diff options
Diffstat (limited to 'lib/ssl/src/dtls_record.erl')
| -rw-r--r-- | lib/ssl/src/dtls_record.erl | 55 |
1 files changed, 49 insertions, 6 deletions
diff --git a/lib/ssl/src/dtls_record.erl b/lib/ssl/src/dtls_record.erl index 6a418c6fb1..8a7f8c1d0a 100644 --- a/lib/ssl/src/dtls_record.erl +++ b/lib/ssl/src/dtls_record.erl @@ -46,7 +46,7 @@ is_higher/2, supported_protocol_versions/0, is_acceptable_version/2, hello_version/2]). --export([save_current_connection_state/2, next_epoch/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]). @@ -55,6 +55,8 @@ -type dtls_version() :: ssl_record:ssl_version(). -type dtls_atom_version() :: dtlsv1 | 'dtlsv1.2'. +-define(REPLAY_WINDOW_SIZE, 64). + -compile(inline). %%==================================================================== @@ -73,7 +75,7 @@ init_connection_states(Role, BeastMitigation) -> Initial = initial_connection_state(ConnectionEnd, BeastMitigation), Current = Initial#{epoch := 0}, InitialPending = ssl_record:empty_connection_state(ConnectionEnd, BeastMitigation), - Pending = InitialPending#{epoch => undefined}, + Pending = InitialPending#{epoch => undefined, replay_window => init_replay_window(?REPLAY_WINDOW_SIZE)}, #{saved_read => Current, current_read => Current, pending_read => Pending, @@ -96,11 +98,13 @@ save_current_connection_state(#{current_write := Current} = States, write) -> next_epoch(#{pending_read := Pending, current_read := #{epoch := Epoch}} = States, read) -> - States#{pending_read := Pending#{epoch := Epoch + 1}}; + States#{pending_read := Pending#{epoch := Epoch + 1, + replay_window := init_replay_window(?REPLAY_WINDOW_SIZE)}}; next_epoch(#{pending_write := Pending, current_write := #{epoch := Epoch}} = States, write) -> - States#{pending_write := Pending#{epoch := Epoch + 1}}. + States#{pending_write := Pending#{epoch := Epoch + 1, + replay_window := init_replay_window(?REPLAY_WINDOW_SIZE)}}. get_connection_state_by_epoch(Epoch, #{current_write := #{epoch := Epoch} = Current}, write) -> @@ -411,6 +415,7 @@ hello_version(Version, Versions) -> lowest_protocol_version(Versions) end. + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- @@ -419,6 +424,7 @@ initial_connection_state(ConnectionEnd, BeastMitigation) -> ssl_record:initial_security_params(ConnectionEnd), epoch => undefined, sequence_number => 0, + replay_window => init_replay_window(?REPLAY_WINDOW_SIZE), beast_mitigation => BeastMitigation, compression_state => undefined, cipher_state => undefined, @@ -499,8 +505,9 @@ decode_cipher_text(#ssl_tls{type = Type, version = Version, {PlainFragment, CipherState} -> {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, PlainFragment, CompressionS0), - ReadState = ReadState0#{compression_state => CompressionS1, + ReadState0 = ReadState0#{compression_state => CompressionS1, cipher_state => CipherState}, + ReadState = update_replay_window(Seq, ReadState0), ConnnectionStates = set_connection_state_by_epoch(ReadState, Epoch, ConnnectionStates0, read), {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; #alert{} = Alert -> @@ -523,7 +530,8 @@ decode_cipher_text(#ssl_tls{type = Type, version = Version, {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, PlainFragment, CompressionS0), - ReadState = ReadState1#{compression_state => CompressionS1}, + ReadState2 = ReadState1#{compression_state => CompressionS1}, + ReadState = update_replay_window(Seq, ReadState2), ConnnectionStates = set_connection_state_by_epoch(ReadState, Epoch, ConnnectionStates0, read), {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; false -> @@ -555,3 +563,38 @@ 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). + + +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}. |