Improve Reverse Resolver Introspection (#498)

* bumped @unruggable/gateways @namestone/ezccip and ethers
* expanded INameReverser — now sufficient to identify a "reverse" resolver
* added IVerifiableResolver to ChainReverseResolver
* reduced some duplicated constants
* added fuzz test

Author: adraffy

bun.lock

@@ -14,11 +14,11 @@ abstract contract AbstractReverseResolver is
     INameReverser,
     ERC165
 {
-    /// @notice The coin type for the resolver.
+    /// @inheritdoc INameReverser
     uint256 public immutable coinType;
 
-    /// @notice The address returned by `addr(coinType)` for the resolver.
-    address private immutable registrar;
+	/// @inheritdoc INameReverser
+    address public immutable chainRegistrar;
 
     /// @notice `resolve()` was called with a profile other than `name()` or `addr(*)`.
     /// @dev Error selector: `0x7b1c461b`
@@ -28,22 +28,22 @@ abstract contract AbstractReverseResolver is
     /// @dev Error selector: `0x5fe9a5df`
     error UnreachableName(bytes name);
 
-    constructor(uint256 _coinType, address _registrar) {
+    constructor(uint256 _coinType, address registrar) {
         coinType = _coinType;
-        registrar = _registrar;
+        chainRegistrar = registrar;
     }
 
     /// @inheritdoc ERC165
     function supportsInterface(
         bytes4 interfaceId
-    ) public view override returns (bool) {
+    ) public view virtual override returns (bool) {
         return
             interfaceId == type(IExtendedResolver).interfaceId ||
             interfaceId == type(INameReverser).interfaceId ||
             super.supportsInterface(interfaceId);
     }
 
-    /// @notice The EVM Chain ID corresponding to the `coinType`.
+    /// @inheritdoc INameReverser
     function chainId() external view returns (uint32) {
         return ENSIP19.chainFromCoinType(coinType);
     }
@@ -86,14 +86,14 @@ abstract contract AbstractReverseResolver is
             (bool valid, ) = ENSIP19.parseNamespace(name, 0);
             if (!valid) revert UnreachableName(name);
             return
-                abi.encode(coinType == COIN_TYPE_ETH ? registrar : address(0));
+                abi.encode(coinType == COIN_TYPE_ETH ? chainRegistrar : address(0));
         } else if (selector == IAddressResolver.addr.selector) {
             (bool valid, ) = ENSIP19.parseNamespace(name, 0);
             if (!valid) revert UnreachableName(name);
             (, uint256 ct) = abi.decode(data[4:], (bytes32, uint256));
             return
                 abi.encode(
-                    coinType == ct ? abi.encodePacked(registrar) : new bytes(0)
+                    coinType == ct ? abi.encodePacked(chainRegistrar) : new bytes(0)
                 );
         } else {
             revert UnsupportedResolverProfile(selector);

contracts/reverseResolver/AbstractReverseResolver.sol

@@ -1,21 +1,27 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.17;
 
+import {ERC165} from "@openzeppelin/contracts-v5/utils/introspection/ERC165.sol";
 import {Ownable} from "@openzeppelin/contracts-v5/access/Ownable.sol";
 
 import {GatewayFetchTarget, IGatewayVerifier} from "@unruggable/gateways/GatewayFetchTarget.sol";
 import {GatewayFetcher, GatewayRequest, RequestOverflow} from "@unruggable/gateways/GatewayFetcher.sol";
 
 import {AbstractReverseResolver} from "./AbstractReverseResolver.sol";
 import {IStandaloneReverseRegistrar} from "../reverseRegistrar/IStandaloneReverseRegistrar.sol";
+import {IVerifiableResolver} from "../resolvers/profiles/IVerifiableResolver.sol";
 import {INameReverser} from "./INameReverser.sol";
+import {ENSIP19} from "../utils/ENSIP19.sol";
 
 /// @title Chain Reverse Resolver
 /// @notice Reverses an EVM address using the first non-null response from the following sources:
-///         1. `L2ReverseRegistrar` on L2 chain via Unruggable Gateway
-///         2. `IStandaloneReverseRegistrar` for "default.reverse"
+///
+/// 1. `L2ReverseRegistrar` on L2 chain via Unruggable Gateway
+/// 2. `IStandaloneReverseRegistrar` for "default.reverse"
+///
 contract ChainReverseResolver is
     AbstractReverseResolver,
+	IVerifiableResolver,
     GatewayFetchTarget,
     Ownable
 {
@@ -27,9 +33,6 @@ contract ChainReverseResolver is
     /// @notice The reverse registrar contract for "default.reverse".
     IStandaloneReverseRegistrar public immutable defaultRegistrar;
 
-    /// @notice The reverse registrar address on the L2 chain.
-    address public immutable l2Registrar;
-
     /// @notice The verifier contract for the L2 chain.
     IGatewayVerifier public gatewayVerifier;
 
@@ -46,16 +49,34 @@ contract ChainReverseResolver is
         address _owner,
         uint256 coinType,
         IStandaloneReverseRegistrar _defaultRegistrar,
-        address _l2Registrar,
+        address _chainRegistrar,
         IGatewayVerifier verifier,
         string[] memory gateways
-    ) Ownable(_owner) AbstractReverseResolver(coinType, _l2Registrar) {
+    ) Ownable(_owner) AbstractReverseResolver(coinType, _chainRegistrar) {
         defaultRegistrar = _defaultRegistrar;
-        l2Registrar = _l2Registrar;
         gatewayVerifier = verifier;
         gatewayURLs = gateways;
     }
 
+    /// @inheritdoc ERC165
+    function supportsInterface(
+        bytes4 interfaceId
+    ) public view override returns (bool) {
+        return
+            interfaceId == type(IVerifiableResolver).interfaceId ||
+            super.supportsInterface(interfaceId);
+    }
+
+	/// @inheritdoc IVerifiableResolver
+    function verifierMetadata(
+        bytes memory name
+    ) external view returns (address verifier, string[] memory gateways) {
+		 (bytes memory a, uint256 ct) = ENSIP19.parse(name);
+		 if (a.length == 20 && ct == coinType) {
+			return (address(gatewayVerifier), gatewayURLs);
+		 }
+	}
+
     /// @notice Set gateway URLs.
     /// @param gateways The new gateway URLs.
     function setGatewayURLs(string[] memory gateways) external onlyOwner {
@@ -75,7 +96,7 @@ contract ChainReverseResolver is
         address addr
     ) internal view override returns (string memory) {
         GatewayRequest memory req = GatewayFetcher.newRequest(1);
-        req.setTarget(l2Registrar); // target L2 registrar
+        req.setTarget(chainRegistrar);
         req.setSlot(NAMES_SLOT).push(addr).follow().readBytes(); // names[addr]
         req.setOutput(0);
         fetch(
@@ -118,8 +139,8 @@ contract ChainReverseResolver is
         GatewayRequest memory req = GatewayFetcher.newRequest(
             uint8(addrs.length)
         );
-        req.setTarget(l2Registrar); // target L2 registrar
-        for (uint256 i; i < addrs.length; i++) {
+        req.setTarget(chainRegistrar); // target L2 registrar
+        for (uint256 i; i < addrs.length; ++i) {
             req.setSlot(NAMES_SLOT).push(addrs[i]).follow().readBytes(); // names[addr[i]]
             req.setOutput(uint8(i));
         }
@@ -144,7 +165,7 @@ contract ChainReverseResolver is
     ) external view returns (string[] memory names) {
         address[] memory addrs = abi.decode(extraData, (address[]));
         names = new string[](addrs.length);
-        for (uint256 i; i < addrs.length; i++) {
+        for (uint256 i; i < addrs.length; ++i) {
             string memory name = string(values[i]);
             if (bytes(name).length == 0) {
                 name = defaultRegistrar.nameForAddr(addrs[i]);

contracts/reverseResolver/ChainReverseResolver.sol

@@ -9,28 +9,23 @@ import {COIN_TYPE_DEFAULT} from "../utils/ENSIP19.sol";
 /// @title Default Reverse Resolver
 /// @notice Reverses an EVM address using the `IStandaloneReverseRegistrar` for "default.reverse".
 contract DefaultReverseResolver is AbstractReverseResolver {
-    /// @notice The reverse registrar contract for "default.reverse".
-    IStandaloneReverseRegistrar public immutable defaultRegistrar;
-
     constructor(
-        IStandaloneReverseRegistrar _defaultRegistrar
-    ) AbstractReverseResolver(COIN_TYPE_DEFAULT, address(_defaultRegistrar)) {
-        defaultRegistrar = _defaultRegistrar;
-    }
+        IStandaloneReverseRegistrar defaultRegistrar
+    ) AbstractReverseResolver(COIN_TYPE_DEFAULT, address(defaultRegistrar)) {}
 
     /// @inheritdoc AbstractReverseResolver
     function _resolveName(
         address addr
     ) internal view override returns (string memory name) {
-        name = defaultRegistrar.nameForAddr(addr);
+        name = IStandaloneReverseRegistrar(chainRegistrar).nameForAddr(addr);
     }
 
     /// @inheritdoc INameReverser
     function resolveNames(
         address[] memory addrs
     ) external view returns (string[] memory names) {
         names = new string[](addrs.length);
-        for (uint256 i; i < addrs.length; i++) {
+        for (uint256 i; i < addrs.length; ++i) {
             names[i] = _resolveName(addrs[i]);
         }
     }