diff options
Diffstat (limited to 'lib/ssl/src/dtls_connection.erl')
| -rw-r--r-- | lib/ssl/src/dtls_connection.erl | 1164 |
1 files changed, 717 insertions, 447 deletions
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl index 745db788e7..03725089dd 100644 --- a/lib/ssl/src/dtls_connection.erl +++ b/lib/ssl/src/dtls_connection.erl @@ -39,21 +39,19 @@ -export([start_fsm/8, start_link/7, init/1]). %% State transition handling --export([next_record/1, next_event/3, next_event/4]). +-export([next_record/1, next_event/3, next_event/4, handle_common_event/4]). %% Handshake handling --export([renegotiate/2, - reinit_handshake_data/1, - send_handshake/2, queue_handshake/2, queue_change_cipher/2, - select_sni_extension/1]). +-export([renegotiate/2, send_handshake/2, + queue_handshake/2, queue_change_cipher/2, + reinit_handshake_data/1, select_sni_extension/1, empty_connection_state/2]). %% Alert and close handling --export([encode_alert/3,send_alert/2, close/5]). +-export([encode_alert/3,send_alert/2, close/5, protocol_name/0]). %% Data handling - --export([encode_data/3, passive_receive/2, next_record_if_active/1, handle_common_event/4, - send/3, socket/5]). +-export([encode_data/3, passive_receive/2, next_record_if_active/1, + send/3, socket/5, setopts/3, getopts/3]). %% gen_statem state functions -export([init/3, error/3, downgrade/3, %% Initiation and take down states @@ -64,6 +62,9 @@ %%==================================================================== %% Internal application API +%%==================================================================== +%%==================================================================== +%% Setup %%==================================================================== start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = false},_, Tracker} = Opts, User, {CbModule, _,_, _} = CbInfo, @@ -79,9 +80,227 @@ start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = false},_, Tracker} Error end. -send_handshake(Handshake, #state{connection_states = ConnectionStates} = States) -> +%%-------------------------------------------------------------------- +-spec start_link(atom(), host(), inet:port_number(), port(), list(), pid(), tuple()) -> + {ok, pid()} | ignore | {error, reason()}. +%% +%% Description: Creates a gen_statem process which calls Module:init/1 to +%% initialize. +%%-------------------------------------------------------------------- +start_link(Role, Host, Port, Socket, Options, User, CbInfo) -> + {ok, proc_lib:spawn_link(?MODULE, init, [[Role, Host, Port, Socket, Options, User, CbInfo]])}. + +init([Role, Host, Port, Socket, Options, User, CbInfo]) -> + process_flag(trap_exit, true), + State0 = initial_state(Role, Host, Port, Socket, Options, User, CbInfo), + try + State = ssl_connection:ssl_config(State0#state.ssl_options, Role, State0), + gen_statem:enter_loop(?MODULE, [], init, State) + catch + throw:Error -> + gen_statem:enter_loop(?MODULE, [], error, {Error,State0}) + end. +%%==================================================================== +%% State transition handling +%%==================================================================== +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 = [#ssl_tls{epoch = Epoch} = CT | Rest]} + = Buffers, + connection_states = #{current_read := #{epoch := Epoch}} = ConnectionStates} = State) -> + CurrentRead = dtls_record:get_connection_state_by_epoch(Epoch, ConnectionStates, read), + case dtls_record:replay_detect(CT, CurrentRead) of + false -> + decode_cipher_text(State#state{connection_states = ConnectionStates}) ; + true -> + %% Ignore replayed record + next_record(State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + connection_states = ConnectionStates}) + end; +next_record(#state{protocol_buffers = + #protocol_buffers{dtls_cipher_texts = [#ssl_tls{epoch = Epoch} | Rest]} + = Buffers, + connection_states = #{current_read := #{epoch := CurrentEpoch}} = ConnectionStates} = State) + when Epoch > CurrentEpoch -> + %% TODO Buffer later Epoch message, drop it for now + next_record(State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + connection_states = ConnectionStates}); +next_record(#state{protocol_buffers = + #protocol_buffers{dtls_cipher_texts = [ _ | Rest]} + = Buffers, + connection_states = ConnectionStates} = State) -> + %% Drop old epoch message + next_record(State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + connection_states = ConnectionStates}); +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} = DTLSSocket, + close_tag = CloseTag, + transport_cb = Transport} = State) -> + case dtls_socket:setopts(Transport, Socket, [{active,once}]) of + ok -> + {no_record, State}; + _ -> + self() ! {CloseTag, DTLSSocket}, + {no_record, State} + end; +next_record(State) -> + {no_record, State}. + +next_event(StateName, Record, State) -> + next_event(StateName, Record, State, []). + +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{epoch = CurrentEpoch, + type = ?HANDSHAKE, + version = Version} = Record, State1} -> + State = dtls_version(StateName, Version, State1), + {next_state, StateName, State, + [{next_event, internal, {protocol_record, Record}} | Actions]}; + {#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 -> + {State2, MoreActions} = send_handshake_flight(State1, CurrentEpoch), + {NextRecord, State} = next_record(State2), + next_event(StateName, NextRecord, State, Actions ++ MoreActions); + %% From FLIGHT perspective CHANGE_CIPHER_SPEC is treated as a handshake + {#ssl_tls{epoch = Epoch, + type = ?CHANGE_CIPHER_SPEC, + version = _Version}, State1} = _Record when Epoch == CurrentEpoch-1 -> + {State2, MoreActions} = send_handshake_flight(State1, CurrentEpoch), + {NextRecord, State} = next_record(State2), + next_event(StateName, NextRecord, State, Actions ++ MoreActions); + {#ssl_tls{epoch = _Epoch, + version = _Version}, State1} -> + %% TODO maybe buffer later epoch + {Record, State} = next_record(State1), + next_event(StateName, Record, State, Actions); + {#alert{} = Alert, State} -> + {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} + end; +next_event(connection = StateName, Record, + #state{connection_states = #{current_read := #{epoch := CurrentEpoch}}} = State0, Actions) -> + case Record of + #ssl_tls{epoch = CurrentEpoch, + type = ?HANDSHAKE, + version = Version} = Record -> + State = dtls_version(StateName, Version, State0), + {next_state, StateName, State, + [{next_event, internal, {protocol_record, Record}} | Actions]}; + #ssl_tls{epoch = CurrentEpoch} -> + {next_state, StateName, State0, [{next_event, internal, {protocol_record, Record}} | Actions]}; + #ssl_tls{epoch = Epoch, + type = ?HANDSHAKE, + version = _Version} when Epoch == CurrentEpoch-1 -> + {State1, MoreActions} = send_handshake_flight(State0, CurrentEpoch), + {NextRecord, State} = next_record(State1), + next_event(StateName, NextRecord, State, Actions ++ MoreActions); + %% From FLIGHT perspective CHANGE_CIPHER_SPEC is treated as a handshake + #ssl_tls{epoch = Epoch, + type = ?CHANGE_CIPHER_SPEC, + version = _Version} when Epoch == CurrentEpoch-1 -> + {State1, MoreActions} = send_handshake_flight(State0, CurrentEpoch), + {NextRecord, State} = next_record(State1), + next_event(StateName, NextRecord, State, Actions ++ MoreActions); + _ -> + next_event(StateName, no_record, State0, Actions) + end; +next_event(StateName, Record, + #state{connection_states = #{current_read := #{epoch := CurrentEpoch}}} = State0, Actions) -> + case Record of + no_record -> + {next_state, StateName, State0, Actions}; + #ssl_tls{epoch = CurrentEpoch, + version = Version} = Record -> + State = dtls_version(StateName, Version, State0), + {next_state, StateName, State, + [{next_event, internal, {protocol_record, Record}} | Actions]}; + #ssl_tls{epoch = _Epoch, + version = _Version} = _Record -> + %% TODO maybe buffer later epoch + {Record, State} = next_record(State0), + next_event(StateName, Record, State, Actions); + #alert{} = Alert -> + {next_state, StateName, State0, [{next_event, internal, Alert} | Actions]} + end. + +handle_common_event(internal, #alert{} = Alert, StateName, + #state{negotiated_version = Version} = State) -> + handle_own_alert(Alert, Version, StateName, State); +%%% DTLS record protocol level handshake messages +handle_common_event(internal, #ssl_tls{type = ?HANDSHAKE, + fragment = Data}, + StateName, + #state{protocol_buffers = Buffers0, + negotiated_version = Version} = State0) -> + try + case dtls_handshake:get_dtls_handshake(Version, Data, Buffers0) of + {[], 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), + {next_state, StateName, + State#state{unprocessed_handshake_events = unprocessed_events(Events)}, Events} + end + catch throw:#alert{} = Alert -> + handle_own_alert(Alert, Version, StateName, State0) + end; +%%% DTLS record protocol level application data messages +handle_common_event(internal, #ssl_tls{type = ?APPLICATION_DATA, fragment = Data}, StateName, State) -> + {next_state, StateName, State, [{next_event, internal, {application_data, Data}}]}; +%%% DTLS record protocol level change cipher messages +handle_common_event(internal, #ssl_tls{type = ?CHANGE_CIPHER_SPEC, fragment = Data}, StateName, State) -> + {next_state, StateName, State, [{next_event, internal, #change_cipher_spec{type = Data}}]}; +%%% DTLS record protocol level Alert messages +handle_common_event(internal, #ssl_tls{type = ?ALERT, fragment = EncAlerts}, StateName, + #state{negotiated_version = Version} = State) -> + case decode_alerts(EncAlerts) of + Alerts = [_|_] -> + handle_alerts(Alerts, {next_state, StateName, State}); + #alert{} = Alert -> + handle_own_alert(Alert, Version, StateName, State) + end; +%% Ignore unknown TLS record level protocol messages +handle_common_event(internal, #ssl_tls{type = _Unknown}, StateName, State) -> + {next_state, StateName, State}. + +%%==================================================================== +%% Handshake handling +%%==================================================================== + +renegotiate(#state{role = client} = State, Actions) -> + %% Handle same way as if server requested + %% the renegotiation + {next_state, connection, State, + [{next_event, internal, #hello_request{}} | Actions]}; + +renegotiate(#state{role = server} = State0, Actions) -> + HelloRequest = ssl_handshake:hello_request(), + State1 = prepare_flight(State0), + {State2, MoreActions} = send_handshake(HelloRequest, State1), + {Record, State} = next_record(State2), + next_event(hello, Record, State, Actions ++ MoreActions). + +send_handshake(Handshake, #state{connection_states = ConnectionStates} = State) -> #{epoch := Epoch} = ssl_record:current_connection_state(ConnectionStates, write), - send_handshake_flight(queue_handshake(Handshake, States), Epoch). + send_handshake_flight(queue_handshake(Handshake, State), Epoch). queue_handshake(Handshake0, #state{tls_handshake_history = Hist0, negotiated_version = Version, @@ -104,93 +323,21 @@ queue_handshake(Handshake0, #state{tls_handshake_history = Hist0, next_sequence => Seq +1}, tls_handshake_history = Hist}. - -send_handshake_flight(#state{socket = Socket, - transport_cb = Transport, - 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(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}); - -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}); - -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} = - encode_alert(Alert, Version, ConnectionStates0), - send(Transport, Socket, BinMsg), - State0#state{connection_states = ConnectionStates}. - -close(downgrade, _,_,_,_) -> - ok; -%% Other -close(_, Socket, Transport, _,_) -> - 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(), flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT}, - protocol_buffers = + flight_buffer = new_flight(), + protocol_buffers = Buffers#protocol_buffers{ - dtls_handshake_next_seq = 0, + dtls_handshake_next_seq = 0, dtls_handshake_next_fragments = [], dtls_handshake_later_fragments = [] }}. @@ -200,42 +347,82 @@ select_sni_extension(#client_hello{extensions = HelloExtensions}) -> select_sni_extension(_) -> undefined. -socket(Pid, Transport, Socket, Connection, _) -> - dtls_socket:socket(Pid, Transport, Socket, Connection). +empty_connection_state(ConnectionEnd, BeastMitigation) -> + Empty = ssl_record:empty_connection_state(ConnectionEnd, BeastMitigation), + dtls_record:empty_connection_state(Empty). %%==================================================================== -%% tls_connection_sup API +%% Alert and close handling +%%==================================================================== +encode_alert(#alert{} = Alert, Version, ConnectionStates) -> + dtls_record:encode_alert_record(Alert, Version, ConnectionStates). + +send_alert(Alert, #state{negotiated_version = Version, + socket = Socket, + transport_cb = Transport, + connection_states = ConnectionStates0} = State0) -> + {BinMsg, ConnectionStates} = + encode_alert(Alert, Version, ConnectionStates0), + send(Transport, Socket, BinMsg), + State0#state{connection_states = ConnectionStates}. + +close(downgrade, _,_,_,_) -> + ok; +%% Other +close(_, Socket, Transport, _,_) -> + dtls_socket:close(Transport,Socket). + +protocol_name() -> + "DTLS". + %%==================================================================== +%% Data handling +%%==================================================================== -%%-------------------------------------------------------------------- --spec start_link(atom(), host(), inet:port_number(), port(), list(), pid(), tuple()) -> - {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 -%% does not return until Module:init/1 has returned. -%%-------------------------------------------------------------------- -start_link(Role, Host, Port, Socket, Options, User, CbInfo) -> - {ok, proc_lib:spawn_link(?MODULE, init, [[Role, Host, Port, Socket, Options, User, CbInfo]])}. +encode_data(Data, Version, ConnectionStates0)-> + dtls_record:encode_data(Data, Version, ConnectionStates0). -init([Role, Host, Port, Socket, Options, User, CbInfo]) -> - process_flag(trap_exit, true), - State0 = initial_state(Role, Host, Port, Socket, Options, User, CbInfo), - try - State = ssl_connection:ssl_config(State0#state.ssl_options, Role, State0), - gen_statem:enter_loop(?MODULE, [], init, State) - catch - throw:Error -> - gen_statem:enter_loop(?MODULE, [], error, {Error,State0}) +passive_receive(State0 = #state{user_data_buffer = Buffer}, StateName) -> + case Buffer of + <<>> -> + {Record, State} = next_record(State0), + next_event(StateName, Record, State); + _ -> + {Record, State} = ssl_connection:read_application_data(<<>>, State0), + next_event(StateName, Record, State) end. +next_record_if_active(State = + #state{socket_options = + #socket_options{active = false}}) -> + {no_record ,State}; -callback_mode() -> - state_functions. +next_record_if_active(State) -> + next_record(State). + +send(Transport, {_, {{_,_}, _} = Socket}, Data) -> + send(Transport, Socket, Data); +send(Transport, Socket, Data) -> + dtls_socket:send(Transport, Socket, Data). + +socket(Pid, Transport, Socket, Connection, _) -> + dtls_socket:socket(Pid, Transport, Socket, Connection). + +setopts(Transport, Socket, Other) -> + dtls_socket:setopts(Transport, Socket, Other). + +getopts(Transport, Socket, Tag) -> + dtls_socket:getopts(Transport, Socket, Tag). %%-------------------------------------------------------------------- %% State functions %%-------------------------------------------------------------------- - +%%-------------------------------------------------------------------- +-spec init(gen_statem:event_type(), + {start, timeout()} | term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +init(enter, _, State) -> + {keep_state, State}; init({call, From}, {start, Timeout}, #state{host = Host, port = Port, role = client, ssl_options = SslOpts, @@ -250,7 +437,7 @@ init({call, From}, {start, Timeout}, Cache, CacheCb, Renegotiation, Cert), Version = Hello#client_hello.client_version, - HelloVersion = dtls_record:lowest_protocol_version(SslOpts#ssl_options.versions), + HelloVersion = dtls_record:hello_version(Version, SslOpts#ssl_options.versions), State1 = prepare_flight(State0#state{negotiated_version = Version}), {State2, Actions} = send_handshake(Hello, State1#state{negotiated_version = HelloVersion}), State3 = State2#state{negotiated_version = Version, %% Requested version @@ -263,19 +450,32 @@ 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) -> - ssl_connection:init(Type, Event, - State#state{flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT}}, - ?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:init(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:init(Type, Event, State, ?MODULE). - + gen_handshake(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec error(gen_statem:event_type(), + {start, timeout()} | term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +error(enter, _, State) -> + {keep_state, State}; error({call, From}, {start, _Timeout}, {Error, State}) -> {stop_and_reply, normal, {reply, From, {error, Error}}, State}; -error({call, From}, Msg, State) -> - handle_call(Msg, From, error, State); +error({call, _} = Call, Msg, State) -> + gen_handshake(?FUNCTION_NAME, Call, Msg, State); error(_, _, _) -> {keep_state_and_data, [postpone]}. @@ -285,29 +485,46 @@ error(_, _, _) -> #state{}) -> gen_statem:state_function_result(). %%-------------------------------------------------------------------- +hello(enter, _, #state{role = server} = State) -> + {keep_state, State}; +hello(enter, _, #state{role = client} = State0) -> + {State, Actions} = handle_flight_timer(State0), + {keep_state, State, Actions}; hello(internal, #client_hello{cookie = <<>>, client_version = Version} = Hello, #state{role = server, transport_cb = Transport, - socket = Socket} = State0) -> - %% TODO: not hard code key + socket = Socket, + protocol_specific = #{current_cookie_secret := Secret}} = State0) -> {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket), - Cookie = dtls_handshake:cookie(<<"secret">>, IP, Port, Hello), - VerifyRequest = dtls_handshake:hello_verify_request(Cookie, Version), + Cookie = dtls_handshake:cookie(Secret, IP, Port, Hello), + %% FROM RFC 6347 regarding HelloVerifyRequest message: + %% The server_version field has the same syntax as in TLS. However, in + %% order to avoid the requirement to do version negotiation in the + %% initial handshake, DTLS 1.2 server implementations SHOULD use DTLS + %% version 1.0 regardless of the version of TLS that is expected to be + %% negotiated. + VerifyRequest = dtls_handshake:hello_verify_request(Cookie, ?HELLO_VERIFY_REQUEST_VERSION), State1 = prepare_flight(State0#state{negotiated_version = Version}), {State2, Actions} = send_handshake(VerifyRequest, State1), {Record, State} = next_record(State2), - next_event(hello, Record, State#state{tls_handshake_history = ssl_handshake:init_handshake_history()}, Actions); + next_event(?FUNCTION_NAME, Record, State#state{tls_handshake_history = ssl_handshake:init_handshake_history()}, Actions); hello(internal, #client_hello{cookie = Cookie} = Hello, #state{role = server, transport_cb = Transport, - socket = Socket} = State0) -> + socket = Socket, + protocol_specific = #{current_cookie_secret := Secret, + previous_cookie_secret := PSecret}} = State0) -> {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket), - %% TODO: not hard code key - case dtls_handshake:cookie(<<"secret">>, IP, Port, Hello) of + 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) + case dtls_handshake:cookie(PSecret, 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 end; hello(internal, #hello_verify_request{cookie = Cookie}, #state{role = client, host = Host, port = Port, @@ -319,19 +536,20 @@ hello(internal, #hello_verify_request{cookie = Cookie}, #state{role = client, 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, Actions} = send_handshake(Hello, State1#state{negotiated_version = HelloVersion}), + State1 = prepare_flight(State0#state{tls_handshake_history = ssl_handshake:init_handshake_history()}), + + {State2, Actions} = send_handshake(Hello, State1), 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, Actions); + next_event(?FUNCTION_NAME, Record, State, Actions); hello(internal, #server_hello{} = Hello, #state{connection_states = ConnectionStates0, negotiated_version = ReqVersion, @@ -340,81 +558,119 @@ hello(internal, #server_hello{} = Hello, ssl_options = SslOptions} = State) -> case dtls_handshake:hello(Hello, SslOptions, ConnectionStates0, Renegotiation) of #alert{} = Alert -> - ssl_connection:handle_own_alert(Alert, ReqVersion, hello, State); + handle_own_alert(Alert, ReqVersion, ?FUNCTION_NAME, State); {Version, NewId, ConnectionStates, ProtoExt, Protocol} -> 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}]}; + {next_state, ?FUNCTION_NAME, 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}]}; + {next_state, ?FUNCTION_NAME, State, [{next_event, internal, Handshake}]}; hello(info, Event, State) -> - handle_info(Event, hello, State); + gen_info(Event, ?FUNCTION_NAME, State); hello(state_timeout, Event, State) -> - handle_state_timeout(Event, hello, State); + handle_state_timeout(Event, ?FUNCTION_NAME, State); hello(Type, Event, State) -> - ssl_connection:hello(Type, Event, State, ?MODULE). + gen_handshake(?FUNCTION_NAME, Type, Event, State). +%%-------------------------------------------------------------------- +-spec abbreviated(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +abbreviated(enter, _, State0) -> + {State, Actions} = handle_flight_timer(State0), + {keep_state, State, Actions}; abbreviated(info, Event, State) -> - handle_info(Event, abbreviated, 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:abbreviated(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:abbreviated(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, abbreviated, State); + handle_state_timeout(Event, ?FUNCTION_NAME, State); abbreviated(Type, Event, State) -> - ssl_connection:abbreviated(Type, Event, State, ?MODULE). - + gen_handshake(?FUNCTION_NAME, Type, Event, State). +%%-------------------------------------------------------------------- +-spec certify(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +certify(enter, _, State0) -> + {State, Actions} = handle_flight_timer(State0), + {keep_state, State, Actions}; certify(info, Event, State) -> - handle_info(Event, certify, 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(internal, #change_cipher_spec{type = <<1>>}, State0) -> + {State1, Actions0} = send_handshake_flight(State0, retransmit_epoch(?FUNCTION_NAME, State0)), + {Record, State2} = next_record(State1), + {next_state, ?FUNCTION_NAME, State, Actions} = next_event(?FUNCTION_NAME, Record, State2, Actions0), + %% This will reset the retransmission timer by repeating the enter state event + {repeat_state, State, Actions}; certify(state_timeout, Event, State) -> - handle_state_timeout(Event, certify, State); + handle_state_timeout(Event, ?FUNCTION_NAME, State); certify(Type, Event, State) -> - ssl_connection:certify(Type, Event, State, ?MODULE). + gen_handshake(?FUNCTION_NAME, Type, Event, State). +%%-------------------------------------------------------------------- +-spec cipher(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +cipher(enter, _, State0) -> + {State, Actions} = handle_flight_timer(State0), + {keep_state, State, Actions}; cipher(info, Event, State) -> - handle_info(Event, cipher, 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), ConnectionStates = dtls_record:next_epoch(ConnectionStates1, read), - ssl_connection:cipher(Type, Event, State#state{connection_states = ConnectionStates}, ?MODULE); + ssl_connection:?FUNCTION_NAME(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, - flight_state = connection}), - ?MODULE); + ssl_connection:?FUNCTION_NAME(Type, Event, + prepare_flight(State#state{connection_states = ConnectionStates, + flight_state = connection}), + ?MODULE); cipher(state_timeout, Event, State) -> - handle_state_timeout(Event, cipher, State); + handle_state_timeout(Event, ?FUNCTION_NAME, State); cipher(Type, Event, State) -> - ssl_connection:cipher(Type, Event, State, ?MODULE). + ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). +%%-------------------------------------------------------------------- +-spec connection(gen_statem:event_type(), + #hello_request{} | #client_hello{}| term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +connection(enter, _, State) -> + {keep_state, State}; connection(info, Event, State) -> - handle_info(Event, connection, 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, - ssl_options = SslOpts, - connection_states = ConnectionStates0, - renegotiation = {Renegotiation, _}} = State0) -> + session = #session{own_certificate = Cert} = Session0, + session_cache = Cache, session_cache_cb = CacheCb, + ssl_options = SslOpts, + connection_states = ConnectionStates0, + renegotiation = {Renegotiation, _}} = State0) -> + Hello = dtls_handshake:client_hello(Host, Port, ConnectionStates0, SslOpts, Cache, CacheCb, Renegotiation, Cert), - {State1, Actions} = send_handshake(Hello, State0), + Version = Hello#client_hello.client_version, + HelloVersion = dtls_record:hello_version(Version, SslOpts#ssl_options.versions), + State1 = prepare_flight(State0), + {State2, Actions} = send_handshake(Hello, State1#state{negotiated_version = HelloVersion}), {Record, State} = next_record( - State1#state{session = Session0#session{session_id + State2#state{flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT}, + session = Session0#session{session_id = Hello#client_hello.session_id}}), next_event(hello, Record, State, Actions); connection(internal, #client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) -> @@ -424,125 +680,35 @@ connection(internal, #client_hello{} = Hello, #state{role = server, allow_renego %% 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}]}; + {next_state, hello, State#state{allow_renegotiate = false, renegotiation = {true, peer}}, + [{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); + next_event(?FUNCTION_NAME, Record, State); connection(Type, Event, State) -> - ssl_connection:connection(Type, Event, State, ?MODULE). - -downgrade(Type, Event, State) -> - ssl_connection:downgrade(Type, Event, State, ?MODULE). + ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). +%%TODO does this make sense for DTLS ? %%-------------------------------------------------------------------- -%% Description: This function is called by a gen_fsm when it receives any -%% other message than a synchronous or asynchronous event -%% (or a system message). +-spec downgrade(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). %%-------------------------------------------------------------------- +downgrade(enter, _, State) -> + {keep_state, State}; +downgrade(Type, Event, State) -> + ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). -%% raw data from socket, unpack records -handle_info({Protocol, _, _, _, Data}, StateName, - #state{data_tag = Protocol} = State0) -> - 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; -handle_info({CloseTag, Socket}, StateName, - #state{socket = Socket, close_tag = CloseTag, - negotiated_version = Version} = State) -> - %% Note that as of DTLS 1.2 (TLS 1.1), - %% failure to properly close a connection no longer requires that a - %% session not be resumed. This is a change from DTLS 1.0 to conform - %% with widespread implementation practice. - case Version of - {254, N} when N =< 253 -> - ok; - _ -> - %% As invalidate_sessions here causes performance issues, - %% we will conform to the widespread implementation - %% practice and go aginst the spec - %%invalidate_session(Role, Host, Port, Session) - ok - end, - ssl_connection:handle_normal_shutdown(?ALERT_REC(?FATAL, ?CLOSE_NOTIFY), StateName, State), - {stop, {shutdown, transport_closed}}; -handle_info(Msg, StateName, State) -> - ssl_connection:handle_info(Msg, StateName, State). - -handle_call(Event, From, StateName, State) -> - ssl_connection:handle_call(Event, From, StateName, State, ?MODULE). - -handle_common_event(internal, #alert{} = Alert, StateName, - #state{negotiated_version = Version} = State) -> - ssl_connection:handle_own_alert(Alert, Version, StateName, State); -%%% DTLS record protocol level handshake messages -handle_common_event(internal, #ssl_tls{type = ?HANDSHAKE, - fragment = Data}, - StateName, - #state{protocol_buffers = Buffers0, - negotiated_version = Version} = State0) -> - try - case dtls_handshake:get_dtls_handshake(Version, Data, Buffers0) of - {[], 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), - {next_state, StateName, - State#state{unprocessed_handshake_events = unprocessed_events(Events)}, Events} - end - catch throw:#alert{} = Alert -> - ssl_connection:handle_own_alert(Alert, Version, StateName, State0) - end; -%%% DTLS record protocol level application data messages -handle_common_event(internal, #ssl_tls{type = ?APPLICATION_DATA, fragment = Data}, StateName, State) -> - {next_state, StateName, State, [{next_event, internal, {application_data, Data}}]}; -%%% DTLS record protocol level change cipher messages -handle_common_event(internal, #ssl_tls{type = ?CHANGE_CIPHER_SPEC, fragment = Data}, StateName, State) -> - {next_state, StateName, State, [{next_event, internal, #change_cipher_spec{type = Data}}]}; -%%% DTLS record protocol level Alert messages -handle_common_event(internal, #ssl_tls{type = ?ALERT, fragment = EncAlerts}, StateName, - #state{negotiated_version = Version} = State) -> - case decode_alerts(EncAlerts) of - Alerts = [_|_] -> - handle_alerts(Alerts, {next_state, StateName, State}); - #alert{} = Alert -> - ssl_connection:handle_own_alert(Alert, Version, StateName, State) - end; -%% Ignore unknown TLS record level protocol messages -handle_common_event(internal, #ssl_tls{type = _Unknown}, StateName, State) -> - {next_state, StateName, State}. - -handle_state_timeout(flight_retransmission_timeout, StateName, - #state{flight_state = {retransmit, NextTimeout}} = State0) -> - {State1, Actions} = send_handshake_flight(State0#state{flight_state = {retransmit, NextTimeout}}, - retransmit_epoch(StateName, State0)), - {Record, State} = next_record(State1), - next_event(StateName, Record, State, Actions). - -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 -%% necessary cleaning up. When it returns, the gen_fsm terminates with -%% Reason. The return value is ignored. +%% gen_statem callbacks %%-------------------------------------------------------------------- +callback_mode() -> + [state_functions, state_enter]. + terminate(Reason, StateName, State) -> ssl_connection:terminate(Reason, StateName, State). -%%-------------------------------------------------------------------- -%% code_change(OldVsn, StateName, State, Extra) -> {ok, StateName, NewState} -%% Description: Convert process state when code is changed -%%-------------------------------------------------------------------- code_change(_OldVsn, StateName, State, _Extra) -> {ok, StateName, State}. @@ -552,55 +718,6 @@ 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, - - 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, 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_change_cipher(#change_cipher_spec{}, Version, Epoch, ConnectionStates) -> - dtls_record:encode_change_cipher_spec(Version, Epoch, ConnectionStates). - -encode_data(Data, Version, ConnectionStates0)-> - dtls_record:encode_data(Data, Version, ConnectionStates0). - -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, {CbModule, DataTag, CloseTag, ErrorTag}) -> #ssl_options{beast_mitigation = BeastMitigation} = SSLOptions, @@ -641,10 +758,12 @@ initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions, _}, User, flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT} }. -next_dtls_record(Data, #state{protocol_buffers = #protocol_buffers{ +next_dtls_record(Data, StateName, #state{protocol_buffers = #protocol_buffers{ dtls_record_buffer = Buf0, dtls_cipher_texts = CT0} = Buffers} = State0) -> - case dtls_record:get_dtls_records(Data, Buf0) of + case dtls_record:get_dtls_records(Data, + acceptable_record_versions(StateName, State0), + Buf0) of {Records, Buf1} -> CT1 = CT0 ++ Records, next_record(State0#state{protocol_buffers = @@ -654,13 +773,18 @@ next_dtls_record(Data, #state{protocol_buffers = #protocol_buffers{ Alert end. -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) -> +acceptable_record_versions(hello, _) -> + [dtls_record:protocol_version(Vsn) || Vsn <- ?ALL_DATAGRAM_SUPPORTED_VERSIONS]; +acceptable_record_versions(_, #state{negotiated_version = Version}) -> + [Version]. + +dtls_handshake_events(Packets) -> + lists:map(fun(Packet) -> + {next_event, internal, {handshake, Packet}} + end, Packets). + +decode_cipher_text(#state{protocol_buffers = #protocol_buffers{dtls_cipher_texts = [ CT | Rest]} = Buffers, + connection_states = ConnStates0} = State) -> case dtls_record:decode_cipher_text(CT, ConnStates0) of {Plain, ConnStates} -> {Plain, State#state{protocol_buffers = @@ -668,83 +792,185 @@ next_record(#state{protocol_buffers = connection_states = ConnStates}}; #alert{} = Alert -> {Alert, State} - end; -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}. + end. -next_record_if_active(State = - #state{socket_options = - #socket_options{active = false}}) -> - {no_record ,State}; +dtls_version(hello, Version, #state{role = server} = State) -> + State#state{negotiated_version = Version}; %%Inital version +dtls_version(_,_, State) -> + State. -next_record_if_active(State) -> - next_record(State). +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 -> + handle_own_alert(Alert, ClientVersion, hello, State0); + {Version, {Type, Session}, + ConnectionStates, Protocol0, ServerHelloExt, HashSign} -> + Protocol = case Protocol0 of + undefined -> CurrentProtocol; + _ -> Protocol0 + end, -passive_receive(State0 = #state{user_data_buffer = Buffer}, StateName) -> - case Buffer of - <<>> -> - {Record, State} = next_record(State0), - next_event(StateName, Record, State); - _ -> - {Record, State} = ssl_connection:read_application_data(<<>>, State0), - next_event(StateName, Record, State) + State = prepare_flight(State0#state{connection_states = ConnectionStates, + negotiated_version = Version, + hashsign_algorithm = HashSign, + client_hello_version = ClientVersion, + session = Session, + negotiated_protocol = Protocol}), + + ssl_connection:hello(internal, {common_client_hello, Type, ServerHelloExt}, + State, ?MODULE) end. -next_event(StateName, Record, State) -> - next_event(StateName, Record, State, []). -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{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, MoreActions} = send_handshake_flight(State1, Epoch), - {next_state, StateName, State, Actions ++ MoreActions}; - {#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{connection_states = #{current_read := #{epoch := CurrentEpoch}}} = State, Actions) -> - case Record of - no_record -> - {next_state, StateName, State, 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}; +%% raw data from socket, unpack records +handle_info({Protocol, _, _, _, Data}, StateName, + #state{data_tag = Protocol} = State0) -> + case next_dtls_record(Data, StateName, State0) of + {Record, State} -> + next_event(StateName, Record, State); #alert{} = Alert -> - {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} + ssl_connection:handle_normal_shutdown(Alert, StateName, State0), + {stop, {shutdown, own_alert}} + end; +handle_info({CloseTag, Socket}, StateName, + #state{socket = Socket, + socket_options = #socket_options{active = Active}, + protocol_buffers = #protocol_buffers{dtls_cipher_texts = CTs}, + close_tag = CloseTag, + negotiated_version = Version} = State) -> + %% Note that as of DTLS 1.2 (TLS 1.1), + %% failure to properly close a connection no longer requires that a + %% session not be resumed. This is a change from DTLS 1.0 to conform + %% with widespread implementation practice. + case (Active == false) andalso (CTs =/= []) of + false -> + case Version of + {254, N} when N =< 253 -> + ok; + _ -> + %% As invalidate_sessions here causes performance issues, + %% we will conform to the widespread implementation + %% practice and go aginst the spec + %%invalidate_session(Role, Host, Port, Session) + ok + end, + ssl_connection:handle_normal_shutdown(?ALERT_REC(?FATAL, ?CLOSE_NOTIFY), StateName, State), + {stop, {shutdown, transport_closed}}; + true -> + %% Fixes non-delivery of final DTLS record in {active, once}. + %% Basically allows the application the opportunity to set {active, once} again + %% and then receive the final message. + next_event(StateName, no_record, State) + end; + +handle_info(new_cookie_secret, StateName, + #state{protocol_specific = #{current_cookie_secret := Secret} = CookieInfo} = State) -> + erlang:send_after(dtls_v1:cookie_timeout(), self(), new_cookie_secret), + {next_state, StateName, State#state{protocol_specific = + CookieInfo#{current_cookie_secret => dtls_v1:cookie_secret(), + previous_cookie_secret => Secret}}}; +handle_info(Msg, StateName, State) -> + ssl_connection:StateName(info, Msg, State, ?MODULE). + +handle_state_timeout(flight_retransmission_timeout, StateName, + #state{flight_state = {retransmit, NextTimeout}} = State0) -> + {State1, Actions0} = send_handshake_flight(State0#state{flight_state = {retransmit, NextTimeout}}, + retransmit_epoch(StateName, State0)), + {Record, State2} = next_record(State1), + {next_state, StateName, State, Actions} = next_event(StateName, Record, State2, Actions0), + %% This will reset the retransmission timer by repeating the enter state event + {repeat_state, State, Actions}. + +handle_alerts([], Result) -> + Result; +handle_alerts(_, {stop,_} = Stop) -> + Stop; +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)). + +handle_own_alert(Alert, Version, StateName, #state{transport_cb = gen_udp, + role = Role, + ssl_options = Options} = State0) -> + case ignore_alert(Alert, State0) of + {true, State} -> + log_ignore_alert(Options#ssl_options.log_alert, StateName, Alert, Role), + {next_state, StateName, State}; + {false, State} -> + ssl_connection:handle_own_alert(Alert, Version, StateName, State) + end; +handle_own_alert(Alert, Version, StateName, State) -> + ssl_connection:handle_own_alert(Alert, Version, StateName, State). + +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_change_cipher(#change_cipher_spec{}, Version, Epoch, ConnectionStates) -> + dtls_record:encode_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. -dtls_version(hello, Version, #state{role = server} = State) -> - State#state{negotiated_version = Version}; %%Inital version -dtls_version(_,_, State) -> - State. +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 + %% 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. +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). prepare_flight(#state{flight_buffer = Flight, connection_states = ConnectionStates0, protocol_buffers = @@ -765,14 +991,14 @@ next_flight(Flight) -> Flight#{handshakes => [], change_cipher_spec => undefined, handshakes_after_change_cipher_spec => []}. - -start_flight(#state{transport_cb = gen_udp, - flight_state = {retransmit, Timeout}} = State) -> + +handle_flight_timer(#state{transport_cb = gen_udp, + flight_state = {retransmit, Timeout}} = State) -> start_retransmision_timer(Timeout, State); -start_flight(#state{transport_cb = gen_udp, +handle_flight_timer(#state{transport_cb = gen_udp, flight_state = connection} = State) -> {State, []}; -start_flight(State) -> +handle_flight_timer(State) -> %% No retransmision needed i.e DTLS over SCTP {State#state{flight_state = reliable}, []}. @@ -785,57 +1011,101 @@ new_timeout(N) when N =< 30 -> new_timeout(_) -> 60. -dtls_handshake_events(Packets) -> - lists:map(fun(Packet) -> - {next_event, internal, {handshake, Packet}} - end, Packets). +send_handshake_flight(#state{socket = Socket, + transport_cb = Transport, + 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(lists:reverse(Flight), Version, 1400, Epoch, ConnectionStates0), + send(Transport, Socket, Encoded), + {State0#state{connection_states = ConnectionStates}, []}; -renegotiate(#state{role = client} = State, Actions) -> - %% Handle same way as if server requested - %% the renegotiation - Hs0 = ssl_handshake:init_handshake_history(), - {next_state, connection, State#state{tls_handshake_history = Hs0, - protocol_buffers = #protocol_buffers{}}, - [{next_event, internal, #hello_request{}} | Actions]}; +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), -renegotiate(#state{role = server, - connection_states = CS0} = State0, Actions) -> - HelloRequest = ssl_handshake:hello_request(), - CS = CS0#{write_msg_seq => 0}, - {State1, MoreActions} = send_handshake(HelloRequest, - State0#state{connection_states = - CS}), - Hs0 = ssl_handshake:init_handshake_history(), - {Record, State} = next_record(State1#state{tls_handshake_history = Hs0, - protocol_buffers = #protocol_buffers{}}), - next_event(hello, Record, State, Actions ++ MoreActions). + send(Transport, Socket, [HsBefore, EncChangeCipher]), + {State0#state{connection_states = ConnectionStates}, []}; -handle_alerts([], Result) -> - Result; -handle_alerts(_, {stop,_} = Stop) -> - Stop; -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)). +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]), + {State0#state{connection_states = ConnectionStates}, []}; + +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]), + {State0#state{connection_states = ConnectionStates}, []}. retransmit_epoch(_StateName, #state{connection_states = ConnectionStates}) -> #{epoch := Epoch} = ssl_record:current_connection_state(ConnectionStates, write), Epoch. - -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. - +ignore_alert(#alert{level = ?FATAL}, #state{protocol_specific = #{ignored_alerts := N, + max_ignored_alerts := N}} = State) -> + {false, State}; +ignore_alert(#alert{level = ?FATAL} = Alert, + #state{protocol_specific = #{ignored_alerts := N} = PS} = State) -> + case is_ignore_alert(Alert) of + true -> + {true, State#state{protocol_specific = PS#{ignored_alerts => N+1}}}; + false -> + {false, State} + end; +ignore_alert(_, State) -> + {false, State}. + +%% RFC 6347 4.1.2.7. Handling Invalid Records +%% recommends to silently ignore invalid DTLS records when +%% upd is the transport. Note we do not support compression so no need +%% include ?DECOMPRESSION_FAILURE +is_ignore_alert(#alert{description = ?BAD_RECORD_MAC}) -> + true; +is_ignore_alert(#alert{description = ?RECORD_OVERFLOW}) -> + true; +is_ignore_alert(#alert{description = ?DECODE_ERROR}) -> + true; +is_ignore_alert(#alert{description = ?DECRYPT_ERROR}) -> + true; +is_ignore_alert(#alert{description = ?ILLEGAL_PARAMETER}) -> + true; +is_ignore_alert(_) -> + false. + +log_ignore_alert(true, StateName, Alert, Role) -> + Txt = ssl_alert:alert_txt(Alert), + error_logger:format("DTLS over UDP ~p: In state ~p ignored to send ALERT ~s as DoS-attack mitigation \n", + [Role, StateName, Txt]); +log_ignore_alert(false, _, _,_) -> + ok. |