/**
* Creates a binary signature with R and S coordinates
*
* @param Signature $signature
*
* @return string
*/
private function createSignatureHash(Signature $signature) : string
{
$length = $this->getSignatureLength();
return pack('H*', sprintf('%s%s', str_pad($this->adapter->decHex($signature->getR()), $length, '0', STR_PAD_LEFT), str_pad($this->adapter->decHex($signature->getS()), $length, '0', STR_PAD_LEFT)));
}
/**
* Encode Signature
*
* This function accepts a signature object, and information about
* the txout being spent, and the relevant key for signing, and
* encodes the signature in DER format.
*
* @param Signature $signature
* @return string
*/
public static function encode_signature(Signature $signature)
{
$math = EccFactory::getAdapter();
$generator = EccFactory::getSecgCurves($math)->generator256k1();
// if S is > half then we substract from N
if (self::check_signature_is_high_s($signature)) {
$n = $generator->getOrder();
$signature = new Signature($signature->getR(), $math->sub($n, $signature->getS()));
}
$rBin = pack("H*", BitcoinLib::hex_encode($signature->getR()));
$sBin = pack("H*", BitcoinLib::hex_encode($signature->getS()));
// Pad R and S if their highest bit is flipped, ie,
// they are negative.
$rt = $rBin[0] & pack('H*', '80');
if (ord($rt) == 128) {
$rBin = pack('H*', '00') . $rBin;
}
$st = $sBin[0] & pack('H*', '80');
if (ord($st) == 128) {
$sBin = pack('H*', '00') . $sBin;
}
$r = bin2hex($rBin);
$s = bin2hex($sBin);
// Create the signature.
$der_sig = '30' . self::_dec_to_bytes(4 + (strlen($r) + strlen($s)) / 2, 1) . '02' . self::pushdata($r) . '02' . self::pushdata($s) . '01';
return $der_sig;
}
/**
* Encode Signature
*
* This function accepts a signature object, and information about
* the txout being spent, and the relevant key for signing, and
* encodes the signature in DER format.
*
* @param Signature $signature
* @return string
*/
public static function encode_signature(Signature $signature)
{
$rBin = pack("H*", BitcoinLib::hex_encode($signature->getR()));
$sBin = pack("H*", BitcoinLib::hex_encode($signature->getS()));
// Pad R and S if their highest bit is flipped, ie,
// they are negative.
$rt = $rBin[0] & pack('H*', '80');
if (ord($rt) == 128) {
$rBin = pack('H*', '00') . $rBin;
}
$st = $sBin[0] & pack('H*', '80');
if (ord($st) == 128) {
$sBin = pack('H*', '00') . $sBin;
}
$r = bin2hex($rBin);
$s = bin2hex($sBin);
// Create the signature.
$der_sig = '30' . self::_dec_to_bytes(4 + (strlen($r) + strlen($s)) / 2, 1) . '02' . self::pushdata($r) . '02' . self::pushdata($s) . '01';
return $der_sig;
}
/**
* encode a message signature
*
* @param Signature $signature
* @param $i
* @param bool $compressed
* @return string
* @throws \Exception
*/
private static function encodeMessageSignature(Signature $signature, $i, $compressed = false)
{
if (!$compressed) {
throw new \Exception("Uncompressed message signing not supported!");
}
$val = $i + 27;
if ($compressed) {
$val += 4;
}
return hex2bin(implode("", [BitcoinLib::hex_encode($val), str_pad(BitcoinLib::hex_encode($signature->getR()), 64, '0', STR_PAD_LEFT), str_pad(BitcoinLib::hex_encode($signature->getS()), 64, '0', STR_PAD_LEFT)]));
}
