void bp_tx_sigserializer(cstring *s, const cstring *scriptCode,
const struct bp_tx *txTo, unsigned int nIn,
int nHashType)
{
const bool fAnyoneCanPay = (!!(nHashType & SIGHASH_ANYONECANPAY));
const bool fHashSingle = ((nHashType & 0x1f) == SIGHASH_SINGLE);
const bool fHashNone = ((nHashType & 0x1f) == SIGHASH_NONE);
/** Serialize txTo */
// Serialize nVersion
ser_u32(s, txTo->nVersion);
// Serialize vin
unsigned int nInputs = fAnyoneCanPay ? 1 : txTo->vin->len;
ser_varlen(s, nInputs);
unsigned int nInput;
for (nInput = 0; nInput < nInputs; nInput++) {
/** Serialize an input of txTo */
// In case of SIGHASH_ANYONECANPAY, only the input being signed is serialized
if (fAnyoneCanPay)
nInput = nIn;
struct bp_txin *txin = parr_idx(txTo->vin, nInput);
// Serialize the prevout
ser_bp_outpt(s, &txin->prevout);
// Serialize the script
if (nInput != nIn)
// Blank out other inputs' signatures
ser_varlen(s, (int)0);
else if (scriptCode == NULL)
cstr_append_c(s, 0);
else {
/** Serialize the passed scriptCode, skipping OP_CODESEPARATORs */
struct const_buffer it = { scriptCode->str, scriptCode->len };
struct const_buffer itBegin = it;
struct bscript_op op;
unsigned int nCodeSeparators = 0;
struct bscript_parser bp;
bsp_start(&bp, &it);
while (bsp_getop(&op, &bp)) {
if (op.op == OP_CODESEPARATOR)
nCodeSeparators++;
}
ser_varlen(s, scriptCode->len - nCodeSeparators);
it = itBegin;
bsp_start(&bp, &it);
while (bsp_getop(&op, &bp)) {
if (op.op == OP_CODESEPARATOR) {
ser_bytes(s, itBegin.p, it.p - itBegin.p - 1);
itBegin = it;
}
}
if (itBegin.p != scriptCode->str + scriptCode->len)
ser_bytes(s, itBegin.p, it.p - itBegin.p);
}
// Serialize the nSequence
if ((nInput != nIn) && (fHashSingle || fHashNone))
// let the others update at will
ser_u32(s, (int)0);
else
ser_u32(s, txin->nSequence);
}
// Serialize vout
unsigned int nOutputs = fHashNone ? 0 : (fHashSingle ? (nIn + 1) : txTo->vout->len);
ser_varlen(s, nOutputs);
unsigned int nOutput;
for (nOutput = 0; nOutput < nOutputs; nOutput++) {
struct bp_txout *txout = parr_idx(txTo->vout, nOutput);
if (fHashSingle && (nOutput != nIn))
// Do not lock-in the txout payee at other indices as txin;
bp_txout_set_null(txout);
ser_bp_txout(s, txout);
}
// Serialize nLockTime
ser_u32(s, txTo->nLockTime);
}
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);
}
