Sign transaction hex with PHP library

3

I have a unsigned transaction hex. Now I want to sign this transaction input with my private key in PHP. Bitwasp library looks nice. But I can't find how to sign my transaction. Can you give me any advices?

Transaction Hex

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

Decoded Transaction

{
   "txid":"6c521937d8fa889d71609ebed2e23b694cbca89778c8b8d967167e5a4c9d5b78",
   "size":381,
   "version":1,
   "locktime":0,
   "vin":[
      {
         "txid":"459eee043d30b29c4f9e9b3b55af78f5b4fe4bd818bee49a4b75becd6422ae14",
         "vout":0,
         "scriptSig":{
            "asm":"OP_DUP OP_HASH160 58b6e991b45487df810f4d96d5315da739637f17 OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a91458b6e991b45487df810f4d96d5315da739637f1788ac"
         },
         "sequence":4294967295
      },
      {
         "txid":"621c6b92cc2c68b18fef3a90a3284d1263ea43e0cbce21d9ef6f51747bd215ec",
         "vout":0,
         "scriptSig":{
            "asm":"OP_DUP OP_HASH160 58b6e991b45487df810f4d96d5315da739637f17 OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a91458b6e991b45487df810f4d96d5315da739637f1788ac"
         },
         "sequence":4294967295
      },
      {
         "txid":"92a271c568aea34c3e2661db9b8fc7f0d82d90065db1b6eed1c124146ef77898",
         "vout":0,
         "scriptSig":{
            "asm":"OP_DUP OP_HASH160 58b6e991b45487df810f4d96d5315da739637f17 OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a91458b6e991b45487df810f4d96d5315da739637f1788ac"
         },
         "sequence":4294967295
      },
      {
         "txid":"99c43b144adb6d114180c11f26bc08264c806b355d96a824891ab0831c7facfd",
         "vout":0,
         "scriptSig":{
            "asm":"OP_DUP OP_HASH160 58b6e991b45487df810f4d96d5315da739637f17 OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a91458b6e991b45487df810f4d96d5315da739637f1788ac"
         },
         "sequence":4294967295
      }
   ],
   "vout":[
      {
         "value":5.43e-5,
         "n":0,
         "scriptPubKey":{
            "asm":"OP_DUP OP_HASH160 1485d9d03b41aaa9dca7d70d7f63ff4a0826100e OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a9141485d9d03b41aaa9dca7d70d7f63ff4a0826100e88ac",
            "reqSigs":1,
            "type":"pubkeyhash",
            "addresses":[
               "12sWrxRY7E7Nhmuyjbz4TtGE9jRewGqEZD"
            ]
         }
      },
      {
         "value":0,
         "n":1,
         "scriptPubKey":{
            "asm":"OP_RETURN 246698efc5d81b78ceadf3179316b5eb6cc5c2c347c0b7b42121a94e",
            "hex":"6a1c246698efc5d81b78ceadf3179316b5eb6cc5c2c347c0b7b42121a94e",
            "type":"nulldata"
         }
      },
      {
         "value":6.29e-5,
         "n":2,
         "scriptPubKey":{
            "asm":"OP_DUP OP_HASH160 58b6e991b45487df810f4d96d5315da739637f17 OP_EQUALVERIFY OP_CHECKSIG",
            "hex":"76a91458b6e991b45487df810f4d96d5315da739637f1788ac",
            "reqSigs":1,
            "type":"pubkeyhash",
            "addresses":[
               "1965areciqapsuL2hsia2yKkRLfAsH1smG"
            ]
         }
      }
   ]
}

composer.json

"require": {
    "bitwasp/bitcoin": "v0.0.29.1"
}

sample.php

<?php

require 'vendor/autoload.php';

use BitWasp\Bitcoin\Key\PrivateKeyFactory;
use BitWasp\Bitcoin\Transaction\TransactionFactory;

// Load private key
$private_key = PrivateKeyFactory::fromWif('KEY');

// Transaction from Hex
$transaction = TransactionFactory::fromHex('HEX');

... what should I next...?

Update 1

Solved! Thank you @karimkorun.

composer.json

"require": {
  "bitwasp/bitcoin": "v0.0.29.1"
}

test.php

<?php

require 'vendor/autoload.php';

use BitWasp\Bitcoin\Bitcoin;
use BitWasp\Bitcoin\Script\ScriptFactory;
use BitWasp\Bitcoin\Key\PrivateKeyFactory;
use BitWasp\Bitcoin\Transaction\TransactionFactory;
use BitWasp\Bitcoin\Transaction\Factory\Signer;
use BitWasp\Bitcoin\Transaction\OutPoint;
use BitWasp\Bitcoin\Utxo\Utxo;
use BitWasp\Buffertools\Buffer;
use BitWasp\Bitcoin\Transaction\TransactionOutput;

$hex = '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';
$privateKey = 'XXX';

$tx = TransactionFactory::fromHex($hex);

$utxos = [];
foreach ($tx->getInputs() as $idx => $input) {
    $txid = $input->getOutPoint()->getTxId()->getHex();
    $vout = $input->getOutPoint()->getVout();
    $scriptPubKey = $input->getScript()->getBuffer()->getHex();

    $utxo = new Utxo(new OutPoint(Buffer::hex($txid, 32), $vout), new TransactionOutput(0, ScriptFactory::fromHex($scriptPubKey)));
    array_push($utxos, $utxo);
}

$priv = PrivateKeyFactory::fromWif($privateKey);
$signer = new Signer($tx, Bitcoin::getEcAdapter());

foreach ($utxos as $i => $utxo) {
    $signer->sign($i, $priv, $utxo->getOutput());
}

$signed = $signer->get();
echo $signed->getHex() . PHP_EOL;

Update 2

This is shorter. UTXO objects are not necessary.

$tx = TransactionFactory::fromHex($hex);

$transactionOutputs = [];
foreach ($tx->getInputs() as $idx => $input) {
    $transactionOutput = new TransactionOutput(0, ScriptFactory::fromHex($input->getScript()->getBuffer()->getHex()));
    array_push($transactionOutputs, $transactionOutput);
}

$priv = PrivateKeyFactory::fromWif($privateKey);
$signer = new Signer($tx, Bitcoin::getEcAdapter());

foreach ($transactionOutputs as $idx => $transactionOutput) {
    $signer->sign($idx, $priv, $transactionOutput);
}

$signed = $signer->get();
echo $signed->getHex() . PHP_EOL;

zono

Posted 2016-07-28T05:49:32.583

Reputation: 1 569

There's a folder with examples: https://github.com/Bit-Wasp/bitcoin-php/tree/master/examples check them out as I think your case is covered. On an unrelated note, your transaction input scriptSigs shouldn't have the scriptPubKey's from the outpoints being spent. What way did you generate it?

– karimkorun – 2016-07-30T13:26:58.107

Answers

4

The library has a documentation folder, plus examples to boot! You should always check for these first :-)

As mentioned in the comment above, you should check your transaction creation procedure, as the scriptSig's are not correct for an unsigned transaction - they should just be empty - though the following should work regardless.

First, when signing, you always need the TransactionOutput available.

Since you provided the scriptPubKey inadvertently, I wrote up the following which should work if you substitute your private key. Usually these lookups are done using an API/bitcoind instance, etc.

For non-segwit transactions, you can store just the scriptPubKey (notice I just use 0 for the amount in the TxOut), but for segwit, you have to fill out the amount correctly. 

use BitWasp\Bitcoin\Script\ScriptFactory;
use BitWasp\Bitcoin\Key\PrivateKeyFactory;
use BitWasp\Bitcoin\Transaction\TransactionFactory;
use BitWasp\Bitcoin\Transaction\Factory\Signer;
use BitWasp\Bitcoin\Transaction\OutPoint;
use BitWasp\Bitcoin\Utxo\Utxo;
use BitWasp\Buffertools\Buffer;
use BitWasp\Bitcoin\Transaction\TransactionOutput;

/** @var Utxo[] $utxos */
$utxos = array_map(function (array $utxo) {
    list ($txid, $vout, $scriptPubKey) = $utxo;
    return new Utxo(new OutPoint(Buffer::hex($txid, 32), $vout), new TransactionOutput(0, ScriptFactory::fromHex($scriptPubKey)));
}, [
    ['459eee043d30b29c4f9e9b3b55af78f5b4fe4bd818bee49a4b75becd6422ae14', 0, '76a91458b6e991b45487df810f4d96d5315da739637f1788ac'],
    ['621c6b92cc2c68b18fef3a90a3284d1263ea43e0cbce21d9ef6f51747bd215ec', 0, '76a91458b6e991b45487df810f4d96d5315da739637f1788ac'],
    ['92a271c568aea34c3e2661db9b8fc7f0d82d90065db1b6eed1c124146ef77898', 0, '76a91458b6e991b45487df810f4d96d5315da739637f1788ac'],
    ['99c43b144adb6d114180c11f26bc08264c806b355d96a824891ab0831c7facfd', 0, '76a91458b6e991b45487df810f4d96d5315da739637f1788ac'],
]);

$priv = PrivateKeyFactory::fromWif('yourprivkeyhere');
$hex = '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';
$tx = TransactionFactory::fromHex($hex);
$signer = new Signer($tx);
foreach ($utxos as $i => $utxo) {
    $signer->sign($i, $priv, $utxo->getOutput());
}

$signed = $signer->get();

echo $signed->getHex() . PHP_EOL;

karimkorun

Posted 2016-07-28T05:49:32.583

Reputation: 763

(1) Thank you for your help. I'm trying to implement the code in my environment. (2) The tx is Counterparty's transaction and it was decoded by my own bitcoind. I will let you know the result both (1) and (2) – zono – 2016-08-01T17:17:52.567

Asked: 2016-07-28T05:49:32.583

Viewed: 1 323 times

Active: 2016-08-03T03:05:02.967