Fix BN_to_ASN1_INTEGER() misuse

You can either let this API reuse an existing ASN1_INTEGER or you can let
it allocate a new one. If you try to do both at the same time, you'll leak.

ok jsing

diff --git a/lib/libcrypto/ec/ec_asn1.c b/lib/libcrypto/ec/ec_asn1.c
index 2ce7d78..504948b 100644 (file)
--- a/lib/libcrypto/ec/ec_asn1.c
+++ b/lib/libcrypto/ec/ec_asn1.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_asn1.c,v 1.53 2024/04/17 23:24:18 tb Exp $ */
+/* $OpenBSD: ec_asn1.c,v 1.54 2024/10/03 04:15:52 tb Exp $ */
 /*
  * Written by Nils Larsch for the OpenSSL project.
  */
@@ -760,20 +760,19 @@ ec_asn1_group2parameters(const EC_GROUP *group, ECPARAMETERS *param)
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
-       /* set the order */
        if (!EC_GROUP_get_order(group, tmp, NULL)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
-       ret->order = BN_to_ASN1_INTEGER(tmp, ret->order);
-       if (ret->order == NULL) {
+       ASN1_INTEGER_free(ret->order);
+       if ((ret->order = BN_to_ASN1_INTEGER(tmp, NULL)) == NULL) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
-       /* set the cofactor (optional) */
+       ASN1_INTEGER_free(ret->cofactor);
+       ret->cofactor = NULL;
        if (EC_GROUP_get_cofactor(group, tmp, NULL)) {
-               ret->cofactor = BN_to_ASN1_INTEGER(tmp, ret->cofactor);
-               if (ret->cofactor == NULL) {
+               if ((ret->cofactor = BN_to_ASN1_INTEGER(tmp, NULL)) == NULL) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }