aljaz/lightning
1
0
Fork 0
mirror of https://github.com/aljazceru/lightning.git synced 2026-01-21 06:44:21 +01:00
Code Issues Packages Projects Releases Wiki Activity

withdraw: refactor change output handling

Browse Source 
We're not using the change_outnum for withdraw tx's (and the way
we were calculating it was broken as of the addition of 'multiple
outputs'). This removes the change output knowhow from withdraw_tx
entirely, and pushes the responsibility up to the caller to
include the change output in the output set if desired.

Consequently, we also remove the change output knowhow from hsmd.
This commit is contained in:
lisa neigut
2019-09-16 19:08:05 -05:00
committed by Christian Decker
parent 09815c7e7f
commit 16656a85cf
8 changed files with 39 additions and 67 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
common/withdraw_tx.c
View File

@@ -3,6 +3,7 @@
#include <bitcoin/pubkey.h>
#include <bitcoin/script.h>
#include <ccan/ptrint/ptrint.h>
#include <common/key_derive.h>
#include <common/permute_tx.h>
#include <common/utils.h>
#include <common/utxo.h>
@@ -13,44 +14,20 @@ struct bitcoin_tx *withdraw_tx(const tal_t *ctx,
const struct chainparams *chainparams,
const struct utxo **utxos,
struct bitcoin_tx_output **outputs,
const struct pubkey *changekey,
struct amount_sat change,
const struct ext_key *bip32_base,
int *change_outnum, u32 nlocktime)
u32 nlocktime)
{
struct bitcoin_tx *tx;
int output_count;
tx = tx_spending_utxos(ctx, chainparams, utxos, bip32_base,
!amount_sat_eq(change, AMOUNT_SAT(0)),
tal_count(outputs), nlocktime,
false, tal_count(outputs), nlocktime,
BITCOIN_TX_DEFAULT_SEQUENCE - 1);
output_count = bitcoin_tx_add_multi_outputs(tx, outputs);
assert(output_count == tal_count(outputs));
if (!amount_sat_eq(change, AMOUNT_SAT(0))) {
/* Add one to the output_count, for the change */
output_count++;
const void *map[output_count];
for (size_t i = 0; i < output_count; i++)
map[i] = int2ptr(i);
bitcoin_tx_add_output(tx, scriptpubkey_p2wpkh(tmpctx, changekey),
NULL, change);
assert(tx->wtx->num_outputs == output_count);
permute_outputs(tx, NULL, map);
/* The change is the last output added, so the last position
* in the map */
if (change_outnum)
*change_outnum = ptr2int(map[output_count - 1]);
} else if (change_outnum)
*change_outnum = -1;
permute_outputs(tx, NULL, (const void **)outputs);
permute_inputs(tx, (const void **)utxos);
bitcoin_tx_finalize(tx);

7
common/withdraw_tx.h
View File

@@ -21,19 +21,14 @@ struct utxo;
* @chainparams: (in) the params for the created transaction.
* @utxos: (in/out) tal_arr of UTXO pointers to spend (permuted to match)
* @outputs: (in) tal_arr of bitcoin_tx_output, scriptPubKeys with amount to send to.
* @changekey: (in) key to send change to (only used if change_satoshis != 0).
* @change: (in) amount to send as change.
* @bip32_base: (in) bip32 base for key derivation, or NULL.
* @change_outnum: (out) set to output index of change output or -1 if none, unless NULL.
* @nlocktime: (in) the value to set as the transaction's nLockTime.
*/
struct bitcoin_tx *withdraw_tx(const tal_t *ctx,
const struct chainparams *chainparams,
const struct utxo **utxos,
struct bitcoin_tx_output **outputs,
const struct pubkey *changekey,
struct amount_sat change,
const struct ext_key *bip32_base,
int *change_outnum, u32 nlocktime);
u32 nlocktime);
#endif /* LIGHTNING_COMMON_WITHDRAW_TX_H */