diff options
Diffstat (limited to 'lib/ssl/src/tls_record.erl')
-rw-r--r-- | lib/ssl/src/tls_record.erl | 259 |
1 files changed, 162 insertions, 97 deletions
diff --git a/lib/ssl/src/tls_record.erl b/lib/ssl/src/tls_record.erl index 993a1622fe..188ec6809d 100644 --- a/lib/ssl/src/tls_record.erl +++ b/lib/ssl/src/tls_record.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2007-2016. All Rights Reserved. +%% Copyright Ericsson AB 2007-2017. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -32,21 +32,21 @@ -include("ssl_cipher.hrl"). %% Handling of incoming data --export([get_tls_records/2, init_connection_states/2]). +-export([get_tls_records/3, init_connection_states/2]). %% Encoding TLS records -export([encode_handshake/3, encode_alert_record/3, encode_change_cipher_spec/2, encode_data/3]). -export([encode_plain_text/4]). +%% Decoding +-export([decode_cipher_text/3]). + %% Protocol version handling -export([protocol_version/1, lowest_protocol_version/1, lowest_protocol_version/2, highest_protocol_version/1, highest_protocol_version/2, is_higher/2, supported_protocol_versions/0, - is_acceptable_version/1, is_acceptable_version/2]). - -%% Decoding --export([decode_cipher_text/3]). + is_acceptable_version/1, is_acceptable_version/2, hello_version/2]). -export_type([tls_version/0, tls_atom_version/0]). @@ -56,13 +56,12 @@ -compile(inline). %%==================================================================== -%% Internal application API +%% Handling of incoming data %%==================================================================== %%-------------------------------------------------------------------- -spec init_connection_states(client | server, one_n_minus_one | zero_n | disabled) -> ssl_record:connection_states(). -%% % - % +%% %% Description: Creates a connection_states record with appropriate %% values for the initial SSL connection setup. %%-------------------------------------------------------------------- @@ -76,16 +75,29 @@ init_connection_states(Role, BeastMitigation) -> pending_write => Pending}. %%-------------------------------------------------------------------- --spec get_tls_records(binary(), binary()) -> {[binary()], binary()} | #alert{}. +-spec get_tls_records(binary(), [tls_version()], binary()) -> {[binary()], binary()} | #alert{}. %% %% and returns it as a list of tls_compressed binaries also returns leftover %% Description: Given old buffer and new data from TCP, packs up a records %% 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(Data, Versions, Buffer) -> + BinData = list_to_binary([Buffer, Data]), + case erlang:byte_size(BinData) of + N when N >= 3 -> + case assert_version(BinData, Versions) of + true -> + get_tls_records_aux(BinData, []); + false -> + ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) + end; + _ -> + get_tls_records_aux(BinData, []) + end. + +%%==================================================================== +%% Encoding +%%==================================================================== %%-------------------------------------------------------------------- -spec encode_handshake(iolist(), tls_version(), ssl_record:connection_states()) -> @@ -141,6 +153,74 @@ encode_data(Frag, Version, Data = split_bin(Frag, ?MAX_PLAIN_TEXT_LENGTH, Version, BCA, BeastMitigation), encode_iolist(?APPLICATION_DATA, Data, Version, ConnectionStates). +%%==================================================================== +%% Decoding +%%==================================================================== + +%%-------------------------------------------------------------------- +-spec decode_cipher_text(#ssl_tls{}, ssl_record:connection_states(), boolean()) -> + {#ssl_tls{}, ssl_record:connection_states()}| #alert{}. +%% +%% Description: Decode cipher text +%%-------------------------------------------------------------------- +decode_cipher_text(#ssl_tls{type = Type, version = Version, + fragment = CipherFragment} = CipherText, + #{current_read := + #{compression_state := CompressionS0, + sequence_number := Seq, + cipher_state := CipherS0, + security_parameters := + #security_parameters{ + cipher_type = ?AEAD, + bulk_cipher_algorithm = + BulkCipherAlgo, + compression_algorithm = CompAlg} + } = ReadState0} = ConnnectionStates0, _) -> + AAD = calc_aad(Type, Version, ReadState0), + case ssl_cipher:decipher_aead(BulkCipherAlgo, CipherS0, Seq, AAD, CipherFragment, Version) of + {PlainFragment, CipherS1} -> + {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, + PlainFragment, CompressionS0), + ConnnectionStates = ConnnectionStates0#{ + current_read => ReadState0#{ + cipher_state => CipherS1, + sequence_number => Seq + 1, + compression_state => CompressionS1}}, + {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; + #alert{} = Alert -> + Alert + end; + +decode_cipher_text(#ssl_tls{type = Type, version = Version, + fragment = CipherFragment} = CipherText, + #{current_read := + #{compression_state := CompressionS0, + sequence_number := Seq, + security_parameters := + #security_parameters{compression_algorithm = CompAlg} + } = ReadState0} = ConnnectionStates0, PaddingCheck) -> + case ssl_record:decipher(Version, CipherFragment, ReadState0, PaddingCheck) of + {PlainFragment, Mac, ReadState1} -> + MacHash = ssl_cipher:calc_mac_hash(Type, Version, PlainFragment, ReadState1), + case ssl_record:is_correct_mac(Mac, MacHash) of + true -> + {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, + PlainFragment, CompressionS0), + ConnnectionStates = ConnnectionStates0#{ + current_read => ReadState1#{ + sequence_number => Seq + 1, + compression_state => CompressionS1}}, + {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; + false -> + ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) + end; + #alert{} = Alert -> + Alert + end. + +%%==================================================================== +%% Protocol version handling +%%==================================================================== %%-------------------------------------------------------------------- -spec protocol_version(tls_atom_version() | tls_version()) -> @@ -277,11 +357,7 @@ supported_protocol_versions([_|_] = Vsns) -> NewVsns end end. -%%-------------------------------------------------------------------- -%% -%% Description: ssl version 2 is not acceptable security risks are too big. -%% -%%-------------------------------------------------------------------- + -spec is_acceptable_version(tls_version()) -> boolean(). is_acceptable_version({N,_}) when N >= ?LOWEST_MAJOR_SUPPORTED_VERSION -> @@ -296,6 +372,12 @@ is_acceptable_version({N,_} = Version, Versions) is_acceptable_version(_,_) -> false. +-spec hello_version(tls_version(), [tls_version()]) -> tls_version(). +hello_version(Version, _) when Version >= {3, 3} -> + Version; +hello_version(_, Versions) -> + lowest_protocol_version(Versions). + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- @@ -312,6 +394,19 @@ initial_connection_state(ConnectionEnd, BeastMitigation) -> server_verify_data => undefined }. +assert_version(<<1:1, Length0:15, Data0:Length0/binary, _/binary>>, Versions) -> + case Data0 of + <<?BYTE(?CLIENT_HELLO), ?BYTE(Major), ?BYTE(Minor), _/binary>> -> + %% First check v2_hello_compatible mode is active + lists:member({2,0}, Versions) andalso + %% andalso we want to negotiate higher version + lists:member({Major, Minor}, Versions -- [{2,0}]); + _ -> + false + end; +assert_version(<<?BYTE(_), ?BYTE(MajVer), ?BYTE(MinVer), _/binary>>, Versions) -> + is_acceptable_version({MajVer, MinVer}, Versions). + get_tls_records_aux(<<?BYTE(?APPLICATION_DATA),?BYTE(MajVer),?BYTE(MinVer), ?UINT16(Length), Data:Length/binary, Rest/binary>>, Acc) -> @@ -355,10 +450,9 @@ get_tls_records_aux(<<1:1, Length0:15, Data0:Length0/binary, Rest/binary>>, end; get_tls_records_aux(<<0:1, _CT:7, ?BYTE(_MajVer), ?BYTE(_MinVer), - ?UINT16(Length), _/binary>>, + ?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); @@ -370,37 +464,17 @@ get_tls_records_aux(Data, Acc) -> false -> ?ALERT_REC(?FATAL, ?UNEXPECTED_MESSAGE) end. - +%%-------------------------------------------------------------------- encode_plain_text(Type, Version, Data, #{current_write := Write0} = ConnectionStates) -> - {CipherFragment, Write1} = ssl_record:encode_plain_text(Type, Version, Data, Write0), + {CipherFragment, Write1} = do_encode_plain_text(Type, Version, Data, Write0), {CipherText, Write} = encode_tls_cipher_text(Type, Version, CipherFragment, Write1), {CipherText, ConnectionStates#{current_write => Write}}. -lowest_list_protocol_version(Ver, []) -> - Ver; -lowest_list_protocol_version(Ver1, [Ver2 | Rest]) -> - lowest_list_protocol_version(lowest_protocol_version(Ver1, Ver2), Rest). - -highest_list_protocol_version(Ver, []) -> - Ver; -highest_list_protocol_version(Ver1, [Ver2 | Rest]) -> - highest_list_protocol_version(highest_protocol_version(Ver1, Ver2), Rest). - encode_tls_cipher_text(Type, {MajVer, MinVer}, Fragment, #{sequence_number := Seq} = Write) -> Length = erlang:iolist_size(Fragment), {[<<?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer), ?UINT16(Length)>>, Fragment], Write#{sequence_number => Seq +1}}. -highest_protocol_version() -> - highest_protocol_version(supported_protocol_versions()). - -lowest_protocol_version() -> - lowest_protocol_version(supported_protocol_versions()). - -sufficient_tlsv1_2_crypto_support() -> - CryptoSupport = crypto:supports(), - proplists:get_bool(sha256, proplists:get_value(hashs, CryptoSupport)). - encode_iolist(Type, Data, Version, ConnectionStates0) -> {ConnectionStates, EncodedMsg} = lists:foldl(fun(Text, {CS0, Encoded}) -> @@ -409,6 +483,31 @@ encode_iolist(Type, Data, Version, ConnectionStates0) -> {CS1, [Enc | Encoded]} end, {ConnectionStates0, []}, Data), {lists:reverse(EncodedMsg), ConnectionStates}. +%%-------------------------------------------------------------------- +do_encode_plain_text(Type, Version, Data, #{compression_state := CompS0, + security_parameters := + #security_parameters{ + cipher_type = ?AEAD, + compression_algorithm = CompAlg} + } = WriteState0) -> + {Comp, CompS1} = ssl_record:compress(CompAlg, Data, CompS0), + WriteState1 = WriteState0#{compression_state => CompS1}, + AAD = calc_aad(Type, Version, WriteState1), + ssl_record:cipher_aead(Version, Comp, WriteState1, AAD); +do_encode_plain_text(Type, Version, Data, #{compression_state := CompS0, + security_parameters := + #security_parameters{compression_algorithm = CompAlg} + }= WriteState0) -> + {Comp, CompS1} = ssl_record:compress(CompAlg, Data, CompS0), + WriteState1 = WriteState0#{compression_state => CompS1}, + MacHash = ssl_cipher:calc_mac_hash(Type, Version, Comp, WriteState1), + ssl_record:cipher(Version, Comp, WriteState1, MacHash); +do_encode_plain_text(_,_,_,CS) -> + exit({cs, CS}). +%%-------------------------------------------------------------------- +calc_aad(Type, {MajVer, MinVer}, + #{sequence_number := SeqNo}) -> + <<?UINT64(SeqNo), ?BYTE(Type), ?BYTE(MajVer), ?BYTE(MinVer)>>. %% 1/n-1 splitting countermeasure Rizzo/Duong-Beast, RC4 chiphers are %% not vulnerable to this attack. @@ -434,59 +533,25 @@ do_split_bin(Bin, ChunkSize, Acc) -> _ -> lists:reverse(Acc, [Bin]) end. - %%-------------------------------------------------------------------- --spec decode_cipher_text(#ssl_tls{}, ssl_record:connection_states(), boolean()) -> - {#ssl_tls{}, ssl_record:connection_states()}| #alert{}. -%% -%% Description: Decode cipher text -%%-------------------------------------------------------------------- -decode_cipher_text(#ssl_tls{type = Type, version = Version, - fragment = CipherFragment} = CipherText, - #{current_read := - #{compression_state := CompressionS0, - sequence_number := Seq, - security_parameters := - #security_parameters{ - cipher_type = ?AEAD, - compression_algorithm = CompAlg} - } = ReadState0} = ConnnectionStates0, _) -> - AAD = ssl_cipher:calc_aad(Type, Version, ReadState0), - case ssl_record:decipher_aead(Version, CipherFragment, ReadState0, AAD) of - {PlainFragment, ReadState1} -> - {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, - PlainFragment, CompressionS0), - ConnnectionStates = ConnnectionStates0#{ - current_read => ReadState1#{sequence_number => Seq + 1, - compression_state => CompressionS1}}, - {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; - #alert{} = Alert -> - Alert - end; +lowest_list_protocol_version(Ver, []) -> + Ver; +lowest_list_protocol_version(Ver1, [Ver2 | Rest]) -> + lowest_list_protocol_version(lowest_protocol_version(Ver1, Ver2), Rest). + +highest_list_protocol_version(Ver, []) -> + Ver; +highest_list_protocol_version(Ver1, [Ver2 | Rest]) -> + highest_list_protocol_version(highest_protocol_version(Ver1, Ver2), Rest). + +highest_protocol_version() -> + highest_protocol_version(supported_protocol_versions()). + +lowest_protocol_version() -> + lowest_protocol_version(supported_protocol_versions()). + +sufficient_tlsv1_2_crypto_support() -> + CryptoSupport = crypto:supports(), + proplists:get_bool(sha256, proplists:get_value(hashs, CryptoSupport)). + -decode_cipher_text(#ssl_tls{type = Type, version = Version, - fragment = CipherFragment} = CipherText, - #{current_read := - #{compression_state := CompressionS0, - sequence_number := Seq, - security_parameters := - #security_parameters{compression_algorithm = CompAlg} - } = ReadState0} = ConnnectionStates0, PaddingCheck) -> - case ssl_record:decipher(Version, CipherFragment, ReadState0, PaddingCheck) of - {PlainFragment, Mac, ReadState1} -> - MacHash = ssl_cipher:calc_mac_hash(Type, Version, PlainFragment, ReadState1), - case ssl_record:is_correct_mac(Mac, MacHash) of - true -> - {Plain, CompressionS1} = ssl_record:uncompress(CompAlg, - PlainFragment, CompressionS0), - ConnnectionStates = ConnnectionStates0#{ - current_read => ReadState1#{ - sequence_number => Seq + 1, - compression_state => CompressionS1}}, - {CipherText#ssl_tls{fragment = Plain}, ConnnectionStates}; - false -> - ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) - end; - #alert{} = Alert -> - Alert - end. |