Updated sign transaction to use bitcoinjs-lib

CHANGELOG.md

@@ -74,4 +74,5 @@
 
 ### 2.0.5 (2024-01-23)
 
-- Replaced blockcyper api with sochain api to fetch fees in satoshi
+- Replaced blockcyper api with sochain api to fetch fees in satoshi
+- Updated sign transaction to use bitcoinjs-lib

src/helper/calculateFeeAndInput.js

@@ -17,12 +17,11 @@ async function getTransactionSize(URL, headers){
     let inputs = [];
     utxos.data.data.outputs.forEach(async (element) => {
         let utxo = {};
-        utxo.satoshis = sb.toSatoshi(parseFloat(element.value));
-        utxo.script = element.script;
-        utxo.address = element.address;
-        utxo.txId = element.hash;
-        utxo.outputIndex = element.index;
-        totalAmountAvailable += utxo.satoshis;
+        utxo.value = sb.toSatoshi(parseFloat(element.value));
+        utxo.scriptPubKey = element.script;
+        utxo.txid = element.hash;
+        utxo.vout = element.index;
+        totalAmountAvailable += utxo.value;
         inputCount += 1;
         inputs.push(utxo);
     });

src/helper/signTransaction.js

@@ -1,37 +1,50 @@
-const bitcore = require("bitcore-lib")
+const bitcoin = require("bitcoinjs-lib")
 
 const {getFeeAndInput} = require('./calculateFeeAndInput')
 
-async function signTransaction(from, to, amountToSend, URL, privateKey, satPerByte, headers) {
-
-    const transaction = new bitcore.Transaction();
+async function signTransaction(from, to, amountToSend, URL, privateKey, satPerByte, headers, network) {
+    
+    const psbt = new bitcoin.Psbt({ network: network }) 
 
     const { totalAmountAvailable, inputs, fee } = await getFeeAndInput(URL, satPerByte, headers)
 
     if (totalAmountAvailable - amountToSend - fee < 0) {
         throw new Error("Balance is too low for this transaction");
     }
 
-    //Set transaction input
-    transaction.from(inputs);
-
-    // set the recieving address and the amount to send
-    transaction.to(to, Math.floor(amountToSend));
-
-    // Set change address - Address to receive the left over funds after transfer
-    transaction.change(from);
+    for (const unspentOutput of inputs) {
+        psbt.addInput({
+            hash: unspentOutput.txid,
+            index: unspentOutput.vout,
+            witnessUtxo: {
+                script: Buffer.from(unspentOutput.scriptPubKey, 'hex'),
+                value: unspentOutput.value // value in satoshi
+            },
+        })
+    }
 
-    //manually set transaction fees: 20 satoshis per byte
-    transaction.fee(fee);
+    psbt.addOutput({address: to, value: amountToSend});
 
-    // Sign transaction with your private key
-    transaction.sign(privateKey);
+    const change = totalAmountAvailable - amountToSend - fee
+    psbt.addOutput({address: from, value: change});
+
+    for (let i = 0; i < inputs.length; i++) {
+        psbt.signInput(i, bitcoin.ECPair.fromWIF(privateKey, bitcoin.networks.testnet))
+    }
 
-    // serialize Transactions
-    const serializedTransaction = transaction.serialize();
+    const isValid = psbt.validateSignaturesOfAllInputs()
 
-    return serializedTransaction;
+    if (isValid) {
+        psbt.finalizeAllInputs()
+        // signed transaction hex
+        const transaction = psbt.extractTransaction()
+        const signedTransaction = transaction.toHex()
+        const transactionId = transaction.getId()
 
+        return signedTransaction
+    }
+
 }
 
+
 module.exports = signTransaction

src/index.js

@@ -92,7 +92,7 @@ class KeyringController {
     const headers = { "API-KEY": SOCHAIN_API_KEY}
 
     try {
-      const signedTransaction = await helpers.signTransaction(from, to, amount, URL, privateKey, satPerByte, headers)
+      const signedTransaction = await helpers.signTransaction(from, to, amount, URL, privateKey, satPerByte, headers, network)
       return { signedTransaction };
     } catch (err) {
       throw err