feat: track roots in rln contract and use sepolia instead of goerli (#62)

.cspell.json

@@ -9,6 +9,7 @@
     "merkle",
     "nwaku",
     "rlnjs",
+    "sepolia",
     "vkey",
     "Waku",
     "zerokit",

example/index.js

@@ -1,58 +1,64 @@
 import * as rln from "@waku/rln";
 
-rln.create().then(async rlnInstance => {
-    const credentials = rlnInstance.generateIdentityCredentials();
+rln.create().then(async (rlnInstance) => {
+  const credentials = rlnInstance.generateIdentityCredentials();
 
-    //peer's index in the Merkle Tree
-    const index = 5
+  //peer's index in the Merkle Tree
+  const index = 5;
 
-    // Create a Merkle tree with random members
-    for (let i = 0; i < 10; i++) {
-        if (i == index) {
-            // insert the current peer's pk
-            rlnInstance.insertMember(credentials.IDCommitment);
-        } else {
-            // create a new key pair
-            const credentials = rlnInstance.generateIdentityCredentials(); // TODO: handle error
-            rlnInstance.insertMember(credentials.IDCommitment);
-
-        }
+  // Create a Merkle tree with random members
+  for (let i = 0; i < 10; i++) {
+    if (i == index) {
+      // insert the current peer's pk
+      rlnInstance.insertMember(credentials.IDCommitment);
+    } else {
+      // create a new key pair
+      const credentials = rlnInstance.generateIdentityCredentials(); // TODO: handle error
+      rlnInstance.insertMember(credentials.IDCommitment);
     }
+  }
 
-    // prepare the message
-    const uint8Msg = Uint8Array.from("Hello World".split("").map(x => x.charCodeAt()));
+  // prepare the message
+  const uint8Msg = Uint8Array.from(
+    "Hello World".split("").map((x) => x.charCodeAt())
+  );
 
-    // setting up the epoch
-    const epoch = new Date();
+  // setting up the epoch
+  const epoch = new Date();
 
-    console.log("Generating proof...");
-    console.time("proof_gen_timer");
-    let proof = await rlnInstance.generateRLNProof(uint8Msg, index, epoch, credentials.IDSecretHash)
-    console.timeEnd("proof_gen_timer");
-    console.log("Proof", proof)
+  console.log("Generating proof...");
+  console.time("proof_gen_timer");
+  let proof = await rlnInstance.generateRLNProof(
+    uint8Msg,
+    index,
+    epoch,
+    credentials.IDSecretHash
+  );
+  console.timeEnd("proof_gen_timer");
+  console.log("Proof", proof);
 
-    try {
-        // verify the proof
-        let verifResult = rlnInstance.verifyRLNProof(proof, uint8Msg);
-        console.log("Is proof verified?", verifResult ? "yes" : "no");
-    } catch (err) {
-        console.log("Invalid proof")
-    }
+  try {
+    // verify the proof
+    let verifResult = rlnInstance.verifyRLNProof(proof, uint8Msg);
+    console.log("Is proof verified?", verifResult ? "yes" : "no");
+  } catch (err) {
+    console.log("Invalid proof");
+  }
 
-    const provider = new ethers.providers.Web3Provider(
-        window.ethereum,
-        "any"
-    );
+  const provider = new ethers.providers.Web3Provider(window.ethereum, "any");
 
-    const DEFAULT_SIGNATURE_MESSAGE =
-        "The signature of this message will be used to generate your RLN credentials. Anyone accessing it may send messages on your behalf, please only share with the RLN dApp";  
+  const DEFAULT_SIGNATURE_MESSAGE =
+    "The signature of this message will be used to generate your RLN credentials. Anyone accessing it may send messages on your behalf, please only share with the RLN dApp";
 
-    const signer = provider.getSigner();
-    const signature = await signer.signMessage(DEFAULT_SIGNATURE_MESSAGE);
-    console.log(`Got signature: ${signature}`);
+  const signer = provider.getSigner();
+  const signature = await signer.signMessage(DEFAULT_SIGNATURE_MESSAGE);
+  console.log(`Got signature: ${signature}`);
 
-    const contract = await rln.RLNContract.init(rlnInstance, {address: rln.GOERLI_CONTRACT.address, provider: signer });
+  const contract = await rln.RLNContract.init(rlnInstance, {
+    address: rln.SEPOLIA_CONTRACT.address,
+    provider: signer,
+  });
 
-    const event = await contract.registerMember(rlnInstance, signature);
-    console.log(`Registered as member with ${event}`);
+  const event = await contract.registerMember(rlnInstance, signature);
+  console.log(`Registered as member with ${event}`);
 });

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@waku/rln",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@waku/rln",
-      "version": "0.1.0",
+      "version": "0.1.1",
       "license": "MIT OR Apache-2.0",
       "dependencies": {
         "@waku/utils": "^0.0.5",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@waku/rln",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "Rate Limit Nullifier for js-waku",
   "types": "./dist/index.d.ts",
   "module": "./dist/index.js",

src/codec.spec.ts

@@ -63,7 +63,7 @@ describe("RLN codec with version 0", () => {
     ))!;
 
     expect(msg.rateLimitProof).to.not.be.undefined;
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -104,7 +104,7 @@ describe("RLN codec with version 0", () => {
     expect(msg).to.not.be.undefined;
     expect(msg.rateLimitProof).to.not.be.undefined;
 
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -153,7 +153,7 @@ describe("RLN codec with version 1", () => {
     ))!;
 
     expect(msg.rateLimitProof).to.not.be.undefined;
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -199,7 +199,7 @@ describe("RLN codec with version 1", () => {
     expect(msg).to.not.be.undefined;
     expect(msg.rateLimitProof).to.not.be.undefined;
 
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -247,7 +247,7 @@ describe("RLN codec with version 1", () => {
     ))!;
 
     expect(msg.rateLimitProof).to.not.be.undefined;
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -294,7 +294,7 @@ describe("RLN codec with version 1", () => {
     expect(msg).to.not.be.undefined;
     expect(msg.rateLimitProof).to.not.be.undefined;
 
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch).to.be.gt(0);
@@ -340,7 +340,7 @@ describe("RLN Codec - epoch", () => {
     expect(msg).to.not.be.undefined;
     expect(msg.rateLimitProof).to.not.be.undefined;
 
-    expect(msg.verify()).to.be.true;
+    expect(msg.verify([rlnInstance.getMerkleRoot()])).to.be.true;
     expect(msg.verifyNoRoot()).to.be.true;
     expect(msg.epoch).to.not.be.undefined;
     expect(msg.epoch!.toString(10).length).to.eq(9);

src/constants.ts

@@ -6,9 +6,9 @@ export const RLN_ABI = [
   "event MemberWithdrawn(uint256 pubkey, uint256 index)",
 ];
 
-export const GOERLI_CONTRACT = {
-  chainId: 5,
-  startBlock: 7109391,
-  address: "0x4252105670fe33d2947e8ead304969849e64f2a6",
+export const SEPOLIA_CONTRACT = {
+  chainId: 11155111,
+  startBlock: 3193048,
+  address: "0x9C09146844C1326c2dBC41c451766C7138F88155",
   abi: RLN_ABI,
 };

src/index.ts

@@ -1,5 +1,5 @@
 import { RLNDecoder, RLNEncoder } from "./codec.js";
-import { GOERLI_CONTRACT, RLN_ABI } from "./constants.js";
+import { RLN_ABI, SEPOLIA_CONTRACT } from "./constants.js";
 import {
   IdentityCredential,
   Proof,
@@ -28,5 +28,5 @@ export {
   MerkleRootTracker,
   RLNContract,
   RLN_ABI,
-  GOERLI_CONTRACT,
+  SEPOLIA_CONTRACT,
 };

src/message.ts

@@ -22,11 +22,12 @@ export class RlnMessage<T extends IDecodedMessage> implements IDecodedMessage {
     public rateLimitProof: IRateLimitProof | undefined
   ) {}
 
-  public verify(): boolean | undefined {
+  public verify(roots: Uint8Array[]): boolean | undefined {
     return this.rateLimitProof
       ? this.rlnInstance.verifyWithRoots(
           this.rateLimitProof,
-          toRLNSignal(this.msg.contentTopic, this.msg)
+          toRLNSignal(this.msg.contentTopic, this.msg),
+          ...roots
         ) // this.rlnInstance.verifyRLNProof once issue status-im/nwaku#1248 is fixed
       : undefined;
   }

src/rln_contract.spec.ts

@@ -13,9 +13,9 @@ describe("RLN Contract abstraction", () => {
     rlnInstance.insertMember = () => undefined;
     const insertMemberSpy = chai.spy.on(rlnInstance, "insertMember");
 
-    const voidSigner = new ethers.VoidSigner(rln.GOERLI_CONTRACT.address);
-    const rlnContract = new rln.RLNContract({
-      address: rln.GOERLI_CONTRACT.address,
+    const voidSigner = new ethers.VoidSigner(rln.SEPOLIA_CONTRACT.address);
+    const rlnContract = new rln.RLNContract(rlnInstance, {
+      address: rln.SEPOLIA_CONTRACT.address,
       provider: voidSigner,
     });
 
@@ -33,9 +33,9 @@ describe("RLN Contract abstraction", () => {
       "0xdeb8a6b00a8e404deb1f52d3aa72ed7f60a2ff4484c737eedaef18a0aacb2dfb4d5d74ac39bb71fa358cf2eb390565a35b026cc6272f2010d4351e17670311c21c";
 
     const rlnInstance = await rln.create();
-    const voidSigner = new ethers.VoidSigner(rln.GOERLI_CONTRACT.address);
-    const rlnContract = new rln.RLNContract({
-      address: rln.GOERLI_CONTRACT.address,
+    const voidSigner = new ethers.VoidSigner(rln.SEPOLIA_CONTRACT.address);
+    const rlnContract = new rln.RLNContract(rlnInstance, {
+      address: rln.SEPOLIA_CONTRACT.address,
       provider: voidSigner,
     });
 

src/rln_contract.ts

@@ -2,6 +2,7 @@ import { ethers } from "ethers";
 
 import { RLN_ABI } from "./constants.js";
 import { IdentityCredential, RLNInstance } from "./rln.js";
+import { MerkleRootTracker } from "./root_tracker";
 
 type Member = {
   pubkey: string;
@@ -22,6 +23,7 @@ type FetchMembersOptions = {
 export class RLNContract {
   private _contract: ethers.Contract;
   private membersFilter: ethers.EventFilter;
+  private merkleRootTracker: MerkleRootTracker;
 
   private _members: Member[] = [];
 
@@ -29,7 +31,7 @@ export class RLNContract {
     rlnInstance: RLNInstance,
     options: ContractOptions
   ): Promise<RLNContract> {
-    const rlnContract = new RLNContract(options);
+    const rlnContract = new RLNContract(rlnInstance, options);
 
     await rlnContract.fetchMembers(rlnInstance);
     rlnContract.subscribeToMembers(rlnInstance);
@@ -37,8 +39,14 @@ export class RLNContract {
     return rlnContract;
   }
 
-  constructor({ address, provider }: ContractOptions) {
+  constructor(
+    rlnInstance: RLNInstance,
+    { address, provider }: ContractOptions
+  ) {
+    const initialRoot = rlnInstance.getMerkleRoot();
+
     this._contract = new ethers.Contract(address, RLN_ABI, provider);
+    this.merkleRootTracker = new MerkleRootTracker(5, initialRoot);
     this.membersFilter = this.contract.filters.MemberRegistered();
   }
 
@@ -58,38 +66,91 @@ export class RLNContract {
       ...options,
       membersFilter: this.membersFilter,
     });
+    this.processEvents(rlnInstance, registeredMemberEvents);
+  }
 
-    for (const event of registeredMemberEvents) {
-      this.addMemberFromEvent(rlnInstance, event);
-    }
+  public processEvents(rlnInstance: RLNInstance, events: ethers.Event[]): void {
+    const toRemoveTable = new Map<number, number[]>();
+    const toInsertTable = new Map<number, ethers.Event[]>();
+
+    events.forEach((evt) => {
+      if (!evt.args) {
+        return;
+      }
+
+      if (evt.removed) {
+        const index: number = evt.args.index;
+        const toRemoveVal = toRemoveTable.get(evt.blockNumber);
+        if (toRemoveVal != undefined) {
+          toRemoveVal.push(index);
+          toRemoveTable.set(evt.blockNumber, toRemoveVal);
+        } else {
+          toRemoveTable.set(evt.blockNumber, [index]);
+        }
+      } else {
+        let eventsPerBlock = toInsertTable.get(evt.blockNumber);
+        if (eventsPerBlock == undefined) {
+          eventsPerBlock = [];
+        }
+
+        eventsPerBlock.push(evt);
+        toInsertTable.set(evt.blockNumber, eventsPerBlock);
+      }
+
+      this.removeMembers(rlnInstance, toRemoveTable);
+      this.insertMembers(rlnInstance, toInsertTable);
+    });
+  }
+
+  private insertMembers(
+    rlnInstance: RLNInstance,
+    toInsert: Map<number, ethers.Event[]>
+  ): void {
+    toInsert.forEach((events: ethers.Event[], blockNumber: number) => {
+      events.forEach((evt) => {
+        if (!evt.args) {
+          return;
+        }
+
+        const pubkey = evt.args.pubkey;
+        const index = evt.args.index;
+        const idCommitment = ethers.utils.zeroPad(
+          ethers.utils.arrayify(pubkey),
+          32
+        );
+        rlnInstance.insertMember(idCommitment);
+        this.members.push({ index, pubkey });
+      });
+
+      const currentRoot = rlnInstance.getMerkleRoot();
+      this.merkleRootTracker.pushRoot(blockNumber, currentRoot);
+    });
+  }
+
+  private removeMembers(
+    rlnInstance: RLNInstance,
+    toRemove: Map<number, number[]>
+  ): void {
+    const removeDescending = new Map([...toRemove].sort().reverse());
+    removeDescending.forEach((indexes: number[], blockNumber: number) => {
+      indexes.forEach((index) => {
+        const idx = this.members.findIndex((m) => m.index === index);
+        if (idx > -1) {
+          this.members.splice(idx, 1);
+        }
+        rlnInstance.deleteMember(index);
+      });
+
+      this.merkleRootTracker.backFill(blockNumber);
+    });
   }
 
   public subscribeToMembers(rlnInstance: RLNInstance): void {
     this.contract.on(this.membersFilter, (_pubkey, _index, event) =>
-      this.addMemberFromEvent(rlnInstance, event)
+      this.processEvents(rlnInstance, event)
     );
   }
 
-  private addMemberFromEvent(
-    rlnInstance: RLNInstance,
-    event: ethers.Event
-  ): void {
-    if (!event.args) {
-      return;
-    }
-
-    const pubkey: string = event.args.pubkey;
-    const index: number = event.args.index;
-
-    this.members.push({ index, pubkey });
-
-    const idCommitment = ethers.utils.zeroPad(
-      ethers.utils.arrayify(pubkey),
-      32
-    );
-    rlnInstance.insertMember(idCommitment);
-  }
-
   public async registerWithSignature(
     rlnInstance: RLNInstance,
     signature: string
@@ -113,6 +174,10 @@ export class RLNContract {
 
     return txRegisterReceipt?.events?.[0];
   }
+
+  public roots(): Uint8Array[] {
+    return this.merkleRootTracker.roots();
+  }
 }
 
 type CustomQueryOptions = FetchMembersOptions & {