Add rate limit (#3)

README.md

@@ -1 +1,30 @@
 # cross-chain-contracts-internal
+This repository contains contracts to support cross chain bridging on EVM chains. The main contract is
+[OFTWrapper](contracts/OFTWrapper.sol) which supports bridging using LayerZero.
+
+## OFTWrapper
+This contract is a proxy around LayerZero's OFT standard. The `OFTWrapper` can be called 
+by LayerZero to mint and burn tokens like normal. The `OFTWrapper` then forwards those requests
+to the underlying token. The underlying token must grant this contract permission to mint and burn.
+
+## Upgrade process
+`OFTWrapper` is a non-upgradeable contract. If a change needs to be made a new contract should be deployed.
+The underlying token should then revoke mint and burn permissions on the old contract and grant mint and burn
+permissions to the new contract.
+
+## Contract Tests
+Install dependencies:
+
+`npm install`
+
+Compile the contracts:
+
+`npx hardhat compile`
+
+Run unit tests:
+
+`npx hardhat test`
+
+Check test coverage:
+
+`npx hardhat coverage`

contracts/OFTWrapper.sol

@@ -3,15 +3,17 @@
 pragma solidity ^0.8.20;
 
 import {OFTCore, IOFT} from "@layerzerolabs/lz-evm-oapp-v2/contracts/oft/OFTCore.sol";
+import {RateLimiter} from "@layerzerolabs/oapp-evm/contracts/oapp/utils/RateLimiter.sol";
 import {PaxosTokenV2} from "PaxosToken/contracts/PaxosTokenV2.sol";
 
 /**
  * @title OFTWrapper
  * @dev This contract is a proxy around LayerZero's OFT standard.  The OFTWrapper can be called
  * by LayerZero to mint and burn tokens like normal.  The OFTWrapper then forwards those requests
  * to the underlying token.  The underlying token must grant this contract permission to mint and burn.
+ * @custom:security-contact [email protected]
  */
-contract OFTWrapper is OFTCore {
+contract OFTWrapper is OFTCore, RateLimiter {
     //The Paxos token
     PaxosTokenV2 private immutable paxosToken;
 
@@ -24,9 +26,11 @@ contract OFTWrapper is OFTCore {
     constructor(
         address _paxosToken,
         address _lzEndpoint,
-        address _delegate
+        address _delegate,
+        RateLimitConfig[] memory _rateLimitConfigs
     ) OFTCore(6, _lzEndpoint, _delegate) {
         paxosToken = PaxosTokenV2(_paxosToken);
+        _setRateLimits(_rateLimitConfigs);
     }
 
     /**
@@ -55,6 +59,16 @@ contract OFTWrapper is OFTCore {
         return false;
     }
 
+    /**
+     * @dev Sets the rate limits based on RateLimitConfig array. Only callable by the owner.
+     * @param _rateLimitConfigs An array of RateLimitConfig structures defining the rate limits.
+     */
+    function setRateLimits(
+        RateLimitConfig[] calldata _rateLimitConfigs
+    ) external onlyOwner {
+        _setRateLimits(_rateLimitConfigs);
+    }
+
     /**
      * @dev Internal function to perform a debit operation.  Calls the underlying token
      * to perform the burn via `decreaseSupplyFromAddress`.
@@ -80,6 +94,7 @@ contract OFTWrapper is OFTCore {
             _minAmountLD,
             _dstEid
         );
+        _checkAndUpdateRateLimit(_dstEid, amountSentLD);
         paxosToken.decreaseSupplyFromAddress(amountSentLD, _from);
     }
 

contracts/fixture/OFTWrapperFixture.sol

@@ -10,8 +10,9 @@ contract OFTWrapperFixture is OFTWrapper {
     constructor(
         address _tokenAddress,
         address _lzEndpoint,
-        address _delegate
-    ) OFTWrapper(_tokenAddress, _lzEndpoint, _delegate) {
+        address _delegate,
+        RateLimitConfig[] memory _rateLimitConfigs
+    ) OFTWrapper(_tokenAddress, _lzEndpoint, _delegate, _rateLimitConfigs) {
     }
 
     //Used to test the _debit internal function directly

package.json

@@ -11,6 +11,7 @@
   "license": "MIT",
   "devDependencies": {
     "@layerzerolabs/lz-v2-utilities": "^2.3.42",
+    "@layerzerolabs/oapp-evm": "^0.0.4",
     "@layerzerolabs/oft-evm": "^0.0.8",
     "@layerzerolabs/toolbox-hardhat": "^0.3.7",
     "@nomicfoundation/hardhat-toolbox": "^2.0.2",

scripts/deploy.js

@@ -2,18 +2,25 @@ const { ethers } = require("hardhat");
 const { PrintDeployerDetails, PrintContractDetails } = require('./utils');
 const { ValidateEnvironmentVariables } = require('./utils/helpers');
 
-const { TOKEN_ADDRESS, ETH_ENDPOINT_CONTRACT_ADDRESS, DELEGATE_ADDRESS } = process.env;
+const { TOKEN_ADDRESS, ETH_ENDPOINT_CONTRACT_ADDRESS, DELEGATE_ADDRESS, DESTINATION_EID, LIMIT, WINDOW } = process.env;
 
 const OFT_WRAPPER_CONTRACT_NAME = "OFTWrapper";
 
+const rateLimitConfig = {
+  dstEid: DESTINATION_EID,
+  limit: LIMIT,
+  window: WINDOW
+}
+
 const initializerArgs = [
   TOKEN_ADDRESS,
   ETH_ENDPOINT_CONTRACT_ADDRESS,
   DELEGATE_ADDRESS,
+  [rateLimitConfig]
 ]
 
 async function main() {
-  ValidateEnvironmentVariables(initializerArgs)
+  ValidateEnvironmentVariables(TOKEN_ADDRESS, ETH_ENDPOINT_CONTRACT_ADDRESS, DELEGATE_ADDRESS, DESTINATION_EID, LIMIT, WINDOW )
   PrintDeployerDetails();
 
   console.log("\nDeploying Implementation contract...")

scripts/deployWithFixtures.js

@@ -2,15 +2,21 @@ const { ethers } = require("hardhat");
 const { PrintDeployerDetails, PrintContractDetails } = require('./utils');
 const { ValidateEnvironmentVariables } = require('./utils/helpers');
 
-const { DELEGATE_ADDRESS } = process.env;
+const { DELEGATE_ADDRESS, DESTINATION_EID, LIMIT, WINDOW } = process.env;
 
 const OFT_WRAPPER_CONTRACT_NAME = "OFTWrapper";
 const PAXOS_TOKEN_FIXTURE = "PaxosTokenFixture"
 const LZ_ENDPOINT_FIXTURE = "LzEndpointFixture"
 
+const rateLimitConfig = {
+  dstEid: DESTINATION_EID,
+  limit: LIMIT,
+  window: WINDOW
+}
+
 //Only used for local testing or sepolia.
 async function main() {
-  ValidateEnvironmentVariables([DELEGATE_ADDRESS])
+  ValidateEnvironmentVariables([DELEGATE_ADDRESS, DESTINATION_EID, LIMIT, WINDOW])
   PrintDeployerDetails();
   const tokenContractFactoryImplementation = await ethers.getContractFactory(PAXOS_TOKEN_FIXTURE);
   let tokenContractImplementation = await tokenContractFactoryImplementation.deploy();
@@ -22,7 +28,7 @@ async function main() {
 
   console.log("\nDeploying Implementation contract...")
   const contractFactoryImplementation = await ethers.getContractFactory(OFT_WRAPPER_CONTRACT_NAME);
-  let contractImplementation = await contractFactoryImplementation.deploy(tokenContractImplementation.address, endpointContractImplementation.address, DELEGATE_ADDRESS);
+  let contractImplementation = await contractFactoryImplementation.deploy(tokenContractImplementation.address, endpointContractImplementation.address, DELEGATE_ADDRESS, [rateLimitConfig]);
   PrintContractDetails(contractImplementation, OFT_WRAPPER_CONTRACT_NAME);
 
 }

test/OFTProxyBasicTest.js

@@ -1,9 +1,10 @@
-const { deployOFTWrapper } = require('./helpers/fixtures');
+const { deployOFTWrapper, LIMIT } = require('./helpers/fixtures');
 const { loadFixture } = require("@nomicfoundation/hardhat-network-helpers");
-const { assert } = require('chai');
+const { assert, expect } = require('chai');
 
 const CREDIT_AMOUNT = 10000;
 const DEBIT_AMOUNT = 3000;
+const NEW_LIMIT = ethers.utils.parseEther('900')
 
 describe('OFTWrapper Test', function () {
 
@@ -32,6 +33,30 @@ describe('OFTWrapper Test', function () {
       });
     });
 
+    describe('setRateLimits', function () {
+      it('can succesfully call setRateLimits', async function () {
+        const newRateLimitConfig = {
+          dstEid: 1,
+          limit: NEW_LIMIT,
+          window: 100
+        }
+        await this.contract.setRateLimits([newRateLimitConfig])
+        const rateLimitConfig = await this.contract.rateLimits(newRateLimitConfig.dstEid);
+        console.log(rateLimitConfig)
+        assert.equal(rateLimitConfig.limit.toString(), newRateLimitConfig.limit.toString())
+        assert.equal(rateLimitConfig.window, newRateLimitConfig.window)
+      });
+
+      it('cannot call setRateLimits from non owner', async function () {
+        const newRateLimitConfig = {
+          dstEid: 1,
+          limit: NEW_LIMIT,
+          window: 100
+        }
+        await expect(this.contract.connect(this.admin).setRateLimits([newRateLimitConfig])).to.be.reverted;
+      });
+    });
+
     describe('credit', function () {
       it('can succesfully call credit', async function () {
         await this.contract.credit(this.owner.address, CREDIT_AMOUNT, 1);
@@ -48,6 +73,24 @@ describe('OFTWrapper Test', function () {
         let amount = await this.tokenFixture.balanceOf(this.owner.address)
         assert.equal(amount, CREDIT_AMOUNT - DEBIT_AMOUNT)
       });
+
+      it('cannot call debit if rate limit exceeded', async function () {
+        await this.contract.credit(this.owner.address, NEW_LIMIT + 100, 1);
+        await expect(this.contract.debit(this.owner.address, NEW_LIMIT + 100, 100, 1)).to.be.revertedWithCustomError(this.contract, "RateLimitExceeded")
+      });
+
+      it('can call debit if rate limit updated to higher amount', async function () {
+        await this.contract.credit(this.owner.address, NEW_LIMIT + 100, 1);
+        const newRateLimitConfig = {
+          dstEid: 1,
+          limit: NEW_LIMIT + NEW_LIMIT,
+          window: 100
+        }
+        await this.contract.setRateLimits([newRateLimitConfig])
+        await this.contract.debit(this.owner.address, NEW_LIMIT + 100, 100, 1)
+        let amount = await this.tokenFixture.balanceOf(this.owner.address)
+        assert.equal(amount, 0)
+      });
     });
 
 });

test/OFTProxySendTest.js

@@ -56,8 +56,18 @@ describe('OFTWrapper Send Test', function () {
     mockEndpointA = await EndpointV2Mock.deploy(eidA);
     mockEndpointB = await EndpointV2Mock.deploy(eidB);
     // Deploying two instances of MyOFT contract and linking them to the mock LZEndpoint
-    myOFTA = await MyOFT.connect(ownerA).deploy(tokenFixture.address, mockEndpointA.address, ownerA.address)
-    myOFTB = await MyOFT.connect(ownerB).deploy(tokenFixtureB.address, mockEndpointB.address, ownerB.address)
+    const rateLimitConfigA = {
+      dstEid: 2,
+      limit: ethers.utils.parseEther('1000'),
+      window: 100
+   }
+    const rateLimitConfigB = {
+      dstEid: 1,
+      limit: ethers.utils.parseEther('1000'),
+      window: 100
+   }
+    myOFTA = await MyOFT.connect(ownerA).deploy(tokenFixture.address, mockEndpointA.address, ownerA.address, [rateLimitConfigA])
+    myOFTB = await MyOFT.connect(ownerB).deploy(tokenFixtureB.address, mockEndpointB.address, ownerB.address, [rateLimitConfigB])
 
     // Setting destination endpoints in the LZEndpoint mock for each MyOFT instance
     await mockEndpointA.setDestLzEndpoint(myOFTB.address, mockEndpointB.address);

test/helpers/fixtures.js

@@ -3,16 +3,22 @@ const { ethers } = require("hardhat");
 const PAXOS_TOKEN_FIXTURE = "PaxosTokenFixture"
 const LZ_ENDPOINT_FIXTURE = "LzEndpointFixture"
 const OFT_WRAPPER = "OFTWrapperFixture"
+const LIMIT = ethers.utils.parseEther('1000')
 
 async function deployOFTWrapper() {
     const [owner, admin, recipient, assetProtectionRole, acc, acc2, acc3] = await ethers.getSigners();
+    const rateLimitConfig = {
+       dstEid: 1,
+       limit: LIMIT,
+       window: 100
+    }
     const lzEndpoint = await ethers.deployContract(LZ_ENDPOINT_FIXTURE, [1, acc2.address])
     const tokenFixture = await ethers.deployContract(PAXOS_TOKEN_FIXTURE)
-    const contract = await ethers.deployContract(OFT_WRAPPER, [tokenFixture.address, lzEndpoint.address, acc2.address])
+    const contract = await ethers.deployContract(OFT_WRAPPER, [tokenFixture.address, lzEndpoint.address, acc2.address, [rateLimitConfig]])
     return { owner, admin, recipient, acc, acc2, acc3, assetProtectionRole, contract, tokenFixture }
 
 }
 
 module.exports = {
-  deployOFTWrapper
+  deployOFTWrapper,
 }