Sign Up
Log In
Log In
or
Sign Up
Places
All Projects
Status Monitor
Collapse sidebar
home:Ledest:erlang:19
erlang
2476-dtls-Implement-replay-protection.patch
Overview
Repositories
Revisions
Requests
Users
Attributes
Meta
File 2476-dtls-Implement-replay-protection.patch of Package erlang
From 4fd3360bb68adb2ee942b3fbaeab7d766b6d3454 Mon Sep 17 00:00:00 2001 From: Ingela Anderton Andin <ingela@erlang.org> Date: Wed, 10 May 2017 23:36:44 +0200 Subject: [PATCH] dtls: Implement replay protection See RFC 6347 section 3.3 --- lib/ssl/src/dtls_connection.erl | 32 +++++++++++++++++------- lib/ssl/src/dtls_record.erl | 55 ++++++++++++++++++++++++++++++++++++----- 2 files changed, 72 insertions(+), 15 deletions(-) diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl index 9937373e6..b52896a45 100644 --- a/lib/ssl/src/dtls_connection.erl +++ b/lib/ssl/src/dtls_connection.erl @@ -688,16 +688,19 @@ next_record(#state{unprocessed_handshake_events = N} = State) when N > 0 -> {no_record, State#state{unprocessed_handshake_events = N-1}}; next_record(#state{protocol_buffers = - #protocol_buffers{dtls_cipher_texts = [CT | Rest]} + #protocol_buffers{dtls_cipher_texts = [#ssl_tls{epoch = Epoch} = CT | Rest]} = Buffers, - connection_states = ConnStates0} = State) -> - case dtls_record:decode_cipher_text(CT, ConnStates0) of - {Plain, ConnStates} -> - {Plain, State#state{protocol_buffers = - Buffers#protocol_buffers{dtls_cipher_texts = Rest}, - connection_states = ConnStates}}; - #alert{} = Alert -> - {Alert, State} + connection_states = ConnectionStates} = State) -> + CurrentRead = dtls_record:get_connection_state_by_epoch(Epoch, ConnectionStates, read), + case dtls_record:replay_detect(CT, CurrentRead) of + false -> + decode_cipher_text(State#state{connection_states = ConnectionStates}) ; + true -> + ct:pal("Replay detect", []), + %% Ignore replayed record + next_record(State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + connection_states = ConnectionStates}) end; next_record(#state{role = server, socket = {Listener, {Client, _}}, @@ -770,6 +773,17 @@ next_event(StateName, Record, {next_state, StateName, State, [{next_event, internal, Alert} | Actions]} end. +decode_cipher_text(#state{protocol_buffers = #protocol_buffers{dtls_cipher_texts = [ CT | Rest]} = Buffers, + connection_states = ConnStates0} = State) -> + case dtls_record:decode_cipher_text(CT, ConnStates0) of + {Plain, ConnStates} -> + {Plain, State#state{protocol_buffers = + Buffers#protocol_buffers{dtls_cipher_texts = Rest}, + connection_states = ConnStates}}; + #alert{} = Alert -> + {Alert, State} + end. + dtls_version(hello, Version, #state{role = server} = State) -> State#state{negotiated_version = Version}; %%Inital version dtls_version(_,_, State) -> diff --git a/lib/ssl/src/dtls_record.erl b/lib/ssl/src/dtls_record.erl index 6a418c6fb..8a7f8c1d0 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}. -- 2.13.0
Locations
Projects
Search
Status Monitor
Help
OpenBuildService.org
Documentation
API Documentation
Code of Conduct
Contact
Support
@OBShq
Terms
openSUSE Build Service is sponsored by
The Open Build Service is an
openSUSE project
.
Sign Up
Log In
Places
Places
All Projects
Status Monitor
