non-custodial sends

10 files changed, 127 insertions, 17 deletions

diff --git a/lib/buildtx.js b/lib/buildtx.js
new file mode 100644
index 00000000..351f8081
--- /dev/null
+++ b/lib/buildtx.js
@@ -0,0 +1,76 @@
+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 ({ address, amount, feeRate, user }) => {
+  if (!feeRate) feeRate = (await bc.estimateSmartFee(6)).feerate * SATS;
+  feeRate = Math.round(feeRate / 1000);
+
+  const payments = await db.Payment.findAll({
+    where: {
+      received: true,
+      account_id: user.account_id,
+    } 
+  });
+
+  const utxos = [];
+  for (let i = 0; i < payments.length; i++) {
+    try {
+      utxos.push(...(await axios.get(`${api}/address/${payments[i].address}/utxo`)).data);
+    } catch (e) {
+      l.error("problem fetching utxos", e.message);
+    }
+  } 
+
+  let targets = [
+    {
+      address,
+      value: amount
+    }
+  ];
+
+  let { inputs, outputs, fee } = coinselect(utxos, targets, feeRate);
+
+  if (!inputs || !outputs) {
+    l.info("utxos", amount, feeRate, utxos, inputs, outputs);
+    throw new Error("Failed to create transaction");
+  } 
+
+  let psbt = new bitcoin.Psbt({ network });
+  let total = 0;
+
+  outputs.map(({ address, value }) => {
+    total += value;
+    if (!address) {
+      address =  payments[payments.length - 1].address;
+      change.push(address);
+    } 
+
+    psbt = psbt.addOutput({
+      address,
+      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();
+
+  l.info("returning", { tx: psbt, feeRate });
+  return { tx: psbt, feeRate };
+};
diff --git a/routes/bitcoin/broadcast.js b/routes/bitcoin/broadcast.js
new file mode 100644
index 00000000..c7b134ac
--- /dev/null
+++ b/routes/bitcoin/broadcast.js
@@ -0,0 +1,35 @@
+module.exports = ah(async (req, res) => {
+  try {
+    const { user } = req;
+    let hash = await bc.sendRawTransaction(req.body.tx);
+
+    if (user) {
+      let { account } = user;
+      let payment = await db.Payment.create({
+        ...req.body.payment,
+        hash,
+        amount: -req.body.payment.amount,
+        tip: 0,
+        account_id: account.id,
+        user_id: user.id,
+        rate: app.get("rates")[user.currency],
+        currency: user.currency,
+        confirmed: true,
+        received: false,
+        network: "BTC",
+      });
+
+      account.balance -= payment.amount + payment.fee;
+      await account.save();
+
+      payment = payment.get({ plain: true });
+      payment.account = account.get({ plain: true });
+      emit(user.username, "payment", payment);
+      res.send(payment);
+    } else {
+      res.send(result);
+    }
+  } catch (e) {
+    res.status(500).send(e.message);
+  }
+});
diff --git a/routes/bitcoin/fee.js b/routes/bitcoin/fee.js
index cd99d363..3249004c 100644
--- a/routes/bitcoin/fee.js
+++ b/routes/bitcoin/fee.js
@@ -1,4 +1,4 @@
-const buildTx = ({ address, amount, feeRate }) => {};
+const buildTx = require("../../lib/buildtx");
 
 module.exports = ah(async (req, res) => {
   let { user } = req;
@@ -6,8 +6,12 @@ module.exports = ah(async (req, res) => {
   let tx, fee;
 
   if (user.account.pubkey) {
-    tx = buildTx(req.body);
-    return res.end();
+    try {
+      let psbt = await buildTx({ address, amount, feeRate, user });
+      return res.send(psbt);
+    } catch(e) {
+      return res.status(500).send(e.message);
+    } 
   }
 
   let invoice = await db.Invoice.findOne({
diff --git a/routes/bitcoin/receive.js b/routes/bitcoin/receive.js
index 1c731118..ec120605 100644
--- a/routes/bitcoin/receive.js
+++ b/routes/bitcoin/receive.js
@@ -35,7 +35,7 @@ zmqRawTx.on("message", async (topic, message, sequence) => {
         return;
       }
 
-      if (Object.keys(addresses).includes(address)) {
+      if (Object.keys(addresses).includes(address) && !change.includes(address)) {
         payments.push(hash);
 
         let user = await db.User.findOne({
diff --git a/routes/bitcoin/send.js b/routes/bitcoin/send.js
index 744f8f29..ddf07f3c 100644
--- a/routes/bitcoin/send.js
+++ b/routes/bitcoin/send.js
@@ -1,5 +1,4 @@
 const bitcoin = require("bitcoinjs-lib");
-const reverse = require("buffer-reverse");
 
 module.exports = ah(async (req, res) => {
   let { user } = req;
diff --git a/routes/bitcoin/sweep.js b/routes/bitcoin/sweep.js
index 7d596499..36bd11b5 100644
--- a/routes/bitcoin/sweep.js
+++ b/routes/bitcoin/sweep.js
@@ -9,11 +9,6 @@ const network = prod
   : bitcoin.networks["regtest"];
 
 module.exports = ah(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;
diff --git a/routes/liquid/receive.js b/routes/liquid/receive.js
index 4a00de78..3fe235a6 100644
--- a/routes/liquid/receive.js
+++ b/routes/liquid/receive.js
@@ -1,5 +1,4 @@
 const axios = require("axios");
-const reverse = require("buffer-reverse");
 const zmq = require("zeromq");
 const { Op } = require("sequelize");
 const elements = require("elementsjs-lib");
diff --git a/routes/liquid/send.js b/routes/liquid/send.js
index 5dd7f04e..1d12db30 100644
--- a/routes/liquid/send.js
+++ b/routes/liquid/send.js
@@ -1,5 +1,3 @@
-const reverse = require("buffer-reverse");
-
 module.exports = ah(async (req, res) => {
   let { user } = req;
   let { address, memo, tx } = req.body;
diff --git a/routes/lnurl.js b/routes/lnurl.js
index 7da1d768..c6830ba1 100644
--- a/routes/lnurl.js
+++ b/routes/lnurl.js
@@ -65,10 +65,12 @@ app.post(
   ah(async (req, res, next) => {
     try {
       const { encoded } = req.body.lnurl;
-      const code = await db.Code.findOrCreate({ where: {
-        code: `lnurl:${encoded.substr(-32)}`,
-        text: encoded,
-      }});
+      const code = await db.Code.findOrCreate({
+        where: {
+          code: `lnurl:${encoded.substr(-32)}`,
+          text: encoded,
+        },
+      });
 
       res.send(code);
     } catch (e) {
diff --git a/routes/payments.js b/routes/payments.js
index c46af90e..ca479026 100644
--- a/routes/payments.js
+++ b/routes/payments.js
@@ -8,6 +8,7 @@ const read = require("../lib/read");
 ah(async () => {
   seen = [];
   addresses = {};
+  change = [];
   issuances = {};
 
   const exceptions = [];
@@ -112,6 +113,7 @@ ah(async () => {
 
   if (config.bitcoin) {
     bc = new BitcoinCore(config.bitcoin);
+    app.post("/bitcoin/broadcast", optionalAuth, require("./bitcoin/broadcast"));
     app.get("/bitcoin/generate", auth, require("./bitcoin/generate"));
     app.post("/bitcoin/sweep", auth, require("./bitcoin/sweep"));
     app.post("/bitcoin/fee", auth, require("./bitcoin/fee"));