feat(merkle-distributor): Make claim only callable by recipient or whitelisted claimer (#195)

* feat(merkle-distributor): Make claim only callable by recipient

Intended use case is for `claim` to reset user's off-chain reward rate (used to produce rewards that would be seeded into this contract). Therefore, claim should only be callable by end recipient

* Add claimFor

* Reset

* Update MerkleDistributor.sol

* Update MerkleDistributor.ts

* Update MerkleDistributor.ts

* Update MerkleDistributor.ts

* Update MerkleDistributor.sol

* Use interface

* WIP

* Bump contracts to 0.40

* Update contracts/merkle-distributor/AcrossMerkleDistributor.sol

Co-authored-by: Chris Maree <christopher.maree@gmail.com>

* Update package.json

* Update AcrossMerkleDistributor.sol

Co-authored-by: Chris Maree <christopher.maree@gmail.com>

Author: nicholaspai

contracts/merkle-distributor/AcrossMerkleDistributor.sol

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+pragma solidity ^0.8.0;
+
+import "@uma/core/contracts/merkle-distributor/implementation/MerkleDistributor.sol";
+
+/**
+ * @title  Extended MerkleDistributor contract.
+ * @notice Adds additional constraints governing who can claim leaves from merkle windows.
+ */
+contract AcrossMerkleDistributor is MerkleDistributor {
+    // Addresses that can claim on user's behalf. Useful to get around the requirement that claim recipient
+    // must also be claimer.
+    mapping(address => bool) public whitelistedClaimers;
+
+    /****************************************
+     *                EVENTS
+     ****************************************/
+    event WhitelistedClaimer(address indexed claimer, bool indexed whitelist);
+
+    /****************************
+     *      ADMIN FUNCTIONS
+     ****************************/
+
+    /**
+     * @notice Updates whitelisted claimer status.
+     * @dev Callable only by owner.
+     * @param newContract Reset claimer contract to this address.
+     * @param whitelist True to whitelist claimer, False otherwise.
+     */
+    function whitelistClaimer(address newContract, bool whitelist) external onlyOwner {
+        whitelistedClaimers[newContract] = whitelist;
+        emit WhitelistedClaimer(newContract, whitelist);
+    }
+
+    /****************************
+     *    NON-ADMIN FUNCTIONS
+     ****************************/
+
+    /**
+     * @notice Batch claims to reduce gas versus individual submitting all claims. Method will fail
+     *         if any individual claims within the batch would fail.
+     * @dev    All claim recipients must be equal to msg.sender or claimer must be whitelisted.
+     * @param claims array of claims to claim.
+     */
+    function claimMulti(Claim[] memory claims) public override {
+        if (!whitelistedClaimers[msg.sender]) {
+            uint256 claimCount = claims.length;
+            for (uint256 i = 0; i < claimCount; i++) {
+                require(claims[i].account == msg.sender, "invalid claimer");
+            }
+        }
+        super.claimMulti(claims);
+    }
+
+    /**
+     * @notice Claim amount of reward tokens for account, as described by Claim input object.
+     * @dev    Claim recipient must be equal to msg.sender or caller must be whitelisted.
+     * @param _claim claim object describing amount, accountIndex, account, window index, and merkle proof.
+     */
+    function claim(Claim memory _claim) public override {
+        require(whitelistedClaimers[msg.sender] || _claim.account == msg.sender, "invalid claimer");
+        super.claim(_claim);
+    }
+}

contracts/merkle-distributor/MerkleDistributor.sol

@@ -1,6 +1,6 @@
 {
   "name": "@across-protocol/contracts-v2",
-  "version": "1.0.5",
+  "version": "1.0.6",
   "author": "UMA Team",
   "license": "AGPL-3.0",
   "repository": {
@@ -37,7 +37,7 @@
     "@openzeppelin/contracts": "^4.7.3",
     "@uma/common": "^2.28.0",
     "@uma/contracts-node": "^0.3.18",
-    "@uma/core": "^2.38.0",
+    "@uma/core": "^2.40.0",
     "@uma/merkle-distributor": "^1.3.38",
     "arb-bridge-eth": "^0.7.4",
     "arb-bridge-peripherals": "^1.0.5"

package.json

@@ -31,7 +31,7 @@ async function _findL2TokenFromTokenList(l2ChainId: number, l1TokenAddress: stri
   }
   if (l2ChainId === 137) {
     const response = await fetch(
-      "https://raw.githubusercontent.com/maticnetwork/polygon-token-list/master/src/tokens/allTokens.json"
+      "https://raw.githubusercontent.com/maticnetwork/polygon-token-list/master/src/tokens/polygonTokens.json"
     );
     const body = await response.text();
     const tokenList = JSON.parse(body);

tasks/utils.ts

@@ -1,4 +1,6 @@
-import { toWei, utf8ToHex, toBN, createRandomBytes32, ethers, hre } from "./utils";
+import { toWei, utf8ToHex, toBN, createRandomBytes32 } from "./utils";
+
+import { ethers } from "ethers";
 
 export { TokenRolesEnum } from "@uma/common";