Module Name: src
Committed By: christos
Date: Wed Apr 10 17:50:28 UTC 2019
Modified Files:
src/external/bsd/wpa/dist/src/eap_common: eap_pwd_common.c
eap_pwd_common.h
src/external/bsd/wpa/dist/src/eap_peer: eap_pwd.c
src/external/bsd/wpa/dist/src/eap_server: eap_server_pwd.c
Log Message:
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.
To generate a diff of this commit:
cvs rdiff -u -r1.1.1.6 -r1.2 \
src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c
cvs rdiff -u -r1.1.1.5 -r1.2 \
src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h
cvs rdiff -u -r1.7 -r1.8 src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c
cvs rdiff -u -r1.7 -r1.8 \
src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c
diff -u src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c:1.1.1.6 src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c:1.2
--- src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c:1.1.1.6 Fri Jan 4 14:29:19 2019
+++ src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.c Wed Apr 10 13:50:27 2019
@@ -416,3 +416,109 @@ int compute_keys(EAP_PWD_group *grp, con
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;
+}
Index: src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h
diff -u src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h:1.1.1.5 src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h:1.2
--- src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h:1.1.1.5 Fri Jan 4 14:29:19 2019
+++ src/external/bsd/wpa/dist/src/eap_common/eap_pwd_common.h Wed Apr 10 13:50:27 2019
@@ -67,5 +67,8 @@ int compute_keys(EAP_PWD_group *grp, con
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 */
Index: src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c
diff -u src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c:1.7 src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c:1.8
--- src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c:1.7 Wed Apr 10 13:49:59 2019
+++ src/external/bsd/wpa/dist/src/eap_peer/eap_pwd.c Wed Apr 10 13:50:28 2019
@@ -308,7 +308,7 @@ eap_pwd_perform_commit_exchange(struct e
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 e
/* 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
Index: src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c
diff -u src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c:1.7 src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c:1.8
--- src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c:1.7 Wed Apr 10 13:49:26 2019
+++ src/external/bsd/wpa/dist/src/eap_server/eap_server_pwd.c Wed Apr 10 13:50:28 2019
@@ -669,7 +669,7 @@ eap_pwd_process_commit_resp(struct eap_s
{
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_s
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_s
/* 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_s
fin:
crypto_ec_point_deinit(K, 1);
- crypto_ec_point_deinit(point, 1);
crypto_bignum_deinit(cofactor, 1);
if (res)
