first deposit

.editorconfig

@@ -2,7 +2,7 @@ root = true
 
 [*]
 indent_style = space
-indent_size = 2
+indent_size = 4
 end_of_line = lf
 charset = utf-8
 trim_trailing_whitespace = true

TODO

@@ -1 +1,3 @@
-* update verifier
+* update verifier version
+* shuffle outputs
+* 

circuits/merkleTree.circom

@@ -29,10 +29,11 @@ template DualMux() {
 // pathIndices input is an array of 0/1 selectors telling whether given pathElement is on the left or right side of merkle path
 template MerkleTree(levels) {
     signal input leaf;
-    signal input root;
     signal input pathElements[levels];
     signal input pathIndices;
 
+    signal output root;
+
     component selectors[levels];
     component hashers[levels];
 
@@ -50,5 +51,5 @@ template MerkleTree(levels) {
         hashers[i].right <== selectors[i].out[1];
     }
 
-    root === hashers[levels - 1].hash;
+    root <== hashers[levels - 1].hash;
 }

circuits/transaction.circom

@@ -38,6 +38,7 @@ template Transaction(levels, zeroLeaf) {
     // data for 2 transaction outputs
     signal private input outAmount[2];
     signal private input outBlinding[2];
+    signal private input outPubkey[2];
     signal private input outPathIndices;
     signal private input outPathElements[levels - 1];
 
@@ -88,7 +89,7 @@ template Transaction(levels, zeroLeaf) {
         outUtxoHasher[tx] = TransactionHasher();
         outUtxoHasher[tx].amount <== outAmount[tx];
         outUtxoHasher[tx].blinding <== outBlinding[tx];
-        outUtxoHasher[tx].publicKey <== keypair.publicKey;
+        outUtxoHasher[tx].publicKey <== outPubkey[tx];
         outUtxoHasher[tx].commitment === outputCommitment[tx];
 
         // Check that amount fits into 248 bits to prevent overflow
@@ -120,4 +121,4 @@ template Transaction(levels, zeroLeaf) {
     }
 }
 
-component main = Transaction(5, 3193090221241211970002919215846211184824251841300455796635909287157453409439);
+component main = Transaction(5, 16923532097304556005972200564242292693309333953544141029519619077135960040221);

circuits/utils.circom

@@ -7,8 +7,11 @@ template Keypair() {
     signal input privateKey;
     signal output publicKey;
 
-    publicKey <== privateKey;
-    // todo
+    component hasher = MiMCSponge(1, 1);
+    hasher.ins[0] <== privateKey;
+    hasher.k <== 0;
+
+    publicKey <== hasher.outs[0];
 }
 
 template TransactionHasher() {

contracts/TornadoPool.sol

@@ -34,8 +34,9 @@ contract TornadoPool is ReentrancyGuard {
     @dev The constructor
     @param _verifier the address of SNARK verifier for this contract
   */
-  constructor(IVerifier _verifier) public {
+  constructor(IVerifier _verifier, bytes32 _currentRoot) public {
     verifier = _verifier;
+    currentRoot = _currentRoot;
   }
 
   function transaction(
@@ -83,8 +84,8 @@ contract TornadoPool is ReentrancyGuard {
       transfer(_relayer, _fee);
     }
 
-    emit NewCommitment(_outputCommitments[0], currentDepositIndex++);
-    emit NewCommitment(_outputCommitments[1], currentDepositIndex++);
+    emit NewCommitment(_outputCommitments[0], currentCommitmentIndex++);
+    emit NewCommitment(_outputCommitments[1], currentCommitmentIndex++);
     emit NewNullifier(_inputNullifiers[0]);
     emit NewNullifier(_inputNullifiers[1]);
     // emit Transaction();

lib/merkleTree.js

@@ -0,0 +1,201 @@
+const jsStorage = require('./storage')
+const hasherImpl = require('./mimc')
+
+class MerkleTree {
+
+  constructor(n_levels, defaultElements, prefix, storage, hasher) {
+    this.prefix = prefix
+    this.storage = storage || new jsStorage()
+    this.hasher = hasher || new hasherImpl()
+    this.n_levels = n_levels
+    this.zero_values = []
+    this.totalElements = 0
+
+    let current_zero_value = '21663839004416932945382355908790599225266501822907911457504978515578255421292'
+    this.zero_values.push(current_zero_value)
+    for (let i = 0; i < n_levels; i++) {
+      current_zero_value = this.hasher.hash(i, current_zero_value, current_zero_value)
+      this.zero_values.push(
+        current_zero_value.toString(),
+      )
+    }
+    if (defaultElements) {
+      let level = 0
+      this.totalElements = defaultElements.length
+      defaultElements.forEach((element, i) => {
+        this.storage.put(MerkleTree.index_to_key(prefix, level, i), element)
+      })
+      level++
+      let numberOfElementsInLevel = Math.ceil(defaultElements.length / 2)
+      for (level; level <= this.n_levels; level++) {
+        for(let i = 0; i < numberOfElementsInLevel; i++) {
+          const leftKey = MerkleTree.index_to_key(prefix, level - 1, 2 * i)
+          const rightKey = MerkleTree.index_to_key(prefix, level - 1, 2 * i + 1)
+
+          const left = this.storage.get(leftKey)
+          const right = this.storage.get_or_element(rightKey, this.zero_values[level - 1])
+
+          const subRoot = this.hasher.hash(null, left, right)
+          this.storage.put(MerkleTree.index_to_key(prefix, level, i), subRoot)
+        }
+        numberOfElementsInLevel = Math.ceil(numberOfElementsInLevel / 2)
+      }
+    }
+  }
+
+  static index_to_key(prefix, level, index) {
+    const key = `${prefix}_tree_${level}_${index}`
+    return key
+  }
+
+  async root() {
+    let root = await this.storage.get_or_element(
+      MerkleTree.index_to_key(this.prefix, this.n_levels, 0),
+      this.zero_values[this.n_levels],
+    )
+
+    return root
+  }
+
+  async path(index) {
+    class PathTraverser {
+      constructor(prefix, storage, zero_values) {
+        this.prefix = prefix
+        this.storage = storage
+        this.zero_values = zero_values
+        this.path_elements = []
+        this.path_index = []
+      }
+
+      async handle_index(level, element_index, sibling_index) {
+        const sibling = await this.storage.get_or_element(
+          MerkleTree.index_to_key(this.prefix, level, sibling_index),
+          this.zero_values[level],
+        )
+        this.path_elements.push(sibling)
+        this.path_index.push(element_index % 2)
+      }
+    }
+    index = Number(index)
+    let traverser = new PathTraverser(this.prefix, this.storage, this.zero_values)
+    const root = await this.storage.get_or_element(
+      MerkleTree.index_to_key(this.prefix, this.n_levels, 0),
+      this.zero_values[this.n_levels],
+    )
+
+    const element = await this.storage.get_or_element(
+      MerkleTree.index_to_key(this.prefix, 0, index),
+      this.zero_values[0],
+    )
+
+    await this.traverse(index, traverser)
+    return {
+      root,
+      path_elements: traverser.path_elements,
+      path_index: traverser.path_index,
+      element
+    }
+  }
+
+  async update(index, element, insert = false) {
+    if (!insert && index >= this.totalElements) {
+      throw Error('Use insert method for new elements.')
+    } else if(insert && index < this.totalElements) {
+      throw Error('Use update method for existing elements.')
+    }
+    try {
+      class UpdateTraverser {
+        constructor(prefix, storage, hasher, element, zero_values) {
+          this.prefix = prefix
+          this.current_element = element
+          this.zero_values = zero_values
+          this.storage = storage
+          this.hasher = hasher
+          this.key_values_to_put = []
+        }
+
+        async handle_index(level, element_index, sibling_index) {
+          if (level == 0) {
+            this.original_element = await this.storage.get_or_element(
+              MerkleTree.index_to_key(this.prefix, level, element_index),
+              this.zero_values[level],
+            )
+          }
+          const sibling = await this.storage.get_or_element(
+            MerkleTree.index_to_key(this.prefix, level, sibling_index),
+            this.zero_values[level],
+          )
+          let left, right
+          if (element_index % 2 == 0) {
+            left = this.current_element
+            right = sibling
+          } else {
+            left = sibling
+            right = this.current_element
+          }
+
+          this.key_values_to_put.push({
+            key: MerkleTree.index_to_key(this.prefix, level, element_index),
+            value: this.current_element,
+          })
+          this.current_element = this.hasher.hash(level, left, right)
+        }
+      }
+      let traverser = new UpdateTraverser(
+        this.prefix,
+        this.storage,
+        this.hasher,
+        element,
+        this.zero_values
+      )
+
+      await this.traverse(index, traverser)
+      traverser.key_values_to_put.push({
+        key: MerkleTree.index_to_key(this.prefix, this.n_levels, 0),
+        value: traverser.current_element,
+      })
+
+      await this.storage.put_batch(traverser.key_values_to_put)
+    } catch(e) {
+      console.error(e)
+    }
+  }
+
+  async insert(element) {
+    const index = this.totalElements
+    await this.update(index, element, true)
+    this.totalElements++
+  }
+
+  // todo it can be mode optimal
+  async insertPair(first, second) {
+    await insert(first)
+    await insert(second)
+  }
+
+  async traverse(index, handler) {
+    let current_index = index
+    for (let i = 0; i < this.n_levels; i++) {
+      let sibling_index = current_index
+      if (current_index % 2 == 0) {
+        sibling_index += 1
+      } else {
+        sibling_index -= 1
+      }
+      await handler.handle_index(i, current_index, sibling_index)
+      current_index = Math.floor(current_index / 2)
+    }
+  }
+
+  getIndexByElement(element) {
+    for(let i = this.totalElements - 1; i >= 0; i--) {
+      const elementFromTree = this.storage.get(MerkleTree.index_to_key(this.prefix, 0, i))
+      if (elementFromTree === element) {
+        return i
+      }
+    }
+    return false
+  }
+}
+
+module.exports = MerkleTree

lib/mimc.js

@@ -0,0 +1,17 @@
+const circomlib = require('circomlib')
+const mimcsponge = circomlib.mimcsponge
+const snarkjs = require('snarkjs')
+
+const bigInt = snarkjs.bigInt
+
+class MimcSpongeHasher {
+  hash(level, left, right) {
+    return mimcsponge.multiHash([bigInt(left), bigInt(right)]).toString()
+  }
+
+  hashArray(items) {
+    return mimcsponge.multiHash(items.map(item => bigInt(item))).toString()
+  }
+}
+
+module.exports = MimcSpongeHasher

lib/storage.js

@@ -0,0 +1,39 @@
+
+
+class JsStorage {
+  constructor() {
+    this.db = {}
+  }
+
+  get(key) {
+    return this.db[key]
+  }
+
+  get_or_element(key, defaultElement) {
+    const element = this.db[key]
+    if (element === undefined) {
+      return defaultElement
+    } else {
+      return element
+    }
+  }
+
+  put(key, value) {
+    if (key === undefined || value === undefined) {
+      throw Error('key or value is undefined')
+    }
+    this.db[key] = value
+  }
+
+  del(key) {
+    delete this.db[key]
+  }
+
+  put_batch(key_values) {
+    key_values.forEach(element => {
+      this.db[element.key] = element.value
+    })
+  }
+}
+
+module.exports = JsStorage

migrations/2_deploy_pool.js

@@ -1,11 +1,19 @@
 /* global artifacts */
 const Verifier = artifacts.require('Verifier')
 const TornadoPool = artifacts.require('TornadoPool')
+const MERKLE_TREE_HEIGHT = 5
+const MerkleTree = require('../lib/merkleTree')
+const { bigInt } = require('snarkjs')
+const toHex = (number, length = 32) => '0x' + (number instanceof Buffer ? number.toString('hex') : bigInt(number).toString(16)).padStart(length * 2, '0')
+
 
 module.exports = function(deployer, network, accounts) {
   return deployer.then(async () => {
+    const tree = new MerkleTree(MERKLE_TREE_HEIGHT)
+    const root = await tree.root()
     const verifier = await Verifier.deployed()
-    const tornado = await deployer.deploy(TornadoPool, verifier.address)
+
+    const tornado = await deployer.deploy(TornadoPool, verifier.address, toHex(root))
     console.log('TornadoPool\'s address ', tornado.address)
   })
 }

src/index.js

@@ -1,31 +1,39 @@
-const MERKLE_TREE_HEIGHT = 10;
+const MerkleTree = require('../lib/merkleTree')
+const fs = require('fs')
+const { bigInt, stringifyBigInts } = require('snarkjs')
+const crypto = require('crypto')
+const Hasher = require('../lib/mimc')
+const Web3 = require('web3')
+const buildGroth16 = require('websnark/src/groth16')
+const websnarkUtils = require('websnark/src/utils')
 
-function rbigint(bytes = 31) {
+let contract, web3, circuit, proving_key, groth16
+const hasher = new Hasher()
 
-}
+// console.log(hasher.hashArray(['21663839004416932945382355908790599225266501822907911457504978515578255421292', '21663839004416932945382355908790599225266501822907911457504978515578255421292']))
 
-function randomBoolArray(length) {
+const MERKLE_TREE_HEIGHT = 5
+const RPC_URL = 'http://localhost:8545'
 
-}
+/** Generate random number of specified byte length */
+const rbigint = (nbytes = 31) => bigInt.leBuff2int(crypto.randomBytes(nbytes))
 
-function randomArray(length) {
+/** BigNumber to hex string of specified length */
+const toHex = (number, length = 32) => '0x' + (number instanceof Buffer ? number.toString('hex') : bigInt(number).toString(16)).padStart(length * 2, '0')
 
-}
-
-function hash(dataArray) {
-    for(let item of dataArray) {
-
-    }
-}
 
 function merklePathIndicesToBigint(indexArray) {
-
+  let result = 0
+  for(let item of indexArray) {
+    result = (result << 1) + item
+  }
+  return result
 }
 
 function fromPrivkey(privkey) {
     return {
         privkey,
-        pubkey: privkey,
+        pubkey: hasher.hashArray([privkey]),
     }
 }
 
@@ -34,7 +42,14 @@ function randomKeypair() {
 }
 
 function createZeroUtxo(keypair) {
-    return createUtxo(0, rbigint(), keypair.pubkey, keypair.privkey, randomBoolArray(MERKLE_TREE_HEIGHT), randomArray(MERKLE_TREE_HEIGHT))
+  return createUtxo(
+      0,
+      rbigint(),
+      keypair.pubkey,
+      keypair.privkey,
+      Array(MERKLE_TREE_HEIGHT).fill(0),
+      Array(MERKLE_TREE_HEIGHT).fill(0)
+  )
 }
 
 function createOutput(amount, pubkey) {
@@ -51,9 +66,9 @@ function createInput(amount, blinding, pubkey, privkey, merklePathIndices, merkl
 /// unsafe function without sanity checks
 function createUtxo(amount, blinding, pubkey, privkey, merklePathIndices, merklePathElements) {
     let utxo = { amount, blinding, pubkey, privkey, merklePathIndices, merklePathElements }
-    utxo.commitment = hash([amount, blinding, pubkey])
+    utxo.commitment = hasher.hashArray([amount, blinding, pubkey])
     if (privkey) {
-        utxo.nullifier = hash([commitment, merklePathIndicesToBigint(merklePathIndices), privkey])
+        utxo.nullifier = hasher.hashArray([utxo.commitment, merklePathIndicesToBigint(merklePathIndices), privkey])
     }
     return utxo
 }
@@ -62,7 +77,7 @@ function createDeposit(amount, pubkey) {
     const keypair = randomKeypair()
     const tx = {
         inputs: [createZeroUtxo(keypair), createZeroUtxo(keypair)],
-        outputs: [createOutput(amount, pubkey), createZeroUtxo()], // todo shuffle
+        outputs: [createOutput(amount, pubkey), createZeroUtxo(keypair)], // todo shuffle
     }
     return tx;
 }
@@ -73,28 +88,38 @@ async function buildMerkleTree() {
     const leaves = events
       .sort((a, b) => a.returnValues.index - b.returnValues.index) // todo sort by event date
       .map(e => e.returnValues.commitment)
-    return new merkleTree(MERKLE_TREE_HEIGHT, leaves)
+    return new MerkleTree(MERKLE_TREE_HEIGHT, leaves)
 }
 
-function insertTransaction(tree, tx) {
-    let path = await tree.insertPair(tx.outputs[0].commitment, tx.outputs[1].commitment)
-
-    tx.outputs[0].merklePath = [...path, 0]
-    tx.outputs[1].merklePath = [...path, 1]
+async function insertOutput(tree, output) {
+    await tree.insert(output.commitment)
+    let { path_elements, path_index } = await tree.path(tree.totalElements - 1)
+    output.merklePathIndices = path_index
+    output.merklePathElements = path_elements
 }
 
 async function main() {
-    const amount = 1e6;
+    web3 = new Web3(new Web3.providers.HttpProvider(RPC_URL, { timeout: 5 * 60 * 1000 }), null, { transactionConfirmationBlocks: 1 })
+    circuit = require('../build/circuits/transaction.json')
+    proving_key = fs.readFileSync('../build/circuits/transaction_proving_key.bin').buffer
+    groth16 = await buildGroth16()
+    netId = await web3.eth.net.getId()
+    const contractData = require('../build/contracts/TornadoPool.json')
+    contract = new web3.eth.Contract(contractData.abi, contractData.networks[netId].address)
+    web3.eth.defaultAccount = (await web3.eth.getAccounts())[0]
 
+    const amount = 1e6;
     const tree = await buildMerkleTree()
-    const oldRoot = tree.root;
+    const oldRoot = await tree.root()
     const keypair = randomKeypair()
     const tx = createDeposit(amount, keypair.pubkey)
-    insertTransaction(tree, tx)
+    await insertOutput(tree, tx.outputs[0])
+    await insertOutput(tree, tx.outputs[1])
+    console.log('Note', tx.outputs[0])
 
     let input = {
         root: oldRoot,
-        newRoot: tree.root,
+        newRoot: await tree.root(),
         inputNullifier: [tx.inputs[0].nullifier, tx.inputs[1].nullifier],
         outputCommitment: [tx.outputs[0].commitment, tx.outputs[1].commitment],
         extAmount: amount,
@@ -114,10 +139,13 @@ async function main() {
         // data for 2 transaction outputs
         outAmount: [tx.outputs[0].amount, tx.outputs[1].amount],
         outBlinding: [tx.outputs[0].blinding, tx.outputs[1].blinding],
-        outPathIndices: merklePathIndicesToBigint(tx.outputs[0].merklePathIndices.slice(0, -1)),
-        outPathElements: tx.outputs[0].merklePathElements.slice(0, -1)
+        outPubkey: [tx.outputs[0].pubkey, tx.outputs[1].pubkey],
+        outPathIndices: merklePathIndicesToBigint(tx.outputs[0].merklePathIndices.slice(1)),
+        outPathElements: tx.outputs[0].merklePathElements.slice(1)
     }
 
+    console.log('input', JSON.stringify(stringifyBigInts(input)))
+
     console.log('Generating SNARK proof...')
     const proofData = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
     const { proof } = websnarkUtils.toSolidityInput(proofData)
@@ -125,17 +153,17 @@ async function main() {
     const args = [
         toHex(input.root),
         toHex(input.newRoot),
-        [toHex(input.inputs[0].nullifier), toHex(input.inputs[1].nullifier)],
-        [toHex(input.inputs[0].commitment), toHex(input.inputs[1].commitment)],
-        toHex(input.amount),
+        [toHex(tx.inputs[0].nullifier), toHex(tx.inputs[1].nullifier)],
+        [toHex(tx.outputs[0].commitment), toHex(tx.outputs[1].commitment)],
+        toHex(amount),
         toHex(input.fee),
         toHex(input.recipient, 20),
         toHex(input.relayer, 20),
     ]
 
-    console.log('Sending withdrawal transaction...')
-    const receipt = await contract.methods.transaction(proof, ...args).send({ valued: amount, from: web3.eth.defaultAccount, gas: 1e6 })
-    console.log(`https://kovan.etherscan.io/tx/${receipt.transactionHash}`)
+    console.log('Sending deposit transaction...')
+    const receipt = await contract.methods.transaction(proof, ...args).send({ value: amount, from: web3.eth.defaultAccount, gas: 1e6 })
+    console.log(`Receipt ${receipt.transactionHash}`)
 
 }