more tests for snark verification WIP

This commit is contained in:
Alexey 2019-07-15 20:21:58 +03:00
parent 44719acdf0
commit 666aba582c
4 changed files with 111 additions and 65 deletions

4
package-lock.json generated
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@ -8537,8 +8537,8 @@
}
},
"websnark": {
"version": "git+https://github.com/poma/websnark.git#59078413786500a78fdc3cc2c74f834fc759049d",
"from": "git+https://github.com/poma/websnark.git#59078413786500a78fdc3cc2c74f834fc759049d",
"version": "git+https://github.com/poma/websnark.git#271c74a76f4d9277c049283c45929fb3a5bb46fc",
"from": "git+https://github.com/poma/websnark.git#271c74a76f4d9277c049283c45929fb3a5bb46fc",
"requires": {
"big-integer": "^1.6.42"
}

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@ -32,6 +32,6 @@
"truffle-hdwallet-provider": "^1.0.14",
"web3": "^1.0.0-beta.55",
"web3-utils": "^1.0.0-beta.55",
"websnark": "git+https://github.com/poma/websnark.git#59078413786500a78fdc3cc2c74f834fc759049d"
"websnark": "git+https://github.com/poma/websnark.git#271c74a76f4d9277c049283c45929fb3a5bb46fc"
}
}

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@ -1,61 +0,0 @@
const assert = require('assert');
const snarkjs = require("snarkjs");
const bigInt = snarkjs.bigInt;
const utils = require("./utils");
const merkleTree = require('../lib/MerkleTree');
function generateDeposit() {
let deposit = {
secret: utils.rbigint(31),
nullifier: utils.rbigint(31),
};
const preimage = Buffer.concat([deposit.nullifier.leInt2Buff(32), deposit.secret.leInt2Buff(32)]);
deposit.commitment = utils.pedersenHash(preimage);
return deposit;
}
(async () => {
// === Create 3 deposits ===
const dep1 = generateDeposit();
const dep2 = generateDeposit();
const dep3 = generateDeposit();
const tree = new merkleTree(16);
await tree.insert(dep1.commitment);
await tree.insert(dep2.commitment);
await tree.insert(dep3.commitment);
// === Withdrawing deposit 2 ===
const {root, path_elements, path_index} = await tree.path(1);
// Circuit input
const input = {
// public
root: root,
nullifier: dep2.nullifier,
receiver: utils.rbigint(20),
fee: bigInt(1e17),
// private
secret: dep2.secret,
pathElements: path_elements,
pathIndex: path_index,
};
console.log("Input:\n", input);
console.time("Time");
const proof = await utils.snarkProof(input);
console.log("Proof:\n", proof);
console.timeEnd("Time");
const verify = await utils.snarkVerify(proof);
assert(verify);
// try to cheat with recipient
proof.publicSignals[2] = '0x000000000000000000000000000000000000000000000000000000000000beef';
const verifyScam = await utils.snarkVerify(proof);
assert(!verifyScam);
console.log("Done.");
})();

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@ -2,6 +2,7 @@ const should = require('chai')
.use(require('bn-chai')(web3.utils.BN))
.use(require('chai-as-promised'))
.should()
const fs = require('fs')
const { toWei, toBN, fromWei, toHex, randomHex } = require('web3-utils')
const { takeSnapshot, revertSnapshot, increaseTime } = require('../scripts/ganacheHelper');
@ -10,6 +11,8 @@ const Mixer = artifacts.require('./Mixer.sol')
const { AMOUNT } = process.env
const utils = require('../scripts/utils')
const websnarkUtils = require('websnark/src/utils')
const buildGroth16 = require('websnark/src/groth16');
const stringifyBigInts = require('websnark/tools/stringifybigint').stringifyBigInts
const snarkjs = require('snarkjs');
const bigInt = snarkjs.bigInt;
@ -33,6 +36,14 @@ function BNArrayToStringArray(array) {
return arrayToPrint
}
function getRandomReceiver() {
let receiver = utils.rbigint(20)
while (toHex(receiver.toString()).length !== 42) {
receiver = utils.rbigint(20)
}
return receiver
}
contract('Mixer', async accounts => {
let mixer
const sender = accounts[0]
@ -43,8 +54,11 @@ contract('Mixer', async accounts => {
let prefix = 'test'
let tree
const fee = bigInt(1e17)
const receiver = utils.rbigint(20)
const receiver = getRandomReceiver()
const relayer = accounts[1]
let groth16
let circuit
let proving_key
before(async () => {
tree = new MerkleTree(
@ -55,6 +69,9 @@ contract('Mixer', async accounts => {
)
mixer = await Mixer.deployed()
snapshotId = await takeSnapshot()
groth16 = await buildGroth16()
circuit = require("../build/circuits/withdraw.json")
proving_key = fs.readFileSync("build/circuits/withdraw_proving_key.bin").buffer
})
describe('#constructor', async () => {
@ -85,6 +102,47 @@ contract('Mixer', async accounts => {
})
})
describe('snark proof verification on js side', async () => {
it('should detect tampering', async () => {
const deposit = generateDeposit()
await tree.insert(deposit.commitment)
const { root, path_elements, path_index } = await tree.path(0);
const input = stringifyBigInts({
root,
nullifier: deposit.nullifier,
receiver,
fee,
secret: deposit.secret,
pathElements: path_elements,
pathIndex: path_index,
})
let proof = await websnarkUtils.genWitnessAndProve(groth16, input, circuit, proving_key)
const originalProof = JSON.parse(JSON.stringify(proof))
let result = await utils.snarkVerify(proof)
result.should.be.equal(true)
// nullifier
proof.publicSignals[1] = '133792158246920651341275668520530514036799294649489851421007411546007850802'
result = await utils.snarkVerify(proof)
result.should.be.equal(false)
proof = originalProof
// try to cheat with recipient
proof.publicSignals[2] = '133738360804642228759657445999390850076318544422'
result = await utils.snarkVerify(proof)
result.should.be.equal(false)
proof = originalProof
// fee
proof.publicSignals[3] = '1337100000000000000000'
result = await utils.snarkVerify(proof)
result.should.be.equal(false)
proof = originalProof
})
})
describe('#withdraw', async () => {
it('should work', async () => {
const deposit = generateDeposit()
@ -204,6 +262,55 @@ contract('Mixer', async accounts => {
const error = await mixer.withdraw(pi_a, pi_b, pi_c, publicSignals, { from: relayer }).should.be.rejected
error.reason.should.be.equal('Cannot find your merkle root')
})
it('should reject with tampered public inputs', async () => {
const deposit = generateDeposit()
await tree.insert(deposit.commitment)
await mixer.deposit(toBN(deposit.commitment.toString()), { value: AMOUNT, from: sender })
let {root, path_elements, path_index} = await tree.path(0)
const userInput = stringifyBigInts({
root,
nullifier: deposit.nullifier,
receiver,
fee,
secret: deposit.secret,
pathElements: path_elements,
pathIndex: path_index,
})
let { pi_a, pi_b, pi_c, publicSignals } = await utils.snarkProof(userInput)
const originalPublicSignals = publicSignals.slice()
const originalPi_a = pi_a.slice()
// receiver
publicSignals[2] = '0x0000000000000000000000007a1f9131357404ef86d7c38dbffed2da70321337'
let error = await mixer.withdraw(pi_a, pi_b, pi_c, publicSignals, { from: relayer }).should.be.rejected
error.reason.should.be.equal('Invalid withdraw proof');
// fee
publicSignals = originalPublicSignals.slice()
publicSignals[3] = '0x000000000000000000000000000000000000000000000000015345785d8a0000'
error = await mixer.withdraw(pi_a, pi_b, pi_c, publicSignals, { from: relayer }).should.be.rejected
error.reason.should.be.equal('Invalid withdraw proof');
// nullifier
publicSignals = originalPublicSignals.slice()
publicSignals[1] = '0x00abdfc78211f8807b9c6504a6e537e71b8788b2f529a95f1399ce124a8642ad'
error = await mixer.withdraw(pi_a, pi_b, pi_c, publicSignals, { from: relayer }).should.be.rejected
error.reason.should.be.equal('Invalid withdraw proof');
// proof itself
pi_a[0] = '0x261d81d8203437f29b38a88c4263476d858e6d9645cf21740461684412b31337'
await mixer.withdraw(pi_a, pi_b, pi_c, originalPublicSignals, { from: relayer }).should.be.rejected
// should work with original values
await mixer.withdraw(originalPi_a, pi_b, pi_c, originalPublicSignals, { from: relayer }).should.be.fulfilled
})
})
afterEach(async () => {