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author | Ingela Anderton Andin <[email protected]> | 2017-11-15 11:07:37 +0100 |
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committer | Ingela Anderton Andin <[email protected]> | 2017-11-16 09:35:25 +0100 |
commit | 6ec865971b3741212573b153fd3ee35d1fd6f796 (patch) | |
tree | 63ff67c134b21fda05ef41639d73b29dea52ba69 /lib/ssl/src/dtls_record.erl | |
parent | ef8032b2c07074e781672821661da1a60396638a (diff) | |
download | otp-6ec865971b3741212573b153fd3ee35d1fd6f796.tar.gz otp-6ec865971b3741212573b153fd3ee35d1fd6f796.tar.bz2 otp-6ec865971b3741212573b153fd3ee35d1fd6f796.zip |
ssl: Align code of TLS/DTLS record handling
Diffstat (limited to 'lib/ssl/src/dtls_record.erl')
-rw-r--r-- | lib/ssl/src/dtls_record.erl | 284 |
1 files changed, 151 insertions, 133 deletions
diff --git a/lib/ssl/src/dtls_record.erl b/lib/ssl/src/dtls_record.erl index a8520717e5..2dcc6efc91 100644 --- a/lib/ssl/src/dtls_record.erl +++ b/lib/ssl/src/dtls_record.erl @@ -32,13 +32,15 @@ %% Handling of incoming data -export([get_dtls_records/2, init_connection_states/2, empty_connection_state/1]). -%% Decoding --export([decode_cipher_text/2]). +-export([save_current_connection_state/2, next_epoch/2, get_connection_state_by_epoch/3, replay_detect/2, + init_connection_state_seq/2, current_connection_state_epoch/2]). %% Encoding -export([encode_handshake/4, encode_alert_record/3, - encode_change_cipher_spec/3, encode_data/3]). --export([encode_plain_text/5]). + encode_change_cipher_spec/3, encode_data/3, encode_plain_text/5]). + +%% Decoding +-export([decode_cipher_text/2]). %% Protocol version handling -export([protocol_version/1, lowest_protocol_version/1, lowest_protocol_version/2, @@ -46,9 +48,6 @@ is_higher/2, supported_protocol_versions/0, is_acceptable_version/2, hello_version/2]). --export([save_current_connection_state/2, next_epoch/2, get_connection_state_by_epoch/3, replay_detect/2]). - --export([init_connection_state_seq/2, current_connection_state_epoch/2]). -export_type([dtls_version/0, dtls_atom_version/0]). @@ -60,7 +59,7 @@ -compile(inline). %%==================================================================== -%% Internal application API +%% Handling of incoming data %%==================================================================== %%-------------------------------------------------------------------- -spec init_connection_states(client | server, one_n_minus_one | zero_n | disabled) -> @@ -86,7 +85,6 @@ init_connection_states(Role, BeastMitigation) -> empty_connection_state(Empty) -> Empty#{epoch => undefined, replay_window => init_replay_window(?REPLAY_WINDOW_SIZE)}. - %%-------------------------------------------------------------------- -spec save_current_connection_state(ssl_record:connection_states(), read | write) -> ssl_record:connection_states(). @@ -137,6 +135,34 @@ set_connection_state_by_epoch(ReadState, Epoch, #{saved_read := #{epoch := Epoch States#{saved_read := ReadState}. %%-------------------------------------------------------------------- +-spec init_connection_state_seq(dtls_version(), ssl_record:connection_states()) -> + ssl_record:connection_state(). +%% +%% Description: Copy the read sequence number to the write sequence number +%% This is only valid for DTLS in the first client_hello +%%-------------------------------------------------------------------- +init_connection_state_seq({254, _}, + #{current_read := #{epoch := 0, sequence_number := Seq}, + current_write := #{epoch := 0} = Write} = ConnnectionStates0) -> + ConnnectionStates0#{current_write => Write#{sequence_number => Seq}}; +init_connection_state_seq(_, ConnnectionStates) -> + ConnnectionStates. + +%%-------------------------------------------------------- +-spec current_connection_state_epoch(ssl_record:connection_states(), read | write) -> + integer(). +%% +%% Description: Returns the epoch the connection_state record +%% that is currently defined as the current connection state. +%%-------------------------------------------------------------------- +current_connection_state_epoch(#{current_read := #{epoch := Epoch}}, + read) -> + Epoch; +current_connection_state_epoch(#{current_write := #{epoch := Epoch}}, + write) -> + Epoch. + +%%-------------------------------------------------------------------- -spec get_dtls_records(binary(), binary()) -> {[binary()], binary()} | #alert{}. %% %% Description: Given old buffer and new data from UDP/SCTP, packs up a records @@ -148,55 +174,10 @@ get_dtls_records(Data, <<>>) -> get_dtls_records(Data, Buffer) -> get_dtls_records_aux(list_to_binary([Buffer, Data]), []). -get_dtls_records_aux(<<?BYTE(?APPLICATION_DATA),?BYTE(MajVer),?BYTE(MinVer), - ?UINT16(Epoch), ?UINT48(SequenceNumber), - ?UINT16(Length), Data:Length/binary, Rest/binary>>, - Acc) -> - get_dtls_records_aux(Rest, [#ssl_tls{type = ?APPLICATION_DATA, - version = {MajVer, MinVer}, - epoch = Epoch, sequence_number = SequenceNumber, - fragment = Data} | Acc]); -get_dtls_records_aux(<<?BYTE(?HANDSHAKE),?BYTE(MajVer),?BYTE(MinVer), - ?UINT16(Epoch), ?UINT48(SequenceNumber), - ?UINT16(Length), - Data:Length/binary, Rest/binary>>, Acc) when MajVer >= 128 -> - get_dtls_records_aux(Rest, [#ssl_tls{type = ?HANDSHAKE, - version = {MajVer, MinVer}, - epoch = Epoch, sequence_number = SequenceNumber, - fragment = Data} | Acc]); -get_dtls_records_aux(<<?BYTE(?ALERT),?BYTE(MajVer),?BYTE(MinVer), - ?UINT16(Epoch), ?UINT48(SequenceNumber), - ?UINT16(Length), Data:Length/binary, - Rest/binary>>, Acc) -> - get_dtls_records_aux(Rest, [#ssl_tls{type = ?ALERT, - version = {MajVer, MinVer}, - epoch = Epoch, sequence_number = SequenceNumber, - fragment = Data} | Acc]); -get_dtls_records_aux(<<?BYTE(?CHANGE_CIPHER_SPEC),?BYTE(MajVer),?BYTE(MinVer), - ?UINT16(Epoch), ?UINT48(SequenceNumber), - ?UINT16(Length), Data:Length/binary, Rest/binary>>, - Acc) -> - get_dtls_records_aux(Rest, [#ssl_tls{type = ?CHANGE_CIPHER_SPEC, - version = {MajVer, MinVer}, - epoch = Epoch, sequence_number = SequenceNumber, - fragment = Data} | Acc]); -get_dtls_records_aux(<<0:1, _CT:7, ?BYTE(_MajVer), ?BYTE(_MinVer), - ?UINT16(Length), _/binary>>, - _Acc) when Length > ?MAX_CIPHER_TEXT_LENGTH -> - ?ALERT_REC(?FATAL, ?RECORD_OVERFLOW); - -get_dtls_records_aux(<<1:1, Length0:15, _/binary>>,_Acc) - when Length0 > ?MAX_CIPHER_TEXT_LENGTH -> - ?ALERT_REC(?FATAL, ?RECORD_OVERFLOW); - -get_dtls_records_aux(Data, Acc) -> - case size(Data) =< ?MAX_CIPHER_TEXT_LENGTH + ?INITIAL_BYTES of - true -> - {lists:reverse(Acc), Data}; - false -> - ?ALERT_REC(?FATAL, ?UNEXPECTED_MESSAGE) - end. +%%==================================================================== +%% Encoding DTLS records +%%==================================================================== %%-------------------------------------------------------------------- -spec encode_handshake(iolist(), dtls_version(), integer(), ssl_record:connection_states()) -> @@ -245,11 +226,19 @@ encode_plain_text(Type, Version, Epoch, Data, ConnectionStates) -> {CipherText, Write} = encode_dtls_cipher_text(Type, Version, CipherFragment, Write1), {CipherText, set_connection_state_by_epoch(Write, Epoch, ConnectionStates, write)}. +%%==================================================================== +%% Decoding +%%==================================================================== decode_cipher_text(#ssl_tls{epoch = Epoch} = CipherText, ConnnectionStates0) -> ReadState = get_connection_state_by_epoch(Epoch, ConnnectionStates0, read), decode_cipher_text(CipherText, ReadState, ConnnectionStates0). + +%%==================================================================== +%% Protocol version handling +%%==================================================================== + %%-------------------------------------------------------------------- -spec protocol_version(dtls_atom_version() | dtls_version()) -> dtls_version() | dtls_atom_version(). @@ -381,35 +370,6 @@ supported_protocol_versions([_|_] = Vsns) -> is_acceptable_version(Version, Versions) -> lists:member(Version, Versions). - -%%-------------------------------------------------------------------- --spec init_connection_state_seq(dtls_version(), ssl_record:connection_states()) -> - ssl_record:connection_state(). -%% -%% Description: Copy the read sequence number to the write sequence number -%% This is only valid for DTLS in the first client_hello -%%-------------------------------------------------------------------- -init_connection_state_seq({254, _}, - #{current_read := #{epoch := 0, sequence_number := Seq}, - current_write := #{epoch := 0} = Write} = ConnnectionStates0) -> - ConnnectionStates0#{current_write => Write#{sequence_number => Seq}}; -init_connection_state_seq(_, ConnnectionStates) -> - ConnnectionStates. - -%%-------------------------------------------------------- --spec current_connection_state_epoch(ssl_record:connection_states(), read | write) -> - integer(). -%% -%% Description: Returns the epoch the connection_state record -%% that is currently defined as the current connection state. -%%-------------------------------------------------------------------- -current_connection_state_epoch(#{current_read := #{epoch := Epoch}}, - read) -> - Epoch; -current_connection_state_epoch(#{current_write := #{epoch := Epoch}}, - write) -> - Epoch. - -spec hello_version(dtls_version(), [dtls_version()]) -> dtls_version(). hello_version(Version, Versions) -> case dtls_v1:corresponding_tls_version(Version) of @@ -438,15 +398,93 @@ initial_connection_state(ConnectionEnd, BeastMitigation) -> server_verify_data => undefined }. -lowest_list_protocol_version(Ver, []) -> - Ver; -lowest_list_protocol_version(Ver1, [Ver2 | Rest]) -> - lowest_list_protocol_version(lowest_protocol_version(Ver1, Ver2), Rest). +get_dtls_records_aux(<<?BYTE(?APPLICATION_DATA),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Epoch), ?UINT48(SequenceNumber), + ?UINT16(Length), Data:Length/binary, Rest/binary>>, + Acc) -> + get_dtls_records_aux(Rest, [#ssl_tls{type = ?APPLICATION_DATA, + version = {MajVer, MinVer}, + epoch = Epoch, sequence_number = SequenceNumber, + fragment = Data} | Acc]); +get_dtls_records_aux(<<?BYTE(?HANDSHAKE),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Epoch), ?UINT48(SequenceNumber), + ?UINT16(Length), + Data:Length/binary, Rest/binary>>, Acc) when MajVer >= 128 -> + get_dtls_records_aux(Rest, [#ssl_tls{type = ?HANDSHAKE, + version = {MajVer, MinVer}, + epoch = Epoch, sequence_number = SequenceNumber, + fragment = Data} | Acc]); +get_dtls_records_aux(<<?BYTE(?ALERT),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Epoch), ?UINT48(SequenceNumber), + ?UINT16(Length), Data:Length/binary, + Rest/binary>>, Acc) -> + get_dtls_records_aux(Rest, [#ssl_tls{type = ?ALERT, + version = {MajVer, MinVer}, + epoch = Epoch, sequence_number = SequenceNumber, + fragment = Data} | Acc]); +get_dtls_records_aux(<<?BYTE(?CHANGE_CIPHER_SPEC),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Epoch), ?UINT48(SequenceNumber), + ?UINT16(Length), Data:Length/binary, Rest/binary>>, + Acc) -> + get_dtls_records_aux(Rest, [#ssl_tls{type = ?CHANGE_CIPHER_SPEC, + version = {MajVer, MinVer}, + epoch = Epoch, sequence_number = SequenceNumber, + fragment = Data} | Acc]); -highest_list_protocol_version(Ver, []) -> - Ver; -highest_list_protocol_version(Ver1, [Ver2 | Rest]) -> - highest_list_protocol_version(highest_protocol_version(Ver1, Ver2), Rest). +get_dtls_records_aux(<<0:1, _CT:7, ?BYTE(_MajVer), ?BYTE(_MinVer), + ?UINT16(Length), _/binary>>, + _Acc) when Length > ?MAX_CIPHER_TEXT_LENGTH -> + ?ALERT_REC(?FATAL, ?RECORD_OVERFLOW); + +get_dtls_records_aux(<<1:1, Length0:15, _/binary>>,_Acc) + when Length0 > ?MAX_CIPHER_TEXT_LENGTH -> + ?ALERT_REC(?FATAL, ?RECORD_OVERFLOW); + +get_dtls_records_aux(Data, Acc) -> + case size(Data) =< ?MAX_CIPHER_TEXT_LENGTH + ?INITIAL_BYTES of + true -> + {lists:reverse(Acc), Data}; + false -> + ?ALERT_REC(?FATAL, ?UNEXPECTED_MESSAGE) + end. +%%-------------------------------------------------------------------- + +init_replay_window(Size) -> + #{size => Size, + top => Size, + bottom => 0, + mask => 0 bsl 64 + }. + +replay_detect(#ssl_tls{sequence_number = SequenceNumber}, #{replay_window := Window}) -> + is_replay(SequenceNumber, Window). + + +is_replay(SequenceNumber, #{bottom := Bottom}) when SequenceNumber < Bottom -> + true; +is_replay(SequenceNumber, #{size := Size, + top := Top, + bottom := Bottom, + mask := Mask}) when (SequenceNumber >= Bottom) andalso (SequenceNumber =< Top) -> + Index = (SequenceNumber rem Size), + (Index band Mask) == 1; + +is_replay(_, _) -> + false. + +update_replay_window(SequenceNumber, #{replay_window := #{size := Size, + top := Top, + bottom := Bottom, + mask := Mask0} = Window0} = ConnectionStates) -> + NoNewBits = SequenceNumber - Top, + Index = SequenceNumber rem Size, + Mask = (Mask0 bsl NoNewBits) bor Index, + Window = Window0#{top => SequenceNumber, + bottom => Bottom + NoNewBits, + mask => Mask}, + ConnectionStates#{replay_window := Window}. + +%%-------------------------------------------------------------------- encode_dtls_cipher_text(Type, {MajVer, MinVer}, Fragment, #{epoch := Epoch, sequence_number := Seq} = WriteState) -> @@ -490,6 +528,7 @@ encode_plain_text(Type, Version, Fragment, #{compression_state := CompS0, ssl_cipher:cipher(BulkCipherAlgo, CipherS0, MAC, Fragment, TLSVersion), {CipherFragment, WriteState0#{cipher_state => CipherS1}}. +%%-------------------------------------------------------------------- decode_cipher_text(#ssl_tls{type = Type, version = Version, epoch = Epoch, sequence_number = Seq, @@ -541,6 +580,7 @@ decode_cipher_text(#ssl_tls{type = Type, version = Version, false -> ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) end. +%%-------------------------------------------------------------------- calc_mac_hash(Type, Version, #{mac_secret := MacSecret, security_parameters := #security_parameters{mac_algorithm = MacAlg}}, @@ -549,16 +589,6 @@ calc_mac_hash(Type, Version, #{mac_secret := MacSecret, mac_hash(Version, MacAlg, MacSecret, Epoch, SeqNo, Type, Length, Fragment). -highest_protocol_version() -> - highest_protocol_version(supported_protocol_versions()). - -lowest_protocol_version() -> - lowest_protocol_version(supported_protocol_versions()). - -sufficient_dtlsv1_2_crypto_support() -> - CryptoSupport = crypto:supports(), - proplists:get_bool(sha256, proplists:get_value(hashs, CryptoSupport)). - mac_hash({Major, Minor}, MacAlg, MacSecret, Epoch, SeqNo, Type, Length, Fragment) -> Value = [<<?UINT16(Epoch), ?UINT48(SeqNo), ?BYTE(Type), ?BYTE(Major), ?BYTE(Minor), ?UINT16(Length)>>, @@ -568,37 +598,25 @@ mac_hash({Major, Minor}, MacAlg, MacSecret, Epoch, SeqNo, Type, Length, Fragment calc_aad(Type, {MajVer, MinVer}, Epoch, SeqNo) -> <<?UINT16(Epoch), ?UINT48(SeqNo), ?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer)>>. -init_replay_window(Size) -> - #{size => Size, - top => Size, - bottom => 0, - mask => 0 bsl 64 - }. +%%-------------------------------------------------------------------- -replay_detect(#ssl_tls{sequence_number = SequenceNumber}, #{replay_window := Window}) -> - is_replay(SequenceNumber, Window). +lowest_list_protocol_version(Ver, []) -> + Ver; +lowest_list_protocol_version(Ver1, [Ver2 | Rest]) -> + lowest_list_protocol_version(lowest_protocol_version(Ver1, Ver2), Rest). +highest_list_protocol_version(Ver, []) -> + Ver; +highest_list_protocol_version(Ver1, [Ver2 | Rest]) -> + highest_list_protocol_version(highest_protocol_version(Ver1, Ver2), Rest). -is_replay(SequenceNumber, #{bottom := Bottom}) when SequenceNumber < Bottom -> - true; -is_replay(SequenceNumber, #{size := Size, - top := Top, - bottom := Bottom, - mask := Mask}) when (SequenceNumber >= Bottom) andalso (SequenceNumber =< Top) -> - Index = (SequenceNumber rem Size), - (Index band Mask) == 1; +highest_protocol_version() -> + highest_protocol_version(supported_protocol_versions()). -is_replay(_, _) -> - false. +lowest_protocol_version() -> + lowest_protocol_version(supported_protocol_versions()). + +sufficient_dtlsv1_2_crypto_support() -> + CryptoSupport = crypto:supports(), + proplists:get_bool(sha256, proplists:get_value(hashs, CryptoSupport)). -update_replay_window(SequenceNumber, #{replay_window := #{size := Size, - top := Top, - bottom := Bottom, - mask := Mask0} = Window0} = ConnectionStates) -> - NoNewBits = SequenceNumber - Top, - Index = SequenceNumber rem Size, - Mask = (Mask0 bsl NoNewBits) bor Index, - Window = Window0#{top => SequenceNumber, - bottom => Bottom + NoNewBits, - mask => Mask}, - ConnectionStates#{replay_window := Window}. |