tornado-core/cli.js
2019-08-01 17:49:34 +03:00

201 lines
6.9 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, circuit, proving_key, groth16
let MERKLE_TREE_HEIGHT, AMOUNT, EMPTY_ELEMENT
const inBrowser = (typeof window !== 'undefined')
const rbigint = (nbytes) => snarkjs.bigInt.leBuff2int(crypto.randomBytes(nbytes))
const pedersenHash = (data) => circomlib.babyJub.unpackPoint(circomlib.pedersenHash.hash(data))[0]
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
}
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: AMOUNT, from: (await web3.eth.getAccounts())[0], gas:1e6 })
const note = '0x' + deposit.preimage.toString('hex')
console.log('Your note:', note)
return note
}
async function getBalance(receiver) {
const balance = await web3.eth.getBalance(receiver)
console.log('Balance is ', web3.utils.fromWei(balance))
}
async function withdraw(note, receiver) {
let buf = Buffer.from(note.slice(2), 'hex')
let deposit = createDeposit(bigInt.leBuff2int(buf.slice(0, 32)), bigInt.leBuff2int(buf.slice(32, 64)))
console.log('Getting current state from mixer contract')
const events = await mixer.getPastEvents('Deposit', { fromBlock: mixer.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 mixer.methods.isKnownRoot(await tree.root()).call()
const nullifierHash = pedersenHash(deposit.nullifier.leInt2Buff(31))
const nullifierHashToCheck = nullifierHash.toString(16).padStart('66', '0x000000')
const isSpent = await mixer.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),
fee: bigInt(0),
// private
nullifier: deposit.nullifier,
secret: deposit.secret,
pathElements: path_elements,
pathIndex: path_index,
}
console.log('Generating SNARK proof')
console.time('Proof time')
const proof = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
const { pi_a, pi_b, pi_c, publicSignals } = websnarkUtils.toSolidityInput(proof)
console.timeEnd('Proof time')
console.log('Submitting withdraw transaction')
await mixer.methods.withdraw(pi_a, pi_b, pi_c, publicSignals).send({ from: (await web3.eth.getAccounts())[0], gas: 1e6 })
console.log('Done')
}
async function init() {
let contractJson
if (inBrowser) {
web3 = new Web3(window.web3.currentProvider, null, { transactionConfirmationBlocks: 1 })
contractJson = await (await fetch('build/contracts/Mixer.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
AMOUNT = 1e18
EMPTY_ELEMENT = 0
} else {
web3 = new Web3('http://localhost:8545', null, { transactionConfirmationBlocks: 1 })
contractJson = require('./build/contracts/Mixer.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
AMOUNT = process.env.AMOUNT
EMPTY_ELEMENT = process.env.EMPTY_ELEMENT
}
groth16 = await buildGroth16()
let netId = await web3.eth.net.getId()
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
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 'balance':
if (args.length === 2 && /^0x[0-9a-fA-F]{40}$/.test(args[1])) {
init().then(() => getBalance(args[1])).then(() => process.exit(0)).catch(err => {console.log(err); process.exit(1)})
} else
printHelp(1)
break
case 'withdraw':
if (args.length === 3 && /^0x[0-9a-fA-F]{128}$/.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 'auto':
if (args.length === 1) {
(async () => {
await init()
const note = await deposit()
await withdraw(note, (await web3.eth.getAccounts())[0])
process.exit(0)
})()
}
else
printHelp(1)
break
default:
printHelp(1)
}
}
}