Rigor Protocol contest - 0xf15ers's results

1. ecrecover precompile internally checks if the value is 27 or 28. No need to check in the client side.

• Library SignatureDecoder uses if block to check the values for v.

 function recoverKey(
        bytes32 messageHash,
        bytes memory messageSignatures,
        uint256 pos
    ) internal pure returns (address) {
        if (messageSignatures.length % 65 != 0) {
            return (address(0));
        }

        uint8 v;
        bytes32 r;
        bytes32 s;
        (v, r, s) = signatureSplit(messageSignatures, pos);

        // If the version is correct return the signer address
        if (v != 27 && v != 28) { // @audit this check is performed by `ecrecover` internally 
            return (address(0));
 ..........           
}

reference: https://github.com/ethereum/yellowpaper/pull/860

2. Typecast to uint256 maynot be required

• _newTotalLent is of type uint256 and typecasting to same type again is not required.
• https://github.com/code-423n4/2022-08-rigor/blob/5ab7ea84a1516cb726421ef690af5bc41029f88f/contracts/Project.sol#L200

      uint256 _newTotalLent = totalLent + _cost;
        require(
            projectCost() >= uint256(_newTotalLent), // here 
            "Project::value>required"
        );

3. Adding a return statement when the function defines a named return variable is redundant.

• https://github.com/code-423n4/2022-08-rigor/blob/5ab7ea84a1516cb726421ef690af5bc41029f88f/contracts/HomeFi.sol#L307-L310

  function _msgSender()
        internal
        view
        override(ContextUpgradeable, ERC2771ContextUpgradeable)
        returns (address sender)
    {
        // We want to use the _msgSender() implementation of ERC2771ContextUpgradeable
        return super._msgSender();
        // sender = super._msgSender()
    }

4. Redundant assignment

• https://github.com/code-423n4/2022-08-rigor/blob/5ab7ea84a1516cb726421ef690af5bc41029f88f/contracts/Community.sol#L266
• Although it yields same result, code complexity can be reduced.

  _community.publishNonce = ++_community.publishNonce;
  //recommendation 
  // ++_community.publishNonce;