EAP-PAX server: Check hash function results

While these local failure cases are mostly theoretical, it is better to
check for the errors explicitly.

Signed-off-by: Jouni Malinen <j@w1.fi>

diff --git a/src/eap_server/eap_server_pax.c b/src/eap_server/eap_server_pax.c
index 3257789695cdeaff1873396e96210f4d94fcea75..8ef90c97a65a8aba7bf4fe17601db8d7584d62f4 100644 (file)
--- a/src/eap_server/eap_server_pax.c
+++ b/src/eap_server/eap_server_pax.c
@@ -107,9 +107,14 @@ static struct wpabuf * eap_pax_build_std_1(struct eap_sm *sm,
                    data->rand.r.x, EAP_PAX_RAND_LEN);
 
        pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
-       eap_pax_mac(data->mac_id, (u8 *) "", 0,
-                   wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
-                   NULL, 0, NULL, 0, pos);
+       if (eap_pax_mac(data->mac_id, (u8 *) "", 0,
+                       wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
+                       NULL, 0, NULL, 0, pos) < 0) {
+               wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate ICV");
+               data->state = FAILURE;
+               wpabuf_free(req);
+               return NULL;
+       }
        wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
 
        return req;
@@ -144,18 +149,28 @@ static struct wpabuf * eap_pax_build_std_3(struct eap_sm *sm,
 
        wpabuf_put_be16(req, EAP_PAX_MAC_LEN);
        pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
-       eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
-                   data->rand.r.y, EAP_PAX_RAND_LEN,
-                   (u8 *) data->cid, data->cid_len, NULL, 0, pos);
+       if (eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
+                       data->rand.r.y, EAP_PAX_RAND_LEN,
+                       (u8 *) data->cid, data->cid_len, NULL, 0, pos) < 0) {
+               wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate MAC");
+               data->state = FAILURE;
+               wpabuf_free(req);
+               return NULL;
+       }
        wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
                    pos, EAP_PAX_MAC_LEN);
 
        /* Optional ADE could be added here, if needed */
 
        pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
-       eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
-                   wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
-                   NULL, 0, NULL, 0, pos);
+       if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
+                       wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
+                       NULL, 0, NULL, 0, pos) < 0) {
+               wpa_printf(MSG_ERROR, "EAP-PAX: Failed to calculate ICV");
+               data->state = FAILURE;
+               wpabuf_free(req);
+               return NULL;
+       }
        wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
 
        return req;
@@ -264,11 +279,11 @@ static Boolean eap_pax_check(struct eap_sm *sm, void *priv,
                }
                icv = wpabuf_mhead_u8(respData) + mlen - EAP_PAX_ICV_LEN;
                wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
-               eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
-                           wpabuf_mhead(respData),
-                           wpabuf_len(respData) - EAP_PAX_ICV_LEN,
-                           NULL, 0, NULL, 0, icvbuf);
-               if (os_memcmp_const(icvbuf, icv, EAP_PAX_ICV_LEN) != 0) {
+               if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
+                               wpabuf_mhead(respData),
+                               wpabuf_len(respData) - EAP_PAX_ICV_LEN,
+                               NULL, 0, NULL, 0, icvbuf) < 0 ||
+                   os_memcmp_const(icvbuf, icv, EAP_PAX_ICV_LEN) != 0) {
                        wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV");
                        wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
                                    icvbuf, EAP_PAX_ICV_LEN);
@@ -395,11 +410,11 @@ static void eap_pax_process_std_2(struct eap_sm *sm,
        }
        data->keys_set = 1;
 
-       eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
-                   data->rand.r.x, EAP_PAX_RAND_LEN,
-                   data->rand.r.y, EAP_PAX_RAND_LEN,
-                   (u8 *) data->cid, data->cid_len, mac);
-       if (os_memcmp_const(mac, pos, EAP_PAX_MAC_LEN) != 0) {
+       if (eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
+                       data->rand.r.x, EAP_PAX_RAND_LEN,
+                       data->rand.r.y, EAP_PAX_RAND_LEN,
+                       (u8 *) data->cid, data->cid_len, mac) < 0 ||
+           os_memcmp_const(mac, pos, EAP_PAX_MAC_LEN) != 0) {
                wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(A, B, CID) in "
                           "PAX_STD-2");
                wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected MAC_CK(A, B, CID)",
@@ -417,11 +432,11 @@ static void eap_pax_process_std_2(struct eap_sm *sm,
                return;
        }
        wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
-       eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
-                   wpabuf_head(respData),
-                   wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0,
-                   icvbuf);
-       if (os_memcmp_const(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) {
+       if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
+                       wpabuf_head(respData),
+                       wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0,
+                       NULL, 0, icvbuf) < 0 ||
+           os_memcmp_const(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) {
                wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV in PAX_STD-2");
                wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
                            icvbuf, EAP_PAX_ICV_LEN);