#include "config.h" #include #include #include #include #include #include struct bitcoin_tx *create_close_tx(const tal_t *ctx, const struct chainparams *chainparams, u32 *local_wallet_index, const struct ext_key *local_wallet_ext_key, const u8 *our_script, const u8 *their_script, const u8 *funding_wscript, const struct bitcoin_outpoint *funding, struct amount_sat funding_sats, struct amount_sat to_us, struct amount_sat to_them, struct amount_sat dust_limit) { struct bitcoin_tx *tx; size_t num_outputs = 0; struct amount_sat total_out; u8 *script; assert(amount_sat_add(&total_out, to_us, to_them)); assert(amount_sat_less_eq(total_out, funding_sats)); /* BOLT #3: * * ## Closing Transaction * * Note that there are two possible variants for each node. * * * version: 2 * * locktime: 0 * * txin count: 1 */ /* Now create close tx: one input, two outputs. */ tx = bitcoin_tx(ctx, chainparams, 1, 2, 0); /* Our input spends the anchor tx output. */ bitcoin_tx_add_input(tx, funding, BITCOIN_TX_DEFAULT_SEQUENCE, NULL, funding_sats, NULL, funding_wscript); if (amount_sat_greater_eq(to_us, dust_limit)) { script = tal_dup_talarr(tx, u8, our_script); /* One output is to us. */ bitcoin_tx_add_output(tx, script, NULL, to_us); assert((local_wallet_index == NULL) == (local_wallet_ext_key == NULL)); if (local_wallet_index) { size_t script_len = tal_bytelen(script); psbt_add_keypath_to_last_output( tx, *local_wallet_index, local_wallet_ext_key, is_p2tr(script, script_len, NULL)); } num_outputs++; } if (amount_sat_greater_eq(to_them, dust_limit)) { script = tal_dup_talarr(tx, u8, their_script); /* Other output is to them. */ bitcoin_tx_add_output(tx, script, NULL, to_them); num_outputs++; } /* Can't have no outputs at all! */ if (num_outputs == 0) return tal_free(tx); permute_outputs(tx, NULL, NULL); bitcoin_tx_finalize(tx); assert(bitcoin_tx_check(tx)); return tx; }