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[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; */

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[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

[tor/master] Revert "Fix issues pointed out by nickm."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 45c46129ed7a53844d6bed5ecda9d15dc8a676aa Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:20 2011 -0500 Revert "Fix issues pointed out by nickm." This reverts commit e097bffaed72af6b19f7293722021196bb94de1e. --- src/common/tortls.c | 26 ++++++++++---------------- 1 files changed, 10 insertions(+), 16 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index 62d34f7..65c26cc 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1323,21 +1323,17 @@ tor_tls_client_is_using_v2_ciphers(const SSL *ssl, const char *address) return 1; } -/** We got an SSL ClientHello message. This might mean that the - * client wants to initiate a renegotiation and appropriate actions - * must be taken. */ +/** We sent the ServerHello part of an SSL handshake. This might mean + * that we completed a renegotiation and appropriate actions must be + * taken. */ static void -tor_tls_got_client_hello(tor_tls_t *tls) +tor_tls_got_server_hello(tor_tls_t *tls) { if (tls->server_handshake_count < 3) ++tls->server_handshake_count; if (tls->server_handshake_count == 2) { - if (!tls->negotiated_callback) { - log_warn(LD_BUG, "Got a renegotiation request but we don't" - " have a renegotiation callback set!"); - } - + tor_assert(tls->negotiated_callback); tls->got_renegotiate = 1; } @@ -1380,8 +1376,8 @@ tor_tls_state_changed_callback(const SSL *ssl, int type, int val) if (type == SSL_CB_ACCEPT_LOOP && ssl->state == SSL3_ST_SW_SRVR_HELLO_A) { - /* Call tor_tls_got_client_hello() for every SSL ClientHello we - receive. */ + /* Call tor_tls_got_server_hello() for every SSL ServerHello we + send. */ tor_tls_t *tls = tor_tls_get_by_ssl(ssl); if (!tls) { @@ -1389,7 +1385,7 @@ tor_tls_state_changed_callback(const SSL *ssl, int type, int val) return; } - tor_tls_got_client_hello(tls); + tor_tls_got_server_hello(tls); } #endif @@ -1660,10 +1656,8 @@ 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); - } + tor_assert(tls->server_handshake_count == 2); + /* XXX tor_assert(err == TOR_TLS_WANTREAD); */ /* Renegotiation happened! */ log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls));

1 0

[tor/master] Revert "Get rid of tor_tls_block_renegotiation()."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 021ff31ba6c303ebf13e12e691ea74ca4b39a693 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:21 2011 -0500 Revert "Get rid of tor_tls_block_renegotiation()." This reverts commit 340809dd224b244675496e301d3ba154a6fe68d0. --- src/common/tortls.c | 10 ++++++++++ src/common/tortls.h | 1 + src/or/connection_or.c | 5 +++++ 3 files changed, 16 insertions(+), 0 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index ddb5ea1..9caf930 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1572,6 +1572,16 @@ tor_tls_unblock_renegotiation(tor_tls_t *tls) } } +/** If this version of openssl supports it, turn off renegotiation on + * tls. (Our protocol never requires this for security, but it's nice + * to use belt-and-suspenders here.) + */ +void +tor_tls_block_renegotiation(tor_tls_t *tls) +{ + tls->ssl->s3->flags &= ~SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION; +} + void tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls) { diff --git a/src/common/tortls.h b/src/common/tortls.h index e558df7..673f18d 100644 --- a/src/common/tortls.h +++ b/src/common/tortls.h @@ -77,6 +77,7 @@ int tor_tls_handshake(tor_tls_t *tls); int tor_tls_finish_handshake(tor_tls_t *tls); int tor_tls_renegotiate(tor_tls_t *tls); void tor_tls_unblock_renegotiation(tor_tls_t *tls); +void tor_tls_block_renegotiation(tor_tls_t *tls); void tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls); int tor_tls_shutdown(tor_tls_t *tls); int tor_tls_get_pending_bytes(tor_tls_t *tls); diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 992db9a..cbe678d 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -1149,6 +1149,10 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) or_connection_t *conn = _conn; (void)tls; + /* Don't invoke this again. */ + tor_tls_set_renegotiate_callback(tls, NULL, NULL); + tor_tls_block_renegotiation(tls); + if (connection_tls_finish_handshake(conn) < 0) { /* XXXX_TLS double-check that it's ok to do this from inside read. */ /* XXXX_TLS double-check that this verifies certificates. */ @@ -1537,6 +1541,7 @@ connection_tls_finish_handshake(or_connection_t *conn) connection_or_init_conn_from_address(conn, &conn->_base.addr, conn->_base.port, digest_rcvd, 0); } + tor_tls_block_renegotiation(conn->tls); return connection_or_set_state_open(conn); } else { conn->_base.state = OR_CONN_STATE_OR_HANDSHAKING_V2;

1 0

[tor/master] Revert "Detect and deny excess renegotiations attempts."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit e09dd43ab38e2f1a23010463b1188a1d3631e960 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:21 2011 -0500 Revert "Detect and deny excess renegotiations attempts." This reverts commit ecd239e3b577705e0669d47293a2e755cf93cec0. --- src/common/tortls.c | 20 +++++--------------- 1 files changed, 5 insertions(+), 15 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index 9caf930..c0ff4e1 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -146,7 +146,7 @@ struct tor_tls_t { /** True iff we should call negotiated_callback when we're done reading. */ unsigned int got_renegotiate:1; /** Incremented every time we start the server side of a handshake. */ - unsigned int server_handshake_count:2; + uint8_t server_handshake_count; size_t wantwrite_n; /**< 0 normally, >0 if we returned wantwrite last * time. */ /** Last values retrieved from BIO_number_read()/write(); see @@ -1318,13 +1318,11 @@ tor_tls_client_is_using_v2_ciphers(const SSL *ssl, const char *address) static void tor_tls_got_server_hello(tor_tls_t *tls) { - if (tls->server_handshake_count < 3) - ++tls->server_handshake_count; - - if (tls->server_handshake_count == 2) { - tor_assert(tls->negotiated_callback); + /* Check whether we're watching for renegotiates. If so, this is one! */ + if (tls->negotiated_callback) tls->got_renegotiate = 1; - } + if (tls->server_handshake_count < 127) /*avoid any overflow possibility*/ + ++tls->server_handshake_count; /* Now check the cipher list. */ if (tor_tls_client_is_using_v2_ciphers(tls->ssl, ADDR(tls))) { @@ -1659,14 +1657,6 @@ 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

1 0

[tor/master] Revert "Detect renegotiation when it actually happens."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 9727d21f68d0ef91f9c9002bebde425477bc4c6f Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:21 2011 -0500 Revert "Detect renegotiation when it actually happens." This reverts commit 4fd79f9def28996552b5739792f428c2514de1f6. --- src/common/tortls.c | 29 ++++++++++------------------- 1 files changed, 10 insertions(+), 19 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index c0ff4e1..e26fd1f 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1638,28 +1638,19 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len) tor_assert(tls->state == TOR_TLS_ST_OPEN); tor_assert(len<INT_MAX); r = SSL_read(tls->ssl, cp, (int)len); - if (r > 0) /* return the number of characters read */ - return r; - - /* If we got here, SSL_read() did not go as expected. */ - - err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET); - + if (r > 0) { #ifdef V2_HANDSHAKE_SERVER - if (tls->got_renegotiate) { - tor_assert(tls->server_handshake_count == 2); - /* XXX tor_assert(err == TOR_TLS_WANTREAD); */ - - /* Renegotiation happened! */ - log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls)); - if (tls->negotiated_callback) - tls->negotiated_callback(tls, tls->callback_arg); - tls->got_renegotiate = 0; - + if (tls->got_renegotiate) { + /* Renegotiation happened! */ + log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls)); + if (tls->negotiated_callback) + tls->negotiated_callback(tls, tls->callback_arg); + tls->got_renegotiate = 0; + } +#endif return r; } -#endif - + err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET); if (err == _TOR_TLS_ZERORETURN || err == TOR_TLS_CLOSE) { log_debug(LD_NET,"read returned r=%d; TLS is closed",r); tls->state = TOR_TLS_ST_CLOSED;

1 0

[tor/master] Merge remote-tracking branch 'public/revert_4312'
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 8bb853b2a23e56505d598ee9c38ce56b4afe248c Merge: 299034e 0ebcf34 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Dec 7 21:12:20 2011 -0500 Merge remote-tracking branch 'public/revert_4312' src/common/compat_libevent.c | 59 +------------- src/common/compat_libevent.h | 6 +- src/common/tortls.c | 177 +++++++++++++++++++----------------------- src/common/tortls.h | 5 +- src/common/util.c | 4 +- src/or/connection_or.c | 51 +++--------- src/or/or.h | 2 - 7 files changed, 102 insertions(+), 202 deletions(-)

1 0

[tor/master] Revert "Refactor the SSL_set_info_callback() callbacks."
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 0ebcf345ce6087deeb9f1a1a54b9e6d003822fc3 Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 6 19:49:21 2011 -0500 Revert "Refactor the SSL_set_info_callback() callbacks." This reverts commit 69a821ea1c9357acdd5aa1c9e23fd030b01cb5a9. --- src/common/tortls.c | 97 ++++++++++++++++++++++++++++----------------------- 1 files changed, 53 insertions(+), 44 deletions(-) diff --git a/src/common/tortls.c b/src/common/tortls.c index e26fd1f..e4992ef 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -1312,29 +1312,55 @@ tor_tls_client_is_using_v2_ciphers(const SSL *ssl, const char *address) return 1; } -/** We sent the ServerHello part of an SSL handshake. This might mean - * that we completed a renegotiation and appropriate actions must be - * taken. */ static void -tor_tls_got_server_hello(tor_tls_t *tls) +tor_tls_debug_state_callback(const SSL *ssl, int type, int val) { - /* Check whether we're watching for renegotiates. If so, this is one! */ - if (tls->negotiated_callback) - tls->got_renegotiate = 1; - if (tls->server_handshake_count < 127) /*avoid any overflow possibility*/ - ++tls->server_handshake_count; + log_debug(LD_HANDSHAKE, "SSL %p is now in state %s [type=%d,val=%d].", + ssl, ssl_state_to_string(ssl->state), type, val); +} + +/** Invoked when we're accepting a connection on ssl, and the connection + * changes state. We use this: + * <ul><li>To alter the state of the handshake partway through, so we + * do not send or request extra certificates in v2 handshakes.</li> + * <li>To detect renegotiation</li></ul> + */ +static void +tor_tls_server_info_callback(const SSL *ssl, int type, int val) +{ + tor_tls_t *tls; + (void) val; + + tor_tls_debug_state_callback(ssl, type, val); + + if (type != SSL_CB_ACCEPT_LOOP) + return; + if (ssl->state != SSL3_ST_SW_SRVR_HELLO_A) + return; + + tls = tor_tls_get_by_ssl(ssl); + if (tls) { + /* Check whether we're watching for renegotiates. If so, this is one! */ + if (tls->negotiated_callback) + tls->got_renegotiate = 1; + if (tls->server_handshake_count < 127) /*avoid any overflow possibility*/ + ++tls->server_handshake_count; + } else { + log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!"); + return; + } /* Now check the cipher list. */ - if (tor_tls_client_is_using_v2_ciphers(tls->ssl, ADDR(tls))) { + if (tor_tls_client_is_using_v2_ciphers(ssl, ADDR(tls))) { /*XXXX_TLS keep this from happening more than once! */ /* Yes, we're casting away the const from ssl. This is very naughty of us. * Let's hope openssl doesn't notice! */ /* Set SSL_MODE_NO_AUTO_CHAIN to keep from sending back any extra certs. */ - SSL_set_mode((SSL*) tls->ssl, SSL_MODE_NO_AUTO_CHAIN); + SSL_set_mode((SSL*) ssl, SSL_MODE_NO_AUTO_CHAIN); /* Don't send a hello request. */ - SSL_set_verify((SSL*) tls->ssl, SSL_VERIFY_NONE, NULL); + SSL_set_verify((SSL*) ssl, SSL_VERIFY_NONE, NULL); if (tls) { tls->wasV2Handshake = 1; @@ -1349,35 +1375,6 @@ tor_tls_got_server_hello(tor_tls_t *tls) } #endif -/** This is a callback function for SSL_set_info_callback() and it - * will be called in every SSL state change. - * It logs the SSL state change, and executes any actions that must be - * taken. */ -static void -tor_tls_state_changed_callback(const SSL *ssl, int type, int val) -{ - log_debug(LD_HANDSHAKE, "SSL %p is now in state %s [type=%d,val=%d].", - ssl, ssl_state_to_string(ssl->state), type, val); - -#ifdef V2_HANDSHAKE_SERVER - if (type == SSL_CB_ACCEPT_LOOP && - ssl->state == SSL3_ST_SW_SRVR_HELLO_A) { - - /* Call tor_tls_got_server_hello() for every SSL ServerHello we - send. */ - - tor_tls_t *tls = tor_tls_get_by_ssl(ssl); - if (!tls) { - log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!"); - return; - } - - tor_tls_got_server_hello(tls); - } -#endif - -} - /** Replace *ciphers with a new list of SSL ciphersuites: specifically, * a list designed to mimic a common web browser. Some of the ciphers in the * list won't actually be implemented by OpenSSL: that's okay so long as the @@ -1519,8 +1516,14 @@ tor_tls_new(int sock, int isServer) log_warn(LD_NET, "Newly created BIO has read count %lu, write count %lu", result->last_read_count, result->last_write_count); } - - SSL_set_info_callback(result->ssl, tor_tls_state_changed_callback); +#ifdef V2_HANDSHAKE_SERVER + if (isServer) { + SSL_set_info_callback(result->ssl, tor_tls_server_info_callback); + } else +#endif + { + SSL_set_info_callback(result->ssl, tor_tls_debug_state_callback); + } /* Not expected to get called. */ tls_log_errors(NULL, LOG_WARN, LD_NET, "creating tor_tls_t object"); @@ -1550,7 +1553,13 @@ tor_tls_set_renegotiate_callback(tor_tls_t *tls, tls->negotiated_callback = cb; tls->callback_arg = arg; tls->got_renegotiate = 0; - SSL_set_info_callback(tls->ssl, tor_tls_state_changed_callback); +#ifdef V2_HANDSHAKE_SERVER + if (cb) { + SSL_set_info_callback(tls->ssl, tor_tls_server_info_callback); + } else { + SSL_set_info_callback(tls->ssl, tor_tls_debug_state_callback); + } +#endif } /** If this version of openssl requires it, turn on renegotiation on

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[tor/master] Remove 4312 from the changelog.
by nickm＠torproject.org 08 Dec '11

08 Dec '11

commit 00fae9a500475d7ebf1dd0f56c7fc78e2567c818 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Dec 7 21:10:32 2011 -0500 Remove 4312 from the changelog. --- ChangeLog | 9 +-------- 1 files changed, 1 insertions(+), 8 deletions(-) diff --git a/ChangeLog b/ChangeLog index 9a7d50a..ba0ae18 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,4 +1,4 @@ -Changes in version 0.2.3.9-alpha - 2011-1?-?? +Changes in version 0.2.3.9-alpha - 2011-12-?? o Major features: - When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode implementation. It makes AES_CTR about 7% faster than our old one @@ -9,15 +9,8 @@ Changes in version 0.2.3.9-alpha - 2011-1?-?? censorship by allowing bridges to use protocol obfuscation plugins. It implements the 'managed proxy' part of proposal 180. Implements ticket 3472. - - Block excess renegotiations even if they are RFC5746 compliant. - This security fix mitigates potential SSL Denial of Service attacks - that use SSL renegotiation as a way of forcing the server to perform - unneeded computationally expensive SSL handshakes. Implements - ticket 4312. o Major bugfixes: - - Teach Tor how to notice excess renegotiation attempts before it - receives the first data SSL record. Fixes part of ticket 4312. - Only use the EVP interface when AES acceleration is enabled, to avoid a 5-7% performance regression. Resolves issue 4525; bugfix on 0.2.3.8-alpha.

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[tor/master] clarify a debug line
by arma＠torproject.org 08 Dec '11

08 Dec '11

commit 299034edf5e05c81d535fc7d0b2120b6a2810477 Author: Roger Dingledine <arma(a)torproject.org> Date: Wed Dec 7 18:12:11 2011 -0500 clarify a debug line --- src/or/circuitbuild.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index 7934a2e..a9e5d22 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -2524,7 +2524,8 @@ onionskin_answer(or_circuit_t *circ, uint8_t cell_type, const char *payload, append_cell_to_circuit_queue(TO_CIRCUIT(circ), circ->p_conn, &cell, CELL_DIRECTION_IN, 0); - log_debug(LD_CIRC,"Finished sending 'created' cell."); + log_debug(LD_CIRC,"Finished sending '%s' cell.", + circ->is_first_hop ? "created_fast" : "created"); if (!is_local_addr(&circ->p_conn->_base.addr) && !connection_or_nonopen_was_started_here(circ->p_conn)) {

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