void bp_tx_sighash(bu256_t *hash, const cstring *scriptCode,
const struct bp_tx *txTo, unsigned int nIn,
int nHashType)
{
if (nIn >= txTo->vin->len) {
// nIn out of range
bu256_set_u64(hash, 1);
return;
}
// Check for invalid use of SIGHASH_SINGLE
if ((nHashType & 0x1f) == SIGHASH_SINGLE) {
if (nIn >= txTo->vout->len) {
// nOut out of range
bu256_set_u64(hash, 1);
return;
}
}
cstring *s = cstr_new_sz(512);
// Serialize only the necessary parts of the transaction being signed
bp_tx_sigserializer(s, scriptCode, txTo, nIn, nHashType);
ser_s32(s, nHashType);
bu_Hash((unsigned char *) hash, s->str, s->len);
cstr_free(s, true);
}
void bp_tx_sighash(bu256_t *hash, const GString *scriptCode,
const struct bp_tx *txTo, unsigned int nIn,
int nHashType)
{
if (nIn >= txTo->vin->len) {
bu256_set_u64(hash, 1);
goto out;
}
struct bp_tx txTmp;
bp_tx_init(&txTmp);
bp_tx_copy(&txTmp, txTo);
/* TODO: find-and-delete OP_CODESEPARATOR from scriptCode */
/* Blank out other inputs' signatures */
unsigned int i;
struct bp_txin *txin;
for (i = 0; i < txTmp.vin->len; i++) {
txin = g_ptr_array_index(txTmp.vin, i);
g_string_set_size(txin->scriptSig, 0);
if (i == nIn)
g_string_append_len(txin->scriptSig,
scriptCode->str, scriptCode->len);
}
/* Blank out some of the outputs */
if ((nHashType & 0x1f) == SIGHASH_NONE) {
/* Wildcard payee */
bp_tx_free_vout(&txTmp);
txTmp.vout = g_ptr_array_new_full(1, g_free);
/* Let the others update at will */
for (i = 0; i < txTmp.vin->len; i++) {
txin = g_ptr_array_index(txTmp.vin, i);
if (i != nIn)
txin->nSequence = 0;
}
}
else if ((nHashType & 0x1f) == SIGHASH_SINGLE) {
/* Only lock-in the txout payee at same index as txin */
unsigned int nOut = nIn;
if (nOut >= txTmp.vout->len) {
bu256_set_u64(hash, 1);
goto out;
}
g_ptr_array_set_size(txTmp.vout, nOut + 1);
for (i = 0; i < nOut; i++) {
struct bp_txout *txout;
txout = g_ptr_array_index(txTmp.vout, i);
bp_txout_set_null(txout);
}
/* Let the others update at will */
for (i = 0; i < txTmp.vin->len; i++) {
txin = g_ptr_array_index(txTmp.vin, i);
if (i != nIn)
txin->nSequence = 0;
}
}
/* Blank out other inputs completely;
not recommended for open transactions */
if (nHashType & SIGHASH_ANYONECANPAY) {
if (nIn > 0)
g_ptr_array_remove_range(txTmp.vin, 0, nIn);
g_ptr_array_set_size(txTmp.vin, 1);
}
/* Serialize and hash */
bp_tx_calc_sighash(hash, &txTmp, nHashType);
out:
bp_tx_free(&txTmp);
}
