diff options
Diffstat (limited to 'lib/ssl/src/ssl_cipher.erl')
| -rw-r--r-- | lib/ssl/src/ssl_cipher.erl | 53 |
1 files changed, 29 insertions, 24 deletions
diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl index 72467ea2a0..bec0055353 100644 --- a/lib/ssl/src/ssl_cipher.erl +++ b/lib/ssl/src/ssl_cipher.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2007-2014. All Rights Reserved. +%% Copyright Ericsson AB 2007-2015. 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 @@ -33,11 +33,10 @@ -include_lib("public_key/include/public_key.hrl"). -export([security_parameters/2, security_parameters/3, suite_definition/1, - decipher/5, cipher/5, - suite/1, suites/1, all_suites/1, + decipher/6, cipher/5, suite/1, suites/1, all_suites/1, ec_keyed_suites/0, anonymous_suites/0, psk_suites/1, srp_suites/0, openssl_suite/1, openssl_suite_name/1, filter/2, filter_suites/1, - hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2]). + hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2, is_fallback/1]). -export_type([cipher_suite/0, erl_cipher_suite/0, openssl_cipher_suite/0, @@ -143,17 +142,18 @@ block_cipher(Fun, BlockSz, #cipher_state{key=Key, iv=IV} = CS0, {T, CS0#cipher_state{iv=NextIV}}. %%-------------------------------------------------------------------- --spec decipher(cipher_enum(), integer(), #cipher_state{}, binary(), ssl_record:ssl_version()) -> +-spec decipher(cipher_enum(), integer(), #cipher_state{}, binary(), + ssl_record:ssl_version(), boolean()) -> {binary(), binary(), #cipher_state{}} | #alert{}. %% %% Description: Decrypts the data and the MAC using cipher described %% by cipher_enum() and updating the cipher state. %%------------------------------------------------------------------- -decipher(?NULL, _HashSz, CipherState, Fragment, _) -> +decipher(?NULL, _HashSz, CipherState, Fragment, _, _) -> {Fragment, <<>>, CipherState}; -decipher(?RC4, HashSz, CipherState, Fragment, _) -> +decipher(?RC4, HashSz, CipherState, Fragment, _, _) -> State0 = case CipherState#cipher_state.state of - undefined -> crypto:stream_init(rc4, CipherState#cipher_state.key); + undefined -> crypto:stream_init(rc4, CipherState#cipher_state.key); S -> S end, try crypto:stream_decrypt(State0, Fragment) of @@ -171,23 +171,23 @@ decipher(?RC4, HashSz, CipherState, Fragment, _) -> ?ALERT_REC(?FATAL, ?BAD_RECORD_MAC) end; -decipher(?DES, HashSz, CipherState, Fragment, Version) -> +decipher(?DES, HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(Key, IV, T) -> crypto:block_decrypt(des_cbc, Key, IV, T) - end, CipherState, HashSz, Fragment, Version); -decipher(?'3DES', HashSz, CipherState, Fragment, Version) -> + end, CipherState, HashSz, Fragment, Version, PaddingCheck); +decipher(?'3DES', HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(<<K1:8/binary, K2:8/binary, K3:8/binary>>, IV, T) -> crypto:block_decrypt(des3_cbc, [K1, K2, K3], IV, T) - end, CipherState, HashSz, Fragment, Version); -decipher(?AES, HashSz, CipherState, Fragment, Version) -> + end, CipherState, HashSz, Fragment, Version, PaddingCheck); +decipher(?AES, HashSz, CipherState, Fragment, Version, PaddingCheck) -> block_decipher(fun(Key, IV, T) when byte_size(Key) =:= 16 -> crypto:block_decrypt(aes_cbc128, Key, IV, T); (Key, IV, T) when byte_size(Key) =:= 32 -> crypto:block_decrypt(aes_cbc256, Key, IV, T) - end, CipherState, HashSz, Fragment, Version). + end, CipherState, HashSz, Fragment, Version, PaddingCheck). block_decipher(Fun, #cipher_state{key=Key, iv=IV} = CipherState0, - HashSz, Fragment, Version) -> + HashSz, Fragment, Version, PaddingCheck) -> try Text = Fun(Key, IV, Fragment), NextIV = next_iv(Fragment, IV), @@ -195,7 +195,7 @@ block_decipher(Fun, #cipher_state{key=Key, iv=IV} = CipherState0, Content = GBC#generic_block_cipher.content, Mac = GBC#generic_block_cipher.mac, CipherState1 = CipherState0#cipher_state{iv=GBC#generic_block_cipher.next_iv}, - case is_correct_padding(GBC, Version) of + case is_correct_padding(GBC, Version, PaddingCheck) of true -> {Content, Mac, CipherState1}; false -> @@ -1108,6 +1108,9 @@ is_acceptable_prf(default_prf, _) -> is_acceptable_prf(Prf, Algos) -> proplists:get_bool(Prf, Algos). +is_fallback(CipherSuites)-> + lists:member(?TLS_FALLBACK_SCSV, CipherSuites). + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- @@ -1288,16 +1291,18 @@ generic_stream_cipher_from_bin(T, HashSz) -> #generic_stream_cipher{content=Content, mac=Mac}. -%% For interoperability reasons we do not check the padding content in -%% SSL 3.0 and TLS 1.0 as it is not strictly required and breaks -%% interopability with for instance Google. is_correct_padding(#generic_block_cipher{padding_length = Len, - padding = Padding}, {3, N}) - when N == 0; N == 1 -> - Len == byte_size(Padding); -%% Padding must be check in TLS 1.1 and after + padding = Padding}, {3, 0}, _) -> + Len == byte_size(Padding); %% Only length check is done in SSL 3.0 spec +%% For interoperability reasons it is possible to disable +%% the padding check when using TLS 1.0, as it is not strictly required +%% in the spec (only recommended), howerver this makes TLS 1.0 vunrable to the Poodle attack +%% so by default this clause will not match +is_correct_padding(GenBlockCipher, {3, 1}, false) -> + is_correct_padding(GenBlockCipher, {3, 0}, false); +%% Padding must be checked in TLS 1.1 and after is_correct_padding(#generic_block_cipher{padding_length = Len, - padding = Padding}, _) -> + padding = Padding}, _, _) -> Len == byte_size(Padding) andalso list_to_binary(lists:duplicate(Len, Len)) == Padding. |