psbt: use control block verification call internally

Author: jgriffiths

src/psbt.c

@@ -2217,22 +2217,15 @@ static int pull_taproot_leaf_signature(const unsigned char **cursor, size_t *max
     return map_add(leaf_sigs, xonly_hash, 64u, val, val_len, false, false);
 }
 
-static bool is_valid_control_block_len(size_t ctrl_len)
-{
-    return ctrl_len >= 33u && ctrl_len <= 33u + 128u * 32u &&
-           ((ctrl_len - 33u) % 32u) == 0;
-}
-
 static int pull_taproot_leaf_script(const unsigned char **cursor, size_t *max,
                                     const unsigned char **key, size_t *key_len,
                                     struct wally_map *leaf_scripts)
 {
-    /* TODO: use taproot constants here */
     const unsigned char *ctrl, *val;
     size_t ctrl_len = *key_len, val_len;
 
     ctrl = pull_skip(key, key_len, ctrl_len);
-    if (!ctrl || !is_valid_control_block_len(ctrl_len))
+    if (wally_bip341_control_block_verify(ctrl, ctrl_len) != WALLY_OK)
         return WALLY_EINVAL;
     subfield_nomore_end(cursor, max, *key, *key_len);
 
@@ -2987,7 +2980,8 @@ static int push_taproot_leaf_scripts(unsigned char **cursor, size_t *max, size_t
     for (i = 0; i < leaf_scripts->num_items; ++i) {
         const struct wally_map_item *item = leaf_scripts->items + i;
 
-        if (!is_valid_control_block_len(item->key_len) || !item->value_len)
+        if (wally_bip341_control_block_verify(item->key, item->key_len) != WALLY_OK ||
+            !item->value_len)
             return WALLY_EINVAL;
 
         push_key(cursor, max, ft, false, item->key, item->key_len);