refactor + coingecko

abis/ETHDAIOracle.json

@@ -1,17 +0,0 @@
-[
-    {
-      "constant": true,
-      "inputs": [],
-      "name": "getMedianPrice",
-      "outputs": [
-        {
-          "internalType": "uint256",
-          "name": "",
-          "type": "uint256"
-        }
-      ],
-      "payable": false,
-      "stateMutability": "view",
-      "type": "function"
-    }
-]

config.js

@@ -14,6 +14,7 @@ module.exports = {
   } ],
   defaultGasPrice: 2,
   gasOracleUrls: ['https://www.etherchain.org/api/gasPriceOracle', 'https://gasprice.poa.network/'],
-  ethdaiAddress: '0x7Ef645705cb7D401C5CD91a395cfcc3Db3C93689',
+  port: process.env.APP_PORT,
-  port: process.env.APP_PORT
+  //dai
+  tokens: ['0x6b175474e89094c44da98b954eedeac495271d0f']
 }

package.json

@@ -4,13 +4,14 @@
   "description": "Relayer for Tornado mixer. https://tornado.cash",
   "main": "index.js",
   "scripts": {
-    "start": "node index.js",
+    "start": "node src/index.js",
     "eslint": "npx eslint --ignore-path .gitignore .",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
-  "author": "Alexey Pertsev <alexey@peppersec.com> (https://peppersec.com)",
+  "author": "tornado.cash",
   "license": "MIT",
   "dependencies": {
+    "coingecko-api": "^1.0.6",
     "dotenv": "^8.2.0",
     "express": "^4.17.1",
     "node-fetch": "^2.6.0",

src/Fetcher.js

@@ -0,0 +1,69 @@
+const CoinGecko = require('coingecko-api') 
+const fetch = require('node-fetch')
+const { gasOracleUrls, defaultGasPrice } = require('../config')
+const { toWei } = require('web3-utils')
+const { tokens } = require('../config')
+ 
+
+class Fetcher {
+  constructor(web3) {
+    this.web3 = web3
+    this.ethPrices = {
+      dai: '6700000000000000' // 0.0067
+    }
+    this.gasPrices = {
+      fast: defaultGasPrice
+    }
+  }
+  async fetchPrices() {
+    try {
+      const CoinGeckoClient = new CoinGecko()
+      const price = await CoinGeckoClient.simple.fetchTokenPrice({
+        contract_addresses: tokens,
+        vs_currencies: 'eth',
+        assetPlatform: 'ethereum'
+      })
+      const addressToSymbol = {
+        '0x6b175474e89094c44da98b954eedeac495271d0f': 'dai'
+      }
+      this.ethPrices = Object.entries(price.data).reduce((acc, token) => {
+        if (token[1].eth) {
+          acc[addressToSymbol[token[0]]] = toWei(token[1].eth.toString())
+        }
+        return acc
+      }, {})
+      setTimeout(() => this.fetchPrices(), 1000 * 30)
+    } catch(e) {
+      setTimeout(() => this.fetchPrices(), 1000 * 30)
+    }
+  }
+  async fetchGasPrice({ oracleIndex = 0 } = {}) {
+    oracleIndex = (oracleIndex + 1) % gasOracleUrls.length
+    try {
+      const response = await fetch(gasOracleUrls[oracleIndex])
+      if (response.status === 200) {
+        const json = await response.json()
+  
+        if (json.slow) {
+          this.gasPrices.low = Number(json.slow)
+        }
+        if (json.safeLow) {
+          this.gasPrices.low = Number(json.safeLow)
+        }
+        if (json.standard) {
+          this.gasPrices.standard = Number(json.standard)
+        }
+        if (json.fast) {
+          this.gasPrices.fast = Number(json.fast)
+        }
+      } else {
+        throw Error('Fetch gasPrice failed')
+      }
+      setTimeout(() => this.fetchGasPrice({ oracleIndex }), 15000)
+    } catch (e) {
+      setTimeout(() => this.fetchGasPrice({ oracleIndex }), 15000)
+    }
+  }
+}
+
+module.exports = Fetcher

src/index.js

@@ -0,0 +1,49 @@
+const express = require('express')
+const { netId, mixers, port } = require('../config')
+const relayController = require('./relayController')
+const { fetcher, web3 } = require('./instances')
+
+const app = express()
+app.use(express.json())
+
+app.use((err, req, res, next) => {
+  if (err) {
+    console.log('Invalid Request data')
+    res.send('Invalid Request data')
+  } else {
+    next()
+  }
+})
+
+app.use(function(req, res, next) {
+  res.header('Access-Control-Allow-Origin', '*')
+  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
+  next()
+})
+
+app.get('/', function (req, res) {
+  // just for testing purposes
+  res.send('This is <a href=https://tornado.cash>tornado.cash</a> Relayer service. Check the /status for settings')
+})
+
+app.get('/status', function (req, res) {
+  const { ethPrices, gasPrices } = fetcher
+  res.json({ relayerAddress: web3.eth.defaultAccount, mixers, gasPrices, netId, ethPrices })
+})
+
+app.post('/relay', relayController)
+
+app.listen(port || 8000)
+
+if (Number(netId) === 1) {
+  console.log('Gas price oracle started.')
+  fetcher.fetchGasPrice()
+  fetcher.fetchPrices()
+}
+
+console.log('Relayer started on port', port || 8000)
+console.log(`relayerAddress: ${web3.eth.defaultAccount}`)
+console.log(`mixers: ${JSON.stringify(mixers)}`)
+console.log(`gasPrices: ${JSON.stringify(fetcher.gasPrices)}`)
+console.log(`netId: ${netId}`)
+console.log(`ethPrices: ${JSON.stringify(fetcher.ethPrices)}`)

src/instances.js

@@ -0,0 +1,8 @@
+const Fetcher = require('./Fetcher')
+const web3 = require('./setupWeb3')
+const fetcher = new Fetcher(web3)
+
+module.exports = {
+  fetcher,
+  web3
+}

src/relayController.js

@@ -1,47 +1,15 @@
 const { numberToHex, toWei, toHex, toBN, toChecksumAddress } = require('web3-utils')
-const { netId, rpcUrl, privateKey, mixers, defaultGasPrice, port } = require('./config')
+const mixerABI = require('../abis/mixerABI.json') 
-const { fetchGasPrice, isValidProof, isValidArgs, fetchDAIprice, isKnownContract, isEnoughFee } = require('./utils')
+const { 
-const Web3 = require('web3')
+  isValidProof, isValidArgs, isKnownContract, isEnoughFee
-const express = require('express')
+} = require('./utils')
 
-const app = express()
+const { web3, fetcher } = require('./instances')
-app.use(express.json())
 
-app.use((err, req, res, next) => {
+async function relay (req, resp) {
-  if (err) {
-    console.log('Invalid Request data')
-    res.send('Invalid Request data')
-  } else {
-    next()
-  }
-})
-
-app.use(function(req, res, next) {
-  res.header('Access-Control-Allow-Origin', '*')
-  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
-  next()
-})
-
-const web3 = new Web3(rpcUrl, null, { transactionConfirmationBlocks: 1 })
-const account = web3.eth.accounts.privateKeyToAccount('0x' + privateKey)
-web3.eth.accounts.wallet.add('0x' + privateKey)
-web3.eth.defaultAccount = account.address
-
-const mixerABI = require('./abis/mixerABI.json') 
-const gasPrices = { fast: defaultGasPrice }
-const ethPriceInDai = toWei('200')
-
-app.get('/', function (req, res) {
-  // just for testing purposes
-  res.send('This is <a href=https://tornado.cash>tornado.cash</a> Relayer service. Check the /status for settings')
-})
-
-app.get('/status', function (req, res) {
-  res.json({ relayerAddress: web3.eth.defaultAccount, mixers, gasPrices, netId, ethPriceInDai })
-})
-
-app.post('/relay', async (req, resp) => {
   const { proof, args, contract } = req.body
+  console.log(proof, args, contract)
+  const gasPrices = fetcher.gasPrices
   let { valid , reason } = isValidProof(proof)
   if (!valid) {
     console.log('Proof is invalid:', reason)
@@ -69,7 +37,7 @@ app.post('/relay', async (req, resp) => {
     toBN(args[4]),
     toBN(args[5])
   ]
-
+  console.log('root, nullifierHash, recipient, relayer, fee, refund', fee.toString(), refund)
   if (currency === 'eth' && !refund.isZero()) {
     return resp.status(400).json({ error: 'Cannot send refund for eth currency.' })
   }
@@ -105,8 +73,8 @@ app.post('/relay', async (req, resp) => {
     })
 
     gas += 50000
-
+    const ethPrices = fetcher.ethPrices
-    const { isEnough, reason } = isEnoughFee({ gas, gasPrices, currency, refund, ethPriceInDai, fee })
+    const { isEnough, reason } = isEnoughFee({ gas, gasPrices, currency, refund, ethPrices, fee })
     if (!isEnough) {
       console.log(`Wrong fee: ${reason}`)
       return resp.status(400).json({ error: reason })
@@ -130,19 +98,6 @@ app.post('/relay', async (req, resp) => {
     console.log(e)
     return resp.status(400).json({ error: 'Proof is malformed or spent.' })
   }
-})
-
-app.listen(port || 8000)
-
-if (Number(netId) === 1) {
-  fetchGasPrice({ gasPrices })
-  fetchDAIprice({ ethPriceInDai, web3 })
-  console.log('Gas price oracle started.')
 }
 
-console.log('Relayer started on port', port || 8000)
+module.exports = relay
-console.log(`relayerAddress: ${web3.eth.defaultAccount}`)
-console.log(`mixers: ${JSON.stringify(mixers)}`)
-console.log(`gasPrices: ${JSON.stringify(gasPrices)}`)
-console.log(`netId: ${netId}`)
-console.log(`ethPriceInDai: ${ethPriceInDai}`)

src/setupWeb3.js

@@ -0,0 +1,16 @@
+const Web3 = require('web3')
+const { rpcUrl, privateKey } = require('../config')
+
+function setup() {
+  try {
+    const web3 = new Web3(rpcUrl, null, { transactionConfirmationBlocks: 1 })
+    const account = web3.eth.accounts.privateKeyToAccount('0x' + privateKey)
+    web3.eth.accounts.wallet.add('0x' + privateKey)
+    web3.eth.defaultAccount = account.address
+    return web3
+  } catch(e) {
+    console.error('web3 failed')
+  }
+}
+const web3 = setup()
+module.exports = web3

src/utils.js

@@ -1,46 +1,5 @@
-const fetch = require('node-fetch')
+const { isHexStrict, toBN, toWei } = require('web3-utils')
-const { isHexStrict, hexToNumberString, toBN, toWei } = require('web3-utils')
+const { mixers } = require('../config')
-const { gasOracleUrls, ethdaiAddress, mixers } = require('./config')
-const oracleABI = require('./abis/ETHDAIOracle.json')
-
-async function fetchGasPrice({ gasPrices, oracleIndex = 0 }) {
-  oracleIndex = (oracleIndex + 1) % gasOracleUrls.length
-  try {
-    const response = await fetch(gasOracleUrls[oracleIndex])
-    if (response.status === 200) {
-      const json = await response.json()
-
-      if (json.slow) {
-        gasPrices.low = Number(json.slow)
-      }
-      if (json.safeLow) {
-        gasPrices.low = Number(json.safeLow)
-      }
-      if (json.standard) {
-        gasPrices.standard = Number(json.standard)
-      }
-      if (json.fast) {
-        gasPrices.fast = Number(json.fast)
-      }
-    } else {
-      throw Error('Fetch gasPrice failed')
-    }
-    setTimeout(() => fetchGasPrice({ gasPrices, oracleIndex }), 15000)
-  } catch (e) {
-    setTimeout(() => fetchGasPrice({ gasPrices, oracleIndex }), 15000)
-  }
-}
-
-async function fetchDAIprice({ ethPriceInDai, web3 }) {
-  try {
-    const ethDaiInstance = web3.eth.Contract(oracleABI, ethdaiAddress)
-    const price = await ethDaiInstance.methods.getMedianPrice().call()
-    ethPriceInDai = hexToNumberString(price)
-    setTimeout(() => fetchDAIprice({ ethPriceInDai, web3 }), 1000 * 30)
-  } catch(e) {
-    setTimeout(() => fetchDAIprice({ ethPriceInDai, web3 }), 1000 * 30)
-  }
-}
 
 function isValidProof(proof) {
   // validator expects `websnarkUtils.toSolidityInput(proof)` output
@@ -97,7 +56,7 @@ function sleep(ms) {
   return new Promise(resolve => setTimeout(resolve, ms))
 }
 
-function isEnoughFee({ gas, gasPrices, currency, refund, ethPriceInDai, fee }) {
+function isEnoughFee({ gas, gasPrices, currency, refund, ethPrices, fee }) {
   const expense = toBN(toWei(gasPrices.fast.toString(), 'gwei')).mul(toBN(gas))
   let desiredFee
   switch (currency) {
@@ -106,14 +65,15 @@ function isEnoughFee({ gas, gasPrices, currency, refund, ethPriceInDai, fee }) {
       break
     }
     case 'dai': {
-      desiredFee = expense.add(refund).mul(toBN(ethPriceInDai)).div(toBN(10 ** 18))
+      desiredFee = expense.add(refund).mul(toBN(ethPrices.dai)).div(toBN(10 ** 18))
       break
     }
   }
+  console.log('desired fee', desiredFee)
   if (fee.lt(desiredFee)) {
     return { isEnough: false, reason: 'Not enough fee' }
   } 
   return { isEnough: true }
 }
 
-module.exports = { fetchGasPrice, isValidProof, isValidArgs, sleep, fetchDAIprice, isKnownContract, isEnoughFee }
+module.exports = { isValidProof, isValidArgs, sleep, isKnownContract, isEnoughFee }