function isMessageSignatureValid($address, $signature, $message)
{
$address = base58check_decode($address);
if (strlen($address) != 21 || $address[0] != "") {
throw new InvalidArgumentException('Invalid Bitcoin address.');
}
$derivedAddress = getVerifiedAddress160Bin($signature, $message);
$derivedAddress = "" . $derivedAddress;
return $address === $derivedAddress;
}
public function buildDataAddr($toaddr, $currency, $amount)
{
$decoded = base58check_decode($toaddr);
$seqnum = hexdec(bin2hex($decoded[1])) - 1;
if ($seqnum < 0) {
$seqnum = $seqnum + 256;
}
$datahex = dechex($seqnum);
// seqence number
$datahex = $datahex . $this->int32ToHexLittle(0);
// tx type
$datahex = $datahex . $this->int32ToHexLittle($currency);
// currency id
$datahex = $datahex . $this->int64ToHexLittle($amount);
// amount
$datahex = $datahex . "000000";
$encoded = base58check_encode(hex2bin($datahex));
return $encoded;
}
function isMessageSignatureValid($address, $signature, $message)
{
// curve definition
// http://www.secg.org/download/aid-784/sec2-v2.pdf
static $secp256k1 = null;
static $secp256k1_G = null;
$secp256k1 == null && ($secp256k1 = new CurveFp('0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F', '0', '7'));
$secp256k1_G == null && ($secp256k1_G = new Point($secp256k1, '0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798', '0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8', '0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141'));
// extract parameters
$address = base58check_decode($address);
if (strlen($address) != 21 || $address[0] != "") {
throw new InvalidArgumentException('invalid Bitcoin address');
}
$signature = base64_decode($signature, true);
if ($signature === false) {
throw new InvalidArgumentException('invalid base64 signature');
}
if (strlen($signature) != 65) {
throw new InvalidArgumentException('invalid signature length');
}
$recoveryFlags = ord($signature[0]) - 27;
if ($recoveryFlags < 0 || $recoveryFlags > 7) {
throw new InvalidArgumentException('invalid signature type');
}
$isCompressed = ($recoveryFlags & 4) != 0;
// hash message, recover key
$messageHash = hash('sha256', hash('sha256', "Bitcoin Signed Message:\n" . numToVarIntString(strlen($message)) . $message, true), true);
$pubkey = recoverPubKey(bin2gmp(substr($signature, 1, 32)), bin2gmp(substr($signature, 33, 32)), bin2gmp($messageHash), $recoveryFlags, $secp256k1_G);
if ($pubkey === false) {
throw new InvalidArgumentException('unable to recover key');
}
$point = $pubkey->getPoint();
// see that the key we recovered is for the address given
if (!$isCompressed) {
$pubBinStr = "" . str_pad(gmp2bin($point->getX()), 32, "", STR_PAD_LEFT) . str_pad(gmp2bin($point->getY()), 32, "", STR_PAD_LEFT);
} else {
$pubBinStr = (isBignumEven($point->getY()) ? "" : "") . str_pad(gmp2bin($point->getX()), 32, "", STR_PAD_LEFT);
}
$derivedAddress = "" . hash('ripemd160', hash('sha256', $pubBinStr, true), true);
return $address === $derivedAddress;
}
protected function addressToRipemd160($address)
{
return bin2hex(substr(base58check_decode($address), 1, 20));
}
