Always check bn_wexpend() return values for failure (CVE-2009-3245).

(The CHANGES entry covers the change from PR #2111 as well, submitted by
Martin Olsson.)

Submitted by: Neel Mehta

crypto/bn/bn_div.c

@@ -102,7 +102,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
 	/* The next 2 are needed so we can do a dv->d[0]|=1 later
 	 * since BN_lshift1 will only work once there is a value :-) */
 	BN_zero(dv);
-	bn_wexpand(dv,1);
+	if(bn_wexpand(dv,1) == NULL) goto end;
 	dv->top=1;
 
 	if (!BN_lshift(D,D,nm-nd)) goto end;

crypto/bn/bn_gf2m.c

@@ -232,7 +232,8 @@ int	BN_GF2m_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
 	if (a->top < b->top) { at = b; bt = a; }
 	else { at = a; bt = b; }
 
-	bn_wexpand(r, at->top);
+	if(bn_wexpand(r, at->top) == NULL)
+		return 0;
 
 	for (i = 0; i < bt->top; i++)
 		{

crypto/ec/ec2_smpl.c

@@ -176,8 +176,8 @@ int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
 	dest->poly[3] = src->poly[3];
 	dest->poly[4] = src->poly[4];
 	dest->poly[5] = src->poly[5];
-	bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
-	bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+	if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
+	if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
 	for (i = dest->a.top; i < dest->a.dmax; i++) dest->a.d[i] = 0;
 	for (i = dest->b.top; i < dest->b.dmax; i++) dest->b.d[i] = 0;
 	return 1;
@@ -201,12 +201,12 @@ int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
 
 	/* group->a */
 	if (!BN_GF2m_mod_arr(&group->a, a, group->poly)) goto err;
-	bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+	if(bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
 	for (i = group->a.top; i < group->a.dmax; i++) group->a.d[i] = 0;
 	
 	/* group->b */
 	if (!BN_GF2m_mod_arr(&group->b, b, group->poly)) goto err;
-	bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2);
+	if(bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
 	for (i = group->b.top; i < group->b.dmax; i++) group->b.d[i] = 0;
 		
 	ret = 1;

engines/e_ubsec.c

@@ -935,7 +935,7 @@ static int ubsec_dh_generate_key(DH *dh)
                 priv_key = BN_new();
                 if (priv_key == NULL) goto err;
                 priv_key_len = BN_num_bits(dh->p);
-                bn_wexpand(priv_key, dh->p->top);
+                if(bn_wexpand(priv_key, dh->p->top) == NULL) goto err;
                 do
                         if (!BN_rand_range(priv_key, dh->p)) goto err;
                 while (BN_is_zero(priv_key));
@@ -950,7 +950,7 @@ static int ubsec_dh_generate_key(DH *dh)
                 {
                 pub_key = BN_new();
                 pub_key_len = BN_num_bits(dh->p);
-                bn_wexpand(pub_key, dh->p->top);
+                if(bn_wexpand(pub_key, dh->p->top) == NULL) goto err;
                 if(pub_key == NULL) goto err;
                 }
         else