SAE: Return result from confirm CN() operation to the caller

These functions could fail in theory, so report the result to the
caller.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/src/common/sae.c b/src/common/sae.c
index 08fdbfd181732d18fe5bffa44865af7a46419a35..3960914072807bad4962f5326dbcdf16865611e9 100644 (file)
--- a/src/common/sae.c
+++ b/src/common/sae.c
@@ -1157,12 +1157,12 @@ u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
 }
 
 
-static void sae_cn_confirm(struct sae_data *sae, const u8 *sc,
-                          const struct crypto_bignum *scalar1,
-                          const u8 *element1, size_t element1_len,
-                          const struct crypto_bignum *scalar2,
-                          const u8 *element2, size_t element2_len,
-                          u8 *confirm)
+static int sae_cn_confirm(struct sae_data *sae, const u8 *sc,
+                         const struct crypto_bignum *scalar1,
+                         const u8 *element1, size_t element1_len,
+                         const struct crypto_bignum *scalar2,
+                         const u8 *element2, size_t element2_len,
+                         u8 *confirm)
 {
        const u8 *addr[5];
        size_t len[5];
@@ -1176,62 +1176,68 @@ static void sae_cn_confirm(struct sae_data *sae, const u8 *sc,
         * verifier = CN(KCK, peer-send-confirm, peer-commit-scalar,
         *               PEER-COMMIT-ELEMENT, commit-scalar, COMMIT-ELEMENT)
         */
+       if (crypto_bignum_to_bin(scalar1, scalar_b1, sizeof(scalar_b1),
+                                sae->tmp->prime_len) < 0 ||
+           crypto_bignum_to_bin(scalar2, scalar_b2, sizeof(scalar_b2),
+                                sae->tmp->prime_len) < 0)
+               return -1;
        addr[0] = sc;
        len[0] = 2;
-       crypto_bignum_to_bin(scalar1, scalar_b1, sizeof(scalar_b1),
-                            sae->tmp->prime_len);
        addr[1] = scalar_b1;
        len[1] = sae->tmp->prime_len;
        addr[2] = element1;
        len[2] = element1_len;
-       crypto_bignum_to_bin(scalar2, scalar_b2, sizeof(scalar_b2),
-                            sae->tmp->prime_len);
        addr[3] = scalar_b2;
        len[3] = sae->tmp->prime_len;
        addr[4] = element2;
        len[4] = element2_len;
-       hmac_sha256_vector(sae->tmp->kck, sizeof(sae->tmp->kck), 5, addr, len,
-                          confirm);
+       return hmac_sha256_vector(sae->tmp->kck, sizeof(sae->tmp->kck),
+                                 5, addr, len, confirm);
 }
 
 
-static void sae_cn_confirm_ecc(struct sae_data *sae, const u8 *sc,
-                              const struct crypto_bignum *scalar1,
-                              const struct crypto_ec_point *element1,
-                              const struct crypto_bignum *scalar2,
-                              const struct crypto_ec_point *element2,
-                              u8 *confirm)
+static int sae_cn_confirm_ecc(struct sae_data *sae, const u8 *sc,
+                             const struct crypto_bignum *scalar1,
+                             const struct crypto_ec_point *element1,
+                             const struct crypto_bignum *scalar2,
+                             const struct crypto_ec_point *element2,
+                             u8 *confirm)
 {
        u8 element_b1[2 * SAE_MAX_ECC_PRIME_LEN];
        u8 element_b2[2 * SAE_MAX_ECC_PRIME_LEN];
 
-       crypto_ec_point_to_bin(sae->tmp->ec, element1, element_b1,
-                              element_b1 + sae->tmp->prime_len);
-       crypto_ec_point_to_bin(sae->tmp->ec, element2, element_b2,
-                              element_b2 + sae->tmp->prime_len);
-
-       sae_cn_confirm(sae, sc, scalar1, element_b1, 2 * sae->tmp->prime_len,
-                      scalar2, element_b2, 2 * sae->tmp->prime_len, confirm);
+       if (crypto_ec_point_to_bin(sae->tmp->ec, element1, element_b1,
+                                  element_b1 + sae->tmp->prime_len) < 0 ||
+           crypto_ec_point_to_bin(sae->tmp->ec, element2, element_b2,
+                                  element_b2 + sae->tmp->prime_len) < 0 ||
+           sae_cn_confirm(sae, sc, scalar1, element_b1,
+                          2 * sae->tmp->prime_len,
+                          scalar2, element_b2, 2 * sae->tmp->prime_len,
+                          confirm) < 0)
+               return -1;
+       return 0;
 }
 
 
-static void sae_cn_confirm_ffc(struct sae_data *sae, const u8 *sc,
-                              const struct crypto_bignum *scalar1,
-                              const struct crypto_bignum *element1,
-                              const struct crypto_bignum *scalar2,
-                              const struct crypto_bignum *element2,
-                              u8 *confirm)
+static int sae_cn_confirm_ffc(struct sae_data *sae, const u8 *sc,
+                             const struct crypto_bignum *scalar1,
+                             const struct crypto_bignum *element1,
+                             const struct crypto_bignum *scalar2,
+                             const struct crypto_bignum *element2,
+                             u8 *confirm)
 {
        u8 element_b1[SAE_MAX_PRIME_LEN];
        u8 element_b2[SAE_MAX_PRIME_LEN];
 
-       crypto_bignum_to_bin(element1, element_b1, sizeof(element_b1),
-                            sae->tmp->prime_len);
-       crypto_bignum_to_bin(element2, element_b2, sizeof(element_b2),
-                            sae->tmp->prime_len);
-
-       sae_cn_confirm(sae, sc, scalar1, element_b1, sae->tmp->prime_len,
-                      scalar2, element_b2, sae->tmp->prime_len, confirm);
+       if (crypto_bignum_to_bin(element1, element_b1, sizeof(element_b1),
+                                sae->tmp->prime_len) < 0 ||
+           crypto_bignum_to_bin(element2, element_b2, sizeof(element_b2),
+                                sae->tmp->prime_len) < 0 ||
+           sae_cn_confirm(sae, sc, scalar1, element_b1, sae->tmp->prime_len,
+                          scalar2, element_b2, sae->tmp->prime_len,
+                          confirm) < 0)
+               return -1;
+       return 0;
 }
 
 
@@ -1282,22 +1288,22 @@ int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len)
 
        if (sae->tmp->ec) {
                if (!sae->tmp->peer_commit_element_ecc ||
-                   !sae->tmp->own_commit_element_ecc)
+                   !sae->tmp->own_commit_element_ecc ||
+                   sae_cn_confirm_ecc(sae, data, sae->peer_commit_scalar,
+                                      sae->tmp->peer_commit_element_ecc,
+                                      sae->tmp->own_commit_scalar,
+                                      sae->tmp->own_commit_element_ecc,
+                                      verifier) < 0)
                        return -1;
-               sae_cn_confirm_ecc(sae, data, sae->peer_commit_scalar,
-                                  sae->tmp->peer_commit_element_ecc,
-                                  sae->tmp->own_commit_scalar,
-                                  sae->tmp->own_commit_element_ecc,
-                                  verifier);
        } else {
                if (!sae->tmp->peer_commit_element_ffc ||
-                   !sae->tmp->own_commit_element_ffc)
+                   !sae->tmp->own_commit_element_ffc ||
+                   sae_cn_confirm_ffc(sae, data, sae->peer_commit_scalar,
+                                      sae->tmp->peer_commit_element_ffc,
+                                      sae->tmp->own_commit_scalar,
+                                      sae->tmp->own_commit_element_ffc,
+                                      verifier) < 0)
                        return -1;
-               sae_cn_confirm_ffc(sae, data, sae->peer_commit_scalar,
-                                  sae->tmp->peer_commit_element_ffc,
-                                  sae->tmp->own_commit_scalar,
-                                  sae->tmp->own_commit_element_ffc,
-                                  verifier);
        }
 
        if (os_memcmp_const(verifier, data + 2, SHA256_MAC_LEN) != 0) {