tornado-core/cli.js
2020-02-27 16:32:10 +03:00

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#!/usr/bin/env NODE_OPTIONS=--no-warnings node
// Temporary demo client
// Works both in browser and node.js
require('dotenv').config()
const fs = require('fs')
const axios = require('axios')
const assert = require('assert')
const snarkjs = require('snarkjs')
const crypto = require('crypto')
const circomlib = require('circomlib')
const bigInt = snarkjs.bigInt
const merkleTree = require('./lib/MerkleTree')
const Web3 = require('web3')
const buildGroth16 = require('websnark/src/groth16')
const websnarkUtils = require('websnark/src/utils')
const { toWei, fromWei, toBN, BN } = require('web3-utils')
const config = require('./config')
const program = require('commander')
let web3, tornado, circuit, proving_key, groth16, erc20, senderAccount, netId
let MERKLE_TREE_HEIGHT, ETH_AMOUNT, TOKEN_AMOUNT, PRIVATE_KEY
/** Whether we are in a browser or node.js */
const inBrowser = (typeof window !== 'undefined')
let isLocalRPC = false
const networks = { '1': 'mainnet', '42': 'kovan' }
/** Generate random number of specified byte length */
const rbigint = nbytes => snarkjs.bigInt.leBuff2int(crypto.randomBytes(nbytes))
/** Compute pedersen hash */
const pedersenHash = data => circomlib.babyJub.unpackPoint(circomlib.pedersenHash.hash(data))[0]
/** BigNumber to hex string of specified length */
function toHex(number, length = 32) {
const str = number instanceof Buffer ? number.toString('hex') : bigInt(number).toString(16)
return '0x' + str.padStart(length * 2, '0')
}
/** Display ETH account balance */
async function printETHBalance({ address, name }) {
console.log(`${name} ETH balance is`, web3.utils.fromWei(await web3.eth.getBalance(address)))
}
/** Display ERC20 account balance */
async function printERC20Balance({ address, name, tokenAddress }) {
const erc20ContractJson = require('./build/contracts/ERC20Mock.json')
erc20 = tokenAddress ? new web3.eth.Contract(erc20ContractJson.abi, tokenAddress) : erc20
console.log(`${name} Token Balance is`, web3.utils.fromWei(await erc20.methods.balanceOf(address).call()))
}
/**
* Create deposit object from secret and nullifier
*/
function createDeposit({ nullifier, secret }) {
const deposit = { nullifier, secret }
deposit.preimage = Buffer.concat([deposit.nullifier.leInt2Buff(31), deposit.secret.leInt2Buff(31)])
deposit.commitment = pedersenHash(deposit.preimage)
deposit.nullifierHash = pedersenHash(deposit.nullifier.leInt2Buff(31))
return deposit
}
/**
* Make a deposit
* @param currency Сurrency
* @param amount Deposit amount
*/
async function deposit({ currency, amount }) {
const deposit = createDeposit({ nullifier: rbigint(31), secret: rbigint(31) })
const note = toHex(deposit.preimage, 62)
const noteString = `tornado-${currency}-${amount}-${netId}-${note}`
console.log(`Your note: ${noteString}`)
if (currency === 'eth') {
await printETHBalance({ address: tornado._address, name: 'Tornado' })
await printETHBalance({ address: senderAccount, name: 'Sender account' })
const value = isLocalRPC ? ETH_AMOUNT : fromDecimals({ amount, decimals: 18 })
console.log('Submitting deposit transaction')
await tornado.methods.deposit(toHex(deposit.commitment)).send({ value, from: senderAccount, gas:2e6 })
await printETHBalance({ address: tornado._address, name: 'Tornado' })
await printETHBalance({ address: senderAccount, name: 'Sender account' })
} else { // a token
await printERC20Balance({ address: tornado._address, name: 'Tornado' })
await printERC20Balance({ address: senderAccount, name: 'Sender account' })
const decimals = isLocalRPC ? 18 : config.deployments[`netId${netId}`][currency].decimals
const tokenAmount = isLocalRPC ? TOKEN_AMOUNT : fromDecimals({ amount, decimals })
if(isLocalRPC) {
console.log('Minting some test tokens to deposit')
await erc20.methods.mint(senderAccount, tokenAmount).send({ from: senderAccount, gas: 2e6 })
}
const allowance = await erc20.methods.allowance(senderAccount, tornado._address).call({ from: senderAccount })
console.log('Current allowance is', fromWei(allowance))
if (toBN(allowance).lt(toBN(tokenAmount))) {
console.log('Approving tokens for deposit')
await erc20.methods.approve(tornado._address, tokenAmount).send({ from: senderAccount, gas:1e6 })
}
console.log('Submitting deposit transaction')
await tornado.methods.deposit(toHex(deposit.commitment)).send({ from: senderAccount, gas:2e6 })
await printERC20Balance({ address: tornado._address, name: 'Tornado' })
await printERC20Balance({ address: senderAccount, name: 'Sender account' })
}
return noteString
}
/**
* Generate merkle tree for a deposit.
* Download deposit events from the tornado, reconstructs merkle tree, finds our deposit leaf
* in it and generates merkle proof
* @param deposit Deposit object
*/
async function generateMerkleProof(deposit) {
// Get all deposit events from smart contract and assemble merkle tree from them
console.log('Getting current state from tornado contract')
const events = await tornado.getPastEvents('Deposit', { fromBlock: 0, toBlock: 'latest' })
const leaves = events
.sort((a, b) => a.returnValues.leafIndex - b.returnValues.leafIndex) // Sort events in chronological order
.map(e => e.returnValues.commitment)
const tree = new merkleTree(MERKLE_TREE_HEIGHT, leaves)
// Find current commitment in the tree
const depositEvent = events.find(e => e.returnValues.commitment === toHex(deposit.commitment))
const leafIndex = depositEvent ? depositEvent.returnValues.leafIndex : -1
// Validate that our data is correct
const isValidRoot = await tornado.methods.isKnownRoot(toHex(await tree.root())).call()
const isSpent = await tornado.methods.isSpent(toHex(deposit.nullifierHash)).call()
assert(isValidRoot === true, 'Merkle tree is corrupted')
assert(isSpent === false, 'The note is already spent')
assert(leafIndex >= 0, 'The deposit is not found in the tree')
// Compute merkle proof of our commitment
return tree.path(leafIndex)
}
/**
* Generate SNARK proof for withdrawal
* @param deposit Deposit object
* @param recipient Funds recipient
* @param relayer Relayer address
* @param fee Relayer fee
* @param refund Receive ether for exchanged tokens
*/
async function generateProof({ deposit, recipient, relayerAddress = 0, fee = 0, refund = 0 }) {
// Compute merkle proof of our commitment
const { root, path_elements, path_index } = await generateMerkleProof(deposit)
// Prepare circuit input
const input = {
// Public snark inputs
root: root,
nullifierHash: deposit.nullifierHash,
recipient: bigInt(recipient),
relayer: bigInt(relayerAddress),
fee: bigInt(fee),
refund: bigInt(refund),
// Private snark inputs
nullifier: deposit.nullifier,
secret: deposit.secret,
pathElements: path_elements,
pathIndices: path_index,
}
console.log('Generating SNARK proof')
console.time('Proof time')
const proofData = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
const { proof } = websnarkUtils.toSolidityInput(proofData)
console.timeEnd('Proof time')
const args = [
toHex(input.root),
toHex(input.nullifierHash),
toHex(input.recipient, 20),
toHex(input.relayer, 20),
toHex(input.fee),
toHex(input.refund)
]
return { proof, args }
}
/**
* Do an ETH withdrawal
* @param noteString Note to withdraw
* @param recipient Recipient address
*/
async function withdraw({ deposit, currency, amount, recipient, relayerURL, refund = '0' }) {
if (currency === 'eth' && refund !== '0') {
throw new Error('The ETH purchase is supposted to be 0 for ETH withdrawals')
}
refund = toWei(refund)
if (relayerURL) {
const relayerStatus = await axios.get(relayerURL + '/status')
const { relayerAddress, netId, gasPrices, ethPrices, relayerServiceFee } = relayerStatus.data
assert(netId === await web3.eth.net.getId() || netId === '*', 'This relay is for different network')
console.log('Relay address: ', relayerAddress)
const decimals = isLocalRPC ? 18 : config.deployments[`netId${netId}`][currency].decimals
const fee = calculateFee({ gasPrices, currency, amount, refund, ethPrices, relayerServiceFee, decimals })
if (fee.gt(fromDecimals({ amount, decimals }))) {
throw new Error('Too high refund')
}
const { proof, args } = await generateProof({ deposit, recipient, relayerAddress, fee, refund })
console.log('Sending withdraw transaction through relay')
try{
const relay = await axios.post(relayerURL + '/relay', { contract: tornado._address, proof, args })
if (netId === 1 || netId === 42) {
console.log(`Transaction submitted through the relay. View transaction on etherscan https://${networks[netId]}.etherscan.io/tx/${relay.data.txHash}`)
} else {
console.log(`Transaction submitted through the relay. The transaction hash is ${relay.data.txHash}`)
}
const receipt = await waitForTxReceipt({ txHash: relay.data.txHash })
console.log('Transaction mined in block', receipt.blockNumber)
} catch(e) {
if (e.response) {
console.error(e.response.data.error)
} else {
console.error(e.message)
}
}
} else { // using private key
const { proof, args } = await generateProof({ deposit, recipient, refund })
console.log('Submitting withdraw transaction')
await tornado.methods.withdraw(proof, ...args).send({ from: senderAccount, value: refund.toString(), gas: 1e6 })
.on('transactionHash', function(txHash){
if (netId === 1 || netId === 42) {
console.log(`View transaction on etherscan https://${networks[netId]}.etherscan.io/tx/${txHash}`)
} else {
console.log(`The transaction hash is ${txHash}`)
}
}).on('error', function(e){
console.error('on transactionHash error', e.message)
})
}
console.log('Done')
}
function fromDecimals({ amount, decimals }) {
amount = amount.toString()
let ether = amount.toString()
const base = new BN('10').pow(new BN(decimals))
const baseLength = base.toString(10).length - 1 || 1
const negative = ether.substring(0, 1) === '-'
if (negative) {
ether = ether.substring(1)
}
if (ether === '.') {
throw new Error('[ethjs-unit] while converting number ' + amount + ' to wei, invalid value')
}
// Split it into a whole and fractional part
const comps = ether.split('.')
if (comps.length > 2) {
throw new Error(
'[ethjs-unit] while converting number ' + amount + ' to wei, too many decimal points'
)
}
let whole = comps[0]
let fraction = comps[1]
if (!whole) {
whole = '0'
}
if (!fraction) {
fraction = '0'
}
if (fraction.length > baseLength) {
throw new Error(
'[ethjs-unit] while converting number ' + amount + ' to wei, too many decimal places'
)
}
while (fraction.length < baseLength) {
fraction += '0'
}
whole = new BN(whole)
fraction = new BN(fraction)
let wei = whole.mul(base).add(fraction)
if (negative) {
wei = wei.mul(negative)
}
return new BN(wei.toString(10), 10)
}
function calculateFee({ gasPrices, currency, amount, refund, ethPrices, relayerServiceFee, decimals }) {
const feePercent = toBN(fromDecimals({ amount, decimals })).mul(toBN(relayerServiceFee * 10)).div(toBN('1000'))
const expense = toBN(toWei(gasPrices.fast.toString(), 'gwei')).mul(toBN(5e5))
let desiredFee
switch (currency) {
case 'eth': {
desiredFee = expense.add(feePercent)
break
}
default: {
desiredFee =
expense.add(toBN(refund))
.mul(toBN(10 ** decimals))
.div(toBN(ethPrices[currency]))
desiredFee = desiredFee.add(feePercent)
break
}
}
return desiredFee
}
/**
* Waits for transaction to be mined
* @param txHash Hash of transaction
* @param attempts
* @param delay
*/
function waitForTxReceipt({ txHash, attempts = 60, delay = 1000 }) {
return new Promise((resolve, reject) => {
const checkForTx = async (txHash, retryAttempt = 0) => {
const result = await web3.eth.getTransactionReceipt(txHash)
if (!result || !result.blockNumber) {
if (retryAttempt <= attempts) {
setTimeout(() => checkForTx(txHash, retryAttempt + 1), delay)
} else {
reject(new Error('tx was not mined'))
}
} else {
resolve(result)
}
}
checkForTx(txHash)
})
}
/**
* Parses Tornado.cash note
* @param noteString the note
*/
function parseNote(noteString) {
const noteRegex = /tornado-(?<currency>\w+)-(?<amount>[\d.]+)-(?<netId>\d+)-0x(?<note>[0-9a-fA-F]{124})/g
const match = noteRegex.exec(noteString)
if (!match) {
throw new Error('The note has invalid format')
}
const buf = Buffer.from(match.groups.note, 'hex')
const nullifier = bigInt.leBuff2int(buf.slice(0, 31))
const secret = bigInt.leBuff2int(buf.slice(31, 62))
const deposit = createDeposit({ nullifier, secret })
const netId = Number(match.groups.netId)
return { currency: match.groups.currency, amount: match.groups.amount, netId, deposit }
}
/**
* Init web3, contracts, and snark
*/
async function init({ rpc, noteNetId, currency = 'dai', amount = '100' }) {
let contractJson, erc20ContractJson, erc20tornadoJson, tornadoAddress, tokenAddress
// TODO do we need this? should it work in browser really?
if (inBrowser) {
// Initialize using injected web3 (Metamask)
// To assemble web version run `npm run browserify`
web3 = new Web3(window.web3.currentProvider, null, { transactionConfirmationBlocks: 1 })
contractJson = await (await fetch('build/contracts/ETHTornado.json')).json()
circuit = await (await fetch('build/circuits/withdraw.json')).json()
proving_key = await (await fetch('build/circuits/withdraw_proving_key.bin')).arrayBuffer()
MERKLE_TREE_HEIGHT = 20
ETH_AMOUNT = 1e18
TOKEN_AMOUNT = 1e19
senderAccount = (await web3.eth.getAccounts())[0]
} else {
// Initialize from local node
web3 = new Web3(rpc, null, { transactionConfirmationBlocks: 1 })
contractJson = require('./build/contracts/ETHTornado.json')
circuit = require('./build/circuits/withdraw.json')
proving_key = fs.readFileSync('build/circuits/withdraw_proving_key.bin').buffer
MERKLE_TREE_HEIGHT = process.env.MERKLE_TREE_HEIGHT
ETH_AMOUNT = process.env.ETH_AMOUNT
TOKEN_AMOUNT = process.env.TOKEN_AMOUNT
PRIVATE_KEY = process.env.PRIVATE_KEY
erc20ContractJson = require('./build/contracts/ERC20Mock.json')
erc20tornadoJson = require('./build/contracts/ERC20Tornado.json')
const account = web3.eth.accounts.privateKeyToAccount('0x' + PRIVATE_KEY)
web3.eth.accounts.wallet.add('0x' + PRIVATE_KEY)
web3.eth.defaultAccount = account.address
senderAccount = account.address
}
// groth16 initialises a lot of Promises that will never be resolved, that's why we need to use process.exit to terminate the CLI
groth16 = await buildGroth16()
netId = await web3.eth.net.getId()
if (noteNetId && Number(noteNetId) !== netId) {
throw new Error('This note is for a different network. Specify the --rpc option explicitly')
}
isLocalRPC = netId > 42
if (isLocalRPC) {
tornadoAddress = currency === 'eth' ? contractJson.networks[netId].address : erc20tornadoJson.networks[netId].address
tokenAddress = currency !== 'eth' ? erc20ContractJson.networks[netId].address : null
senderAccount = (await web3.eth.getAccounts())[0]
} else {
try{
tornadoAddress = config.deployments[`netId${netId}`][currency].instanceAddress[amount]
if (!tornadoAddress) {
throw new Error()
}
tokenAddress = config.deployments[`netId${netId}`][currency].tokenAddress
} catch(e) {
console.error('There is no such tornado instance, check the currency and amount you provide')
process.exit(1)
}
}
tornado = new web3.eth.Contract(contractJson.abi, tornadoAddress)
erc20 = currency !== 'eth' ? new web3.eth.Contract(erc20ContractJson.abi, tokenAddress) : {}
}
async function main() {
if (inBrowser) {
const instance = { currency: 'eth', amount: '0.1' }
await init(instance)
window.deposit = async () => {
await deposit(instance)
}
window.withdraw = async () => {
const noteString = prompt('Enter the note to withdraw')
const recipient = (await web3.eth.getAccounts())[0]
const { currency, amount, netId, deposit } = parseNote(noteString)
await init({ noteNetId: netId, currency, amount })
await withdraw({ deposit, currency, amount, recipient })
}
} else {
program
.option('-r, --rpc <URL>', 'The RPC, CLI should interact with', 'http://localhost:8545')
.option('-R, --relayer <URL>', 'Withdraw via relayer')
program
.command('deposit <currency> <amount>')
.description('Submit a deposit of specified currency and amount from default eth account and return the resulting note. The currency is one of (ETH|DAI|cDAI|USDC|cUSDC|USDT). The amount depends on currency, see config.js file or visit https://tornado.cash.')
.action(async (currency, amount) => {
currency = currency.toLowerCase()
await init({ rpc: program.rpc, currency, amount })
await deposit({ currency, amount })
})
program
.command('withdraw <note> <recipient> [ETH_purchase]')
.description('Withdraw a note to a recipient account using relayer or specified private key. You can exchange some of your deposit`s tokens to ETH during the withdrawal by specifing ETH_purchase (e.g. 0.01) to pay for gas in future transactions. Also see the --relayer option.')
.action(async (noteString, recipient, refund) => {
const { currency, amount, netId, deposit } = parseNote(noteString)
await init({ rpc: program.rpc, noteNetId: netId, currency, amount })
await withdraw({ deposit, currency, amount, recipient, refund, relayerURL: program.relayer })
})
program
.command('balance <address> [token_address]')
.description('Check ETH and ERC20 balance')
.action(async (address, tokenAddress) => {
await init({ rpc: program.rpc })
await printETHBalance({ address, name: '' })
if (tokenAddress) {
await printERC20Balance({ address, name: '', tokenAddress })
}
})
program
.command('test')
.description('Perform an automated test. It deposits and withdraws one ETH and one ERC20 note. Uses ganache.')
.action(async () => {
console.log('Start performing ETH deposit-withdraw test')
let currency = 'eth'
let amount = '0.1'
await init({ rpc: program.rpc, currency, amount })
let noteString = await deposit({ currency, amount })
let parsedNote = parseNote(noteString)
await withdraw({ deposit: parsedNote.deposit, currency, amount, recipient: senderAccount, relayerURL: program.relayer })
console.log('\nStart performing DAI deposit-withdraw test')
currency = 'dai'
amount = '100'
await init({ rpc: program.rpc, currency, amount })
noteString = await deposit({ currency, amount })
;(parsedNote = parseNote(noteString))
await withdraw({ deposit: parsedNote.deposit, currency, amount, recipient: senderAccount, refund: '0.02', relayerURL: program.relayer })
})
try {
await program.parseAsync(process.argv)
process.exit(0)
} catch(e) {
console.log('Error:', e)
process.exit(1)
}
}
}
main()