Creating transaction for Bitcoin Cash

[Vasiliy-Bondarenko]

Hello.

I'm constructing transaction for Bitcoin Cash using this example
But when i try to broadcast it, I get an error:

error code: -26
error message:
16: mandatory-script-verify-flag-failed (Script failed an OP_EQUALVERIFY operation)

What's wrong? How to debug it?

Transaction in hex:

0100000001367ff84870b1511912cbe18c66dd72e15585f402a47bfb89abd3a743ca9a665c000000006b483045022100f64eff52538c376c0316c525f75ef1d68486c77542c68d53fe52d5bc06c9c67c0220513033f3315175a898cab7a2e0a39a89a2d61016e4c0c81d08b7430567a7cebd01210335bc2d792f974a4e8952b93e0ee1e6b84e93c662f97bec9566265664763f64b10100000001071b0000000000001976a914eb5808ea4850a18bd03a933e92a2ac5c7873020188ac00000000

[Vasiliy-Bondarenko]

i use this network:

class NetworkFactory extends \BitWasp\Bitcoin\Network\NetworkFactory
{
    /**
     * @return NetworkInterface
     * @throws \Exception
     */
    public static function bitcoinCash(): NetworkInterface
    {
        return self::create('00', '05', '80')
                   ->setHDPubByte('0488b21e')
                   ->setHDPrivByte('0488ade4')
                   ->setNetMagicBytes('d9b4bef9')
                // ->setSegwitBech32Prefix("bc") # this needs to be removed to safely use bitcoin cash
            ;
    }
}

[afk11]

My first guess is that you used the wrong txOut because when signed the public key doesn't match the pubKeyHash in the script:
DUP HASH160 [hash] EQUALVERIFY CHECKSIG

Double check that the txout script you are using is the correct one for that txid,vout. The signer will detect if you are signing a pubKeyHash script with the wrong key. maybe it's the right key for the scriptPubKey, but you are using the wrong scriptPubKey for that output?

Btw here's an example, you have to tell the Signer it's redeeming bitcoin cash (not mentioned in docs)
https://github.com/Bit-Wasp/bitcoin-php/blob/master/tests/Transaction/Factory/SignerTest.php#L399

[Vasiliy-Bondarenko]

Ok. Getting there...
I'm trying to rewrite the code using the test as an example.

bitcoin-php/src/Transaction/Factory/Signer.php

Line 88 in 0e57762

public function redeemBitcoinCash()

- this method has different signature in current release then in master branch. Which one is correct? :)

[Vasiliy-Bondarenko]

Thanks for the help, but still not working... :) Even with the code from the test you mentioned.
Below in the code it's real address and it's wif.
I'm working on last 0.0.34.2 release.
I get the same error as before then i broadcasting generated transaction.

Transaction https://blockdozer.com/insight/address/1APR9o8f7fnSKB3WsQ792xcHdhNEPt79Lo
I need to spend from n=1 address 1APR9o8f7fnSKB3WsQ792xcHdhNEPt79Lo

       $network = NetworkFactory::bitcoinCash();

        $wif = "L1X77tAPT3YtTrvXKoQE6zuFD4JKg8x2zpVAoh1Zx8awmtfv8w1w";

        $keyPair = PrivateKeyFactory::fromWif($wif, null, $network);

        $value = 7205;
        $txid = "35d5d41aa012f76ca9faa4696af94a8bf417be7735ae269142927b3b349281e9";
        $vout = 1;
        $spk = ScriptFactory::scriptPubKey()->payToPubKey($keyPair->getPublicKey());

        $dest = AddressFactory::fromString("1NTPFr8MhALzHDKJ9xs8oxPyANLb1hBzJT", $network)->getScriptPubKey();
        $txb = (new TxBuilder())
            ->version(2)
            ->input($txid, $vout)
            ->output($value, $dest)
        ;
        $txs = new Signer($txb->get());
        $txs->redeemBitcoinCash(true);
        $hashType = SigHash::BITCOINCASH | SigHash::ALL;
        $input = $txs->input(0, new TransactionOutput($value, $spk));
        $input->sign($keyPair, $hashType);
        $tx = $txs->get();

        var_dump($tx->getHex());
        exit;

outputs:

0200000001e98192343b7b92429126ae3577be17f48b4af96a69a4faa96cf712a01ad4d5350100000049483045022100b4e68844ff37e00da389bd22496a1c3ae3a6daa3f1182c333a062ad68f56a248022005c42361a3a81809ee158dafddf1fdd5307c268ab8e2841d2e9742dc658bec6941ffffffff01251c0000000000001976a914eb5808ea4850a18bd03a933e92a2ac5c7873020188ac00000000

I'm lost... :)

[Vasiliy-Bondarenko]

looks i solved the issue with hash by modifying script like this:

$spk = ScriptFactory::scriptPubKey()->payToPubKeyHash($keyPair->getPublicKey()->getPubKeyHash());

no i've come to the next error... the code looks like:

        $network = NetworkFactory::bitcoinCash();

        $wif = "L3xeChXH329KhyppGkpHtDJFV7j4dr7uA5GZ9cg1FREf2aopzqzB";

        $keyPair = PrivateKeyFactory::fromWif($wif, null, $network);

        $value = 7205;
        $txid = "35d5d41aa012f76ca9faa4696af94a8bf417be7735ae269142927b3b349281e9";
        $vout = 1;
        $spk = ScriptFactory::scriptPubKey()->payToPubKeyHash($keyPair->getPublicKey()->getPubKeyHash());

        $dest = AddressFactory::fromString("1NTPFr8MhALzHDKJ9xs8oxPyANLb1hBzJT", $network)->getScriptPubKey();

        $txb = (new TxBuilder())
            ->version(2)
            ->input($txid, $vout)
            ->output($value, $dest);

        $txs = new Signer($txb->get());
        $txs->redeemBitcoinCash(true);

        $hashType = SigHash::BITCOINCASH | SigHash::ALL;

        $input = $txs->input(0, new TransactionOutput($value, $spk));
        $input->sign($keyPair, $hashType);

        $tx = $txs->get();

        var_dump($tx->getHex());
        exit;

outputs:

0200000001e98192343b7b92429126ae3577be17f48b4af96a69a4faa96cf712a01ad4d535010000006a47304402201eb46e2605495fc59bd5811c8e2e20adc8e73d5235e87ad5bad3efd9aeacc1ee0220166607e7ad9aa74306e91ddad4b51fd85df6091440eace104a2d35d8077961bf41210245378ef9f3d4761ec934f044e85dcce0ab19cb1b244c794d32032de5dd523dc5ffffffff01251c0000000000001976a914eb5808ea4850a18bd03a933e92a2ac5c7873020188ac00000000

and errors out while broadcasting with:

16: mandatory-script-verify-flag-failed (Signature must be zero for failed CHECK(MULTI)SIG operation)

[Vasiliy-Bondarenko]

Problem resolved. My fault. I had an error with keys for derived addresses.
Thanks for the help.

[afk11]

Sorry, was offline this week! Glad to see you got the problem sorted! Generally you should just derive and save the scriptpubkey & address (+ redeem/witness scripts) in a database. It's implied that before you received payment, you took a private key, derived the public key and scriptPubKey and address. Saving those, and then finding the txid/vout/value is normally the way to go.

If you have just address you received funds on, you can decode it and use getScriptPubKey()

[Vasiliy-Bondarenko]

i'm saving only address and sequence number in DB. so i can track blocks for my addresses and recover all i need to spend transaction using sequence number from master private key. is it ok? or i can have a problem down the road?

[afk11]

Cool That's fine - AddressFactory::fromString($addr)->getScriptPubKey(); will give it back to you in the most direct way when you want to sign!