ENS contest - Fitraldys's results

1. useage of uint / int smaller than 32 bytes incurs overhead

When using elements that are smaller than 32 bytes, your contract’s gas usage may be higher. This is because the EVM operates on 32 bytes at a time. Therefore, if the element is smaller than that, the EVM must use more operations in order to reduce the size of the element from 32 bytes to the desired size.

resource : https://docs.soliditylang.org/en/v0.8.11/internals/layout_in_storage.html

Use a larger size then downcast where needed

POC :

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/dnssec-oracle/DNSSECImpl.sol#L58 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/dnssec-oracle/RRUtils.sol#L74 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/dnssec-oracle/RRUtils.sol#L75

2. Use Custom Error instead of Revert / Require String to Save Gas

Custom error from solidity 0.8.4 are cheaper than revert strings, custom error are defined using the error statement can use inside and outside the contract.

source https://blog.soliditylang.org/2021/04/21/custom-errors/

i suggest replacing revert / require error strings with custom error.

POC :

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/dnssec-oracle/RRUtils.sol#L307 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L101 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L139 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L198 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L234 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L240 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L242 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L261 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/registry/ReverseRegistrar.sol#L46 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/registry/ReverseRegistrar.sol#L54 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/BytesUtil.sol#L28 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/BytesUtil.sol#L42 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L62 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L87 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L109 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L176 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L179 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L197 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L199 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L202 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L202 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L217 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L248 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L249 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L252 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L292 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L322 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L327 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L354 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L359 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/Controllable.sol#L17

3. Require()/revert() strings longer than 32 bytes cost extra gas

Each extra chunk of byetes past the original 32

Resource :https://gist.github.com/hrkrshnn/ee8fabd532058307229d65dcd5836ddc#consider-having-short-revert-strings

POC :

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/registry/ReverseRegistrar.sol#L46 https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/Controllable.sol#L17