December 2017 - tor-commits - lists.torproject.org

[tor/maint-0.3.2] Merge branch 'trove-2017-011_025' into maint-0.2.5
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 08ce39fb0fd50ab0da4201201fa07e7776cb09e7 Merge: a6a0c7a4e 1880a6a88 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 12:06:17 2017 -0500 Merge branch 'trove-2017-011_025' into maint-0.2.5 changes/trove-2017-011 | 8 ++++++++ src/common/crypto.c | 16 +++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-)

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[tor/maint-0.3.2] Guard: Don't pick ourselves as a possible Guard
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 91cee3c9e73aba089804cd88305115fc3ab1f76c Author: David Goulet <dgoulet(a)torproject.org> Date: Tue Nov 28 19:09:13 2017 -0500 Guard: Don't pick ourselves as a possible Guard TROVE-2017-12. Severity: Medium Thankfully, tor will close any circuits that we try to extend to ourselves so this is not problematic but annoying. Part of #21534. --- changes/trove-2017-012-part2 | 5 +++++ src/or/entrynodes.c | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/changes/trove-2017-012-part2 b/changes/trove-2017-012-part2 new file mode 100644 index 000000000..ed994c5b0 --- /dev/null +++ b/changes/trove-2017-012-part2 @@ -0,0 +1,5 @@ + o Major bugfixes (security, relay): + - When running as a relay, make sure that we never ever choose ourselves + as a guard. Previously, this was possible. Fixes part of bug 21534; + bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 + and CVE-2017-8822. diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index d762afdcf..0109da8e0 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -740,7 +740,8 @@ node_is_possible_guard(const node_t *node) node->is_stable && node->is_fast && node->is_valid && - node_is_dir(node)); + node_is_dir(node) && + !router_digest_is_me(node->identity)); } /**

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[tor/maint-0.3.2] hs-v2: Remove any expiring intro from the retry list
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 3030741b5d24e9ae36e6d72c6a8c7d035fde9d2a Author: David Goulet <dgoulet(a)torproject.org> Date: Tue Nov 21 10:16:08 2017 -0500 hs-v2: Remove any expiring intro from the retry list TROVE-2017-13. Severity: High. In the unlikely case that a hidden service could be missing intro circuit(s), that it didn't have enough directory information to open new circuits and that an intro point was about to expire, a use-after-free is possible because of the intro point object being both in the retry list and expiring list at the same time. The intro object would get freed after the circuit failed to open and then access a second time when cleaned up from the expiring list. Fixes #24313 --- changes/bug24313 | 5 +++++ src/or/rendservice.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/changes/bug24313 b/changes/bug24313 new file mode 100644 index 000000000..b927ec3ba --- /dev/null +++ b/changes/bug24313 @@ -0,0 +1,5 @@ + o Major bugfixes (security, hidden service v2): + - Fix a use-after-free error that could crash v2 Tor hidden services + when it failed to open circuits while expiring introductions + points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This + issue is also tracked as TROVE-2017-013 and CVE-2017-8823. diff --git a/src/or/rendservice.c b/src/or/rendservice.c index 0a5b5efd5..cbf998136 100644 --- a/src/or/rendservice.c +++ b/src/or/rendservice.c @@ -3444,6 +3444,10 @@ remove_invalid_intro_points(rend_service_t *service, log_info(LD_REND, "Expiring %s as intro point for %s.", safe_str_client(extend_info_describe(intro->extend_info)), safe_str_client(service->service_id)); + /* We might have put it in the retry list if so, undo. */ + if (retry_nodes) { + smartlist_remove(retry_nodes, intro); + } smartlist_add(service->expiring_nodes, intro); SMARTLIST_DEL_CURRENT(service->intro_nodes, intro); /* Intro point is expired, we need a new one thus don't consider it

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[tor/maint-0.3.2] Fix changes file
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 75509dc82778a3bb866dca0fa86ae3e179ad78fa Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 11:52:40 2017 -0500 Fix changes file --- changes/trove-2017-009 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/changes/trove-2017-009 b/changes/trove-2017-009 index 512d18c29..166a5faec 100644 --- a/changes/trove-2017-009 +++ b/changes/trove-2017-009 @@ -1,4 +1,4 @@ - o Major fixes (security): + o Major bugfixes (security): - When checking for replays in the INTRODUCE1 cell data for a (legacy) hiddden service, correctly detect replays in the RSA-encrypted part of the cell. We were previously checking for replays on the entire cell,

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[tor/maint-0.3.2] Merge branch 'maint-0.2.8' into maint-0.2.9
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 7e2b012b46a4ade2818e47be15d76255cf6f121e Merge: 52d7af631 ba4a9cf0c Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 12:07:59 2017 -0500 Merge branch 'maint-0.2.8' into maint-0.2.9 changes/bug24313 | 5 +++++ changes/trove-2017-009 | 10 ++++++++++ changes/trove-2017-011 | 8 ++++++++ changes/trove-2017-012-part1 | 6 ++++++ src/common/crypto.c | 16 +++++++++++++--- src/or/rendservice.c | 8 +++++++- src/or/routerlist.c | 5 ++++- 7 files changed, 53 insertions(+), 5 deletions(-)

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[tor/maint-0.3.2] Merge branch 'trove-2017-009_025' into maint-0.2.5
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit a6a0c7a4ecc22a744b123a47d466963f6023a11f Merge: 831d3b794 75509dc82 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 12:05:59 2017 -0500 Merge branch 'trove-2017-009_025' into maint-0.2.5 changes/trove-2017-009 | 10 ++++++++++ src/or/rendservice.c | 4 +++- 2 files changed, 13 insertions(+), 1 deletion(-)

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[tor/maint-0.3.2] Merge branch 'maint-0.2.9' into maint-0.3.0
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 5fc0587c040339357bc3fc37f1b5474f1c3d1a33 Merge: d459c08b7 7e2b012b4 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 12:07:59 2017 -0500 Merge branch 'maint-0.2.9' into maint-0.3.0 changes/bug24313 | 5 +++++ changes/trove-2017-009 | 10 ++++++++++ changes/trove-2017-010 | 6 ++++++ changes/trove-2017-011 | 8 ++++++++ changes/trove-2017-012-part1 | 6 ++++++ src/common/crypto.c | 16 +++++++++++++--- src/or/protover.c | 5 +++++ src/or/rendservice.c | 8 +++++++- src/or/routerlist.c | 5 ++++- 9 files changed, 64 insertions(+), 5 deletions(-)

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[tor/master] Merge branch 'trove-2017-011_025' into maint-0.2.5
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 08ce39fb0fd50ab0da4201201fa07e7776cb09e7 Merge: a6a0c7a4e 1880a6a88 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Nov 30 12:06:17 2017 -0500 Merge branch 'trove-2017-011_025' into maint-0.2.5 changes/trove-2017-011 | 8 ++++++++ src/common/crypto.c | 16 +++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-)

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[tor/master] Fix length of replaycache-checked data.
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 2834cc9c18230c36278ffa94a252abeb91b6cff9 Author: Nick Mathewson <nickm(a)torproject.org> Date: Sat Nov 11 13:40:21 2017 -0500 Fix length of replaycache-checked data. This is a regression; we should have been checking only the public-key encrypted portion. Fixes bug 24244, TROVE-2017-009, and CVE-2017-8819. --- changes/trove-2017-009 | 10 ++++++++++ src/or/rendservice.c | 4 +++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/changes/trove-2017-009 b/changes/trove-2017-009 new file mode 100644 index 000000000..512d18c29 --- /dev/null +++ b/changes/trove-2017-009 @@ -0,0 +1,10 @@ + o Major fixes (security): + - When checking for replays in the INTRODUCE1 cell data for a (legacy) + hiddden service, correctly detect replays in the RSA-encrypted part of + the cell. We were previously checking for replays on the entire cell, + but those can be circumvented due to the malleability of Tor's legacy + hybrid encryption. This fix helps prevent a traffic confirmation + attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also + tracked as TROVE-2017-009 and CVE-2017-8819. + + diff --git a/src/or/rendservice.c b/src/or/rendservice.c index d958de9df..ba8891ead 100644 --- a/src/or/rendservice.c +++ b/src/or/rendservice.c @@ -1162,6 +1162,7 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request, time_t now = time(NULL); time_t elapsed; int replay; + size_t keylen; /* Do some initial validation and logging before we parse the cell */ if (circuit->base_.purpose != CIRCUIT_PURPOSE_S_INTRO) { @@ -1245,9 +1246,10 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request, } /* check for replay of PK-encrypted portion. */ + keylen = crypto_pk_keysize(intro_key); replay = replaycache_add_test_and_elapsed( intro_point->accepted_intro_rsa_parts, - parsed_req->ciphertext, parsed_req->ciphertext_len, + parsed_req->ciphertext, MIN(parsed_req->ciphertext_len, keylen), &elapsed); if (replay) {

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[tor/master] Avoid asking for passphrase on junky PEM input
by nickm＠torproject.org 01 Dec '17

01 Dec '17

commit 1880a6a88e240556a8e6b169f1160aa8220ab0ec Author: Nick Mathewson <nickm(a)torproject.org> Date: Sat Nov 11 14:21:37 2017 -0500 Avoid asking for passphrase on junky PEM input Fixes bug 24246 and TROVE-2017-011. This bug is so old, it's in Matej's code. Seems to have been introduced with e01522bbed6eea. --- changes/trove-2017-011 | 8 ++++++++ src/common/crypto.c | 16 +++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/changes/trove-2017-011 b/changes/trove-2017-011 new file mode 100644 index 000000000..82d20d9e7 --- /dev/null +++ b/changes/trove-2017-011 @@ -0,0 +1,8 @@ + o Major bugfixes (security): + - Fix a denial of service bug where an attacker could use a malformed + directory object to cause a Tor instance to pause while OpenSSL would + try to read a passphrase from the terminal. (If the terminal was not + available, tor would continue running.) Fixes bug 24246; bugfix on + every version of Tor. Also tracked as TROVE-2017-011 and + CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720. + diff --git a/src/common/crypto.c b/src/common/crypto.c index f7362765d..8d816652d 100644 --- a/src/common/crypto.c +++ b/src/common/crypto.c @@ -592,11 +592,21 @@ crypto_pk_generate_key_with_bits(crypto_pk_t *env, int bits) return 0; } +/** A PEM callback that always reports a failure to get a password */ +static int +pem_no_password_cb(char *buf, int size, int rwflag, void *u) +{ + (void)buf; + (void)size; + (void)rwflag; + (void)u; + return 0; +} + /** Read a PEM-encoded private key from the len-byte string s * into env. Return 0 on success, -1 on failure. If len is -1, * the string is nul-terminated. */ -/* Used here, and used for testing. */ int crypto_pk_read_private_key_from_string(crypto_pk_t *env, const char *s, ssize_t len) @@ -615,7 +625,7 @@ crypto_pk_read_private_key_from_string(crypto_pk_t *env, if (env->key) RSA_free(env->key); - env->key = PEM_read_bio_RSAPrivateKey(b,NULL,NULL,NULL); + env->key = PEM_read_bio_RSAPrivateKey(b,NULL,pem_no_password_cb,NULL); BIO_free(b); @@ -747,7 +757,7 @@ crypto_pk_read_public_key_from_string(crypto_pk_t *env, const char *src, if (env->key) RSA_free(env->key); - env->key = PEM_read_bio_RSAPublicKey(b, NULL, NULL, NULL); + env->key = PEM_read_bio_RSAPublicKey(b, NULL, pem_no_password_cb, NULL); BIO_free(b); if (!env->key) { crypto_log_errors(LOG_WARN, "reading public key from string");

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