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authorIngela Anderton Andin <[email protected]>2016-09-20 20:58:34 +0200
committerIngela Anderton Andin <[email protected]>2016-12-05 10:59:51 +0100
commit1e6942e97339ff39a0436834c260bf50c3d3a481 (patch)
treea7b277fe925fc74dd186faf64f3d24ac066de5bd /lib/ssl/src/dtls_handshake.erl
parent39fef8eec26c2903ef11ba8829e1f625906b3e11 (diff)
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ssl: Implement DTLS state machine
Beta DTLS, not production ready. Only very basically tested, and not everything in the SPEC is implemented and some things are hard coded that should not be, so this implementation can not be consider secure. Refactor "TLS connection state" and socket handling, to facilitate DTLS implementation. Create dtls "listner" (multiplexor) process that spawns DTLS connection process handlers. Handle DTLS fragmentation. Framework for handling retransmissions. Replay Detection is not implemented yet. Alerts currently always handled as in TLS.
Diffstat (limited to 'lib/ssl/src/dtls_handshake.erl')
-rw-r--r--lib/ssl/src/dtls_handshake.erl555
1 files changed, 273 insertions, 282 deletions
diff --git a/lib/ssl/src/dtls_handshake.erl b/lib/ssl/src/dtls_handshake.erl
index c6535d5928..af3708ddb7 100644
--- a/lib/ssl/src/dtls_handshake.erl
+++ b/lib/ssl/src/dtls_handshake.erl
@@ -18,15 +18,15 @@
%% %CopyrightEnd%
-module(dtls_handshake).
+-include("dtls_connection.hrl").
-include("dtls_handshake.hrl").
-include("dtls_record.hrl").
-include("ssl_internal.hrl").
-include("ssl_alert.hrl").
--export([client_hello/8, client_hello/9, hello/4,
- hello_verify_request/1, get_dtls_handshake/2,
- dtls_handshake_new_flight/1, dtls_handshake_new_epoch/1,
- encode_handshake/3]).
+-export([client_hello/8, client_hello/9, cookie/4, hello/4,
+ hello_verify_request/2, get_dtls_handshake/3, fragment_handshake/2,
+ handshake_bin/2, encode_handshake/3]).
-type dtls_handshake() :: #client_hello{} | #hello_verify_request{} |
ssl_handshake:ssl_handshake().
@@ -62,9 +62,10 @@ client_hello(Host, Port, Cookie, ConnectionStates,
Version = dtls_record:highest_protocol_version(Versions),
Pending = ssl_record:pending_connection_state(ConnectionStates, read),
SecParams = maps:get(security_parameters, Pending),
- CipherSuites = ssl_handshake:available_suites(UserSuites, Version),
+ TLSVersion = dtls_v1:corresponding_tls_version(Version),
+ CipherSuites = ssl_handshake:available_suites(UserSuites, TLSVersion),
- Extensions = ssl_handshake:client_hello_extensions(Host, dtls_v1:corresponding_tls_version(Version), CipherSuites,
+ Extensions = ssl_handshake:client_hello_extensions(Host, TLSVersion, CipherSuites,
SslOpts, ConnectionStates, Renegotiation),
Id = ssl_session:client_id({Host, Port, SslOpts}, Cache, CacheCb, OwnCert),
@@ -96,72 +97,51 @@ hello(#client_hello{client_version = ClientVersion} = Hello,
#ssl_options{versions = Versions} = SslOpts,
Info, Renegotiation) ->
Version = ssl_handshake:select_version(dtls_record, ClientVersion, Versions),
- %%
- %% TODO: handle Cipher Fallback
- %%
handle_client_hello(Version, Hello, SslOpts, Info, Renegotiation).
--spec hello_verify_request(binary()) -> #hello_verify_request{}.
+cookie(Key, Address, Port, #client_hello{client_version = {Major, Minor},
+ random = Random,
+ session_id = SessionId,
+ cipher_suites = CipherSuites,
+ compression_methods = CompressionMethods}) ->
+ CookieData = [address_to_bin(Address, Port),
+ <<?BYTE(Major), ?BYTE(Minor)>>,
+ Random, SessionId, CipherSuites, CompressionMethods],
+ crypto:hmac(sha, Key, CookieData).
+
+-spec hello_verify_request(binary(), dtls_record:dtls_version()) -> #hello_verify_request{}.
%%
%% Description: Creates a hello verify request message sent by server to
%% verify client
%%--------------------------------------------------------------------
-hello_verify_request(Cookie) ->
- %% TODO: DTLS Versions?????
- #hello_verify_request{protocol_version = {254, 255}, cookie = Cookie}.
+hello_verify_request(Cookie, Version) ->
+ #hello_verify_request{protocol_version = Version, cookie = Cookie}.
%%--------------------------------------------------------------------
-%% %%--------------------------------------------------------------------
-encode_handshake(Handshake, Version, MsgSeq) ->
+encode_handshake(Handshake, Version, Seq) ->
{MsgType, Bin} = enc_handshake(Handshake, Version),
Len = byte_size(Bin),
- Enc = [MsgType, ?uint24(Len), ?uint16(MsgSeq), ?uint24(0), ?uint24(Len), Bin],
- Frag = {MsgType, MsgSeq, Bin},
- {Enc, Frag}.
+ [MsgType, ?uint24(Len), ?uint16(Seq), ?uint24(0), ?uint24(Len), Bin].
-%%--------------------------------------------------------------------
--spec get_dtls_handshake(#ssl_tls{}, #dtls_hs_state{} | undefined) ->
- {[dtls_handshake()], #dtls_hs_state{}} | {retransmit, #dtls_hs_state{}}.
-%%
-%% Description: Given a DTLS state and new data from ssl_record, collects
-%% and returns it as a list of handshake messages, also returns a new
-%% DTLS state
-%%--------------------------------------------------------------------
-get_dtls_handshake(Records, undefined) ->
- HsState = #dtls_hs_state{highest_record_seq = 0,
- starting_read_seq = 0,
- fragments = gb_trees:empty(),
- completed = []},
- get_dtls_handshake(Records, HsState);
-get_dtls_handshake(Records, HsState0) when is_list(Records) ->
- HsState1 = lists:foldr(fun get_dtls_handshake_aux/2, HsState0, Records),
- get_dtls_handshake_completed(HsState1);
-get_dtls_handshake(Record, HsState0) when is_record(Record, ssl_tls) ->
- HsState1 = get_dtls_handshake_aux(Record, HsState0),
- get_dtls_handshake_completed(HsState1).
+fragment_handshake(Bin, _) when is_binary(Bin)->
+ %% This is the change_cipher_spec not a "real handshake" but part of the flight
+ Bin;
+fragment_handshake([MsgType, Len, Seq, _, Len, Bin], Size) ->
+ Bins = bin_fragments(Bin, Size),
+ handshake_fragments(MsgType, Seq, Len, Bins, []).
+handshake_bin([Type, Length, Data], Seq) ->
+ handshake_bin(Type, Length, Seq, Data).
+
%%--------------------------------------------------------------------
--spec dtls_handshake_new_epoch(#dtls_hs_state{}) -> #dtls_hs_state{}.
+-spec get_dtls_handshake(dtls_record:dtls_version(), binary(), #protocol_buffers{}) ->
+ {[{dtls_handshake(), binary()}], #protocol_buffers{}} | {more_data, #protocol_buffers{}}.
%%
-%% Description: Reset the DTLS decoder state for a new Epoch
+%% Description: ...
%%--------------------------------------------------------------------
-%% dtls_handshake_new_epoch(<<>>) ->
-%% dtls_hs_state_init();
-dtls_handshake_new_epoch(HsState) ->
- HsState#dtls_hs_state{highest_record_seq = 0,
- starting_read_seq = HsState#dtls_hs_state.current_read_seq,
- fragments = gb_trees:empty(), completed = []}.
-
-%--------------------------------------------------------------------
--spec dtls_handshake_new_flight(integer() | undefined) -> #dtls_hs_state{}.
-%
-% Description: Init the DTLS decoder state for a new Flight
-dtls_handshake_new_flight(ExpectedReadReq) ->
- #dtls_hs_state{current_read_seq = ExpectedReadReq,
- highest_record_seq = 0,
- starting_read_seq = 0,
- fragments = gb_trees:empty(), completed = []}.
+get_dtls_handshake(Version, Fragment, ProtocolBuffers) ->
+ handle_fragments(Version, Fragment, ProtocolBuffers, []).
%%--------------------------------------------------------------------
%%% Internal functions
@@ -170,27 +150,29 @@ handle_client_hello(Version, #client_hello{session_id = SugesstedId,
cipher_suites = CipherSuites,
compression_methods = Compressions,
random = Random,
- extensions = #hello_extensions{elliptic_curves = Curves,
- signature_algs = ClientHashSigns} = HelloExt},
+ extensions =
+ #hello_extensions{elliptic_curves = Curves,
+ signature_algs = ClientHashSigns} = HelloExt},
#ssl_options{versions = Versions,
signature_algs = SupportedHashSigns} = SslOpts,
{Port, Session0, Cache, CacheCb, ConnectionStates0, Cert, _}, Renegotiation) ->
case dtls_record:is_acceptable_version(Version, Versions) of
true ->
+ TLSVersion = dtls_v1:corresponding_tls_version(Version),
AvailableHashSigns = ssl_handshake:available_signature_algs(
- ClientHashSigns, SupportedHashSigns, Cert,
- dtls_v1:corresponding_tls_version(Version)),
- ECCCurve = ssl_handshake:select_curve(Curves, ssl_handshake:supported_ecc(Version)),
+ ClientHashSigns, SupportedHashSigns, Cert,TLSVersion),
+ ECCCurve = ssl_handshake:select_curve(Curves, ssl_handshake:supported_ecc(TLSVersion)),
{Type, #session{cipher_suite = CipherSuite} = Session1}
= ssl_handshake:select_session(SugesstedId, CipherSuites, AvailableHashSigns, Compressions,
- Port, Session0#session{ecc = ECCCurve}, Version,
+ Port, Session0#session{ecc = ECCCurve}, TLSVersion,
SslOpts, Cache, CacheCb, Cert),
case CipherSuite of
no_suite ->
?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY);
_ ->
{KeyExAlg,_,_,_} = ssl_cipher:suite_definition(CipherSuite),
- case ssl_handshake:select_hashsign(ClientHashSigns, Cert, KeyExAlg, SupportedHashSigns, Version) of
+ case ssl_handshake:select_hashsign(ClientHashSigns, Cert, KeyExAlg,
+ SupportedHashSigns, TLSVersion) of
#alert{} = Alert ->
Alert;
HashSign ->
@@ -228,214 +210,15 @@ handle_server_hello_extensions(Version, SessionId, Random, CipherSuite,
{Version, SessionId, ConnectionStates, ProtoExt, Protocol}
end.
-get_dtls_handshake_completed(HsState = #dtls_hs_state{completed = Completed}) ->
- {lists:reverse(Completed), HsState#dtls_hs_state{completed = []}}.
-
-get_dtls_handshake_aux(#ssl_tls{version = Version,
- sequence_number = SeqNo,
- fragment = Data}, HsState) ->
- get_dtls_handshake_aux(Version, SeqNo, Data, HsState).
-
-get_dtls_handshake_aux(Version, SeqNo,
- <<?BYTE(Type), ?UINT24(Length),
- ?UINT16(MessageSeq),
- ?UINT24(FragmentOffset), ?UINT24(FragmentLength),
- Body:FragmentLength/binary, Rest/binary>>,
- HsState0) ->
- case reassemble_dtls_fragment(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body, HsState0) of
- {HsState1, HighestSeqNo, MsgBody} ->
- HsState2 = dec_dtls_fragment(Version, HighestSeqNo, Type, Length, MessageSeq, MsgBody, HsState1),
- HsState3 = process_dtls_fragments(Version, HsState2),
- get_dtls_handshake_aux(Version, SeqNo, Rest, HsState3);
-
- HsState2 ->
- HsState3 = process_dtls_fragments(Version, HsState2),
- get_dtls_handshake_aux(Version, SeqNo, Rest, HsState3)
- end;
-
-get_dtls_handshake_aux(_Version, _SeqNo, <<>>, HsState) ->
- HsState.
-
-dec_dtls_fragment(Version, SeqNo, Type, Length, MessageSeq, MsgBody,
- HsState = #dtls_hs_state{highest_record_seq = HighestSeqNo, completed = Acc}) ->
- Raw = <<?BYTE(Type), ?UINT24(Length), ?UINT16(MessageSeq), ?UINT24(0), ?UINT24(Length), MsgBody/binary>>,
- H = decode_handshake(Version, Type, MsgBody),
- HsState#dtls_hs_state{completed = [{H,Raw}|Acc], highest_record_seq = erlang:max(HighestSeqNo, SeqNo)}.
-
-process_dtls_fragments(Version,
- HsState0 = #dtls_hs_state{current_read_seq = CurrentReadSeq,
- fragments = Fragments0}) ->
- case gb_trees:is_empty(Fragments0) of
- true ->
- HsState0;
- _ ->
- case gb_trees:smallest(Fragments0) of
- {CurrentReadSeq, {SeqNo, Type, Length, CurrentReadSeq, {Length, [{0, Length}], MsgBody}}} ->
- HsState1 = dtls_hs_state_process_seq(HsState0),
- HsState2 = dec_dtls_fragment(Version, SeqNo, Type, Length, CurrentReadSeq, MsgBody, HsState1),
- process_dtls_fragments(Version, HsState2);
- _ ->
- HsState0
- end
- end.
-
-dtls_hs_state_process_seq(HsState0 = #dtls_hs_state{current_read_seq = CurrentReadSeq,
- fragments = Fragments0}) ->
- Fragments1 = gb_trees:delete_any(CurrentReadSeq, Fragments0),
- HsState0#dtls_hs_state{current_read_seq = CurrentReadSeq + 1,
- fragments = Fragments1}.
-
-dtls_hs_state_add_fragment(MessageSeq, Fragment, HsState0 = #dtls_hs_state{fragments = Fragments0}) ->
- Fragments1 = gb_trees:enter(MessageSeq, Fragment, Fragments0),
- HsState0#dtls_hs_state{fragments = Fragments1}.
-
-reassemble_dtls_fragment(SeqNo, Type, Length, MessageSeq, 0, Length,
- Body, HsState0 = #dtls_hs_state{current_read_seq = undefined})
- when Type == ?CLIENT_HELLO;
- Type == ?SERVER_HELLO;
- Type == ?HELLO_VERIFY_REQUEST ->
- %% First message, should be client hello
- %% return the current message and set the next expected Sequence
- %%
- %% Note: this could (should?) be restricted further, ClientHello and
- %% HelloVerifyRequest have to have message_seq = 0, ServerHello
- %% can have a message_seq of 0 or 1
- %%
- {HsState0#dtls_hs_state{current_read_seq = MessageSeq + 1}, SeqNo, Body};
-
-reassemble_dtls_fragment(_SeqNo, _Type, Length, _MessageSeq, _, Length,
- _Body, HsState = #dtls_hs_state{current_read_seq = undefined}) ->
- %% not what we expected, drop it
- HsState;
-
-reassemble_dtls_fragment(SeqNo, _Type, Length, MessageSeq, 0, Length,
- Body, HsState0 =
- #dtls_hs_state{starting_read_seq = StartingReadSeq})
- when MessageSeq < StartingReadSeq ->
- %% this has to be the start of a new flight, let it through
- %%
- %% Note: this could (should?) be restricted further, the first message of a
- %% new flight has to have message_seq = 0
- %%
- HsState = dtls_hs_state_process_seq(HsState0),
- {HsState, SeqNo, Body};
-
-reassemble_dtls_fragment(_SeqNo, _Type, Length, MessageSeq, 0, Length,
- _Body, HsState = #dtls_hs_state{current_read_seq = CurrentReadSeq})
- when MessageSeq < CurrentReadSeq ->
- HsState;
-
-reassemble_dtls_fragment(SeqNo, _Type, Length, MessageSeq, 0, Length,
- Body, HsState0 = #dtls_hs_state{current_read_seq = MessageSeq}) ->
- %% Message fully contained and it's the current seq
- HsState1 = dtls_hs_state_process_seq(HsState0),
- {HsState1, SeqNo, Body};
-
-reassemble_dtls_fragment(SeqNo, Type, Length, MessageSeq, 0, Length,
- Body, HsState) ->
- %% Message fully contained and it's the NOT the current seq -> buffer
- Fragment = {SeqNo, Type, Length, MessageSeq,
- dtls_fragment_init(Length, 0, Length, Body)},
- dtls_hs_state_add_fragment(MessageSeq, Fragment, HsState);
-
-reassemble_dtls_fragment(_SeqNo, _Type, Length, MessageSeq, FragmentOffset, FragmentLength,
- _Body,
- HsState = #dtls_hs_state{current_read_seq = CurrentReadSeq})
- when FragmentOffset + FragmentLength == Length andalso MessageSeq == (CurrentReadSeq - 1) ->
- {retransmit, HsState};
-
-reassemble_dtls_fragment(_SeqNo, _Type, _Length, MessageSeq, _FragmentOffset, _FragmentLength,
- _Body,
- HsState = #dtls_hs_state{current_read_seq = CurrentReadSeq})
- when MessageSeq < CurrentReadSeq ->
- HsState;
-
-reassemble_dtls_fragment(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body,
- HsState = #dtls_hs_state{fragments = Fragments0}) ->
- case gb_trees:lookup(MessageSeq, Fragments0) of
- {value, Fragment} ->
- dtls_fragment_reassemble(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body, Fragment, HsState);
- none ->
- dtls_fragment_start(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body, HsState)
- end.
-dtls_fragment_start(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body, HsState = #dtls_hs_state{fragments = Fragments0}) ->
- Fragment = {SeqNo, Type, Length, MessageSeq,
- dtls_fragment_init(Length, FragmentOffset, FragmentLength, Body)},
- Fragments1 = gb_trees:insert(MessageSeq, Fragment, Fragments0),
- HsState#dtls_hs_state{fragments = Fragments1}.
-
-dtls_fragment_reassemble(SeqNo, Type, Length, MessageSeq,
- FragmentOffset, FragmentLength,
- Body,
- {LastSeqNo, Type, Length, MessageSeq, FragBuffer0},
- HsState = #dtls_hs_state{fragments = Fragments0}) ->
- FragBuffer1 = dtls_fragment_add(FragBuffer0, FragmentOffset, FragmentLength, Body),
- Fragment = {erlang:max(SeqNo, LastSeqNo), Type, Length, MessageSeq, FragBuffer1},
- Fragments1 = gb_trees:enter(MessageSeq, Fragment, Fragments0),
- HsState#dtls_hs_state{fragments = Fragments1};
-
-%% Type, Length or Seq mismatch, drop everything...
-%% Note: the RFC is not clear on how to handle this...
-dtls_fragment_reassemble(_SeqNo, _Type, _Length, MessageSeq,
- _FragmentOffset, _FragmentLength, _Body, _Fragment,
- HsState = #dtls_hs_state{fragments = Fragments0}) ->
- Fragments1 = gb_trees:delete_any(MessageSeq, Fragments0),
- HsState#dtls_hs_state{fragments = Fragments1}.
-
-dtls_fragment_add({Length, FragmentList0, Bin0}, FragmentOffset, FragmentLength, Body) ->
- Bin1 = dtls_fragment_bin_add(FragmentOffset, FragmentLength, Body, Bin0),
- FragmentList1 = add_fragment(FragmentList0, {FragmentOffset, FragmentLength}),
- {Length, FragmentList1, Bin1}.
-
-dtls_fragment_init(Length, 0, Length, Body) ->
- {Length, [{0, Length}], Body};
-dtls_fragment_init(Length, FragmentOffset, FragmentLength, Body) ->
- Bin = dtls_fragment_bin_add(FragmentOffset, FragmentLength, Body, <<0:(Length*8)>>),
- {Length, [{FragmentOffset, FragmentOffset + FragmentLength}], Bin}.
-
-dtls_fragment_bin_add(FragmentOffset, FragmentLength, Add, Buffer) ->
- <<First:FragmentOffset/bytes, _:FragmentLength/bytes, Rest/binary>> = Buffer,
- <<First/binary, Add/binary, Rest/binary>>.
-
-merge_fragment_list([], Fragment, Acc) ->
- lists:reverse([Fragment|Acc]);
-
-merge_fragment_list([H = {_, HEnd}|Rest], Frag = {FStart, _}, Acc)
- when FStart > HEnd ->
- merge_fragment_list(Rest, Frag, [H|Acc]);
-
-merge_fragment_list(Rest = [{HStart, _HEnd}|_], Frag = {_FStart, FEnd}, Acc)
- when FEnd < HStart ->
- lists:reverse(Acc) ++ [Frag|Rest];
-
-merge_fragment_list([{HStart, HEnd}|Rest], _Frag = {FStart, FEnd}, Acc)
- when
- FStart =< HEnd orelse FEnd >= HStart ->
- Start = erlang:min(HStart, FStart),
- End = erlang:max(HEnd, FEnd),
- NewFrag = {Start, End},
- merge_fragment_list(Rest, NewFrag, Acc).
-
-add_fragment(List, {FragmentOffset, FragmentLength}) ->
- merge_fragment_list(List, {FragmentOffset, FragmentOffset + FragmentLength}, []).
+%%%%%%% Encodeing %%%%%%%%%%%%%
enc_handshake(#hello_verify_request{protocol_version = {Major, Minor},
cookie = Cookie}, _Version) ->
- CookieLength = byte_size(Cookie),
+ CookieLength = byte_size(Cookie),
{?HELLO_VERIFY_REQUEST, <<?BYTE(Major), ?BYTE(Minor),
?BYTE(CookieLength),
- Cookie/binary>>};
+ Cookie:CookieLength/binary>>};
enc_handshake(#hello_request{}, _Version) ->
{?HELLO_REQUEST, <<>>};
@@ -459,38 +242,246 @@ enc_handshake(#client_hello{client_version = {Major, Minor},
?BYTE(CookieLength), Cookie/binary,
?UINT16(CsLength), BinCipherSuites/binary,
?BYTE(CmLength), BinCompMethods/binary, ExtensionsBin/binary>>};
+
+enc_handshake(#server_hello{} = HandshakeMsg, Version) ->
+ {Type, <<?BYTE(Major), ?BYTE(Minor), Rest/binary>>} =
+ ssl_handshake:encode_handshake(HandshakeMsg, Version),
+ {DTLSMajor, DTLSMinor} = dtls_v1:corresponding_dtls_version({Major, Minor}),
+ {Type, <<?BYTE(DTLSMajor), ?BYTE(DTLSMinor), Rest/binary>>};
+
enc_handshake(HandshakeMsg, Version) ->
ssl_handshake:encode_handshake(HandshakeMsg, Version).
-decode_handshake(_Version, ?CLIENT_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
+bin_fragments(Bin, Size) ->
+ bin_fragments(Bin, size(Bin), Size, 0, []).
+
+bin_fragments(Bin, BinSize, FragSize, Offset, Fragments) ->
+ case (BinSize - Offset - FragSize) > 0 of
+ true ->
+ Frag = binary:part(Bin, {Offset, FragSize}),
+ bin_fragments(Bin, BinSize, FragSize, Offset + FragSize, [{Frag, Offset} | Fragments]);
+ false ->
+ Frag = binary:part(Bin, {Offset, BinSize-Offset}),
+ lists:reverse([{Frag, Offset} | Fragments])
+ end.
+
+handshake_fragments(_, _, _, [], Acc) ->
+ lists:reverse(Acc);
+handshake_fragments(MsgType, Seq, Len, [{Bin, Offset} | Bins], Acc) ->
+ FragLen = size(Bin),
+ handshake_fragments(MsgType, Seq, Len, Bins,
+ [<<?BYTE(MsgType), Len/binary, Seq/binary, ?UINT24(Offset),
+ ?UINT24(FragLen), Bin/binary>> | Acc]).
+
+address_to_bin({A,B,C,D}, Port) ->
+ <<0:80,16#ffff:16,A,B,C,D,Port:16>>;
+address_to_bin({A,B,C,D,E,F,G,H}, Port) ->
+ <<A:16,B:16,C:16,D:16,E:16,F:16,G:16,H:16,Port:16>>.
+
+%%%%%%% Decodeing %%%%%%%%%%%%%
+
+handle_fragments(Version, FragmentData, Buffers0, Acc) ->
+ Fragments = decode_handshake_fragments(FragmentData),
+ do_handle_fragments(Version, Fragments, Buffers0, Acc).
+
+do_handle_fragments(_, [], Buffers, Acc) ->
+ {lists:reverse(Acc), Buffers};
+do_handle_fragments(Version, [Fragment | Fragments], Buffers0, Acc) ->
+ case reassemble(Version, Fragment, Buffers0) of
+ {more_data, _} = More when Acc == []->
+ More;
+ {more_data, Buffers} when Fragments == [] ->
+ {lists:reverse(Acc), Buffers};
+ {more_data, Buffers} ->
+ do_handle_fragments(Version, Fragments, Buffers, Acc);
+ {HsPacket, Buffers} ->
+ do_handle_fragments(Version, Fragments, Buffers, [HsPacket | Acc])
+ end.
+
+decode_handshake(Version, <<?BYTE(Type), Bin/binary>>) ->
+ decode_handshake(Version, Type, Bin).
+
+decode_handshake(_, ?HELLO_REQUEST, <<>>) ->
+ #hello_request{};
+decode_handshake(_Version, ?CLIENT_HELLO, <<?UINT24(_), ?UINT16(_),
+ ?UINT24(_), ?UINT24(_),
+ ?BYTE(Major), ?BYTE(Minor), Random:32/binary,
?BYTE(SID_length), Session_ID:SID_length/binary,
- ?BYTE(Cookie_length), Cookie:Cookie_length/binary,
+ ?BYTE(CookieLength), Cookie:CookieLength/binary,
?UINT16(Cs_length), CipherSuites:Cs_length/binary,
?BYTE(Cm_length), Comp_methods:Cm_length/binary,
Extensions/binary>>) ->
- DecodedExtensions = ssl_handshake:decode_hello_extensions(Extensions),
-
+ DecodedExtensions = ssl_handshake:decode_hello_extensions({client, Extensions}),
+
#client_hello{
client_version = {Major,Minor},
random = Random,
- session_id = Session_ID,
cookie = Cookie,
+ session_id = Session_ID,
cipher_suites = ssl_handshake:decode_suites('2_bytes', CipherSuites),
compression_methods = Comp_methods,
extensions = DecodedExtensions
- };
+ };
+
+decode_handshake(_Version, ?HELLO_VERIFY_REQUEST, <<?UINT24(_), ?UINT16(_),
+ ?UINT24(_), ?UINT24(_),
+ ?BYTE(Major), ?BYTE(Minor),
+ ?BYTE(CookieLength),
+ Cookie:CookieLength/binary>>) ->
+ #hello_verify_request{protocol_version = {Major, Minor},
+ cookie = Cookie};
+
+decode_handshake(Version, Tag, <<?UINT24(_), ?UINT16(_),
+ ?UINT24(_), ?UINT24(_), Msg/binary>>) ->
+ %% DTLS specifics stripped
+ decode_tls_thandshake(Version, Tag, Msg).
+
+decode_tls_thandshake(Version, Tag, Msg) ->
+ TLSVersion = dtls_v1:corresponding_tls_version(Version),
+ ssl_handshake:decode_handshake(TLSVersion, Tag, Msg).
+
+decode_handshake_fragments(<<>>) ->
+ [<<>>];
+decode_handshake_fragments(<<?BYTE(Type), ?UINT24(Length),
+ ?UINT16(MessageSeq),
+ ?UINT24(FragmentOffset), ?UINT24(FragmentLength),
+ Fragment:FragmentLength/binary, Rest/binary>>) ->
+ [#handshake_fragment{type = Type,
+ length = Length,
+ message_seq = MessageSeq,
+ fragment_offset = FragmentOffset,
+ fragment_length = FragmentLength,
+ fragment = Fragment} | decode_handshake_fragments(Rest)].
+
+reassemble(Version, #handshake_fragment{message_seq = Seq} = Fragment,
+ #protocol_buffers{dtls_handshake_next_seq = Seq,
+ dtls_handshake_next_fragments = Fragments0,
+ dtls_handshake_later_fragments = LaterFragments0} =
+ Buffers0)->
+ case reassemble_fragments(Fragment, Fragments0) of
+ {more_data, Fragments} ->
+ {more_data, Buffers0#protocol_buffers{dtls_handshake_next_fragments = Fragments}};
+ {raw, RawHandshake} ->
+ Handshake = decode_handshake(Version, RawHandshake),
+ {NextFragments, LaterFragments} = next_fragments(LaterFragments0),
+ {{Handshake, RawHandshake}, Buffers0#protocol_buffers{dtls_handshake_next_seq = Seq + 1,
+ dtls_handshake_next_fragments = NextFragments,
+ dtls_handshake_later_fragments = LaterFragments}}
+ end;
+reassemble(_, #handshake_fragment{message_seq = FragSeq} = Fragment,
+ #protocol_buffers{dtls_handshake_next_seq = Seq,
+ dtls_handshake_later_fragments = LaterFragments} = Buffers0) when FragSeq > Seq->
+ {more_data,
+ Buffers0#protocol_buffers{dtls_handshake_later_fragments = [Fragment | LaterFragments]}};
+reassemble(_, _, Buffers) ->
+ %% Disregard fragments FragSeq < Seq
+ {more_data, Buffers}.
+
+reassemble_fragments(Current, Fragments0) ->
+ [Frag1 | Frags] = lists:keysort(#handshake_fragment.fragment_offset, [Current | Fragments0]),
+ [Fragment | _] = Fragments = merge_fragment(Frag1, Frags),
+ case is_complete_handshake(Fragment) of
+ true ->
+ {raw, handshake_bin(Fragment)};
+ false ->
+ {more_data, Fragments}
+ end.
-decode_handshake(_Version, ?HELLO_VERIFY_REQUEST, <<?BYTE(Major), ?BYTE(Minor),
- ?BYTE(CookieLength), Cookie:CookieLength/binary>>) ->
+merge_fragment(Frag0, []) ->
+ [Frag0];
+merge_fragment(Frag0, [Frag1 | Rest]) ->
+ case merge_fragments(Frag0, Frag1) of
+ [_|_] = Frags ->
+ Frags ++ Rest;
+ Frag ->
+ merge_fragment(Frag, Rest)
+ end.
- #hello_verify_request{
- protocol_version = {Major,Minor},
- cookie = Cookie};
-decode_handshake(Version, Tag, Msg) ->
- ssl_handshake:decode_handshake(Version, Tag, Msg).
+is_complete_handshake(#handshake_fragment{length = Length, fragment_length = Length}) ->
+ true;
+is_complete_handshake(_) ->
+ false.
+
+next_fragments(LaterFragments) ->
+ case lists:keysort(#handshake_fragment.message_seq, LaterFragments) of
+ [] ->
+ {[], []};
+ [#handshake_fragment{message_seq = Seq} | _] = Fragments ->
+ split_frags(Fragments, Seq, [])
+ end.
-%% address_to_bin({A,B,C,D}, Port) ->
-%% <<0:80,16#ffff:16,A,B,C,D,Port:16>>;
-%% address_to_bin({A,B,C,D,E,F,G,H}, Port) ->
-%% <<A:16,B:16,C:16,D:16,E:16,F:16,G:16,H:16,Port:16>>.
+split_frags([#handshake_fragment{message_seq = Seq} = Frag | Rest], Seq, Acc) ->
+ split_frags(Rest, Seq, [Frag | Acc]);
+split_frags(Frags, _, Acc) ->
+ {lists:reverse(Acc), Frags}.
+
+
+%% Duplicate
+merge_fragments(#handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = PreviousLen,
+ fragment = PreviousData
+ } = Previous,
+ #handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = PreviousLen,
+ fragment = PreviousData}) ->
+ Previous;
+
+%% Lager fragment save new data
+merge_fragments(#handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = PreviousLen,
+ fragment = PreviousData
+ } = Previous,
+ #handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = CurrentLen,
+ fragment = CurrentData}) when CurrentLen > PreviousLen ->
+ NewLength = CurrentLen - PreviousLen,
+ <<_:PreviousLen/binary, NewData/binary>> = CurrentData,
+ Previous#handshake_fragment{
+ fragment_length = PreviousLen + NewLength,
+ fragment = <<PreviousData/binary, NewData/binary>>
+ };
+
+%% Smaller fragment
+merge_fragments(#handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = PreviousLen
+ } = Previous,
+ #handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = CurrentLen}) when CurrentLen < PreviousLen ->
+ Previous;
+%% Next fragment
+merge_fragments(#handshake_fragment{
+ fragment_offset = PreviousOffSet,
+ fragment_length = PreviousLen,
+ fragment = PreviousData
+ } = Previous,
+ #handshake_fragment{
+ fragment_offset = CurrentOffSet,
+ fragment_length = CurrentLen,
+ fragment = CurrentData}) when PreviousOffSet + PreviousLen == CurrentOffSet->
+ Previous#handshake_fragment{
+ fragment_length = PreviousLen + CurrentLen,
+ fragment = <<PreviousData/binary, CurrentData/binary>>};
+%% No merge there is a gap
+merge_fragments(Previous, Current) ->
+ [Previous, Current].
+
+handshake_bin(#handshake_fragment{
+ type = Type,
+ length = Len,
+ message_seq = Seq,
+ fragment_length = Len,
+ fragment_offset = 0,
+ fragment = Fragment}) ->
+ handshake_bin(Type, Len, Seq, Fragment).
+
+handshake_bin(Type, Length, Seq, FragmentData) ->
+ <<?BYTE(Type), ?UINT24(Length),
+ ?UINT16(Seq), ?UINT24(0), ?UINT24(Length),
+ FragmentData:Length/binary>>.