private key sweep

1 files changed, 59 insertions, 0 deletions

diff --git a/routes/bitcoin/sweep.js b/routes/bitcoin/sweep.js
new file mode 100644
index 00000000..37efb73f
--- /dev/null
+++ b/routes/bitcoin/sweep.js
@@ -0,0 +1,59 @@
+const axios = require("axios");
+const bitcoin = require("bitcoinjs-lib");
+const coinselect = require("coinselect");
+const split = require("coinselect/split");
+const api = prod ? "https://blockstream.info/api" : "http://localhost:3002";
+const SATS = 100000000;
+const network = prod
+  ? bitcoin.networks["bitcoin"]
+  : bitcoin.networks["regtest"];
+
+module.exports = async (req, res) => {
+  let ecpair = bitcoin.ECPair.fromWIF('cVosbTBiXp7LYSiGVRZfZnrEjpao4X4CUTG7Ze21XM3zFTLPCMvk', network);
+
+  let { address: from, amount, feeRate, target } = req.body;
+  let utxos;
+  if (!feeRate)
+    feeRate = ((await bc.estimateSmartFee(6)).feerate * SATS);
+  feeRate = Math.round(feeRate / 1000);
+  l.info("sweeping", req.user.username, from, amount, feeRate);
+  try {
+    ({ data: utxos } = await axios.get(`${api}/address/${from}/utxo`));
+  } catch (e) {
+    l.error("problem fetching utxos", e.message);
+  }
+
+  let targets = [
+    {
+      address: target,
+      value: amount
+    }
+  ];
+
+  let { inputs, outputs, fee } = coinselect(utxos, targets, feeRate);
+
+  if (!inputs || !outputs) return res.status(500).send("Unable to construct sweep transaction, try a lower fee rate?");
+
+  let psbt = new bitcoin.Psbt({ network });
+
+  outputs.map(({ address, value }) => {
+    psbt = psbt.addOutput({
+      address: address || from,
+      value
+    })
+  });
+
+  for (let i = 0; i < inputs.length; i++) {
+    let { txid, vout } = inputs[i];
+    let nonWitnessUtxo = Buffer.from(await bc.getRawTransaction(txid), 'hex');
+    psbt = psbt.addInput({
+      hash: txid,
+      index: vout,
+      nonWitnessUtxo,
+    });
+  }
+
+  feeRate = Math.round(feeRate * 1000);
+  psbt = psbt.toBase64();
+  res.send({ feeRate, psbt });
+};