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authorIngela Anderton Andin <[email protected]>2016-04-27 11:44:37 +0200
committerIngela Anderton Andin <[email protected]>2016-05-03 13:46:50 +0200
commit0f782eb6377ddd1e5673c186b8b1a37edd610e4b (patch)
tree6a6986d92f2c68b7ab05a73605ffbbf90d7a4e7e
parent67de1ba82d1af910dc6ab6d41a1f22dbfb39f658 (diff)
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ssl: Adapt DTLS to gen_statem
DTLS is not in working mode yet, but the gen_statem rewrite should make completion easier.
-rw-r--r--lib/ssl/src/dtls_connection.erl351
-rw-r--r--lib/ssl/src/dtls_record.erl25
2 files changed, 168 insertions, 208 deletions
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 2c9fe5cfb5..82d6faee42 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -36,37 +36,38 @@
%% 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]).
%% Handshake handling
--export([%%renegotiate/1,
+-export([%%renegotiate/2,
send_handshake/2, send_change_cipher/2]).
+
%% 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([%%send_alert/2, handle_own_alert/4, handle_close_alert/3,
+ handle_normal_shutdown/3 %%, close/5
+ %%alert_user/6, alert_user/9
]).
%% Data handling
-export([%%write_application_data/3,
- read_application_data/2%%,
-%% passive_receive/2, next_record_if_active/1
+ read_application_data/2,
+ %%passive_receive/2,
+ next_record_if_active/1 %%,
+ %%handle_common_event/4
]).
-%% Called by tls_connection_sup
--export([start_link/7]).
+%% 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([terminate/3, code_change/4, format_status/2]).
-%% 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]).
+-define(GEN_STATEM_CB_MODE, state_functions).
%%====================================================================
%% Internal application API
@@ -141,75 +142,74 @@ 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, [], ?GEN_STATEM_CB_MODE, init, State)
catch
throw:Error ->
- gen_fsm:enter_loop(?MODULE, [], error, {Error,State0}, get_timeout(State0))
+ gen_statem:enter_loop(?MODULE, [], ?GEN_STATEM_CB_MODE, error, {Error,State0})
end.
%%--------------------------------------------------------------------
-%% 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 functionsconnection/2
+%%--------------------------------------------------------------------
+
+init({call, From}, {start, Timeout},
+ #state{host = Host, port = Port, role = client,
+ ssl_options = SslOpts,
+ session = #session{own_certificate = Cert} = Session0,
+ transport_cb = Transport, socket = Socket,
+ connection_states = ConnectionStates0,
+ renegotiation = {Renegotiation, _},
+ session_cache = Cache,
+ 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),
+ Cache, CacheCb, Renegotiation, Cert),
Version = Hello#client_hello.client_version,
+ HelloVersion = dtls_record:lowest_protocol_version(SslOpts#ssl_options.versions),
Handshake0 = ssl_handshake:init_handshake_history(),
{BinMsg, ConnectionStates, Handshake} =
- encode_handshake(Hello, Version, ConnectionStates0, Handshake0),
+ encode_handshake(Hello, HelloVersion, ConnectionStates0, Handshake0),
Transport:send(Socket, BinMsg),
State1 = State0#state{connection_states = ConnectionStates,
negotiated_version = Version, %% Requested version
session =
Session0#session{session_id = Hello#client_hello.session_id},
- tls_handshake_history = Handshake},
+ tls_handshake_history = Handshake,
+ start_or_recv_from = From,
+ timer = Timer},
{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}) ->
+ next_event(hello, Record, State);
+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]}.
+
+hello(internal, #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,
+ ssl_options = SslOpts} = State) ->
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},
+ ssl_connection:hello(internal, {common_client_hello, Type, ServerHelloExt, HashSign},
State#state{connection_states = ConnectionStates,
negotiated_version = Version,
session = Session,
@@ -217,7 +217,7 @@ hello(Hello = #client_hello{client_version = ClientVersion},
#alert{} = Alert ->
handle_own_alert(Alert, ClientVersion, hello, State)
end;
-hello(Hello,
+hello(internal, Hello,
#state{connection_states = ConnectionStates0,
negotiated_version = ReqVersion,
role = client,
@@ -230,20 +230,30 @@ hello(Hello,
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(info, Event, State) ->
+ handle_info(Event, hello, State);
+
+hello(Type, Event, State) ->
+ ssl_connection:hello(Type, Event, State, ?MODULE).
+
+abbreviated(info, Event, State) ->
+ handle_info(Event, abbreviated, State);
+abbreviated(Type, Event, State) ->
+ ssl_connection:abbreviated(Type, Event, State, ?MODULE).
+
+certify(info, Event, State) ->
+ handle_info(Event, certify, State);
+certify(Type, Event, State) ->
+ ssl_connection:certify(Type, Event, State, ?MODULE).
+
+cipher(info, Event, State) ->
+ handle_info(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,
@@ -257,40 +267,30 @@ connection(#hello_request{}, #state{host = Host, port = Port,
next_record(
State1#state{session = Session0#session{session_id
= Hello#client_hello.session_id}}),
- next_state(connection, hello, Record, State);
+ next_event(hello, Record, State);
-connection(#client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) ->
+connection(internal, #client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) ->
%% Mitigate Computational DoS attack
%% http://www.educatedguesswork.org/2011/10/ssltls_and_computational_dos.html
%% 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});
+ {next_state, hello, State#state{allow_renegotiate = false}, [{next_event, internal, Hello}]};
+
-connection(#client_hello{}, #state{role = server, allow_renegotiate = false} = State0) ->
+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);
+ State1 = send_alert(Alert, State0),
+ {Record, State} = ssl_connection:prepare_connection(State1, ?MODULE),
+ next_event(connection, Record, State);
-connection(Msg, State) ->
- ssl_connection:connection(Msg, State, tls_connection).
+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)}.
+downgrade(Type, Event, State) ->
+ ssl_connection:downgrade(Type, Event, State, ?MODULE).
-%%--------------------------------------------------------------------
-%% 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).
%%--------------------------------------------------------------------
%% Description: This function is called by a gen_fsm when it receives any
@@ -301,26 +301,25 @@ handle_sync_event(Event, From, StateName, State) ->
%% raw data from socket, unpack records
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_tls_record(Data, State0) of
+ {Record, State} ->
+ next_event(StateName, Record, State);
+ #alert{} = Alert ->
+ 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};
+ {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).
+
%%--------------------------------------------------------------------
%% 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
@@ -335,7 +334,10 @@ terminate(Reason, StateName, State) ->
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, StateName, State, _Extra) ->
- {ok, StateName, State}.
+ {?GEN_STATEM_CB_MODE, StateName, State}.
+
+format_status(Type, Data) ->
+ ssl_connection:format_status(Type, Data).
%%--------------------------------------------------------------------
%%% Internal functions
@@ -372,96 +374,28 @@ next_record(#state{socket = Socket,
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
- end.
+next_event(StateName, Record, State) ->
+ next_event(StateName, Record, State, []).
+next_event(connection = StateName, no_record, State0, Actions) ->
+ case next_record_if_active(State0) of
+ {no_record, State} ->
+ ssl_connection:hibernate_after(StateName, State, Actions);
+ {#ssl_tls{} = Record, State} ->
+ {next_state, StateName, State, [{next_event, internal, {dtls_record, Record}} | Actions]};
+ {#alert{} = Alert, State} ->
+ {next_state, StateName, State, [{next_event, internal, Alert} | Actions]}
+ end;
+next_event(StateName, Record, State, Actions) ->
+ case Record of
+ no_record ->
+ {next_state, StateName, State, Actions};
+ #ssl_tls{} = Record ->
+ {next_state, StateName, State, [{next_event, internal, {dtls_record, Record}} | Actions]};
+ #alert{} = Alert ->
+ {next_state, StateName, State, [{next_event, internal, Alert} | Actions]}
+ end.
send_flight(Fragments, #state{transport_cb = Transport, socket = Socket,
protocol_buffers = _PBuffers} = State) ->
@@ -518,16 +452,19 @@ initial_state(Role, Host, Port, Socket, {SSLOptions, SocketOptions}, User,
}.
read_application_data(_,State) ->
{#ssl_tls{fragment = <<"place holder">>}, State}.
-
+
+next_tls_record(<<>>, _State) ->
+ #alert{}; %% Place holder
next_tls_record(_, State) ->
{#ssl_tls{fragment = <<"place holder">>}, State}.
-get_timeout(_) -> %% Place holder
- infinity.
-
-next_state_connection(_, State) -> %% Place holder
- {next_state, connection, State, get_timeout(State)}.
-
sequence(_) ->
%%TODO real imp
1.
+next_record_if_active(State =
+ #state{socket_options =
+ #socket_options{active = false}}) ->
+ {no_record ,State};
+
+next_record_if_active(State) ->
+ next_record(State).
diff --git a/lib/ssl/src/dtls_record.erl b/lib/ssl/src/dtls_record.erl
index 2530d66052..e79e1cede0 100644
--- a/lib/ssl/src/dtls_record.erl
+++ b/lib/ssl/src/dtls_record.erl
@@ -39,7 +39,7 @@
-export([encode_plain_text/4, encode_handshake/3, encode_change_cipher_spec/2]).
%% Protocol version handling
--export([protocol_version/1, lowest_protocol_version/2,
+-export([protocol_version/1, lowest_protocol_version/2, lowest_protocol_version/1,
highest_protocol_version/1, supported_protocol_versions/0,
is_acceptable_version/2]).
@@ -254,6 +254,18 @@ lowest_protocol_version(Version = {M,_}, {N, _}) when M > N ->
Version;
lowest_protocol_version(_,Version) ->
Version.
+
+%%--------------------------------------------------------------------
+-spec lowest_protocol_version([dtls_version()]) -> dtls_version().
+%%
+%% Description: Lowest protocol version present in a list
+%%--------------------------------------------------------------------
+lowest_protocol_version([]) ->
+ lowest_protocol_version();
+lowest_protocol_version(Versions) ->
+ [Ver | Vers] = Versions,
+ lowest_list_protocol_version(Ver, Vers).
+
%%--------------------------------------------------------------------
-spec highest_protocol_version([dtls_version()]) -> dtls_version().
%%
@@ -302,6 +314,12 @@ supported_protocol_versions([]) ->
supported_protocol_versions([_|_] = Vsns) ->
Vsns.
+%% highest_protocol_version() ->
+%% highest_protocol_version(supported_protocol_versions()).
+
+lowest_protocol_version() ->
+ lowest_protocol_version(supported_protocol_versions()).
+
supported_connection_protocol_versions([]) ->
?ALL_DATAGRAM_SUPPORTED_VERSIONS.
@@ -421,3 +439,8 @@ mac_hash(Version, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) ->
calc_aad(Type, {MajVer, MinVer}, Epoch, SeqNo) ->
NewSeq = (Epoch bsl 48) + SeqNo,
<<NewSeq:64/integer, ?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer)>>.
+
+lowest_list_protocol_version(Ver, []) ->
+ Ver;
+lowest_list_protocol_version(Ver1, [Ver2 | Rest]) ->
+ lowest_list_protocol_version(lowest_protocol_version(Ver1, Ver2), Rest).