shutter-service: add initial ShutterRegistry

Author: fredo

foundry.toml

@@ -2,7 +2,7 @@
 src = "src"
 out = "out"
 libs = ["lib"]
-solc = "0.8.22"
+solc = "0.8.28"
 
 extra_output = ['devdoc', 'userdoc', 'metadata', 'storageLayout']
 bytecode_hash = 'none'

src/shutter-service/ShutterRegistry.sol

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.28;
+
+import "openzeppelin/contracts/access/Ownable.sol";
+
+/**
+ * @title ShutterRegistry
+ * @dev A contract for managing the registration of identities with timestamps, ensuring unique and future-dated registrations.
+ * Inherits from OpenZeppelin's Ownable contract to enable ownership-based access control.
+ */
+contract ShutterRegistry is Ownable {
+
+    // Custom error for when an identity is already registered.
+    error AlreadyRegistered();
+
+    // Custom error for when a provided timestamp is in the past.
+    error TimestampInThePast();
+
+    /**
+     * @dev Mapping to store registration timestamps for each identity.
+     *      The identity is represented as a `bytes32` hash and mapped to a uint64 timestamp.
+     */
+    mapping(bytes32 identity => uint64 timestamp) public registrations;
+
+    /**
+     * @dev Emitted when a new identity is successfully registered.
+     * @param identityPrefix The raw prefix input used to derive the registered identity hash.
+     * @param sender The address of the account that performed the registration.
+     * @param timestamp The timestamp associated with the registered identity.
+     */
+    event IdentityRegistered(
+        bytes32 identityPrefix,
+        address sender,
+        uint64 timestamp
+    );
+
+    /**
+     * @dev Initializes the contract and assigns ownership to the deployer.
+     */
+    constructor() Ownable(msg.sender) {}
+
+    /**
+     * @notice Registers a new identity with a specified timestamp.
+     * @dev The identity is derived by hashing the provided `identityPrefix` concatenated with the sender's address.
+     * @param identityPrefix The input used to derive the identity hash.
+     * @param timestamp The future timestamp to be associated with the identity.
+     * @custom:requirements
+     * - The identity must not already be registered.
+     * - The provided timestamp must not be in the past.
+     */
+    function register(bytes32 identityPrefix, uint64 timestamp) external {
+        // Generate the identity hash from the provided prefix and the sender's address.
+        bytes32 identity = keccak256(abi.encodePacked(identityPrefix, msg.sender));
+
+        // Ensure the identity is not already registered.
+        require(registrations[identity] == uint64(0), AlreadyRegistered());
+
+        // Ensure the timestamp is not in the past.
+        require(timestamp >= block.timestamp, TimestampInThePast());
+
+        // Store the registration timestamp.
+        registrations[identity] = timestamp;
+
+        // Emit the IdentityRegistered event.
+        emit IdentityRegistered(
+            identityPrefix,
+            msg.sender,
+            timestamp
+        );
+    }
+}