Host and Library cleanup

coprocessor/fhevm-engine/host-listener/contracts/FHEVMExecutorTest.sol

@@ -117,13 +117,15 @@ contract FHEVMExecutorTest is FHEEvents {
         emit TrivialEncrypt(msg.sender, val, toType, result);
     }
 
-    function verifyCiphertext(
+    function validateInput(
         bytes32 inputHandle,
         address userAddress,
         bytes memory inputProof,
-        FheType  inputType
+        FheType inputType
     ) public {
-        bytes32 result = bytes32(keccak256(abi.encodePacked("verifyCiphertext", inputHandle, userAddress, inputProof, inputType)));
-        emit VerifyCiphertext(msg.sender, inputHandle, userAddress, inputProof, inputType, result);
+        bytes32 result = bytes32(
+            keccak256(abi.encodePacked("validateInput", inputHandle, userAddress, inputProof, inputType))
+        );
+        emit ValidateInput(msg.sender, inputHandle, userAddress, inputProof, inputType, result);
     }
 }

coprocessor/fhevm-engine/host-listener/src/database/tfhe_event_propagate.rs

@@ -416,7 +416,7 @@ impl Database {
             | E::OwnershipTransferStarted(_)
             | E::OwnershipTransferred(_)
             | E::Upgraded(_)
-            | E::VerifyCiphertext(_)
+            | E::ValidateInput(_)
             => Ok(()),
         }
     }
@@ -637,7 +637,7 @@ fn event_to_op_int(op: &TfheContractEvents) -> FheOperation {
         | E::OwnershipTransferStarted(_)
         | E::OwnershipTransferred(_)
         | E::Upgraded(_)
-        | E::VerifyCiphertext(_) => -1,
+        | E::ValidateInput(_) => -1,
     }
 }
 
@@ -675,7 +675,7 @@ pub fn event_name(op: &TfheContractEvents) -> &'static str {
         E::OwnershipTransferStarted(_) => "OwnershipTransferStarted",
         E::OwnershipTransferred(_) => "OwnershipTransferred",
         E::Upgraded(_) => "Upgraded",
-        E::VerifyCiphertext(_) => "VerifyCiphertext",
+        E::ValidateInput(_) => "ValidateInput",
     }
 }
 
@@ -715,7 +715,7 @@ pub fn tfhe_result_handle(op: &TfheContractEvents) -> Option<Handle> {
         | E::OwnershipTransferStarted(_)
         | E::OwnershipTransferred(_)
         | E::Upgraded(_)
-        | E::VerifyCiphertext(_) => None,
+        | E::ValidateInput(_) => None,
     }
 }
 

host-contracts/codegen/hcuLimitGenerator.ts

@@ -347,11 +347,8 @@ contract HCULimit is UUPSUpgradeableEmptyProxy, Ownable2StepUpgradeable, ACLChec
      * @dev This function uses inline assembly to load the HCU from a specific storage location.
      */
     function _getHCUForHandle(bytes32 handle) internal view virtual returns (uint256 handleHCU) {
-        bytes32 slot = keccak256(abi.encodePacked(HCULimitStorageLocation, handle));
         assembly {
-            // Ensure the slot is properly aligned and validated before using tload.
-            // This assumes the slot is derived from a secure and deterministic process.
-            handleHCU := tload(slot)
+            handleHCU := tload(handle)
         }
     }
 
@@ -361,10 +358,8 @@ contract HCULimit is UUPSUpgradeableEmptyProxy, Ownable2StepUpgradeable, ACLChec
      * @dev This function uses inline assembly to store the HCU in a specific storage location.
      */
     function _getHCUForTransaction() internal view virtual returns (uint256 transactionHCU) {
-        /// @dev keccak256(abi.encodePacked(HCULimitStorageLocation, "HCU"))
-        bytes32 slot = 0x9fe02aa19e370f46d43dc2b6620733ba9c3b193659e9699f55eefe911af8a4b4;
         assembly {
-            transactionHCU := tload(slot)
+            transactionHCU := tload(0)
         }
     }
 
@@ -373,12 +368,11 @@ contract HCULimit is UUPSUpgradeableEmptyProxy, Ownable2StepUpgradeable, ACLChec
      * @notice Sets the HCU for a handle in the transient storage.
      * @param handle The handle for which to set the HCU.
      * @param handleHCU The HCU to set for the handle.
-     * @dev This function uses inline assembly to store the HCU in a specific storage location.
+     * @dev This function uses inline assembly to store the HCU in a specific transient storage slot.
      */
     function _setHCUForHandle(bytes32 handle, uint256 handleHCU) internal virtual {
-        bytes32 slot = keccak256(abi.encodePacked(HCULimitStorageLocation, handle));
         assembly {
-            tstore(slot, handleHCU)
+            tstore(handle, handleHCU)
         }
     }
 
@@ -387,13 +381,11 @@ contract HCULimit is UUPSUpgradeableEmptyProxy, Ownable2StepUpgradeable, ACLChec
     /**
      * @notice Updates the current HCU consumption for the transaction and stores it in the transient storage.
      * @param transactionHCU The total HCU for the transaction.
-     * @dev This function uses inline assembly to store the HCU in a specific storage location.
+     * @dev This function uses inline assembly to store the HCU in a specific transient storage slot.
      */
     function _setHCUForTransaction(uint256 transactionHCU) internal virtual {
-        /// @dev keccak256(abi.encodePacked(HCULimitStorageLocation, "HCU"))
-        bytes32 slot = 0x9fe02aa19e370f46d43dc2b6620733ba9c3b193659e9699f55eefe911af8a4b4;
         assembly {
-            tstore(slot, transactionHCU)
+            tstore(0, transactionHCU) // to avoid collisions with handles (see _setHCUForHandle)
         }
     }
 

host-contracts/codegen/templates.ts

@@ -267,7 +267,7 @@ function coprocessorInterfaceCustomFunctions(): string {
      * @param inputType       Input type.
      * @return result         Result.
      */
-    function verifyCiphertext(bytes32 inputHandle, address callerAddress, bytes memory inputProof, FheType inputType) external returns (bytes32 result);
+    function validateInput(bytes32 inputHandle, address callerAddress, bytes memory inputProof, FheType inputType) external returns (bytes32 result);
 
     /**
      * @notice          Performs the casting to a target type.
@@ -1138,20 +1138,13 @@ function generateSolidityDecryptionOracleMethods(fheTypes: AdjustedFheType[]): s
      * @notice  Warning: MUST be called directly in the callback function called by the relayer.
      * @notice Warning: this function never reverts, its boolean return value must be checked.
      * @dev The callback function has the following signature:
-     * - requestID (static uint256)
-     * - cleartexts (dynamic bytes)
-     * - decryptionProof (dynamic bytes)
-     *
-     * This means that the calldata is encoded in the following way:
-     * - 4 bytes: selector
-     * - 32 bytes: requestID
-     * - 32 bytes: offset of the cleartexts
-     * - 32 bytes: offset of the decryptionProof 
-     * - 32 bytes: length of the cleartexts (total number of bytes)
-     * - n*32 bytes: the "n" cleartext values, with "n" the number of handles
-     * - 32 bytes: length of the decryptionProof (total number of bytes)
-     * - ... the data of the decryptionProof (signatures, extra data)
-     */
+     * @dev   - requestID (static uint256)
+     * @dev   - cleartexts (dynamic bytes)
+     * @dev   - decryptionProof (dynamic bytes)
+     * @dev clearTexts is the abi-encoding of the list of all decrypted values assiociated to handlesList, in same order.
+     * @dev Only static native solidity types for clear values are supported, so clearTexts is the concatenation of all clear values appended to 32 bytes.
+     * @dev decryptionProof contains KMS signatures corresponding to clearTexts and associated handlesList, and needed metadata for KMS context.
+     **/
     function verifySignatures(
         bytes32[] memory handlesList,
         bytes memory cleartexts,
@@ -1206,7 +1199,7 @@ function generateCustomMethodsForImpl(): string {
         FheType toType
     ) internal returns (bytes32 result) {
         CoprocessorConfig storage $ = getCoprocessorConfig();
-        result = IFHEVMExecutor($.CoprocessorAddress).verifyCiphertext(inputHandle, msg.sender, inputProof, toType);
+        result = IFHEVMExecutor($.CoprocessorAddress).validateInput(inputHandle, msg.sender, inputProof, toType);
         IACL($.ACLAddress).allowTransient(result, msg.sender);
     }
 

host-contracts/contracts/FHEEvents.sol

@@ -26,7 +26,7 @@ contract FHEEvents {
     event FheMax(address indexed caller, bytes32 lhs, bytes32 rhs, bytes1 scalarByte, bytes32 result);
     event FheNeg(address indexed caller, bytes32 ct, bytes32 result);
     event FheNot(address indexed caller, bytes32 ct, bytes32 result);
-    event VerifyCiphertext(
+    event ValidateInput(
         address indexed caller,
         bytes32 inputHandle,
         address userAddress,