diff options
Diffstat (limited to 'lib/ssl')
| -rw-r--r-- | lib/ssl/src/ssl_connection.erl | 33 | ||||
| -rw-r--r-- | lib/ssl/test/ssl_basic_SUITE.erl | 49 |
2 files changed, 75 insertions, 7 deletions
diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl index 0c44d3ae90..dda0c27d0c 100644 --- a/lib/ssl/src/ssl_connection.erl +++ b/lib/ssl/src/ssl_connection.erl @@ -90,12 +90,14 @@ renegotiation, % {boolean(), From | internal | peer} recv_during_renegotiation, %boolean() send_queue, % queue() - terminated = false % + terminated = false, % + allow_renegotiate = true }). -define(DEFAULT_DIFFIE_HELLMAN_PARAMS, - #'DHParameter'{prime = ?DEFAULT_DIFFIE_HELLMAN_PRIME, + #'DHParameter'{prime = ?DEFAULT_DIFFIE_HELLMAN_PRIME, base = ?DEFAULT_DIFFIE_HELLMAN_GENERATOR}). +-define(WAIT_TO_ALLOW_RENEGOTIATION, 12000). -type state_name() :: hello | abbreviated | certify | cipher | connection. -type gen_fsm_state_return() :: {next_state, state_name(), #state{}} | @@ -706,9 +708,25 @@ connection(#hello_request{}, #state{host = Host, port = Port, ConnectionStates1, tls_handshake_hashes = Hashes1}), next_state(hello, Record, State); -connection(#client_hello{} = Hello, #state{role = server} = State) -> - hello(Hello, State); - +connection(#client_hello{} = Hello, #state{role = server, allow_renegotiate = true} = State) -> + %% Mitigate Computational DoS attack http://www.educatedguesswork.org/2011/10/ssltls_and_computational_dos.html + %% http://www.thc.org/thc-ssl-dos/ Rather than disabling client initiated renegotiation + %% we will disallow many client initiated renegotiations immediately after each other. + erlang:send_after(?WAIT_TO_ALLOW_RENEGOTIATION, self(), allow_renegotiate), + hello(Hello, State#state{allow_renegotiate = false}); + +connection(#client_hello{}, #state{role = server, allow_renegotiate = false, + connection_states = ConnectionStates0, + socket = Socket, transport_cb = Transport, + negotiated_version = Version} = State0) -> + Alert = ?ALERT_REC(?WARNING, ?NO_RENEGOTIATION), + {BinMsg, ConnectionStates} = + encode_alert(Alert, Version, ConnectionStates0), + Transport:send(Socket, BinMsg), + {Record, State} = next_record(State0#state{connection_states = + ConnectionStates}), + next_state(connection, Record, State); + connection(timeout, State) -> {next_state, connection, State, hibernate}; @@ -983,6 +1001,9 @@ handle_info({'DOWN', MonitorRef, _, _, _}, _, State = #state{user_application={MonitorRef,_Pid}}) -> {stop, normal, State}; +handle_info(allow_renegotiate, StateName, State) -> + {next_state, StateName, State#state{allow_renegotiate = true}, get_timeout(State)}; + handle_info(Msg, StateName, State) -> Report = io_lib:format("SSL: Got unexpected info: ~p ~n", [Msg]), error_logger:info_report(Report), @@ -2298,7 +2319,7 @@ renegotiate(#state{role = server, {Record, State} = next_record(State0#state{connection_states = ConnectionStates, tls_handshake_hashes = Hs0}), - next_state(hello, Record, State). + next_state(hello, Record, State#state{allow_renegotiate = true}). notify_senders(SendQueue) -> lists:foreach(fun({From, _}) -> diff --git a/lib/ssl/test/ssl_basic_SUITE.erl b/lib/ssl/test/ssl_basic_SUITE.erl index d9cb8002ed..fc8aafa426 100644 --- a/lib/ssl/test/ssl_basic_SUITE.erl +++ b/lib/ssl/test/ssl_basic_SUITE.erl @@ -36,6 +36,7 @@ -define(LONG_TIMEOUT, 600000). -define(EXPIRE, 10). -define(SLEEP, 500). +-define(RENEGOTIATION_DISABLE_TIME, 12000). %% Test server callback functions %%-------------------------------------------------------------------- @@ -256,7 +257,7 @@ all() -> %%different_ca_peer_sign, no_reuses_session_server_restart_new_cert, no_reuses_session_server_restart_new_cert_file, reuseaddr, - hibernate, connect_twice + hibernate, connect_twice, renegotiate_dos_mitigate ]. groups() -> @@ -3647,7 +3648,40 @@ connect_twice(Config) when is_list(Config) -> ssl_test_lib:close(Client), ssl_test_lib:close(Client1). +%%-------------------------------------------------------------------- +renegotiate_dos_mitigate(doc) -> + ["Mitigate DOS computational attack by not allowing client to renegotiate many times in a row", + "immediately after each other"]; + +renegotiate_dos_mitigate(suite) -> + []; + +renegotiate_dos_mitigate(Config) when is_list(Config) -> + ServerOpts = ?config(server_opts, Config), + ClientOpts = ?config(client_opts, Config), + + {ClientNode, ServerNode, Hostname} = ssl_test_lib:run_where(Config), + + Server = + ssl_test_lib:start_server([{node, ServerNode}, {port, 0}, + {from, self()}, + {mfa, {?MODULE, send_recv_result_active, []}}, + {options, [ServerOpts]}]), + Port = ssl_test_lib:inet_port(Server), + + Client = ssl_test_lib:start_client([{node, ClientNode}, {port, Port}, + {host, Hostname}, + {from, self()}, + {mfa, {?MODULE, + renegotiate_immediately, []}}, + {options, ClientOpts}]), + + ssl_test_lib:check_result(Client, ok, Server, ok), + ssl_test_lib:close(Server), + ssl_test_lib:close(Client). + + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- @@ -3690,6 +3724,19 @@ renegotiate_reuse_session(Socket, Data) -> test_server:sleep(?SLEEP), renegotiate(Socket, Data). +renegotiate_immediately(Socket) -> + receive + {ssl, Socket, "Hello world"} -> + ok + end, + ok = ssl:renegotiate(Socket), + {error, renegotiation_rejected} = ssl:renegotiate(Socket), + test_server:sleep(?RENEGOTIATION_DISABLE_TIME +1), + ok = ssl:renegotiate(Socket), + test_server:format("Renegotiated again"), + ssl:send(Socket, "Hello world"), + ok. + new_config(PrivDir, ServerOpts0) -> CaCertFile = proplists:get_value(cacertfile, ServerOpts0), CertFile = proplists:get_value(certfile, ServerOpts0), |