SAE: Don't use potentially uninitialized keys

If SAE_CONFIG_PK is not defined and sae->pk isn't zero (which is
possible as it is controlled by the commit message status code),
sae_derive_keys() may end up deriving PMK and KCK from an
uninitialized array. Fix that.

Fixes: 6b9e99e571ee ("SAE-PK: Extend SAE functionality for AP validation")
Fixes: 20ccf97b3dc1 ("SAE-PK: AP functionality")
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>

diff --git a/src/common/sae.c b/src/common/sae.c
index 057e1ce3b19d8dd20ff6b2aa6e990791fbb789e6..372905db05e9529985684255f3ca0dfbe5b2b85d 100644 (file)
--- a/src/common/sae.c
+++ b/src/common/sae.c
@@ -1609,18 +1609,26 @@ static int sae_derive_keys(struct sae_data *sae, const u8 *k)
         * octets). */
        crypto_bignum_to_bin(tmp, val, sizeof(val), sae->tmp->order_len);
        wpa_hexdump(MSG_DEBUG, "SAE: PMKID", val, SAE_PMKID_LEN);
-       if (!sae->pk &&
-           sae_kdf_hash(hash_len, keyseed, "SAE KCK and PMK",
-                        val, sae->tmp->order_len,
-                        keys, hash_len + SAE_PMK_LEN) < 0)
-               goto fail;
+
 #ifdef CONFIG_SAE_PK
-       if (sae->pk &&
-           sae_kdf_hash(hash_len, keyseed, "SAE-PK keys",
+       if (sae->pk) {
+               if (sae_kdf_hash(hash_len, keyseed, "SAE-PK keys",
+                                val, sae->tmp->order_len,
+                                keys, 2 * hash_len + SAE_PMK_LEN) < 0)
+                       goto fail;
+       } else {
+               if (sae_kdf_hash(hash_len, keyseed, "SAE KCK and PMK",
+                                val, sae->tmp->order_len,
+                                keys, hash_len + SAE_PMK_LEN) < 0)
+                       goto fail;
+       }
+#else /* CONFIG_SAE_PK */
+       if (sae_kdf_hash(hash_len, keyseed, "SAE KCK and PMK",
                         val, sae->tmp->order_len,
-                        keys, 2 * hash_len + SAE_PMK_LEN) < 0)
+                        keys, hash_len + SAE_PMK_LEN) < 0)
                goto fail;
-#endif /* CONFIG_SAE_PK */
+#endif /* !CONFIG_SAE_PK */
+
        forced_memzero(keyseed, sizeof(keyseed));
        os_memcpy(sae->tmp->kck, keys, hash_len);
        sae->tmp->kck_len = hash_len;