Bitcoinjs-lib: how can i sign raw serialized transaction

[sinanouri]

i generated raw unsigned dogecoin transaction using third party api and now i got this:

0100000001eeb5498b1adbf77d39f1f55b3cd943b9da9f192e444504a968e3b4eb02bb4a850100000000ffffffff010052230b390000001976a914c09113adb3c0dffce410382e0ef2e04d3617047d88ac00000000

i am doing like this but it is not working:

var bitcoin = require('bitcoinjs-lib')
var bitcoin_message = require('bitcoinjs-message')
var DOGECOIN =   {
    messagePrefix: '\x19Dogecoin Signed Message:\n',
    bip32: {
        public: 0x02facafd,
        private: 0x02fac398
    },
    pubKeyHash: 0x1e,
    scriptHash: 0x16,
    wif: 0x9e
}
var keyPair = bitcoin.ECPair.fromWIF(Buffer.from('__myWIF__'), DOGECOIN);
var privateKey = keyPair.__d;
var message = '0100000001eeb5498b1adbf77d39f1f55b3cd943b9da9f192e444504a968e3b4eb02bb4a850100000000ffffffff010052230b390000001976a914c09113adb3c0dffce410382e0ef2e04d3617047d88ac00000000';

var signature = bitcoin_message.sign(message, privateKey, keyPair.compressed);
console.log(signature.toString('base64'));

[junderw]

1. If your API is using raw serialized transactions and not PSBT, it's a very old API. But seeing as this is for Dogecoin, which is based on an old version of bitcoin, and dogecoin has almost no developers to keep it up to date with the latest updates, it would probably be best to use TransactionBuilder.
2. Using Transaction's fromHex and then TransactionBuilder's fromTransaction will allow you to create a TransactionBuilder and sign the inputs using that.
3. Examples: https://github.com/bitcoinjs/bitcoinjs-lib/blob/6c08a0be40a4d382f64b7385531407372a7e3b91/test/integration/transactions.spec.ts

[junderw]

const bitcoin = require('bitcoinjs-lib')
const DOGECOIN = {
    messagePrefix: '\x19Dogecoin Signed Message:\n',
    bip32: {
        public: 0x02facafd,
        private: 0x02fac398
    },
    pubKeyHash: 0x1e,
    scriptHash: 0x16,
    wif: 0x9e
}

// myWif is a string, fromWIF takes a string not a Buffer
const keyPair = bitcoin.ECPair.fromWIF('__myWIF__', DOGECOIN);

const txHex = '0100000001eeb5498b1adbf77d39f1f55b3cd943b9da9f192e444504a968e3b4eb02bb4a850100000000ffffffff010052230b390000001976a914c09113adb3c0dffce410382e0ef2e04d3617047d88ac00000000';
const tx = bitcoin.Transaction.fromHex(txHex);
const txb = bitcoin.TransactionBuilder.fromTransaction(tx, DOGECOIN);

// This assumes all inputs are spending utxos sent to the same Dogecoin P2PKH address (starts with D)
for (let i = 0; i < tx.ins.length; i++) {
  txb.sign(i, keyPair);
}

const signedTxHex = txb.build().toHex();
// Broadcast this signed raw transaction
console.log(signedTxHex)