use mp_cleanup_multi()

src/pk/dh/dh_free.c

@@ -18,22 +18,7 @@
 void dh_free(dh_key *key)
 {
    LTC_ARGCHKVD(key != NULL);
-   if ( key->base ) {
-      mp_clear( key->base );
-      key->base = NULL;
-   }
-   if ( key->prime ) {
-      mp_clear( key->prime );
-      key->prime = NULL;
-   }
-   if ( key->x ) {
-      mp_clear( key->x );
-      key->x = NULL;
-   }
-   if ( key->y ) {
-      mp_clear( key->y );
-      key->y = NULL;
-   }
+   mp_cleanup_multi(&key->base, &key->prime, &key->x, &key->y, NULL);
 }
 
 #endif /* LTC_MDH */

src/pk/dsa/dsa_free.c

@@ -22,7 +22,8 @@
 void dsa_free(dsa_key *key)
 {
    LTC_ARGCHKVD(key != NULL);
-   mp_clear_multi(key->g, key->q, key->p, key->x, key->y, NULL);
+   mp_cleanup_multi(&key->g, &key->q, &key->p, &key->x, &key->y, NULL);
+   key->type = key->qord = 0;
 }
 
 #endif

src/pk/rsa/rsa_free.c

@@ -22,7 +22,7 @@
 void rsa_free(rsa_key *key)
 {
    LTC_ARGCHKVD(key != NULL);
-   mp_clear_multi(key->q, key->p, key->qP, key->dP, key->dQ, key->N, key->d, key->e, NULL);
+   mp_cleanup_multi(&key->q, &key->p, &key->qP, &key->dP, &key->dQ, &key->N, &key->d, &key->e, NULL);
 }
 
 #endif