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author | Ingela Anderton Andin <[email protected]> | 2013-06-05 09:35:24 +0200 |
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committer | Ingela Anderton Andin <[email protected]> | 2013-06-05 09:35:24 +0200 |
commit | f509fb7cef82413b19db0734a314c216b30a415c (patch) | |
tree | 10cb58fe6a74ae33fab345f2042e5924119b2038 /lib/ssl/src/tls_record.erl | |
parent | d73dc3d3c6d85f0d2bb332458d5f52c576e27715 (diff) | |
parent | e7f8debed1ecd2b506b28d7aa068d409948130d2 (diff) | |
download | otp-f509fb7cef82413b19db0734a314c216b30a415c.tar.gz otp-f509fb7cef82413b19db0734a314c216b30a415c.tar.bz2 otp-f509fb7cef82413b19db0734a314c216b30a415c.zip |
Merge branch 'ia/ssl/prep-dtls' into maint
* ia/ssl/prep-dtls:
ssl: Structural perarparation to support DTLS
ssl: Rename ssl_certificate_db to ssl_pkix_db for clarity
Diffstat (limited to 'lib/ssl/src/tls_record.erl')
-rw-r--r-- | lib/ssl/src/tls_record.erl | 716 |
1 files changed, 716 insertions, 0 deletions
diff --git a/lib/ssl/src/tls_record.erl b/lib/ssl/src/tls_record.erl new file mode 100644 index 0000000000..1409a04763 --- /dev/null +++ b/lib/ssl/src/tls_record.erl @@ -0,0 +1,716 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2007-2013. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +%% +%%---------------------------------------------------------------------- +%% Purpose: Help functions for handling the SSL-Record protocol +%% +%%---------------------------------------------------------------------- + +-module(tls_record). + +-include("tls_record.hrl"). +-include("ssl_internal.hrl"). +-include("ssl_alert.hrl"). +-include("tls_handshake.hrl"). +-include("ssl_cipher.hrl"). + +%% Connection state handling +-export([init_connection_states/1, + current_connection_state/2, pending_connection_state/2, + update_security_params/3, + set_mac_secret/4, + set_master_secret/2, + activate_pending_connection_state/2, + set_pending_cipher_state/4, + set_renegotiation_flag/2, + set_client_verify_data/3, + set_server_verify_data/3]). + +%% Handling of incoming data +-export([get_tls_records/2]). + +%% Encoding records +-export([encode_handshake/3, encode_alert_record/3, + encode_change_cipher_spec/2, encode_data/3]). + +%% Decoding +-export([decode_cipher_text/2]). + +%% Misc. +-export([protocol_version/1, lowest_protocol_version/2, + highest_protocol_version/1, supported_protocol_versions/0, + is_acceptable_version/1, is_acceptable_version/2]). + +-export([compressions/0]). + +-compile(inline). + +-define(INITIAL_BYTES, 5). + +%%==================================================================== +%% Internal application API +%%==================================================================== + +%%-------------------------------------------------------------------- +-spec init_connection_states(client | server) -> #connection_states{}. +%% +%% Description: Creates a connection_states record with appropriate +%% values for the initial SSL connection setup. +%%-------------------------------------------------------------------- +init_connection_states(Role) -> + ConnectionEnd = record_protocol_role(Role), + Current = initial_connection_state(ConnectionEnd), + Pending = empty_connection_state(ConnectionEnd), + #connection_states{current_read = Current, + pending_read = Pending, + current_write = Current, + pending_write = Pending + }. + +%%-------------------------------------------------------------------- +-spec current_connection_state(#connection_states{}, read | write) -> + #connection_state{}. +%% +%% Description: Returns the instance of the connection_state record +%% that is currently defined as the current conection state. +%%-------------------------------------------------------------------- +current_connection_state(#connection_states{current_read = Current}, + read) -> + Current; +current_connection_state(#connection_states{current_write = Current}, + write) -> + Current. + +%%-------------------------------------------------------------------- +-spec pending_connection_state(#connection_states{}, read | write) -> + #connection_state{}. +%% +%% Description: Returns the instance of the connection_state record +%% that is currently defined as the pending conection state. +%%-------------------------------------------------------------------- +pending_connection_state(#connection_states{pending_read = Pending}, + read) -> + Pending; +pending_connection_state(#connection_states{pending_write = Pending}, + write) -> + Pending. + +%%-------------------------------------------------------------------- +-spec update_security_params(#security_parameters{}, #security_parameters{}, + #connection_states{}) -> #connection_states{}. +%% +%% Description: Creates a new instance of the connection_states record +%% where the pending states gets its security parameters updated. +%%-------------------------------------------------------------------- +update_security_params(ReadParams, WriteParams, States = + #connection_states{pending_read = Read, + pending_write = Write}) -> + States#connection_states{pending_read = + Read#connection_state{security_parameters = + ReadParams}, + pending_write = + Write#connection_state{security_parameters = + WriteParams} + }. +%%-------------------------------------------------------------------- +-spec set_mac_secret(binary(), binary(), client | server, + #connection_states{}) -> #connection_states{}. +%% +%% Description: update the mac_secret field in pending connection states +%%-------------------------------------------------------------------- +set_mac_secret(ClientWriteMacSecret, ServerWriteMacSecret, client, States) -> + set_mac_secret(ServerWriteMacSecret, ClientWriteMacSecret, States); +set_mac_secret(ClientWriteMacSecret, ServerWriteMacSecret, server, States) -> + set_mac_secret(ClientWriteMacSecret, ServerWriteMacSecret, States). + +set_mac_secret(ReadMacSecret, WriteMacSecret, + States = #connection_states{pending_read = Read, + pending_write = Write}) -> + States#connection_states{ + pending_read = Read#connection_state{mac_secret = ReadMacSecret}, + pending_write = Write#connection_state{mac_secret = WriteMacSecret} + }. + + +%%-------------------------------------------------------------------- +-spec set_master_secret(binary(), #connection_states{}) -> #connection_states{}. +%% +%% Description: Set master_secret in pending connection states +%%-------------------------------------------------------------------- +set_master_secret(MasterSecret, + States = #connection_states{pending_read = Read, + pending_write = Write}) -> + ReadSecPar = Read#connection_state.security_parameters, + Read1 = Read#connection_state{ + security_parameters = ReadSecPar#security_parameters{ + master_secret = MasterSecret}}, + WriteSecPar = Write#connection_state.security_parameters, + Write1 = Write#connection_state{ + security_parameters = WriteSecPar#security_parameters{ + master_secret = MasterSecret}}, + States#connection_states{pending_read = Read1, pending_write = Write1}. + +%%-------------------------------------------------------------------- +-spec set_renegotiation_flag(boolean(), #connection_states{}) -> #connection_states{}. +%% +%% Description: Set secure_renegotiation in pending connection states +%%-------------------------------------------------------------------- +set_renegotiation_flag(Flag, #connection_states{ + current_read = CurrentRead0, + current_write = CurrentWrite0, + pending_read = PendingRead0, + pending_write = PendingWrite0} + = ConnectionStates) -> + CurrentRead = CurrentRead0#connection_state{secure_renegotiation = Flag}, + CurrentWrite = CurrentWrite0#connection_state{secure_renegotiation = Flag}, + PendingRead = PendingRead0#connection_state{secure_renegotiation = Flag}, + PendingWrite = PendingWrite0#connection_state{secure_renegotiation = Flag}, + ConnectionStates#connection_states{current_read = CurrentRead, + current_write = CurrentWrite, + pending_read = PendingRead, + pending_write = PendingWrite}. + +%%-------------------------------------------------------------------- +-spec set_client_verify_data(current_read | current_write | current_both, + binary(), #connection_states{})-> + #connection_states{}. +%% +%% Description: Set verify data in connection states. +%%-------------------------------------------------------------------- +set_client_verify_data(current_read, Data, + #connection_states{current_read = CurrentRead0, + pending_write = PendingWrite0} + = ConnectionStates) -> + CurrentRead = CurrentRead0#connection_state{client_verify_data = Data}, + PendingWrite = PendingWrite0#connection_state{client_verify_data = Data}, + ConnectionStates#connection_states{current_read = CurrentRead, + pending_write = PendingWrite}; +set_client_verify_data(current_write, Data, + #connection_states{pending_read = PendingRead0, + current_write = CurrentWrite0} + = ConnectionStates) -> + PendingRead = PendingRead0#connection_state{client_verify_data = Data}, + CurrentWrite = CurrentWrite0#connection_state{client_verify_data = Data}, + ConnectionStates#connection_states{pending_read = PendingRead, + current_write = CurrentWrite}; +set_client_verify_data(current_both, Data, + #connection_states{current_read = CurrentRead0, + current_write = CurrentWrite0} + = ConnectionStates) -> + CurrentRead = CurrentRead0#connection_state{client_verify_data = Data}, + CurrentWrite = CurrentWrite0#connection_state{client_verify_data = Data}, + ConnectionStates#connection_states{current_read = CurrentRead, + current_write = CurrentWrite}. +%%-------------------------------------------------------------------- +-spec set_server_verify_data(current_read | current_write | current_both, + binary(), #connection_states{})-> + #connection_states{}. +%% +%% Description: Set verify data in pending connection states. +%%-------------------------------------------------------------------- +set_server_verify_data(current_write, Data, + #connection_states{pending_read = PendingRead0, + current_write = CurrentWrite0} + = ConnectionStates) -> + PendingRead = PendingRead0#connection_state{server_verify_data = Data}, + CurrentWrite = CurrentWrite0#connection_state{server_verify_data = Data}, + ConnectionStates#connection_states{pending_read = PendingRead, + current_write = CurrentWrite}; + +set_server_verify_data(current_read, Data, + #connection_states{current_read = CurrentRead0, + pending_write = PendingWrite0} + = ConnectionStates) -> + CurrentRead = CurrentRead0#connection_state{server_verify_data = Data}, + PendingWrite = PendingWrite0#connection_state{server_verify_data = Data}, + ConnectionStates#connection_states{current_read = CurrentRead, + pending_write = PendingWrite}; + +set_server_verify_data(current_both, Data, + #connection_states{current_read = CurrentRead0, + current_write = CurrentWrite0} + = ConnectionStates) -> + CurrentRead = CurrentRead0#connection_state{server_verify_data = Data}, + CurrentWrite = CurrentWrite0#connection_state{server_verify_data = Data}, + ConnectionStates#connection_states{current_read = CurrentRead, + current_write = CurrentWrite}. + +%%-------------------------------------------------------------------- +-spec activate_pending_connection_state(#connection_states{}, read | write) -> + #connection_states{}. +%% +%% Description: Creates a new instance of the connection_states record +%% where the pending state of <Type> has been activated. +%%-------------------------------------------------------------------- +activate_pending_connection_state(States = + #connection_states{pending_read = Pending}, + read) -> + NewCurrent = Pending#connection_state{sequence_number = 0}, + SecParams = Pending#connection_state.security_parameters, + ConnectionEnd = SecParams#security_parameters.connection_end, + EmptyPending = empty_connection_state(ConnectionEnd), + SecureRenegotation = NewCurrent#connection_state.secure_renegotiation, + NewPending = EmptyPending#connection_state{secure_renegotiation = SecureRenegotation}, + States#connection_states{current_read = NewCurrent, + pending_read = NewPending + }; + +activate_pending_connection_state(States = + #connection_states{pending_write = Pending}, + write) -> + NewCurrent = Pending#connection_state{sequence_number = 0}, + SecParams = Pending#connection_state.security_parameters, + ConnectionEnd = SecParams#security_parameters.connection_end, + EmptyPending = empty_connection_state(ConnectionEnd), + SecureRenegotation = NewCurrent#connection_state.secure_renegotiation, + NewPending = EmptyPending#connection_state{secure_renegotiation = SecureRenegotation}, + States#connection_states{current_write = NewCurrent, + pending_write = NewPending + }. + +%%-------------------------------------------------------------------- +-spec set_pending_cipher_state(#connection_states{}, #cipher_state{}, + #cipher_state{}, client | server) -> + #connection_states{}. +%% +%% Description: Set the cipher state in the specified pending connection state. +%%-------------------------------------------------------------------- +set_pending_cipher_state(#connection_states{pending_read = Read, + pending_write = Write} = States, + ClientState, ServerState, server) -> + States#connection_states{ + pending_read = Read#connection_state{cipher_state = ClientState}, + pending_write = Write#connection_state{cipher_state = ServerState}}; + +set_pending_cipher_state(#connection_states{pending_read = Read, + pending_write = Write} = States, + ClientState, ServerState, client) -> + States#connection_states{ + pending_read = Read#connection_state{cipher_state = ServerState}, + pending_write = Write#connection_state{cipher_state = ClientState}}. + +%%-------------------------------------------------------------------- +-spec get_tls_records(binary(), binary()) -> {[binary()], binary()} | #alert{}. +%% +%% Description: Given old buffer and new data from TCP, packs up a records +%% and returns it as a list of tls_compressed binaries also returns leftover +%% data +%%-------------------------------------------------------------------- +get_tls_records(Data, <<>>) -> + get_tls_records_aux(Data, []); +get_tls_records(Data, Buffer) -> + get_tls_records_aux(list_to_binary([Buffer, Data]), []). + +get_tls_records_aux(<<?BYTE(?APPLICATION_DATA),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Length), Data:Length/binary, Rest/binary>>, + Acc) -> + get_tls_records_aux(Rest, [#ssl_tls{type = ?APPLICATION_DATA, + version = {MajVer, MinVer}, + fragment = Data} | Acc]); +get_tls_records_aux(<<?BYTE(?HANDSHAKE),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Length), + Data:Length/binary, Rest/binary>>, Acc) -> + get_tls_records_aux(Rest, [#ssl_tls{type = ?HANDSHAKE, + version = {MajVer, MinVer}, + fragment = Data} | Acc]); +get_tls_records_aux(<<?BYTE(?ALERT),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Length), Data:Length/binary, + Rest/binary>>, Acc) -> + get_tls_records_aux(Rest, [#ssl_tls{type = ?ALERT, + version = {MajVer, MinVer}, + fragment = Data} | Acc]); +get_tls_records_aux(<<?BYTE(?CHANGE_CIPHER_SPEC),?BYTE(MajVer),?BYTE(MinVer), + ?UINT16(Length), Data:Length/binary, Rest/binary>>, + Acc) -> + get_tls_records_aux(Rest, [#ssl_tls{type = ?CHANGE_CIPHER_SPEC, + version = {MajVer, MinVer}, + fragment = Data} | Acc]); +%% Matches an ssl v2 client hello message. +%% The server must be able to receive such messages, from clients that +%% are willing to use ssl v3 or higher, but have ssl v2 compatibility. +get_tls_records_aux(<<1:1, Length0:15, Data0:Length0/binary, Rest/binary>>, + Acc) -> + case Data0 of + <<?BYTE(?CLIENT_HELLO), ?BYTE(MajVer), ?BYTE(MinVer), _/binary>> -> + Length = Length0-1, + <<?BYTE(_), Data1:Length/binary>> = Data0, + Data = <<?BYTE(?CLIENT_HELLO), ?UINT24(Length), Data1/binary>>, + get_tls_records_aux(Rest, [#ssl_tls{type = ?HANDSHAKE, + version = {MajVer, MinVer}, + fragment = Data} | Acc]); + _ -> + ?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE) + + end; + +get_tls_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_tls_records_aux(<<1:1, Length0:15, _/binary>>,_Acc) + when Length0 > ?MAX_CIPHER_TEXT_LENGTH -> + ?ALERT_REC(?FATAL, ?RECORD_OVERFLOW); + +get_tls_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 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('tlsv1.2') -> + {3, 3}; +protocol_version('tlsv1.1') -> + {3, 2}; +protocol_version(tlsv1) -> + {3, 1}; +protocol_version(sslv3) -> + {3, 0}; +protocol_version(sslv2) -> %% Backwards compatibility + {2, 0}; +protocol_version({3, 3}) -> + 'tlsv1.2'; +protocol_version({3, 2}) -> + 'tlsv1.1'; +protocol_version({3, 1}) -> + tlsv1; +protocol_version({3, 0}) -> + sslv3. +%%-------------------------------------------------------------------- +-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([]) -> + highest_protocol_version(); +highest_protocol_version(Versions) -> + [Ver | Vers] = Versions, + 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 supported_protocol_versions() -> [tls_version()]. +%% +%% Description: Protocol versions supported +%%-------------------------------------------------------------------- +supported_protocol_versions() -> + Fun = fun(Version) -> + protocol_version(Version) + end, + case application:get_env(ssl, protocol_version) of + undefined -> + lists:map(Fun, supported_protocol_versions([])); + {ok, []} -> + lists:map(Fun, supported_protocol_versions([])); + {ok, Vsns} when is_list(Vsns) -> + Versions = lists:filter(fun is_acceptable_version/1, lists:map(Fun, Vsns)), + supported_protocol_versions(Versions); + {ok, Vsn} -> + Versions = lists:filter(fun is_acceptable_version/1, [Fun(Vsn)]), + supported_protocol_versions(Versions) + end. + +supported_protocol_versions([]) -> + Vsns = case sufficient_tlsv1_2_crypto_support() of + true -> + ?ALL_SUPPORTED_VERSIONS; + false -> + ?MIN_SUPPORTED_VERSIONS + end, + application:set_env(ssl, protocol_version, Vsns), + Vsns; + +supported_protocol_versions([_|_] = Vsns) -> + Vsns. + +%%-------------------------------------------------------------------- +-spec is_acceptable_version(tls_version()) -> boolean(). +-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({N,_}) + when N >= ?LOWEST_MAJOR_SUPPORTED_VERSION -> + true; +is_acceptable_version(_) -> + false. + +is_acceptable_version({N,_} = Version, Versions) + when N >= ?LOWEST_MAJOR_SUPPORTED_VERSION -> + lists:member(Version, Versions); +is_acceptable_version(_,_) -> + false. + +%%-------------------------------------------------------------------- +-spec compressions() -> [binary()]. +%% +%% Description: return a list of compressions supported (currently none) +%%-------------------------------------------------------------------- +compressions() -> + [?byte(?NULL)]. + +%%-------------------------------------------------------------------- +-spec decode_cipher_text(#ssl_tls{}, #connection_states{}) -> + {#ssl_tls{}, #connection_states{}}| #alert{}. +%% +%% Description: Decode cipher text +%%-------------------------------------------------------------------- +decode_cipher_text(CipherText, ConnnectionStates0) -> + ReadState0 = ConnnectionStates0#connection_states.current_read, + #connection_state{compression_state = CompressionS0, + security_parameters = SecParams} = ReadState0, + CompressAlg = SecParams#security_parameters.compression_algorithm, + case decipher(CipherText, ReadState0) of + {Compressed, ReadState1} -> + {Plain, CompressionS1} = uncompress(CompressAlg, + Compressed, CompressionS0), + ConnnectionStates = ConnnectionStates0#connection_states{ + current_read = ReadState1#connection_state{ + compression_state = CompressionS1}}, + {Plain, ConnnectionStates}; + #alert{} = Alert -> + Alert + end. +%%-------------------------------------------------------------------- +-spec encode_data(binary(), tls_version(), #connection_states{}) -> + {iolist(), #connection_states{}}. +%% +%% Description: Encodes data to send on the ssl-socket. +%%-------------------------------------------------------------------- +encode_data(Frag, Version, + #connection_states{current_write = #connection_state{ + security_parameters = + #security_parameters{bulk_cipher_algorithm = BCA}}} = + ConnectionStates) -> + Data = split_bin(Frag, ?MAX_PLAIN_TEXT_LENGTH, Version, BCA), + encode_iolist(?APPLICATION_DATA, Data, Version, ConnectionStates). + +%%-------------------------------------------------------------------- +-spec encode_handshake(iolist(), tls_version(), #connection_states{}) -> + {iolist(), #connection_states{}}. +%% +%% Description: Encodes a handshake message to send on the ssl-socket. +%%-------------------------------------------------------------------- +encode_handshake(Frag, Version, ConnectionStates) -> + encode_plain_text(?HANDSHAKE, Version, Frag, ConnectionStates). + +%%-------------------------------------------------------------------- +-spec encode_alert_record(#alert{}, tls_version(), #connection_states{}) -> + {iolist(), #connection_states{}}. +%% +%% Description: Encodes an alert message to send on the ssl-socket. +%%-------------------------------------------------------------------- +encode_alert_record(#alert{level = Level, description = Description}, + Version, ConnectionStates) -> + encode_plain_text(?ALERT, Version, <<?BYTE(Level), ?BYTE(Description)>>, + ConnectionStates). + +%%-------------------------------------------------------------------- +-spec encode_change_cipher_spec(tls_version(), #connection_states{}) -> + {iolist(), #connection_states{}}. +%% +%% Description: Encodes a change_cipher_spec-message to send on the ssl socket. +%%-------------------------------------------------------------------- +encode_change_cipher_spec(Version, ConnectionStates) -> + encode_plain_text(?CHANGE_CIPHER_SPEC, Version, <<1:8>>, ConnectionStates). + +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +encode_iolist(Type, Data, Version, ConnectionStates0) -> + {ConnectionStates, EncodedMsg} = + lists:foldl(fun(Text, {CS0, Encoded}) -> + {Enc, CS1} = encode_plain_text(Type, Version, Text, CS0), + {CS1, [Enc | Encoded]} + end, {ConnectionStates0, []}, Data), + {lists:reverse(EncodedMsg), ConnectionStates}. + +highest_protocol_version() -> + highest_protocol_version(supported_protocol_versions()). + +initial_connection_state(ConnectionEnd) -> + #connection_state{security_parameters = + initial_security_params(ConnectionEnd), + sequence_number = 0 + }. + +initial_security_params(ConnectionEnd) -> + SecParams = #security_parameters{connection_end = ConnectionEnd, + compression_algorithm = ?NULL}, + ssl_cipher:security_parameters(highest_protocol_version(), ?TLS_NULL_WITH_NULL_NULL, + SecParams). + +empty_connection_state(ConnectionEnd) -> + SecParams = empty_security_params(ConnectionEnd), + #connection_state{security_parameters = SecParams}. + +empty_security_params(ConnectionEnd = ?CLIENT) -> + #security_parameters{connection_end = ConnectionEnd, + client_random = random()}; +empty_security_params(ConnectionEnd = ?SERVER) -> + #security_parameters{connection_end = ConnectionEnd, + server_random = random()}. +random() -> + Secs_since_1970 = calendar:datetime_to_gregorian_seconds( + calendar:universal_time()) - 62167219200, + Random_28_bytes = crypto:rand_bytes(28), + <<?UINT32(Secs_since_1970), Random_28_bytes/binary>>. + +record_protocol_role(client) -> + ?CLIENT; +record_protocol_role(server) -> + ?SERVER. + +%% 1/n-1 splitting countermeasure Rizzo/Duong-Beast, RC4 chiphers are not vulnerable to this attack. +split_bin(<<FirstByte:8, Rest/binary>>, ChunkSize, Version, BCA) when BCA =/= ?RC4 andalso ({3, 1} == Version orelse + {3, 0} == Version) -> + do_split_bin(Rest, ChunkSize, [[FirstByte]]); +split_bin(Bin, ChunkSize, _, _) -> + do_split_bin(Bin, ChunkSize, []). + +do_split_bin(<<>>, _, Acc) -> + lists:reverse(Acc); +do_split_bin(Bin, ChunkSize, Acc) -> + case Bin of + <<Chunk:ChunkSize/binary, Rest/binary>> -> + do_split_bin(Rest, ChunkSize, [Chunk | Acc]); + _ -> + lists:reverse(Acc, [Bin]) + end. + +encode_plain_text(Type, Version, Data, ConnectionStates) -> + #connection_states{current_write=#connection_state{ + compression_state=CompS0, + security_parameters= + #security_parameters{compression_algorithm=CompAlg} + }=CS0} = ConnectionStates, + {Comp, CompS1} = compress(CompAlg, Data, CompS0), + CS1 = CS0#connection_state{compression_state = CompS1}, + {CipherText, CS2} = cipher(Type, Version, Comp, CS1), + CTBin = encode_tls_cipher_text(Type, Version, CipherText), + {CTBin, ConnectionStates#connection_states{current_write = CS2}}. + +encode_tls_cipher_text(Type, {MajVer, MinVer}, Fragment) -> + Length = erlang:iolist_size(Fragment), + [<<?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer), ?UINT16(Length)>>, Fragment]. + +cipher(Type, Version, Fragment, CS0) -> + Length = erlang:iolist_size(Fragment), + {MacHash, CS1=#connection_state{cipher_state = CipherS0, + security_parameters= + #security_parameters{bulk_cipher_algorithm = + BCA} + }} = + hash_and_bump_seqno(CS0, Type, Version, Length, Fragment), + {Ciphered, CipherS1} = ssl_cipher:cipher(BCA, CipherS0, MacHash, Fragment, Version), + CS2 = CS1#connection_state{cipher_state=CipherS1}, + {Ciphered, CS2}. + +decipher(TLS=#ssl_tls{type=Type, version=Version, 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, CS2} = hash_and_bump_seqno(CS1, Type, Version, TLength, T), + case is_correct_mac(Mac, MacHash) of + true -> + {TLS#ssl_tls{fragment = T}, CS2}; + false -> + ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) + end; + #alert{} = Alert -> + Alert + end. + +uncompress(?NULL, Data = #ssl_tls{type = _Type, + version = _Version, + fragment = _Fragment}, CS) -> + {Data, CS}. + +compress(?NULL, Data, CS) -> + {Data, CS}. + +hash_and_bump_seqno(#connection_state{sequence_number = SeqNo, + mac_secret = MacSecret, + security_parameters = + SecPars} = CS0, + Type, Version, Length, Fragment) -> + Hash = mac_hash(Version, + SecPars#security_parameters.mac_algorithm, + MacSecret, SeqNo, Type, + Length, Fragment), + {Hash, CS0#connection_state{sequence_number = SeqNo+1}}. + +is_correct_mac(Mac, Mac) -> + true; +is_correct_mac(_M,_H) -> + false. + +mac_hash({_,_}, ?NULL, _MacSecret, _SeqNo, _Type, + _Length, _Fragment) -> + <<>>; +mac_hash({3, 0}, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) -> + ssl_ssl3:mac_hash(MacAlg, MacSecret, SeqNo, Type, Length, Fragment); +mac_hash({3, N} = Version, MacAlg, MacSecret, SeqNo, Type, Length, Fragment) + when N =:= 1; N =:= 2; N =:= 3 -> + ssl_tls1:mac_hash(MacAlg, MacSecret, SeqNo, Type, Version, + Length, Fragment). + +sufficient_tlsv1_2_crypto_support() -> + CryptoSupport = crypto:supports(), + proplists:get_bool(sha256, proplists:get_value(hashs, CryptoSupport)). |