Merge pull request #2 from peppersec/erc20_support

Erc20 support
2024-10-01 08:25:37 -04:00 · 2019-12-04 11:20:03 -08:00 · 2019-12-04 11:20:03 -08:00 · c760a3e056
commit c760a3e056
parent b1244a87b4 8accbb2e6b
22 changed files with 5747 additions and 3977 deletions
--- a/.env.example
+++ b/.env.example
@ -1,4 +1,7 @@
 NET_ID=42
 RPC_URL=https://kovan.infura.io/v3/a3f4d001c1fc4a359ea70dd27fd9cb51
 PRIVATE_KEY=
-MIXER_ADDRESS=0xb2aD997a43768aB9279Cd9E72D5B75D789a09011
+# 2.5 means 2.5%
+RELAYER_FEE=2.5
+
+APP_PORT=8000
--- a/.eslintrc.json
+++ b/.eslintrc.json
@ -16,7 +16,8 @@
    "rules": {
        "indent": [
            "error",
-            2
+            2,
+            {"SwitchCase": 1}
        ],
        "linebreak-style": [
            "error",
--- a/5
+++ b/5
@ -2,10 +2,9 @@ FROM node:11
 WORKDIR /app

 COPY package.json package-lock.json ./
-RUN npm install
-
+RUN npm install && npm cache clean --force
 COPY . .

 EXPOSE 8000
-HEALTHCHECK CMD curl -f http://localhost:8000/
+HEALTHCHECK CMD curl -f http://localhost:8000/status
 CMD ["npm", "run", "start"]
--- a/README.md
+++ b/README.md
@ -1,40 +1,35 @@
 # Relayer for Tornado mixer [![Build Status](https://travis-ci.org/peppersec/tornado-mixer-relayer.svg?branch=master)](https://travis-ci.org/peppersec/tornado-mixer-relayer)
+
 ## Setup
 1. `npm i`
 2. `cp .env.example .env`
 3. Modify `.env` as needed
+4. If you want to change contracts' addresses go to [config.js](./config.js) file.
+
+## Deploy Kovan
+1. `cp .env.example deploy/kovan/.env`
+2. `cd deploy/kovan`
+2. Modify `.env` as needed
+3. `docker-compose -p kovan up -d`

 ## Run locally
 1. `npm run start`
-2. `curl -X POST -H 'content-type:application/json' --data '<PROOF>' http://127.0.0.1:8000/relay`
+2. `curl -X POST -H 'content-type:application/json' --data '<input data>' http://127.0.0.1:8000/relay`
 Relayer should return a transaction hash.

-## Proof example
+
+## Input data example
 ```json
 {
-   "pi_a":[
-      "0x0ed9b1afc791a551f5baa2f84786963b1463ca3f7c68eb0de3b267e6cb491f05",
-      "0x1335f2af3c71e442fd82f63f8f1c605ca2612b8d0fa22b4cbd1239cca839aa3d"
-   ],
-   "pi_b":[
-      [
-         "0x000189f7f1067a768d116cd86980eae6963dd9bc6c1f8204ceacf90a94f60d81",
-         "0x1abb4b71da0efa67cbc76a97ac360826b17a88f07bd89151258bf076474a4804"
-      ],
-      [
-         "0x0526b509ba2cda2b21b09401d70d23ea0225be4fdaa9097af842ff6783d1e0f4",
-         "0x15b11f9f5441adeea61534105902170a409b228e159fe7428abf6e863fc05273"
-      ]
-   ],
-   "pi_c":[
-      "0x2cd9a2305827f7da64aa1a3136c11ae1d3d7b3cb69832d8c04ab39d8b9393cda",
-      "0x2090cd3f9d09d66ca4e1e9bed2c72d5fa174b47599cb47e572324b1a98a3cb7a"
-   ],
-   "publicSignals":[
-      "0x1e8a85160889dfb5c03a8e2a6cca18b4c476c0b486003e9ed666a33e04114658",
-      "0x00bfb0befe19eac571ecaf7858e50d70273fbe2952cc8431f59399bb28665796",
-      "0x00000000000000000000000003ebd0748aa4d1457cf479cce56309641e0a98f5",
-      "0x0000000000000000000000000000000000000000000000000000000000000000"
-   ]
+    "proof": "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",
+    "args": [
+        "0x1579d41e5290ab5bcec9a7df16705e49b5c0b869095299196c19c5e14462c9e3",
+        "0x0cf7f49c5b35c48b9e1d43713e0b46a75977e3d10521e9ac1e4c3cd5e3da1c5d",
+        "0x03ebd0748aa4d1457cf479cce56309641e0a98f5",
+        "0xbd4369dc854c5d5b79fe25492e3a3cfcb5d02da5",
+        "0x000000000000000000000000000000000000000000000000058d15e176280000",
+        "0x0000000000000000000000000000000000000000000000000000000000000000"
+    ],
+    "contract": "0xA27E34Ad97F171846bAf21399c370c9CE6129e0D"
 }
 ```
--- a/abis/mixerABI.json
+++ b/abis/mixerABI.json
@ -0,0 +1,498 @@
+[
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "internalType": "address",
+        "name": "_newOperator",
+        "type": "address"
+      }
+    ],
+    "name": "changeOperator",
+    "outputs": [],
+    "payable": false,
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "name": "nullifierHashes",
+    "outputs": [
+      {
+        "internalType": "bool",
+        "name": "",
+        "type": "bool"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "internalType": "bytes",
+        "name": "_proof",
+        "type": "bytes"
+      },
+      {
+        "internalType": "bytes32",
+        "name": "_root",
+        "type": "bytes32"
+      },
+      {
+        "internalType": "bytes32",
+        "name": "_nullifierHash",
+        "type": "bytes32"
+      },
+      {
+        "internalType": "address payable",
+        "name": "_recipient",
+        "type": "address"
+      },
+      {
+        "internalType": "address payable",
+        "name": "_relayer",
+        "type": "address"
+      },
+      {
+        "internalType": "uint256",
+        "name": "_fee",
+        "type": "uint256"
+      },
+      {
+        "internalType": "uint256",
+        "name": "_refund",
+        "type": "uint256"
+      }
+    ],
+    "name": "withdraw",
+    "outputs": [],
+    "payable": true,
+    "stateMutability": "payable",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "verifier",
+    "outputs": [
+      {
+        "internalType": "contract IVerifier",
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "_left",
+        "type": "bytes32"
+      },
+      {
+        "internalType": "bytes32",
+        "name": "_right",
+        "type": "bytes32"
+      }
+    ],
+    "name": "hashLeftRight",
+    "outputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "pure",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "FIELD_SIZE",
+    "outputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "levels",
+    "outputs": [
+      {
+        "internalType": "uint32",
+        "name": "",
+        "type": "uint32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "operator",
+    "outputs": [
+      {
+        "internalType": "address",
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "_root",
+        "type": "bytes32"
+      }
+    ],
+    "name": "isKnownRoot",
+    "outputs": [
+      {
+        "internalType": "bool",
+        "name": "",
+        "type": "bool"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "name": "commitments",
+    "outputs": [
+      {
+        "internalType": "bool",
+        "name": "",
+        "type": "bool"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "denomination",
+    "outputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "currentRootIndex",
+    "outputs": [
+      {
+        "internalType": "uint32",
+        "name": "",
+        "type": "uint32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "internalType": "address",
+        "name": "_newVerifier",
+        "type": "address"
+      }
+    ],
+    "name": "updateVerifier",
+    "outputs": [],
+    "payable": false,
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "_commitment",
+        "type": "bytes32"
+      }
+    ],
+    "name": "deposit",
+    "outputs": [],
+    "payable": true,
+    "stateMutability": "payable",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "getLastRoot",
+    "outputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "name": "roots",
+    "outputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "ROOT_HISTORY_SIZE",
+    "outputs": [
+      {
+        "internalType": "uint32",
+        "name": "",
+        "type": "uint32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "bytes32",
+        "name": "_nullifierHash",
+        "type": "bytes32"
+      }
+    ],
+    "name": "isSpent",
+    "outputs": [
+      {
+        "internalType": "bool",
+        "name": "",
+        "type": "bool"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "name": "zeros",
+    "outputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "ZERO_VALUE",
+    "outputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "internalType": "uint256",
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "name": "filledSubtrees",
+    "outputs": [
+      {
+        "internalType": "bytes32",
+        "name": "",
+        "type": "bytes32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "nextIndex",
+    "outputs": [
+      {
+        "internalType": "uint32",
+        "name": "",
+        "type": "uint32"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "contract IVerifier",
+        "name": "_verifier",
+        "type": "address"
+      },
+      {
+        "internalType": "uint256",
+        "name": "_denomination",
+        "type": "uint256"
+      },
+      {
+        "internalType": "uint32",
+        "name": "_merkleTreeHeight",
+        "type": "uint32"
+      },
+      {
+        "internalType": "address",
+        "name": "_operator",
+        "type": "address"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "nonpayable",
+    "type": "constructor"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "internalType": "bytes32",
+        "name": "commitment",
+        "type": "bytes32"
+      },
+      {
+        "indexed": false,
+        "internalType": "uint32",
+        "name": "leafIndex",
+        "type": "uint32"
+      },
+      {
+        "indexed": false,
+        "internalType": "uint256",
+        "name": "timestamp",
+        "type": "uint256"
+      }
+    ],
+    "name": "Deposit",
+    "type": "event"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "address",
+        "name": "to",
+        "type": "address"
+      },
+      {
+        "indexed": false,
+        "internalType": "bytes32",
+        "name": "nullifierHash",
+        "type": "bytes32"
+      },
+      {
+        "indexed": true,
+        "internalType": "address",
+        "name": "relayer",
+        "type": "address"
+      },
+      {
+        "indexed": false,
+        "internalType": "uint256",
+        "name": "fee",
+        "type": "uint256"
+      }
+    ],
+    "name": "Withdrawal",
+    "type": "event"
+  }
+]
--- a/config.js
+++ b/config.js
@ -1,10 +1,56 @@
 require('dotenv').config()

 module.exports = {
-  netId: process.env.NET_ID || 42,
+  netId: Number(process.env.NET_ID) || 42,
  rpcUrl: process.env.RPC_URL || 'https://kovan.infura.io/v3/a3f4d001c1fc4a359ea70dd27fd9cb51',
  privateKey: process.env.PRIVATE_KEY,
-  mixerAddress: process.env.MIXER_ADDRESS,
+  nonce: 0,
+  mixers: {
+    netId1: {
+      dai: {
+        mixerAddress: {
+          '100': undefined,
+          '500': undefined,
+          '1000': undefined,
+          '5000': undefined
+        },
+        tokenAddress: '0x6b175474e89094c44da98b954eedeac495271d0f',
+        decimals: 18
+      },
+      eth: {
+        mixerAddress: {
+          '0.1': undefined,
+          '1': undefined,
+          '10': undefined,
+          '100': undefined
+        },
+        decimals: 18
+      }
+    },
+    netId42: {
+      dai: {
+        mixerAddress: {
+          '100': '0x5D4538D2b07cD8Eb7b93c33B327f3E01A42e68d8',
+          '500': undefined,
+          '1000': undefined,
+          '5000': undefined
+        },
+        tokenAddress: '0x8c158c7e57161dd4d3cb02bf1a3a97fcc78b75fd',
+        decimals: 18
+      },
+      eth: {
+        mixerAddress: {
+          '0.1': '0xB7F60Bf8b969CE4B95Bb50a671860D99478C81Ee',
+          '1': '0x27e94B8cfa33EA2b47E209Ba69804d44642B3545',
+          '10': undefined,
+          '100': undefined
+        },
+        decimals: 18
+      }
+    }
+  },
  defaultGasPrice: 2,
-  gasOracleUrls: ['https://www.etherchain.org/api/gasPriceOracle', 'https://gasprice.poa.network/']
+  gasOracleUrls: ['https://www.etherchain.org/api/gasPriceOracle', 'https://gasprice.poa.network/'],
+  port: process.env.APP_PORT,
+  relayerServiceFee: Number(process.env.RELAYER_FEE)
 }
--- a/deploy/kovan/docker-compose.yml
+++ b/deploy/kovan/docker-compose.yml
@ -0,0 +1,18 @@
+version: '2.2'
+
+services:
+  relayer:
+    build: ../../
+    restart: always
+    environment:
+      NODE_ENV: production
+      VIRTUAL_HOST: kovan.tornado.cash
+      LETSENCRYPT_HOST: kovan.tornado.cash
+    env_file: ./.env
+    healthcheck:
+      test: curl -sS http://127.0.0.1:8000 || exit 1
+
+networks:
+  default:
+    external:
+      name: frontend_default
--- a/deploy/mainnet/docker-compose.yml
+++ b/deploy/mainnet/docker-compose.yml
@ -0,0 +1,18 @@
+version: '2.2'
+
+services:
+  relayer:
+    build: ../../
+    restart: always
+    environment:
+      NODE_ENV: production
+      VIRTUAL_HOST: mainnet.tornado.cash
+      LETSENCRYPT_HOST: mainnet.tornado.cash
+    env_file: ./.env
+    healthcheck:
+      test: curl -sS http://127.0.0.1:8000 || exit 1
+
+networks:
+  default:
+    external:
+      name: frontend_default
--- a/docker-compose.yml
+++ b/docker-compose.yml
@ -1,23 +0,0 @@
-version: '2'
-
-services:
-  relayer:
-    build: ./
-    restart: always
-    environment:
-      NODE_ENV: production
-      VIRTUAL_HOST: relayer.tornado.cash
-      LETSENCRYPT_HOST: relayer.tornado.cash
-    env_file: ./.env
-
-  monitor:
-    image: arefaslani/docker-telegram-notifier
-    restart: always
-    volumes:
-     - /var/run/docker.sock:/var/run/docker.sock
-    env_file: ./.env
-
-networks:
-  default:
-    external:
-      name: frontend_default
--- a/frontend/docker-compose.yml
+++ b/frontend/docker-compose.yml
@ -1,23 +0,0 @@
-version: '2'
-
-services:
-
-  nginx:
-    image: jwilder/nginx-proxy
-    restart: always
-    ports:
-      - 80:80
-      - 443:443
-    volumes:
-      - /var/run/docker.sock:/tmp/docker.sock:ro
-      - /etc/nginx/certs
-      - /etc/nginx/vhost.d
-      - /usr/share/nginx/html
-
-  letsencrypt:
-    image: jrcs/letsencrypt-nginx-proxy-companion
-    restart: always
-    volumes_from:
-      - nginx
-    volumes:
-      - /var/run/docker.sock:/var/run/docker.sock:ro
--- a/index.js
+++ b/index.js
@ -1,90 +0,0 @@
-const { numberToHex, toWei, toHex, toBN } = require('web3-utils')
-const Web3 = require('web3')
-const express = require('express')
-
-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()
-})
-
-const { netId, rpcUrl, privateKey, mixerAddress, defaultGasPrice } = require('./config')
-const { fetchGasPrice, isValidProof } = require('./utils')
-
-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('./mixerABI.json') 
-const mixer = new web3.eth.Contract(mixerABI, mixerAddress)
-const gasPrices = { fast: defaultGasPrice }
-
-app.get('/', function (req, res) {
-  // just for testing purposes
-  res.send(`Tornado mixer relayer. Gas Price is ${JSON.stringify(gasPrices)}. Mixer address is ${mixerAddress}`)
-})
-
-app.post('/relay', async (req, resp) => {
-  const { valid , reason } = isValidProof(req.body)
-  if (!valid) {
-    console.log('Proof is invalid:', reason)
-    return resp.status(400).json({ error: 'Proof is invalid' })
-  }
-
-  let { pi_a, pi_b, pi_c, publicSignals } = req.body
-
-  const fee = toBN(publicSignals[3])
-  const desiredFee = toBN(toWei(gasPrices.fast.toString(), 'gwei')).mul(toBN('1000000'))
-  if (fee.lt(desiredFee)) {
-    console.log('Fee is too low')
-    return resp.status(400).json({ error: 'Fee is too low. Try to resend.' })
-  }
-
-  try {
-    const nullifier = publicSignals[1]
-    const isSpent = await mixer.methods.isSpent(nullifier).call()
-    if (isSpent) {
-      return resp.status(400).json({ error: 'The note has been spent.' })
-    }
-    const root = publicSignals[0]
-    const isKnownRoot = await mixer.methods.isKnownRoot(root).call()
-    if (!isKnownRoot) {
-      return resp.status(400).json({ error: 'The merkle root is too old or invalid.' })
-    }
-    const gas = await mixer.methods.withdraw(pi_a, pi_b, pi_c, publicSignals).estimateGas()
-    const result = mixer.methods.withdraw(pi_a, pi_b, pi_c, publicSignals).send({
-      gas: numberToHex(gas + 50000),
-      gasPrice: toHex(toWei(gasPrices.fast.toString(), 'gwei')),
-      // TODO: nonce
-    })
-    result.once('transactionHash', function(hash){
-      resp.json({ txHash: hash })
-    }).on('error', function(e){
-      console.log(e)
-      return resp.status(400).json({ error: 'Proof is malformed.' })
-    })
-  } catch (e) {
-    console.log(e)
-    return resp.status(400).json({ error: 'Proof is malformed or spent.' })
-  }
-})
-
-app.listen(8000)
-
-if (Number(netId) === 1) {
-  fetchGasPrice({ gasPrices })
-  console.log('Gas price oracle started.')
-}
--- a/mixerABI.json
+++ b/mixerABI.json
@ -1,320 +0,0 @@
-[
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "filled_subtrees",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256[]"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "name": "nullifierHashes",
-    "outputs": [
-      {
-        "name": "",
-        "type": "bool"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "transferValue",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "roots",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256[]"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "name": "commitments",
-    "outputs": [
-      {
-        "name": "",
-        "type": "bool"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "zeros",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256[]"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "levels",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [
-      {
-        "name": "left",
-        "type": "uint256"
-      },
-      {
-        "name": "right",
-        "type": "uint256"
-      }
-    ],
-    "name": "hashLeftRight",
-    "outputs": [
-      {
-        "name": "mimc_hash",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "pure",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "next_index",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint32"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "current_root",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [
-      {
-        "name": "root",
-        "type": "uint256"
-      }
-    ],
-    "name": "isKnownRoot",
-    "outputs": [
-      {
-        "name": "",
-        "type": "bool"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [],
-    "name": "getLastRoot",
-    "outputs": [
-      {
-        "name": "",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  },
-  {
-    "inputs": [
-      {
-        "name": "_verifier",
-        "type": "address"
-      },
-      {
-        "name": "_transferValue",
-        "type": "uint256"
-      },
-      {
-        "name": "_merkleTreeHeight",
-        "type": "uint8"
-      },
-      {
-        "name": "_emptyElement",
-        "type": "uint256"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "nonpayable",
-    "type": "constructor"
-  },
-  {
-    "anonymous": false,
-    "inputs": [
-      {
-        "indexed": true,
-        "name": "commitment",
-        "type": "uint256"
-      },
-      {
-        "indexed": false,
-        "name": "leafIndex",
-        "type": "uint256"
-      },
-      {
-        "indexed": false,
-        "name": "timestamp",
-        "type": "uint256"
-      }
-    ],
-    "name": "Deposit",
-    "type": "event"
-  },
-  {
-    "anonymous": false,
-    "inputs": [
-      {
-        "indexed": false,
-        "name": "to",
-        "type": "address"
-      },
-      {
-        "indexed": false,
-        "name": "nullifierHash",
-        "type": "uint256"
-      },
-      {
-        "indexed": false,
-        "name": "fee",
-        "type": "uint256"
-      }
-    ],
-    "name": "Withdraw",
-    "type": "event"
-  },
-  {
-    "constant": false,
-    "inputs": [
-      {
-        "name": "commitment",
-        "type": "uint256"
-      }
-    ],
-    "name": "deposit",
-    "outputs": [],
-    "payable": true,
-    "stateMutability": "payable",
-    "type": "function"
-  },
-  {
-    "constant": false,
-    "inputs": [
-      {
-        "name": "a",
-        "type": "uint256[2]"
-      },
-      {
-        "name": "b",
-        "type": "uint256[2][2]"
-      },
-      {
-        "name": "c",
-        "type": "uint256[2]"
-      },
-      {
-        "name": "input",
-        "type": "uint256[4]"
-      }
-    ],
-    "name": "withdraw",
-    "outputs": [],
-    "payable": false,
-    "stateMutability": "nonpayable",
-    "type": "function"
-  },
-  {
-    "constant": true,
-    "inputs": [
-      {
-        "name": "nullifier",
-        "type": "uint256"
-      }
-    ],
-    "name": "isSpent",
-    "outputs": [
-      {
-        "name": "",
-        "type": "bool"
-      }
-    ],
-    "payable": false,
-    "stateMutability": "view",
-    "type": "function"
-  }
-]
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@ -2,22 +2,23 @@
  "name": "relay",
  "version": "1.0.0",
  "description": "Relayer for Tornado mixer. https://tornado.cash",
-  "main": "index.js",
+  "main": "src/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": {
-    "dotenv": "^8.0.0",
+    "coingecko-api": "^1.0.6",
+    "dotenv": "^8.2.0",
    "express": "^4.17.1",
    "node-fetch": "^2.6.0",
-    "web3": "^1.0.0-beta.55",
-    "web3-utils": "^1.0.0"
+    "web3": "^1.2.2",
+    "web3-utils": "^1.2.2"
  },
  "devDependencies": {
-    "eslint": "^6.0.1"
+    "eslint": "^6.6.0"
  }
 }
--- a/src/Fetcher.js
+++ b/src/Fetcher.js
@ -0,0 +1,77 @@
+const CoinGecko = require('coingecko-api') 
+const fetch = require('node-fetch')
+const { toWei } = require('web3-utils')
+const { gasOracleUrls, defaultGasPrice } = require('../config')
+const { getMainnetTokens } = require('./utils')
+const config = require ('../config')
+ 
+
+class Fetcher {
+  constructor(web3) {
+    this.web3 = web3
+    this.ethPrices = {
+      dai: '6700000000000000' // 0.0067
+    }
+    this.gasPrices = {
+      fast: defaultGasPrice
+    }
+  }
+  async fetchPrices() {
+    const { tokenAddresses, currencyLookup } = getMainnetTokens()
+    try {
+      const CoinGeckoClient = new CoinGecko()
+      const price = await CoinGeckoClient.simple.fetchTokenPrice({
+        contract_addresses: tokenAddresses,
+        vs_currencies: 'eth',
+        assetPlatform: 'ethereum'
+      })
+      this.ethPrices = Object.entries(price.data).reduce((acc, token) => {
+        if (token[1].eth) {
+          acc[currencyLookup[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)
+    }
+  }
+  async fetchNonce() {
+    try {
+      config.nonce = await this.web3.eth.getTransactionCount(this.web3.eth.defaultAccount)
+      console.log(`Current nonce: ${config.nonce}`)
+    } catch(e) {
+      console.error('fetchNonce failed', e.message)
+      setTimeout(this.fetchNonce, 3000)
+    }
+  }
+}
+
+module.exports = Fetcher
--- a/src/index.js
+++ b/src/index.js
@ -0,0 +1,50 @@
+const express = require('express')
+const { netId, port, relayerServiceFee } = require('../config')
+const relayController = require('./relayController')
+const { fetcher, web3 } = require('./instances')
+const { getMixers } = require('./utils')
+const mixers = getMixers()
+
+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, relayerServiceFee })
+})
+
+app.post('/relay', relayController)
+
+app.listen(port || 8000)
+console.log('Gas price oracle started.')
+fetcher.fetchGasPrice()
+fetcher.fetchPrices()
+fetcher.fetchNonce()
+
+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)}`)
+console.log(`Service fee: ${relayerServiceFee}%`)
--- a/src/instances.js
+++ b/src/instances.js
@ -0,0 +1,8 @@
+const Fetcher = require('./Fetcher')
+const web3 = require('./setupWeb3')
+const fetcher = new Fetcher(web3)
+
+module.exports = {
+  fetcher,
+  web3
+}
--- a/src/relayController.js
+++ b/src/relayController.js
@ -0,0 +1,103 @@
+const { numberToHex, toWei, toHex, toBN, toChecksumAddress } = require('web3-utils')
+const mixerABI = require('../abis/mixerABI.json')
+const { 
+  isValidProof, isValidArgs, isKnownContract, isEnoughFee
+} = require('./utils')
+const config = require('../config')
+
+const { web3, fetcher } = require('./instances')
+
+async function relay (req, resp) {
+  const { proof, args, contract } = req.body
+  const gasPrices = fetcher.gasPrices
+  let { valid , reason } = isValidProof(proof)
+  if (!valid) {
+    console.log('Proof is invalid:', reason)
+    return resp.status(400).json({ error: 'Proof format is invalid' })
+  }
+
+  ({ valid , reason } = isValidArgs(args))
+  if (!valid) {
+    console.log('Args are invalid:', reason)
+    return resp.status(400).json({ error: 'Withdraw arguments are invalid' })
+  }
+
+  let currency, amount
+  ( { valid, currency, amount } = isKnownContract(contract))
+  if (!valid) {
+    console.log('Contract does not exist:', contract)
+    return resp.status(400).json({ error: 'This relayer does not support the token' })
+  }
+
+  const [ root, nullifierHash, recipient, relayer, fee, refund ] = [
+    args[0],
+    args[1],
+    toChecksumAddress(args[2]),
+    toChecksumAddress(args[3]),
+    toBN(args[4]),
+    toBN(args[5])
+  ]
+  console.log('fee, refund', fee.toString(), refund.toString())
+  if (currency === 'eth' && !refund.isZero()) {
+    return resp.status(400).json({ error: 'Cannot send refund for eth currency.' })
+  }
+
+  if (relayer !== web3.eth.defaultAccount) {
+    console.log('This proof is for different relayer:', relayer)
+    return resp.status(400).json({ error: 'Relayer address is invalid' })
+  }
+
+  try {
+    const mixer = new web3.eth.Contract(mixerABI, req.body.contract)
+    const isSpent = await mixer.methods.isSpent(nullifierHash).call()
+    if (isSpent) {
+      return resp.status(400).json({ error: 'The note has been spent.' })
+    }
+    const isKnownRoot = await mixer.methods.isKnownRoot(root).call()
+    if (!isKnownRoot) {
+      return resp.status(400).json({ error: 'The merkle root is too old or invalid.' })
+    }
+
+    let gas = await mixer.methods.withdraw(proof, ...args).estimateGas({
+      from: web3.eth.defaultAccount,
+      value: refund 
+    })
+
+    gas += 50000
+    const ethPrices = fetcher.ethPrices
+    const { isEnough, reason } = isEnoughFee({ gas, gasPrices, currency, amount, refund, ethPrices, fee })
+    if (!isEnough) {
+      console.log(`Wrong fee: ${reason}`)
+      return resp.status(400).json({ error: reason })
+    }
+
+    const data = mixer.methods.withdraw(proof, ...args).encodeABI()
+    const tx = {
+      from: web3.eth.defaultAccount,
+      value: numberToHex(refund),
+      gas: numberToHex(gas),
+      gasPrice: toHex(toWei(gasPrices.fast.toString(), 'gwei')),
+      to: mixer._address,
+      netId: config.netId,
+      data,
+      nonce: config.nonce
+    }
+    config.nonce++
+    let signedTx = await web3.eth.accounts.signTransaction(tx, config.privateKey)
+    let result = web3.eth.sendSignedTransaction(signedTx.rawTransaction)
+
+    result.once('transactionHash', function(txHash){
+      resp.json({ txHash })
+      console.log(`A new successfully sent tx ${txHash} for the ${recipient}`)
+    }).on('error', function(e){
+      config.nonce--
+      console.error('on transactionHash error', e.message)
+      return resp.status(400).json({ error: 'Proof is malformed.' })
+    })
+  } catch (e) {
+    console.error(e, 'estimate gas failed')
+    return resp.status(400).json({ error: 'Proof is malformed or spent.' })
+  }
+}
+
+module.exports = relay
--- a/src/setupWeb3.js
+++ b/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
--- a/src/utils.js
+++ b/src/utils.js
@ -0,0 +1,105 @@
+const { isHexStrict, toBN, toWei } = require('web3-utils')
+const { netId, mixers, relayerServiceFee } = require('../config')
+
+function isValidProof(proof) {
+  // validator expects `websnarkUtils.toSolidityInput(proof)` output
+
+  if (!(proof)) {
+    return { valid: false, reason: 'The proof is empty.' }
+  }
+
+  if (!isHexStrict(proof) || proof.length !== 2 + 2 * 8 * 32) {
+    return { valid: false, reason: 'Corrupted proof' }
+  }
+
+  return { valid: true }
+}
+
+function isValidArgs(args) {
+
+  if (!(args)) {
+    return { valid: false, reason: 'Args are empty' }
+  }
+
+  if (args.length !== 6) {
+    return { valid: false, reason: 'Length of args is lower than 6' }
+  }
+
+  for(let signal of args) {
+    if (!isHexStrict(signal)) {
+      return { valid: false, reason: `Corrupted signal ${signal}` }
+    }
+  }
+
+  if (args[0].length !== 66 ||
+      args[1].length !== 66 ||
+      args[2].length !== 42 ||
+      args[3].length !== 42 ||
+      args[4].length !== 66 ||
+      args[5].length !== 66) {
+    return { valid: false, reason: 'The length one of the signals is incorrect' }
+  }
+
+  return { valid: true }
+}
+
+function isKnownContract(contract) {
+  const mixers = getMixers()
+  for (let currency of Object.keys(mixers)) {
+    for (let amount of Object.keys(mixers[currency].mixerAddress)) {
+      if (mixers[currency].mixerAddress[amount] === contract) {
+        return { valid: true, currency, amount }
+      }
+    }
+  }
+  return { valid: false }
+}
+
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}
+
+function isEnoughFee({ gas, gasPrices, currency, amount, refund, ethPrices, fee }) {
+  // TODO tokens can have less then 18 decimals
+  const feePercent = toBN(toWei(amount)).mul(toBN(relayerServiceFee * 10)).div(toBN('1000'))
+  const expense = toBN(toWei(gasPrices.fast.toString(), 'gwei')).mul(toBN(gas))
+  let desiredFee
+  switch (currency) {
+    case 'eth': {
+      desiredFee = expense.add(feePercent)
+      break
+    }
+    case 'dai': {
+      desiredFee = 
+        expense.add(refund)
+          .mul(toBN(10 ** 18))
+          .div(toBN(ethPrices.dai))
+      desiredFee = desiredFee.add(feePercent)
+      break
+    }
+  }
+  console.log('desired fee, feePercent', desiredFee.toString(), feePercent.toString())
+  if (fee.lt(desiredFee)) {
+    return { isEnough: false, reason: 'Not enough fee' }
+  } 
+  return { isEnough: true }
+}
+
+function getMainnetTokens() {
+  const tokens = mixers['netId1']
+  const tokenAddresses = []
+  const currencyLookup = {}
+  Object.entries(tokens).map(([currency, data]) => {
+    if (currency !== 'eth') {
+      tokenAddresses.push(data.tokenAddress)
+      currencyLookup[data.tokenAddress] = currency
+    }
+  })
+  return { tokenAddresses, currencyLookup }
+}
+
+function getMixers() {
+  return mixers[`netId${netId}`]
+}
+
+module.exports = { isValidProof, isValidArgs, sleep, isKnownContract, isEnoughFee, getMixers, getMainnetTokens }
--- a/utils.js
+++ b/utils.js
@ -1,85 +0,0 @@
-const fetch = require('node-fetch')
-const { isHexStrict } = require('web3-utils')
-const { gasOracleUrls } = require('./config')
-
-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)
-  }
-}
-
-function isValidProof(proof) {
-  // validator expects `websnarkUtils.toSolidityInput(proof)` output
-
-  if (!(proof.pi_a && proof.pi_b && proof.pi_c && proof.publicSignals)) {
-    return { valid: false, reason: 'One of inputs is empty. There must be pi_a, pi_b, pi_c and publicSignals' }
-  }
-
-  Object.keys(proof).forEach(key => {
-    if (!Array.isArray(proof[key])) {
-      return { valid: false, reason: `Corrupted ${key}` }
-    }
-    if (key === 'pi_b') {
-      if (!Array.isArray(proof[key][0]) || !Array.isArray(proof[key][1])) {
-        return { valid: false, reason: `Corrupted ${key}` }
-      }
-    }
-  })
-
-  if (proof.pi_a.length !== 2) {
-    return { valid: false, reason: 'Corrupted pi_a' }
-  }
-
-  if (proof.pi_b.length !== 2 || proof.pi_b[0].length !== 2 || proof.pi_b[1].length !== 2) {
-    return { valid: false, reason: 'Corrupted pi_b' }
-  }
-
-  if (proof.pi_c.length !== 2) {
-    return { valid: false, reason: 'Corrupted pi_c' }
-  }
-
-  if (proof.publicSignals.length !== 4) {
-    return { valid: false, reason: 'Corrupted publicSignals' }
-  }
-
-  for (let [key, input] of Object.entries(proof)) {
-    if (key === 'pi_b') {
-      input = input[0].concat(input[1])
-    }
-
-    for (let i = 0; i < input.length; i++ ) {
-      if (!isHexStrict(input[i]) || input[i].length !== 66) {
-        return { valid: false, reason: `Corrupted ${key}` }
-      }
-    }
-  }
-  return { valid: true }
-}
-
-function sleep(ms) {
-  return new Promise(resolve => setTimeout(resolve, ms))
-}
-
-module.exports = { fetchGasPrice, isValidProof, sleep }
--- a/yarn.lock
+++ b/yarn.lock