feat: create semaphore proofs, test

common/interep-utils.ts

@@ -1,11 +1,17 @@
-import { utils } from "ethers";
+import { Signer, utils } from "ethers";
+import createIdentity from "@interep/identity";
+import { Group, Member } from "@semaphore-protocol/group";
+import { generateProof, packToSolidityProof } from "@semaphore-protocol/proof";
+import type { Identity } from "@semaphore-protocol/identity";
+// import createProof from '@interep/proof'
+import type { SnarkArtifacts } from "@interep/proof/dist/types/types";
 
 export const sToBytes32 = (str: string): string => {
   return utils.formatBytes32String(str);
 };
 
 // zerokit can only use 15, 19, and 20 depth
-export const merkleTreeDepth = 15;
+export const merkleTreeDepth = 20;
 
 export const SNARK_SCALAR_FIELD = BigInt(
   "21888242871839275222246405745257275088548364400416034343698204186575808495617"
@@ -43,3 +49,59 @@ export const getGroups = () => {
 export const getValidGroups = () => {
   return getGroups().filter((group) => group.name !== sToBytes32("bronze"));
 };
+
+export const createInterepIdentity = (signer: Signer, provider: string) => {
+  if (!providers.includes(provider))
+    throw new Error(`Invalid provider: ${provider}`);
+
+  const sign = (message: string) => signer.signMessage(message);
+  return createIdentity(sign, provider);
+};
+
+interface ProofCreationArgs {
+  identity: Identity;
+  members: Member[];
+  groupProvider: typeof providers[0];
+  groupTier: typeof tiers[0];
+  externalNullifier: number;
+  signal: string;
+  snarkArtifacts: SnarkArtifacts;
+}
+
+// Similar to https://github.com/interep-project/interep.js/blob/ae7d19f560a63fef08b71ecba7a926729538011c/packages/proof/src/createProof.ts#L21,
+// but without the api interactions
+// Note: An aribitrary set of members is passed in, without validation
+// when this function is called, ensure that the membership set passed in is a valid representation of onchain membership
+export const createInterepProof = async (args: ProofCreationArgs) => {
+  const group = new Group(merkleTreeDepth);
+
+  const idCommitment = args.identity.getCommitment();
+
+  group.addMembers(args.members);
+
+  const memberIndex = group.indexOf(idCommitment);
+  if (memberIndex === -1) {
+    throw new Error("The semaphore identity is not yet verifiable onchain");
+  }
+
+  const merkleProof = group.generateProofOfMembership(memberIndex);
+
+  const { publicSignals, proof } = await generateProof(
+    args.identity,
+    merkleProof,
+    BigInt(args.externalNullifier),
+    args.signal,
+    args.snarkArtifacts
+  );
+
+  const solidityProof = packToSolidityProof(proof);
+  const groupId = createGroupId(args.groupProvider, args.groupTier).toString();
+
+  return {
+    groupId,
+    signal: args.signal,
+    publicSignals,
+    proof,
+    solidityProof,
+  };
+};

package.json

@@ -20,6 +20,8 @@
     "@nomiclabs/hardhat-etherscan": "^3.1.0",
     "@nomiclabs/hardhat-waffle": "^2.0.3",
     "@semaphore-protocol/contracts": "2.0.0",
+    "@interep/identity": "0.3.0",
+    "@interep/proof": "0.7.0",
     "@types/mocha": "^9.1.1",
     "chai": "^4.3.6",
     "ethereum-waffle": "^3.4.4",

test/rln.ts

@@ -1,7 +1,12 @@
 import { expect, assert } from "chai";
 import { BigNumber } from "ethers";
 import { ethers, deployments } from "hardhat";
-import { createGroupId, sToBytes32 } from "../common";
+import {
+  createGroupId,
+  createInterepIdentity,
+  createInterepProof,
+  sToBytes32,
+} from "../common";
 
 describe("RLN", () => {
   beforeEach(async () => {
@@ -134,6 +139,32 @@ describe("RLN", () => {
     expect(pubkey.toHexString() === dummyPubkey.toHexString());
   });
 
+  it.only("[interep] should generate proof for registration", async () => {
+    const signer = ethers.provider.getSigner(0);
+    const identity = await createInterepIdentity(signer, "github");
+
+    // create a proof to test
+    const proof = await createInterepProof({
+      identity,
+      members: [identity.getCommitment()],
+      groupProvider: "github",
+      groupTier: "silver",
+      signal: "foo",
+      externalNullifier: 1,
+      snarkArtifacts: {
+        wasmFilePath: "./test/snarkArtifacts/semaphore.wasm",
+        zkeyFilePath: "./test/snarkArtifacts/semaphore.zkey",
+      },
+    });
+
+    expect(proof.groupId).to.eql(
+      "19580063316323634959827976785370507245708993886389832860880129572471638471998"
+    );
+    expect(proof.publicSignals.merkleRoot).to.eql(
+      "10738127364751233254031334835017982823925916365031589705155005906674724477907"
+    );
+  });
+
   it("[interep] should withdraw membership", () => {
     // TODO
   });