79 lines
2.5 KiB
JavaScript
79 lines
2.5 KiB
JavaScript
const { numberToHex, toWei, toHex } = require('web3-utils')
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const Web3 = require('web3')
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const express = require('express')
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const app = express()
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app.use(express.json())
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app.use(function(req, res, next) {
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res.header('Access-Control-Allow-Origin', '*') // update to match the domain you will make the request from
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res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
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next()
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})
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const { netId, rpcUrl, privateKey, mixerAddress, defaultGasPrice } = require('./config')
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const { fetchGasPrice, isValidProof } = require('./utils')
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const web3 = new Web3(rpcUrl, null, { transactionConfirmationBlocks: 1 })
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const account = web3.eth.accounts.privateKeyToAccount('0x' + privateKey)
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web3.eth.accounts.wallet.add('0x' + privateKey)
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web3.eth.defaultAccount = account.address
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const mixerABI = require('./mixerABI.json')
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const mixer = new web3.eth.Contract(mixerABI, mixerAddress)
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const gasPrices = { fast: defaultGasPrice }
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app.get('/', function (req, res) {
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// just for testing purposes
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res.send(`Tornado mixer relayer. Gas Price is ${JSON.stringify(gasPrices)}`)
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})
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app.post('/relay', async (req, resp) => {
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const { valid , reason } = isValidProof(req.body)
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if (!valid) {
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console.log('Proof is invalid:', reason)
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return resp.status(400).send('Proof is invalid')
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}
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let { pi_a, pi_b, pi_c, publicSignals } = req.body
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// TODO
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// if (bigInt(proof.publicSignals[3]) < getMinimumFee()) {
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// resp.status(403).send('Fee is too low')
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// }
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try {
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const nullifier = publicSignals[1]
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const isSpent = await mixer.methods.isSpent(nullifier).call()
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if (isSpent) {
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throw new Error('The note has been spent')
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}
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const root = publicSignals[0]
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const isKnownRoot = await mixer.methods.isKnownRoot(root).call()
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if (!isKnownRoot) {
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throw new Error('The merkle root is too old or invalid')
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}
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const gas = await mixer.methods.withdraw(pi_a, pi_b, pi_c, publicSignals).estimateGas()
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const result = mixer.methods.withdraw(pi_a, pi_b, pi_c, publicSignals).send({
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gas: numberToHex(gas + 50000),
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gasPrice: toHex(toWei(gasPrices.fast.toString(), 'gwei')),
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// TODO: nonce
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})
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result.once('transactionHash', function(hash){
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resp.json({ txHash: hash })
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}).on('error', function(e){
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console.log(e)
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resp.status(400).send('Proof is malformed')
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})
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} catch (e) {
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console.log(e)
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resp.status(400).send('Proof is malformed or spent')
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}
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})
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app.listen(8000)
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if (netId === 1) {
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fetchGasPrice({ gasPrices })
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console.log('Gas price oracle started.')
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}
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