feat(identity-proof): add identity-proof circuit/package

.eslintignore

@@ -21,3 +21,6 @@ build
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+
+# types
+types

.github/workflows/production.yml

@@ -39,6 +39,16 @@ jobs:
                   node-version: 20
                   cache: yarn
 
+            # https://github.com/iden3/circuits/blob/8fffb6609ecad0b7bcda19bb908bdb544bdb3cf7/.github/workflows/main.yml#L18-L22
+            # https://stackoverflow.com/a/78377916
+            - name: Setup Circom deps
+              run: |
+                  sudo rm /etc/apt/sources.list.d/microsoft-prod.list
+                  sudo apt-get update && sudo apt-get install -y wget nlohmann-json3-dev libgmp-dev nasm g++ build-essential
+
+            - name: Setup Circom
+              run: wget https://github.com/iden3/circom/releases/latest/download/circom-linux-amd64 && sudo mv ./circom-linux-amd64 /usr/bin/circom && sudo chmod +x /usr/bin/circom
+
             - name: Install dependencies
               run: yarn
 
@@ -48,20 +58,10 @@ jobs:
             - name: Test libraries
               run: yarn test:libraries
 
-            - name: Coveralls
-              uses: coverallsapp/github-action@v2.2.3
-              with:
-                  github-token: ${{ secrets.GITHUB_TOKEN }}
-                  flag-name: run-libraries
-                  parallel: true
-
-    coverage:
-        runs-on: ubuntu-latest
-        needs: test
+            - name: Test circuits
+              run: yarn test:circuits
 
-        steps:
-            - name: Coveralls Finished
+            - name: Coveralls
               uses: coverallsapp/github-action@v2.2.3
               with:
                   github-token: ${{ secrets.GITHUB_TOKEN }}
-                  parallel-finished: true

.github/workflows/pull-requests.yml

@@ -37,6 +37,16 @@ jobs:
                   node-version: 20
                   cache: yarn
 
+            # https://github.com/iden3/circuits/blob/8fffb6609ecad0b7bcda19bb908bdb544bdb3cf7/.github/workflows/main.yml#L18-L22
+            # https://stackoverflow.com/a/78377916
+            - name: Setup Circom deps
+              run: |
+                  sudo rm /etc/apt/sources.list.d/microsoft-prod.list
+                  sudo apt-get update && sudo apt-get install -y wget nlohmann-json3-dev libgmp-dev nasm g++ build-essential
+
+            - name: Setup Circom
+              run: wget https://github.com/iden3/circom/releases/latest/download/circom-linux-amd64 && sudo mv ./circom-linux-amd64 /usr/bin/circom && sudo chmod +x /usr/bin/circom
+
             - name: Install dependencies
               run: yarn
 
@@ -45,3 +55,6 @@ jobs:
 
             - name: Test libraries
               run: yarn test
+
+            - name: Test circuits
+              run: yarn test:circuits

.prettierrc.json

@@ -1,5 +1,6 @@
 {
     "semi": false,
     "arrowParens": "always",
-    "trailingComma": "none"
+    "trailingComma": "none",
+    "plugins": ["prettier-plugin-solidity"]
 }

README.md

@@ -85,6 +85,25 @@
                 </a>
             </td>
         </tr>
+        <tr>
+            <td>
+                <a href="https://github.com/semaphore-protocol/extensions/tree/main/packages/identity-proof.circom">
+                    @semaphore-extensions/identity-proof.circom
+                </a>
+            </td>
+            <td>
+                <!-- NPM version -->
+                <a href="https://www.npmjs.com/package/@semaphore-extensions/identity-proof.circom">
+                    <img alt="NPM Version" src="https://img.shields.io/npm/v/%40semaphore-extensions%2Fidentity-proof.circom">
+                </a>
+            </td>
+            <td>
+                <!-- Downloads -->
+                <a href="https://npmjs.org/package/@semaphore-extensions/identity-proof.circom">
+                    <img alt="NPM Downloads" src="https://img.shields.io/npm/dm/%40semaphore-extensions%2Fidentity-proof.circom">
+                </a>
+            </td>
+        </tr>
     <tbody>
 </table>
 

jest.config.ts

@@ -1,7 +1,7 @@
 import fs from "fs"
 import type { Config } from "jest"
 
-const exclude = ["circuits", "contracts"]
+const exclude = ["identity-proof.circom"]
 
 const projects: any = fs
     .readdirSync("./packages", { withFileTypes: true })
@@ -21,7 +21,7 @@ const projects: any = fs
 const config: Config = {
     projects,
     verbose: true,
-    coverageDirectory: "./coverage/libraries",
+    coverageDirectory: "./coverage",
     coverageThreshold: {
         global: {
             branches: 90,

package.json

@@ -5,9 +5,10 @@
     "scripts": {
         "build": "yarn build:libraries",
         "build:libraries": "yarn workspaces foreach -A -t --no-private run build",
-        "test": "yarn test:libraries",
+        "test": "yarn test:libraries && yarn test:circuits",
         "test:libraries": "jest --coverage",
         "test:library": "jest packages/${0}",
+        "test:circuits": "yarn workspace @semaphore-extensions/identity-proof.circom test",
         "lint:eslint": "eslint . --ext .js,.ts,.tsx",
         "lint": "yarn lint:eslint",
         "lint:fix": "yarn lint:eslint --fix",
@@ -35,6 +36,7 @@
         "@commitlint/config-conventional": "^19.1.0",
         "@types/jest": "^29.5.12",
         "@types/node": "^20.12.4",
+        "@types/snarkjs": "^0",
         "@typescript-eslint/eslint-plugin": "^7.5.0",
         "@typescript-eslint/parser": "^7.5.0",
         "changelogithub": "patch:changelogithub@npm%3A0.13.5#~/.yarn/patches/changelogithub-npm-0.13.5-9884734389.patch",
@@ -52,7 +54,9 @@
         "jest": "^29.7.0",
         "lint-staged": "^15.2.2",
         "prettier": "^3.2.5",
+        "prettier-plugin-solidity": "^1.3.1",
         "rimraf": "^5.0.5",
+        "snarkjs": "^0.7.4",
         "ts-jest": "^29.1.2",
         "ts-node": "^10.9.2",
         "typedoc": "^0.25.13",

packages/identity-proof.circom/.gitignore

@@ -0,0 +1,3 @@
+ptau
+main
+test

packages/identity-proof.circom/.mocharc.json

@@ -0,0 +1,7 @@
+{
+    "extension": ["ts"],
+    "require": "ts-node/register",
+    "spec": "./tests/*.test.ts",
+    "timeout": 100000,
+    "exit": true
+}

packages/identity-proof.circom/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Ethereum Foundation
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/identity-proof.circom/README.md

@@ -0,0 +1,58 @@
+<p align="center">
+    <h1 align="center">
+        Semaphore Identity Proof (circuit)
+    </h1>
+    <p align="center">A circuit to prove the ownership of a Semaphore identity without revealing the private key.</p>
+</p>
+
+<p align="center">
+    <a href="https://github.com/semaphore-protocol">
+        <img src="https://img.shields.io/badge/project-Semaphore-blue.svg?style=flat-square">
+    </a>
+    <a href="https://github.com/semaphore-protocol/extensions/tree/main/packages/identity-proof.circom/LICENSE">
+        <img alt="NPM license" src="https://img.shields.io/npm/l/%40semaphore-extensions%2Fidentity-proof.circom?style=flat-square">
+    </a>
+    <a href="https://www.npmjs.com/package/@semaphore-extensions/identity-proof.circom">
+        <img alt="NPM version" src="https://img.shields.io/npm/v/@semaphore-extensions/identity-proof.circom?style=flat-square" />
+    </a>
+    <a href="https://npmjs.org/package/@semaphore-extensions/identity-proof.circom">
+        <img alt="Downloads" src="https://img.shields.io/npm/dm/@semaphore-extensions/identity-proof.circom.svg?style=flat-square" />
+    </a>
+</p>
+
+<div align="center">
+    <h4>
+        <a href="https://github.com/semaphore-protocol/extensions/blob/main/CONTRIBUTING.md">
+            👥 Contributing
+        </a>
+        <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
+        <a href="https://github.com/semaphore-protocol/extensions/blob/main/CODE_OF_CONDUCT.md">
+            🤝 Code of conduct
+        </a>
+        <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
+        <a href="https://github.com/semaphore-protocol/extensions/contribute">
+            🔎 Issues
+        </a>
+        <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
+        <a href="https://semaphore.pse.dev/discord">
+            🗣️ Chat &amp; Support
+        </a>
+    </h4>
+</div>
+
+> [!WARNING]  
+> This library has **not** been audited.
+
+## 🛠 Install
+
+Install the `@semaphore-extensions/identity-proof.circom` package with npm:
+
+```bash
+npm i @semaphore-extensions/identity-proof.circom --save
+```
+
+or yarn:
+
+```bash
+yarn add @semaphore-extensions/identity-proof.circom
+```

packages/identity-proof.circom/circomkit.json

@@ -0,0 +1,17 @@
+{
+    "protocol": "groth16",
+    "prime": "bn128",
+    "version": "2.1.5",
+    "circuits": "./circuits.json",
+    "dirPtau": "./ptau",
+    "dirCircuits": "./src",
+    "dirInputs": "./inputs",
+    "dirBuild": "./build",
+    "optimization": 2,
+    "inspect": true,
+    "include": ["../../node_modules/circomlib/circuits"],
+    "groth16numContributions": 1,
+    "groth16askForEntropy": false,
+    "logLevel": "INFO",
+    "verbose": true
+}

packages/identity-proof.circom/circuits.json

@@ -0,0 +1,7 @@
+{
+    "identity-proof": {
+        "file": "identity-proof",
+        "template": "IdentityProof",
+        "pubs": ["scope"]
+    }
+}

packages/identity-proof.circom/package.json

@@ -0,0 +1,36 @@
+{
+    "name": "@semaphore-extensions/identity-proof.circom",
+    "version": "1.0.0-beta",
+    "description": "A circuit to prove the ownership of a Semaphore identity without revealing the private key.",
+    "license": "MIT",
+    "files": [
+        "**/*.circom",
+        "!main",
+        "!test",
+        "LICENSE",
+        "README.md"
+    ],
+    "repository": "https://github.com/semaphore-protocol/extensions",
+    "homepage": "https://github.com/semaphore-protocol/extensions/tree/main/packages/identity-proof.circom",
+    "bugs": {
+        "url": "https://github.com/semaphore-protocol/extensions.git/issues"
+    },
+    "scripts": {
+        "compile": "circomkit compile identity-proof",
+        "setup": "circomkit setup identity-proof",
+        "test": "mocha"
+    },
+    "publishConfig": {
+        "access": "public"
+    },
+    "dependencies": {
+        "circomlib": "2.0.5"
+    },
+    "devDependencies": {
+        "@types/mocha": "^10.0.6",
+        "@zk-kit/eddsa-poseidon": "^1.0.0-beta",
+        "circomkit": "^0.0.19",
+        "mocha": "^10.2.0",
+        "poseidon-lite": "^0.2.0"
+    }
+}

packages/identity-proof.circom/src/identity-proof.circom

@@ -0,0 +1,37 @@
+pragma circom 2.1.5;
+
+include "babyjub.circom";
+include "poseidon.circom";
+include "comparators.circom";
+
+// This circuit can be used to prove the possession of a Semaphore private key
+// without revealing the private key itself. It utilizes
+// the {@link https://eips.ethereum.org/EIPS/eip-2494|Baby Jubjub} elliptic curve, the Poseidon hash function which a highly efficient
+// and secure hash function suited for zero-knowledge proof contexts.
+// A scope value can be used to define a nullifier to prevent the same
+// proof from being re-used twice.
+template IdentityProof() {
+    // The circuit takes two inputs: the private key and an additional scope parameter.
+    signal input secret;
+    signal input scope;
+
+    signal output commitment;
+
+    // The secret scalar must be in the prime subgroup order 'l'.
+    var l = 2736030358979909402780800718157159386076813972158567259200215660948447373041;
+
+    component isLessThan = LessThan(251);
+    isLessThan.in <== [secret, l];
+    isLessThan.out === 1;
+
+    var Ax, Ay;
+
+    // Get the two Baby Jubjub points using the private key.
+    (Ax, Ay) = BabyPbk()(secret);
+
+    // It applies the Poseidon hash function to the to Baby Jubjub points to produce the commitment.
+    commitment <== Poseidon(2)([Ax, Ay]);
+
+    // Dummy constraint to prevent compiler from optimizing it.
+    signal dummySquare <== scope * scope;
+}

packages/identity-proof.circom/tests/common.ts

@@ -0,0 +1,11 @@
+import { Circomkit } from "circomkit"
+import { readFileSync } from "fs"
+import path from "path"
+
+const configFilePath = path.join(__dirname, "../circomkit.json")
+const config = JSON.parse(readFileSync(configFilePath, "utf-8"))
+
+export const circomkit = new Circomkit({
+    ...config,
+    verbose: false
+})

packages/identity-proof.circom/tests/identity-proof.test.ts

@@ -0,0 +1,36 @@
+import { WitnessTester } from "circomkit"
+import { poseidon2 } from "poseidon-lite"
+import { deriveSecretScalar, derivePublicKey } from "@zk-kit/eddsa-poseidon"
+import { circomkit } from "./common"
+
+describe("identity-proof", () => {
+    let circuit: WitnessTester<["secret", "scope"], ["commitment"]>
+
+    const privateKey = Buffer.from("secret")
+    const scope = 2
+
+    const publicKey = derivePublicKey(privateKey)
+    const commitment = poseidon2(publicKey)
+
+    const INPUT = {
+        secret: deriveSecretScalar(privateKey),
+        scope
+    }
+
+    const OUTPUT = {
+        commitment
+    }
+
+    before(async () => {
+        circuit = await circomkit.WitnessTester("identity-proof", {
+            file: "identity-proof",
+            template: "IdentityProof",
+            pubs: ["scope"]
+        })
+    })
+
+    // eslint-disable-next-line jest/expect-expect
+    it("Should compute the commitment correctly", async () => {
+        await circuit.expectPass(INPUT, OUTPUT)
+    })
+})