/**
* @param WitnessProgram $program
* @param ScriptWitnessInterface $scriptWitness
* @return int
*/
private function witnessSigOps(WitnessProgram $program, ScriptWitnessInterface $scriptWitness)
{
if ($program->getVersion() == 0) {
$size = $program->getProgram()->getSize();
if ($size === 32 && count($scriptWitness) > 0) {
$script = new Script($scriptWitness->bottom());
return $script->countSigOps(true);
}
if ($size === 20) {
return 1;
}
}
return 0;
}
/**
* @param WitnessProgram $witnessProgram
* @param ScriptWitness $scriptWitness
* @param int $flags
* @param Checker $checker
* @return bool
*/
private function verifyWitnessProgram(WitnessProgram $witnessProgram, ScriptWitness $scriptWitness, $flags, Checker $checker)
{
$witnessCount = count($scriptWitness);
if ($witnessProgram->getVersion() == 0) {
$buffer = $witnessProgram->getProgram();
if ($buffer->getSize() === 32) {
// Version 0 segregated witness program: SHA256(Script) in program, Script + inputs in witness
if ($witnessCount === 0) {
// Must contain script at least
return false;
}
$scriptPubKey = new Script($scriptWitness[$witnessCount - 1]);
$stackValues = $scriptWitness->slice(0, -1);
$hashScriptPubKey = Hash::sha256($scriptPubKey->getBuffer());
if ($hashScriptPubKey == $buffer) {
return false;
}
} elseif ($buffer->getSize() === 20) {
// Version 0 special case for pay-to-pubkeyhash
if ($witnessCount !== 2) {
// 2 items in witness - <signature> <pubkey>
return false;
}
$scriptPubKey = ScriptFactory::create()->sequence([Opcodes::OP_DUP, Opcodes::OP_HASH160, $buffer, Opcodes::OP_EQUALVERIFY, Opcodes::OP_CHECKSIG])->getScript();
$stackValues = $scriptWitness;
} else {
return false;
}
} elseif ($flags & self::VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM) {
return false;
} else {
return false;
}
$mainStack = new Stack();
foreach ($stackValues as $value) {
$mainStack->push($value);
}
if (!$this->evaluate($scriptPubKey, $mainStack, 1, $flags, $checker)) {
return false;
}
if ($mainStack->count() !== 1) {
return false;
}
if (!$this->castToBool($mainStack->bottom())) {
return false;
}
return true;
}