//contracts/GatewayVM.sol

    function getStorage(Machine memory vm, uint256 slot) internal view returns (uint256) {
        bytes memory proof = vm.readProof();
|>      if (vm.storageRoot == NOT_A_CONTRACT) return 0;
        return uint256(vm.proofs.hooks.verifyStorageValue(vm.storageRoot, vm.target, slot, proof));
    }
//contracts/GatewayFetchTarget.sol
    function fetchCallback(bytes calldata response, bytes calldata carry) external view {
         //@audit if the passed carry is not sufficiently checked in a client contract that derives GatewayFetchTarget, ses.req can be modified to skip set target and artificially prove a storage slot is bytes32(0)
|>       Session memory ses = abi.decode(carry, (Session));
        (bytes[] memory values, uint8 exitCode) = ses.verifier.getStorageValues(ses.context, ses.req, response);
...
