relay wip

relay/relay.js

@@ -0,0 +1,44 @@
+let bigInt = require('snarkjs/src/bigint');
+
+require('dotenv').config();
+const { AMOUNT, MERKLE_TREE_HEIGHT, EMPTY_ELEMENT } = process.env;
+
+const express = require('express');
+const app = express();
+app.use(express.json());
+
+const Web3 = require('web3');
+web3 = new Web3('http://localhost:8545', null, {transactionConfirmationBlocks: 1});
+contractJson = require('../build/contracts/Mixer.json');
+let netId = 42;
+mixer = new web3.eth.Contract(contractJson.abi, contractJson.networks[netId].address);
+
+function getMinimumFee() {
+  // todo calc acceptable fee
+  return 1e16;
+}
+
+app.post('/deposit', async (req, resp) => {
+  let proof = req.body;
+  if (!(proof.pi_a && proof.pi_b && proof.pi_c && proof.publicSignals)) { // check that it's kinda well formed
+    resp.status(400).end();
+  }
+
+  if (bigInt(proof.publicSignals[3]) < getMinimumFee()) {
+    resp.status(403).send("Fee is too low");
+  }
+
+  if (!utils.snarkVerify(proof)) {
+    resp.status(403).send("Invalid snark proof");
+  }
+
+  try {
+    let receipt = await mixer.withdraw(proof.pi_a, proof.pi_b, proof.pi_b, proof.publicSignals);
+    console.log(receipt);
+    resp.send({transaction: receipt.transactionHash})
+  } catch (e) {
+    console.log(e);
+    resp.status(400).send("Transaction was reverted");
+  }
+});
+app.listen(3000);