Update ERC-6538 contract and tests

.github/workflows/ci.yml

@@ -35,6 +35,27 @@ jobs:
       - name: Run tests
         run: forge test
 
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: 1.21.5
+          cache: False
+
+      - name: Install `jd` CLI
+        run: go install github.com/josephburnett/jd@latest
+
+      - name: Ensure correctness of the `IERC5564Announcer` interface
+        run: |
+          diff=$(jd -set <(jq '.abi' out/ERC5564Announcer.sol/ERC5564Announcer.json) <(jq '.abi' out/IERC5564Announcer.sol/IERC5564Announcer.json))
+          if [[ -n $diff ]]; then exit 1; fi
+
+      - name: Ensure correctness of the `IERC6538Registry` interface
+        run: |
+          echo $(jd -set <(jq '.abi' out/ERC6538Registry.sol/ERC6538Registry.json) <(jq '.abi' out/IERC6538Registry.sol/IERC6538Registry.json)) > diff.txt
+          echo "@ [[\"set\"],{}] - {\"inputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"constructor\"}" > expected_diff.txt
+          diff=$(diff diff.txt expected_diff.txt)
+          if [[ -n $diff ]]; then exit 1; fi
+
   coverage:
     runs-on: ubuntu-latest
     steps:
@@ -110,7 +131,7 @@ jobs:
       - uses: actions/checkout@v3
 
       - name: Run Slither
-        uses: crytic/[email protected].0
+        uses: crytic/[email protected].1
         id: slither # Required to reference this step in the next step.
         with:
           fail-on: none # Required to avoid failing the CI run regardless of findings.

foundry.toml

@@ -3,7 +3,7 @@
   evm_version = "paris"
   optimizer = true
   optimizer_runs = 10_000_000
-  solc_version = "0.8.20"
+  solc_version = "0.8.23"
   verbosity = 3
 
 [profile.ci]

script/Deploy.s.sol

@@ -1,7 +1,7 @@
-// SPDX-License-Identifier: UNLICENSED
+// SPDX-License-Identifier: MIT
 // slither-disable-start reentrancy-benign
 
-pragma solidity 0.8.20;
+pragma solidity 0.8.23;
 
 import {Script} from "forge-std/Script.sol";
 import {ERC5564Announcer} from "src/ERC5564Announcer.sol";
@@ -10,12 +10,24 @@ import {ERC6538Registry} from "src/ERC6538Registry.sol";
 contract Deploy is Script {
   ERC5564Announcer announcer;
   ERC6538Registry registry;
+  address deployer = 0x4e59b44847b379578588920cA78FbF26c0B4956C;
+  bytes32 salt = "";
 
   function run() public {
+    bytes memory ERC5564CreationCode = abi.encodePacked(type(ERC5564Announcer).creationCode);
+    bytes memory ERC6538CreationCode = abi.encodePacked(type(ERC6538Registry).creationCode);
+    address ERC5564ComputedAddress =
+      computeCreate2Address(salt, keccak256(ERC5564CreationCode), deployer);
+    address ERC6538ComputedAddress =
+      computeCreate2Address(salt, keccak256(ERC6538CreationCode), deployer);
+
     vm.broadcast();
-    announcer = new ERC5564Announcer();
+    announcer = new ERC5564Announcer{salt: salt}();
 
     vm.broadcast();
-    registry = new ERC6538Registry();
+    registry = new ERC6538Registry{salt: salt}();
+
+    require(address(announcer) == ERC5564ComputedAddress, "announce address mismatch");
+    require(address(registry) == ERC6538ComputedAddress, "registry address mismatch");
   }
 }

src/ERC5564Announcer.sol

@@ -1,13 +1,37 @@
-// SPDX-License-Identifier: UNLICENSED
-pragma solidity 0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
 
-import {IERC5564Announcer} from "./interfaces/IERC5564Announcer.sol";
-
-/// @dev `ERC5564Announcer` contract to emit an `Announcement` event to broadcast information about
-/// a transaction involving a stealth address. See
+/// @notice `ERC5564Announcer` contract to emit an `Announcement` event to broadcast information
+/// about a transaction involving a stealth address. See
 /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) to learn more.
-contract ERC5564Announcer is IERC5564Announcer {
-  /// @inheritdoc IERC5564Announcer
+contract ERC5564Announcer {
+  /// @notice Emitted when something is sent to a stealth address.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param caller The caller of the `announce` function that emitted this event.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender to derive the `stealthAddress`.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
+  event Announcement(
+    uint256 indexed schemeId,
+    address indexed stealthAddress,
+    address indexed caller,
+    bytes ephemeralPubKey,
+    bytes metadata
+  );
+
+  /// @notice Called by integrators to emit an `Announcement` event.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthAddress The computed stealth address for the recipient.
+  /// @param ephemeralPubKey Ephemeral public key used by the sender.
+  /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
+  /// @dev The remaining metadata can be used by the senders however they like. See
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
+  /// this metadata.
   function announce(
     uint256 schemeId,
     address stealthAddress,

src/ERC6538Registry.sol

@@ -1,45 +1,155 @@
-// SPDX-License-Identifier: UNLICENSED
-pragma solidity 0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
 
-import {IERC6538Registry} from "./interfaces/IERC6538Registry.sol";
-
-/// @dev `ERC6538Registry` contract to map accounts to their stealth meta-address. See
+/// @notice `ERC6538Registry` contract to map accounts to their stealth meta-address. See
 /// [ERC-6538](https://eips.ethereum.org/EIPS/eip-6538) to learn more.
-contract ERC6538Registry is IERC6538Registry {
-  /// @notice Maps a registrant's identifier to the scheme ID to the stealth meta-address.
+contract ERC6538Registry {
+  /// @notice Emitted when an invalid signature is provided to `registerKeysOnBehalf`.
+  error ERC6538Registry__InvalidSignature();
+
+  /// @notice Next nonce expected from `user` to use when signing for `registerKeysOnBehalf`.
   /// @dev `registrant` may be a standard 160-bit address or any other identifier.
   /// @dev `schemeId` is an integer identifier for the stealth address scheme.
-  mapping(bytes registrant => mapping(uint256 schemeId => bytes)) public stealthMetaAddressOf;
+  mapping(address registrant => mapping(uint256 schemeId => bytes)) public stealthMetaAddressOf;
 
-  /// @inheritdoc IERC6538Registry
-  function registerKeys(uint256 schemeId, bytes memory stealthMetaAddress) external {
-    bytes memory registrant = _toBytes(msg.sender);
-    stealthMetaAddressOf[registrant][schemeId] = stealthMetaAddress;
-    emit StealthMetaAddressSet(registrant, schemeId, stealthMetaAddress);
+  /// @notice A nonce used to ensure a signature can only be used once.
+  /// @dev `registrant` is the user address.
+  /// @dev `nonce` will be incremented after each valid `registerKeysOnBehalf` call.
+  mapping(address registrant => uint256) public nonceOf;
+
+  /// @notice The EIP-712 type hash used in `registerKeysOnBehalf`.
+  bytes32 public constant ERC6538REGISTRY_ENTRY_TYPE_HASH =
+    keccak256("Erc6538RegistryEntry(uint256 schemeId,bytes stealthMetaAddress,uint256 nonce)");
+
+  /// @notice The chain ID where this contract is initially deployed.
+  uint256 internal immutable INITIAL_CHAIN_ID;
+
+  /// @notice The domain separator used in this contract.
+  bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;
+
+  /// @notice Emitted when a registrant updates their stealth meta-address.
+  /// @param registrant The account that registered the stealth meta-address.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthMetaAddress The stealth meta-address.
+  /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) bases the format for stealth
+  /// meta-addresses on [ERC-3770](https://eips.ethereum.org/EIPS/eip-3770) and specifies them as:
+  ///   st:<shortName>:0x<spendingPubKey>:<viewingPubKey>
+  /// The chain (`shortName`) is implicit based on the chain the `ERC6538Registry` is deployed on,
+  /// therefore this `stealthMetaAddress` is just the compressed `spendingPubKey` and
+  /// `viewingPubKey` concatenated.
+  event StealthMetaAddressSet(
+    address indexed registrant, uint256 indexed schemeId, bytes stealthMetaAddress
+  );
+
+  constructor() {
+    INITIAL_CHAIN_ID = block.chainid;
+    INITIAL_DOMAIN_SEPARATOR = _computeDomainSeparator();
+  }
+
+  /// @notice Sets the caller's stealth meta-address for the given scheme ID.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param stealthMetaAddress The stealth meta-address to register.
+  function registerKeys(uint256 schemeId, bytes calldata stealthMetaAddress) external {
+    stealthMetaAddressOf[msg.sender][schemeId] = stealthMetaAddress;
+    emit StealthMetaAddressSet(msg.sender, schemeId, stealthMetaAddress);
   }
 
-  /// @inheritdoc IERC6538Registry
+  /// @notice Sets the `registrant`'s stealth meta-address for the given scheme ID.
+  /// @param registrant Address of the registrant.
+  /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
+  /// secp256k1, as specified in ERC-5564.
+  /// @param signature A signature from the `registrant` authorizing the registration.
+  /// @param stealthMetaAddress The stealth meta-address to register.
+  /// @dev Supports both EOA signatures and EIP-1271 signatures.
+  /// @dev Reverts if the signature is invalid.
   function registerKeysOnBehalf(
     address registrant,
     uint256 schemeId,
     bytes memory signature,
-    bytes memory stealthMetaAddress
-  ) external pure {
-    registerKeysOnBehalf(_toBytes(registrant), schemeId, signature, stealthMetaAddress);
+    bytes calldata stealthMetaAddress
+  ) external {
+    bytes32 dataHash;
+    address recoveredAddress;
+
+    unchecked {
+      dataHash = keccak256(
+        abi.encodePacked(
+          "\x19\x01",
+          DOMAIN_SEPARATOR(),
+          keccak256(
+            abi.encode(
+              ERC6538REGISTRY_ENTRY_TYPE_HASH, schemeId, stealthMetaAddress, nonceOf[registrant]++
+            )
+          )
+        )
+      );
+    }
+
+    if (signature.length == 65) {
+      bytes32 r;
+      bytes32 s;
+      uint8 v;
+      assembly ("memory-safe") {
+        r := mload(add(signature, 0x20))
+        s := mload(add(signature, 0x40))
+        v := byte(0, mload(add(signature, 0x60)))
+      }
+      recoveredAddress = ecrecover(dataHash, v, r, s);
+    }
+
+    if (
+      (
+        (recoveredAddress == address(0) || recoveredAddress != registrant)
+          && (
+            IERC1271(registrant).isValidSignature(dataHash, signature)
+              != IERC1271.isValidSignature.selector
+          )
+      )
+    ) revert ERC6538Registry__InvalidSignature();
+
+    stealthMetaAddressOf[registrant][schemeId] = stealthMetaAddress;
+    emit StealthMetaAddressSet(registrant, schemeId, stealthMetaAddress);
   }
 
-  /// @inheritdoc IERC6538Registry
-  function registerKeysOnBehalf(
-    bytes memory, // registrant
-    uint256, // schemeId
-    bytes memory, // signature
-    bytes memory // stealthMetaAddress
-  ) public pure {
-    revert("not implemented");
+  /// @notice Increments the nonce of the sender to invalidate existing signatures.
+  function incrementNonce() external {
+    unchecked {
+      nonceOf[msg.sender]++;
+    }
+  }
+
+  /// @notice Returns the domain separator used in this contract.
+  /// @dev The domain separator is re-computed if there's a chain fork.
+  function DOMAIN_SEPARATOR() public view returns (bytes32) {
+    return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : _computeDomainSeparator();
   }
 
-  /// @dev Converts an `address` to `bytes`.
-  function _toBytes(address who) internal pure returns (bytes memory) {
-    return bytes.concat(bytes32(uint256(uint160(who))));
+  /// @notice Computes the domain separator for this contract.
+  function _computeDomainSeparator() internal view returns (bytes32) {
+    return keccak256(
+      abi.encode(
+        keccak256(
+          "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
+        ),
+        keccak256("ERC6538Registry"),
+        keccak256("1.0"),
+        block.chainid,
+        address(this)
+      )
+    );
   }
 }
+
+/// @notice Interface of the ERC1271 standard signature validation method for contracts as defined
+/// in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
+interface IERC1271 {
+  /// @notice Should return whether the signature provided is valid for the provided data
+  /// @param hash Hash of the data to be signed
+  /// @param signature Signature byte array associated with _data
+  function isValidSignature(bytes32 hash, bytes memory signature)
+    external
+    view
+    returns (bytes4 magicValue);
+}

src/interfaces/IERC5564Announcer.sol

@@ -1,18 +1,18 @@
-// SPDX-License-Identifier: UNLICENSED
-pragma solidity ^0.8.0;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
 
-/// @dev Interface for calling the `ERC5564Announcer` contract, which emits an `Announcement` event
-/// to broadcast information about a transaction involving a stealth address. See
+/// @notice Interface for calling the `ERC5564Announcer` contract, which emits an `Announcement`
+/// event to broadcast information about a transaction involving a stealth address. See
 /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) to learn more.
 interface IERC5564Announcer {
-  /// @dev Emitted when something is sent to a stealth address.
+  /// @notice Emitted when something is sent to a stealth address.
   /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
   /// secp256k1, as specified in ERC-5564.
   /// @param stealthAddress The computed stealth address for the recipient.
   /// @param caller The caller of the `announce` function that emitted this event.
   /// @param ephemeralPubKey Ephemeral public key used by the sender to derive the `stealthAddress`.
   /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
-  /// The remaining metadata can be used by the senders however they like. See
+  /// @dev The remaining metadata can be used by the senders however they like. See
   /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
   /// this metadata.
   event Announcement(
@@ -23,13 +23,13 @@ interface IERC5564Announcer {
     bytes metadata
   );
 
-  /// @dev Called by integrators to emit an `Announcement` event.
+  /// @notice Called by integrators to emit an `Announcement` event.
   /// @param schemeId Identifier corresponding to the applied stealth address scheme, e.g. 1 for
   /// secp256k1, as specified in ERC-5564.
   /// @param stealthAddress The computed stealth address for the recipient.
   /// @param ephemeralPubKey Ephemeral public key used by the sender.
   /// @param metadata Arbitrary data to emit with the event. The first byte MUST be the view tag.
-  /// The remaining metadata can be used by the senders however they like. See
+  /// @dev The remaining metadata can be used by the senders however they like. See
   /// [ERC-5564](https://eips.ethereum.org/EIPS/eip-5564) for recommendations on how to structure
   /// this metadata.
   function announce(