- tor-commits - lists.torproject.org

[tor/master] Revert "Make pending libevent actions cancelable"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 135a5102a3e5422a1c9c8ad28f58888eea4a2545 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Make pending libevent actions cancelable" This reverts commit aba25a6939a5907d40dbcff7433a8c130ffd12ad. --- src/common/compat_libevent.c | 24 +++++++----------------- src/common/compat_libevent.h | 8 +++----- src/common/tortls.c | 13 ++++++++++--- src/or/connection_or.c | 25 ++++--------------------- src/or/or.h | 2 -- 5 files changed, 24 insertions(+), 48 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index 67f4659..3a754be 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -558,17 +558,17 @@ tor_check_libevent_header_compatibility(void) #endif } -struct tor_libevent_action_t { +typedef struct runnable_t { struct event *ev; void (*cb)(void *arg); void *arg; -}; +} runnable_t; /** Callback for tor_run_in_libevent_loop */ static void run_runnable_cb(evutil_socket_t s, short what, void *arg) { - tor_libevent_action_t *r = arg; + runnable_t *r = arg; void (*cb)(void *) = r->cb; void *cb_arg = r->arg; (void)what; @@ -584,32 +584,22 @@ run_runnable_cb(evutil_socket_t s, short what, void *arg) * deep inside a no-reentrant code and there's some function you want to call * without worrying about whether it might cause reeentrant invocation. */ -tor_libevent_action_t * +int tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg) { - tor_libevent_action_t *r = tor_malloc(sizeof(tor_libevent_action_t)); + runnable_t *r = tor_malloc(sizeof(runnable_t)); r->cb = cb; r->arg = arg; r->ev = tor_event_new(tor_libevent_get_base(), -1, EV_TIMEOUT, run_runnable_cb, r); if (!r->ev) { tor_free(r); - return NULL; + return -1; } /* Make the event active immediately. */ event_active(r->ev, EV_TIMEOUT, 1); - return r; -} - -/** - * Cancel action without running it. - */ -void -tor_cancel_libevent_action(tor_libevent_action_t *action) -{ - tor_event_free(action->ev); - tor_free(action); + return 0; } /* diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index 4076cc0..3f916d1 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -44,12 +44,10 @@ void tor_event_free(struct event *ev); #define tor_evdns_add_server_port evdns_add_server_port #endif -typedef struct tor_libevent_action_t tor_libevent_action_t; -tor_libevent_action_t *tor_run_in_libevent_loop(void (*cb)(void *arg), - void *arg); -void tor_cancel_libevent_action(tor_libevent_action_t *action); - typedef struct periodic_timer_t periodic_timer_t; + +int tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg); + periodic_timer_t *periodic_timer_new(struct event_base *base, const struct timeval *tv, void (*cb)(periodic_timer_t *timer, void *data), diff --git a/src/common/tortls.c b/src/common/tortls.c index a6947c8..b4d81de 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1339,9 +1339,16 @@ tor_tls_got_client_hello(tor_tls_t *tls) tls->excess_renegotiations_callback) { /* We got more than one renegotiation requests. The Tor protocol needs just one renegotiation; more than that probably means - They are trying to DoS us and we have to stop them. */ - - tls->excess_renegotiations_callback(tls->callback_arg); + They are trying to DoS us and we have to stop them. We can't + close their connection from in here since it's an OpenSSL + callback, so we set a libevent timer that triggers in the next + event loop and closes the connection. */ + + if (tor_run_in_libevent_loop(tls->excess_renegotiations_callback, + tls->callback_arg) < 0) { + log_warn(LD_GENERAL, "Didn't manage to set a renegotiation " + "limiting callback."); + } } /* Now check the cipher list. */ diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 6082be4..82297c3 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -492,9 +492,6 @@ connection_or_about_to_close(or_connection_t *or_conn) time_t now = time(NULL); connection_t *conn = TO_CONN(or_conn); - if (or_conn->pending_action) - tor_cancel_libevent_action(or_conn->pending_action); - /* Remember why we're closing this connection. */ if (conn->state != OR_CONN_STATE_OPEN) { /* Inform any pending (not attached) circs that they should @@ -1159,34 +1156,20 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) } } -/*DOCDOC*/ +/** Invoked on the server side using a timer from inside + * tor_tls_got_client_hello() when the server receives excess + * renegotiation attempts; probably indicating a DoS. */ static void -close_connection_libevent_cb(void *_conn) +connection_or_close_connection_cb(void *_conn) { or_connection_t *or_conn = _conn; connection_t *conn = TO_CONN(or_conn); - or_conn->pending_action = NULL; - connection_stop_reading(conn); if (!conn->marked_for_close) connection_mark_for_close(conn); } -/* DOCDOC */ -static void -connection_or_close_connection_cb(void *_conn) -{ - /* We can't close their connection from in here since it's an OpenSSL - callback, so we set a libevent event that triggers in the next event - loop and closes the connection. */ - or_connection_t *or_conn = _conn; - if (or_conn->_base.marked_for_close || or_conn->pending_action) - return; - or_conn->pending_action = - tor_run_in_libevent_loop(close_connection_libevent_cb, or_conn); -} - /** Move forward with the tls handshake. If it finishes, hand * conn to connection_tls_finish_handshake(). * diff --git a/src/or/or.h b/src/or/or.h index eb9f060..6ff02ee 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -1276,8 +1276,6 @@ typedef struct or_connection_t { unsigned active_circuit_pqueue_last_recalibrated; struct or_connection_t *next_with_same_id; /**< Next connection with same * identity digest as this one. */ - - tor_libevent_action_t *pending_action; } or_connection_t; /** Subtype of connection_t for an "edge connection" -- that is, an entry (ap)

1 0

[tor/master] Revert "indent; add comment"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 75134c6c86e54c10fd9e11c4345aadcdabc0f8fb Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "indent; add comment" This reverts commit 40a87c4c08be0cdd87a3df283f285b3c2a0c8445. --- src/common/tortls.c | 14 ++++++-------- 1 files changed, 6 insertions(+), 8 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index b4d81de..9ac5c34 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -585,8 +585,6 @@ tor_tls_create_certificate(crypto_pk_env_t *rsa, const char *cname_sign, unsigned int cert_lifetime) { - /* OpenSSL generates self-signed certificates with random 64-bit serial - * numbers, so let's do that too. */ #define SERIAL_NUMBER_SIZE 8 time_t start_time, end_time; @@ -614,12 +612,12 @@ tor_tls_create_certificate(crypto_pk_env_t *rsa, goto error; { /* our serial number is 8 random bytes. */ - if (crypto_rand((char *)serial_tmp, sizeof(serial_tmp)) < 0) - goto error; - if (!(serial_number = BN_bin2bn(serial_tmp, sizeof(serial_tmp), NULL))) - goto error; - if (!(BN_to_ASN1_INTEGER(serial_number, X509_get_serialNumber(x509)))) - goto error; + if (crypto_rand((char *)serial_tmp, sizeof(serial_tmp)) < 0) + goto error; + if (!(serial_number = BN_bin2bn(serial_tmp, sizeof(serial_tmp), NULL))) + goto error; + if (!(BN_to_ASN1_INTEGER(serial_number, X509_get_serialNumber(x509)))) + goto error; } if (!(name = tor_x509_name_new(cname)))

1 0

[tor/master] Revert "Don't schedule excess_renegotiations_callback unless it's set"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit acc1806eb85b9bb3b6afdb4b6b489b5e23b97d94 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Don't schedule excess_renegotiations_callback unless it's set" This reverts commit 617617e21a2d30a86cea9c8f7043333078f2e8f8. --- src/common/tortls.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index 9ac5c34..9a77bab 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1333,8 +1333,7 @@ tor_tls_got_client_hello(tor_tls_t *tls) } tls->got_renegotiate = 1; - } else if (tls->server_handshake_count > 2 && - tls->excess_renegotiations_callback) { + } else if (tls->server_handshake_count > 2) { /* We got more than one renegotiation requests. The Tor protocol needs just one renegotiation; more than that probably means They are trying to DoS us and we have to stop them. We can't

1 0

[tor/master] Revert "use event_free() wrapper; fix bug 4582"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit e83e720c8bf1f97c3df2ed272296f6dbcc4b8c24 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "use event_free() wrapper; fix bug 4582" This reverts commit 9a88c0cd32df53116a6bbb6b961650943755061c. --- src/common/compat_libevent.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index 3a754be..c3a4746 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -573,7 +573,7 @@ run_runnable_cb(evutil_socket_t s, short what, void *arg) void *cb_arg = r->arg; (void)what; (void)s; - tor_event_free(r->ev); + event_free(r->ev); tor_free(r); cb(cb_arg);

1 0

[tor/master] Revert "Fix some wide lines in tortls.c"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 17880e4c0a9670178d0722aea387c6885a28e69a Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Fix some wide lines in tortls.c" This reverts commit e8dde3aabd3e1292d381eb4269c6457548dca6b9. --- src/common/tortls.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index 9a77bab..4592514 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1343,8 +1343,7 @@ tor_tls_got_client_hello(tor_tls_t *tls) if (tor_run_in_libevent_loop(tls->excess_renegotiations_callback, tls->callback_arg) < 0) { - log_warn(LD_GENERAL, "Didn't manage to set a renegotiation " - "limiting callback."); + log_warn(LD_GENERAL, "Didn't manage to set a renegotiation limiting callback."); } } @@ -1399,6 +1398,7 @@ tor_tls_state_changed_callback(const SSL *ssl, int type, int val) tor_tls_got_client_hello(tls); } #endif + } /** Replace *ciphers with a new list of SSL ciphersuites: specifically, @@ -1666,8 +1666,8 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len) #ifdef V2_HANDSHAKE_SERVER if (tls->got_renegotiate) { if (tls->server_handshake_count != 2) { - log_warn(LD_BUG, "We did not notice renegotiation in a timely " - "fashion (%u)!", tls->server_handshake_count); + log_warn(LD_BUG, "We did not notice renegotiation in a timely fashion (%u)!", + tls->server_handshake_count); } /* Renegotiation happened! */

1 0

[tor/master] Revert "Avoid a double-mark in connection_or_close_connection_cb"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 3a17a1a62f242f3aa64891407d3d64aa040d6d02 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Avoid a double-mark in connection_or_close_connection_cb" This reverts commit 633071eb3bcf2c4106e93de28d727594bd23b1db. --- src/or/connection_or.c | 8 +++----- 1 files changed, 3 insertions(+), 5 deletions(-) diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 82297c3..44f559c 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -1162,12 +1162,10 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) static void connection_or_close_connection_cb(void *_conn) { - or_connection_t *or_conn = _conn; - connection_t *conn = TO_CONN(or_conn); + or_connection_t *conn = _conn; - connection_stop_reading(conn); - if (!conn->marked_for_close) - connection_mark_for_close(conn); + connection_stop_reading(TO_CONN(conn)); + connection_mark_for_close(TO_CONN(conn)); } /** Move forward with the tls handshake. If it finishes, hand

1 0

[tor/master] Revert "appease check-spaces"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 53f535aeb863204470379b2da4631770fa10b13f Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "appease check-spaces" This reverts commit f77f9bddb8bf0dd6e9c3e0d94269aa23f459a272. --- src/common/compat_libevent.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index b709b4a..fcc1193 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -243,8 +243,8 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg) * again. */ #if defined(MS_WINDOWS) && defined(USE_BUFFEREVENTS) if (torcfg->disable_iocp == 0) { - log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again " - "with IOCP disabled."); + log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again with " + "IOCP disabled."); } else #endif { @@ -254,6 +254,7 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg) torcfg->disable_iocp = 1; goto retry; } + } #else the_event_base = event_init();

1 0

[tor/master] Revert "Refactor tor_event_base_once to do what we actually want"
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit df1f72329acf5f555618a5309f2621e584c0d763 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Refactor tor_event_base_once to do what we actually want" This reverts commit 7920ea55b8d994268d2b07f27316b0f34d8f27e5. --- src/common/compat_libevent.c | 45 ++++------------------------------------- src/common/compat_libevent.h | 3 +- src/common/tortls.c | 10 +++++--- src/common/tortls.h | 2 +- src/common/util.c | 4 +- src/or/connection_or.c | 4 ++- 6 files changed, 19 insertions(+), 49 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index c3a4746..b709b4a 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -558,48 +558,13 @@ tor_check_libevent_header_compatibility(void) #endif } -typedef struct runnable_t { - struct event *ev; - void (*cb)(void *arg); - void *arg; -} runnable_t; - -/** Callback for tor_run_in_libevent_loop */ -static void -run_runnable_cb(evutil_socket_t s, short what, void *arg) -{ - runnable_t *r = arg; - void (*cb)(void *) = r->cb; - void *cb_arg = r->arg; - (void)what; - (void)s; - event_free(r->ev); - tor_free(r); - - cb(cb_arg); -} - -/** Cause cb(arg) to run later on this iteration of the libevent loop, or in - * the next iteration of the libevent loop. This is useful for when you're - * deep inside a no-reentrant code and there's some function you want to call - * without worrying about whether it might cause reeentrant invocation. - */ +/** Wrapper around libevent's event_base_once(). Sets a + * timeout-triggered event with no associated file descriptor. */ int -tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg) +tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), + void *arg, struct timeval *timer) { - runnable_t *r = tor_malloc(sizeof(runnable_t)); - r->cb = cb; - r->arg = arg; - r->ev = tor_event_new(tor_libevent_get_base(), -1, EV_TIMEOUT, - run_runnable_cb, r); - if (!r->ev) { - tor_free(r); - return -1; - } - /* Make the event active immediately. */ - event_active(r->ev, EV_TIMEOUT, 1); - - return 0; + return event_base_once(tor_libevent_get_base(), -1, EV_TIMEOUT, cb, arg, timer); } /* diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index 3f916d1..897eddb 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -46,7 +46,8 @@ void tor_event_free(struct event *ev); typedef struct periodic_timer_t periodic_timer_t; -int tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg); +int tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), + void *arg, struct timeval *timer); periodic_timer_t *periodic_timer_new(struct event_base *base, const struct timeval *tv, diff --git a/src/common/tortls.c b/src/common/tortls.c index 4592514..2ef2803 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -160,7 +160,7 @@ struct tor_tls_t { /** Callback to invoke whenever a client tries to renegotiate more than once. */ - void (*excess_renegotiations_callback)(void *); + void (*excess_renegotiations_callback)(evutil_socket_t, short, void *); /** Argument to pass to negotiated_callback. */ void *callback_arg; @@ -1341,8 +1341,10 @@ tor_tls_got_client_hello(tor_tls_t *tls) callback, so we set a libevent timer that triggers in the next event loop and closes the connection. */ - if (tor_run_in_libevent_loop(tls->excess_renegotiations_callback, - tls->callback_arg) < 0) { + struct timeval zero_seconds_timer = {0,0}; + + if (tor_event_base_once(tls->excess_renegotiations_callback, + tls->callback_arg, &zero_seconds_timer) < 0) { log_warn(LD_GENERAL, "Didn't manage to set a renegotiation limiting callback."); } } @@ -1570,7 +1572,7 @@ tor_tls_set_logged_address(tor_tls_t *tls, const char *address) void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(void *), + void (*cb2)(evutil_socket_t, short, void *), void *arg) { tls->negotiated_callback = cb; diff --git a/src/common/tortls.h b/src/common/tortls.h index 9f86e37..5874881 100644 --- a/src/common/tortls.h +++ b/src/common/tortls.h @@ -63,7 +63,7 @@ tor_tls_t *tor_tls_new(int sock, int is_server); void tor_tls_set_logged_address(tor_tls_t *tls, const char *address); void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(void *), + void (*cb2)(evutil_socket_t, short, void *), void *arg); int tor_tls_is_server(tor_tls_t *tls); void tor_tls_free(tor_tls_t *tls); diff --git a/src/common/util.c b/src/common/util.c index 6d488d9..a59cab0 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -3661,8 +3661,8 @@ tor_get_exit_code(const process_handle_t *process_handle, /* Process has not exited */ return PROCESS_EXIT_RUNNING; } else if (retval != process_handle->pid) { - log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", - process_handle->pid, strerror(errno)); + log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", process_handle->pid, + strerror(errno)); return PROCESS_EXIT_ERROR; } diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 44f559c..ff696f8 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -1160,9 +1160,11 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) * tor_tls_got_client_hello() when the server receives excess * renegotiation attempts; probably indicating a DoS. */ static void -connection_or_close_connection_cb(void *_conn) +connection_or_close_connection_cb(evutil_socket_t fd, short what, void *_conn) { or_connection_t *conn = _conn; + (void) what; + (void) fd; connection_stop_reading(TO_CONN(conn)); connection_mark_for_close(TO_CONN(conn));

1 0

[tor/master] Revert "Use callback-driven approach to block renegotiations."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 616b60cef39f78d8a6ebb984096ff0ec09a3021c Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Use callback-driven approach to block renegotiations." This reverts commit 406ae1ba5ad529a4d0e710229dab6ed645d42b50. --- src/common/compat_libevent.c | 9 ------ src/common/compat_libevent.h | 3 -- src/common/tortls.c | 57 ++++++++++++++++++++--------------------- src/common/tortls.h | 4 +-- src/or/connection_or.c | 20 +------------- 5 files changed, 31 insertions(+), 62 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index fcc1193..7a28c9b 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -559,15 +559,6 @@ tor_check_libevent_header_compatibility(void) #endif } -/** Wrapper around libevent's event_base_once(). Sets a - * timeout-triggered event with no associated file descriptor. */ -int -tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), - void *arg, struct timeval *timer) -{ - return event_base_once(tor_libevent_get_base(), -1, EV_TIMEOUT, cb, arg, timer); -} - /* If possible, we're going to try to use Libevent's periodic timer support, since it does a pretty good job of making sure that periodic events get diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index 897eddb..0247297 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -46,9 +46,6 @@ void tor_event_free(struct event *ev); typedef struct periodic_timer_t periodic_timer_t; -int tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), - void *arg, struct timeval *timer); - periodic_timer_t *periodic_timer_new(struct event_base *base, const struct timeval *tv, void (*cb)(periodic_timer_t *timer, void *data), diff --git a/src/common/tortls.c b/src/common/tortls.c index 2ef2803..62d34f7 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -52,6 +52,7 @@ #include <event2/bufferevent_ssl.h> #include <event2/buffer.h> #include <event2/event.h> +#include "compat_libevent.h" #endif #define CRYPTO_PRIVATE /* to import prototypes from crypto.h */ @@ -63,7 +64,6 @@ #include "torlog.h" #include "container.h" #include <string.h> -#include "compat_libevent.h" /* Enable the "v2" TLS handshake. */ @@ -157,11 +157,6 @@ struct tor_tls_t { /** If set, a callback to invoke whenever the client tries to renegotiate * the handshake. */ void (*negotiated_callback)(tor_tls_t *tls, void *arg); - - /** Callback to invoke whenever a client tries to renegotiate more - than once. */ - void (*excess_renegotiations_callback)(evutil_socket_t, short, void *); - /** Argument to pass to negotiated_callback. */ void *callback_arg; }; @@ -1265,6 +1260,17 @@ tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime, return NULL; } +/** Return true if the tls object has completed more + * renegotiations than needed for the Tor protocol. */ +static INLINE int +tor_tls_got_excess_renegotiations(tor_tls_t *tls) +{ + /** The Tor v2 server handshake needs a single renegotiation after + the initial SSL handshake. This means that if we ever see more + than 2 handshakes, we raise the flag. */ + return (tls->server_handshake_count > 2) ? 1 : 0; +} + #ifdef V2_HANDSHAKE_SERVER /** Return true iff the cipher list suggested by the client for ssl is * a list that indicates that the client knows how to do the v2 TLS connection @@ -1333,20 +1339,6 @@ tor_tls_got_client_hello(tor_tls_t *tls) } tls->got_renegotiate = 1; - } else if (tls->server_handshake_count > 2) { - /* We got more than one renegotiation requests. The Tor protocol - needs just one renegotiation; more than that probably means - They are trying to DoS us and we have to stop them. We can't - close their connection from in here since it's an OpenSSL - callback, so we set a libevent timer that triggers in the next - event loop and closes the connection. */ - - struct timeval zero_seconds_timer = {0,0}; - - if (tor_event_base_once(tls->excess_renegotiations_callback, - tls->callback_arg, &zero_seconds_timer) < 0) { - log_warn(LD_GENERAL, "Didn't manage to set a renegotiation limiting callback."); - } } /* Now check the cipher list. */ @@ -1563,20 +1555,16 @@ tor_tls_set_logged_address(tor_tls_t *tls, const char *address) tls->address = tor_strdup(address); } -/** Set cb to be called with argument arg whenever - * tls next gets a client-side renegotiate in the middle of a - * read. Set cb2 to be called with argument arg whenever - * tls gets excess renegotiation requests. Do not invoke this - * function until after initial handshaking is done! +/** Set cb to be called with argument arg whenever tls + * next gets a client-side renegotiate in the middle of a read. Do not + * invoke this function until after initial handshaking is done! */ void -tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, +tor_tls_set_renegotiate_callback(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(evutil_socket_t, short, void *), void *arg) { tls->negotiated_callback = cb; - tls->excess_renegotiations_callback = cb2; tls->callback_arg = arg; tls->got_renegotiate = 0; SSL_set_info_callback(tls->ssl, tor_tls_state_changed_callback); @@ -1636,7 +1624,6 @@ tor_tls_free(tor_tls_t *tls) SSL_free(tls->ssl); tls->ssl = NULL; tls->negotiated_callback = NULL; - tls->excess_renegotiations_callback = NULL; if (tls->context) tor_tls_context_decref(tls->context); tor_free(tls->address); @@ -1665,6 +1652,12 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len) err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET); + if (tor_tls_got_excess_renegotiations(tls)) { + log_info(LD_NET, "Detected excess renegotiation from %s!", ADDR(tls)); + + return TOR_TLS_ERROR_MISC; + } + #ifdef V2_HANDSHAKE_SERVER if (tls->got_renegotiate) { if (tls->server_handshake_count != 2) { @@ -1719,6 +1712,12 @@ tor_tls_write(tor_tls_t *tls, const char *cp, size_t n) r = SSL_write(tls->ssl, cp, (int)n); err = tor_tls_get_error(tls, r, 0, "writing", LOG_INFO, LD_NET); + if (tor_tls_got_excess_renegotiations(tls)) { + log_info(LD_NET, "Detected excess renegotiation from %s!", ADDR(tls)); + + return TOR_TLS_ERROR_MISC; + } + if (err == TOR_TLS_DONE) { return r; } diff --git a/src/common/tortls.h b/src/common/tortls.h index 5874881..e558df7 100644 --- a/src/common/tortls.h +++ b/src/common/tortls.h @@ -13,7 +13,6 @@ #include "crypto.h" #include "compat.h" -#include "compat_libevent.h" /* Opaque structure to hold a TLS connection. */ typedef struct tor_tls_t tor_tls_t; @@ -61,9 +60,8 @@ int tor_tls_context_init(int is_public_server, unsigned int key_lifetime); tor_tls_t *tor_tls_new(int sock, int is_server); void tor_tls_set_logged_address(tor_tls_t *tls, const char *address); -void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, +void tor_tls_set_renegotiate_callback(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(evutil_socket_t, short, void *), void *arg); int tor_tls_is_server(tor_tls_t *tls); void tor_tls_free(tor_tls_t *tls); diff --git a/src/or/connection_or.c b/src/or/connection_or.c index ff696f8..992db9a 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -1156,20 +1156,6 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) } } -/** Invoked on the server side using a timer from inside - * tor_tls_got_client_hello() when the server receives excess - * renegotiation attempts; probably indicating a DoS. */ -static void -connection_or_close_connection_cb(evutil_socket_t fd, short what, void *_conn) -{ - or_connection_t *conn = _conn; - (void) what; - (void) fd; - - connection_stop_reading(TO_CONN(conn)); - connection_mark_for_close(TO_CONN(conn)); -} - /** Move forward with the tls handshake. If it finishes, hand * conn to connection_tls_finish_handshake(). * @@ -1216,9 +1202,8 @@ connection_tls_continue_handshake(or_connection_t *conn) /* v2/v3 handshake, but not a client. */ log_debug(LD_OR, "Done with initial SSL handshake (server-side). " "Expecting renegotiation or VERSIONS cell"); - tor_tls_set_renegotiate_callbacks(conn->tls, + tor_tls_set_renegotiate_callback(conn->tls, connection_or_tls_renegotiated_cb, - connection_or_close_connection_cb, conn); conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING; connection_stop_writing(TO_CONN(conn)); @@ -1280,9 +1265,8 @@ connection_or_handle_event_cb(struct bufferevent *bufev, short event, } else if (tor_tls_get_num_server_handshakes(conn->tls) == 1) { /* v2 or v3 handshake, as a server. Only got one handshake, so * wait for the next one. */ - tor_tls_set_renegotiate_callbacks(conn->tls, + tor_tls_set_renegotiate_callback(conn->tls, connection_or_tls_renegotiated_cb, - connection_or_close_connection_cb, conn); conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING; /* return 0; */

1 0

[tor/master] Revert "Also handle needless renegotiations in SSL_write()."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit fa74af0cfa834edbfe5d02ec22fe7c53699770a3 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Also handle needless renegotiations in SSL_write()." This reverts commit e2b3527106e0747f652e2f28fa087d9874e0e2ce. --- src/common/tortls.c | 32 ++++++++------------------------ 1 files changed, 8 insertions(+), 24 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index 65c26cc..ddb5ea1 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1260,17 +1260,6 @@ tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime, return NULL; } -/** Return true if the tls object has completed more - * renegotiations than needed for the Tor protocol. */ -static INLINE int -tor_tls_got_excess_renegotiations(tor_tls_t *tls) -{ - /** The Tor v2 server handshake needs a single renegotiation after - the initial SSL handshake. This means that if we ever see more - than 2 handshakes, we raise the flag. */ - return (tls->server_handshake_count > 2) ? 1 : 0; -} - #ifdef V2_HANDSHAKE_SERVER /** Return true iff the cipher list suggested by the client for ssl is * a list that indicates that the client knows how to do the v2 TLS connection @@ -1648,12 +1637,6 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len) err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET); - if (tor_tls_got_excess_renegotiations(tls)) { - log_info(LD_NET, "Detected excess renegotiation from %s!", ADDR(tls)); - - return TOR_TLS_ERROR_MISC; - } - #ifdef V2_HANDSHAKE_SERVER if (tls->got_renegotiate) { tor_assert(tls->server_handshake_count == 2); @@ -1666,6 +1649,14 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len) tls->got_renegotiate = 0; return r; + } else if (tls->server_handshake_count > 2) { + /* If we get more than 2 handshakes, it means that our peer is + trying to re-renegotiate. Return an error. */ + tor_assert(tls->server_handshake_count == 3); + + log_info(LD_NET, "Detected excess renegotiation from %s!", ADDR(tls)); + + return TOR_TLS_ERROR_MISC; } #endif @@ -1705,13 +1696,6 @@ tor_tls_write(tor_tls_t *tls, const char *cp, size_t n) } r = SSL_write(tls->ssl, cp, (int)n); err = tor_tls_get_error(tls, r, 0, "writing", LOG_INFO, LD_NET); - - if (tor_tls_got_excess_renegotiations(tls)) { - log_info(LD_NET, "Detected excess renegotiation from %s!", ADDR(tls)); - - return TOR_TLS_ERROR_MISC; - } - if (err == TOR_TLS_DONE) { return r; }

1 0