Fix potential memory leak

[openssl-gost/engine.git] / gost_ec_keyx.c

diff --git a/gost_ec_keyx.c b/gost_ec_keyx.c
index 6efa3e870b06d54d22dd8e8c3c26255f9966a615..fa068aec45c0fcacaf37bc8415d4d954481bc3f1 100644 (file)
--- a/gost_ec_keyx.c
+++ b/gost_ec_keyx.c
@@ -18,13 +18,13 @@
 #include "gost_lcl.h"
 
 /* Implementation of CryptoPro VKO 34.10-2001/2012 algorithm */
-static int VKO_compute_key(unsigned char *shared_key,
-                           const EC_POINT *pub_key, const EC_KEY *priv_key,
-                           const unsigned char *ukm, const size_t ukm_size,
-                           const int vko_dgst_nid)
+int VKO_compute_key(unsigned char *shared_key,
+                    const EC_POINT *pub_key, const EC_KEY *priv_key,
+                    const unsigned char *ukm, const size_t ukm_size,
+                    const int vko_dgst_nid)
 {
     unsigned char *databuf = NULL;
-    BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL;
+    BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL, *cofactor = NULL;
     const BIGNUM *key = EC_KEY_get0_private_key(priv_key);
     EC_POINT *pnt = EC_POINT_new(EC_KEY_get0_group(priv_key));
     BN_CTX *ctx = BN_CTX_new();
@@ -48,16 +48,22 @@ static int VKO_compute_key(unsigned char *shared_key,
     UKM = hashsum2bn(ukm, ukm_size);
     p = BN_CTX_get(ctx);
     order = BN_CTX_get(ctx);
+               cofactor = BN_CTX_get(ctx);
     X = BN_CTX_get(ctx);
     Y = BN_CTX_get(ctx);
     EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx);
+               EC_GROUP_get_cofactor(EC_KEY_get0_group(priv_key), cofactor, ctx);
+    BN_mod_mul(UKM, UKM, cofactor, order, ctx);
     BN_mod_mul(p, key, UKM, order, ctx);
     if (!EC_POINT_mul(EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx)) {
         GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_ERROR_POINT_MUL);
         goto err;
     }
-    EC_POINT_get_affine_coordinates(EC_KEY_get0_group(priv_key),
-                                        pnt, X, Y, ctx);
+    if (!EC_POINT_get_affine_coordinates(EC_KEY_get0_group(priv_key),
+                                        pnt, X, Y, ctx)) {
+       GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_EC_LIB);
+       goto err;
+    }
 
     half_len = BN_num_bytes(order);
     buf_len = 2 * half_len;