From 5b8a3601ebff7a0cdfaa50d7a0b5e384a7e2514c Mon Sep 17 00:00:00 2001 From: Vivek Kumbhar Date: Wed, 8 Mar 2023 12:14:30 +0530 Subject: gnutls: fix CVE-2023-0361 timing side-channel in the TLS RSA key exchange code Remove branching that depends on secret data. since the `ok` variable isn't used any more, we can remove all code used to calculate it Signed-off-by: Vivek Kumbhar Signed-off-by: Steve Sakoman --- .../gnutls/gnutls/CVE-2023-0361.patch | 85 ++++++++++++++++++++++ meta/recipes-support/gnutls/gnutls_3.6.14.bb | 1 + 2 files changed, 86 insertions(+) create mode 100644 meta/recipes-support/gnutls/gnutls/CVE-2023-0361.patch diff --git a/meta/recipes-support/gnutls/gnutls/CVE-2023-0361.patch b/meta/recipes-support/gnutls/gnutls/CVE-2023-0361.patch new file mode 100644 index 0000000000..943f4ca704 --- /dev/null +++ b/meta/recipes-support/gnutls/gnutls/CVE-2023-0361.patch @@ -0,0 +1,85 @@ +From 80a6ce8ddb02477cd724cd5b2944791aaddb702a Mon Sep 17 00:00:00 2001 +From: Alexander Sosedkin +Date: Tue, 9 Aug 2022 16:05:53 +0200 +Subject: [PATCH] auth/rsa: side-step potential side-channel + +Signed-off-by: Alexander Sosedkin +Signed-off-by: Hubert Kario +Tested-by: Hubert Kario +Upstream-Status: Backport [https://gitlab.com/gnutls/gnutls/-/commit/80a6ce8ddb02477cd724cd5b2944791aaddb702a + https://gitlab.com/gnutls/gnutls/-/commit/4b7ff428291c7ed77c6d2635577c83a43bbae558] +CVE: CVE-2023-0361 +Signed-off-by: Vivek Kumbhar +--- + lib/auth/rsa.c | 30 +++--------------------------- + 1 file changed, 3 insertions(+), 27 deletions(-) + +diff --git a/lib/auth/rsa.c b/lib/auth/rsa.c +index 8108ee8..858701f 100644 +--- a/lib/auth/rsa.c ++++ b/lib/auth/rsa.c +@@ -155,13 +155,10 @@ static int + proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, + size_t _data_size) + { +- const char attack_error[] = "auth_rsa: Possible PKCS #1 attack\n"; + gnutls_datum_t ciphertext; + int ret, dsize; + ssize_t data_size = _data_size; + volatile uint8_t ver_maj, ver_min; +- volatile uint8_t check_ver_min; +- volatile uint32_t ok; + + #ifdef ENABLE_SSL3 + if (get_num_version(session) == GNUTLS_SSL3) { +@@ -187,7 +184,6 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, + + ver_maj = _gnutls_get_adv_version_major(session); + ver_min = _gnutls_get_adv_version_minor(session); +- check_ver_min = (session->internals.allow_wrong_pms == 0); + + session->key.key.data = gnutls_malloc(GNUTLS_MASTER_SIZE); + if (session->key.key.data == NULL) { +@@ -206,10 +202,9 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, + return ret; + } + +- ret = +- gnutls_privkey_decrypt_data2(session->internals.selected_key, +- 0, &ciphertext, session->key.key.data, +- session->key.key.size); ++ gnutls_privkey_decrypt_data2(session->internals.selected_key, ++ 0, &ciphertext, session->key.key.data, ++ session->key.key.size); + /* After this point, any conditional on failure that cause differences + * in execution may create a timing or cache access pattern side + * channel that can be used as an oracle, so treat very carefully */ +@@ -225,25 +220,6 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, + * Vlastimil Klima, Ondej Pokorny and Tomas Rosa. + */ + +- /* ok is 0 in case of error and 1 in case of success. */ +- +- /* if ret < 0 */ +- ok = CONSTCHECK_EQUAL(ret, 0); +- /* session->key.key.data[0] must equal ver_maj */ +- ok &= CONSTCHECK_EQUAL(session->key.key.data[0], ver_maj); +- /* if check_ver_min then session->key.key.data[1] must equal ver_min */ +- ok &= CONSTCHECK_NOT_EQUAL(check_ver_min, 0) & +- CONSTCHECK_EQUAL(session->key.key.data[1], ver_min); +- +- if (ok) { +- /* call logging function unconditionally so all branches are +- * indistinguishable for timing and cache access when debug +- * logging is disabled */ +- _gnutls_no_log("%s", attack_error); +- } else { +- _gnutls_debug_log("%s", attack_error); +- } +- + /* This is here to avoid the version check attack + * discussed above. + */ +-- +2.25.1 + diff --git a/meta/recipes-support/gnutls/gnutls_3.6.14.bb b/meta/recipes-support/gnutls/gnutls_3.6.14.bb index f1757871ce..0c3392d521 100644 --- a/meta/recipes-support/gnutls/gnutls_3.6.14.bb +++ b/meta/recipes-support/gnutls/gnutls_3.6.14.bb @@ -27,6 +27,7 @@ SRC_URI = "https://www.gnupg.org/ftp/gcrypt/gnutls/v${SHRT_VER}/gnutls-${PV}.tar file://CVE-2021-20232.patch \ file://CVE-2022-2509.patch \ file://CVE-2021-4209.patch \ + file://CVE-2023-0361.patch \ " SRC_URI[sha256sum] = "5630751adec7025b8ef955af4d141d00d252a985769f51b4059e5affa3d39d63" -- cgit 1.2.3-korg