/**
* @param ScriptInterface $scriptSig
* @param ScriptInterface $scriptPubKey
* @param int $flags
* @param Checker $checker
* @param ScriptWitnessInterface|null $witness
* @return bool
*/
public function verify(ScriptInterface $scriptSig, ScriptInterface $scriptPubKey, $flags, Checker $checker, ScriptWitnessInterface $witness = null)
{
static $emptyWitness = null;
if ($emptyWitness === null) {
$emptyWitness = new ScriptWitness([]);
}
$witness = $witness ?: $emptyWitness;
if (($flags & self::VERIFY_SIGPUSHONLY) != 0 && !$scriptSig->isPushOnly()) {
return false;
}
$stack = new Stack();
if (!$this->evaluate($scriptSig, $stack, 0, $flags, $checker)) {
return false;
}
$backup = [];
if ($flags & self::VERIFY_P2SH) {
foreach ($stack as $s) {
$backup[] = $s;
}
}
if (!$this->evaluate($scriptPubKey, $stack, 0, $flags, $checker)) {
return false;
}
if ($stack->isEmpty()) {
return false;
}
if (false === $this->castToBool($stack[-1])) {
return false;
}
$program = null;
if ($flags & self::VERIFY_WITNESS) {
if ($scriptPubKey->isWitness($program)) {
/** @var WitnessProgram $program */
if ($scriptSig->getBuffer()->getSize() !== 0) {
return false;
}
if (!$this->verifyWitnessProgram($program, $witness, $flags, $checker)) {
return false;
}
$stack->resize(1);
}
}
if ($flags & self::VERIFY_P2SH && (new OutputClassifier($scriptPubKey))->isPayToScriptHash()) {
if (!$scriptSig->isPushOnly()) {
return false;
}
$stack = new Stack();
foreach ($backup as $i) {
$stack->push($i);
}
// Restore mainStack to how it was after evaluating scriptSig
if ($stack->isEmpty()) {
return false;
}
// Load redeemscript as the scriptPubKey
$scriptPubKey = new Script($stack->bottom());
$stack->pop();
if (!$this->evaluate($scriptPubKey, $stack, 0, $flags, $checker)) {
return false;
}
if ($stack->isEmpty()) {
return false;
}
if (!$this->castToBool($stack->bottom())) {
return false;
}
if ($flags & self::VERIFY_WITNESS) {
if ($scriptPubKey->isWitness($program)) {
/** @var WitnessProgram $program */
if ($scriptSig != ScriptFactory::create()->push($scriptPubKey->getBuffer())->getScript()) {
return false;
// SCRIPT_ERR_WITNESS_MALLEATED_P2SH
}
if (!$this->verifyWitnessProgram($program, $witness, $flags, $checker)) {
return false;
}
$stack->resize(1);
}
}
}
if ($flags & self::VERIFY_CLEAN_STACK != 0) {
if (!($flags & self::VERIFY_P2SH != 0 && $flags & self::VERIFY_WITNESS != 0)) {
return false;
// implied flags required
}
if (count($stack) != 1) {
return false;
// Cleanstack
}
}
if ($flags & self::VERIFY_WITNESS) {
if (!$flags & self::VERIFY_P2SH) {
return false;
//
}
if ($program === null && !$witness->isNull()) {
return false;
// SCRIPT_ERR_WITNESS_UNEXPECTED
}
}
return true;
}
