Canto Identity Subprotocols contest - Polaris_tow's results

REQUIRE() OR REVERT() STATEMENTS THAT CHECK INPUT ARGUMENTS SHOULD BE AT THE TOP OF THE FUNCTION

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-pfp-protocol/src/ProfilePicture.sol#L79-L82

    function mint(address _nftContract, uint256 _nftID) external {
        uint256 tokenId = ++numMinted;
        if (ERC721(_nftContract).ownerOf(_nftID) != msg.sender)
            revert PFPNotOwnedByCaller(msg.sender, _nftContract, _nftID);

USAGE OF UINT/INT SMALLER THAN 32 BYTES (256 BITS) 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. Each operation involving a uint8 costs an extra 22-28 gas (depending on whether the other operand is also a variable of type uint8) as compared to ones involving uint256, due to the compiler having to clear the higher bits of the memory word before operating on the uint8, as well as the associated stack operations of doing so. Use a larger size then downcast where needed. https://docs.soliditylang.org/en/v0.8.11/internals/layout_in_storage.html Use a larger size then downcast where needed. https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L34-L36 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L59-L63 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L73-L75

        uint8 tileOffset;
        /// @notice Emoji modifier for the skin tone. Can have values of 0 (yellow) and 1 - 5 (light to dark). Only supported by some emojis
        uint8 skinToneModifier;