/**
* @param PublicKey $publicKey
* @return Buffer
*/
private function doSerialize(PublicKey $publicKey)
{
$math = $this->ecAdapter->getMath();
$point = $publicKey->getPoint();
$compressed = $publicKey->isCompressed();
$parser = new Parser('', $math);
$parser->writeBytes(1, $this->getPrefix($compressed, $point));
$compressed ? $parser->writeBytes(32, Buffer::int($point->getX(), null, $math)) : $parser->writeBytes(32, Buffer::int($point->getX(), null, $math))->writeBytes(32, Buffer::int($point->getY(), null, $math));
return $parser->getBuffer();
}
/**
* Attempt to calculate the public key recovery param by trial and error
*
* @param int|string $r
* @param int|string $s
* @param Buffer $messageHash
* @param PublicKey $publicKey
* @return int
* @throws \Exception
*/
public function calcPubKeyRecoveryParam($r, $s, Buffer $messageHash, PublicKey $publicKey)
{
$Q = $publicKey->getPoint();
for ($i = 0; $i < 4; $i++) {
try {
$recover = $this->recover($messageHash, new CompactSignature($this, $r, $s, $i, $publicKey->isCompressed()));
if ($recover->getPoint()->equals($Q)) {
return $i;
}
} catch (\Exception $e) {
continue;
}
}
throw new \Exception('Failed to find valid recovery factor');
}
