/**
* Calculate the hash of the current transaction, when you are looking to
* spend $txOut, and are signing $inputToSign. The SigHashType defaults to
* SIGHASH_ALL, though SIGHASH_SINGLE, SIGHASH_NONE, SIGHASH_ANYONECANPAY
* can be used.
*
* @param ScriptInterface $txOutScript
* @param int $inputToSign
* @param int $sighashType
* @return BufferInterface
* @throws \Exception
*/
public function calculate(ScriptInterface $txOutScript, $inputToSign, $sighashType = SigHash::ALL)
{
$math = Bitcoin::getMath();
$tx = new TxMutator($this->transaction);
$inputs = $tx->inputsMutator();
$outputs = $tx->outputsMutator();
// Default SIGHASH_ALL procedure: null all input scripts
foreach ($inputs as $input) {
$input->script(new Script());
}
$inputs[$inputToSign]->script($txOutScript);
if ($math->cmp($math->bitwiseAnd($sighashType, 31), SigHash::NONE) === 0) {
// Set outputs to empty vector, and set sequence number of inputs to 0.
$outputs->null();
// Let the others update at will. Set sequence of inputs we're not signing to 0.
foreach ($inputs as $i => $input) {
if ($i !== $inputToSign) {
$input->sequence(0);
}
}
} elseif ($math->cmp($math->bitwiseAnd($sighashType, 31), SigHash::SINGLE) === 0) {
// Resize output array to $inputToSign + 1, set remaining scripts to null,
// and set sequence's to zero.
$nOutput = $inputToSign;
if ($nOutput >= $this->nOutputs) {
return Buffer::hex('0100000000000000000000000000000000000000000000000000000000000000', 32, $math);
}
// Resize, set to null
$outputs->slice(0, $nOutput + 1);
for ($i = 0; $i < $nOutput; $i++) {
$outputs[$i]->null();
}
// Let the others update at will. Set sequence of inputs we're not signing to 0
foreach ($inputs as $i => $input) {
if ($i !== $inputToSign) {
$input->sequence(0);
}
}
}
// This can happen regardless of whether it's ALL, NONE, or SINGLE
if ($math->cmp($math->bitwiseAnd($sighashType, SigHash::ANYONECANPAY), 0) > 0) {
$input = $inputs[$inputToSign]->done();
$inputs->null()->add($input);
}
return Hash::sha256d(Buffertools::concat($tx->done()->getBuffer(), Buffertools::flipBytes(Buffer::int($sighashType, 4, $math))));
}
/**
* @return TransactionInterface
*/
public function get()
{
$mutator = new TxMutator($this->transaction);
$inputs = $mutator->inputsMutator();
$txInputs = $this->transaction->getInputs();
$i = 0;
foreach ($inputs as $input) {
// Call regenerateScript if inputState is set, otherwise defer to previous script.
try {
$script = $this->inputState($i)->regenerateScript();
} catch (BuilderNoInputState $e) {
$script = $txInputs[$i]->getScript();
}
$input->script($script);
$i++;
}
return $mutator->done();
}
