- tor-commits - lists.torproject.org

[tor/release-0.2.2] Don't use any OR connection which sent us a CREATE_FAST cell for an EXTEND
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit af12c39d6de5bbcd24915db3c4cc9404f102ac02 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Sun Oct 23 14:27:56 2011 -0700 Don't use any OR connection which sent us a CREATE_FAST cell for an EXTEND Fix suggested by Nick Mathewson. --- changes/issue-2011-10-19L | 9 +++++++++ src/or/command.c | 6 ++++++ src/or/connection_or.c | 5 +++++ src/or/or.h | 4 ++++ 4 files changed, 24 insertions(+), 0 deletions(-) diff --git a/changes/issue-2011-10-19L b/changes/issue-2011-10-19L index 972823e..1fefd72 100644 --- a/changes/issue-2011-10-19L +++ b/changes/issue-2011-10-19L @@ -10,3 +10,12 @@ upgrade. Fixes CVE-2011-2768. Bugfix on FIXME; found by frosty_un. + - Don't use any OR connection on which we have received a + CREATE_FAST cell to satisfy an EXTEND request. Previously, we + would not consider whether a connection appears to be from a + client or bridge when deciding whether to use that connection to + satisfy an EXTEND request. Mitigates CVE-2011-2768, by + preventing an attacker from determining whether an unpatched + client is connected to a patched relay. Bugfix on FIXME; found + by frosty_un. + diff --git a/src/or/command.c b/src/or/command.c index 61b898c..a17a3a6 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -285,7 +285,13 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn) * a CPU worker. */ char keys[CPATH_KEY_MATERIAL_LEN]; char reply[DIGEST_LEN*2]; + tor_assert(cell->command == CELL_CREATE_FAST); + + /* Make sure we never try to use the OR connection on which we + * received this cell to satisfy an EXTEND request, */ + conn->is_connection_with_client = 1; + if (fast_server_handshake(cell->payload, (uint8_t*)reply, (uint8_t*)keys, sizeof(keys))<0) { log_warn(LD_OR,"Failed to generate key material. Closing."); diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 95cc02e..35f6da9 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -519,6 +519,11 @@ connection_or_get_for_extend(const char *digest, tor_assert(tor_memeq(conn->identity_digest, digest, DIGEST_LEN)); if (conn->_base.marked_for_close) continue; + /* Never return a connection on which the other end appears to be + * a client. */ + if (conn->is_connection_with_client) { + continue; + } /* Never return a non-open connection. */ if (conn->_base.state != OR_CONN_STATE_OPEN) { /* If the address matches, don't launch a new connection for this diff --git a/src/or/or.h b/src/or/or.h index 4105ff4..72e4c63 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -1031,6 +1031,10 @@ typedef struct or_connection_t { * because the connection is too old, or because there's a better one, etc. */ unsigned int is_bad_for_new_circs:1; + /** True iff we have decided that the other end of this connection + * is a client. Connections with this flag set should never be used + * to satisfy an EXTEND request. */ + unsigned int is_connection_with_client:1; uint8_t link_proto; /**< What protocol version are we using? 0 for * "none negotiated yet." */ circid_t next_circ_id; /**< Which circ_id do we try to use next on

1 0

[tor/release-0.2.2] Reject create cells on outgoing OR connections from bridges
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit a74e7fd40f1a77eb4000d8216bb5b80cdd8a6193 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Sun Oct 23 15:21:49 2011 -0700 Reject create cells on outgoing OR connections from bridges --- changes/issue-2011-10-23G | 9 +++++++++ src/or/command.c | 7 +++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/changes/issue-2011-10-23G b/changes/issue-2011-10-23G new file mode 100644 index 0000000..45f8675 --- /dev/null +++ b/changes/issue-2011-10-23G @@ -0,0 +1,9 @@ + o Security fixes: + + - Reject CREATE and CREATE_FAST cells on outgoing OR connections + from a bridge to a relay. Previously, we would accept them and + handle them normally, thereby allowing a malicious relay to + easily distinguish bridges which connect to it from clients. + Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha, when bridges were + implemented; found by frosty_un. + diff --git a/src/or/command.c b/src/or/command.c index a17a3a6..54f23bb 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -219,6 +219,7 @@ static void command_process_create_cell(cell_t *cell, or_connection_t *conn) { or_circuit_t *circ; + or_options_t *options = get_options(); int id_is_high; if (we_are_hibernating()) { @@ -230,9 +231,11 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn) return; } - if (!server_mode(get_options())) { + if (!server_mode(options) || + (!public_server_mode(options) && conn->is_outgoing)) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Received create cell (type %d) from %s:%d, but we're a client. " + "Received create cell (type %d) from %s:%d, but we're connected " + "to it as a client. " "Sending back a destroy.", (int)cell->command, conn->_base.address, conn->_base.port); connection_or_send_destroy(cell->circ_id, conn,

1 0

[tor/maint-0.2.2] Don't give the Guard flag to relays without the CVE-2011-2768 fix
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit 00fffbc1a15e2696a89c721d0c94dc333ff419ef Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Tue Oct 25 00:24:15 2011 -0700 Don't give the Guard flag to relays without the CVE-2011-2768 fix --- changes/issue-2011-10-19L | 7 ++++ src/or/dirserv.c | 71 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 77 insertions(+), 1 deletions(-) diff --git a/changes/issue-2011-10-19L b/changes/issue-2011-10-19L index 1fefd72..b879c9d 100644 --- a/changes/issue-2011-10-19L +++ b/changes/issue-2011-10-19L @@ -19,3 +19,10 @@ client is connected to a patched relay. Bugfix on FIXME; found by frosty_un. + - Don't assign the Guard flag to relays running a version of Tor + which would use an OR connection on which it has received a + CREATE_FAST cell to satisfy an EXTEND request. Mitigates + CVE-2011-2768, by ensuring that clients will not connect + directly to any relay which an attacker could probe for an + unpatched client's connections. + diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 6607901..fa7f693 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2251,6 +2251,74 @@ get_possible_sybil_list(const smartlist_t *routers) return omit_as_sybil; } +/** Return non-zero iff a relay running the Tor version specified in + * platform is suitable for use as a potential entry guard. */ +static int +is_router_version_good_for_possible_guard(const char *platform) +{ + static int parsed_versions_initialized = 0; + static tor_version_t first_good_0_2_1_guard_version; + static tor_version_t first_good_0_2_2_guard_version; + static tor_version_t first_good_later_guard_version; + + tor_version_t router_version; + + /* XXX023 This block should be extracted into its own function. */ + /* XXXX Begin code copied from tor_version_as_new_as (in routerparse.c) */ + { + char *s, *s2, *start; + char tmp[128]; + + tor_assert(platform); + + if (strcmpstart(platform,"Tor ")) /* nonstandard Tor; be safe and say yes */ + return 1; + + start = (char *)eat_whitespace(platform+3); + if (!*start) return 0; + s = (char *)find_whitespace(start); /* also finds '\0', which is fine */ + s2 = (char*)eat_whitespace(s); + if (!strcmpstart(s2, "(r") || !strcmpstart(s2, "(git-")) + s = (char*)find_whitespace(s2); + + if ((size_t)(s-start+1) >= sizeof(tmp)) /* too big, no */ + return 0; + strlcpy(tmp, start, s-start+1); + + if (tor_version_parse(tmp, &router_version)<0) { + log_info(LD_DIR,"Router version '%s' unparseable.",tmp); + return 1; /* be safe and say yes */ + } + } + /* XXXX End code copied from tor_version_as_new_as (in routerparse.c) */ + + if (!parsed_versions_initialized) { + /* CVE-2011-2769 was fixed on the relay side in Tor versions + * 0.2.1.31, 0.2.2.34, and 0.2.3.6-alpha. */ + tor_assert(tor_version_parse("0.2.1.31", + &first_good_0_2_1_guard_version)>=0); + tor_assert(tor_version_parse("0.2.2.34", + &first_good_0_2_2_guard_version)>=0); + tor_assert(tor_version_parse("0.2.3.6-alpha", + &first_good_later_guard_version)>=0); + + /* Don't parse these constant version strings once for every relay + * for every vote. */ + parsed_versions_initialized = 1; + } + + return ((tor_version_same_series(&first_good_0_2_1_guard_version, + &router_version) && + tor_version_compare(&first_good_0_2_1_guard_version, + &router_version) <= 0) || + (tor_version_same_series(&first_good_0_2_2_guard_version, + &router_version) && + tor_version_compare(&first_good_0_2_2_guard_version, + &router_version) <= 0) || + (tor_version_compare(&first_good_later_guard_version, + &router_version) <= 0)); +} + /** Extract status information from ri and from other authority * functions and store it in rs>. If naming, consider setting * the named flag in rs. @@ -2294,7 +2362,8 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs, (router_get_advertised_bandwidth(ri) >= BANDWIDTH_TO_GUARANTEE_GUARD || router_get_advertised_bandwidth(ri) >= MIN(guard_bandwidth_including_exits, - guard_bandwidth_excluding_exits))) { + guard_bandwidth_excluding_exits)) && + is_router_version_good_for_possible_guard(ri->platform)) { long tk = rep_hist_get_weighted_time_known( ri->cache_info.identity_digest, now); double wfu = rep_hist_get_weighted_fractional_uptime(

1 0

[tor/maint-0.2.2] Add option to give guard flag to relays without the CVE-2011-2768 fix
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit 4684ced1b3fced0543fa65bf01f75c5d81eaf464 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Tue Oct 25 12:33:21 2011 -0700 Add option to give guard flag to relays without the CVE-2011-2768 fix This way, all of the DA operators can upgrade immediately, without nuking every client's set of entry guards as soon as a majority of them upgrade. Until enough guards have upgraded, a majority of dirauths should set this config option so that there are still enough guards in the network. After a few days pass, all dirauths should use the default. --- src/or/config.c | 2 ++ src/or/dirserv.c | 4 +++- src/or/or.h | 4 ++++ 3 files changed, 9 insertions(+), 1 deletions(-) diff --git a/src/or/config.c b/src/or/config.c index 230ccf2..78e4336 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -269,6 +269,8 @@ static config_var_t _option_vars[] = { V(GeoIPFile, FILENAME, SHARE_DATADIR PATH_SEPARATOR "tor" PATH_SEPARATOR "geoip"), #endif + V(GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays, + BOOL, "0"), OBSOLETE("Group"), V(HardwareAccel, BOOL, "0"), V(AccelName, STRING, NULL), diff --git a/src/or/dirserv.c b/src/or/dirserv.c index fa7f693..c427fe2 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2332,6 +2332,7 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs, int naming, int listbadexits, int listbaddirs, int vote_on_hsdirs) { + const or_options_t *options = get_options(); int unstable_version = !tor_version_as_new_as(ri->platform,"0.1.1.16-rc-cvs"); memset(rs, 0, sizeof(routerstatus_t)); @@ -2363,7 +2364,8 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs, router_get_advertised_bandwidth(ri) >= MIN(guard_bandwidth_including_exits, guard_bandwidth_excluding_exits)) && - is_router_version_good_for_possible_guard(ri->platform)) { + (options->GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays || + is_router_version_good_for_possible_guard(ri->platform))) { long tk = rep_hist_get_weighted_time_known( ri->cache_info.identity_digest, now); double wfu = rep_hist_get_weighted_fractional_uptime( diff --git a/src/or/or.h b/src/or/or.h index 8638f20..7d50e1f 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -2672,6 +2672,10 @@ typedef struct { * number of servers per IP address shared * with an authority. */ + /** Should we assign the Guard flag to relays which would allow + * exploitation of CVE-2011-2768 against their clients? */ + int GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays; + char *AccountingStart; /**< How long is the accounting interval, and when * does it start? */ uint64_t AccountingMax; /**< How many bytes do we allow per accounting

1 0

[tor/maint-0.2.2] Don't use any OR connection which sent us a CREATE_FAST cell for an EXTEND
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit af12c39d6de5bbcd24915db3c4cc9404f102ac02 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Sun Oct 23 14:27:56 2011 -0700 Don't use any OR connection which sent us a CREATE_FAST cell for an EXTEND Fix suggested by Nick Mathewson. --- changes/issue-2011-10-19L | 9 +++++++++ src/or/command.c | 6 ++++++ src/or/connection_or.c | 5 +++++ src/or/or.h | 4 ++++ 4 files changed, 24 insertions(+), 0 deletions(-) diff --git a/changes/issue-2011-10-19L b/changes/issue-2011-10-19L index 972823e..1fefd72 100644 --- a/changes/issue-2011-10-19L +++ b/changes/issue-2011-10-19L @@ -10,3 +10,12 @@ upgrade. Fixes CVE-2011-2768. Bugfix on FIXME; found by frosty_un. + - Don't use any OR connection on which we have received a + CREATE_FAST cell to satisfy an EXTEND request. Previously, we + would not consider whether a connection appears to be from a + client or bridge when deciding whether to use that connection to + satisfy an EXTEND request. Mitigates CVE-2011-2768, by + preventing an attacker from determining whether an unpatched + client is connected to a patched relay. Bugfix on FIXME; found + by frosty_un. + diff --git a/src/or/command.c b/src/or/command.c index 61b898c..a17a3a6 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -285,7 +285,13 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn) * a CPU worker. */ char keys[CPATH_KEY_MATERIAL_LEN]; char reply[DIGEST_LEN*2]; + tor_assert(cell->command == CELL_CREATE_FAST); + + /* Make sure we never try to use the OR connection on which we + * received this cell to satisfy an EXTEND request, */ + conn->is_connection_with_client = 1; + if (fast_server_handshake(cell->payload, (uint8_t*)reply, (uint8_t*)keys, sizeof(keys))<0) { log_warn(LD_OR,"Failed to generate key material. Closing."); diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 95cc02e..35f6da9 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -519,6 +519,11 @@ connection_or_get_for_extend(const char *digest, tor_assert(tor_memeq(conn->identity_digest, digest, DIGEST_LEN)); if (conn->_base.marked_for_close) continue; + /* Never return a connection on which the other end appears to be + * a client. */ + if (conn->is_connection_with_client) { + continue; + } /* Never return a non-open connection. */ if (conn->_base.state != OR_CONN_STATE_OPEN) { /* If the address matches, don't launch a new connection for this diff --git a/src/or/or.h b/src/or/or.h index 4105ff4..72e4c63 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -1031,6 +1031,10 @@ typedef struct or_connection_t { * because the connection is too old, or because there's a better one, etc. */ unsigned int is_bad_for_new_circs:1; + /** True iff we have decided that the other end of this connection + * is a client. Connections with this flag set should never be used + * to satisfy an EXTEND request. */ + unsigned int is_connection_with_client:1; uint8_t link_proto; /**< What protocol version are we using? 0 for * "none negotiated yet." */ circid_t next_circ_id; /**< Which circ_id do we try to use next on

1 0

[tor/maint-0.2.2] Mark which OR connections are outgoing
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit c05bb53508f5fe3e570a285e6c9ead452ded0e43 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Sun Oct 23 14:58:00 2011 -0700 Mark which OR connections are outgoing --- src/or/connection_or.c | 2 ++ src/or/or.h | 2 ++ 2 files changed, 4 insertions(+), 0 deletions(-) diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 35f6da9..f019c79 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -776,6 +776,8 @@ connection_or_connect(const tor_addr_t *_addr, uint16_t port, conn->_base.state = OR_CONN_STATE_CONNECTING; control_event_or_conn_status(conn, OR_CONN_EVENT_LAUNCHED, 0); + conn->is_outgoing = 1; + if (options->HttpsProxy) { /* we shouldn't connect directly. use the https proxy instead. */ tor_addr_from_ipv4h(&addr, options->HttpsProxyAddr); diff --git a/src/or/or.h b/src/or/or.h index 72e4c63..edbb73c 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -1035,6 +1035,8 @@ typedef struct or_connection_t { * is a client. Connections with this flag set should never be used * to satisfy an EXTEND request. */ unsigned int is_connection_with_client:1; + /** True iff this is an outgoing connection. */ + unsigned int is_outgoing:1; uint8_t link_proto; /**< What protocol version are we using? 0 for * "none negotiated yet." */ circid_t next_circ_id; /**< Which circ_id do we try to use next on

1 0

[tor/maint-0.2.2] Merge branch 'maint-0.2.1_secfix' into maint-0.2.2_secfix
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit df05e5ef4d5e379e50b38e29fa23228e5b260e8a Merge: f85c561 a74e7fd Author: Sebastian Hahn <sebastian(a)torproject.org> Date: Wed Oct 26 23:30:27 2011 +0200 Merge branch 'maint-0.2.1_secfix' into maint-0.2.2_secfix Conflicts: src/or/connection_or.c changes/issue-2011-10-19L | 21 ++++++++++ changes/issue-2011-10-23G | 9 ++++ src/common/tortls.c | 93 ++++++++++++++++++++++++++------------------- src/or/command.c | 13 +++++- src/or/connection_or.c | 7 +++ src/or/or.h | 6 +++ 6 files changed, 108 insertions(+), 41 deletions(-) diff --cc src/common/tortls.c index 10f4440,cc805f8..352c3d6 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@@ -681,13 -655,16 +684,14 @@@ tor_tls_context_init(int is_public_serv rv2 = tor_tls_context_init_one(&client_tls_context, client_identity, - key_lifetime); + key_lifetime, + 1); } - return rv1 < rv2 ? rv1 : rv2; + return MIN(rv1, rv2); } -/** Create a new TLS context for use with Tor TLS handshakes. - * identity should be set to the identity key used to sign the - * certificate. +/** Create a new global TLS context. * * You can call this function multiple times. Each time you call it, * it generates new certificates; all new connections will use @@@ -785,30 -769,33 +796,34 @@@ tor_tls_context_new(crypto_pk_env_t *id #ifdef SSL_MODE_RELEASE_BUFFERS SSL_CTX_set_mode(result->ctx, SSL_MODE_RELEASE_BUFFERS); #endif - if (cert && !SSL_CTX_use_certificate(result->ctx,cert)) - goto error; - X509_free(cert); /* We just added a reference to cert. */ - cert=NULL; - if (idcert) { - X509_STORE *s = SSL_CTX_get_cert_store(result->ctx); - tor_assert(s); - X509_STORE_add_cert(s, idcert); - X509_free(idcert); /* The context now owns the reference to idcert */ - idcert = NULL; + if (! is_client) { + if (cert && !SSL_CTX_use_certificate(result->ctx,cert)) + goto error; + X509_free(cert); /* We just added a reference to cert. */ + cert=NULL; + if (idcert) { + X509_STORE *s = SSL_CTX_get_cert_store(result->ctx); + tor_assert(s); + X509_STORE_add_cert(s, idcert); + X509_free(idcert); /* The context now owns the reference to idcert */ + idcert = NULL; + } } SSL_CTX_set_session_cache_mode(result->ctx, SSL_SESS_CACHE_OFF); - tor_assert(rsa); - if (!(pkey = _crypto_pk_env_get_evp_pkey(rsa,1))) - goto error; - if (!SSL_CTX_use_PrivateKey(result->ctx, pkey)) - goto error; - EVP_PKEY_free(pkey); - pkey = NULL; - if (!SSL_CTX_check_private_key(result->ctx)) - goto error; + if (!is_client) { + tor_assert(rsa); + if (!(pkey = _crypto_pk_env_get_evp_pkey(rsa,1))) + goto error; + if (!SSL_CTX_use_PrivateKey(result->ctx, pkey)) + goto error; + EVP_PKEY_free(pkey); + pkey = NULL; + if (!SSL_CTX_check_private_key(result->ctx)) + goto error; + } { crypto_dh_env_t *dh = crypto_dh_new(DH_TYPE_TLS); + tor_assert(dh); SSL_CTX_set_tmp_dh(result->ctx, _crypto_dh_env_get_dh(dh)); crypto_dh_free(dh); } diff --cc src/or/connection_or.c index c019f65,f019c79..27a34d3 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@@ -808,19 -776,12 +813,21 @@@ connection_or_connect(const tor_addr_t conn->_base.state = OR_CONN_STATE_CONNECTING; control_event_or_conn_status(conn, OR_CONN_EVENT_LAUNCHED, 0); + conn->is_outgoing = 1; + - if (options->HttpsProxy) { - /* we shouldn't connect directly. use the https proxy instead. */ - tor_addr_from_ipv4h(&addr, options->HttpsProxyAddr); - port = options->HttpsProxyPort; + /* use a proxy server if available */ + if (options->HTTPSProxy) { + using_proxy = 1; + tor_addr_copy(&addr, &options->HTTPSProxyAddr); + port = options->HTTPSProxyPort; + } else if (options->Socks4Proxy) { + using_proxy = 1; + tor_addr_copy(&addr, &options->Socks4ProxyAddr); + port = options->Socks4ProxyPort; + } else if (options->Socks5Proxy) { + using_proxy = 1; + tor_addr_copy(&addr, &options->Socks5ProxyAddr); + port = options->Socks5ProxyPort; } switch (connection_connect(TO_CONN(conn), conn->_base.address, diff --cc src/or/or.h index 31deb89,edbb73c..8638f20 --- a/src/or/or.h +++ b/src/or/or.h @@@ -1062,12 -1028,15 +1062,18 @@@ typedef struct or_connection_t * NETINFO cell listed the address we're connected to as recognized. */ unsigned int is_canonical:1; /** True iff this connection shouldn't get any new circs attached to it, - * because the connection is too old, or because there's a better one, etc. + * because the connection is too old, or because there's a better one. + * More generally, this flag is used to note an unhealthy connection; + * for example, if a bad connection fails we shouldn't assume that the + * router itself has a problem. */ unsigned int is_bad_for_new_circs:1; + /** True iff we have decided that the other end of this connection + * is a client. Connections with this flag set should never be used + * to satisfy an EXTEND request. */ + unsigned int is_connection_with_client:1; + /** True iff this is an outgoing connection. */ + unsigned int is_outgoing:1; uint8_t link_proto; /**< What protocol version are we using? 0 for * "none negotiated yet." */ circid_t next_circ_id; /**< Which circ_id do we try to use next on

1 0

[tor/maint-0.2.2] Reject create cells on outgoing OR connections from bridges
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit a74e7fd40f1a77eb4000d8216bb5b80cdd8a6193 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Sun Oct 23 15:21:49 2011 -0700 Reject create cells on outgoing OR connections from bridges --- changes/issue-2011-10-23G | 9 +++++++++ src/or/command.c | 7 +++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/changes/issue-2011-10-23G b/changes/issue-2011-10-23G new file mode 100644 index 0000000..45f8675 --- /dev/null +++ b/changes/issue-2011-10-23G @@ -0,0 +1,9 @@ + o Security fixes: + + - Reject CREATE and CREATE_FAST cells on outgoing OR connections + from a bridge to a relay. Previously, we would accept them and + handle them normally, thereby allowing a malicious relay to + easily distinguish bridges which connect to it from clients. + Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha, when bridges were + implemented; found by frosty_un. + diff --git a/src/or/command.c b/src/or/command.c index a17a3a6..54f23bb 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -219,6 +219,7 @@ static void command_process_create_cell(cell_t *cell, or_connection_t *conn) { or_circuit_t *circ; + or_options_t *options = get_options(); int id_is_high; if (we_are_hibernating()) { @@ -230,9 +231,11 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn) return; } - if (!server_mode(get_options())) { + if (!server_mode(options) || + (!public_server_mode(options) && conn->is_outgoing)) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Received create cell (type %d) from %s:%d, but we're a client. " + "Received create cell (type %d) from %s:%d, but we're connected " + "to it as a client. " "Sending back a destroy.", (int)cell->command, conn->_base.address, conn->_base.port); connection_or_send_destroy(cell->circ_id, conn,

1 0

[tor/maint-0.2.2] Make tor_version_same_series non-static
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit 4d0f152aadabd431924acb137990081269cffb3d Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Mon Oct 24 23:36:57 2011 -0700 Make tor_version_same_series non-static --- src/or/routerparse.c | 3 +-- src/or/routerparse.h | 1 + 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/or/routerparse.c b/src/or/routerparse.c index aed4fd1..001c4d6 100644 --- a/src/or/routerparse.c +++ b/src/or/routerparse.c @@ -572,7 +572,6 @@ static int check_signature_token(const char *digest, int flags, const char *doctype); static crypto_pk_env_t *find_dir_signing_key(const char *str, const char *eos); -static int tor_version_same_series(tor_version_t *a, tor_version_t *b); #undef DEBUG_AREA_ALLOC @@ -4556,7 +4555,7 @@ tor_version_compare(tor_version_t *a, tor_version_t *b) /** Return true iff versions a and b belong to the same series. */ -static int +int tor_version_same_series(tor_version_t *a, tor_version_t *b) { tor_assert(a); diff --git a/src/or/routerparse.h b/src/or/routerparse.h index 8b8cde2..527de5d 100644 --- a/src/or/routerparse.h +++ b/src/or/routerparse.h @@ -47,6 +47,7 @@ version_status_t tor_version_is_obsolete(const char *myversion, int tor_version_parse(const char *s, tor_version_t *out); int tor_version_as_new_as(const char *platform, const char *cutoff); int tor_version_compare(tor_version_t *a, tor_version_t *b); +int tor_version_same_series(tor_version_t *a, tor_version_t *b); void sort_version_list(smartlist_t *lst, int remove_duplicates); void assert_addr_policy_ok(smartlist_t *t); void dump_distinct_digest_count(int severity);

1 0

[tor/maint-0.2.2] Don't send a certificate chain on outgoing TLS connections from non-relays
by arma＠torproject.org 27 Oct '11

27 Oct '11

commit 638fdedcf16cf7d6f7c586d36f7ef335c1c9714f Author: Nick Mathewson <nickm(a)torproject.org> Date: Sun Oct 23 16:06:06 2011 +0000 Don't send a certificate chain on outgoing TLS connections from non-relays --- changes/issue-2011-10-19L | 12 ++++++ src/common/tortls.c | 93 ++++++++++++++++++++++++++------------------- 2 files changed, 66 insertions(+), 39 deletions(-) diff --git a/changes/issue-2011-10-19L b/changes/issue-2011-10-19L new file mode 100644 index 0000000..972823e --- /dev/null +++ b/changes/issue-2011-10-19L @@ -0,0 +1,12 @@ + o Security fixes: + + - Don't send TLS certificate chains on outgoing OR connections + from clients and bridges. Previously, each client or bridge + would use a single cert chain for all outgoing OR connections + for up to 24 hours, which allowed any relay connected to by a + client or bridge to determine which entry guards it is using. + This is a potential user-tracing bug for *all* users; everyone + who uses Tor's client or hidden service functionality should + upgrade. Fixes CVE-2011-2768. Bugfix on FIXME; found by + frosty_un. + diff --git a/src/common/tortls.c b/src/common/tortls.c index c78a9ec..cc805f8 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -186,9 +186,11 @@ static X509* tor_tls_create_certificate(crypto_pk_env_t *rsa, static void tor_tls_unblock_renegotiation(tor_tls_t *tls); static int tor_tls_context_init_one(tor_tls_context_t **ppcontext, crypto_pk_env_t *identity, - unsigned int key_lifetime); + unsigned int key_lifetime, + int is_client); static tor_tls_context_t *tor_tls_context_new(crypto_pk_env_t *identity, - unsigned int key_lifetime); + unsigned int key_lifetime, + int is_client); /** Global TLS contexts. We keep them here because nobody else needs * to touch them. */ @@ -624,7 +626,7 @@ tor_tls_context_init(int is_public_server, rv1 = tor_tls_context_init_one(&server_tls_context, server_identity, - key_lifetime); + key_lifetime, 0); if (rv1 >= 0) { new_ctx = server_tls_context; @@ -640,7 +642,8 @@ tor_tls_context_init(int is_public_server, if (server_identity != NULL) { rv1 = tor_tls_context_init_one(&server_tls_context, server_identity, - key_lifetime); + key_lifetime, + 0); } else { tor_tls_context_t *old_ctx = server_tls_context; server_tls_context = NULL; @@ -652,7 +655,8 @@ tor_tls_context_init(int is_public_server, rv2 = tor_tls_context_init_one(&client_tls_context, client_identity, - key_lifetime); + key_lifetime, + 1); } return rv1 < rv2 ? rv1 : rv2; @@ -669,10 +673,12 @@ tor_tls_context_init(int is_public_server, static int tor_tls_context_init_one(tor_tls_context_t **ppcontext, crypto_pk_env_t *identity, - unsigned int key_lifetime) + unsigned int key_lifetime, + int is_client) { tor_tls_context_t *new_ctx = tor_tls_context_new(identity, - key_lifetime); + key_lifetime, + is_client); tor_tls_context_t *old_ctx = *ppcontext; if (new_ctx != NULL) { @@ -694,7 +700,8 @@ tor_tls_context_init_one(tor_tls_context_t **ppcontext, * certificate. */ static tor_tls_context_t * -tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime) +tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime, + int is_client) { crypto_pk_env_t *rsa = NULL; EVP_PKEY *pkey = NULL; @@ -711,22 +718,26 @@ tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime) goto error; if (crypto_pk_generate_key(rsa)<0) goto error; - /* Create certificate signed by identity key. */ - cert = tor_tls_create_certificate(rsa, identity, nickname, nn2, - key_lifetime); - /* Create self-signed certificate for identity key. */ - idcert = tor_tls_create_certificate(identity, identity, nn2, nn2, - IDENTITY_CERT_LIFETIME); - if (!cert || !idcert) { - log(LOG_WARN, LD_CRYPTO, "Error creating certificate"); - goto error; + if (!is_client) { + /* Create certificate signed by identity key. */ + cert = tor_tls_create_certificate(rsa, identity, nickname, nn2, + key_lifetime); + /* Create self-signed certificate for identity key. */ + idcert = tor_tls_create_certificate(identity, identity, nn2, nn2, + IDENTITY_CERT_LIFETIME); + if (!cert || !idcert) { + log(LOG_WARN, LD_CRYPTO, "Error creating certificate"); + goto error; + } } result = tor_malloc_zero(sizeof(tor_tls_context_t)); result->refcnt = 1; - result->my_cert = X509_dup(cert); - result->my_id_cert = X509_dup(idcert); - result->key = crypto_pk_dup_key(rsa); + if (!is_client) { + result->my_cert = X509_dup(cert); + result->my_id_cert = X509_dup(idcert); + result->key = crypto_pk_dup_key(rsa); + } #ifdef EVERYONE_HAS_AES /* Tell OpenSSL to only use TLS1 */ @@ -758,27 +769,31 @@ tor_tls_context_new(crypto_pk_env_t *identity, unsigned int key_lifetime) #ifdef SSL_MODE_RELEASE_BUFFERS SSL_CTX_set_mode(result->ctx, SSL_MODE_RELEASE_BUFFERS); #endif - if (cert && !SSL_CTX_use_certificate(result->ctx,cert)) - goto error; - X509_free(cert); /* We just added a reference to cert. */ - cert=NULL; - if (idcert) { - X509_STORE *s = SSL_CTX_get_cert_store(result->ctx); - tor_assert(s); - X509_STORE_add_cert(s, idcert); - X509_free(idcert); /* The context now owns the reference to idcert */ - idcert = NULL; + if (! is_client) { + if (cert && !SSL_CTX_use_certificate(result->ctx,cert)) + goto error; + X509_free(cert); /* We just added a reference to cert. */ + cert=NULL; + if (idcert) { + X509_STORE *s = SSL_CTX_get_cert_store(result->ctx); + tor_assert(s); + X509_STORE_add_cert(s, idcert); + X509_free(idcert); /* The context now owns the reference to idcert */ + idcert = NULL; + } } SSL_CTX_set_session_cache_mode(result->ctx, SSL_SESS_CACHE_OFF); - tor_assert(rsa); - if (!(pkey = _crypto_pk_env_get_evp_pkey(rsa,1))) - goto error; - if (!SSL_CTX_use_PrivateKey(result->ctx, pkey)) - goto error; - EVP_PKEY_free(pkey); - pkey = NULL; - if (!SSL_CTX_check_private_key(result->ctx)) - goto error; + if (!is_client) { + tor_assert(rsa); + if (!(pkey = _crypto_pk_env_get_evp_pkey(rsa,1))) + goto error; + if (!SSL_CTX_use_PrivateKey(result->ctx, pkey)) + goto error; + EVP_PKEY_free(pkey); + pkey = NULL; + if (!SSL_CTX_check_private_key(result->ctx)) + goto error; + } { crypto_dh_env_t *dh = crypto_dh_new(DH_TYPE_TLS); SSL_CTX_set_tmp_dh(result->ctx, _crypto_dh_env_get_dh(dh));

1 0