tornado-core/cli.js
2019-10-06 04:01:04 +03:00

345 lines
13 KiB
JavaScript
Executable File

#!/usr/bin/env node
// Temporary demo client
// Works both in browser and node.js
const fs = require('fs')
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')
let web3, mixer, erc20mixer, circuit, proving_key, groth16, erc20
let MERKLE_TREE_HEIGHT, ETH_AMOUNT, EMPTY_ELEMENT, ERC20_TOKEN
const inBrowser = (typeof window !== 'undefined')
/** 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]
/**
* Create deposit object from secret and nullifier
*/
function createDeposit(nullifier, secret) {
let deposit = { nullifier, secret }
deposit.preimage = Buffer.concat([deposit.nullifier.leInt2Buff(31), deposit.secret.leInt2Buff(31)])
deposit.commitment = pedersenHash(deposit.preimage)
return deposit
}
/**
* Make a deposit
* @returns {Promise<string>}
*/
async function deposit() {
const deposit = createDeposit(rbigint(31), rbigint(31))
console.log('Submitting deposit transaction')
await mixer.methods.deposit('0x' + deposit.commitment.toString(16)).send({ value: ETH_AMOUNT, from: (await web3.eth.getAccounts())[0], gas:4e6 })
const note = '0x' + deposit.preimage.toString('hex')
console.log('Your note:', note)
return note
}
async function depositErc20() {
const account = (await web3.eth.getAccounts())[0]
const tokenAmount = process.env.TOKEN_AMOUNT
await erc20.methods.mint(account, tokenAmount).send({ from: account, gas:1e6 })
await erc20.methods.approve(erc20mixer.address, tokenAmount).send({ from: account, gas:1e6 })
const allowance = await erc20.methods.allowance(account, erc20mixer.address).call()
console.log('erc20mixer allowance', allowance.toString(10))
const deposit = createDeposit(rbigint(31), rbigint(31))
await erc20mixer.methods.deposit('0x' + deposit.commitment.toString(16)).send({ value: ETH_AMOUNT, from: account, gas:4e6 })
const balance = await erc20.methods.balanceOf(erc20mixer.address).call()
console.log('erc20mixer balance', balance.toString(10))
const note = '0x' + deposit.preimage.toString('hex')
console.log('Your note:', note)
return note
}
async function withdrawErc20(note, receiver, relayer) {
let buf = Buffer.from(note.slice(2), 'hex')
let deposit = createDeposit(bigInt.leBuff2int(buf.slice(0, 31)), bigInt.leBuff2int(buf.slice(31, 62)))
console.log('Getting current state from mixer contract')
const events = await erc20mixer.getPastEvents('Deposit', { fromBlock: erc20mixer.deployedBlock, toBlock: 'latest' })
let leafIndex
const commitment = deposit.commitment.toString(16).padStart('66', '0x000000')
const leaves = events
.sort((a, b) => a.returnValues.leafIndex.sub(b.returnValues.leafIndex))
.map(e => {
if (e.returnValues.commitment.eq(commitment)) {
leafIndex = e.returnValues.leafIndex.toNumber()
}
return e.returnValues.commitment
})
const tree = new merkleTree(MERKLE_TREE_HEIGHT, EMPTY_ELEMENT, leaves)
const validRoot = await erc20mixer.methods.isKnownRoot(await tree.root()).call()
const nullifierHash = pedersenHash(deposit.nullifier.leInt2Buff(31))
const nullifierHashToCheck = nullifierHash.toString(16).padStart('66', '0x000000')
const isSpent = await erc20mixer.methods.isSpent(nullifierHashToCheck).call()
assert(validRoot === true)
assert(isSpent === false)
assert(leafIndex >= 0)
const { root, path_elements, path_index } = await tree.path(leafIndex)
// Circuit input
const input = {
// public
root: root,
nullifierHash,
receiver: bigInt(receiver),
relayer: bigInt(relayer),
fee: bigInt(web3.utils.toWei('0.01')),
// private
nullifier: deposit.nullifier,
secret: deposit.secret,
pathElements: path_elements,
pathIndex: path_index,
}
console.log('Generating SNARK proof')
console.time('Proof time')
const proofData = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
const { proof, publicSignals } = websnarkUtils.toSolidityInput(proofData)
console.timeEnd('Proof time')
console.log('Submitting withdraw transaction')
await erc20mixer.methods.withdraw(proof, publicSignals).send({ from: (await web3.eth.getAccounts())[0], gas: 4e6 })
console.log('Done')
}
async function getBalance(receiver) {
const balance = await web3.eth.getBalance(receiver)
console.log('Balance is ', web3.utils.fromWei(balance))
}
async function getBalanceErc20(receiver, relayer) {
const balanceReceiver = await web3.eth.getBalance(receiver)
const balanceRelayer = await web3.eth.getBalance(relayer)
const tokenBalanceReceiver = await erc20.methods.balanceOf(receiver).call()
const tokenBalanceRelayer = await erc20.methods.balanceOf(relayer).call()
console.log('Receiver eth Balance is ', web3.utils.fromWei(balanceReceiver))
console.log('Relayer eth Balance is ', web3.utils.fromWei(balanceRelayer))
console.log('Receiver token Balance is ', web3.utils.fromWei(tokenBalanceReceiver.toString()))
console.log('Relayer token Balance is ', web3.utils.fromWei(tokenBalanceRelayer.toString()))
}
async function withdraw(note, receiver) {
// Decode hex string and restore the deposit object
let buf = Buffer.from(note.slice(2), 'hex')
let deposit = createDeposit(bigInt.leBuff2int(buf.slice(0, 31)), bigInt.leBuff2int(buf.slice(31, 62)))
const nullifierHash = pedersenHash(deposit.nullifier.leInt2Buff(31))
const paddedNullifierHash = nullifierHash.toString(16).padStart('66', '0x000000')
const paddedCommitment = deposit.commitment.toString(16).padStart('66', '0x000000')
// Get all deposit events from smart contract and assemble merkle tree from them
console.log('Getting current state from mixer contract')
const events = await mixer.getPastEvents('Deposit', { fromBlock: mixer.deployedBlock, toBlock: 'latest' })
const leaves = events
.sort((a, b) => a.returnValues.leafIndex.sub(b.returnValues.leafIndex)) // Sort events in chronological order
.map(e => e.returnValues.commitment)
const tree = new merkleTree(MERKLE_TREE_HEIGHT, EMPTY_ELEMENT, leaves)
// Find current commitment in the tree
let depositEvent = events.find(e => e.returnValues.commitment.eq(paddedCommitment))
let leafIndex = depositEvent ? depositEvent.returnValues.leafIndex.toNumber() : -1
// Validate that our data is correct
const isValidRoot = await mixer.methods.isKnownRoot(await tree.root()).call()
const isSpent = await mixer.methods.isSpent(paddedNullifierHash).call()
assert(isValidRoot === true) // Merkle tree assembled correctly
assert(isSpent === false) // The note is not spent
assert(leafIndex >= 0) // Our deposit is present in the tree
// Compute merkle proof of our commitment
const { root, path_elements, path_index } = await tree.path(leafIndex)
// Prepare circuit input
const input = {
// Public snark inputs
root: root,
nullifierHash,
receiver: bigInt(receiver),
relayer: bigInt(0),
fee: bigInt(0),
// Private snark inputs
nullifier: deposit.nullifier,
secret: deposit.secret,
pathElements: path_elements,
pathIndex: path_index,
}
console.log('Generating SNARK proof')
console.time('Proof time')
const proofData = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
const { proof, publicSignals } = websnarkUtils.toSolidityInput(proofData)
console.timeEnd('Proof time')
console.log('Submitting withdraw transaction')
await mixer.methods.withdraw(proof, publicSignals).send({ from: (await web3.eth.getAccounts())[0], gas: 4e6 })
console.log('Done')
}
/**
* Init web3, contracts, and snark
*/
async function init() {
let contractJson, erc20ContractJson, erc20mixerJson
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/ETHMixer.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 = 16
ETH_AMOUNT = 1e18
EMPTY_ELEMENT = 1
} else {
// Initialize from local node
web3 = new Web3('http://localhost:8545', null, { transactionConfirmationBlocks: 1 })
contractJson = require('./build/contracts/ETHMixer.json')
circuit = require('./build/circuits/withdraw.json')
proving_key = fs.readFileSync('build/circuits/withdraw_proving_key.bin').buffer
require('dotenv').config()
MERKLE_TREE_HEIGHT = process.env.MERKLE_TREE_HEIGHT
ETH_AMOUNT = process.env.ETH_AMOUNT
EMPTY_ELEMENT = process.env.EMPTY_ELEMENT
ERC20_TOKEN = process.env.ERC20_TOKEN
erc20ContractJson = require('./build/contracts/ERC20Mock.json')
erc20mixerJson = require('./build/contracts/ERC20Mixer.json')
}
groth16 = await buildGroth16()
let netId = await web3.eth.net.getId()
if (contractJson.networks[netId]) {
const tx = await web3.eth.getTransaction(contractJson.networks[netId].transactionHash)
mixer = new web3.eth.Contract(contractJson.abi, contractJson.networks[netId].address)
mixer.deployedBlock = tx.blockNumber
}
const tx3 = await web3.eth.getTransaction(erc20mixerJson.networks[netId].transactionHash)
erc20mixer = new web3.eth.Contract(erc20mixerJson.abi, erc20mixerJson.networks[netId].address)
erc20mixer.deployedBlock = tx3.blockNumber
if(ERC20_TOKEN === '') {
erc20 = new web3.eth.Contract(erc20ContractJson.abi, erc20ContractJson.networks[netId].address)
const tx2 = await web3.eth.getTransaction(erc20ContractJson.networks[netId].transactionHash)
erc20.deployedBlock = tx2.blockNumber
}
console.log('Loaded')
}
// ========== CLI related stuff below ==============
function printHelp(code = 0) {
console.log(`Usage:
Submit a deposit from default eth account and return the resulting note
$ ./cli.js deposit
Withdraw a note to 'receiver' account
$ ./cli.js withdraw <note> <receiver>
Check address balance
$ ./cli.js balance <address>
Example:
$ ./cli.js deposit
...
Your note: 0x1941fa999e2b4bfeec3ce53c2440c3bc991b1b84c9bb650ea19f8331baf621001e696487e2a2ee54541fa12f49498d71e24d00b1731a8ccd4f5f5126f3d9f400
$ ./cli.js withdraw 0x1941fa999e2b4bfeec3ce53c2440c3bc991b1b84c9bb650ea19f8331baf621001e696487e2a2ee54541fa12f49498d71e24d00b1731a8ccd4f5f5126f3d9f400 0xee6249BA80596A4890D1BD84dbf5E4322eA4E7f0
`)
process.exit(code)
}
if (inBrowser) {
window.deposit = deposit
window.withdraw = async () => {
const note = prompt('Enter the note to withdraw')
const receiver = (await web3.eth.getAccounts())[0]
await withdraw(note, receiver)
}
init()
} else {
const args = process.argv.slice(2)
if (args.length === 0) {
printHelp()
} else {
switch (args[0]) {
case 'deposit':
if (args.length === 1) {
init().then(() => deposit()).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
}
else
printHelp(1)
break
case 'depositErc20':
if (args.length === 1) {
init().then(() => depositErc20()).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
}
else
printHelp(1)
break
case 'balance':
if (args.length === 2 && /^0x[0-9a-fA-F]{40}$/.test(args[1])) {
init().then(() => getBalance(args[1])).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
} else
printHelp(1)
break
case 'balanceErc20':
if (args.length === 3 && /^0x[0-9a-fA-F]{40}$/.test(args[1]) && /^0x[0-9a-fA-F]{40}$/.test(args[2])) {
init().then(() => getBalanceErc20(args[1], args[2])).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
} else
printHelp(1)
break
case 'withdraw':
if (args.length === 3 && /^0x[0-9a-fA-F]{124}$/.test(args[1]) && /^0x[0-9a-fA-F]{40}$/.test(args[2])) {
init().then(() => withdraw(args[1], args[2])).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
}
else
printHelp(1)
break
case 'withdrawErc20':
if (args.length === 4 && /^0x[0-9a-fA-F]{124}$/.test(args[1]) && /^0x[0-9a-fA-F]{40}$/.test(args[2]) && /^0x[0-9a-fA-F]{40}$/.test(args[3])) {
init().then(() => withdrawErc20(args[1], args[2], args[3])).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
}
else
printHelp(1)
break
case 'test':
if (args.length === 1) {
(async () => {
await init()
const account = (await web3.eth.getAccounts())[0]
const note = await deposit()
await withdraw(note, account)
const note2 = await deposit()
await withdraw(note2, account, account)
process.exit(0)
})()
}
else
printHelp(1)
break
default:
printHelp(1)
}
}
}