From 5093b28115a674bfa26b06239f2c28981cbf73c2 Mon Sep 17 00:00:00 2001 From: Andreas Schultz Date: Thu, 7 Jan 2016 15:06:09 +0100 Subject: dtls: rework/simplify DTLS fragment decoder changed: * initialize deocder state when needed * remove retransmission indicator support --- lib/ssl/src/dtls_connection.hrl | 1 + lib/ssl/src/dtls_handshake.erl | 78 ++++++++++++++++++++--------------------- 2 files changed, 39 insertions(+), 40 deletions(-) (limited to 'lib') diff --git a/lib/ssl/src/dtls_connection.hrl b/lib/ssl/src/dtls_connection.hrl index 69137b520b..ee3daa3c14 100644 --- a/lib/ssl/src/dtls_connection.hrl +++ b/lib/ssl/src/dtls_connection.hrl @@ -31,6 +31,7 @@ -record(protocol_buffers, { dtls_packets = [], %%::[binary()], % Not yet handled decode ssl/tls packets. dtls_record_buffer = <<>>, %%:: binary(), % Buffer of incomplete records + dtls_fragment_state, %%:: [], % DTLS fragments dtls_handshake_buffer = <<>>, %%:: binary(), % Buffer of incomplete handshakes dtls_cipher_texts = [], %%:: [binary()], dtls_cipher_texts_next %%:: [binary()] % Received for Epoch not yet active diff --git a/lib/ssl/src/dtls_handshake.erl b/lib/ssl/src/dtls_handshake.erl index dbb03096ab..a22961ccca 100644 --- a/lib/ssl/src/dtls_handshake.erl +++ b/lib/ssl/src/dtls_handshake.erl @@ -25,7 +25,7 @@ -export([client_hello/8, client_hello/9, hello/4, get_dtls_handshake/2, - %%dtls_handshake_new_flight/1, dtls_handshake_new_epoch/1, + dtls_handshake_new_flight/1, dtls_handshake_new_epoch/1, encode_handshake/3]). -type dtls_handshake() :: #client_hello{} | #hello_verify_request{} | @@ -141,39 +141,47 @@ encode_handshake(Handshake, Version, MsgSeq) -> {Enc, Frag}. %%-------------------------------------------------------------------- --spec get_dtls_handshake(#ssl_tls{}, #dtls_hs_state{} | binary()) -> +-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(Record, <<>>) -> - get_dtls_handshake_aux(Record, #dtls_hs_state{}); %% Init handshake state!? -get_dtls_handshake(Record, HsState) -> - get_dtls_handshake_aux(Record, HsState). +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). -%% %%-------------------------------------------------------------------- -%% -spec dtls_handshake_new_epoch(#dtls_hs_state{}) -> #dtls_hs_state{}. -%% %% -%% %% Description: Reset the DTLS decoder state for a new Epoch -%% %%-------------------------------------------------------------------- +%%-------------------------------------------------------------------- +-spec dtls_handshake_new_epoch(#dtls_hs_state{}) -> #dtls_hs_state{}. +%% +%% Description: Reset the DTLS decoder state for a new Epoch +%%-------------------------------------------------------------------- %% 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 = []}. +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 = []}. %%-------------------------------------------------------------------- %%% Internal functions @@ -189,6 +197,9 @@ 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) -> @@ -203,25 +214,18 @@ get_dtls_handshake_aux(Version, SeqNo, case reassemble_dtls_fragment(SeqNo, Type, Length, MessageSeq, FragmentOffset, FragmentLength, Body, HsState0) of - {retransmit, HsState1} -> - case Rest of - <<>> -> - {retransmit, HsState1}; - _ -> - get_dtls_handshake_aux(Version, SeqNo, Rest, HsState1) - end; {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) -> - {lists:reverse(HsState#dtls_hs_state.completed), - HsState#dtls_hs_state{completed = []}}. + HsState. dec_dtls_fragment(Version, SeqNo, Type, Length, MessageSeq, MsgBody, HsState = #dtls_hs_state{highest_record_seq = HighestSeqNo, completed = Acc}) -> @@ -287,12 +291,6 @@ reassemble_dtls_fragment(SeqNo, _Type, Length, MessageSeq, 0, Length, 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 -> - {retransmit, HsState}; - reassemble_dtls_fragment(_SeqNo, _Type, Length, MessageSeq, 0, Length, _Body, HsState = #dtls_hs_state{current_read_seq = CurrentReadSeq}) when MessageSeq < CurrentReadSeq -> -- cgit v1.2.3