hardhat-noir
v0.2.1
Published
Hardhat plugin for Aztec Noir
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hardhat-noir
An unofficial Hardhat plugin for working with circuits written in Noir.
Inspired by vezenovm/basic_mul_noir_example.
What
This plugin adds convenience methods to the Hardhat Runtime Environment for generating and verifying proofs for a circuit.
import { noir } from "hardhat";
it("verifies proof for mul", async function () {
const input = { x: 3, y: 4, result: 12 };
expect(await noir.getCircuit().verifyProofFor(input)).to.be.true;
});
This plugin also hooks to the default compile
task so circuits are automatically compiled whenever you run hardhat compile
Circuits will only be recompiled if there are any changes detected in the source files. The same applies to the Solidity verifier contract, which is generated in Hardhat's configured contracts folder, and the pragma is tweaked to support Solidity 0.8. These tasks can also be manually invoked via noir:compile
and noir:contract
.
$ hardhat compile
Compiling circuit mul with nargo...
ACIR gates generated : 13
Generated ACIR code into build/mul.acir
Ok("/home/spalladino/Projects/hardhat-noir/example/circuits/build/mul.acir")
Generating verifier contract for mul with nargo...
ACIR gates generated : 13
Contract successfully created and located at contract/plonk_vk.sol
Moved verifier contract to MulVerifier.sol in contracts folder
Compiled 1 Solidity file successfully
Done in 2.59s.
Installation
npm install hardhat-noir
Import the plugin in your hardhat.config.js
:
require("hardhat-noir");
Or if you are using TypeScript, in your hardhat.config.ts
:
import "hardhat-noir";
Tasks
These tasks only run if there are no changes detected so circuit source files, or are invoked with the --force
flag. Both tasks will use the WASM libraries, unless the flag --nargo
is set or useNargo
is set to true in the config, in which case they will use the nargo
binary available in the PATH.
noir:compile
: Compiles the circuit in thecircuitsPath
.noir:contract
: Generates a verifier contract for the circuit in Hardhat's contracts folder.
:wink: The solidity pragma of the generated contract is automatically changed from
>=0.6.0 <0.8.0
to>=0.6.0 <0.9.0
to support the latest versions of solc, since the generated verifier is compatible with the 0.8 releases.
Environment extensions
This plugin adds a noir
field to the Hardhat Runtime Environment, which exposes a getCircuit
method. This returns a Circuit
abstraction with the following convenience methods, which are wrappers over the ones in @noir-lang/barretenberg/dest/client_proofs
.
getProof(input)
: Generates a proof for the circuit given the input variables.verifyProof(proof)
: Verifies a proof.verifyProofFor(input)
: Generates and verifies a proof in a single call.
As an example:
import { noir } from "hardhat";
async function run(): Promise<boolean> {
const input = { x: 3, y: 4, result: 12 };
return noir.getCircuit().verifyProofFor(input);
}
The equivalent code without the plugin would be the following, as adapted from the basic_mul_noir_example
:
import { acir_from_bytes } from '@noir-lang/noir_wasm';
import { setup_generic_prover_and_verifier, create_proof, verify_proof } from '@noir-lang/barretenberg/dest/client_proofs';
async function run(): Promise<boolean> {
const acirBuffer = readFileSync('./circuits/build/mul.acir');
const acirByteArray = new Uint8Array(buffer);
const acir = acir_from_bytes(acirByteArray);
const abi = { x: 3, y: 4, result: 12 };
const [prover, verifier] = await setup_generic_prover_and_verifier(acir);
const proof = await create_proof(prover, acir, abi);
return await verify_proof(verifier, proof);
}
Configuration
This plugin extends the Hardhat config with a noir
field with the following fields. See the config.ts
file for more info.
module.exports = {
noir: {
circuitsPath: 'circuits',
mainCircuitName: 'main',
nargoBin: 'nargo',
useNargo: false,
autoCompile: true,
autoGenerateContract: true,
}
};
Next
Ideas for future improvements:
- [ ] Support multiple circuits within the same Hardhat project, each on their individual folder
- [x] Fall back to compilation and verifier generation using node libraries, if nargo is unavailable