diff options
Diffstat (limited to 'meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/0014-EAP-pwd-Check-element-x-y-coordinates-explicitly.patch')
| -rw-r--r-- | meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/0014-EAP-pwd-Check-element-x-y-coordinates-explicitly.patch | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/0014-EAP-pwd-Check-element-x-y-coordinates-explicitly.patch b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/0014-EAP-pwd-Check-element-x-y-coordinates-explicitly.patch new file mode 100644 index 0000000000..e944ef110f --- /dev/null +++ b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/0014-EAP-pwd-Check-element-x-y-coordinates-explicitly.patch @@ -0,0 +1,335 @@ +From 16d4f1069118aa19bfce013493e1ac5783f92f1d Mon Sep 17 00:00:00 2001 +From: Jouni Malinen <jouni@codeaurora.org> +Date: Fri, 5 Apr 2019 02:12:50 +0300 +Subject: [PATCH 14/14] EAP-pwd: Check element x,y coordinates explicitly + +This adds an explicit check for 0 < x,y < prime based on RFC 5931, +2.8.5.2.2 requirement. The earlier checks might have covered this +implicitly, but it is safer to avoid any dependency on implicit checks +and specific crypto library behavior. (CVE-2019-9498 and CVE-2019-9499) + +Furthermore, this moves the EAP-pwd element and scalar parsing and +validation steps into shared helper functions so that there is no need +to maintain two separate copies of this common functionality between the +server and peer implementations. + +Signed-off-by: Jouni Malinen <jouni@codeaurora.org> +Signed-off-by: Adrian Bunk <bunk@stusta.de> +Upstream-Status: Backport +CVE: CVE-2019-9498 +CVE: CVE-2019-9499 +--- + src/eap_common/eap_pwd_common.c | 106 ++++++++++++++++++++++++++++++++++++++++ + src/eap_common/eap_pwd_common.h | 3 ++ + src/eap_peer/eap_pwd.c | 45 ++--------------- + src/eap_server/eap_server_pwd.c | 45 ++--------------- + 4 files changed, 117 insertions(+), 82 deletions(-) + +diff --git a/src/eap_common/eap_pwd_common.c b/src/eap_common/eap_pwd_common.c +index e49aaf8..c28b56d 100644 +--- a/src/eap_common/eap_pwd_common.c ++++ b/src/eap_common/eap_pwd_common.c +@@ -428,3 +428,109 @@ int compute_keys(EAP_PWD_group *grp, const struct crypto_bignum *k, + + return 1; + } ++ ++ ++static int eap_pwd_element_coord_ok(const struct crypto_bignum *prime, ++ const u8 *buf, size_t len) ++{ ++ struct crypto_bignum *val; ++ int ok = 1; ++ ++ val = crypto_bignum_init_set(buf, len); ++ if (!val || crypto_bignum_is_zero(val) || ++ crypto_bignum_cmp(val, prime) >= 0) ++ ok = 0; ++ crypto_bignum_deinit(val, 0); ++ return ok; ++} ++ ++ ++struct crypto_ec_point * eap_pwd_get_element(EAP_PWD_group *group, ++ const u8 *buf) ++{ ++ struct crypto_ec_point *element; ++ const struct crypto_bignum *prime; ++ size_t prime_len; ++ struct crypto_bignum *cofactor = NULL; ++ ++ prime = crypto_ec_get_prime(group->group); ++ prime_len = crypto_ec_prime_len(group->group); ++ ++ /* RFC 5931, 2.8.5.2.2: 0 < x,y < p */ ++ if (!eap_pwd_element_coord_ok(prime, buf, prime_len) || ++ !eap_pwd_element_coord_ok(prime, buf + prime_len, prime_len)) { ++ wpa_printf(MSG_INFO, "EAP-pwd: Invalid coordinate in element"); ++ return NULL; ++ } ++ ++ element = crypto_ec_point_from_bin(group->group, buf); ++ if (!element) { ++ wpa_printf(MSG_INFO, "EAP-pwd: EC point from element failed"); ++ return NULL; ++ } ++ ++ /* RFC 5931, 2.8.5.2.2: on curve and not the point at infinity */ ++ if (!crypto_ec_point_is_on_curve(group->group, element) || ++ crypto_ec_point_is_at_infinity(group->group, element)) { ++ wpa_printf(MSG_INFO, "EAP-pwd: Invalid element"); ++ goto fail; ++ } ++ ++ cofactor = crypto_bignum_init(); ++ if (!cofactor || crypto_ec_cofactor(group->group, cofactor) < 0) { ++ wpa_printf(MSG_INFO, ++ "EAP-pwd: Unable to get cofactor for curve"); ++ goto fail; ++ } ++ ++ if (!crypto_bignum_is_one(cofactor)) { ++ struct crypto_ec_point *point; ++ int ok = 1; ++ ++ /* check to ensure peer's element is not in a small sub-group */ ++ point = crypto_ec_point_init(group->group); ++ if (!point || ++ crypto_ec_point_mul(group->group, element, ++ cofactor, point) != 0 || ++ crypto_ec_point_is_at_infinity(group->group, point)) ++ ok = 0; ++ crypto_ec_point_deinit(point, 0); ++ ++ if (!ok) { ++ wpa_printf(MSG_INFO, ++ "EAP-pwd: Small sub-group check on peer element failed"); ++ goto fail; ++ } ++ } ++ ++out: ++ crypto_bignum_deinit(cofactor, 0); ++ return element; ++fail: ++ crypto_ec_point_deinit(element, 0); ++ element = NULL; ++ goto out; ++} ++ ++ ++struct crypto_bignum * eap_pwd_get_scalar(EAP_PWD_group *group, const u8 *buf) ++{ ++ struct crypto_bignum *scalar; ++ const struct crypto_bignum *order; ++ size_t order_len; ++ ++ order = crypto_ec_get_order(group->group); ++ order_len = crypto_ec_order_len(group->group); ++ ++ /* RFC 5931, 2.8.5.2: 1 < scalar < r */ ++ scalar = crypto_bignum_init_set(buf, order_len); ++ if (!scalar || crypto_bignum_is_zero(scalar) || ++ crypto_bignum_is_one(scalar) || ++ crypto_bignum_cmp(scalar, order) >= 0) { ++ wpa_printf(MSG_INFO, "EAP-pwd: received scalar is invalid"); ++ crypto_bignum_deinit(scalar, 0); ++ scalar = NULL; ++ } ++ ++ return scalar; ++} +diff --git a/src/eap_common/eap_pwd_common.h b/src/eap_common/eap_pwd_common.h +index 6b07cf8..2387e59 100644 +--- a/src/eap_common/eap_pwd_common.h ++++ b/src/eap_common/eap_pwd_common.h +@@ -67,5 +67,8 @@ int compute_keys(EAP_PWD_group *grp, const struct crypto_bignum *k, + struct crypto_hash * eap_pwd_h_init(void); + void eap_pwd_h_update(struct crypto_hash *hash, const u8 *data, size_t len); + void eap_pwd_h_final(struct crypto_hash *hash, u8 *digest); ++struct crypto_ec_point * eap_pwd_get_element(EAP_PWD_group *group, ++ const u8 *buf); ++struct crypto_bignum * eap_pwd_get_scalar(EAP_PWD_group *group, const u8 *buf); + + #endif /* EAP_PWD_COMMON_H */ +diff --git a/src/eap_peer/eap_pwd.c b/src/eap_peer/eap_pwd.c +index 5a05e54..f37b974 100644 +--- a/src/eap_peer/eap_pwd.c ++++ b/src/eap_peer/eap_pwd.c +@@ -308,7 +308,7 @@ eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data, + const struct wpabuf *reqData, + const u8 *payload, size_t payload_len) + { +- struct crypto_ec_point *K = NULL, *point = NULL; ++ struct crypto_ec_point *K = NULL; + struct crypto_bignum *mask = NULL, *cofactor = NULL; + const u8 *ptr = payload; + u8 *scalar = NULL, *element = NULL; +@@ -572,63 +572,27 @@ eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data, + /* process the request */ + data->k = crypto_bignum_init(); + K = crypto_ec_point_init(data->grp->group); +- point = crypto_ec_point_init(data->grp->group); +- if (!data->k || !K || !point) { ++ if (!data->k || !K) { + wpa_printf(MSG_INFO, "EAP-PWD (peer): peer data allocation " + "fail"); + goto fin; + } + + /* element, x then y, followed by scalar */ +- data->server_element = crypto_ec_point_from_bin(data->grp->group, ptr); ++ data->server_element = eap_pwd_get_element(data->grp, ptr); + if (!data->server_element) { + wpa_printf(MSG_INFO, "EAP-PWD (peer): setting peer element " + "fail"); + goto fin; + } + ptr += prime_len * 2; +- data->server_scalar = crypto_bignum_init_set(ptr, order_len); ++ data->server_scalar = eap_pwd_get_scalar(data->grp, ptr); + if (!data->server_scalar) { + wpa_printf(MSG_INFO, + "EAP-PWD (peer): setting peer scalar fail"); + goto fin; + } + +- /* verify received scalar */ +- if (crypto_bignum_is_zero(data->server_scalar) || +- crypto_bignum_is_one(data->server_scalar) || +- crypto_bignum_cmp(data->server_scalar, +- crypto_ec_get_order(data->grp->group)) >= 0) { +- wpa_printf(MSG_INFO, +- "EAP-PWD (peer): received scalar is invalid"); +- goto fin; +- } +- +- /* verify received element */ +- if (!crypto_ec_point_is_on_curve(data->grp->group, +- data->server_element) || +- crypto_ec_point_is_at_infinity(data->grp->group, +- data->server_element)) { +- wpa_printf(MSG_INFO, +- "EAP-PWD (peer): received element is invalid"); +- goto fin; +- } +- +- /* check to ensure server's element is not in a small sub-group */ +- if (!crypto_bignum_is_one(cofactor)) { +- if (crypto_ec_point_mul(data->grp->group, data->server_element, +- cofactor, point) < 0) { +- wpa_printf(MSG_INFO, "EAP-PWD (peer): cannot multiply " +- "server element by order!\n"); +- goto fin; +- } +- if (crypto_ec_point_is_at_infinity(data->grp->group, point)) { +- wpa_printf(MSG_INFO, "EAP-PWD (peer): server element " +- "is at infinity!\n"); +- goto fin; +- } +- } +- + /* compute the shared key, k */ + if (crypto_ec_point_mul(data->grp->group, data->grp->pwe, + data->server_scalar, K) < 0 || +@@ -702,7 +666,6 @@ fin: + crypto_bignum_deinit(mask, 1); + crypto_bignum_deinit(cofactor, 1); + crypto_ec_point_deinit(K, 1); +- crypto_ec_point_deinit(point, 1); + if (data->outbuf == NULL) + eap_pwd_state(data, FAILURE); + else +diff --git a/src/eap_server/eap_server_pwd.c b/src/eap_server/eap_server_pwd.c +index 16057e9..f6c75cf 100644 +--- a/src/eap_server/eap_server_pwd.c ++++ b/src/eap_server/eap_server_pwd.c +@@ -669,7 +669,7 @@ eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, + { + const u8 *ptr; + struct crypto_bignum *cofactor = NULL; +- struct crypto_ec_point *K = NULL, *point = NULL; ++ struct crypto_ec_point *K = NULL; + int res = 0; + size_t prime_len, order_len; + +@@ -688,9 +688,8 @@ eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, + + data->k = crypto_bignum_init(); + cofactor = crypto_bignum_init(); +- point = crypto_ec_point_init(data->grp->group); + K = crypto_ec_point_init(data->grp->group); +- if (!data->k || !cofactor || !point || !K) { ++ if (!data->k || !cofactor || !K) { + wpa_printf(MSG_INFO, "EAP-PWD (server): peer data allocation " + "fail"); + goto fin; +@@ -704,55 +703,20 @@ eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, + + /* element, x then y, followed by scalar */ + ptr = payload; +- data->peer_element = crypto_ec_point_from_bin(data->grp->group, ptr); ++ data->peer_element = eap_pwd_get_element(data->grp, ptr); + if (!data->peer_element) { + wpa_printf(MSG_INFO, "EAP-PWD (server): setting peer element " + "fail"); + goto fin; + } + ptr += prime_len * 2; +- data->peer_scalar = crypto_bignum_init_set(ptr, order_len); ++ data->peer_scalar = eap_pwd_get_scalar(data->grp, ptr); + if (!data->peer_scalar) { + wpa_printf(MSG_INFO, "EAP-PWD (server): peer data allocation " + "fail"); + goto fin; + } + +- /* verify received scalar */ +- if (crypto_bignum_is_zero(data->peer_scalar) || +- crypto_bignum_is_one(data->peer_scalar) || +- crypto_bignum_cmp(data->peer_scalar, +- crypto_ec_get_order(data->grp->group)) >= 0) { +- wpa_printf(MSG_INFO, +- "EAP-PWD (server): received scalar is invalid"); +- goto fin; +- } +- +- /* verify received element */ +- if (!crypto_ec_point_is_on_curve(data->grp->group, +- data->peer_element) || +- crypto_ec_point_is_at_infinity(data->grp->group, +- data->peer_element)) { +- wpa_printf(MSG_INFO, +- "EAP-PWD (server): received element is invalid"); +- goto fin; +- } +- +- /* check to ensure peer's element is not in a small sub-group */ +- if (!crypto_bignum_is_one(cofactor)) { +- if (crypto_ec_point_mul(data->grp->group, data->peer_element, +- cofactor, point) != 0) { +- wpa_printf(MSG_INFO, "EAP-PWD (server): cannot " +- "multiply peer element by order"); +- goto fin; +- } +- if (crypto_ec_point_is_at_infinity(data->grp->group, point)) { +- wpa_printf(MSG_INFO, "EAP-PWD (server): peer element " +- "is at infinity!\n"); +- goto fin; +- } +- } +- + /* detect reflection attacks */ + if (crypto_bignum_cmp(data->my_scalar, data->peer_scalar) == 0 || + crypto_ec_point_cmp(data->grp->group, data->my_element, +@@ -804,7 +768,6 @@ eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, + + fin: + crypto_ec_point_deinit(K, 1); +- crypto_ec_point_deinit(point, 1); + crypto_bignum_deinit(cofactor, 1); + + if (res) +-- +2.7.4 + |