diff options
Diffstat (limited to 'lib/ssl/src/tls_connection.erl')
| -rw-r--r-- | lib/ssl/src/tls_connection.erl | 344 |
1 files changed, 290 insertions, 54 deletions
diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl index dfae13f6d7..a47caed410 100644 --- a/lib/ssl/src/tls_connection.erl +++ b/lib/ssl/src/tls_connection.erl @@ -37,7 +37,8 @@ -include("ssl_api.hrl"). -include("ssl_internal.hrl"). -include("ssl_srp.hrl"). --include_lib("public_key/include/public_key.hrl"). +-include_lib("public_key/include/public_key.hrl"). +-include_lib("kernel/include/logger.hrl"). %% Internal application API @@ -49,7 +50,8 @@ handle_protocol_record/3]). %% Handshake handling --export([renegotiation/2, renegotiate/2, send_handshake/2, +-export([renegotiation/2, renegotiate/2, send_handshake/2, + send_handshake_flight/1, queue_handshake/2, queue_change_cipher/2, reinit/1, reinit_handshake_data/1, select_sni_extension/1, empty_connection_state/2]). @@ -67,9 +69,26 @@ -export([init/3, error/3, downgrade/3, %% Initiation and take down states hello/3, user_hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states connection/3]). +%% TLS 1.3 state functions (server) +-export([start/3, %% common state with client + negotiated/3, + recvd_ch/3, + wait_cert/3, %% common state with client + wait_cv/3, %% common state with client + wait_eoed/3, + wait_finished/3, %% common state with client + wait_flight2/3, + connected/3 %% common state with client + ]). +%% TLS 1.3 state functions (client) +-export([wait_cert_cr/3, + wait_ee/3, + wait_sh/3 + ]). %% gen_statem callbacks -export([callback_mode/0, terminate/3, code_change/4, format_status/2]). +-export([encode_handshake/4]). -define(DIST_CNTRL_SPAWN_OPTS, [{priority, max}]). @@ -152,8 +171,9 @@ next_record(#state{protocol_buffers = #protocol_buffers{tls_cipher_texts = [#ssl_tls{type = Type}| _] = CipherTexts0} = Buffers, connection_states = ConnectionStates0, + connection_env = #connection_env{negotiated_version = Version}, ssl_options = #ssl_options{padding_check = Check}} = State) -> - case decode_cipher_texts(Type, CipherTexts0, ConnectionStates0, Check, <<>>) of + case decode_cipher_texts(Version, Type, CipherTexts0, ConnectionStates0, Check, <<>>) of {#ssl_tls{} = Record, ConnectionStates, CipherTexts} -> {Record, State#state{protocol_buffers = Buffers#protocol_buffers{tls_cipher_texts = CipherTexts}, connection_states = ConnectionStates}}; @@ -198,20 +218,20 @@ next_event(StateName, Record, State, Actions) -> {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} end. -decode_cipher_texts(Type, [] = CipherTexts, ConnectionStates, _, Acc) -> +decode_cipher_texts(_, Type, [] = CipherTexts, ConnectionStates, _, Acc) -> {#ssl_tls{type = Type, fragment = Acc}, ConnectionStates, CipherTexts}; -decode_cipher_texts(Type, +decode_cipher_texts(Version, Type, [#ssl_tls{type = Type} = CT | CipherTexts], ConnectionStates0, Check, Acc) -> - case tls_record:decode_cipher_text(CT, ConnectionStates0, Check) of + case tls_record:decode_cipher_text(Version, CT, ConnectionStates0, Check) of {#ssl_tls{type = ?APPLICATION_DATA, fragment = Plain}, ConnectionStates} -> - decode_cipher_texts(Type, CipherTexts, + decode_cipher_texts(Version, Type, CipherTexts, ConnectionStates, Check, <<Acc/binary, Plain/binary>>); - {#ssl_tls{type = Type, fragment = Plain}, ConnectionStates} -> - {#ssl_tls{type = Type, fragment = Plain}, ConnectionStates, CipherTexts}; + {#ssl_tls{type = Type0, fragment = Plain}, ConnectionStates} -> + {#ssl_tls{type = Type0, fragment = Plain}, ConnectionStates, CipherTexts}; #alert{} = Alert -> {Alert, ConnectionStates0, CipherTexts} end; -decode_cipher_texts(Type, CipherTexts, ConnectionStates, _, Acc) -> +decode_cipher_texts(_, Type, CipherTexts, ConnectionStates, _, Acc) -> {#ssl_tls{type = Type, fragment = Acc}, ConnectionStates, CipherTexts}. %%% TLS record protocol level application data messages @@ -231,7 +251,8 @@ handle_protocol_record(#ssl_tls{type = ?HANDSHAKE, fragment = Data}, connection_env = #connection_env{negotiated_version = Version}, ssl_options = Options} = State0) -> try - {Packets, Buf} = tls_handshake:get_tls_handshake(Version,Data,Buf0, Options), + EffectiveVersion = effective_version(Version, Options), + {Packets, Buf} = tls_handshake:get_tls_handshake(EffectiveVersion,Data,Buf0, Options), State = State0#state{protocol_buffers = Buffers#protocol_buffers{tls_handshake_buffer = Buf}}, @@ -312,12 +333,17 @@ renegotiate(#state{static_env = #static_env{role = server, send_handshake(Handshake, State) -> send_handshake_flight(queue_handshake(Handshake, State)). + queue_handshake(Handshake, #state{handshake_env = #handshake_env{tls_handshake_history = Hist0} = HsEnv, connection_env = #connection_env{negotiated_version = Version}, flight_buffer = Flight0, + ssl_options = SslOpts, connection_states = ConnectionStates0} = State0) -> {BinHandshake, ConnectionStates, Hist} = encode_handshake(Handshake, Version, ConnectionStates0, Hist0), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'handshake', Handshake), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'tls_record', BinHandshake), + State0#state{connection_states = ConnectionStates, handshake_env = HsEnv#handshake_env{tls_handshake_history = Hist}, flight_buffer = Flight0 ++ [BinHandshake]}. @@ -328,11 +354,14 @@ send_handshake_flight(#state{static_env = #static_env{socket = Socket, send(Transport, Socket, Flight), {State0#state{flight_buffer = []}, []}. + queue_change_cipher(Msg, #state{connection_env = #connection_env{negotiated_version = Version}, flight_buffer = Flight0, + ssl_options = SslOpts, connection_states = ConnectionStates0} = State0) -> {BinChangeCipher, ConnectionStates} = encode_change_cipher(Msg, Version, ConnectionStates0), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'tls_record', BinChangeCipher), State0#state{connection_states = ConnectionStates, flight_buffer = Flight0 ++ [BinChangeCipher]}. @@ -352,8 +381,8 @@ reinit_handshake_data(#state{handshake_env = HsEnv} =State) -> premaster_secret = undefined} }. -select_sni_extension(#client_hello{extensions = HelloExtensions}) -> - HelloExtensions#hello_extensions.sni; +select_sni_extension(#client_hello{extensions = #{sni := SNI}}) -> + SNI; select_sni_extension(_) -> undefined. @@ -363,6 +392,7 @@ empty_connection_state(ConnectionEnd, BeastMitigation) -> %%==================================================================== %% Alert and close handling %%==================================================================== + %%-------------------------------------------------------------------- -spec encode_alert(#alert{}, ssl_record:ssl_version(), ssl_record:connection_states()) -> {iolist(), ssl_record:connection_states()}. @@ -375,10 +405,12 @@ encode_alert(#alert{} = Alert, Version, ConnectionStates) -> send_alert(Alert, #state{static_env = #static_env{socket = Socket, transport_cb = Transport}, connection_env = #connection_env{negotiated_version = Version}, + ssl_options = SslOpts, connection_states = ConnectionStates0} = StateData0) -> {BinMsg, ConnectionStates} = encode_alert(Alert, Version, ConnectionStates0), send(Transport, Socket, BinMsg), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'tls_record', BinMsg), StateData0#state{connection_states = ConnectionStates}. %% If an ALERT sent in the connection state, should cause the TLS @@ -470,22 +502,27 @@ init({call, From}, {start, Timeout}, session = #session{own_certificate = Cert} = Session0, connection_states = ConnectionStates0 } = State0) -> + KeyShare = maybe_generate_client_shares(SslOpts), Hello = tls_handshake:client_hello(Host, Port, ConnectionStates0, SslOpts, - Cache, CacheCb, Renegotiation, Cert), - - Version = Hello#client_hello.client_version, - HelloVersion = tls_record:hello_version(Version, SslOpts#ssl_options.versions), + Cache, CacheCb, Renegotiation, Cert, KeyShare), + + HelloVersion = tls_record:hello_version(SslOpts#ssl_options.versions), Handshake0 = ssl_handshake:init_handshake_history(), {BinMsg, ConnectionStates, Handshake} = encode_handshake(Hello, HelloVersion, ConnectionStates0, Handshake0), send(Transport, Socket, BinMsg), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'handshake', Hello), + ssl_logger:debug(SslOpts#ssl_options.log_level, outbound, 'tls_record', BinMsg), + State = State0#state{connection_states = ConnectionStates, - connection_env = CEnv#connection_env{negotiated_version = Version}, %% Requested version + connection_env = CEnv#connection_env{negotiated_version = HelloVersion}, %% Requested version session = Session0#session{session_id = Hello#client_hello.session_id}, handshake_env = HsEnv#handshake_env{tls_handshake_history = Handshake}, - start_or_recv_from = From}, + start_or_recv_from = From, + key_share = KeyShare}, next_event(hello, no_record, State, [{{timeout, handshake}, Timeout, close}]); + init(Type, Event, State) -> gen_handshake(?FUNCTION_NAME, Type, Event, State). @@ -516,14 +553,15 @@ hello(internal, #client_hello{extensions = Extensions} = Hello, start_or_recv_from = From} = State) -> {next_state, user_hello, State#state{start_or_recv_from = undefined, handshake_env = HsEnv#handshake_env{hello = Hello}}, - [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]}; + [{reply, From, {ok, Extensions}}]}; hello(internal, #server_hello{extensions = Extensions} = Hello, #state{ssl_options = #ssl_options{handshake = hello}, handshake_env = HsEnv, start_or_recv_from = From} = State) -> {next_state, user_hello, State#state{start_or_recv_from = undefined, handshake_env = HsEnv#handshake_env{hello = Hello}}, - [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]}; + [{reply, From, {ok, Extensions}}]}; + hello(internal, #client_hello{client_version = ClientVersion} = Hello, #state{connection_states = ConnectionStates0, static_env = #static_env{ @@ -536,27 +574,40 @@ hello(internal, #client_hello{client_version = ClientVersion} = Hello, connection_env = CEnv, session = #session{own_certificate = Cert} = Session0, ssl_options = SslOpts} = State) -> - case tls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb, - ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of - #alert{} = Alert -> - ssl_connection:handle_own_alert(Alert, ClientVersion, hello, - State#state{connection_env = - CEnv#connection_env{negotiated_version = ClientVersion}}); - {Version, {Type, Session}, - ConnectionStates, Protocol0, ServerHelloExt, HashSign} -> - Protocol = case Protocol0 of - undefined -> CurrentProtocol; - _ -> Protocol0 - end, - gen_handshake(?FUNCTION_NAME, internal, {common_client_hello, Type, ServerHelloExt}, - State#state{connection_states = ConnectionStates, - connection_env = CEnv#connection_env{negotiated_version = Version}, - handshake_env = HsEnv#handshake_env{ - hashsign_algorithm = HashSign, - client_hello_version = ClientVersion, - negotiated_protocol = Protocol}, - session = Session - }) + + case choose_tls_version(SslOpts, Hello) of + 'tls_v1.3' -> + %% Continue in TLS 1.3 'start' state + {next_state, start, State, [{next_event, internal, Hello}]}; + 'tls_v1.2' -> + case tls_handshake:hello(Hello, + SslOpts, + {Port, Session0, Cache, CacheCb, + ConnectionStates0, Cert, KeyExAlg}, + Renegotiation) of + #alert{} = Alert -> + ssl_connection:handle_own_alert(Alert, ClientVersion, hello, + State#state{connection_env = #connection_env{negotiated_version + = ClientVersion}}); + {Version, {Type, Session}, + ConnectionStates, Protocol0, ServerHelloExt, HashSign} -> + Protocol = case Protocol0 of + undefined -> CurrentProtocol; + _ -> Protocol0 + end, + gen_handshake(?FUNCTION_NAME, + internal, + {common_client_hello, Type, ServerHelloExt}, + State#state{connection_states = ConnectionStates, + connection_env = CEnv#connection_env{negotiated_version = Version}, + handshake_env = HsEnv#handshake_env{ + hashsign_algorithm = HashSign, + client_hello_version = ClientVersion, + negotiated_protocol = Protocol}, + session = Session + }) + end + end; hello(internal, #server_hello{} = Hello, #state{connection_states = ConnectionStates0, @@ -661,7 +712,7 @@ connection(internal, #hello_request{}, try tls_sender:peer_renegotiate(Pid) of {ok, Write} -> Hello = tls_handshake:client_hello(Host, Port, ConnectionStates, SslOpts, - Cache, CacheCb, Renegotiation, Cert), + Cache, CacheCb, Renegotiation, Cert, undefined), {State, Actions} = send_handshake(Hello, State0#state{connection_states = ConnectionStates#{current_write => Write}}), next_event(hello, no_record, State#state{session = Session0#session{session_id = Hello#client_hello.session_id}}, Actions) @@ -680,7 +731,8 @@ connection(internal, #hello_request{}, ssl_options = SslOpts, connection_states = ConnectionStates} = State0) -> Hello = tls_handshake:client_hello(Host, Port, ConnectionStates, SslOpts, - Cache, CacheCb, Renegotiation, Cert), + Cache, CacheCb, Renegotiation, Cert, undefined), + {State, Actions} = send_handshake(Hello, State0), next_event(hello, no_record, State#state{session = Session0#session{session_id = Hello#client_hello.session_id}}, Actions); @@ -736,7 +788,119 @@ downgrade(info, {CloseTag, Socket}, downgrade(info, Info, State) -> handle_info(Info, ?FUNCTION_NAME, State); downgrade(Type, Event, State) -> - ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). + ssl_connection:?FUNCTION_NAME(Type, Event, State, ?MODULE). + +%%-------------------------------------------------------------------- +%% TLS 1.3 state functions +%%-------------------------------------------------------------------- +%%-------------------------------------------------------------------- +-spec start(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +start(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +start(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec negotiated(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +negotiated(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +negotiated(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec recvd_ch(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +recvd_ch(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +recvd_ch(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_cert(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_cert(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_cert(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_cv(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_cv(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_cv(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_eoed(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_eoed(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_eoed(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_finished(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_finished(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_finished(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_flight2(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_flight2(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_flight2(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec connected(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +connected(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +connected(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_cert_cr(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_cert_cr(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_cert_cr(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_ee(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_ee(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_ee(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + +%%-------------------------------------------------------------------- +-spec wait_sh(gen_statem:event_type(), term(), #state{}) -> + gen_statem:state_function_result(). +%%-------------------------------------------------------------------- +wait_sh(info, Event, State) -> + gen_info_1_3(Event, ?FUNCTION_NAME, State); +wait_sh(Type, Event, State) -> + gen_handshake_1_3(?FUNCTION_NAME, Type, Event, State). + %-------------------------------------------------------------------- %% gen_statem callbacks %%-------------------------------------------------------------------- @@ -767,7 +931,6 @@ initial_state(Role, Sender, Host, Port, Socket, {SSLOptions, SocketOptions, Trac #ssl_options{beast_mitigation = BeastMitigation, erl_dist = IsErlDist} = SSLOptions, ConnectionStates = tls_record:init_connection_states(Role, BeastMitigation), - SessionCacheCb = case application:get_env(ssl, session_cb) of {ok, Cb} when is_atom(Cb) -> Cb; @@ -824,8 +987,9 @@ initialize_tls_sender(#state{static_env = #static_env{ tracker = Tracker }, connection_env = #connection_env{negotiated_version = Version}, - socket_options = SockOpts, - ssl_options = #ssl_options{renegotiate_at = RenegotiateAt}, + socket_options = SockOpts, + ssl_options = #ssl_options{renegotiate_at = RenegotiateAt, + log_level = LogLevel}, connection_states = #{current_write := ConnectionWriteState}, protocol_specific = #{sender := Sender}}) -> Init = #{current_write => ConnectionWriteState, @@ -836,16 +1000,17 @@ initialize_tls_sender(#state{static_env = #static_env{ protocol_cb => Connection, transport_cb => Transport, negotiated_version => Version, - renegotiate_at => RenegotiateAt}, + renegotiate_at => RenegotiateAt, + log_level => LogLevel}, tls_sender:initialize(Sender, Init). next_tls_record(Data, StateName, #state{protocol_buffers = #protocol_buffers{tls_record_buffer = Buf0, - tls_cipher_texts = CT0} = Buffers} - = State0) -> - case tls_record:get_tls_records(Data, + tls_cipher_texts = CT0} = Buffers, + ssl_options = SslOpts} = State0) -> + case tls_record:get_tls_records(Data, acceptable_record_versions(StateName, State0), - Buf0) of + Buf0, SslOpts) of {Records, Buf1} -> CT1 = CT0 ++ Records, next_record(State0#state{protocol_buffers = @@ -855,7 +1020,10 @@ next_tls_record(Data, StateName, #state{protocol_buffers = handle_record_alert(Alert, State0) end. - +%% TLS 1.3 Client/Server +%% - Ignore TLSPlaintext.legacy_record_version +%% - Verify that TLSCiphertext.legacy_record_version is set to 0x0303 for all records +%% other than an initial ClientHello, where it MAY also be 0x0301. acceptable_record_versions(StateName, #state{connection_env = #connection_env{negotiated_version = Version}}) when StateName =/= hello-> Version; acceptable_record_versions(hello, _) -> @@ -968,6 +1136,20 @@ gen_handshake(StateName, Type, Event, Version, StateName, State) end. + +gen_handshake_1_3(StateName, Type, Event, + #state{connection_env = #connection_env{negotiated_version = Version}} = State) -> + try tls_connection_1_3: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. + + gen_info(Event, connection = StateName, #state{connection_env = #connection_env{negotiated_version = Version}} = State) -> try handle_info(Event, StateName, State) of Result -> @@ -989,6 +1171,29 @@ gen_info(Event, StateName, #state{connection_env = #connection_env{negotiated_ve malformed_handshake_data), Version, StateName, State) end. + +gen_info_1_3(Event, connected = StateName, #state{connection_env = #connection_env{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_1_3(Event, StateName, #state{connection_env = #connection_env{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 @@ -1033,3 +1238,34 @@ ensure_sender_terminate(_, #state{protocol_specific = #{sender := Sender}}) -> end end, spawn(Kill). + +maybe_generate_client_shares(#ssl_options{ + versions = [Version|_], + supported_groups = + #supported_groups{ + supported_groups = Groups}}) + when Version =:= {3,4} -> + ssl_cipher:generate_client_shares(Groups); +maybe_generate_client_shares(_) -> + undefined. + +choose_tls_version(#ssl_options{versions = Versions}, + #client_hello{ + extensions = #{client_hello_versions := + #client_hello_versions{versions = ClientVersions} + } + }) -> + case ssl_handshake:select_supported_version(ClientVersions, Versions) of + {3,4} -> + 'tls_v1.3'; + _Else -> + 'tls_v1.2' + end; +choose_tls_version(_, _) -> + 'tls_v1.2'. + + +effective_version(undefined, #ssl_options{versions = [Version|_]}) -> + Version; +effective_version(Version, _) -> + Version. |