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authorAndreas Schultz <aschultz@tpip.net>2013-06-12 16:26:24 +0200
committerIngela Anderton Andin <ingela@erlang.org>2013-09-10 09:37:29 +0200
commitfb6ac178ac437fcc04f1675df75b0583c1d24ad7 (patch)
treebcd8072e85b2eeb43566f36fb7545ab3bd40ddd9 /lib/ssl
parentf3be514fd1e015f78a227d25c3471dbe2cfb3d51 (diff)
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ssl: Add DTLS record primitives
This code is to 99 % written by Andreas Schultz only some small changes to start integrating with OTPs DTLS solution.
Diffstat (limited to 'lib/ssl')
-rw-r--r--lib/ssl/src/dtls_record.erl322
-rw-r--r--lib/ssl/src/dtls_record.hrl12
-rw-r--r--lib/ssl/src/ssl_record.hrl29
-rw-r--r--lib/ssl/src/tls_record.hrl6
4 files changed, 351 insertions, 18 deletions
diff --git a/lib/ssl/src/dtls_record.erl b/lib/ssl/src/dtls_record.erl
index 2469a7d26c..98c60f599c 100644
--- a/lib/ssl/src/dtls_record.erl
+++ b/lib/ssl/src/dtls_record.erl
@@ -16,3 +16,325 @@
%%
%% %CopyrightEnd%
-module(dtls_record).
+
+-include("dtls_record.hrl").
+-include("ssl_internal.hrl").
+-include("ssl_alert.hrl").
+
+-export([init_connection_state_seq/2, current_connection_state_epoch/2,
+ set_connection_state_by_epoch/3, connection_state_by_epoch/3]).
+
+%% Handling of incoming data
+-export([get_dtls_records/2]).
+
+%% Misc.
+-export([protocol_version/1, lowest_protocol_version/2,
+ highest_protocol_version/1, supported_protocol_versions/0,
+ is_acceptable_version/2]).
+
+%%--------------------------------------------------------------------
+-spec init_connection_state_seq(tls_version(), #connection_states{}) ->
+ #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, _},
+ #connection_states{
+ current_read = Read = #connection_state{epoch = 0},
+ current_write = Write = #connection_state{epoch = 0}} = CS0) ->
+ CS0#connection_states{current_write =
+ Write#connection_state{
+ sequence_number = Read#connection_state.sequence_number}};
+init_connection_state_seq(_, CS) ->
+ CS.
+
+%%--------------------------------------------------------
+-spec current_connection_state_epoch(#connection_states{}, read | write) ->
+ integer().
+%%
+%% Description: Returns the epoch the connection_state record
+%% that is currently defined as the current conection state.
+%%--------------------------------------------------------------------
+current_connection_state_epoch(#connection_states{current_read = Current},
+ read) ->
+ Current#connection_state.epoch;
+current_connection_state_epoch(#connection_states{current_write = Current},
+ write) ->
+ Current#connection_state.epoch.
+
+%%--------------------------------------------------------------------
+
+-spec connection_state_by_epoch(#connection_states{}, integer(), read | write) ->
+ #connection_state{}.
+%%
+%% Description: Returns the instance of the connection_state record
+%% that is defined by the Epoch.
+%%--------------------------------------------------------------------
+connection_state_by_epoch(#connection_states{previous_read = CS}, Epoch, read)
+ when CS#connection_state.epoch == Epoch ->
+ CS;
+connection_state_by_epoch(#connection_states{current_read = CS}, Epoch, read)
+ when CS#connection_state.epoch == Epoch ->
+ CS;
+connection_state_by_epoch(#connection_states{pending_read = CS}, Epoch, read)
+ when CS#connection_state.epoch == Epoch ->
+ CS;
+connection_state_by_epoch(#connection_states{previous_write = CS}, Epoch, write)
+ when CS#connection_state.epoch == Epoch ->
+ CS;
+connection_state_by_epoch(#connection_states{current_write = CS}, Epoch, write)
+ when CS#connection_state.epoch == Epoch ->
+ CS;
+connection_state_by_epoch(#connection_states{pending_write = CS}, Epoch, write)
+ when CS#connection_state.epoch == Epoch ->
+ CS.
+
+%%--------------------------------------------------------------------
+-spec set_connection_state_by_epoch(#connection_states{},
+ #connection_state{}, read | write) -> ok.
+%%
+%% Description: Returns the instance of the connection_state record
+%% that is defined by the Epoch.
+%%--------------------------------------------------------------------
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{previous_read = CS},
+ NewCS = #connection_state{epoch = Epoch}, read)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{previous_read = NewCS};
+
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{current_read = CS},
+ NewCS = #connection_state{epoch = Epoch}, read)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{current_read = NewCS};
+
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{pending_read = CS},
+ NewCS = #connection_state{epoch = Epoch}, read)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{pending_read = NewCS};
+
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{previous_write = CS},
+ NewCS = #connection_state{epoch = Epoch}, write)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{previous_write = NewCS};
+
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{current_write = CS},
+ NewCS = #connection_state{epoch = Epoch}, write)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{current_write = NewCS};
+
+set_connection_state_by_epoch(ConnectionStates0 =
+ #connection_states{pending_write = CS},
+ NewCS = #connection_state{epoch = Epoch}, write)
+ when CS#connection_state.epoch == Epoch ->
+ ConnectionStates0#connection_states{pending_write = NewCS}.
+
+
+%%--------------------------------------------------------------------
+-spec protocol_version(tls_atom_version() | tls_version()) ->
+ tls_version() | tls_atom_version().
+%%
+%% Description: Creates a protocol version record from a version atom
+%% or vice versa.
+%%--------------------------------------------------------------------
+protocol_version('dtlsv1.2') ->
+ {254, 253};
+protocol_version(dtlsv1) ->
+ {254, 255};
+protocol_version({254, 253}) ->
+ 'dtlsv1.2';
+protocol_version({254, 255}) ->
+ dtlsv1.
+%%--------------------------------------------------------------------
+-spec lowest_protocol_version(tls_version(), tls_version()) -> tls_version().
+%%
+%% Description: Lowes protocol version of two given versions
+%%--------------------------------------------------------------------
+lowest_protocol_version(Version = {M, N}, {M, O}) when N > O ->
+ Version;
+lowest_protocol_version({M, _}, Version = {M, _}) ->
+ Version;
+lowest_protocol_version(Version = {M,_}, {N, _}) when M > N ->
+ Version;
+lowest_protocol_version(_,Version) ->
+ Version.
+%%--------------------------------------------------------------------
+-spec highest_protocol_version([tls_version()]) -> tls_version().
+%%
+%% Description: Highest protocol version present in a list
+%%--------------------------------------------------------------------
+highest_protocol_version([Ver | Vers]) ->
+ highest_protocol_version(Ver, Vers).
+
+highest_protocol_version(Version, []) ->
+ Version;
+highest_protocol_version(Version = {N, M}, [{N, O} | Rest]) when M < O ->
+ highest_protocol_version(Version, Rest);
+highest_protocol_version({M, _}, [Version = {M, _} | Rest]) ->
+ highest_protocol_version(Version, Rest);
+highest_protocol_version(Version = {M,_}, [{N,_} | Rest]) when M < N ->
+ highest_protocol_version(Version, Rest);
+highest_protocol_version(_, [Version | Rest]) ->
+ highest_protocol_version(Version, Rest).
+
+%%--------------------------------------------------------------------
+-spec get_dtls_records(binary(), binary()) -> {[binary()], binary()} | #alert{}.
+%%
+%% Description: Given old buffer and new data from UDP/SCTP, packs up a records
+%% and returns it as a list of tls_compressed binaries also returns leftover
+%% data
+%%--------------------------------------------------------------------
+get_dtls_records(Data, <<>>) ->
+ get_dtls_records_aux(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, record_seq = 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, record_seq = 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, record_seq = 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, record_seq = 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.
+
+%%--------------------------------------------------------------------
+-spec supported_protocol_versions() -> [tls_version()].
+%%
+%% Description: Protocol versions supported
+%%--------------------------------------------------------------------
+supported_protocol_versions() ->
+ Fun = fun(Version) ->
+ protocol_version(Version)
+ end,
+ case application:get_env(ssl, dtls_protocol_version) of
+ undefined ->
+ lists:map(Fun, supported_protocol_versions([]));
+ {ok, []} ->
+ lists:map(Fun, supported_protocol_versions([]));
+ {ok, Vsns} when is_list(Vsns) ->
+ supported_protocol_versions(Vsns);
+ {ok, Vsn} ->
+ supported_protocol_versions([Vsn])
+ end.
+
+supported_protocol_versions([]) ->
+ Vsns = supported_connection_protocol_versions([]),
+ application:set_env(ssl, dtls_protocol_version, Vsns),
+ Vsns;
+
+supported_protocol_versions([_|_] = Vsns) ->
+ Vsns.
+
+supported_connection_protocol_versions([]) ->
+ ?ALL_DATAGRAM_SUPPORTED_VERSIONS.
+
+%%--------------------------------------------------------------------
+-spec is_acceptable_version(tls_version(), Supported :: [tls_version()]) -> boolean().
+%%
+%% Description: ssl version 2 is not acceptable security risks are too big.
+%%
+%%--------------------------------------------------------------------
+is_acceptable_version(Version, Versions) ->
+ lists:member(Version, Versions).
+
+%%--------------------------------------------------------------------
+-spec clear_previous_epoch(#connection_states{}) ->
+ #connection_states{}.
+%%
+%% Description: Advance to min_read_epoch to the current read epoch.
+%%--------------------------------------------------------------------
+clear_previous_epoch(States =
+ #connection_states{current_read = Current}) ->
+ States#connection_states{min_read_epoch = Current#connection_state.epoch}.
+
+
+
+decipher(TLS=#ssl_tls{type=Type, version=Version={254, _},
+ epoch = Epoch, sequence = SeqNo,
+ fragment=Fragment}, CS0) ->
+ SP = CS0#connection_state.security_parameters,
+ BCA = SP#security_parameters.bulk_cipher_algorithm,
+ HashSz = SP#security_parameters.hash_size,
+ CipherS0 = CS0#connection_state.cipher_state,
+ case ssl_cipher:decipher(BCA, HashSz, CipherS0, Fragment, Version) of
+ {T, Mac, CipherS1} ->
+ CS1 = CS0#connection_state{cipher_state = CipherS1},
+ TLength = size(T),
+ MacHash = hash_with_seqno(CS1, Type, Version, Epoch, SeqNo, TLength, T),
+ case is_correct_mac(Mac, MacHash) of
+ true ->
+ {TLS#ssl_tls{fragment = T}, CS1};
+ false ->
+ ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC)
+ end;
+ #alert{} = Alert ->
+ Alert
+ end.
+
+hash_with_seqno(#connection_state{mac_secret = MacSecret,
+ security_parameters =
+ SecPars},
+ Type, Version = {254, _},
+ Epoch, SeqNo, Length, Fragment) ->
+ mac_hash(Version,
+ SecPars#security_parameters.mac_algorithm,
+ MacSecret, (Epoch bsl 48) + SeqNo, Type,
+ Length, Fragment).
+
+hash_and_bump_seqno(#connection_state{epoch = Epoch,
+ sequence_number = SeqNo,
+ mac_secret = MacSecret,
+ security_parameters =
+ SecPars} = CS0,
+ Type, Version = {254, _}, Length, Fragment) ->
+ Hash = mac_hash(Version,
+ SecPars#security_parameters.mac_algorithm,
+ MacSecret, (Epoch bsl 48) + SeqNo, Type,
+ Length, Fragment),
+ {Hash, CS0#connection_state{sequence_number = SeqNo+1}}.
diff --git a/lib/ssl/src/dtls_record.hrl b/lib/ssl/src/dtls_record.hrl
index e935d84bdf..c50550cc28 100644
--- a/lib/ssl/src/dtls_record.hrl
+++ b/lib/ssl/src/dtls_record.hrl
@@ -28,6 +28,18 @@
-include("ssl_record.hrl"). %% Common TLS and DTLS records and Constantes
+-define(INITIAL_BYTES, 5).
+
+-record(connection_states, {
+ min_read_epoch,
+ previous_read,
+ current_read,
+ pending_read,
+ previous_write,
+ current_write,
+ pending_write
+ }).
+
%% Used to handle tls_plain_text, tls_compressed and tls_cipher_text
-record(ssl_tls, {
diff --git a/lib/ssl/src/ssl_record.hrl b/lib/ssl/src/ssl_record.hrl
index 2fd17f9c35..8a6a211553 100644
--- a/lib/ssl/src/ssl_record.hrl
+++ b/lib/ssl/src/ssl_record.hrl
@@ -29,12 +29,17 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Connection states - RFC 4346 section 6.1
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
--record(connection_states, {
- current_read,
- pending_read,
- current_write,
- pending_write
+-record(connection_state, {
+ security_parameters,
+ compression_state,
+ cipher_state,
+ mac_secret,
+ epoch, %% Only used by DTLS
+ sequence_number,
+ %% RFC 5746
+ secure_renegotiation,
+ client_verify_data,
+ server_verify_data
}).
-record(security_parameters, {
@@ -56,18 +61,6 @@
exportable % boolean
}).
--record(connection_state, {
- security_parameters,
- compression_state,
- cipher_state,
- mac_secret,
- sequence_number,
- %% RFC 5746
- secure_renegotiation,
- client_verify_data,
- server_verify_data
- }).
-
-define(MAX_SEQENCE_NUMBER, 18446744073709552000). %% math:pow(2, 64) - 1 = 1.8446744073709552e19
%% Sequence numbers can not wrap so when max is about to be reached we should renegotiate.
%% We will renegotiate a little before so that there will be sequence numbers left
diff --git a/lib/ssl/src/tls_record.hrl b/lib/ssl/src/tls_record.hrl
index c9350fa137..0e3552bafa 100644
--- a/lib/ssl/src/tls_record.hrl
+++ b/lib/ssl/src/tls_record.hrl
@@ -27,6 +27,12 @@
-define(tls_record, true).
-include("ssl_record.hrl"). %% Common TLS and DTLS records and Constantes
+-record(connection_states, {
+ current_read,
+ pending_read,
+ current_write,
+ pending_write
+ }).
%% Used to handle tls_plain_text, tls_compressed and tls_cipher_text