WIP

cli.js

@@ -12,8 +12,8 @@ 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, ETH_AMOUNT, EMPTY_ELEMENT
+let web3, mixer, erc20mixer, circuit, proving_key, groth16, erc20
+let MERKLE_TREE_HEIGHT, ETH_AMOUNT, EMPTY_ELEMENT, ERC20_TOKEN
 const inBrowser = (typeof window !== 'undefined')
 
 const rbigint = (nbytes) => snarkjs.bigInt.leBuff2int(crypto.randomBytes(nbytes))
@@ -37,6 +37,78 @@ async function deposit() {
   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 })
+  const allowance = await erc20.methods.allowance(account, erc20mixer.address).call()
+  console.log('erc20mixer allowance', allowance.toString(10))
+
+  await erc20.methods.approve(erc20mixer.address, tokenAmount).send({ from: account, gas:1e6 })
+
+  const deposit = createDeposit(rbigint(31), rbigint(31))
+  await erc20mixer.methods.deposit('0x' + deposit.commitment.toString(16)).send({ value: ETH_AMOUNT, from: account, gas:1e6 })
+
+  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) {
+  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 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 getBalance(receiver) {
   const balance = await web3.eth.getBalance(receiver)
   console.log('Balance is ', web3.utils.fromWei(balance))
@@ -96,7 +168,7 @@ async function withdraw(note, receiver) {
 }
 
 async function init() {
-  let contractJson
+  let contractJson, erc20ContractJson, erc20mixerJson
   if (inBrowser) {
     web3 = new Web3(window.web3.currentProvider, null, { transactionConfirmationBlocks: 1 })
     contractJson = await (await fetch('build/contracts/ETHMixer.json')).json()
@@ -114,12 +186,25 @@ async function init() {
     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()
-  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 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')
 }
 
@@ -167,6 +252,13 @@ if (inBrowser) {
       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)})