +handle_info({_,flight_retransmission_timeout}, connection, _) -> + {next_state, keep_state_and_data}; +handle_info({Ref, flight_retransmission_timeout}, StateName, + #state{flight_state = {waiting, Ref, NextTimeout}} = State0) -> + State1 = send_handshake_flight(State0#state{flight_state = {retransmit_timer, NextTimeout}}, + retransmit_epoch(StateName, State0)), + {Record, State} = next_record(State1), + next_event(StateName, Record, State); +handle_info({_, flight_retransmission_timeout}, _, _) -> + {next_state, keep_state_and_data}; +handle_info({Protocol, _, _, _, Data}, StateName, #state{data_tag = Protocol} = State0) -> - case next_tls_record(Data, State0) of + case next_dtls_record(Data, State0) of {Record, State} -> next_event(StateName, Record, State); #alert{} = Alert -> ssl_connection:handle_normal_shutdown(Alert, StateName, State0), {stop, {shutdown, own_alert}} - end; + end; handle_info({CloseTag, Socket}, StateName, #state{socket = Socket, close_tag = CloseTag, negotiated_version = Version} = State) -> @@ -380,23 +491,26 @@ handle_common_event(internal, #alert{} = Alert, StateName, ssl_connection:handle_own_alert(Alert, Version, StateName, State); %%% DTLS record protocol level handshake messages -handle_common_event(internal, #ssl_tls{type = ?HANDSHAKE} = Record, +handle_common_event(internal, #ssl_tls{type = ?HANDSHAKE, + fragment = Data}, StateName, - #state{protocol_buffers = - #protocol_buffers{dtls_packets = Packets0, - dtls_fragment_state = HsState0} = Buffers, + #state{protocol_buffers = Buffers0, negotiated_version = Version} = State0) -> try - {Packets1, HsState} = dtls_handshake:get_dtls_handshake(Record, HsState0), - State = - State0#state{protocol_buffers = - Buffers#protocol_buffers{dtls_fragment_state = HsState}}, - Events = dtls_handshake_events(Packets0 ++ Packets1), - case StateName of - connection -> - ssl_connection:hibernate_after(StateName, State, Events); - _ -> - {next_state, StateName, State, Events} + case dtls_handshake:get_dtls_handshake(Version, Data, Buffers0) of + {more_data, Buffers} -> + {Record, State} = next_record(State0#state{protocol_buffers = Buffers}), + next_event(StateName, Record, State); + {Packets, Buffers} -> + State = State0#state{protocol_buffers = Buffers}, + Events = dtls_handshake_events(Packets), + case StateName of + connection -> + ssl_connection:hibernate_after(StateName, State, Events); + _ -> + {next_state, StateName, + State#state{unprocessed_handshake_events = unprocessed_events(Events)}, Events} + end end catch throw:#alert{} = Alert -> ssl_connection:handle_own_alert(Alert, Version, StateName, State0) @@ -420,6 +534,10 @@ 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) -> + send(Transport, Socket, Data); +send(Transport, Socket, Data) -> + dtls_socket:send(Transport, Socket, Data). %%-------------------------------------------------------------------- %% Description:This function is called by a gen_fsm when it is about %% to terminate. It should be the opposite of Module:init/1 and do any @@ -442,96 +560,56 @@ format_status(Type, Data) -> %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- +handle_client_hello(#client_hello{client_version = ClientVersion} = 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} = State0) -> + + case dtls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb, + ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of + #alert{} = Alert -> + ssl_connection:handle_own_alert(Alert, ClientVersion, hello, State0); + {Version, {Type, Session}, + ConnectionStates, Protocol0, ServerHelloExt, HashSign} -> + Protocol = case Protocol0 of + undefined -> CurrentProtocol; + _ -> Protocol0 + end, -dtls_handshake_events([]) -> - throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, malformed_handshake)); -dtls_handshake_events(Packets) -> - lists:map(fun(Packet) -> - {next_event, internal, {handshake, Packet}} - end, Packets). - - -encode_handshake(Handshake, Version, ConnectionStates0, Hist0) -> - {Seq, ConnectionStates} = sequence(ConnectionStates0), - {EncHandshake, Frag} = dtls_handshake:encode_handshake(Handshake, Version, Seq), - %% DTLS does not have an equivalent version to SSLv2. So v2 hello compatibility - %% will always be false - Hist = ssl_handshake:update_handshake_history(Hist0, EncHandshake, false), - {Frag, ConnectionStates, Hist}. - -encode_change_cipher(#change_cipher_spec{}, Version, ConnectionStates) -> - dtls_record:encode_change_cipher_spec(Version, ConnectionStates). + State = prepare_flight(State0#state{connection_states = ConnectionStates, + negotiated_version = Version, + hashsign_algorithm = HashSign, + session = Session, + negotiated_protocol = Protocol}), + + ssl_connection:hello(internal, {common_client_hello, Type, ServerHelloExt}, + State, ?MODULE) + end. -encode_handshake_flight(Flight, ConnectionStates) -> - MSS = 1400, - encode_handshake_records(Flight, ConnectionStates, MSS, init_pack_records()). +encode_handshake_flight(Flight, Version, MaxFragmentSize, Epoch, ConnectionStates) -> + Fragments = lists:map(fun(Handshake) -> + dtls_handshake:fragment_handshake(Handshake, MaxFragmentSize) + end, Flight), + dtls_record:encode_handshake(Fragments, Version, Epoch, ConnectionStates). -encode_handshake_records([], CS, _MSS, Recs) -> - {finish_pack_records(Recs), CS}; +encode_change_cipher(#change_cipher_spec{}, Version, Epoch, ConnectionStates) -> + dtls_record:encode_change_cipher_spec(Version, Epoch, ConnectionStates). -encode_handshake_records([{Version, _Epoch, Frag = #change_cipher_spec{}}|Tail], ConnectionStates0, MSS, Recs0) -> - {Encoded, ConnectionStates} = - encode_change_cipher(Frag, Version, ConnectionStates0), - Recs = append_pack_records([Encoded], MSS, Recs0), - encode_handshake_records(Tail, ConnectionStates, MSS, Recs); - -encode_handshake_records([{Version, Epoch, {MsgType, MsgSeq, Bin}}|Tail], CS0, MSS, Recs0 = {Buf0, _}) -> - Space = MSS - iolist_size(Buf0), - Len = byte_size(Bin), - {Encoded, CS} = - encode_handshake_record(Version, Epoch, Space, MsgType, MsgSeq, Len, Bin, 0, MSS, [], CS0), - Recs = append_pack_records(Encoded, MSS, Recs0), - encode_handshake_records(Tail, CS, MSS, Recs). - -%% TODO: move to dtls_handshake???? -encode_handshake_record(_Version, _Epoch, _Space, _MsgType, _MsgSeq, _Len, <<>>, _Offset, _MRS, Encoded, CS) - when length(Encoded) > 0 -> - %% make sure we encode at least one segment (for empty messages like Server Hello Done - {lists:reverse(Encoded), CS}; - -encode_handshake_record(Version, Epoch, Space, MsgType, MsgSeq, Len, Bin, - Offset, MRS, Encoded0, CS0) -> - MaxFragmentLen = Space - 25, - {BinFragment, Rest} = - case Bin of - <<BinFragment0:MaxFragmentLen/bytes, Rest0/binary>> -> - {BinFragment0, Rest0}; - _ -> - {Bin, <<>>} - end, - FragLength = byte_size(BinFragment), - Frag = [MsgType, ?uint24(Len), ?uint16(MsgSeq), ?uint24(Offset), ?uint24(FragLength), BinFragment], - %% TODO Real solution, now avoid dialyzer error {Encoded, CS} = ssl_record:encode_handshake({Epoch, Frag}, Version, CS0), - {Encoded, CS} = ssl_record:encode_handshake(Frag, Version, CS0), - encode_handshake_record(Version, Epoch, MRS, MsgType, MsgSeq, Len, Rest, Offset + FragLength, MRS, [Encoded|Encoded0], CS). - -init_pack_records() -> - {[], []}. - -append_pack_records([], MSS, Recs = {Buf0, Acc0}) -> - Remaining = MSS - iolist_size(Buf0), - if Remaining < 12 -> - {[], [lists:reverse(Buf0)|Acc0]}; - true -> - Recs - end; -append_pack_records([Head|Tail], MSS, {Buf0, Acc0}) -> - TotLen = iolist_size(Buf0) + iolist_size(Head), - if TotLen > MSS -> - append_pack_records(Tail, MSS, {[Head], [lists:reverse(Buf0)|Acc0]}); - true -> - append_pack_records(Tail, MSS, {[Head|Buf0], Acc0}) - end. +encode_data(Data, Version, ConnectionStates0)-> + dtls_record:encode_data(Data, Version, ConnectionStates0). -finish_pack_records({[], Acc}) -> - lists:reverse(Acc); -finish_pack_records({Buf, Acc}) -> - lists:reverse([lists:reverse(Buf)|Acc]). +encode_alert(#alert{} = Alert, Version, ConnectionStates) -> + dtls_record:encode_alert_record(Alert, Version, ConnectionStates). decode_alerts(Bin) -> ssl_alert:decode(Bin). -initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions}, User, +initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions, _}, User, {CbModule, DataTag, CloseTag, ErrorTag}) -> #ssl_options{beast_mitigation = BeastMitigation} = SSLOptions, ConnectionStates = dtls_record:init_connection_states(Role, BeastMitigation), @@ -566,10 +644,11 @@ initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions}, User, renegotiation = {false, first}, allow_renegotiate = SSLOptions#ssl_options.client_renegotiation, start_or_recv_from = undefined, - protocol_cb = ?MODULE + protocol_cb = ?MODULE, + flight_buffer = new_flight() }. -next_tls_record(Data, #state{protocol_buffers = #protocol_buffers{ +next_dtls_record(Data, #state{protocol_buffers = #protocol_buffers{ dtls_record_buffer = Buf0, dtls_cipher_texts = CT0} = Buffers} = State0) -> case dtls_record:get_dtls_records(Data, Buf0) of @@ -578,14 +657,15 @@ next_tls_record(Data, #state{protocol_buffers = #protocol_buffers{ next_record(State0#state{protocol_buffers = Buffers#protocol_buffers{dtls_record_buffer = Buf1, dtls_cipher_texts = CT1}}); - #alert{} = Alert -> Alert - end. + end. -next_record(#state{%%flight = #flight{state = finished}, - protocol_buffers = - #protocol_buffers{dtls_packets = [], dtls_cipher_texts = [CT | Rest]} +next_record(#state{unprocessed_handshake_events = N} = State) when N > 0 -> + {no_record, State#state{unprocessed_handshake_events = N-1}}; + +next_record(#state{protocol_buffers = + #protocol_buffers{dtls_cipher_texts = [CT | Rest]} = Buffers, connection_states = ConnStates0} = State) -> case dtls_record:decode_cipher_text(CT, ConnStates0) of @@ -596,9 +676,15 @@ next_record(#state{%%flight = #flight{state = finished}, #alert{} = Alert -> {Alert, State} end; -next_record(#state{socket = Socket, - transport_cb = Transport} = State) -> %% when FlightState =/= finished - ssl_socket:setopts(Transport, Socket, [{active,once}]), +next_record(#state{role = server, + socket = {Listener, {Client, _}}, + transport_cb = gen_udp} = State) -> + dtls_udp_listener:active_once(Listener, Client, self()), + {no_record, State}; +next_record(#state{role = client, + socket = {_Server, Socket}, + transport_cb = Transport} = State) -> + dtls_socket:setopts(Transport, Socket, [{active,once}]), {no_record, State}; next_record(State) -> {no_record, State}. @@ -624,75 +710,89 @@ passive_receive(State0 = #state{user_data_buffer = Buffer}, StateName) -> next_event(StateName, Record, State) -> next_event(StateName, Record, State, []). -next_event(connection = StateName, no_record, State0, Actions) -> +next_event(connection = StateName, no_record, + #state{connection_states = #{current_read := #{epoch := CurrentEpoch}}} = State0, Actions) -> case next_record_if_active(State0) of {no_record, State} -> ssl_connection:hibernate_after(StateName, State, Actions); - {#ssl_tls{} = Record, State} -> + {#ssl_tls{epoch = CurrentEpoch} = Record, State} -> {next_state, StateName, State, [{next_event, internal, {protocol_record, Record}} | Actions]}; + {#ssl_tls{epoch = Epoch, + type = ?HANDSHAKE, + version = _Version}, State1} = _Record when Epoch == CurrentEpoch-1 -> + State = send_handshake_flight(State1, Epoch), + {next_state, StateName, State, Actions}; + {#ssl_tls{epoch = _Epoch, + version = _Version}, State} -> + %% TODO maybe buffer later epoch + {next_state, StateName, State, Actions}; {#alert{} = Alert, State} -> {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} end; -next_event(StateName, Record, State, Actions) -> +next_event(StateName, Record, + #state{connection_states = #{current_read := #{epoch := CurrentEpoch}}} = State, Actions) -> case Record of no_record -> {next_state, StateName, State, Actions}; - #ssl_tls{} = Record -> - {next_state, StateName, State, [{next_event, internal, {protocol_record, Record}} | Actions]}; + #ssl_tls{epoch = CurrentEpoch, + version = Version} = Record -> + {next_state, StateName, + dtls_version(StateName, Version, State), + [{next_event, internal, {protocol_record, Record}} | Actions]}; + #ssl_tls{epoch = _Epoch, + version = _Version} = _Record -> + %% TODO maybe buffer later epoch + {next_state, StateName, State, Actions}; #alert{} = Alert -> {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} end. -%% TODO This generates dialyzer warnings, has to be handled differently. -%% handle_packet(Address, Port, Packet) -> -%% try dtls_record:get_dtls_records(Packet, <<>>) of -%% %% expect client hello -%% {[#ssl_tls{type = ?HANDSHAKE, version = {254, _}} = Record], <<>>} -> -%% handle_dtls_client_hello(Address, Port, Record); -%% _Other -> -%% {error, not_dtls} -%% catch -%% _Class:_Error -> -%% {error, not_dtls} -%% end. - -%% handle_dtls_client_hello(Address, Port, -%% #ssl_tls{epoch = Epoch, sequence_number = Seq, -%% version = Version} = Record) -> -%% {[{Hello, _}], _} = -%% dtls_handshake:get_dtls_handshake(Record, -%% dtls_handshake:dtls_handshake_new_flight(undefined)), -%% #client_hello{client_version = {Major, Minor}, -%% random = Random, -%% session_id = SessionId, -%% cipher_suites = CipherSuites, -%% compression_methods = CompressionMethods} = Hello, -%% CookieData = [address_to_bin(Address, Port), -%% <<?BYTE(Major), ?BYTE(Minor)>>, -%% Random, SessionId, CipherSuites, CompressionMethods], -%% Cookie = crypto:hmac(sha, <<"secret">>, CookieData), - -%% case Hello of -%% #client_hello{cookie = Cookie} -> -%% accept; - -%% _ -> -%% %% generate HelloVerifyRequest -%% {RequestFragment, _} = dtls_handshake:encode_handshake( -%% dtls_handshake:hello_verify_request(Cookie), -%% Version, 0), -%% HelloVerifyRequest = -%% dtls_record:encode_tls_cipher_text(?HANDSHAKE, Version, Epoch, Seq, RequestFragment), -%% {reply, HelloVerifyRequest} -%% end. - -%% address_to_bin({A,B,C,D}, Port) -> -%% <<0:80,16#ffff:16,A,B,C,D,Port:16>>; -%% address_to_bin({A,B,C,D,E,F,G,H}, Port) -> -%% <<A:16,B:16,C:16,D:16,E:16,F:16,G:16,H:16,Port:16>>. - -sequence(#{write_msg_seq := Seq} = ConnectionState) -> - {Seq, ConnectionState#{write_msg_seq => Seq + 1}}. +dtls_version(hello, Version, #state{role = server} = State) -> + State#state{negotiated_version = Version}; %%Inital version +dtls_version(_,_, State) -> + State. + +prepare_flight(#state{flight_buffer = Flight, + connection_states = ConnectionStates0, + protocol_buffers = + #protocol_buffers{} = Buffers} = State) -> + ConnectionStates = dtls_record:save_current_connection_state(ConnectionStates0, write), + State#state{flight_buffer = next_flight(Flight), + connection_states = ConnectionStates, + protocol_buffers = Buffers#protocol_buffers{ + dtls_handshake_next_fragments = [], + dtls_handshake_later_fragments = []}}. +new_flight() -> + #{next_sequence => 0, + handshakes => [], + change_cipher_spec => undefined, + handshakes_after_change_cipher_spec => []}. + +next_flight(Flight) -> + Flight#{handshakes => [], + change_cipher_spec => undefined, + handshakes_after_change_cipher_spec => []}. + + +start_flight(#state{transport_cb = gen_udp, + flight_state = {retransmit_timer, Timeout}} = State) -> + Ref = erlang:make_ref(), + _ = erlang:send_after(Timeout, self(), {Ref, flight_retransmission_timeout}), + State#state{flight_state = {waiting, Ref, new_timeout(Timeout)}}; + +start_flight(State) -> + %% No retransmision needed i.e DTLS over SCTP + State#state{flight_state = reliable}. + +new_timeout(N) when N =< 30 -> + N * 2; +new_timeout(_) -> + 60. + +dtls_handshake_events(Packets) -> + lists:map(fun(Packet) -> + {next_event, internal, {handshake, Packet}} + end, Packets). renegotiate(#state{role = client} = State, Actions) -> %% Handle same way as if server requested @@ -722,3 +822,27 @@ handle_alerts([Alert | Alerts], {next_state, StateName, State}) -> handle_alerts(Alerts, ssl_connection:handle_alert(Alert, StateName, State)); handle_alerts([Alert | Alerts], {next_state, StateName, State, _Actions}) -> handle_alerts(Alerts, ssl_connection:handle_alert(Alert, StateName, State)). + +retransmit_epoch(StateName, #state{connection_states = ConnectionStates}) -> + #{epoch := Epoch} = + ssl_record:current_connection_state(ConnectionStates, write), + case StateName of + connection -> + Epoch-1; + _ -> + Epoch + end. + +update_handshake_history(#hello_verify_request{}, _, Hist) -> + Hist; +update_handshake_history(_, Handshake, Hist) -> + %% DTLS never needs option "v2_hello_compatible" to be true + ssl_handshake:update_handshake_history(Hist, iolist_to_binary(Handshake), false). + +unprocessed_events(Events) -> + %% The first handshake event will be processed immediately + %% as it is entered first in the event queue and + %% when it is processed there will be length(Events)-1 + %% handshake events left to process before we should + %% process more TLS-records received on the socket. + erlang:length(Events)-1. |