diff options
Diffstat (limited to 'lib/ssl/src/dtls_connection.erl')
| -rw-r--r-- | lib/ssl/src/dtls_connection.erl | 967 |
1 files changed, 637 insertions, 330 deletions
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl index e490de7eeb..745db788e7 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 2013-2017. 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. @@ -21,7 +21,7 @@ %% Internal application API --behaviour(gen_fsm). +-behaviour(gen_statem). -include("dtls_connection.hrl"). -include("dtls_handshake.hrl"). @@ -36,62 +36,42 @@ %% Internal application API %% Setup --export([start_fsm/8]). +-export([start_fsm/8, start_link/7, init/1]). %% State transition handling --export([next_record/1, next_state/4%, - %%next_state_connection/2 - ]). +-export([next_record/1, next_event/3, next_event/4]). %% Handshake handling --export([%%renegotiate/1, - send_handshake/2, send_change_cipher/2]). +-export([renegotiate/2, + reinit_handshake_data/1, + send_handshake/2, queue_handshake/2, queue_change_cipher/2, + select_sni_extension/1]). %% Alert and close handling --export([send_alert/2, handle_own_alert/4, %%handle_close_alert/3, - handle_normal_shutdown/3 - %%handle_unexpected_message/3, - %%alert_user/5, alert_user/8 - ]). +-export([encode_alert/3,send_alert/2, close/5]). %% Data handling --export([%%write_application_data/3, - read_application_data/2%%, -%% passive_receive/2, next_record_if_active/1 - ]). -%% Called by tls_connection_sup --export([start_link/7]). +-export([encode_data/3, passive_receive/2, next_record_if_active/1, handle_common_event/4, + send/3, socket/5]). -%% gen_fsm callbacks --export([init/1, hello/2, certify/2, cipher/2, - abbreviated/2, connection/2, handle_event/3, - handle_sync_event/4, handle_info/3, terminate/3, code_change/4]). +%% gen_statem state functions +-export([init/3, error/3, downgrade/3, %% Initiation and take down states + hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states + connection/3]). +%% gen_statem callbacks +-export([callback_mode/0, terminate/3, code_change/4, format_status/2]). %%==================================================================== %% Internal application API %%==================================================================== -start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = false},_} = Opts, +start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = false},_, Tracker} = Opts, User, {CbModule, _,_, _} = CbInfo, Timeout) -> try {ok, Pid} = dtls_connection_sup:start_child([Role, Host, Port, Socket, Opts, User, CbInfo]), - {ok, SslSocket} = ssl_connection:socket_control(?MODULE, Socket, Pid, CbModule), - ok = ssl_connection:handshake(SslSocket, Timeout), - {ok, SslSocket} - catch - error:{badmatch, {error, _} = Error} -> - Error - end; - -start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = true},_} = Opts, - User, {CbModule, _,_, _} = CbInfo, - Timeout) -> - try - {ok, Pid} = dtls_connection_sup:start_child_dist([Role, Host, Port, Socket, - Opts, User, CbInfo]), - {ok, SslSocket} = ssl_connection:socket_control(?MODULE, Socket, Pid, CbModule), + {ok, SslSocket} = ssl_connection:socket_control(?MODULE, Socket, Pid, CbModule, Tracker), ok = ssl_connection:handshake(SslSocket, Timeout), {ok, SslSocket} catch @@ -99,32 +79,129 @@ start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = true},_} = Opts, Error end. -send_handshake(Handshake, #state{negotiated_version = Version, - tls_handshake_history = Hist0, - connection_states = ConnectionStates0} = State0) -> - {BinHandshake, ConnectionStates, Hist} = - encode_handshake(Handshake, Version, ConnectionStates0, Hist0), - send_flight(BinHandshake, State0#state{connection_states = ConnectionStates, - tls_handshake_history = Hist - }). +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}. + + +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} = - ssl_alert:encode(Alert, Version, ConnectionStates0), - Transport:send(Socket, BinMsg), + encode_alert(Alert, Version, ConnectionStates0), + send(Transport, Socket, BinMsg), State0#state{connection_states = ConnectionStates}. -send_change_cipher(Msg, #state{connection_states = ConnectionStates0, - socket = Socket, - negotiated_version = Version, - transport_cb = Transport} = State0) -> - {BinChangeCipher, ConnectionStates} = - encode_change_cipher(Msg, Version, ConnectionStates0), - Transport:send(Socket, BinChangeCipher), - 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 = + 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; +select_sni_extension(_) -> + undefined. + +socket(Pid, Transport, Socket, Connection, _) -> + dtls_socket:socket(Pid, Transport, Socket, Connection). %%==================================================================== %% tls_connection_sup API @@ -132,7 +209,7 @@ send_change_cipher(Msg, #state{connection_states = ConnectionStates0, %%-------------------------------------------------------------------- -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 @@ -141,83 +218,121 @@ send_change_cipher(Msg, #state{connection_states = ConnectionStates0, 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, {SSLOpts0, _} = 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), - Handshake = ssl_handshake:init_handshake_history(), - TimeStamp = erlang:monotonic_time(), - try ssl_config:init(SSLOpts0, Role) of - {ok, Ref, CertDbHandle, FileRefHandle, CacheHandle, CRLDbInfo, OwnCert, Key, DHParams} -> - Session = State0#state.session, - State = State0#state{ - tls_handshake_history = Handshake, - session = Session#session{own_certificate = OwnCert, - time_stamp = TimeStamp}, - file_ref_db = FileRefHandle, - cert_db_ref = Ref, - cert_db = CertDbHandle, - crl_db = CRLDbInfo, - session_cache = CacheHandle, - private_key = Key, - diffie_hellman_params = DHParams}, - gen_fsm:enter_loop(?MODULE, [], hello, State, get_timeout(State)) + try + State = ssl_connection:ssl_config(State0#state.ssl_options, Role, State0), + gen_statem:enter_loop(?MODULE, [], init, State) catch throw:Error -> - gen_fsm:enter_loop(?MODULE, [], error, {Error,State0}, get_timeout(State0)) + gen_statem:enter_loop(?MODULE, [], error, {Error,State0}) end. +callback_mode() -> + state_functions. + %%-------------------------------------------------------------------- -%% Description:There should be one instance of this function for each -%% possible state name. Whenever a gen_fsm receives an event sent -%% using gen_fsm:send_event/2, the instance of this function with the -%% same name as the current state name StateName is called to handle -%% the event. It is also called if a timeout occurs. -%% -hello(start, #state{host = Host, port = Port, role = client, - ssl_options = SslOpts, - session = #session{own_certificate = Cert} = Session0, - session_cache = Cache, session_cache_cb = CacheCb, - transport_cb = Transport, socket = Socket, - connection_states = ConnectionStates0, - renegotiation = {Renegotiation, _}} = State0) -> +%% State functions +%%-------------------------------------------------------------------- + +init({call, From}, {start, Timeout}, + #state{host = Host, port = Port, role = client, + ssl_options = SslOpts, + session = #session{own_certificate = Cert} = Session0, + connection_states = ConnectionStates0, + renegotiation = {Renegotiation, _}, + session_cache = Cache, + session_cache_cb = CacheCb + } = State0) -> + Timer = ssl_connection:start_or_recv_cancel_timer(Timeout, From), Hello = dtls_handshake:client_hello(Host, Port, ConnectionStates0, SslOpts, Cache, CacheCb, Renegotiation, Cert), - + Version = Hello#client_hello.client_version, - Handshake0 = ssl_handshake:init_handshake_history(), - {BinMsg, ConnectionStates, Handshake} = - encode_handshake(Hello, Version, ConnectionStates0, Handshake0), - Transport:send(Socket, BinMsg), - State1 = State0#state{connection_states = ConnectionStates, - negotiated_version = Version, %% Requested version + HelloVersion = dtls_record:lowest_protocol_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 session = Session0#session{session_id = Hello#client_hello.session_id}, - tls_handshake_history = Handshake}, - {Record, State} = next_record(State1), - next_state(hello, hello, Record, State); - -hello(Hello = #client_hello{client_version = ClientVersion}, - State = #state{connection_states = ConnectionStates0, - port = Port, session = #session{own_certificate = Cert} = Session0, - renegotiation = {Renegotiation, _}, - session_cache = Cache, - session_cache_cb = CacheCb, - ssl_options = SslOpts}) -> - case dtls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb, - ConnectionStates0, Cert}, Renegotiation) of - {Version, {Type, Session}, - ConnectionStates, - #hello_extensions{ec_point_formats = EcPointFormats, - elliptic_curves = EllipticCurves} = ServerHelloExt, HashSign} -> - ssl_connection:hello({common_client_hello, Type, ServerHelloExt, HashSign}, - State#state{connection_states = ConnectionStates, - negotiated_version = Version, - session = Session, - client_ecc = {EllipticCurves, EcPointFormats}}, ?MODULE); - #alert{} = Alert -> - handle_own_alert(Alert, ClientVersion, hello, State) + start_or_recv_from = From, + timer = Timer, + flight_state = {retransmit, ?INITIAL_RETRANSMIT_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); +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). + +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(_, _, _) -> + {keep_state_and_data, [postpone]}. + +%%-------------------------------------------------------------------- +-spec hello(gen_statem:event_type(), + #hello_request{} | #client_hello{} | #server_hello{} | term(), + #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +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, 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); +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(Hello, +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, Actions} = 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, Actions); +hello(internal, #server_hello{} = Hello, #state{connection_states = ConnectionStates0, negotiated_version = ReqVersion, role = client, @@ -225,25 +340,70 @@ hello(Hello, ssl_options = SslOptions} = State) -> case dtls_handshake:hello(Hello, SslOptions, ConnectionStates0, Renegotiation) of #alert{} = Alert -> - handle_own_alert(Alert, ReqVersion, hello, State); + ssl_connection:handle_own_alert(Alert, ReqVersion, hello, State); {Version, NewId, ConnectionStates, ProtoExt, Protocol} -> ssl_connection:handle_session(Hello, Version, NewId, ConnectionStates, ProtoExt, Protocol, State) end; - -hello(Msg, State) -> - ssl_connection:hello(Msg, State, ?MODULE). - -abbreviated(Msg, State) -> - ssl_connection:abbreviated(Msg, State, ?MODULE). - -certify(Msg, State) -> - ssl_connection:certify(Msg, State, ?MODULE). - -cipher(Msg, State) -> - ssl_connection:cipher(Msg, State, ?MODULE). - -connection(#hello_request{}, #state{host = Host, port = Port, +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(state_timeout, Event, State) -> + handle_state_timeout(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:abbreviated(Type, Event, + prepare_flight(State#state{connection_states = ConnectionStates, + flight_state = connection}), ?MODULE); +abbreviated(state_timeout, Event, State) -> + handle_state_timeout(Event, abbreviated, State); +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(state_timeout, Event, State) -> + handle_state_timeout(Event, certify, State); +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, + flight_state = connection}), + ?MODULE); +cipher(state_timeout, Event, State) -> + handle_state_timeout(Event, cipher, State); +cipher(Type, Event, State) -> + ssl_connection:cipher(Type, Event, State, ?MODULE). + +connection(info, Event, State) -> + handle_info(Event, connection, 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, @@ -251,46 +411,30 @@ connection(#hello_request{}, #state{host = Host, port = Port, renegotiation = {Renegotiation, _}} = State0) -> Hello = dtls_handshake:client_hello(Host, Port, ConnectionStates0, SslOpts, Cache, CacheCb, Renegotiation, Cert), - %% TODO DTLS version State1 = send_handshake(Hello, State0), - State1 = State0, + {State1, Actions} = send_handshake(Hello, State0), {Record, State} = next_record( State1#state{session = Session0#session{session_id = Hello#client_hello.session_id}}), - next_state(connection, hello, Record, State); - -connection(#client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) -> + next_event(hello, Record, State, Actions); +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 %% http://www.thc.org/thc-ssl-dos/ Rather than disabling client %% initiated renegotiation we will disallow many client initiated %% renegotiations immediately after each other. erlang:send_after(?WAIT_TO_ALLOW_RENEGOTIATION, self(), allow_renegotiate), - hello(Hello, State#state{allow_renegotiate = false}); - -connection(#client_hello{}, #state{role = server, allow_renegotiate = false} = State0) -> + {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), - State = send_alert(Alert, State0), - next_state_connection(connection, State); - -connection(Msg, State) -> - ssl_connection:connection(Msg, State, tls_connection). + 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). -%%-------------------------------------------------------------------- -%% Description: Whenever a gen_fsm receives an event sent using -%% gen_fsm:send_all_state_event/2, this function is called to handle -%% the event. Not currently used! -%%-------------------------------------------------------------------- -handle_event(_Event, StateName, State) -> - {next_state, StateName, State, get_timeout(State)}. - -%%-------------------------------------------------------------------- -%% Description: Whenever a gen_fsm receives an event sent using -%% gen_fsm:sync_send_all_state_event/2,3, this function is called to handle -%% the event. -%%-------------------------------------------------------------------- -handle_sync_event(Event, From, StateName, State) -> - ssl_connection:handle_sync_event(Event, From, StateName, State). +downgrade(Type, Event, State) -> + ssl_connection:downgrade(Type, Event, State, ?MODULE). %%-------------------------------------------------------------------- %% Description: This function is called by a gen_fsm when it receives any @@ -299,28 +443,93 @@ handle_sync_event(Event, From, StateName, State) -> %%-------------------------------------------------------------------- %% raw data from socket, unpack records -handle_info({Protocol, _, Data}, StateName, +handle_info({Protocol, _, _, _, Data}, StateName, #state{data_tag = Protocol} = State0) -> - %% Simplify for now to avoid dialzer warnings before implementation is compleate - %% case next_tls_record(Data, State0) of - %% {Record, State} -> - %% next_state(StateName, StateName, Record, State); - %% #alert{} = Alert -> - %% handle_normal_shutdown(Alert, StateName, State0), - %% {stop, {shutdown, own_alert}, State0} - %% end; - {Record, State} = next_tls_record(Data, State0), - next_state(StateName, StateName, Record, State); - + 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) -> - handle_normal_shutdown(?ALERT_REC(?FATAL, ?CLOSE_NOTIFY), StateName, State), - {stop, {shutdown, transport_closed}, State}; - + #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 @@ -337,152 +546,65 @@ terminate(Reason, StateName, State) -> code_change(_OldVsn, StateName, State, _Extra) -> {ok, StateName, State}. +format_status(Type, Data) -> + ssl_connection:format_status(Type, Data). + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- -encode_handshake(Handshake, Version, ConnectionStates0, Hist0) -> - Seq = sequence(ConnectionStates0), - {EncHandshake, FragmentedHandshake} = dtls_handshake:encode_handshake(Handshake, Version, - Seq), - Hist = ssl_handshake:update_handshake_history(Hist0, EncHandshake), - {Encoded, ConnectionStates} = - dtls_record:encode_handshake(FragmentedHandshake, - Version, ConnectionStates0), - {Encoded, ConnectionStates, Hist}. - -next_record(#state{%%flight = #flight{state = finished}, - protocol_buffers = - #protocol_buffers{dtls_packets = [], 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 = - Buffers#protocol_buffers{dtls_cipher_texts = Rest}, - connection_states = ConnStates}}; +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 -> - {Alert, State} - end; -next_record(#state{socket = Socket, - transport_cb = Transport} = State) -> %% when FlightState =/= finished - ssl_socket:setopts(Transport, Socket, [{active,once}]), - {no_record, State}; - - -next_record(State) -> - {no_record, State}. - -next_state(Current,_, #alert{} = Alert, #state{negotiated_version = Version} = State) -> - handle_own_alert(Alert, Version, Current, State); - -next_state(_,Next, no_record, State) -> - {next_state, Next, State, get_timeout(State)}; - -%% next_state(_,Next, #ssl_tls{type = ?ALERT, fragment = EncAlerts}, State) -> -%% Alerts = decode_alerts(EncAlerts), -%% handle_alerts(Alerts, {next_state, Next, State, get_timeout(State)}); - -next_state(Current, Next, #ssl_tls{type = ?HANDSHAKE, fragment = Data}, - State0 = #state{protocol_buffers = - #protocol_buffers{dtls_handshake_buffer = Buf0} = Buffers, - negotiated_version = Version}) -> - Handle = - fun({#hello_request{} = Packet, _}, {next_state, connection = SName, State}) -> - %% This message should not be included in handshake - %% message hashes. Starts new handshake (renegotiation) - Hs0 = ssl_handshake:init_handshake_history(), - ?MODULE:SName(Packet, State#state{tls_handshake_history=Hs0, - renegotiation = {true, peer}}); - ({#hello_request{} = Packet, _}, {next_state, SName, State}) -> - %% This message should not be included in handshake - %% message hashes. Already in negotiation so it will be ignored! - ?MODULE:SName(Packet, State); - ({#client_hello{} = Packet, Raw}, {next_state, connection = SName, State}) -> - Version = Packet#client_hello.client_version, - Hs0 = ssl_handshake:init_handshake_history(), - Hs1 = ssl_handshake:update_handshake_history(Hs0, Raw), - ?MODULE:SName(Packet, State#state{tls_handshake_history=Hs1, - renegotiation = {true, peer}}); - ({Packet, Raw}, {next_state, SName, State = #state{tls_handshake_history=Hs0}}) -> - Hs1 = ssl_handshake:update_handshake_history(Hs0, Raw), - ?MODULE:SName(Packet, State#state{tls_handshake_history=Hs1}); - (_, StopState) -> StopState - end, - try - {Packets, Buf} = tls_handshake:get_tls_handshake(Version,Data,Buf0), - State = State0#state{protocol_buffers = - Buffers#protocol_buffers{dtls_packets = Packets, - dtls_handshake_buffer = Buf}}, - handle_dtls_handshake(Handle, Next, State) - catch throw:#alert{} = Alert -> - handle_own_alert(Alert, Version, Current, State0) - end; - -next_state(_, StateName, #ssl_tls{type = ?APPLICATION_DATA, fragment = Data}, State0) -> - %% Simplify for now to avoid dialzer warnings before implementation is compleate - %% case read_application_data(Data, State0) of - %% Stop = {stop,_,_} -> - %% Stop; - %% {Record, State} -> - %% next_state(StateName, StateName, Record, State) - %% end; - {Record, State} = read_application_data(Data, State0), - next_state(StateName, StateName, Record, State); - -next_state(Current, Next, #ssl_tls{type = ?CHANGE_CIPHER_SPEC, fragment = <<1>>} = - _ChangeCipher, - #state{connection_states = ConnectionStates0} = State0) -> - ConnectionStates1 = - ssl_record:activate_pending_connection_state(ConnectionStates0, read), - {Record, State} = next_record(State0#state{connection_states = ConnectionStates1}), - next_state(Current, Next, Record, State); -next_state(Current, Next, #ssl_tls{type = _Unknown}, State0) -> - %% Ignore unknown type - {Record, State} = next_record(State0), - next_state(Current, Next, Record, State). - -handle_dtls_handshake(Handle, StateName, - #state{protocol_buffers = - #protocol_buffers{dtls_packets = [Packet]} = Buffers} = State) -> - FsmReturn = {next_state, StateName, State#state{protocol_buffers = - Buffers#protocol_buffers{dtls_packets = []}}}, - Handle(Packet, FsmReturn); - -handle_dtls_handshake(Handle, StateName, - #state{protocol_buffers = - #protocol_buffers{dtls_packets = [Packet | Packets]} = Buffers} = - State0) -> - FsmReturn = {next_state, StateName, State0#state{protocol_buffers = - Buffers#protocol_buffers{dtls_packets = - Packets}}}, - case Handle(Packet, FsmReturn) of - {next_state, NextStateName, State, _Timeout} -> - handle_dtls_handshake(Handle, NextStateName, State); - {stop, _,_} = Stop -> - Stop + 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). -send_flight(Fragments, #state{transport_cb = Transport, socket = Socket, - protocol_buffers = _PBuffers} = State) -> - Transport:send(Socket, Fragments), - %% Start retransmission - %% State#state{protocol_buffers = - %% (PBuffers#protocol_buffers){ #flight{state = waiting}}}}. - State. +encode_change_cipher(#change_cipher_spec{}, Version, Epoch, ConnectionStates) -> + dtls_record:encode_change_cipher_spec(Version, Epoch, ConnectionStates). -handle_own_alert(_,_,_, State) -> %% Place holder - {stop, {shutdown, own_alert}, State}. +encode_data(Data, Version, ConnectionStates0)-> + dtls_record:encode_data(Data, Version, ConnectionStates0). -handle_normal_shutdown(_, _, _State) -> %% Place holder - ok. +encode_alert(#alert{} = Alert, Version, ConnectionStates) -> + dtls_record:encode_alert_record(Alert, Version, ConnectionStates). -encode_change_cipher(#change_cipher_spec{}, Version, ConnectionStates) -> - dtls_record:encode_change_cipher_spec(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}) -> - ConnectionStates = ssl_record:init_connection_states(Role), + #ssl_options{beast_mitigation = BeastMitigation} = SSLOptions, + ConnectionStates = dtls_record:init_connection_states(Role, BeastMitigation), SessionCacheCb = case application:get_env(ssl, session_cb) of {ok, Cb} when is_atom(Cb) -> @@ -514,21 +636,206 @@ initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions}, User, renegotiation = {false, first}, allow_renegotiate = SSLOptions#ssl_options.client_renegotiation, start_or_recv_from = undefined, - send_queue = queue:new(), - protocol_cb = ?MODULE + protocol_cb = ?MODULE, + flight_buffer = new_flight(), + flight_state = {retransmit, ?INITIAL_RETRANSMIT_TIMEOUT} }. -read_application_data(_,State) -> - {#ssl_tls{fragment = <<"place holder">>}, State}. - -next_tls_record(_, State) -> - {#ssl_tls{fragment = <<"place holder">>}, State}. -get_timeout(_) -> %% Place holder - infinity. +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 + {Records, Buf1} -> + CT1 = CT0 ++ Records, + next_record(State0#state{protocol_buffers = + Buffers#protocol_buffers{dtls_record_buffer = Buf1, + dtls_cipher_texts = CT1}}); + #alert{} = Alert -> + Alert + end. -next_state_connection(_, State) -> %% Place holder - {next_state, connection, State, get_timeout(State)}. +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 + {Plain, ConnStates} -> + {Plain, State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + 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}. + +next_record_if_active(State = + #state{socket_options = + #socket_options{active = false}}) -> + {no_record ,State}; + +next_record_if_active(State) -> + next_record(State). + +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_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}; + #alert{} = Alert -> + {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} + end. + +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, Timeout}} = State) -> + start_retransmision_timer(Timeout, State); +start_flight(#state{transport_cb = gen_udp, + flight_state = connection} = State) -> + {State, []}; +start_flight(State) -> + %% No retransmision needed i.e DTLS over SCTP + {State#state{flight_state = reliable}, []}. + +start_retransmision_timer(Timeout, State) -> + {State#state{flight_state = {retransmit, new_timeout(Timeout)}}, + [{state_timeout, Timeout, flight_retransmission_timeout}]}. + +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 + %% 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]}; + +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). + +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)). + +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. -sequence(_) -> - %%TODO real imp - 1. |