From f1db2eb29768eca2d7affdfd95753b477df05beb Mon Sep 17 00:00:00 2001 From: Ingela Anderton Andin Date: Fri, 15 Apr 2016 11:02:02 +0200 Subject: ssl: Remove use of crypto:rand_bytes/1 ssl already used crypto:strong_rand_bytes/1 for most operations as its use cases are mostly cryptographical. Now crypto:strong_rand_bytes/1 will be used everywhere. However crypto:rand_bytes/1 was used as fallback if crypto:strong_rand_bytes/1 throws low_entropy, this will no longer be the case. This is a potential incompatibility. The fallback was introduced a long time ago for interoperability reasons. Now days this should not be a problem, and if it is, the security compromise is not acceptable anyway. --- lib/ssl/src/ssl.erl | 18 +----------------- lib/ssl/src/ssl_cipher.erl | 22 +++++++++++++++++----- lib/ssl/src/ssl_connection.erl | 4 ++-- lib/ssl/src/ssl_manager.erl | 2 +- lib/ssl/src/ssl_record.erl | 2 +- lib/ssl/test/ssl_basic_SUITE.erl | 2 +- lib/ssl/test/ssl_dist_SUITE.erl | 2 +- lib/ssl/test/ssl_test_lib.erl | 2 +- 8 files changed, 25 insertions(+), 29 deletions(-) diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl index 4bcd6ddb0e..61afdce93c 100644 --- a/lib/ssl/src/ssl.erl +++ b/lib/ssl/src/ssl.erl @@ -42,7 +42,7 @@ renegotiate/1, prf/5, negotiated_protocol/1, negotiated_next_protocol/1, connection_information/1, connection_information/2]). %% Misc --export([random_bytes/1, handle_options/2]). +-export([handle_options/2]). -deprecated({negotiated_next_protocol, 1, next_major_release}). -deprecated({connection_info, 1, next_major_release}). @@ -581,22 +581,6 @@ format_error(Error) -> Other end. -%%-------------------------------------------------------------------- --spec random_bytes(integer()) -> binary(). - -%% -%% Description: Generates cryptographically secure random sequence if possible -%% fallbacks on pseudo random function -%%-------------------------------------------------------------------- -random_bytes(N) -> - try crypto:strong_rand_bytes(N) of - RandBytes -> - RandBytes - catch - error:low_entropy -> - crypto:rand_bytes(N) - end. - %%%-------------------------------------------------------------- %%% Internal functions %%%-------------------------------------------------------------------- diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl index e66f253a70..f58533b764 100644 --- a/lib/ssl/src/ssl_cipher.erl +++ b/lib/ssl/src/ssl_cipher.erl @@ -1,4 +1,4 @@ -%% +% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2007-2016. All Rights Reserved. @@ -39,7 +39,8 @@ suite/1, suites/1, all_suites/1, ec_keyed_suites/0, anonymous_suites/1, psk_suites/1, srp_suites/0, rc4_suites/1, des_suites/1, openssl_suite/1, openssl_suite_name/1, filter/2, filter_suites/1, - hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2, is_fallback/1]). + hash_algorithm/1, sign_algorithm/1, is_acceptable_hash/2, is_fallback/1, + random_bytes/1]). -export_type([cipher_suite/0, erl_cipher_suite/0, openssl_cipher_suite/0, @@ -49,7 +50,8 @@ | aes_128_cbc | aes_256_cbc | aes_128_gcm | aes_256_gcm | chacha20_poly1305. -type hash() :: null | sha | md5 | sha224 | sha256 | sha384 | sha512. -type sign_algo() :: rsa | dsa | ecdsa. --type key_algo() :: null | rsa | dhe_rsa | dhe_dss | ecdhe_ecdsa| ecdh_ecdsa | ecdh_rsa| srp_rsa| srp_dss | psk | dhe_psk | rsa_psk | dh_anon | ecdh_anon | srp_anon. +-type key_algo() :: null | rsa | dhe_rsa | dhe_dss | ecdhe_ecdsa| ecdh_ecdsa | ecdh_rsa| srp_rsa| srp_dss | + psk | dhe_psk | rsa_psk | dh_anon | ecdh_anon | srp_anon. -type erl_cipher_suite() :: {key_algo(), cipher(), hash()} % Pre TLS 1.2 %% TLS 1.2, internally PRE TLS 1.2 will use default_prf | {key_algo(), cipher(), hash(), hash() | default_prf}. @@ -102,7 +104,7 @@ cipher_init(?RC4, IV, Key) -> State = crypto:stream_init(rc4, Key), #cipher_state{iv = IV, key = Key, state = State}; cipher_init(?AES_GCM, IV, Key) -> - <> = ssl:random_bytes(8), + <> = random_bytes(8), #cipher_state{iv = IV, key = Key, nonce = Nonce}; cipher_init(_BCA, IV, Key) -> #cipher_state{iv = IV, key = Key}. @@ -1472,6 +1474,16 @@ is_acceptable_prf(Prf, Algos) -> is_fallback(CipherSuites)-> lists:member(?TLS_FALLBACK_SCSV, CipherSuites). + +%%-------------------------------------------------------------------- +-spec random_bytes(integer()) -> binary(). + +%% +%% Description: Generates cryptographically secure random sequence +%%-------------------------------------------------------------------- +random_bytes(N) -> + crypto:strong_rand_bytes(N). + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- @@ -1712,7 +1724,7 @@ get_padding_aux(BlockSize, PadLength) -> random_iv(IV) -> IVSz = byte_size(IV), - ssl:random_bytes(IVSz). + random_bytes(IVSz). next_iv(Bin, IV) -> BinSz = byte_size(Bin), diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl index 1568e8559f..0073e86e26 100644 --- a/lib/ssl/src/ssl_connection.erl +++ b/lib/ssl/src/ssl_connection.erl @@ -502,7 +502,7 @@ certify(#server_hello_done{}, role = client, key_algorithm = Alg} = State0, Connection) when Alg == rsa_psk -> - Rand = ssl:random_bytes(?NUM_OF_PREMASTERSECRET_BYTES-2), + Rand = ssl_cipher:random_bytes(?NUM_OF_PREMASTERSECRET_BYTES-2), RSAPremasterSecret = <>, case ssl_handshake:premaster_secret({Alg, PSKIdentity}, PSKLookup, RSAPremasterSecret) of #alert{} = Alert -> @@ -1885,7 +1885,7 @@ handle_resumed_session(SessId, #state{connection_states = ConnectionStates0, end. make_premaster_secret({MajVer, MinVer}, rsa) -> - Rand = ssl:random_bytes(?NUM_OF_PREMASTERSECRET_BYTES-2), + Rand = ssl_cipher:random_bytes(?NUM_OF_PREMASTERSECRET_BYTES-2), <>; make_premaster_secret(_, _) -> undefined. diff --git a/lib/ssl/src/ssl_manager.erl b/lib/ssl/src/ssl_manager.erl index e273581de9..2349158b11 100644 --- a/lib/ssl/src/ssl_manager.erl +++ b/lib/ssl/src/ssl_manager.erl @@ -551,7 +551,7 @@ last_delay_timer({_,_}, TRef, {_, LastClient}) -> new_id(_, 0, _, _) -> <<>>; new_id(Port, Tries, Cache, CacheCb) -> - Id = crypto:rand_bytes(?NUM_OF_SESSION_ID_BYTES), + Id = ssl_cipher:random_bytes(?NUM_OF_SESSION_ID_BYTES), case CacheCb:lookup(Cache, {Port, Id}) of undefined -> Now = erlang:monotonic_time(), diff --git a/lib/ssl/src/ssl_record.erl b/lib/ssl/src/ssl_record.erl index ecff950668..866bfcef7e 100644 --- a/lib/ssl/src/ssl_record.erl +++ b/lib/ssl/src/ssl_record.erl @@ -460,7 +460,7 @@ empty_security_params(ConnectionEnd = ?SERVER) -> random() -> Secs_since_1970 = calendar:datetime_to_gregorian_seconds( calendar:universal_time()) - 62167219200, - Random_28_bytes = crypto:rand_bytes(28), + Random_28_bytes = ssl_cipher:random_bytes(28), <>. dtls_next_epoch(#connection_state{epoch = undefined}) -> %% SSL/TLS diff --git a/lib/ssl/test/ssl_basic_SUITE.erl b/lib/ssl/test/ssl_basic_SUITE.erl index 50313e6a22..829ab126ec 100644 --- a/lib/ssl/test/ssl_basic_SUITE.erl +++ b/lib/ssl/test/ssl_basic_SUITE.erl @@ -1555,7 +1555,7 @@ tcp_connect_big(Config) when is_list(Config) -> {_, ServerNode, Hostname} = ssl_test_lib:run_where(Config), TcpOpts = [binary, {reuseaddr, true}], - Rand = crypto:rand_bytes(?MAX_CIPHER_TEXT_LENGTH+1), + Rand = crypto:strong_rand_bytes(?MAX_CIPHER_TEXT_LENGTH+1), Server = ssl_test_lib:start_upgrade_server_error([{node, ServerNode}, {port, 0}, {from, self()}, {timeout, 5000}, diff --git a/lib/ssl/test/ssl_dist_SUITE.erl b/lib/ssl/test/ssl_dist_SUITE.erl index bd0ddde090..e7cbfa63f4 100644 --- a/lib/ssl/test/ssl_dist_SUITE.erl +++ b/lib/ssl/test/ssl_dist_SUITE.erl @@ -194,7 +194,7 @@ payload(Config) when is_list(Config) -> ok = apply_on_ssl_node( NH2, fun () -> - Msg = crypto:rand_bytes(100000), + Msg = crypto:strong_rand_bytes(100000), SslPid ! {self(), Msg}, receive {SslPid, Msg} -> diff --git a/lib/ssl/test/ssl_test_lib.erl b/lib/ssl/test/ssl_test_lib.erl index 2cd23eb3b8..7e6562fb37 100644 --- a/lib/ssl/test/ssl_test_lib.erl +++ b/lib/ssl/test/ssl_test_lib.erl @@ -349,7 +349,7 @@ wait_for_result(Pid, Msg) -> user_lookup(psk, _Identity, UserState) -> {ok, UserState}; user_lookup(srp, Username, _UserState) -> - Salt = ssl:random_bytes(16), + Salt = ssl_cipher:random_bytes(16), UserPassHash = crypto:hash(sha, [Salt, crypto:hash(sha, [Username, <<$:>>, <<"secret">>])]), {ok, {srp_1024, Salt, UserPassHash}}. -- cgit v1.2.3