/**
* TxSignerContext constructor.
* @param EcAdapterInterface $ecAdapter
* @param ScriptInterface $outputScript
* @param ScriptInterface|null $redeemScript
*/
public function __construct(EcAdapterInterface $ecAdapter, ScriptInterface $outputScript, ScriptInterface $redeemScript = null)
{
$handler = ScriptFactory::info($outputScript, $redeemScript);
$handler->getKeys();
$this->scriptType = $this->prevOutType = $handler->classification();
if ($handler instanceof ScriptHash) {
$this->scriptType = $handler->getInfo()->classification();
}
// Gather public keys from redeemScript / outputScript
$this->ecAdapter = $ecAdapter;
$this->redeemScript = $redeemScript;
$this->prevOutScript = $outputScript;
$this->scriptInfo = $handler;
// According to scriptType, extract public keys
$this->publicKeys = $this->scriptInfo->getKeys();
}
/**
* @param TransactionInterface $tx
* @param $inputToExtract
* @return $this
*/
public function extractSigs(TransactionInterface $tx, $inputToExtract)
{
$inputs = $tx->getInputs();
$parsed = $inputs[$inputToExtract]->getScript()->getScriptParser()->decode();
$size = count($parsed);
switch ($this->getScriptType()) {
case OutputClassifier::PAYTOPUBKEYHASH:
// Supply signature and public key in scriptSig
if ($size === 2) {
$this->signatures = [TransactionSignatureFactory::fromHex($parsed[0]->getData(), $this->ecAdapter)];
$this->publicKeys = [PublicKeyFactory::fromHex($parsed[1]->getData(), $this->ecAdapter)];
}
break;
case OutputClassifier::PAYTOPUBKEY:
// Only has a signature in the scriptSig
if ($size === 1) {
$this->signatures = [TransactionSignatureFactory::fromHex($parsed[0]->getData(), $this->ecAdapter)];
}
break;
case OutputClassifier::MULTISIG:
$redeemScript = $this->getRedeemScript();
$keys = $this->scriptInfo->getKeys();
foreach ($keys as $idx => $key) {
$this->setSignature($idx, null);
}
if ($size > 2 && $size <= $this->scriptInfo->getKeyCount() + 2) {
$sigs = [];
foreach ($keys as $key) {
$sigs[$key->getPubKeyHash()->getHex()] = [];
}
// Extract Signatures (as buffers), then compile arrays of [pubkeyHash => signature]
$sigHash = new Hasher($tx);
foreach (array_slice($parsed, 1, -1) as $item) {
/** @var \BitWasp\Bitcoin\Script\Parser\Operation $item */
if ($item->isPush()) {
$txSig = TransactionSignatureFactory::fromHex($item->getData(), $this->ecAdapter);
$linked = $this->ecAdapter->associateSigs([$txSig->getSignature()], $sigHash->calculate($redeemScript, $inputToExtract, $txSig->getHashType()), $keys);
if (count($linked)) {
$key = array_keys($linked)[0];
$sigs[$key] = array_merge($sigs[$key], [$txSig]);
}
}
}
// We have all the signatures from the tx now. array_shift the sigs for a public key, as it's encountered.
foreach ($keys as $idx => $key) {
$hash = $key->getPubKeyHash()->getHex();
$this->setSignature($idx, isset($sigs[$hash]) ? array_shift($sigs[$hash]) : null);
}
}
break;
}
return $this;
}
/**
* @return \BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface[]
*/
public function getKeys()
{
return $this->handler->getKeys();
}
