psbt: add method to finalize + extract a psbt

will either use a temporary psbt (and not munge the passed in psbt)
or will finalize in place -- finalization erases most of the signature
metadata from the psbt struct
This commit is contained in:
niftynei 2020-06-06 14:47:40 -05:00 committed by Christian Decker
parent 0d1f1bc66e
commit b63abef542
3 changed files with 37 additions and 23 deletions

View file

@ -340,6 +340,38 @@ struct amount_sat psbt_input_get_amount(struct wally_psbt *psbt,
return val;
}
struct wally_tx *psbt_finalize(struct wally_psbt *psbt, bool finalize_in_place)
{
struct wally_psbt *tmppsbt;
struct wally_tx *wtx;
/* We want the 'finalized' tx since that includes any signature
* data, not the global tx. But 'finalizing' a tx destroys some fields
* so we 'clone' it first and then finalize it */
if (!finalize_in_place) {
if (wally_psbt_clone(psbt, &tmppsbt) != WALLY_OK)
return NULL;
} else
tmppsbt = cast_const(struct wally_psbt *, psbt);
if (wally_finalize_psbt(tmppsbt) != WALLY_OK) {
if (!finalize_in_place)
wally_psbt_free(tmppsbt);
return NULL;
}
if (psbt_is_finalized(tmppsbt)
&& wally_extract_psbt(tmppsbt, &wtx) == WALLY_OK) {
if (!finalize_in_place)
wally_psbt_free(tmppsbt);
return wtx;
}
if (!finalize_in_place)
wally_psbt_free(tmppsbt);
return NULL;
}
bool psbt_from_b64(const char *b64str, struct wally_psbt **psbt)
{
int wally_err;

View file

@ -32,6 +32,8 @@ struct wally_psbt *new_psbt(const tal_t *ctx,
*/
bool psbt_is_finalized(struct wally_psbt *psbt);
struct wally_tx *psbt_finalize(struct wally_psbt *psbt, bool finalize_in_place);
struct wally_psbt_input *psbt_add_input(struct wally_psbt *psbt,
struct wally_tx_input *input,
size_t insert_at);

View file

@ -501,38 +501,18 @@ char *bitcoin_tx_to_psbt_base64(const tal_t *ctx, struct bitcoin_tx *tx)
struct bitcoin_tx *bitcoin_tx_with_psbt(const tal_t *ctx, struct wally_psbt *psbt STEALS)
{
struct wally_psbt *tmppsbt;
struct bitcoin_tx *tx = bitcoin_tx(ctx, chainparams,
psbt->tx->num_inputs,
psbt->tx->num_outputs,
psbt->tx->locktime);
wally_tx_free(tx->wtx);
/* We want the 'finalized' tx since that includes any signature
* data, not the global tx. But 'finalizing' a tx destroys some fields
* so we 'clone' it first and then finalize it */
if (wally_psbt_clone(psbt, &tmppsbt) != WALLY_OK)
tx->wtx = psbt_finalize(psbt, false);
if (!tx->wtx && wally_tx_clone(psbt->tx, &tx->wtx) != WALLY_OK)
return NULL;
if (wally_finalize_psbt(tmppsbt) != WALLY_OK) {
wally_psbt_free(tmppsbt);
return NULL;
}
if (psbt_is_finalized(tmppsbt)) {
if (wally_extract_psbt(tmppsbt, &tx->wtx) != WALLY_OK) {
wally_psbt_free(tmppsbt);
return NULL;
}
} else if (wally_tx_clone(psbt->tx, &tx->wtx) != WALLY_OK) {
wally_psbt_free(tmppsbt);
return NULL;
}
wally_psbt_free(tmppsbt);
tal_free(tx->psbt);
tx->psbt = tal_steal(tx, psbt);
return tx;
}