fix(gateway-contracts): use contractsChainId in delegate request eip712 verification (#427)

Author: melanciani

gateway-contracts/.github/ISSUE_TEMPLATE/contracts_bug_report.md

@@ -20,8 +20,7 @@ Include screenshots, relevant logs, or traces if available.
 
 ### **Smart Contract Code Snippet**
 
-If applicable, provide a minimal reproducible example of the smart contract code highlighting the part where the issue
-occurs:
+If applicable, provide a minimal reproducible example of the smart contract code highlighting the part where the issue occurs:
 
 <details><summary>Example</summary>
 <p>

gateway-contracts/.github/ISSUE_TEMPLATE/docs_bug_report.md

@@ -14,8 +14,7 @@ Please provide a link to the page where the issue is located:
 
 ### **Description**
 
-Describe in detail what part of the documentation is unclear or provide a clear and detailed description of the bug.
-Include any inconsistencies, typos, broken links, or missing information.
+Describe in detail what part of the documentation is unclear or provide a clear and detailed description of the bug. Include any inconsistencies, typos, broken links, or missing information.
 
 <details><summary>For example:</summary>
 <p>
@@ -69,5 +68,4 @@ Choose the impact of the bug on the documentation quality and user experience:
 
 ---
 
-By including these details, we can ensure a faster and more accurate resolution for your issue. Thank you for helping
-improve the `fhevm Gateway's documentation`!
+By including these details, we can ensure a faster and more accurate resolution for your issue. Thank you for helping improve the `fhevm Gateway's documentation`!

gateway-contracts/.github/ISSUE_TEMPLATE/feature_request.md

@@ -6,8 +6,7 @@ labels: enhancement
 assignees: ""
 ---
 
-**Is your feature request related to a problem? Please describe.** A clear and concise description of what the problem
-is. Ex. I'm always frustrated when [...]
+**Is your feature request related to a problem? Please describe.** A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
 
 **Describe the solution you'd like** A clear and concise description of what you want to happen.
 

gateway-contracts/README.md

@@ -1,8 +1,6 @@
 ## Introduction
 
-The **FHEVM Gateway** is a set of smart contracts that enables decrypting FHE ciphertexts from different host chains. It
-acts as an intermediary between the chains, the Key Management Service (KMS) and the coprocessors found within the FHEVM
-protocol. These contracts are responsible for:
+The **FHEVM Gateway** is a set of smart contracts that enables decrypting FHE ciphertexts from different host chains. It acts as an intermediary between the chains, the Key Management Service (KMS) and the coprocessors found within the FHEVM protocol. These contracts are responsible for:
 
 - Verifying the legitimacy of decryption requests
 - Centralizing multi-chain ciphertexts access
@@ -11,14 +9,14 @@ protocol. These contracts are responsible for:
 
 ## Main features
 
-| Contract            | Description                                                 | Features                                                                                                                          |
-| ------------------- | ----------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- |
-| `Decryption`        | Decrypt FHE ciphertexts                                     | - Request a public decryption<br>- Request a user decryption<br>- Request a delegated user decryption                             |
-| `InputVerification` | Verify an input's zero-knowledge proof of knowledge (ZKPoK) | - Verify a ZKPoK<br>- Reject a ZKPoK                                                                                              |
-| `MultichainAcl`     | Centralize Access Control Lists (ACL) from all host chains  | - Grant account access to ciphertexts<br>- Authorize public decryption of ciphertexts<br>- Delegate account access to ciphertexts |
-| `CiphertextCommits` | Store ciphertext commitments from all host chains           | - Store regular ciphertext commitments<br>- Store Switch and Squash (SNS) ciphertext commitments                                  |
-| `KmsManagement`     | Orchestrate KMS-related materials                           | 🚧 _Not in use yet_ 🚧                                                                                                            |
-| `GatewayConfig`     | Administer configuration settings                           | - Register KMS nodes, coprocessors and host chains. <br> - Update KMS nodes, coprocessors and host chains.                        |
+| Contract | Description | Features |
+| --- | --- | --- |
+| `Decryption` | Decrypt FHE ciphertexts | - Request a public decryption<br>- Request a user decryption<br>- Request a delegated user decryption |
+| `InputVerification` | Verify an input's zero-knowledge proof of knowledge (ZKPoK) | - Verify a ZKPoK<br>- Reject a ZKPoK |
+| `MultichainAcl` | Centralize Access Control Lists (ACL) from all host chains | - Grant account access to ciphertexts<br>- Authorize public decryption of ciphertexts<br>- Delegate account access to ciphertexts |
+| `CiphertextCommits` | Store ciphertext commitments from all host chains | - Store regular ciphertext commitments<br>- Store Switch and Squash (SNS) ciphertext commitments |
+| `KmsManagement` | Orchestrate KMS-related materials | 🚧 _Not in use yet_ 🚧 |
+| `GatewayConfig` | Administer configuration settings | - Register KMS nodes, coprocessors and host chains. <br> - Update KMS nodes, coprocessors and host chains. |
 
 ## Getting started
 
@@ -34,7 +32,6 @@ Documentation can be found [here](./docs/SUMMARY.md).
 </picture>
 </a>
 
-🌟 If you find this project helpful or interesting, please consider giving it a star on GitHub! Your support helps to
-grow the community and motivates further development.
+🌟 If you find this project helpful or interesting, please consider giving it a star on GitHub! Your support helps to grow the community and motivates further development.
 
 [![GitHub stars](https://img.shields.io/github/stars/zama-ai/fhevm?style=social)](https://github.com/zama-ai/fhevm/)

gateway-contracts/contracts/Decryption.sol

@@ -150,7 +150,7 @@ contract Decryption is
     /// @dev they can still define their own private constants with the same name.
     string private constant CONTRACT_NAME = "Decryption";
     uint256 private constant MAJOR_VERSION = 0;
-    uint256 private constant MINOR_VERSION = 2;
+    uint256 private constant MINOR_VERSION = 3;
     uint256 private constant PATCH_VERSION = 0;
 
     /// @notice The contract's variable storage struct (@dev see ERC-7201)
@@ -204,16 +204,16 @@ contract Decryption is
     /// @dev Contract name and version for EIP712 signature validation are defined here
     /// @dev This function needs to be public in order to be called by the UUPS proxy.
     /// @custom:oz-upgrades-validate-as-initializer
-    function initializeFromEmptyProxy() public virtual onlyFromEmptyProxy reinitializer(4) {
+    function initializeFromEmptyProxy() public virtual onlyFromEmptyProxy reinitializer(5) {
         __EIP712_init(CONTRACT_NAME, "1");
         __Ownable_init(owner());
         __Pausable_init();
     }
 
     /**
-     * @notice Re-initializes the contract from V1.
+     * @notice Re-initializes the contract from V2.
      */
-    function reinitializeV2() public virtual reinitializer(4) {}
+    function reinitializeV3() public virtual reinitializer(5) {}
 
     /// @dev See {IDecryption-publicDecryptionRequest}.
     function publicDecryptionRequest(bytes32[] calldata ctHandles) external virtual whenNotPaused {
@@ -643,6 +643,20 @@ contract Decryption is
             );
     }
 
+    /// @notice Computes the hash of the hashed struct using a custom chain ID for the eip712 domain
+    /// @param chainId The chain ID
+    /// @param structHash The hash of the struct
+    /// @dev This could be improved along https://github.com/zama-ai/fhevm/issues/424
+    function _hashTypedDataV4CustomChainId(
+        uint256 chainId,
+        bytes32 structHash
+    ) internal view virtual returns (bytes32) {
+        bytes32 domainSeparatorV4 = keccak256(
+            abi.encode(DOMAIN_TYPE_HASH, _EIP712NameHash(), _EIP712VersionHash(), chainId, address(this))
+        );
+        return MessageHashUtils.toTypedDataHash(domainSeparatorV4, structHash);
+    }
+
     /// @notice Computes the hash of a given UserDecryptRequestVerification structured data.
     /// @param userDecryptRequestVerification The UserDecryptRequestVerification structure to hash.
     /// @return The hash of the UserDecryptRequestVerification structure.
@@ -659,16 +673,7 @@ contract Decryption is
                 userDecryptRequestVerification.durationDays
             )
         );
-        bytes32 domainSeparatorV4 = keccak256(
-            abi.encode(
-                DOMAIN_TYPE_HASH,
-                _EIP712NameHash(),
-                _EIP712VersionHash(),
-                userDecryptRequestVerification.contractsChainId,
-                address(this)
-            )
-        );
-        return MessageHashUtils.toTypedDataHash(domainSeparatorV4, structHash);
+        return _hashTypedDataV4CustomChainId(userDecryptRequestVerification.contractsChainId, structHash);
     }
 
     /// @notice Computes the hash of a given DelegatedUserDecryptRequestVerification structured data.
@@ -677,20 +682,18 @@ contract Decryption is
     function _hashDelegatedUserDecryptRequestVerification(
         DelegatedUserDecryptRequestVerification memory delegatedUserDecryptRequestVerification
     ) internal view virtual returns (bytes32) {
-        return
-            _hashTypedDataV4(
-                keccak256(
-                    abi.encode(
-                        EIP712_DELEGATED_USER_DECRYPT_REQUEST_TYPE_HASH,
-                        keccak256(delegatedUserDecryptRequestVerification.publicKey),
-                        keccak256(abi.encodePacked(delegatedUserDecryptRequestVerification.contractAddresses)),
-                        delegatedUserDecryptRequestVerification.delegatorAddress,
-                        delegatedUserDecryptRequestVerification.contractsChainId,
-                        delegatedUserDecryptRequestVerification.startTimestamp,
-                        delegatedUserDecryptRequestVerification.durationDays
-                    )
-                )
-            );
+        bytes32 structHash = keccak256(
+            abi.encode(
+                EIP712_DELEGATED_USER_DECRYPT_REQUEST_TYPE_HASH,
+                keccak256(delegatedUserDecryptRequestVerification.publicKey),
+                keccak256(abi.encodePacked(delegatedUserDecryptRequestVerification.contractAddresses)),
+                delegatedUserDecryptRequestVerification.delegatorAddress,
+                delegatedUserDecryptRequestVerification.contractsChainId,
+                delegatedUserDecryptRequestVerification.startTimestamp,
+                delegatedUserDecryptRequestVerification.durationDays
+            )
+        );
+        return _hashTypedDataV4CustomChainId(delegatedUserDecryptRequestVerification.contractsChainId, structHash);
     }
 
     /// @notice Computes the hash of a given UserDecryptResponseVerification structured data.

gateway-contracts/docs/README.md

@@ -1,6 +1,8 @@
 ---
 description: >-
   The fhevm Gateway.
+
+
 layout:
   title:
     visible: true
@@ -24,8 +26,7 @@ Learn the basics of fhevm Gateway, set it up, and make it run with ease.
 
 ### Supports
 
-Ask technical questions and discuss with the community. Our team of experts usually answers within 24 hours in working
-days.
+Ask technical questions and discuss with the community. Our team of experts usually answers within 24 hours in working days.
 
 - [Community forum](https://community.zama.ai/c/fhevm/15)
 - [Discord channel](https://discord.com/invite/fhe-org)
@@ -44,5 +45,4 @@ Collaborate with us to advance the FHE spaces and drive innovation together.
 
 ---
 
-We value your feedback! [Take a 5-question developer survey](http://zama.ai/developer-survey) to improve the fhevm
-Gateway and the documentation and help other developers use FHE.
+We value your feedback! [Take a 5-question developer survey](http://zama.ai/developer-survey) to improve the fhevm Gateway and the documentation and help other developers use FHE.